[libpng17] Imported from libpng-1.7.0beta24.tar

instead of png_chunk_report(), which by default issues a warning
rather than an error, leading to later reading from a NULL pointer
(png_ptr->palette) in png_do_expand_palette().

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.6.0beta24 - June 7, 2012
+Libpng 1.7.0beta24 - December 15, 2013
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -9,379 +9,457 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.6.0beta24.tar.xz (LZMA-compressed, recommended)
-   1.6.0beta24.tar.gz
-   1.6.0beta24.tar.bz2
+   1.7.0beta24.tar.xz (LZMA-compressed, recommended)
+   1.7.0beta24.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp160b24.7z  (LZMA-compressed, recommended)
-   lp160b24.zip
+   lp170b24.7z  (LZMA-compressed, recommended)
+   lp170b24.zip
 
 Other information:
 
-   1.6.0beta24-README.txt
-   1.6.0beta24-LICENSE.txt
+   1.7.0beta24-README.txt
+   1.7.0beta24-LICENSE.txt
+   Gnupg/*.asc (PGP armored detached signatures)
 
-Changes since the last public release (1.5.7):
+Changes since the last public release (1.6.0):
 
-Version 1.6.0beta01 [December 15, 2011]
-  Removed machine-generated configure files from the GIT repository (they will
-    continue to appear in the tarball distributions).
-  Restored the new 'simplified' API, which was started in libpng-1.5.7beta02
-    but later deleted from libpng-1.5.7beta05.
-  Added example programs for the new 'simplified' API.
-  Added ANSI-C (C90) headers and require them, and take advantage of the
-    change. Also fixed some of the projects/* and contrib/* files that needed
-    updates for libpng16 and the move of pngvalid.c.
-    With this change the required ANSI-C header files are assumed to exist: the
-    implementation must provide float.h, limits.h, stdarg.h and stddef.h and
-    libpng relies on limits.h and stddef.h existing and behaving as defined
-    (the other two required headers aren't used).  Non-ANSI systems that don't
-    have stddef.h or limits.h will have to provide an appropriate fake
-    containing the relevant types and #defines.
-  The use of FAR/far has been eliminated and the definition of png_alloc_size_t
-    is now controlled by a flag so that 'small size_t' systems can select it
-    if necessary.  Libpng 1.6 may not currently work on such systems -- it
-    seems likely that it will ask 'malloc' for more than 65535 bytes with any
-    image that has a sufficiently large row size (rather than simply failing
-    to read such images).
-  New tools directory containing tools used to generate libpng code.
-  Fixed race conditions in parallel make builds. With higher degrees of
-    parallelism during 'make' the use of the same temporary file names such
-    as 'dfn*' can result in a race where a temporary file from one arm of the
-    build is deleted or overwritten in another arm.  This changes the
-    temporary files for suffix rules to always use $* and ensures that the
-    non-suffix rules use unique file names.
+Version 1.7.0alpha01 [December 15, 2012]
+  Started 1.7.0 branch from libpng-1.6.0beta33.
+  Made 8-bit compose and rgb_to_grayscale accuracy improvements.  These
+    changes cause 16-bit arithmetic to be used for 8-bit data in the gamma
+    corrected compose and grayscale operations.  The arithmetic errors have
+    three sources all of which are fixed in this commit:
+    1) 8-bit linear calculations produce massive errors for lower intensity
+       values.
+    2) The old 16-bit "16 to 8" gamma table code erroneously wrote the lowest
+       output value into a table entry which corresponded to multiple output
+       values (so where the value written should have been the closest to the
+       transformed input value.)
+    3) In a number of cases the code to access the 16-bit table did not round;
+       it did a simple shift, which was wrong and made the side effects of (2)
+       even worse.
+  The new gamma code does not have the 16-to-8 problem at the cost of slightly
+    more calculations and the algorithm used to minimize the number of
+    calculations has been extended to all the 16-bit tables; it has advantages
+    for any significant gamma correction.
+  Rearranged png_struct, remove unused members, change png_set_filter handling
+    png_struct members rearranged - partly to reorder to avoid packing, partly
+    to put frequently accessed members at the start and partly to make
+    the grouping more clear. png_set_filter code has been rewritten and the
+    code shared with png_write_start_row moved to a common function.  Comments
+    in png.h have been made more clear. Minor fixes to
+    contrib/libtests/timepng.c and some of the png_*_tRNS logic, including
+    more error detection in png_set_tRNS.
+  Cleaned up USER_LIMITS feature, removing members from png_struct when not
+    required.
+  Rearranged ARM-NEON optimizations to isolate the machine specific code to
+    the hardware subdirectory, and add comments to pngrutil.c so that
+    implementors of other optimizations will know what to do.
+  Fixed cases of unquoted DESTDIR in Makefile.am.
+  Rebuilt Makefile.in, configure, etc., with autoconf-2.69 and automake-1.12.5.
 
-Version 1.6.0beta02 [December 21, 2011]
-  Correct configure builds where build and source directories are separate.
-    The include path of 'config.h' was erroneously made relative in pngvalid.c
-    in libpng 1.5.7.
+Version 1.7.0alpha02 [December 17, 2012]
+  Removed functions that were deprecated in libpng-1.6.0:
+    png_reset_zstream(), png_info_init_3(), and png_data_freer() and its
+    associated flags.
+  Removed some duplicated lines from contrib/tools/scale.c and png.c.
+  Changed some instances of png_warning() to png_app_error().
+  Updated some left over "1.6.0beta32" in code sources.
+  Fixed a "png_structp" prototype (should be png_structrp) in arm_init.c
+  Updated the version-number hack in pngvalid.c
 
-Version 1.6.0beta03 [December 22, 2011]
-  Start-up code size improvements, error handler flexibility. These changes
-    alter how the tricky allocation of the initial png_struct and png_info
-    structures are handled. png_info is now handled in pretty much the same
-    way as everything else, except that the allocations handle NULL return
-    silently.  png_struct is changed in a similar way on allocation and on
-    deallocation a 'safety' error handler is put in place (which should never
-    be required).  The error handler itself is changed to permit mismatches
-    in the application and libpng error buffer size; however, this means a
-    silent change to the API to return the jmp_buf if the size doesn't match
-    the size from the libpng compilation; libpng now allocates the memory and
-    this may fail.  Overall these changes result in slight code size
-    reductions; however, this is a reduction in code that is always executed
-    so is particularly valuable.  Overall on a 64-bit system the libpng DLL
-    decreases in code size by 1733 bytes.  pngerror.o increases in size by
-    about 465 bytes because of the new functionality.
+Version 1.7.0alpha03 [December 19, 2012]
+  Cleaned up and enhanced the configure option; libpng now correctly
+    links and tests against zlib with a prefix; tests have been clarified; and
+    irrelevant or obsolete things (as defined by the autotools man page) have
+    been removed.
+  Documented new PNG_ABORT behavior in the manual and commentary in pngerror.c
+  Cleaned up whitespace in the synopsis portion of the manpage "libpng.3"
+  Fixed previous support for Z_PREFIX in configure builds, corrected sCAL APIs;
+    some of these use floating point arithmetic so they need to be disabled if
+    floating point arithmetic is switched off.  This is a quiet API change -
+    previously it appeared that the APIs were supported if fixed point
+    arithmetic was used internally, however they required certain APIs (floor,
+    modf, frexp, atof) that are part of C floating point support. Changed
+    png_fixed and the gamma code specific version of the same to avoid floor(),
+    which may be a library function (not an intrinsic). Removed unused #if 0
+    code.
+  Disassembled the version number in scripts/options.awk (necessary for
+    building on SunOs).
 
-Version 1.6.0beta04 [December 30, 2011]
-  Regenerated configure scripts with automake-1.11.2
-  Eliminated png_info_destroy(). It is now used only in png.c and only calls
-    one other internal function and memset().
-  Enabled png_get_sCAL_fixed() if floating point APIs are enabled. Previously
-    it was disabled whenever internal fixed point arithmetic was selected,
-    which meant it didn't exist even on systems where FP was available but not
-    preferred.
-  Added pngvalid.c compile time checks for const APIs.
-  Implemented 'restrict' for png_info and png_struct. Because of the way
-    libpng works both png_info and png_struct are always accessed via a
-    single pointer.  This means adding C99 'restrict' to the pointer gives
-    the compiler some opportunity to optimize the code.  This change allows
-    that.
-  Moved AC_MSG_CHECKING([if libraries can be versioned]) later to the proper
-    location in configure.ac (Gilles Espinasse).
-  Changed png_memcpy to C assignment where appropriate. Changed all those
-    uses of png_memcpy that were doing a simple assignment to assignments
-    (all those cases where the thing being copied is a non-array C L-value).
-  Added some error checking to png_set_*() routines.
-  Removed the reference to the non-exported function png_memcpy() from
-    example.c.
-  Fixed the Visual C 64-bit build - it requires jmp_buf to be aligned, but
-    it had become misaligned.
-  Revised contrib/pngminus/pnm2png.c to avoid warnings when png_uint_32
-    and unsigned long are of different sizes.
+Version 1.7.0alpha04 [December 23, 2012]
+  Added scripts/makefile.msys contributed by Christopher M. Wheeler
+  Made default Zlib compression settings be configurable. This adds #defines to
+    pnglibconf.h to control the defaults.
+  Fixed Windows build issues, enabled ARM compilation. Various warnings issued
+    by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old
+    GCCs.) ARM support is enabled by default in zlib.props (unsupported by
+    Microsoft) and ARM compilation is made possible by deleting the check for
+    x86. The test programs cannot be run because they are not signed.
 
-Version 1.6.0beta05 [January 15, 2012]
-  Updated manual with description of the simplified API (copied from png.h)
-  Fix bug in pngerror.c: some long warnings were being improperly truncated
-    (CVE-2011-3464, bug introduced in libpng-1.5.3beta05).
+Version 1.7.0alpha05 [December 24, 2012]
+  Discontinued distributing libpng-1.x.x.tar.bz2.
+  Discontinued distributing libpng-1.7.0-1.6.0-diff.txt and similar.
 
-Version 1.6.0beta06 [January 24, 2012]
-  Added palette support to the simplified APIs. This commit
-    changes some of the macro definitions in png.h, app code
-    may need corresponding changes.
-  Increased the formatted warning buffer to 192 bytes.
-  Added color-map support to simplified API. This is an initial version for
-    review; the documentation has not yet been updated.
-  Fixed Min/GW uninstall to remove libpng.dll.a
+Version 1.7.0alpha06 [January 1, 2013]
+  Fixed 'make distcheck' on SUN OS - libpng.so was not being removed
 
-Version 1.6.0beta07 [January 28, 2012]
-  Eliminated Intel icc/icl compiler warnings. The Intel (GCC derived)
-    compiler issues slightly different warnings from those issued by the
-    current vesions of GCC. This eliminates those warnings by
-    adding/removing casts and small code rewrites.
-  Updated configure.ac from autoupdate: added --enable-werror option.
-    Also some layout regularization and removal of introduced tab characters
-    (replaced with 3-character indentation).  Obsolete macros identified by
-    autoupdate have been removed; the replacements are all in 2.59 so
-    the pre-req hasn't been changed.  --enable-werror checks for support
-    for -Werror (or the given argument) in the compiler.  This mimics the
-    gcc configure option by allowing -Werror to be turned on safely; without
-    the option the tests written in configure itself fail compilation because
-    they cause compiler warnings.
-  Rewrote autogen.sh to run autoreconf instead of running tools one-by-one.
-  Conditionalize the install rules for MINGW and CYGWIN in CMakeLists.txt and
-    set CMAKE_LIBRARY_OUTPUT_DIRECTORY to "lib" on all platforms (C. Yapp).
-  Freeze libtool files in the 'scripts' directory. This version of autogen.sh
-    attempts to dissuade people from running it when it is not, or should not,
-    be necessary.  In fact, autogen.sh does not work when run in a libpng
-    directory extracted from atar distribution anymore. You must run it in
-    a GIT clone instead.
-  Added two images to contrib/pngsuite (1-bit and 2-bit transparent grayscale),
-    and renamed three whose names were inconsistent with those in
-    pngsuite/README.txt.
+Version 1.7.0alpha07 [January 10, 2013]
+  Fixed conceivable but difficult to repro overflow. Also added two test
+    programs to generate and test a PNG which should have the problem.
 
-Version 1.6.0beta08 [February 1, 2012]
-  Fixed Image::colormap misalignment in pngstest.c
-  Check libtool/libtoolize version number (2.4.2) in configure.ac
-  Divide test-pngstest.sh into separate pngstest runs for basic and
-    transparent images.
-  Moved automake options to AM_INIT_AUTOMAKE in configure.ac
-  Added color-tests, silent-rules (Not yet implemented in Makefile.am) and
-    version checking to configure.ac
-  Improved pngstest speed by not doing redundant tests and add const to
-    the background parameter of png_image_finish_read. The --background
-    option is now done automagically only when required, so that commandline
-    option no longer exists.
-  Cleaned up pngpriv.h to consistently declare all functions and data.
-    Also eliminated PNG_CONST_DATA, which is apparently not needed but we
-    can't be sure until it is gone.
-  Added symbol prefixing that allows all the libpng external symbols
-    to be prefixed (suggested by Reuben Hawkins).
-  Updated "ftbb*.png" list in the owatcom and vstudio projects.
-  Fixed 'prefix' builds on clean systems. The generation of pngprefix.h
-    should not require itself.
-  Updated INSTALL to explain that autogen.sh must be run in a GIT clone,
-    not in a libpng directory extracted from a tar distribution.
+Version 1.7.0alpha08 [January 17, 2013]
+  Corrected previous attempt at overflow detection in png_set_unknown_chunks().
 
-Version 1.6.0beta09 [February 1, 2012]
-  Reverted the prebuilt configure files to libpng-1.6.0beta05 condition.
+Version 1.7.0alpha09 [January 21, 2013]
+  Pulled changes to multi-chunk handling from libpng-1.6.0beta40.
 
-Version 1.6.0beta10 [February 3, 2012]
-  Added Z_SOLO for zlib-1.2.6+ and correct pngstest tests
-  Updated list of test images in CMakeLists.txt
-  Updated the prebuilt configure files to current condition.
-  Revised INSTALL information about autogen.sh; it works in tar distributions.
+Version 1.7.0alpha10 [February 5, 2013]
+  Make symbol prefixing work with the ARM neon optimizations. Also
+    allow pngpriv.h to be included for preprocessor definitions only, so
+    it can be used in non-C/C++ files.
+  Added png_get_palette_max() function.
+  Changed png_size_t to size_t throughout headers, make sRGB check numbers
+    consistent.
+  Fixed ARM support (Mans Rullgard).
+  Removed stray out-of-order #endif and #ifdef (Mans Rullgard).
+  Ported libpng 1.5 options.awk/dfn file handling to 1.7, fixed one bug.
+  Rebuilt Makefile.in, configure, etc., with autoconf-2.69 and automake-1.13.
+  Minor fixes to assembler changes, verified with a dummy .S file
+  Removed cc -E workround, corrected png_get_palette_max API. Tested on
+    SUN OS cc 5.9, which demonstrates the tokenization problem previously
+    avoided by using /lib/cpp.  Since all .dfn output is now protected
+    in double quotes unless it is to be macro substituted the fix should work
+    everywhere.
 
-Version 1.6.0beta11 [February 16, 2012]
-  Fix character count in pngstest command in projects/owatcom/pngstest.tgt
-  Revised test-pngstest.sh to report PASS/FAIL for each image.
-  Updated documentation about the simplified API.
-  Corrected estimate of error in libpng png_set_rgb_to_gray API.  The API is
-    extremely inaccurate for sRGB conversions because it uses an 8-bit
-    intermediate linear value and it does not use the sRGB transform, so it
-    suffers from the known instability in gamma transforms for values close
-    to 0 (see Poynton).  The net result is that the calculation has a maximum
-    error of 14.99/255; 0.5/255^(1/2.2).  pngstest now uses 15 for the
-    permitted 8-bit error. This may still not be enough because of arithmetic
-    error.
-  Removed some unused arrays (with #ifdef) from png_read_push_finish_row().
-  Fixed a memory overwrite bug in simplified read of RGB PNG with
-    non-linear gamma Also bugs in the error checking in pngread.c and changed
-    quite a lot of the checks in pngstest.c to be correct; either correctly
-    written or not over-optimistic.  The pngstest changes are insufficient to
-    allow all possible RGB transforms to be passed; pngstest cmppixel needs
-    to be rewritten to make it clearer which errors it allows and then changed
-    to permit known inaccuracies.
-  Removed tests for no-longer-used *_EMPTY_PLTE_SUPPORTED from pngstruct.h
-  Fixed fixed/float API export conditionals. 1) If FIXED_POINT or
-    FLOATING_POINT options were switched off, png.h ended up with lone ';'
-    characters.  This is not valid ANSI-C outside a function.  The ';'
-    characters have been moved inside the definition of PNG_FP_EXPORT and
-    PNG_FIXED_EXPORT. 2) If either option was switched off, the declaration
-    of the corresponding functions were completely omitted, even though some
-    of them are still used internally.  The result is still valid, but
-    produces warnings from gcc with some warning options (including -Wall). The
-    fix is to cause png.h to declare the functions with PNG_INTERNAL_FUNCTION
-    when png.h is included from pngpriv.h.
-  Check for invalid palette index while reading paletted PNG.  When one is
-    found, issue a warning and increase png_ptr->num_palette accordingly.
-    Apps are responsible for checking to see if that happened.
+Version 1.7.0beta01 [February 15, 2013]
+  Enable parallel tests and rearrange TESTS order to take advantage of
+    the massive speed improvements use a make capable of parallel builds
+    on a multi-CPU machine and pass the right arguments to make (-j10000
+    for GNU make) to get the build to run in parallel.
+  Fixed previous support for Z_PREFIX in configure builds, corrected
+    sCAL APIs; some of these use floating point arithmetic so need to be
+    disabled if floating point arithmetic is switched off.  This is a quiet API
+    change - previously it appeared that the APIs were supported if fixed point
+    arithmetic was used internally, however they required certain APIs (floor,
+    modf, frexp, atof) that are part of C floating point support. Changed
+    png_fixed and the gamma code specific version of the same to avoid floor(),
+    which may be a library function (not an intrinsic). Removed unused #if 0
+    code.
+  Fixed make distcheck to skip over the test result files. They were
+    being included because the whole of the 'tests' directory is included,
+    fixed to just include the actual test files and tests/pngstest.  Also
+    reverted the previous erroneous change to remove the ${srcdir} from the
+    front of contrib, scripts, projects and added an explanation of what is
+    going on to Makefile.am
+  Fixed missing dependency in --prefix builds. The intermediate
+    internal 'prefix.h' file can only be generated correctly after pnglibconf.h,
+    however the dependency was not in Makefile.am.  The symptoms are
+    unpredictable depending on the order make chooses to build pngprefix.h and
+    pnglibconf.h, often the error goes unnoticed because there is a system
+    pnglibconf.h to use instead.
+  Accept "," as a separator in pnglibconf.dfa and allow for
+    continuation lines. This adds to the syntax of "option" and "chunk" lines,
+    allowing the elements to be separated by a "," at the end of an element and
+    interpreting a "," at end of line as a continuation - so the following line
+    is read.  The new syntax is optional and solely provided for readability.
+  Enclosed the new png_get_palette_max in #ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+    block, and revised pnglibconf.h and pnglibconf.h.prebuilt accordingly.
 
-Version 1.6.0beta12 [February 18, 2012]
-  Do not increase num_palette on invalid_index.
-  Relocated check for invalid palette index to pngrtran.c, after unpacking
-    the sub-8-bit pixels.
-  Fixed CVE-2011-3026 buffer overrun bug.  Deal more correctly with the test
-    on iCCP chunk length. Also removed spurious casts that may hide problems
-    on 16-bit systems.
+Version 1.7.0beta02 [February 18, 2013]
+  Fixed a race condition in the creation of the build 'scripts' directory
+    while building with a parallel make.
+  Use approved/supported Android method to check for NEON, use Linux/POSIX
+    1003.1 API to check /proc/self/auxv avoiding buffer allocation and other
+    library calls (ported from libpng15).
+  Use parentheses more consistently in "#if defined(MACRO)" tests.
+  Folded long lines.
 
-Version 1.6.0beta13 [February 24, 2012]
-  Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from
-    pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
-    now that png_ptr->buffer is inaccessible to applications, the special
-    handling is no longer useful.
-  Added PNG_SAFE_LIMITS feature to pnglibconf.dfa, pngpriv.h, and new
-    pngusr.dfa to reset the user limits to safe ones if PNG_SAFE_LIMITS is
-    defined.  To enable, use "CPPFLAGS=-DPNG_SAFE_LIMITS_SUPPORTED=1" on the
-    configure command or put #define PNG_SAFE_LIMITS_SUPPORTED in
-    pnglibconf.h.prebuilt and pnglibconf.h.
+Version 1.7.0beta03 [February 22, 2013]
+  Reenabled code to allow zero length PLTE chunks for MNG.
+  Fixed ALIGNED_MEMORY support.
+  Allow run-time ARM NEON checking to be disabled. A new configure option:
+    --enable-arm-neon=always will stop the run-time checks. New checks
+    within arm/arm_init.c will cause the code not to be compiled unless
+    __ARM_NEON__ is set. This should make it fail safe (if someone asks
+    for it on then the build will fail if it can't be done.)
+  Updated the INSTALL document.
 
-Version 1.6.0beta14 [February 27, 2012]
-  Added information about the new limits in the manual.
-  Updated Makefile.in
+Version 1.7.0beta04 [February 27, 2013]
+  Revised INSTALL to recommend using CPPFLAGS instead of INCLUDES.
+  Revised scripts/makefile.freebsd to respect ZLIBLIB and ZLIBINC.
+  Revised scripts/dfn.awk to work with the buggy MSYS awk that has trouble
+    with CRLF line endings.
 
-Version 1.6.0beta15 [March 2, 2012]
-  Removed unused "current_text" members of png_struct and the png_free()
-    of png_ptr->current_text from pngread.c
-  Rewrote pngstest.c for substantial speed improvement.
-  Fixed transparent pixel and 16-bit rgb tests in pngstest and removed a
-    spurious check in pngwrite.c
-  Added PNG_IMAGE_FLAG_FAST for the benefit of applications that store
-    intermediate files, or intermediate in-memory data, while processing
-    image data with the simplified API.  The option makes the files larger
-    but faster to write and read.  pngstest now uses this by default; this
-    can be disabled with the --slow option.
-  Improved pngstest fine tuning of error numbers, new test file generator.
-    The generator generates images that test the full range of sample values,
-    allow the error numbers in pngstest to be tuned and checked.  makepng
-    also allows generation of images with extra chunks, although this is
-    still work-in-progress.
-  Added tests for invalid palette index while reading and writing (work in
-    progress, the latter isn't finished).
-  Fixed some bugs in ICC profile writing. The code should now accept
-    all potentially valid ICC profiles and reject obviously invalid ones.
-    It now uses png_error() to do so rather than casually writing a PNG
-    without the necessary color data.
-  Removed whitespace from the end of lines in all source files and scripts.
+Version 1.7.0beta05 [March 5, 2013]
+  Avoid a possible memory leak in contrib/gregbook/readpng.c
+  Changed user chunk callback API to respect global and per chunk defaults.
+    Previously a return of 0 from a user chunk callback would result in the
+    chunk being saved (if this was safe, even if the chunk was unsafe-to-copy);
+    this change respects the defaults set by the application, so unknown chunks
+    can be discarded by default and known-safe ones preserved.
+  Corrected Android builds and corrected libpng.vers with symbol
+    prefixing. This adds an API to set optimization options externally,
+    providing an alternative and general solution for the non-portable
+    run-time tests used by the ARM Neon code.  It also makes those tests
+    compile and link on Android.  The order of settings vs options in
+    pnglibconf.h is reversed to allow settings to depend on options and
+    options can now set (or override) the defaults for settings.
 
-Version 1.6.0beta16 [March 6, 2012]
-  Relocated palette-index checking function from pngrutil.c to pngtrans.c
-  Added palette-index checking while writing.
-  Changed png_inflate() and calling routines to avoid overflow problems.
-    This is an intermediate check-in that solves the immediate problems and
-    introduces one performance improvement (avoiding a copy via png_ptr->zbuf.)
-    Further changes will be made to make ICC profile handling more secure.
-  Fixed build warnings (MSVC, GCC, GCC v3). Cygwin GCC with default options
-    declares 'index' as a global, causing a warning if it is used as a local
-    variable.  GCC 64-bit warns about assigning a (size_t) (unsigned 64-bit)
-    to an (int) (signed 32-bit).  MSVC, however, warns about using the
-    unary '-' operator on an unsigned value (even though it is well defined
-    by ANSI-C to be ~x+1).  The padding calculation was changed to use a
-    different method.  Removed the tests on png_ptr->pass.
-  Added contrib/libtests/tarith.c to test internal arithmetic functions from
-    png.c. This is a libpng maintainer program used to validate changes to the
-    internal arithmetic functions.
-  Made read 'inflate' handling like write 'deflate' handling. The read
-    code now claims and releases png_ptr->zstream, like the write code.
-    The bug whereby the progressive reader failed to release the zstream
-    is now fixed, all initialization is delayed, and the code checks for
-    changed parameters on deflate rather than always calling
-    deflatedEnd/deflateInit.
-  Validate the zTXt strings in pngvalid.
-  Added code to validate the windowBits value passed to deflateInit2().
-    If the call to deflateInit2() is wrong a png_warning will be issued
-    (in fact this is harmless, but the PNG data produced may be sub-optimal).
+Version 1.7.0beta06 [March 13, 2013]
+  Corrected simplified API default gamma for color-mapped output, added
+    a flag to change default. In 1.6.0 when the simplified API was used
+    to produce color-mapped output from an input image with no gamma
+    information the gamma assumed for the input could be different from
+    that assumed for non-color-mapped output.  In particular 16-bit depth
+    input files were assumed to be sRGB encoded, whereas in the 'direct'
+    case they were assumed to have linear data.  This was an error.  The
+    fix makes the simplified API treat all input files the same way and
+    adds a new flag to the png_image::flags member to allow the
+    application/user to specify that 16-bit files contain sRGB data
+    rather than the default linear.
+  Fixed bugs in the pngpixel and makepng test programs.
+  Fixed CMakelists.txt to allow building a single variant of the library
+    (Claudio Bley):
+  Introduced a PNG_LIB_TARGETS variable that lists all activated library
+    targets.  It is an error if this variable ends up empty, ie. you have
+    to build at least one library variant.
+  Made the *_COPY targets only depend on library targets actually being build.
+  Use PNG_LIB_TARGETS to unify a code path.
+  Changed the CREATE_SYMLINK macro to expect the full path to a file as the
+    first argument. When symlinking the filename component of that path is
+    determined and used as the link target.
+  Use copy_if_different in the CREATE_SYMLINK macro.
+  Eliminated two warnings from the Intel C compiler. The warnings are
+    technically valid, although a reasonable treatment of division would
+    show it to be incorrect.
 
-Version 1.6.0beta17 [March 10, 2012]
-  Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition. 
-  Reject all iCCP chunks after the first, even if the first one is invalid.
-  Deflate/inflate was reworked to move common zlib calls into single
-    functions [rw]util.c.  A new shared keyword check routine was also added
-    and the 'zbuf' is no longer allocated on progressive read.  It is now
-    possible to call png_inflate() incrementally.
-  If benign errors are disabled use maximum window on ancilliary inflate.
-    This works round a bug introduced in 1.5.4 where compressed ancillary
-    chunks could end up with a too-small windowBits value in the deflate
-    header.
+Version 1.7.0beta07 [April 14, 2013]
+  Updated documentation of 1.5.x to 1.6.x changes in iCCP chunk handling.
+  Fixed incorrect warning of excess deflate data. End condition - the
+    warning would be produced if the end of the deflate stream wasn't read
+    in the last row.  The warning is harmless.
+  Corrected the test on user transform changes on read. It was in the
+    png_set of the transform function, but that doesn't matter unless the
+    transform function changes the rowbuf size, and that is only valid if
+    transform_info is called.
+  Corrected a misplaced closing bracket in contrib/libtests/pngvalid.c
+    (Flavio Medeiros).
+  Corrected length written to uncompressed iTXt chunks (Samuli Suominen).
 
-Version 1.6.0beta18 [March 16, 2012]
-  Issue a png_benign_error() instead of png_warning() about bad palette index.
-  In pngtest, treat benign errors as errors if "-strict" is present.
-  Fixed an off-by-one error in the palette index checking function.
-  Fixed a compiler warning under Cygwin (Windows-7, 32-bit system)
-  Revised example.c to put text strings in a temporary character array
-    instead of directly assigning string constants to png_textp members.
-    This avoids compiler warnings when -Wwrite-strings is enabled.
-  Added output flushing to aid debugging under Visual Studio. Unfortunately
-    this is necessary because the VS2010 output window otherwise simply loses
-    the error messages on error (they weren't flushed to the window before
-    the process exited, apparently!)
-  Added configuration support for benign errors and changed the read
-    default. Also changed some warnings in the iCCP and sRGB handling
-    from to benign errors. Configuration now makes read benign
-    errors warnings and write benign errors to errors by default (thus
-    changing the behavior on read).  The simplified API always forces
-    read benign errors to warnings (regardless of the system default, unless
-    this is disabled in which case the simplified API can't be built.)
+Version 1.7.0beta08 [April 18, 2013]
+  Added contrib/tools/fixitxt.c, to repair the erroneous iTXt chunk length
+    written by libpng-1.6.0 and 1.6.1.
+  Disallow storing sRGB information when the sRGB is not supported.
 
-Version 1.6.0beta19 [March 18,2012]
-  Work around for duplicate row start calls; added warning messages.
-    This turns on PNG_FLAG_DETECT_UNINITIALIZED to detect app code that
-    fails to call one of the 'start' routines (not enabled in libpng-1.5
-    because it is technically an API change, since it did normally work
-    before.)  It also makes duplicate calls to png_read_start_row (an
-    internal function called at the start of the image read) benign, as
-    they were before changes to use png_inflate_claim. Somehow webkit is
-    causing this to happen; this is probably a mis-feature in the zlib
-    changes so this commit is only a work-round.
-  Removed erroneous setting of DETECT_UNINITIALIZED and added more
-    checks. The code now does a png_error if an attempt is made to do the
-    row initialization twice; this is an application error and it has
-    serious consequences because the transform data in png_struct is
-    changed by each call.
-  Added application error reporting and added chunk names to read
-    benign errors; also added --strict to pngstest - not enabled
-    yet because a warning is produced.
-  Avoid the double gamma correction warning in the simplified API.
-    This allows the --strict option to pass in the pngstest checks
+Version 1.7.0beta09 [April 24, 2013]
+  Exposed PNG chunk types in png.h
+  Modified png_uint_32 macros/code to make as few assumptions as possible
+  Revised stack marking in arm/filter_neon.S and configure.ac
+  Ensure that NEON filter stuff is completely disabled when switched 'off'.
+    Previously the ARM NEON specific files were still built if the option
+    was switched 'off' as opposed to being explicitly disabled.
 
-Version 1.6.0beta20 [March 29, 2012]
-  Changed chunk handler warnings into benign errors, incrementally load iCCP
-  Added checksum-icc.c to contrib/tools
-  Prevent PNG_EXPAND+PNG_SHIFT doing the shift twice.
-  Recognize known sRGB ICC profiles while reading; prefer writing the
-    iCCP profile over writing the sRGB chunk, controlled by the
-    PNG_sRGB_PROFILE_CHECKS option.
-  Revised png_set_text_2() to avoid potential memory corruption (fixes
-    CVE-2011-3048).
+Version 1.7.0beta10 [April 24, 2013]
+  Attempt to fix the PNG_ARM_NEON configuration mess.
 
-Version 1.6.0beta21 [April 27, 2012]
-  Revised scripts/makefile.darwin: use system zlib; remove quotes around
-    architecture list; add missing ppc architecture; add architecture options
-    to shared library link; don't try to create a shared lib based on missing
-    RELEASE variable.
-  Enable png_set_check_for_invalid_index() for both read and write.
-  Removed #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED in pngpriv.h around
-    declaration of png_handle_unknown().
-  Added -lssp_nonshared in a comment in scripts/makefile.freebsd
-    and changed deprecated NOOBJ and NOPROFILE to NO_OBJ and NO_PROFILE.
+Version 1.7.0beta11 [April 26, 2013]
+  Test for 'arm*', not just 'arm' in the host_cpu configure variable.
 
-Version 1.6.0beta22 [May 23, 2012]
-  Removed need for -Wno-cast-align with clang.  clang correctly warns on
-    alignment increasing pointer casts when -Wcast-align is passed. This
-    fixes the cases that clang warns about either by eliminating the
-    casts from png_bytep to png_uint_16p (pngread.c), or, for pngrutil.c
-    where the cast is previously verified or pngstest.c where it is OK, by
-    introducing new png_aligncast macros to do the cast in a way that clang
-    accepts.
+Version 1.7.0beta12 [April 30, 2013]
+  Added png_app_warning for out-of-range unknown chunk index in
+    png_set_unknown_chunk_location().
+  Expanded manual paragraph about writing private chunks.
+  Avoid dereferencing NULL pointer possibly returned from
+     png_create_write_struct() (Andrew Church).
 
-Version 1.6.0beta23 [June 6, 2012]
-  Revised CMakeLists.txt to not attempt to make a symlink under mingw.
-  Made fixes for new optimization warnings from gcc 4.7.0. The compiler
-    performs an optimization which is safe; however it then warns about it.
-    Changing the type of 'palette_number' in pngvalid.c removes the warning.
-  Do not depend upon a GCC feature macro being available for use in generating
-    the linker mapfile symbol prefix.
-  Improved performance of new do_check_palette_indexes() function (only
-    update the value when it actually increases, move test for whether
-    the check is wanted out of the function.
+Version 1.7.0beta13 [May 12, 2013]
+  Revised contrib/pngminim/*/makefile to generate pnglibconf.h with the
+    right zlib header files.
+  Separated CPPFLAGS and CFLAGS in contrib/pngminim/*/makefile
+  Updated contrib/pngminus/pnm2png.c (Paul Stewart):
+    Check for EOF
+    Ignore "#" delimited comments in input file to pnm2png.c.
+    Fixed whitespace handling
+    Added a call to png_set_packing()
+    Initialize dimension values so if sscanf fails at least we have known
+      invalid values.
+  Calculate our own zlib windowBits when decoding rather than trusting the
+    CMF bytes in the PNG datastream.
+  Added an option to force maximum window size for inflating, which was
+    the behavior of libpng15 and earlier.
+  Added png-fix-itxt and png-fix-too-far-back to the built programs and
+    removed warnings from the source code and timepng that are revealed as
+    a result.
+  Detect wrong libpng versions linked to png-fix-too-far-back, which currently
+    only works with libpng versions that can be made to reliably fail when
+    the deflate data contains an out-of-window reference.  This means only
+    1.6 and later.
+  Attempt to detect configuration issues with png-fix-too-far-back, which
+    requires both the correct libpng and the correct zlib to function
+    correctly.
+  Check ZLIB_VERNUM for mismatches, enclose #error in quotes
+  Added information in the documentation about problems with and fixes for
+    the bad CRC and bad iTXt chunk situations.
 
-Version 1.6.0beta24 [June 7, 2012]
-  Don't check palette indexes if num_palette is 0 (as it can be in MNG files).
+Version 1.7.0beta14 [June 8, 2013]
+  Removed a redundant test in png_set_IHDR().
+  Added set(CMAKE_CONFIGURATION_TYPES ...) to CMakeLists.txt (Andrew Hundt)
+  Deleted set(CMAKE_BUILD_TYPE) block from CMakeLists.txt
+  Enclose the prototypes for the simplified write API in #ifdef STDIO/#endif
+  Make ARM NEON support work at compile time (not just configure time).
+    This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when
+    using a compiler that compiles for multiple architectures at one time.
+  Removed PNG_FILTER_OPTIMIZATIONS and PNG_ARM_NEON_SUPPORTED from
+    pnglibconf.h, allowing more of the decisions to be made internally
+    (pngpriv.h) during the compile.  Without this, symbol prefixing is broken
+    under certain circumstances on ARM platforms.  Now only the API parts of
+    the optimizations ('check' vs 'api') are exposed in the public header files
+    except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
+    decision about whether or not to use the optimizations.
+  Protect symbol prefixing against CC/CPPFLAGS/CFLAGS useage.
+    Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
+    on __ARM_NEON__ from configure time to compile time.  This breaks symbol
+    prefixing because the definition of the special png_init_filter_functions
+    call was hidden at configure time if the relevant compiler arguments are
+    passed in CFLAGS as opposed to CC.  This change attempts to avoid all
+    the confusion that would result by declaring the init function even when
+    it is not used, so that it will always get prefixed.
+
+Version 1.7.0beta15 [June 18, 2013]
+  Revised libpng.3 so that "doclifter" can process it.
+
+Version 1.7.0beta16 [July 5, 2013]
+  Revised example.c to illustrate use of PNG_DEFAULT_sRGB and PNG_GAMMA_MAC_18
+    as parameters for png_set_gamma().  These have been available since
+    libpng-1.5.4.
+  Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c and revised it
+    to check all compressed chunks known to libpng.
+  Updated documentation to show default behavior of benign errors correctly.
+  Added perfect hash code generation for lists of PNG chunks. This is
+    a work in progress; checked in for use in pngfix.c
+  Ported ARM no-read patch from libpng16.
+  Ported pngfix.c patches from libpng16.
+
+Version 1.7.0beta17 [August 21, 2013]
+  Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
+  Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
+    may be erroneously issued by code-checking applications.
+  Added information about png_set_options() to the manual.
+  Delay calling png_init_filter_functions() until a row with nonzero filter
+    is found.
+
+Version 1.7.0beta18 [September 16, 2013]
+  Fixed inconsistent conditional compilation of png_chunk_unknown_handling()
+    prototype, definition, and usage.  Made it depend on
+    PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere.
+
+Version 1.7.0beta19 [September 30, 2013]
+  Reverted the change to unknown handling #defines; the change breaks 'NOREAD'
+    builds.
+  Fixed default behavior of ARM_NEON_API. If the ARM NEON API option is
+    compiled without the CHECK option it defaulted to on, not off.
+  Catch up with recent libpng16 changes; unknown handling and spelling
+    corrections
+  Avoid up-cast warnings in pngvalid.c. On ARM the alignment requirements of
+    png_modifier are greater than that of png_store and as a consequence
+    compilation of pngvalid.c results in a warning about increased alignment
+    requirements because of the bare cast to (png_modifier*).  The code is
+    safe, because the pointer is known to point to a stack allocated
+    png_modifier, but this change avoids the warning.
+  Fixed some grammatical changes and updated the png chunks list.
+
+Version 1.7.0beta20 [October 13, 2013]
+  Made changes for compatibility with automake 1.14:
+    1) Added the 'compile' program to the list of programs that must be cleaned
+       in autogen.sh
+    2) Added 'subdir-objects' which causes .c files in sub-directories to be
+       compiled such that the corresponding .o files are also in the
+       sub-directory.  This is because automake 1.14 warns that the
+       current behavior of compiling to the top level directory may be removed
+       in the future.
+    3) Updated dependencies on pnglibconf.h to match the new .o locations and
+       added all the files in contrib/libtests and contrib/tools that depend
+       on pnglibconf.h
+    4) Added 'BUILD_SOURCES = pnglibconf.h'; this is the automake recommended
+       way of handling the dependencies of sources that are machine generated;
+       unfortunately it only works if the user does 'make all' or 'make check',
+       so the dependencies (3) are still required.
+  Cleaned up (char*) casts of zlib messages. The latest version of the Intel C
+    compiler complains about casting a string literal as (char*), so copied the
+    treatment of z_const from the library code into pngfix.c
+  Simplified error message code in pngunknown. The simplification has the
+    useful side effect of avoiding a bogus warning generated by the latest
+    version of the Intel C compiler (it objects to
+    condition ? string-literal : string-literal).
+  Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
+    removing the 1.14 'compile' script but never checking for it.
+
+Version 1.7.0beta21 [November 2, 2013]
+  Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
+    arm/filter_neon_intrinsics.c; enable with -mfpu=neon.
+  Revised pngvalid to generate size images with as many filters as it can
+    manage, limited by the number of rows.
+  Cleaned up ARM NEON compilation handling. The tests are now in pngpriv.h
+    and detect the broken GCC compilers.
+  Allow clang derived from older GCC versions to use ARM intrinsics. This
+    causes all clang builds that use -mfpu=neon to use the intrinsics code,
+    not the assembler code.  This has only been tested on iOS 7. It may be
+    necessary to exclude some earlier clang versions but this seems unlikely.
+  Changed NEON implementation selection mechanism. This allows assembler
+    or intrinsics to be turned on at compile time during the build by defining
+    PNG_ARM_NEON_IMPLEMENTATION to the correct value (2 or 1).  This macro
+    is undefined by default and the build type is selected in pngpriv.h.
+
+Version 1.7.0beta22 [November 7, 2013]
+  Fixed #include in filter_neon_intrinsics.c and ctype macros. The ctype char
+    checking macros take an unsigned char argument, not a signed char.
+
+Version 1.7.0beta23 [November 24, 2013]
+  Changed #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED in pngpread.c to
+    #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED to be consistent with
+    what is in pngpriv.h.
+  Moved prototype for png_handle_unknown() in pngpriv.h outside of
+    the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
+  Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
+  Conditionally compile some unused functions reported by -Wall in
+    pngminim.
+  Fixed 'minimal' builds. Various obviously useful minimal configurations
+    don't build because of missing contrib/libtests test programs and
+    overly complex dependencies in scripts/pnglibconf.dfa. This change
+    adds contrib/conftest/*.dfa files that can be used in automatic build
+    scripts to ensure that these configurations continue to build.
+  Enabled WRITE_INVERT and WRITE_PACK in contrib/pngminim/encoder.
+  Fixed pngvalid 'fail' function declaration on the Intel C Compiler.
+    This reverts to the previous 'static' implementation and works round
+    the 'unused static function' warning by using PNG_UNUSED().
+
+Version 1.7.0beta24 [December 15, 2013]
+  Removed or marked PNG_UNUSED some harmless "dead assignments" reported
+    by clang scan-build.
+  Changed tabs to 3 spaces in png_debug macros and changed '"%s"m'
+    to '"%s" m' to improve portability among compilers.
+  Changed png_free_default() to free() in pngtest.c
+  Tidied up pngfix inits and fixed pngtest no-write builds.
+  Bookkeeping: Moved functions around (no changes). Moved transform
+    function definitions before the place where they are called so that
+    they can be masde static. Move the intrapixel functions and the
+    grayscale palette builder out of the png?tran.c files. The latter
+    isn't a transform function and is no longer used internally, and the
+    former MNG specific functions are better placed in pngread/pngwrite.c
+  Made transform implementation functions static. This makes the internal
+    functions called by png_do_{read|write}_transformations static. On an
+    x86-64 DLL build (Gentoo Linux) this reduces the size of the text
+    segment of the DLL by 1208 bytes, about 0.6%. It also simplifies
+    maintenance by removing the declarations from pngpriv.h and allowing
+    easier changes to the internal interfaces.
+  Handle zero-length PLTE chunk or NULL palette with png_error()
+    instead of png_chunk_report(), which by default issues a warning
+    rather than an error, leading to later reading from a NULL pointer
+    (png_ptr->palette) in png_do_expand_palette().
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -3672,7 +3672,8 @@ Version 1.5.6 [November 3, 2011]
   No changes.
 
 Version 1.5.7beta01 [November 4, 2011]
-  Added support for ARM processor (Mans Rullgard)
+  Added support for ARM processor, when decoding all PNG up-filtered rows
+    and any other-filtered rows with 3 or 4 bytes per pixel (Mans Rullgard).
   Fixed bug in pngvalid on early allocation failure; fixed type cast in
     pngmem.c; pngvalid would attempt to call png_error() if the allocation
     of a png_struct or png_info failed. This would probably have led to a
@@ -3827,6 +3828,8 @@ Version 1.6.0beta03 [December 22, 2011]
     so is particularly valuable.  Overall on a 64-bit system the libpng DLL
     decreases in code size by 1733 bytes.  pngerror.o increases in size by
     about 465 bytes because of the new functionality.
+  Added png_convert_to_rfc1123_buffer() and deprecated png_convert_to_rfc1123()
+    to avoid including a spurious buffer in the png_struct.
 
 Version 1.6.0beta04 [December 30, 2011]
   Regenerated configure scripts with automake-1.11.2
@@ -4043,7 +4046,9 @@ Version 1.6.0beta17 [March 10, 2012]
   Deflate/inflate was reworked to move common zlib calls into single
     functions [rw]util.c.  A new shared keyword check routine was also added
     and the 'zbuf' is no longer allocated on progressive read.  It is now
-    possible to call png_inflate() incrementally.
+    possible to call png_inflate() incrementally.  A warning is no longer
+    issued if the language tag or translated keyword in the iTXt chunk
+    has zero length.
   If benign errors are disabled use maximum window on ancilliary inflate.
     This works round a bug introduced in 1.5.4 where compressed ancillary
     chunks could end up with a too-small windowBits value in the deflate
@@ -4098,7 +4103,7 @@ Version 1.6.0beta20 [March 29, 2012]
     iCCP profile over writing the sRGB chunk, controlled by the
     PNG_sRGB_PROFILE_CHECKS option.
   Revised png_set_text_2() to avoid potential memory corruption (fixes
-    CVE-2011-3048).
+    CVE-2011-3048, also known as CVE-2012-3425).
 
 Version 1.6.0beta21 [April 27, 2012]
   Revised scripts/makefile.darwin: use system zlib; remove quotes around
@@ -4134,6 +4139,617 @@ Version 1.6.0beta23 [June 6, 2012]
 Version 1.6.0beta24 [June 7, 2012]
   Don't check palette indexes if num_palette is 0 (as it can be in MNG files).
 
+Version 1.6.0beta25 [June 16, 2012]
+  Revised png_set_keep_unknown_chunks() so num_chunks < 0 means ignore all
+    unknown chunks and all known chunks except for IHDR, PLTE, tRNS, IDAT,
+    and IEND.  Previously it only meant ignore all unknown chunks, the
+    same as num_chunks == 0. Revised png_image_skip_unused_chunks() to
+    provide a list of chunks to be processed instead of a list of chunks to
+    ignore.  Revised contrib/gregbook/readpng2.c accordingly.
+
+Version 1.6.0beta26 [July 10, 2012]
+  Removed scripts/makefile.cegcc from the *.zip and *.7z distributions; it
+    depends on configure, which is not included in those archives.
+  Moved scripts/chkfmt to contrib/tools.
+  Changed "a+w" to "u+w" in Makefile.in to fix CVE-2012-3386.
+
+Version 1.6.0beta27 [August 11, 2012]
+  Do not compile PNG_DEPRECATED, PNG_ALLOC and PNG_PRIVATE when __GNUC__ < 3.
+  Do not use __restrict when GNUC is <= 3.1
+  Removed references to png_zalloc() and png_zfree() from the manual.
+  Fixed configurations where floating point is completely disabled.  Because
+    of the changes to support symbol prefixing PNG_INTERNAL_FUNCTION declares
+    floating point APIs during libpng builds even if they are completely
+    disabled. This requires the png floating point types (png_double*) to be
+    declared even though the functions are never actually defined.  This
+    change provides a dummy definition so that the declarations work, yet any
+    implementation will fail to compile because of an incomplete type.
+  Re-eliminated the use of strcpy() in pngtest.c.  An unncessary use of
+    strcpy() was accidentally re-introduced in libpng16; this change replaces
+    it with strncpy().
+  Eliminated use of png_sizeof(); use sizeof() instead.
+  Use a consistent style for (sizeof type) and (sizeof (array))
+  Cleanup of png_set_filler().  This function does very different things on
+    read and write.  In libpng 1.6 the two cases can be distinguished and
+    considerable code cleanup, and extra error checking, is possible.  This
+    makes calls on the write side that have no effect be ignored with a
+    png_app_error(), which can be disabled in the app using
+    png_set_benign_errors(), and removes the spurious use of usr_channels
+    on the read side.
+  Insist on autotools 1.12.1 for git builds because there are security issues
+    with 1.12 and insisting on anything less would allow 1.12 to be used.
+  Removed info_ptr->signature[8] from WRITE-only builds.
+  Add some conditions for compiling png_fixed().  This is a small function
+    but it requires "-lm" on some platforms.
+  Cause pngtest --strict to fail on any warning from libpng (not just errors)
+    and cause it not to fail at the comparison step if libpng lacks support
+    for writing chunks that it reads from the input (currently only implemented
+    for compressed text chunks).
+  Make all three "make check" test programs work without READ or WRITE support.
+    Now "make check" will succeed even if libpng is compiled with -DPNG_NO_READ
+    or -DPNG_NO_WRITE.  The tests performed are reduced, but the basic reading
+    and writing of a PNG file is always tested by one or more of the tests.
+  Consistently use strlen(), memset(), memcpy(), and memcmp() instead of the
+    png_strlen(), png_memset(), png_memcpy(), and png_memcmp() macros.
+  Removed the png_sizeof(), png_strlen(), png_memset(), png_memcpy(), and
+    png_memcmp() macros.
+  Work around gcc 3.x and Microsoft Visual Studio 2010 complaints. Both object
+    to the split initialization of num_chunks.
+
+Version 1.6.0beta28 [August 29, 2012]
+  Unknown handling fixes and clean up. This adds more correct option
+    control of the unknown handling, corrects the pre-existing bug where
+    the per-chunk 'keep' setting is ignored and makes it possible to skip
+    IDAT chunks in the sequential reader (broken in earlier 1.6 versions).
+    There is a new test program, test-unknown.c, which is a work in progress
+    (not currently part of the test suite).  Comments in the header files now
+    explain how the unknown handling works.
+  Allow fine grain control of unknown chunk APIs. This change allows
+    png_set_keep_unknown_chunks() to be turned off if not required and causes
+    both read and write to behave appropriately (on read this is only possible
+    if the user callback is used to handle unknown chunks).  The change
+    also removes the support for storing unknown chunks in the info_struct
+    if the only unknown handling enabled is via the callback, allowing libpng
+    to be configured with callback reading and none of the unnecessary code.
+  Corrected fix for unknown handling in pngtest. This reinstates the
+    libpng handling of unknown chunks other than vpAg and sTER (including
+    unsafe-to-copy chunks which were dropped before) and eliminates the
+    repositioning of vpAg and sTER in pngtest.png by changing pngtest.png
+    (so the chunks are where libpng would put them).
+  Added "tunknown" test and corrected a logic error in png_handle_unknown()
+    when SAVE support is absent.  Moved the shell test scripts for
+    contrib/libtests from the libpng top directory to contrib/libtests.
+    png_handle_unknown() must always read or skip the chunk, if
+    SAVE_UNKNOWN_CHUNKS is turned off *and* the application does not set
+    a user callback an unknown chunk will not be read, leading to a read
+    error, which was revealed by the "tunknown" test.
+  Cleaned up and corrected ICC profile handling.
+    contrib/libtests/makepng: corrected 'rgb' and 'gray' cases.  profile_error
+    messages could be truncated; made a correct buffer size calculation and
+    adjusted pngerror.c appropriately. png_icc_check_* checking improved;
+    changed the functions to receive the correct color type of the PNG on read
+    or write and check that it matches the color space of the profile (despite
+    what the comments said before, there is danger in assuming the app will
+    cope correctly with an RGB profile on a grayscale image and, since it
+    violates the PNG spec, allowing it is certain to produce inconsistent
+    app behavior and might even cause app crashes.) Check that profiles
+    contain the tags needed to process the PNG (tags all required by the ICC
+    spec). Removed unused PNG_STATIC from pngpriv.h.
+
+Version 1.6.0beta29 [September 4, 2012]
+  Fixed the simplified API example programs to add the *colormap parameter
+    to several of he API and improved the error message if the version field
+    is not set.
+  Added contrib/examples/* to the *.zip and *.7z distributions.
+  Updated simplified API synopses and description of the png_image structure
+    in the manual.
+  Made makepng and pngtest produce identical PNGs, add "--relaxed" option
+    to pngtest. The "--relaxed" option turns off the benign errors that are
+    enabled by default in pre-RC builds. makepng can now write ICC profiles
+    where the length has not been extended to a multiple of 4, and pngtest
+    now intercepts all libpng errors, allowing the previously-introduced
+    "--strict test" on no warnings to actually work.
+  Improved ICC profile handling including cHRM chunk generation and fixed
+    Cygwin+MSVC build errors. The ICC profile handling now includes more
+    checking.  Several errors that caused rejection of the profile are now
+    handled with a warning in such a way that the invalid profiles will be
+    read by default in release (but not pre-RC) builds but will not be
+    written by default.  The easy part of handling the cHRM chunk is written,
+    where the ICC profile contains the required data.  The more difficult
+    part plus guessing a gAMA value requires code to pass selected RGB values
+    through the profile.
+
+Version 1.6.0beta30 [October 24, 2012]
+  Changed ICC profile matrix/vector types to not depend on array type rules.
+    By the ANSI-C standard the new types should be identical to the previous
+    versions, and all known versions of gcc tested with the previous versions
+    except for GCC-4.2.1 work with this version.  The change makes the ANSI-C
+    rule that const applied to an array of elements applies instead to the
+    elements in the array moot by explicitly applying const to the base
+    elements of the png_icc_matrix and png_icc_vector types. The accidental
+    (harmless) 'const' previously applied to the parameters of two of the
+    functions have also been removed.
+  Added a work around for GCC 4.2 optimization bug.
+  Marked the broken (bad white point) original HP sRGB profiles correctly and
+    correct comments.
+  Added -DZ_SOLO to contrib/pngminim/*/makefile to work with zlib-1.2.7
+  Use /MDd for vstudio debug builds. Also added pngunkown to the vstudio
+    builds, fixed build errors and corrected a minor exit code error in
+    pngvalid if the 'touch' file name is invalid.
+  Add updated WARNING file to projects/vstudio from libpng 1.5/vstudio
+  Fixed build when using #define PNG_NO_READ_GAMMA in png_do_compose() in
+    pngrtran.c (Domani Hannes).
+
+Version 1.6.0beta31 [November 1, 2012]
+  Undid the erroneous change to vstudio/pngvalid build in libpng-1.6.0beta30.
+  Made pngvalid so that it will build outside the libpng source tree.
+  Made builds -DPNG_NO_READ_GAMMA compile (the unit tests still fail).
+  Made PNG_NO_READ_GAMMA switch off interfaces that depend on READ_GAMMA.
+    Prior to 1.6.0 switching off READ_GAMMA did unpredictable things to the
+    interfaces that use it (specifically, png_do_background in 1.4 would
+    simply display composite for grayscale images but do composition
+    with the incorrect arithmetic for color ones). In 1.6 the semantic
+    of -DPNG_NO_READ_GAMMA is changed to simply disable any interface that
+    depends on it; this obliges people who set it to consider whether they
+    really want it off if they happen to use any of the interfaces in
+    question (typically most users who disable it won't).
+  Fixed GUIDs in projects/vstudio. Some were duplicated or missing,
+    resulting in VS2010 having to update the files.
+  Removed non-working ICC profile support code that was mostly added to
+    libpng-1.6.0beta29 and beta30. There was too much code for too little
+    gain; implementing full ICC color correction may be desireable but is left
+    up to applications.
+
+Version 1.6.0beta32 [November 25, 2012]
+  Fixed an intermittent SEGV in pngstest due to an uninitialized array element.
+  Added the ability for contrib/libtests/makepng.c to make a PNG with just one
+    color. This is useful for debugging pngstest color inaccuracy reports.
+  Fixed error checking in the simplified write API (Olaf van der Spek)
+  Made png_user_version_check() ok to use with libpng version 1.10.x and later.
+
+Version 1.6.0beta33 [December 10, 2012]
+  Fixed typo in png.c (PNG_SET_CHUNK_MALLOC_MAX should be PNG_CHUNK_MALLOC_MAX)
+    that causes the MALLOC_MAX limit not to work (John Bowler)
+  Change png_warning() to png_app_error() in pngwrite.c and comment the
+    fall-through condition.
+  Change png_warning() to png_app_warning() in png_write_tRNS().
+
+Version 1.7.0alpha01 [December 15, 2012]
+  Started 1.7.0 branch from libpng-1.6.0beta33.
+  Made 8-bit compose and rgb_to_grayscale accuracy improvements.  These
+    changes cause 16-bit arithmetic to be used for 8-bit data in the gamma
+    corrected compose and grayscale operations.  The arithmetic errors have
+    three sources all of which are fixed in this commit:
+    1) 8-bit linear calculations produce massive errors for lower intensity
+       values.
+    2) The old 16-bit "16 to 8" gamma table code erroneously wrote the lowest
+       output value into a table entry which corresponded to multiple output
+       values (so where the value written should have been the closest to the
+       transformed input value.)
+    3) In a number of cases the code to access the 16-bit table did not round;
+       it did a simple shift, which was wrong and made the side effects of (2)
+       even worse.
+  The new gamma code does not have the 16-to-8 problem at the cost of slightly
+    more calculations and the algorithm used to minimize the number of
+    calculations has been extended to all the 16-bit tables; it has advantages
+    for any significant gamma correction.
+  Rearranged png_struct, remove unused members, change png_set_filter handling
+    png_struct members rearranged - partly to reorder to avoid packing, partly
+    to put frequently accessed members at the start and partly to make
+    the grouping more clear. png_set_filter code has been rewritten and the
+    code shared with png_write_start_row moved to a common function.  Comments
+    in png.h have been made more clear. Minor fixes to
+    contrib/libtests/timepng.c and some of the png_*_tRNS logic, including
+    more error detection in png_set_tRNS.
+  Cleaned up USER_LIMITS feature, removing members from png_struct when not
+    required.
+  Rearranged ARM-NEON optimizations to isolate the machine specific code to
+    the hardware subdirectory, and add comments to pngrutil.c so that
+    implementors of other optimizations will know what to do.
+  Fixed cases of unquoted DESTDIR in Makefile.am.
+  Rebuilt Makefile.in, configure, etc., with autoconf-2.69 and automake-1.12.5.
+
+Version 1.7.0alpha02 [December 17, 2012]
+  Removed functions that were deprecated in libpng-1.6.0:
+    png_reset_zstream(), png_info_init_3(), png_data_freer() and its
+    associated flags, png_malloc_default, and png_free_default.
+  Removed some duplicated lines from contrib/tools/scale.c and png.c.
+  Changed some instances of png_warning() to png_app_error().
+  Updated some left over "1.6.0beta32" in code sources.
+  Fixed a "png_structp" prototype (should be png_structrp) in arm_init.c
+  Updated the version-number hack in pngvalid.c
+  
+Version 1.7.0alpha03 [December 19, 2012]
+  Cleaned up and enhanced the configure option; libpng now correctly
+    links and tests against zlib with a prefix; tests have been clarified; and
+    irrelevant or obsolete things (as defined by the autotools man page) have
+    been removed.
+  Documented new PNG_ABORT behavior in the manual and commentary in pngerror.c
+  Cleaned up whitespace in the synopsis portion of the manpage "libpng.3"
+  Fixed previous support for Z_PREFIX in configure builds, corrected sCAL APIs;
+    some of these use floating point arithmetic so they need to be disabled if
+    floating point arithmetic is switched off.  This is a quiet API change -
+    previously it appeared that the APIs were supported if fixed point
+    arithmetic was used internally, however they required certain APIs (floor,
+    modf, frexp, atof) that are part of C floating point support. Changed
+    png_fixed and the gamma code specific version of the same to avoid floor(),
+    which may be a library function (not an intrinsic). Removed unused #if 0
+    code.
+  Disassembled the version number in scripts/options.awk (necessary for
+    building on SunOs).
+
+Version 1.7.0alpha04 [December 23, 2012]
+  Added scripts/makefile.msys contributed by Christopher M. Wheeler
+  Made default Zlib compression settings be configurable. This adds #defines to
+    pnglibconf.h to control the defaults.
+  Fixed Windows build issues, enabled ARM compilation. Various warnings issued
+    by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old
+    GCCs.) ARM support is enabled by default in zlib.props (unsupported by
+    Microsoft) and ARM compilation is made possible by deleting the check for
+    x86. The test programs cannot be run because they are not signed.
+
+Version 1.7.0alpha05 [December 24, 2012]
+  Discontinued distributing libpng-1.x.x.tar.bz2.
+  Discontinued distributing libpng-1.7.0-1.6.0-diff.txt and similar.
+
+Version 1.7.0alpha06 [January 1, 2013]
+  Fixed 'make distcheck' on SUN OS - libpng.so was not being removed
+
+Version 1.7.0alpha07 [January 10, 2013]
+  Fixed conceivable but difficult to repro overflow. Also added two test
+    programs to generate and test a PNG which should have the problem.
+
+Version 1.7.0alpha08 [January 17, 2013]
+  Corrected previous attempt at overflow detection in png_set_unknown_chunks().
+
+Version 1.7.0alpha09 [January 21, 2013]
+  Pulled changes to multi-chunk handling from libpng-1.6.0beta40.
+
+Version 1.7.0alpha10 [February 5, 2013]
+  Make symbol prefixing work with the ARM neon optimizations. Also
+    allow pngpriv.h to be included for preprocessor definitions only, so
+    it can be used in non-C/C++ files.
+  Added png_get_palette_max() function.
+  Changed png_size_t to size_t throughout headers, make sRGB check numbers
+    consistent.
+  Fixed ARM support (Mans Rullgard).
+  Removed stray out-of-order #endif and #ifdef (Mans Rullgard).
+  Ported libpng 1.5 options.awk/dfn file handling to 1.7, fixed one bug.
+  Rebuilt Makefile.in, configure, etc., with autoconf-2.69 and automake-1.13.
+  Minor fixes to assembler changes, verified with a dummy .S file
+  Removed cc -E workround, corrected png_get_palette_max API. Tested on
+    SUN OS cc 5.9, which demonstrates the tokenization problem previously
+    avoided by using /lib/cpp.  Since all .dfn output is now protected
+    in double quotes unless it is to be macro substituted the fix should work
+    everywhere.
+
+Version 1.7.0beta01 [February 15, 2013]
+  Enable parallel tests and rearrange TESTS order to take advantage of
+    the massive speed improvements use a make capable of parallel builds
+    on a multi-CPU machine and pass the right arguments to make (-j10000
+    for GNU make) to get the build to run in parallel.
+  Fixed previous support for Z_PREFIX in configure builds, corrected
+    sCAL APIs; some of these use floating point arithmetic so need to be
+    disabled if floating point arithmetic is switched off.  This is a quiet API
+    change - previously it appeared that the APIs were supported if fixed point
+    arithmetic was used internally, however they required certain APIs (floor,
+    modf, frexp, atof) that are part of C floating point support. Changed
+    png_fixed and the gamma code specific version of the same to avoid floor(),
+    which may be a library function (not an intrinsic). Removed unused #if 0
+    code.
+  Fixed make distcheck to skip over the test result files. They were
+    being included because the whole of the 'tests' directory is included,
+    fixed to just include the actual test files and tests/pngstest.  Also
+    reverted the previous erroneous change to remove the ${srcdir} from the
+    front of contrib, scripts, projects and added an explanation of what is
+    going on to Makefile.am
+  Fixed missing dependency in --prefix builds. The intermediate
+    internal 'prefix.h' file can only be generated correctly after pnglibconf.h,
+    however the dependency was not in Makefile.am.  The symptoms are
+    unpredictable depending on the order make chooses to build pngprefix.h and
+    pnglibconf.h, often the error goes unnoticed because there is a system
+    pnglibconf.h to use instead.
+  Accept "," as a separator in pnglibconf.dfa and allow for
+    continuation lines. This adds to the syntax of "option" and "chunk" lines,
+    allowing the elements to be separated by a "," at the end of an element and
+    interpreting a "," at end of line as a continuation - so the following line
+    is read.  The new syntax is optional and solely provided for readability.
+  Enclosed the new png_get_palette_max in #ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+    block, and revised pnglibconf.h and pnglibconf.h.prebuilt accordingly.
+
+Version 1.7.0beta02 [February 18, 2013]
+  Fixed a race condition in the creation of the build 'scripts' directory
+    while building with a parallel make.
+  Use approved/supported Android method to check for NEON, use Linux/POSIX
+    1003.1 API to check /proc/self/auxv avoiding buffer allocation and other
+    library calls (ported from libpng15).
+  Use parentheses more consistently in "#if defined(MACRO)" tests.
+  Folded long lines.
+
+Version 1.7.0beta03 [February 22, 2013]
+  Reenabled code to allow zero length PLTE chunks for MNG.
+  Fixed ALIGNED_MEMORY support.
+  Allow run-time ARM NEON checking to be disabled. A new configure option:
+    --enable-arm-neon=always will stop the run-time checks. New checks
+    within arm/arm_init.c will cause the code not to be compiled unless
+    __ARM_NEON__ is set. This should make it fail safe (if someone asks
+    for it on then the build will fail if it can't be done.)
+  Updated the INSTALL document.
+
+Version 1.7.0beta04 [February 27, 2013]
+  Revised INSTALL to recommend using CPPFLAGS instead of INCLUDES.
+  Revised scripts/makefile.freebsd to respect ZLIBLIB and ZLIBINC.
+  Revised scripts/dfn.awk to work with the buggy MSYS awk that has trouble
+    with CRLF line endings.
+
+Version 1.7.0beta05 [March 5, 2013]
+  Avoid a possible memory leak in contrib/gregbook/readpng.c
+  Changed user chunk callback API to respect global and per chunk defaults.
+    Previously a return of 0 from a user chunk callback would result in the
+    chunk being saved (if this was safe, even if the chunk was unsafe-to-copy);
+    this change respects the defaults set by the application, so unknown chunks
+    can be discarded by default and known-safe ones preserved.
+  Corrected Android builds and corrected libpng.vers with symbol
+    prefixing. This adds an API to set optimization options externally,
+    providing an alternative and general solution for the non-portable
+    run-time tests used by the ARM Neon code.  It also makes those tests
+    compile and link on Android.  The order of settings vs options in
+    pnglibconf.h is reversed to allow settings to depend on options and
+    options can now set (or override) the defaults for settings.
+
+Version 1.7.0beta06 [March 13, 2013]
+  Corrected simplified API default gamma for color-mapped output, added
+    a flag to change default. In 1.6.0 when the simplified API was used
+    to produce color-mapped output from an input image with no gamma
+    information the gamma assumed for the input could be different from
+    that assumed for non-color-mapped output.  In particular 16-bit depth
+    input files were assumed to be sRGB encoded, whereas in the 'direct'
+    case they were assumed to have linear data.  This was an error.  The
+    fix makes the simplified API treat all input files the same way and
+    adds a new flag to the png_image::flags member to allow the
+    application/user to specify that 16-bit files contain sRGB data
+    rather than the default linear.
+  Fixed bugs in the pngpixel and makepng test programs.
+  Fixed CMakelists.txt to allow building a single variant of the library
+    (Claudio Bley):
+  Introduced a PNG_LIB_TARGETS variable that lists all activated library
+    targets.  It is an error if this variable ends up empty, ie. you have
+    to build at least one library variant.
+  Made the *_COPY targets only depend on library targets actually being build.
+  Use PNG_LIB_TARGETS to unify a code path.
+  Changed the CREATE_SYMLINK macro to expect the full path to a file as the
+    first argument. When symlinking the filename component of that path is
+    determined and used as the link target.
+  Use copy_if_different in the CREATE_SYMLINK macro.
+  Eliminated two warnings from the Intel C compiler. The warnings are
+    technically valid, although a reasonable treatment of division would
+    show it to be incorrect.
+
+Version 1.7.0beta07 [April 14, 2013]
+  Updated documentation of 1.5.x to 1.6.x changes in iCCP chunk handling.
+  Fixed incorrect warning of excess deflate data. End condition - the
+    warning would be produced if the end of the deflate stream wasn't read
+    in the last row.  The warning is harmless.
+  Corrected the test on user transform changes on read. It was in the
+    png_set of the transform function, but that doesn't matter unless the
+    transform function changes the rowbuf size, and that is only valid if
+    transform_info is called.
+  Corrected a misplaced closing bracket in contrib/libtests/pngvalid.c
+    (Flavio Medeiros).
+  Corrected length written to uncompressed iTXt chunks (Samuli Suominen).
+
+Version 1.7.0beta08 [April 18, 2013]
+  Added contrib/tools/fixitxt.c, to repair the erroneous iTXt chunk length
+    written by libpng-1.6.0 and 1.6.1.
+  Disallow storing sRGB information when the sRGB is not supported.
+
+Version 1.7.0beta09 [April 24, 2013]
+  Exposed PNG chunk types in png.h
+  Modified png_uint_32 macros/code to make as few assumptions as possible
+    about the hardware.
+  Revised stack marking in arm/filter_neon.S and configure.ac.
+  Ensure that NEON filter stuff is completely disabled when switched 'off'.
+    Previously the ARM NEON specific files were still built if the option
+    was switched 'off' as opposed to being explicitly disabled.
+
+Version 1.7.0beta10 [April 24, 2013]
+  Attempt to fix the PNG_ARM_NEON configuration mess.
+
+Version 1.7.0beta11 [April 26, 2013]
+  Test for 'arm*', not just 'arm' in the host_cpu configure variable.
+
+Version 1.7.0beta12 [April 30, 2013]
+  Added png_app_warning for out-of-range unknown chunk index in
+    png_set_unknown_chunk_location().
+  Expanded manual paragraph about writing private chunks.
+  Avoid dereferencing NULL pointer possibly returned from
+     png_create_write_struct() (Andrew Church).
+
+Version 1.7.0beta13 [May 12, 2013]
+  Revised contrib/pngminim/*/makefile to generate pnglibconf.h with the
+    right zlib header files.
+  Separated CPPFLAGS and CFLAGS in contrib/pngminim/*/makefile
+  Updated contrib/pngminus/pnm2png.c (Paul Stewart):
+    Check for EOF
+    Ignore "#" delimited comments in input file to pnm2png.c.
+    Fixed whitespace handling
+    Added a call to png_set_packing()
+    Initialize dimension values so if sscanf fails at least we have known
+      invalid values.
+  Calculate our own zlib windowBits when decoding rather than trusting the
+    CMF bytes in the PNG datastream.
+  Added an option to force maximum window size for inflating, which was
+    the behavior of libpng15 and earlier.
+  Added png-fix-itxt and png-fix-too-far-back to the built programs and
+    removed warnings from the source code and timepng that are revealed as
+    a result.
+  Detect wrong libpng versions linked to png-fix-too-far-back, which currently
+    only works with libpng versions that can be made to reliably fail when
+    the deflate data contains an out-of-window reference.  This means only
+    1.6 and later.
+  Attempt to detect configuration issues with png-fix-too-far-back, which
+    requires both the correct libpng and the correct zlib to function
+    correctly.
+  Check ZLIB_VERNUM for mismatches, enclose #error in quotes
+  Added information in the documentation about problems with and fixes for
+    the bad CRC and bad iTXt chunk situations.
+
+Version 1.7.0beta14 [June 8, 2013]
+  Removed a redundant test in png_set_IHDR().
+  Added set(CMAKE_CONFIGURATION_TYPES ...) to CMakeLists.txt (Andrew Hundt)
+  Deleted set(CMAKE_BUILD_TYPE) block from CMakeLists.txt
+  Enclose the prototypes for the simplified write API in #ifdef STDIO/#endif
+  Make ARM NEON support work at compile time (not just configure time).
+    This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when
+    using a compiler that compiles for multiple architectures at one time.
+  Removed PNG_FILTER_OPTIMIZATIONS and PNG_ARM_NEON_SUPPORTED from
+    pnglibconf.h, allowing more of the decisions to be made internally
+    (pngpriv.h) during the compile.  Without this, symbol prefixing is broken
+    under certain circumstances on ARM platforms.  Now only the API parts of
+    the optimizations ('check' vs 'api') are exposed in the public header files
+    except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
+    decision about whether or not to use the optimizations.
+  Protect symbol prefixing against CC/CPPFLAGS/CFLAGS useage.
+    Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
+    on __ARM_NEON__ from configure time to compile time.  This breaks symbol
+    prefixing because the definition of the special png_init_filter_functions
+    call was hidden at configure time if the relevant compiler arguments are
+    passed in CFLAGS as opposed to CC.  This change attempts to avoid all
+    the confusion that would result by declaring the init function even when
+    it is not used, so that it will always get prefixed.
+
+Version 1.7.0beta15 [June 18, 2013]
+  Revised libpng.3 so that "doclifter" can process it.
+
+Version 1.7.0beta16 [July 5, 2013]
+  Revised example.c to illustrate use of PNG_DEFAULT_sRGB and PNG_GAMMA_MAC_18
+    as parameters for png_set_gamma().  These have been available since
+    libpng-1.5.4.
+  Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c and revised it
+    to check all compressed chunks known to libpng.
+  Updated documentation to show default behavior of benign errors correctly.
+  Added perfect hash code generation for lists of PNG chunks. This is
+    a work in progress; checked in for use in pngfix.c
+  Ported ARM no-read patch from libpng16.
+  Ported pngfix.c patches from libpng16.
+
+Version 1.7.0beta17 [August 21, 2013]
+  Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
+  Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
+    may be erroneously issued by code-checking applications.
+  Added information about png_set_options() to the manual.
+  Delay calling png_init_filter_functions() until a row with nonzero filter
+    is found.
+
+Version 1.7.0beta18 [September 16, 2013]
+  Fixed inconsistent conditional compilation of png_chunk_unknown_handling()
+    prototype, definition, and usage.  Made it depend on
+    PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere.
+
+Version 1.7.0beta19 [September 30, 2013]
+  Reverted the change to unknown handling #defines; the change breaks 'NOREAD'
+    builds.
+  Fixed default behavior of ARM_NEON_API. If the ARM NEON API option is
+    compiled without the CHECK option it defaulted to on, not off.
+  Catch up with recent libpng16 changes; unknown handling and spelling
+    corrections
+  Avoid up-cast warnings in pngvalid.c. On ARM the alignment requirements of
+    png_modifier are greater than that of png_store and as a consequence
+    compilation of pngvalid.c results in a warning about increased alignment
+    requirements because of the bare cast to (png_modifier*).  The code is
+    safe, because the pointer is known to point to a stack allocated
+    png_modifier, but this change avoids the warning.
+  Fixed some grammatical changes and updated the png chunks list.
+
+Version 1.7.0beta20 [October 13, 2013]
+  Made changes for compatibility with automake 1.14:
+    1) Added the 'compile' program to the list of programs that must be cleaned
+       in autogen.sh
+    2) Added 'subdir-objects' which causes .c files in sub-directories to be
+       compiled such that the corresponding .o files are also in the
+       sub-directory.  This is because automake 1.14 warns that the
+       current behavior of compiling to the top level directory may be removed
+       in the future.
+    3) Updated dependencies on pnglibconf.h to match the new .o locations and
+       added all the files in contrib/libtests and contrib/tools that depend
+       on pnglibconf.h
+    4) Added 'BUILD_SOURCES = pnglibconf.h'; this is the automake recommended
+       way of handling the dependencies of sources that are machine generated;
+       unfortunately it only works if the user does 'make all' or 'make check',
+       so the dependencies (3) are still required.
+  Cleaned up (char*) casts of zlib messages. The latest version of the Intel C
+    compiler complains about casting a string literal as (char*), so copied the
+    treatment of z_const from the library code into pngfix.c
+  Simplified error message code in pngunknown. The simplification has the
+    useful side effect of avoiding a bogus warning generated by the latest
+    version of the Intel C compiler (it objects to
+    condition ? string-literal : string-literal).
+  Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
+    removing the 1.14 'compile' script but never checking for it.
+
+Version 1.7.0beta21 [November 2, 2013]
+  Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
+    arm/filter_neon_intrinsics.c; enable with -mfpu=neon.
+  Revised pngvalid to generate size images with as many filters as it can
+    manage, limited by the number of rows.
+  Cleaned up ARM NEON compilation handling. The tests are now in pngpriv.h
+    and detect the broken GCC compilers.
+  Allow clang derived from older GCC versions to use ARM intrinsics. This
+    causes all clang builds that use -mfpu=neon to use the intrinsics code,
+    not the assembler code.  This has only been tested on iOS 7. It may be
+    necessary to exclude some earlier clang versions but this seems unlikely.
+  Changed NEON implementation selection mechanism. This allows assembler
+    or intrinsics to be turned on at compile time during the build by defining
+    PNG_ARM_NEON_IMPLEMENTATION to the correct value (2 or 1).  This macro
+    is undefined by default and the build type is selected in pngpriv.h.
+
+Version 1.7.0beta22 [November 7, 2013]
+  Fixed #include in filter_neon_intrinsics.c and ctype macros. The ctype char
+    checking macros take an unsigned char argument, not a signed char.
+
+Version 1.7.0beta23 [November 24, 2013]
+  Changed #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED in pngpread.c to
+    #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED to be consistent with
+    what is in pngpriv.h.
+  Moved prototype for png_handle_unknown() in pngpriv.h outside of
+    the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
+  Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
+  Conditionally compile some unused functions reported by -Wall in
+    pngminim.
+  Fixed 'minimal' builds. Various obviously useful minimal configurations
+    don't build because of missing contrib/libtests test programs and
+    overly complex dependencies in scripts/pnglibconf.dfa. This change
+    adds contrib/conftest/*.dfa files that can be used in automatic build
+    scripts to ensure that these configurations continue to build.
+  Enabled WRITE_INVERT and WRITE_PACK in contrib/pngminim/encoder.
+  Fixed pngvalid 'fail' function declaration on the Intel C Compiler.
+    This reverts to the previous 'static' implementation and works round
+    the 'unused static function' warning by using PNG_UNUSED().
+
+Version 1.7.0beta24 [December 15, 2013]
+  Removed or marked PNG_UNUSED some harmless "dead assignments" reported
+    by clang scan-build.
+  Changed tabs to 3 spaces in png_debug macros and changed '"%s"m'
+    to '"%s" m' to improve portability among compilers.
+  Changed png_free_default() to free() in pngtest.c
+  Tidied up pngfix inits and fixed pngtest no-write builds.
+  Bookkeeping: Moved functions around (no changes). Moved transform
+    function definitions before the place where they are called so that
+    they can be masde static. Move the intrapixel functions and the
+    grayscale palette builder out of the png?tran.c files. The latter
+    isn't a transform function and is no longer used internally, and the
+    former MNG specific functions are better placed in pngread/pngwrite.c
+  Made transform implementation functions static. This makes the internal
+    functions called by png_do_{read|write}_transformations static. On an
+    x86-64 DLL build (Gentoo Linux) this reduces the size of the text
+    segment of the DLL by 1208 bytes, about 0.6%. It also simplifies
+    maintenance by removing the declarations from pngpriv.h and allowing
+    easier changes to the internal interfaces.
+  Handle zero-length PLTE chunk or NULL palette with png_error()
+    instead of png_chunk_report(), which by default issues a warning
+    rather than an error, leading to later reading from a NULL pointer
+    (png_ptr->palette) in png_do_expand_palette().
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CMakeLists.txt

@@ -1,6 +1,6 @@
 # CMakeLists.txt
 
-# Copyright (C) 2007-2011 Glenn Randers-Pehrson
+# Copyright (C) 2007-2013 Glenn Randers-Pehrson
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -9,32 +9,13 @@
 cmake_minimum_required(VERSION 2.4.4)
 set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS true)
 
-if(UNIX AND NOT DEFINED CMAKE_BUILD_TYPE)
-  if(CMAKE_MAJOR_VERSION EQUAL 2 AND CMAKE_MINOR_VERSION EQUAL 4)
-    # workaround CMake 2.4.x bug
-    set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING
-        "Choose the type of build, options are:
-           None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used)
-           Debug
-           Release
-           RelWithDebInfo
-           MinSizeRel.")
-  else()
-    set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING
-        "Choose the type of build, options are:
-           None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used)
-           Debug
-           Release
-           RelWithDebInfo
-           MinSizeRel.")
-  endif()
-endif()
+set(CMAKE_CONFIGURATION_TYPES "Release;Debug;MinSizeRel;RelWithDebInfo")
 
 project(libpng C)
 enable_testing()
 
 set(PNGLIB_MAJOR 1)
-set(PNGLIB_MINOR 6)
+set(PNGLIB_MINOR 7)
 set(PNGLIB_RELEASE 0)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
@@ -139,8 +120,11 @@ endif()
 # NOW BUILD OUR TARGET
 include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIR})
 
+unset(PNG_LIB_TARGETS)
+
 if(PNG_SHARED)
   add_library(${PNG_LIB_NAME} SHARED ${libpng_sources})
+  set(PNG_LIB_TARGETS ${PNG_LIB_NAME})
   if(MSVC)
     # msvc does not append 'lib' - do it here to have consistent name
     set_target_properties(${PNG_LIB_NAME} PROPERTIES PREFIX "lib")
@@ -153,6 +137,7 @@ if(PNG_STATIC)
 # does not work without changing name
   set(PNG_LIB_NAME_STATIC ${PNG_LIB_NAME}_static)
   add_library(${PNG_LIB_NAME_STATIC} STATIC ${libpng_sources})
+  list(APPEND PNG_LIB_TARGETS ${PNG_LIB_NAME_STATIC})
   if(MSVC)
     # msvc does not append 'lib' - do it here to have consistent name
     set_target_properties(${PNG_LIB_NAME_STATIC} PROPERTIES PREFIX "lib")
@@ -160,6 +145,12 @@ if(PNG_STATIC)
   target_link_libraries(${PNG_LIB_NAME_STATIC} ${ZLIB_LIBRARY} ${M_LIBRARY})
 endif()
 
+if(NOT PNG_LIB_TARGETS)
+  message(SEND_ERROR
+    "No library variant selected to build. "
+    "Please enable at least one of the following options: PNG_STATIC, PNG_SHARED")
+endif()
+
 if(PNG_SHARED AND WIN32)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL)
 endif()
@@ -222,14 +213,15 @@ macro(CREATE_SYMLINK SRC_FILE DEST_FILE)
   if(WIN32 AND NOT CYGWIN AND NOT MSYS)
     ADD_CUSTOM_COMMAND(
         OUTPUT ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}   ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
-        COMMAND ${CMAKE_COMMAND} -E copy        ${CMAKE_CURRENT_BINARY_DIR}/${SRC_FILE} ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}
-        COMMAND ${CMAKE_COMMAND} -E copy        ${CMAKE_CURRENT_BINARY_DIR}/${SRC_FILE} ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
-        DEPENDS ${PNG_LIB_NAME} ${PNG_LIB_NAME_STATIC}
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
+        DEPENDS ${PNG_LIB_TARGETS}
         )
     ADD_CUSTOM_TARGET(${DEST_FILE}_COPY ALL DEPENDS ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
   else(WIN32 AND NOT CYGWIN AND NOT MSYS)
-    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${SRC_FILE} ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
-    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${SRC_FILE} ${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+    get_filename_component(LINK_TARGET "${SRC_FILE}" NAME)
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
   endif(WIN32 AND NOT CYGWIN AND NOT MSYS)
 endmacro()
 
@@ -260,9 +252,9 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.0beta24
-    VERSION 16.${PNGLIB_RELEASE}.0
-    SOVERSION 16
+#   VERSION 17.${PNGLIB_RELEASE}.1.7.0beta24
+    VERSION 17.${PNGLIB_RELEASE}.0
+    SOVERSION 17
     CLEAN_DIRECT_OUTPUT 1)
 endif()
 if(PNG_STATIC)
@@ -287,40 +279,33 @@ endif()
 
 # INSTALL
 if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
-  if(PNG_SHARED)
-    install(TARGETS ${PNG_LIB_NAME}
-        ${PNG_EXPORT_RULE}
-        RUNTIME DESTINATION bin
-        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+  install(TARGETS ${PNG_LIB_TARGETS}
+      ${PNG_EXPORT_RULE}
+      RUNTIME DESTINATION bin
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
-    # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin
+  if(PNG_SHARED)
+    # Create a symlink for libpng.dll.a => libpng17.dll.a on Cygwin
     if(CYGWIN OR MINGW)
        get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME} LOCATION_${CMAKE_BUILD_TYPE})
-       get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME)
-       CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_IMPORT_LIBRARY_SUFFIX})
+       CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_IMPORT_LIBRARY_SUFFIX})
        install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}
          DESTINATION ${CMAKE_INSTALL_LIBDIR})
     endif(CYGWIN OR MINGW)
 
     if(NOT WIN32)
       get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME} LOCATION_${CMAKE_BUILD_TYPE})
-      get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME)
-      CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
+      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
       install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
          DESTINATION ${CMAKE_INSTALL_LIBDIR})
     endif(NOT WIN32)
   endif(PNG_SHARED)
 
   if(PNG_STATIC)
-    install(TARGETS ${PNG_LIB_NAME_STATIC}
-        ${PNG_EXPORT_RULE}
-        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
     if(NOT WIN32 OR CYGWIN OR MINGW)
       get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME_STATIC} LOCATION_${CMAKE_BUILD_TYPE})
-      get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME)
-      CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
+      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
       install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
          DESTINATION ${CMAKE_INSTALL_LIBDIR})
     endif(NOT WIN32 OR CYGWIN OR MINGW)

INSTALL

@@ -41,19 +41,33 @@ is not already on your system.  zlib can usually be found
 wherever you got libpng.  zlib can be placed in another directory,
 at the same level as libpng.
 
+If your system already has a preinstalled zlib you will still need
+to have access to the zlib.h and zconf.h include files that
+correspond to the version of zlib that's installed.
+
+If you wish to test with a particular zlib that is not first in the
+standard library search path, put ZLIBLIB, ZLIBINC, CPPFLAGS, LDFLAGS,
+and LD_LIBRARY_PATH in your environment before running "make test"
+or "make distcheck":
+
+ZLIBLIB=/path/to/lib export ZLIBLIB
+ZLIBINC=/path/to/include export ZLIBINC
+CPPFLAGS="-I$ZLIBINC" export CPPFLAGS
+LDFLAGS="-L$ZLIBLIB" export LDFLAGS
+LD_LIBRARY_PATH="$ZLIBLIB:$LD_LIBRARY_PATH" export LD_LIBRARY_PATH
+
+If you are using one of the makefile scripts, put ZLIBLIB and ZLIBINC
+in your environment and type "make ZLIBLIB=$ZLIBLIB ZLIBINC=$ZLIBINC test".
+
 If you want to use "cmake" (see www.cmake.org), type
 
    cmake . -DCMAKE_INSTALL_PREFIX=/path
    make
    make install
 
-If your system already has a preinstalled zlib you will still need
-to have access to the zlib.h and zconf.h include files that
-correspond to the version of zlib that's installed.
-
 You can rename the directories that you downloaded (they
-might be called "libpng-x.y.z" or "libpngNN" and "zlib-1.2.5"
-or "zlib125") so that you have directories called "zlib" and "libpng".
+might be called "libpng-x.y.z" or "libpngNN" and "zlib-1.2.7"
+or "zlib127") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
 
@@ -71,6 +85,7 @@ Your directory structure should look like this:
              depcomp, install-sh, mkinstalldirs, test-pngtest.sh
           contrib
              gregbook
+             libtests
              pngminim
              pngminus
              pngsuite

LICENSE

@@ -10,8 +10,8 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.0beta24, June 7, 2012, are
-Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
+libpng versions 1.2.6, August 15, 2004, through 1.7.0beta24, December 15, 2013, are
+Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
 
@@ -108,4 +108,4 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-June 7, 2012
+December 15, 2013

Makefile.am

@@ -7,19 +7,62 @@ PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
 ACLOCAL_AMFLAGS = -I scripts
 
 # test programs - run on make check, make distcheck
-TESTS_ENVIRONMENT= srcdir=$(srcdir)
-check_PROGRAMS= pngtest
+check_PROGRAMS= pngtest pngunknown pngstest pngvalid
+
+# Utilities - installed
+bin_PROGRAMS= pngfix png-fix-itxt
+
+# This ensures that pnglibconf.h gets built at the start of 'make all' or
+# 'make check', but it does not add dependencies to the individual programs,
+# this is done below.
+#
+# IMPORTANT: always add the object modules of new programs to the list below
+# because otherwise the sequence 'configure; make new-program' will *sometimes*
+# result in the installed (system) pnglibconf.h being used and the result is
+# always wrong and always very confusing.
+BUILT_SOURCES = pnglibconf.h
+
 pngtest_SOURCES = pngtest.c
 pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-TESTS = test-pngtest.sh
 
-# Only do the following if the contrib directory is present.
-check_PROGRAMS+= pngvalid pngstest
 pngvalid_SOURCES = contrib/libtests/pngvalid.c
-pngstest_SOURCES = contrib/libtests/pngstest.c
 pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngstest_SOURCES = contrib/libtests/pngstest.c
 pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-TESTS += test-pngvalid-simple.sh test-pngvalid-full.sh test-pngstest.sh
+
+pngunknown_SOURCES = contrib/libtests/pngunknown.c
+pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngfix_SOURCES = contrib/tools/pngfix.c
+pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
+
+# Generally these are single line shell scripts to run a test with a particular
+# set of parameters:
+TESTS =\
+   tests/pngtest\
+   tests/pngvalid-gamma-16-to-8 tests/pngvalid-gamma-alpha-mode\
+   tests/pngvalid-gamma-background tests/pngvalid-gamma-expand16-alpha-mode\
+   tests/pngvalid-gamma-expand16-background\
+   tests/pngvalid-gamma-expand16-transform tests/pngvalid-gamma-sbit\
+   tests/pngvalid-gamma-threshold tests/pngvalid-gamma-transform\
+   tests/pngvalid-progressive-interlace-size\
+   tests/pngvalid-progressive-interlace-standard\
+   tests/pngvalid-progressive-interlace-transform\
+   tests/pngvalid-progressive-standard tests/pngvalid-standard\
+   tests/pngstest-0g01 tests/pngstest-0g02 tests/pngstest-0g04\
+   tests/pngstest-0g08 tests/pngstest-0g16 tests/pngstest-2c08\
+   tests/pngstest-2c16 tests/pngstest-3p01 tests/pngstest-3p02\
+   tests/pngstest-3p04 tests/pngstest-3p08 tests/pngstest-4a08\
+   tests/pngstest-4a16 tests/pngstest-6a08 tests/pngstest-6a16\
+   tests/pngstest-error tests/pngunknown-IDAT\
+   tests/pngunknown-discard tests/pngunknown-if-safe tests/pngunknown-sAPI\
+   tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg
+
+# These tests are expected, and required, to fail:
+XFAIL_TESTS = tests/pngstest-error
 
 # man pages
 dist_man_MANS= libpng.3 libpngpf.3 png.5
@@ -38,7 +81,8 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c\
 	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa
 
 if PNG_ARM_NEON
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/filter_neon.S
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
+	arm/filter_neon.S arm/filter_neon_intrinsics.c
 endif
 
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
@@ -71,12 +115,14 @@ nodist_pkginclude_HEADERS= pnglibconf.h
 pkgconfigdir = @pkgconfigdir@
 pkgconfig_DATA = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc
 
-#extra source distribution files.
+# Extra source distribution files, '${srcdir}' is used below to stop build files
+# from those directories being included.  This only works if the configure is
+# not done in the source directory!
 EXTRA_DIST= \
 	ANNOUNCE CHANGES INSTALL LICENSE README TODO \
 	pngtest.png pngbar.png pngnow.png pngbar.jpg autogen.sh \
 	${srcdir}/contrib ${srcdir}/projects ${srcdir}/scripts \
-	$(TESTS) \
+	$(TESTS) $(XFAIL_TESTS) tests/pngstest \
 	CMakeLists.txt example.c libpng-manual.txt
 
 SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk scripts/pnglibconf.dfn
@@ -113,6 +159,9 @@ $(PNGLIB_BASENAME)-config: libpng-config
 scripts/sym.out scripts/vers.out: png.h pngconf.h pnglibconf.h
 scripts/prefix.out: png.h pngconf.h pnglibconf.out
 scripts/symbols.out: png.h pngconf.h $(srcdir)/scripts/pnglibconf.h.prebuilt
+scripts/intprefix.out: pnglibconf.h
+
+pnglibconf.out: config.h
 
 libpng.sym: scripts/sym.out
 	rm -f $@
@@ -125,7 +174,7 @@ if DO_PNG_PREFIX
 # Rename functions in scripts/prefix.out with a PNG_PREFIX prefix.
 # Rename macros in scripts/macro.lst from PNG_PREFIXpng_ to PNG_ (the actual
 # implementation of the macro).
-pnglibconf.h: pnglibconf.out scripts/prefix.out scripts/macro.lst
+pnglibconf.h: pnglibconf.out scripts/prefix.out scripts/macro.lst config.h
 	rm -f $@
 	$(AWK) 's==0 && NR>1{print prev}\
 	   s==0{prev=$$0}\
@@ -151,13 +200,27 @@ endif
 $(srcdir)/scripts/pnglibconf.h.prebuilt:
 	@echo "Attempting to build $@" >&2
 	@echo "This is a machine generated file, but if you want to make" >&2
-	@echo "a new one simply make 'scripts/pnglibconf.out' and copy that" >&2
+	@echo "a new one simply make 'scripts/pnglibconf.out', copy that" >&2
+	@echo "AND set PNG_ZLIB_VERNUM to 0 (you MUST do this)" >&2
 	@exit 1
 
 # The following is necessary to ensure that the local pnglibconf.h is used, not
 # an installed one (this can happen immediately after on a clean system if
-# 'make test' is the first thing the user does.)
-contrib/libtests/pngstest.o contrib/libtests/pngvalid.o pngtest.o: pnglibconf.h
+# 'make test' is the first thing the user does.)  Only files which include
+# one of the png source files (typically png.h or pngpriv.h) need to be listed
+# here:
+pngtest.o: pnglibconf.h
+
+contrib/libtests/makepng.o: pnglibconf.h
+contrib/libtests/pngstest.o: pnglibconf.h
+contrib/libtests/pngunknown.o: pnglibconf.h
+contrib/libtests/pngvalid.o: pnglibconf.h
+contrib/libtests/readpng.o: pnglibconf.h
+contrib/libtests/tarith.o: pnglibconf.h
+contrib/libtests/timepng.o: pnglibconf.h
+
+contrib/tools/makesRGB.o: pnglibconf.h
+contrib/tools/pngfix.o: pnglibconf.h
 
 # We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually
 # be built with PNG_USE_READ_MACROS; this prevents the read macros from
@@ -172,16 +235,14 @@ SYMBOL_CFLAGS += -DPNG_PREFIX='@PNG_PREFIX@'
 endif
 
 .dfn.out:
-	rm -f $@ $*.c $*.tf[123]
-	test -d scripts || mkdir scripts
+	rm -f $@ $*.c $*.tf[12]
+	test -d scripts || mkdir scripts || test -d scripts
 	echo '#include "$<"' >$*.c
 	$(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES)\
 	    $(CPPFLAGS) $(SYMBOL_CFLAGS) $*.c > $*.tf1
-	$(SED) -n -e 's|^.*PNG_DEFN_MAGIC *-\(.*\)- *PNG_DEFN_END.*$$|\1|p'\
-	    $*.tf1 >$*.tf2
-	$(SED) -e 's| *PNG_JOIN *||g' -e 's| *$$||' $*.tf2 >$*.tf3
-	rm -f $*.c $*.tf[12]
-	mv $*.tf3 $@
+	$(AWK) -f "${srcdir}/scripts/dfn.awk" out="$*.tf2" $*.tf1 1>&2
+	rm -f $*.c $*.tf1
+	mv $*.tf2 $@
 
 # The .dfn file for pnglibconf.h is machine generated
 pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h pngusr.dfa $(DFA_XTRA)
@@ -230,22 +291,24 @@ dist-hook:
 
 # install the .../include headers as links to the new ones
 install-data-hook:
-	cd $(DESTDIR)$(includedir); rm -f png.h pngconf.h pnglibconf.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/png.h png.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/pngconf.h \
+	cd '$(DESTDIR)$(includedir)'; rm -f png.h pngconf.h pnglibconf.h
+	cd '$(DESTDIR)$(includedir)'; $(LN_S) $(PNGLIB_BASENAME)/png.h png.h
+	cd '$(DESTDIR)$(includedir)'; $(LN_S) $(PNGLIB_BASENAME)/pngconf.h \
 		pngconf.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/pnglibconf.h \
+	cd '$(DESTDIR)$(includedir)'; $(LN_S) $(PNGLIB_BASENAME)/pnglibconf.h \
 		pnglibconf.h
-	cd $(DESTDIR)$(pkgconfigdir); rm -f libpng.pc
-	cd $(DESTDIR)$(pkgconfigdir); $(LN_S) $(PNGLIB_BASENAME).pc libpng.pc
+	cd '$(DESTDIR)$(pkgconfigdir)'; rm -f libpng.pc
+	cd '$(DESTDIR)$(pkgconfigdir)'; $(LN_S) $(PNGLIB_BASENAME).pc libpng.pc
 
 # do evil things to libpng to cause libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ to be used
 install-exec-hook:
-	cd $(DESTDIR)$(bindir); rm -f libpng-config
-	cd $(DESTDIR)$(bindir); $(LN_S) $(PNGLIB_BASENAME)-config libpng-config
+	cd '$(DESTDIR)$(bindir)'; rm -f libpng-config
+	cd '$(DESTDIR)$(bindir)';\
+	   $(LN_S) $(PNGLIB_BASENAME)-config libpng-config
 	@set -x;\
-	cd $(DESTDIR)$(libdir);\
-	for ext in a la so so.@PNGLIB_MAJOR@@PNGLIB_MINOR@.@PNGLIB_RELEASE@ sl dylib dll.a; do\
+	cd '$(DESTDIR)$(libdir)';\
+	for ext in a la so so.@PNGLIB_MAJOR@@PNGLIB_MINOR@.@PNGLIB_RELEASE@\
+	   sl dylib dll.a; do\
 		rm -f libpng.$$ext;\
                 if test -f $(PNGLIB_BASENAME).$$ext; then\
                        $(LN_S) $(PNGLIB_BASENAME).$$ext libpng.$$ext;\
@@ -253,9 +316,18 @@ install-exec-hook:
 	done
 
 uninstall-hook:
-	cd $(DESTDIR)$(includedir); rm -f png.h pngconf.h pnglibconf.h
-	rm -f $(DESTDIR)$(pkgconfigdir)/libpng.pc
-	rm -f $(DESTDIR)$(bindir)/libpng-config
-	rm -f $(DESTDIR)$(libdir)/libpng.a
-	rm -f $(DESTDIR)$(libdir)/libpng.la
-	rm -f $(DESTDIR)$(libdir)/libpng.dll.a
+	cd '$(DESTDIR)$(includedir)'; rm -f png.h pngconf.h pnglibconf.h
+	rm -f '$(DESTDIR)$(pkgconfigdir)/libpng.pc'
+	rm -f '$(DESTDIR)$(bindir)/libpng-config'
+	rm -f '$(DESTDIR)$(libdir)/libpng.a'
+	rm -f '$(DESTDIR)$(libdir)/libpng.la'
+	rm -f '$(DESTDIR)$(libdir)/libpng.so'
+	rm -f '$(DESTDIR)$(libdir)/libpng.so.@PNGLIB_MAJOR@@PNGLIB_MINOR@.@PNGLIB_RELEASE@'
+	rm -f '$(DESTDIR)$(libdir)/libpng.sl'
+	rm -f '$(DESTDIR)$(libdir)/libpng.dylib'
+	rm -f '$(DESTDIR)$(libdir)/libpng.dll.a'
+
+# The following addition ensures that 'make all' always builds the test programs
+# too.  It used to, but some change either in libpng or configure stopped this
+# working.
+all-am: $(check_PROGRAMS)

README

@@ -1,11 +1,11 @@
-README for libpng version 1.6.0beta24 - June 7, 2012 (shared library 16.0)
+README for libpng version 1.7.0beta24 - December 15, 2013 (shared library 17.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
 
-Libpng comes in several distribution formats.  Get libpng-*.tar.gz,
-libpng-*.tar.xz or libpng-*.tar.bz2 if you want UNIX-style line endings
-in the text files, or lpng*.zip if you want DOS-style line endings.
+Libpng comes in several distribution formats.  Get libpng-*.tar.gz or
+libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
+or lpng*.7z or lpng*.zip if you want DOS-style line endings.
 
 Version 0.89 was the first official release of libpng.  Don't let the
 fact that it's the first release fool you.  The libpng library has been in
@@ -77,17 +77,15 @@ compression library that is useful for more things than just PNG files.
 You can use zlib as a drop-in replacement for fread() and fwrite() if
 you are so inclined.
 
-zlib should be available at the same place that libpng is, or at.
-ftp://ftp.info-zip.org/pub/infozip/zlib
+zlib should be available at the same place that libpng is, or at zlib.net.
 
 You may also want a copy of the PNG specification.  It is available
 as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
 these at http://www.libpng.org/pub/png/documents/
 
 This code is currently being archived at libpng.sf.net in the
-[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT)
-at GO GRAPHSUP.  If you can't find it in any of those places,
-e-mail me, and I'll help you find it.
+[DOWNLOAD] area, and at ftp://ftp.simplesystems.org.  If you can't find it
+in any of those places, e-mail me, and I'll help you find it.
 
 If you have any code changes, requests, problems, etc., please e-mail
 them to me.  Also, I'd appreciate any make files or project files,
@@ -123,7 +121,7 @@ and ...".  If in doubt, send questions to me.  I'll bounce them
 to others, if necessary.
 
 Please do not send suggestions on how to change PNG.  We have
-been discussing PNG for sixteen years now, and it is official and
+been discussing PNG for eighteen years now, and it is official and
 finished.  If you have suggestions for libpng, however, I'll
 gladly listen.  Even if your suggestion is not used immediately,
 it may be used later.
@@ -167,23 +165,25 @@ Files in this distribution:
       pngwrite.c    =>  High-level write functions
       pngwtran.c    =>  Write data transformations
       pngwutil.c    =>  Write utility functions
+      arm           =>  Contains optimized code for the ARM platform
       contrib       =>  Contributions
+       examples         =>  Example programs
        gregbook         =>  source code for PNG reading and writing, from
                             Greg Roelofs' "PNG: The Definitive Guide",
                             O'Reilly, 1999
-       msvctest     =>  Builds and runs pngtest using a MSVC workspace
-       pngminus     =>  Simple pnm2png and png2pnm programs
-       pngsuite     =>  Test images
+       libtests         =>  Test programs
+       pngminim         =>  Minimal decoder, encoder, and progressive decoder
+                            programs demonstrating use of pngusr.dfa
+       pngminus         =>  Simple pnm2png and png2pnm programs
+       pngsuite         =>  Test images
+       tools            =>  Various tools
        visupng      =>  Contains a MSVC workspace for VisualPng
       projects      =>  Contains project files and workspaces for
                         building a DLL
-       cbuilder5        =>  Contains a Borland workspace for building
-                            libpng and zlib
-       visualc6         =>  Contains a Microsoft Visual C++ (MSVC)
-                            workspace for building libpng and zlib
+       owatcom          =>  Contains a WATCOM project for building libpng
        visualc71        =>  Contains a Microsoft Visual C++ (MSVC)
                             workspace for building libpng and zlib
-       xcode            =>  Contains an Apple xcode
+       vstudio          =>  Contains a Microsoft Visual C++ (MSVC)
                             workspace for building libpng and zlib
       scripts       =>  Directory containing scripts for building libpng:
                             (see scripts/README.txt for the list of scripts)

arm/arm_init.c

@@ -0,0 +1,232 @@
+
+/* arm_init.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2013 Glenn Randers-Pehrson
+ * Written by Mans Rullgard, 2011.
+ * Last changed in libpng 1.6.6 [September 16, 2013]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are
+ * called.
+ */
+#define _POSIX_SOURCE 1
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+#if PNG_ARM_NEON_OPT > 0
+#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
+#include <signal.h> /* for sig_atomic_t */
+
+#ifdef __ANDROID__
+/* Linux provides access to information about CPU capabilites via
+ * /proc/self/auxv, however Android blocks this while still claiming to be
+ * Linux.  The Andoid NDK, however, provides appropriate support.
+ *
+ * Documentation: http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
+ */
+#include <cpu-features.h>
+
+static int
+png_have_neon(png_structp png_ptr)
+{
+   /* This is a whole lot easier than the mess below, however it is probably
+    * implemented as below, therefore it is better to cache the result (these
+    * function calls may be slow!)
+    */
+   PNG_UNUSED(png_ptr)
+   return android_getCpuFamily() == ANDROID_CPU_FAMILY_ARM &&
+      (android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
+}
+#elif defined(__linux__)
+/* The generic __linux__ implementation requires reading /proc/self/auxv and
+ * looking at each element for one that records NEON capabilities.
+ */
+#include <unistd.h> /* for POSIX 1003.1 */
+#include <errno.h>  /* for EINTR */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <elf.h>
+#include <asm/hwcap.h>
+
+/* A read call may be interrupted, in which case it returns -1 and sets errno to
+ * EINTR if nothing was done, otherwise (if something was done) a partial read
+ * may result.
+ */
+static size_t
+safe_read(png_structp png_ptr, int fd, void *buffer_in, size_t nbytes)
+{
+   size_t ntotal = 0;
+   char *buffer = png_voidcast(char*, buffer_in);
+
+   while (nbytes > 0)
+   {
+      unsigned int nread;
+      int iread;
+
+      /* Passing nread > INT_MAX to read is implementation defined in POSIX
+       * 1003.1, therefore despite the unsigned argument portable code must
+       * limit the value to INT_MAX!
+       */
+      if (nbytes > INT_MAX)
+         nread = INT_MAX;
+
+      else
+         nread = (unsigned int)/*SAFE*/nbytes;
+
+      iread = read(fd, buffer, nread);
+
+      if (iread == -1)
+      {
+         /* This is the devil in the details, a read can terminate early with 0
+          * bytes read because of EINTR, yet it still returns -1 otherwise end
+          * of file cannot be distinguished.
+          */
+         if (errno != EINTR)
+         {
+            png_warning(png_ptr, "/proc read failed");
+            return 0; /* I.e. a permanent failure */
+         }
+      }
+
+      else if (iread < 0)
+      {
+         /* Not a valid 'read' result: */
+         png_warning(png_ptr, "OS /proc read bug");
+         return 0;
+      }
+
+      else if (iread > 0)
+      {
+         /* Continue reading until a permanent failure, or EOF */
+         buffer += iread;
+         nbytes -= (unsigned int)/*SAFE*/iread;
+         ntotal += (unsigned int)/*SAFE*/iread;
+      }
+
+      else
+         return ntotal;
+   }
+
+   return ntotal; /* nbytes == 0 */
+}
+
+static int
+png_have_neon(png_structp png_ptr)
+{
+   int fd = open("/proc/self/auxv", O_RDONLY);
+   Elf32_auxv_t aux;
+
+   /* Failsafe: failure to open means no NEON */
+   if (fd == -1)
+   {
+      png_warning(png_ptr, "/proc/self/auxv open failed");
+      return 0;
+   }
+
+   while (safe_read(png_ptr, fd, &aux, sizeof aux) == sizeof aux)
+   {
+      if (aux.a_type == AT_HWCAP && (aux.a_un.a_val & HWCAP_NEON) != 0)
+      {
+         close(fd);
+         return 1;
+      }
+   }
+
+   close(fd);
+   return 0;
+}
+#else
+   /* We don't know how to do a run-time check on this system */
+#  error "no support for run-time ARM NEON checks"
+#endif /* OS checks */
+#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+
+#ifndef PNG_ALIGNED_MEMORY_SUPPORTED
+#  error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED"
+#endif
+
+void
+png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
+{
+   /* The switch statement is compiled in for ARM_NEON_API, the call to
+    * png_have_neon is compiled in for ARM_NEON_CHECK.  If both are defined
+    * the check is only performed if the API has not set the NEON option on
+    * or off explicitly.  In this case the check controls what happens.
+    *
+    * If the CHECK is not compiled in and the option is UNSET the behavior prior
+    * to 1.6.7 was to use the NEON code - this was a bug caused by having the
+    * wrong order of the 'ON' and 'default' cases.  UNSET now defaults to OFF,
+    * as documented in png.h
+    */
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+   switch ((pp->options >> PNG_ARM_NEON) & 3)
+   {
+      case PNG_OPTION_UNSET:
+         /* Allow the run-time check to execute if it has been enabled -
+          * thus both API and CHECK can be turned on.  If it isn't supported
+          * this case will fall through to the 'default' below, which just
+          * returns.
+          */
+#endif /* PNG_ARM_NEON_API_SUPPORTED */
+#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
+         {
+            static volatile sig_atomic_t no_neon = -1; /* not checked */
+
+            if (no_neon < 0)
+               no_neon = !png_have_neon(pp);
+
+            if (no_neon)
+               return;
+         }
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+         break;
+#endif
+#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+      default: /* OFF or INVALID */
+         return;
+
+      case PNG_OPTION_ON:
+         /* Option turned on */
+         break;
+   }
+#endif
+
+   /* IMPORTANT: any new external functions used here must be declared using
+    * PNG_INTERNAL_FUNCTION in ../pngpriv.h.  This is required so that the
+    * 'prefix' option to configure works:
+    *
+    *    ./configure --with-libpng-prefix=foobar_
+    *
+    * Verify you have got this right by running the above command, doing a build
+    * and examining pngprefix.h; it must contain a #define for every external
+    * function you add.  (Notice that this happens automatically for the
+    * initialization function.)
+    */
+   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
+
+   if (bpp == 3)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+         png_read_filter_row_paeth3_neon;
+   }
+
+   else if (bpp == 4)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+          png_read_filter_row_paeth4_neon;
+   }
+}
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_READ_SUPPORTED */

arm/filter_neon.S

@@ -1,18 +1,36 @@
 
 /* filter_neon.S - NEON optimised filter functions
  *
- * Copyright (c) 2011 Glenn Randers-Pehrson
+ * Copyright (c) 2013 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  */
 
+/* This is required to get the symbol renames, which are #defines, and also
+ * includes the definition (or not) of PNG_ARM_NEON_OPT and
+ * PNG_ARM_NEON_IMPLEMENTATION.
+ */
+#define PNG_VERSION_INFO_ONLY
+#include "../pngpriv.h"
+
 #if defined(__linux__) && defined(__ELF__)
 .section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
 #endif
 
+/* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for
+ * ARM64).  The code in arm/filter_neon_intrinsics.c supports ARM64, however it
+ * only works if -mfpu=neon is specified on the GCC command line.  See pngpriv.h
+ * for the logic which sets PNG_USE_ARM_NEON_ASM:
+ */
+#if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */
+
+#ifdef PNG_READ_SUPPORTED
+#if PNG_ARM_NEON_OPT > 0
+
 #ifdef __ELF__
 #   define ELF
 #else
@@ -223,3 +241,6 @@ func    png_read_filter_row_paeth3_neon, export=1
 
         pop             {r4,pc}
 endfunc
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_READ_SUPPORTED */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */

arm/filter_neon_intrinsics.c

@@ -0,0 +1,372 @@
+
+/* filter_neon_intrinsics.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2013 Glenn Randers-Pehrson
+ * Written by James Yu <james.yu at linaro.org>, October 2013.
+ * Based on filter_neon.S, written by Mans Rullgard, 2011.
+ *
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+/* This code requires -mfpu=neon on the command line: */
+#if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
+
+#include <arm_neon.h>
+
+/* libpng row pointers are not necessarily aligned to any particular boundary,
+ * however this code will only work with appropriate alignment.  arm/arm_init.c
+ * checks for this (and will not compile unless it is done), this code uses
+ * variants of png_aligncast to avoid compiler warnings.
+ */
+#define png_ptr(type,pointer) png_aligncast(type *,pointer)
+#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer)
+
+/* The following relies on a variable 'temp_pointer' being declared with type
+ * 'type'.  This is written this way just to hide the GCC strict aliasing
+ * warning; note that the code is safe because there never is an alias between
+ * the input and output pointers.
+ */
+#define png_ldr(type,pointer)\
+   (temp_pointer = png_ptr(type,pointer), *temp_pointer)
+
+#ifdef PNG_READ_SUPPORTED
+#if PNG_ARM_NEON_OPT > 0
+
+void
+png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint8x16_t qrp, qpp;
+
+      qrp = vld1q_u8(rp);
+      qpp = vld1q_u8(pp);
+      qrp = vaddq_u8(qrp, qpp);
+      vst1q_u8(rp, qrp);
+   }
+}
+
+void
+png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp = vld1q_u8(rp);
+   uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp);
+   uint8x8x2_t vrp = *vrpt;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop;)
+   {
+      uint8x8_t vtmp1, vtmp2;
+      uint32x2_t *temp_pointer;
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vadd_u8(vdest.val[0], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vdest.val[2] = vadd_u8(vdest.val[1], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t, &vtmp);
+      vrp = *vrpt;
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+
+   PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop; rp += 16)
+   {
+      uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      uint8x8x4_t vrp = *vrpt;
+      uint32x2x4_t *temp_pointer;
+
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]);
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+
+   PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t *vrpt;
+   uint8x8x2_t vrp;
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrpt = png_ptr(uint8x8x2_t,&vtmp);
+   vrp = *vrpt;
+
+   for (; rp < rp_stop; pp += 12)
+   {
+      uint8x8_t vtmp1, vtmp2, vtmp3;
+
+      uint8x8x2_t *vppt;
+      uint8x8x2_t vpp;
+
+      uint32x2_t *temp_pointer;
+
+      vtmp = vld1q_u8(pp);
+      vppt = png_ptr(uint8x8x2_t,&vtmp);
+      vpp = *vppt;
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t,&vtmp);
+      vrp = *vrpt;
+
+      vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp3);
+
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint32x2x4_t vtmp;
+      uint8x8x4_t *vrpt, *vppt;
+      uint8x8x4_t vrp, vpp;
+      uint32x2x4_t *temp_pointer;
+
+      vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      vrp = *vrpt;
+      vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+      vppt = png_ptr(uint8x8x4_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+}
+
+static uint8x8_t
+paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c)
+{
+   uint8x8_t d, e;
+   uint16x8_t p1, pa, pb, pc;
+
+   p1 = vaddl_u8(a, b); /* a + b */
+   pc = vaddl_u8(c, c); /* c * 2 */
+   pa = vabdl_u8(b, c); /* pa */
+   pb = vabdl_u8(a, c); /* pb */
+   pc = vabdq_u16(p1, pc); /* pc */
+
+   p1 = vcleq_u16(pa, pb); /* pa <= pb */
+   pa = vcleq_u16(pa, pc); /* pa <= pc */
+   pb = vcleq_u16(pb, pc); /* pb <= pc */
+
+   p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */
+
+   d = vmovn_u16(pb);
+   e = vmovn_u16(p1);
+
+   d = vbsl_u8(d, b, c);
+   e = vbsl_u8(e, a, d);
+
+   return e;
+}
+
+void
+png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t *vrpt;
+   uint8x8x2_t vrp;
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrpt = png_ptr(uint8x8x2_t,&vtmp);
+   vrp = *vrpt;
+
+   for (; rp < rp_stop; pp += 12)
+   {
+      uint8x8x2_t *vppt;
+      uint8x8x2_t vpp;
+      uint8x8_t vtmp1, vtmp2, vtmp3;
+      uint32x2_t *temp_pointer;
+
+      vtmp = vld1q_u8(pp);
+      vppt = png_ptr(uint8x8x2_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t,&vtmp);
+      vrp = *vrpt;
+
+      vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vlast = vtmp2;
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint32x2x4_t vtmp;
+      uint8x8x4_t *vrpt, *vppt;
+      uint8x8x4_t vrp, vpp;
+      uint32x2x4_t *temp_pointer;
+
+      vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      vrp = *vrpt;
+      vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+      vppt = png_ptr(uint8x8x4_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vlast = vpp.val[3];
+
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+}
+
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_READ_SUPPORTED */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */

autogen.sh

@@ -9,15 +9,15 @@
 #
 # For regular ("tarball") distributions all the files should exist.  We do not
 # want them to be updated *under any circumstances*.  It should never be
-# necessary to rune autogen.sh because ./configure --enable-maintainer-mode says
-# what to do if Makeile.am or configure.ac are changed.
+# necessary to run autogen.sh because ./configure --enable-maintainer-mode says
+# what to do if Makefile.am or configure.ac are changed.
 #
 # It is *probably* OK to update the files on a GIT checkout, because they have
 # come from the local tools, but leave that to the user who is assumed to know
 # whether it is ok or required.
 #
 # This script is intended to work without arguments, there are, however, hidden
-# arguments for (a) use while testing the script and (b) to fix up systems that
+# arguments (a) for use while testing the script and (b) to fix up systems that
 # have been broken.  If (b) is required the script prompts for the correct
 # options.  For this reason the options are *NOT* documented in the help; this
 # is deliberate; UTSL.
@@ -74,7 +74,11 @@ done
 #
 # The autotools generated files:
 libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in\
-   config.sub configure depcomp install-sh ltmain.sh missing"
+   config.sub configure depcomp install-sh ltmain.sh missing test-driver"
+#
+# Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
+# versions than those required by configure.ac):
+libpng_autotools_extra="compile"
 #
 # These are separate because 'maintainer-clean' does not remove them.
 libpng_libtool_files="scripts/libtool.m4 scripts/ltoptions.m4\
@@ -94,6 +98,7 @@ libpng_configure_dirs=".deps"
 # of Makefile.  These functions do the two bits of cleaning.
 clean_autotools(){
    rm -rf $libpng_autotools_files $libpng_libtool_files $libpng_autotools_dirs
+   rm -rf $libpng_autotools_extra
 }
 
 clean_configure(){
@@ -198,7 +203,7 @@ case "$mode" in
          echo "  You can run autoreconf yourself if you don't like maintainer"
          echo "  mode and you can also just run autoreconf -f -i to initialize"
          echo "  everything in the first place; this script is only for"
-         echo "  compatiblity with prior releases."
+         echo "  compatibility with prior releases."
          exit 1
       else
          exec >&2
@@ -213,7 +218,7 @@ case "$mode" in
       exec >&2
       echo "Your system has a partial set of autotools generated files."
       echo "autogen.sh is unable to proceed.  The full set of files is"
-      echo "contained in the distribution archive and you do not need to run"
-      echo "autogen.sh if you use it."
+      echo "contained in the libpng 'tar' distribution archive and you do"
+      echo "not need to run autogen.sh if you use it."
       exit 1;;
 esac

configure.ac

@@ -18,17 +18,19 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.0beta24],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.7.0beta24],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
 # color-tests requires automake 1.11 or later
 # silent-rules requires automake 1.11 or later
 # dist-xz requires automake 1.11 or later
-# 1.11.1 fixes a security issue in 1.11
-AM_INIT_AUTOMAKE([1.11.1 foreign dist-xz dist-bzip2 color-tests silent-rules])
-# was:
-# AM_INIT_AUTOMAKE
+# 1.12.2 fixes a security issue in 1.11.2 and 1.12.1
+# 1.13 is required for parallel tests
+AM_INIT_AUTOMAKE([1.13 foreign dist-xz color-tests silent-rules subdir-objects])
+# The following line causes --disable-maintainer-mode to be the default to
+# configure, this is necessary because libpng distributions cannot rely on the
+# time stamps of the autotools generated files being correct
 AM_MAINTAINER_MODE
 
 dnl configure.ac and Makefile.am expect automake 1.11.2 or a compatible later
@@ -37,9 +39,9 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
 
-PNGLIB_VERSION=1.6.0beta24
+PNGLIB_VERSION=1.7.0beta24
 PNGLIB_MAJOR=1
-PNGLIB_MINOR=6
+PNGLIB_MINOR=7
 PNGLIB_RELEASE=0
 
 dnl End of version number stuff
@@ -53,8 +55,7 @@ AC_PROG_CC
 AM_PROG_AS
 LT_PATH_LD
 AC_PROG_CPP
-AC_CHECK_TOOL(SED, sed, :)
-AC_CHECK_TOOL(AWK, awk, :)
+AC_PROG_AWK
 AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
@@ -64,30 +65,23 @@ dnl compatible later version may be used
 LT_INIT([win32-dll])
 LT_PREREQ([2.4.2])
 
-# On Solaris 10 and 12 CPP gets set to cc -E, however this still
-# does some input parsing.  We need strict ANSI-C style tokenization,
-# check this:
-AC_REQUIRE_CPP
-AC_MSG_CHECKING([for a C preprocessor that does not parse its input])
-AC_PREPROC_IFELSE([AC_LANG_SOURCE([[1.1.1 16BIT]])],
-   [DFNCPP="$CPP"],
-   [  DFNCPP=""
-      sav_CPP="$CPP"
-      for CPP in "${CC-cc} -E" "${CC-cc} -E -traditional-cpp" "/lib/cpp" "cpp"
-      do
-         AC_PREPROC_IFELSE([AC_LANG_SOURCE([[1.1.1 16BIT]])],
-            [DFNCPP="$CPP"]
-            [break],,)
-      done
-      CPP="$sav_CPP"
-   ])
-if test -n "$DFNCPP"; then
-   AC_MSG_RESULT([$DFNCPP])
-   AC_SUBST(DFNCPP)
+# Some awks crash when confronted with pnglibconf.dfa, do a test run now
+# to make sure this doesn't happen
+AC_MSG_CHECKING([that AWK works])
+if ${AWK} -f ${srcdir}/scripts/options.awk out="/dev/null" version=search\
+   ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
+   ${srcdir}/pngusr.dfa 1>&2
+then
+   AC_MSG_RESULT([ok])
 else
-   AC_MSG_FAILURE([not found], 1)
+   AC_MSG_FAILURE([failed], 1)
 fi
 
+# This is a remnant of the old cc -E validation, where it may have been
+# necessary to use a different preprocessor for .dfn files
+DFNCPP="$CPP"
+AC_SUBST(DFNCPP)
+
 # -Werror cannot be passed to GCC in CFLAGS because configure will fail (it
 # checks the compiler with a program that generates a warning), add the
 # following option to deal with this
@@ -115,31 +109,138 @@ AC_ARG_ENABLE(werror,
 
 # Checks for header files.
 AC_HEADER_STDC
-AC_CHECK_HEADERS([malloc.h stdlib.h string.h strings.h])
+# Headers used in pngpriv.h:
+AC_CHECK_HEADERS([assert.h stdlib.h string.h float.h fp.h math.h m68881.h])
+# Additional headers used in pngconf.h:
+AC_CHECK_HEADERS([limits.h stddef.h stdio.h setjmp.h time.h])
+# Used by pngread.c (for the simplified API):
+AC_CHECK_HEADERS([errno.h])
+# The following are not required for the standard 'make' build of libpng:
+# Additional requirements of contrib/libtests/makepng.c:
+AC_CHECK_HEADERS([ctype.h])
+# Additional requirements of contrib/libtests/pngvalid.c:
+AC_CHECK_HEADERS([fenv.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
-AC_C_CONST
-AC_TYPE_SIZE_T
-AC_STRUCT_TM
+# Most of these have been removed from 1.7.0 because they checked for non-ANSI-C
+# behaviors and the result were, anyway, not used by earlier versions of libpng.
 AC_C_RESTRICT
 
-# Checks for library functions.
-AC_FUNC_STRTOD
-AC_CHECK_FUNCS([memset], , AC_MSG_ERROR(memset not found in libc))
-AC_CHECK_FUNCS([pow], , AC_CHECK_LIB(m, pow, , AC_MSG_ERROR(cannot find pow)) )
-AC_ARG_WITH(zlib-prefix,
-   AS_HELP_STRING([[[--with-zlib-prefix]]],
-      [prefix that may have been used in installed zlib]),
-      [ZPREFIX=${withval}],
-      [ZPREFIX='z_'])
-AC_CHECK_LIB(z, zlibVersion, ,
-    AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, , AC_MSG_ERROR(zlib not installed)))
+# Checks for library functions; these need to be in order, least demanding to
+# most because the -l directives are added to the head of the list at each
+# check.
+# ANSI-C functions: all are required but they don't have to be implemented in
+# libc, it is perfectly ok to configure with an extra, wrapper, library preset
+# in LIBS.  NOTE: this list may not be complete
+AC_CHECK_FUNCS([memset memcpy strncpy],,
+               AC_MSG_FAILURE([missing ANSI-C functions]))
+
+# floor and ceil are required for FLOATING_POINT, but they can be turned off on
+# the configure command line (and they are independent.)  Default is to 'on'
+AC_ARG_ENABLE([floating-point],[Enable floating point APIs],,
+              [enable_floating_point=yes])
+AC_ARG_ENABLE([fixed-point],[Enable fixed point APIs],,
+              [enable_fixed_point=yes])
+AC_ARG_ENABLE([floating-arithmetic],[Use floating point arithmetic internally],,
+              [enable_floating_arithmetic=yes])
+
+# Check for a requirement for math library support
+if test "$enable_floating_arithmetic" = yes
+then
+   AC_SEARCH_LIBS([floor],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+   AC_SEARCH_LIBS([frexp],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+   AC_SEARCH_LIBS([modf],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+   AC_SEARCH_LIBS([atof],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+   AC_SEARCH_LIBS([pow],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+fi
+
+# Set the relevant defines if required (only if required), this will override
+# anything on the command line.
+if test "$enable_floating_point" != yes
+then
+   AC_MSG_NOTICE([Floating point APIs disabled])
+   AC_DEFINE([PNG_NO_FLOATING_POINT],[1],
+             [No support for floating point APIs])
+fi
+if test "$enable_fixed_point" != yes
+then
+   AC_MSG_NOTICE([Fixed point APIs disabled])
+   AC_DEFINE([PNG_NO_FIXED_POINT],[1],
+             [No support for fixed point APIs])
+fi
+if test "$enable_floating_arithmetic" != yes
+then
+   AC_MSG_NOTICE([Fixed point arithmetic will be used])
+   AC_DEFINE([PNG_NO_FLOATING_ARITHMETIC],[1],
+             [No support for floating point arithmetic])
+fi
 
 # The following is for pngvalid, to ensure it catches FP errors even on
 # platforms that don't enable FP exceptions, the function appears in the math
 # library (typically), it's not an error if it is not found.
-AC_CHECK_LIB([m], [feenableexcept])
-AC_CHECK_FUNCS([feenableexcept])
+AC_SEARCH_LIBS([feenableexcept],[m],AC_DEFINE([HAVE_FEENABLEEXCEPT],[1],
+      [Define to 1 if the feenableexcept function is available]))
+# Required by pngvalid:
+AC_SEARCH_LIBS([ceil],[m])
+
+# zlib checks and arguments;
+#  package zlib: argument is the name of the library
+#  zlib-header: the name of the header file
+#  zlib-prefix: the prefix for library functions, if any
+AC_ARG_WITH([zlib],
+   AS_HELP_STRING([[[--with-zlib=<name>]]],
+                  [base name of the zlib implementation (e.g. 'z')]),,
+   [with_zlib='z'])
+
+z_prefix=
+AC_ARG_WITH([zlib-prefix],
+   AS_HELP_STRING([[[--with-zlib-prefix=<prefix>]]],
+                  [prefix for zlib API functions]),
+   [if test "$withval" = "" -o "$withval" = yes; then
+      with_zlib_prefix='z_'
+      AC_DEFINE([PNG_ZLIB_PREFIX],[z_],[Standard zlib prefix])
+   elif test "${withval}" != "no"; then
+      AC_DEFINE_UNQUOTED([PNG_ZLIB_PREFIX],[${withval}],
+         [User defined zlib prefix])
+   else
+      with_zlib_prefix=
+   fi
+   if test "$with_zlib_prefix" != ""; then
+      AC_DEFINE([Z_PREFIX],[1],[Tell zlib.h to prefix function names])
+      z_prefix="#define Z_PREFIX 1"
+   fi])
+
+AC_ARG_WITH([zlib-header],
+   AS_HELP_STRING([[[--with-zlib-header='<file>' or '"file"']]],
+      [C include argument to locate zlib header file, e.g. <zlib.h>, take
+       care to put single quotes round this on the command line]),
+   [AC_DEFINE_UNQUOTED([PNG_ZLIB_HEADER],[${withval}],[Zlib header file])],
+   with_zlib_header='<zlib.h>')
+
+# AC_CHECK_LIB isn't quite enough for this because we need the special header
+# file too.
+LIBS="-l${with_zlib} $LIBS"
+AC_MSG_CHECKING(
+   [[Library '${with_zlib}' and #include ${with_zlib_header} for symbol '${with_zlib_prefix}zlibVersion']])
+AC_LINK_IFELSE(
+   [AC_LANG_PROGRAM(
+      [[
+${z_prefix}
+#include ${with_zlib_header}
+      ]],
+      [[(void)${with_zlib_prefix}zlibVersion();]])],
+   AC_MSG_RESULT([ok]),
+   AC_MSG_FAILURE([not found]))
 
 AC_MSG_CHECKING([if using Solaris linker])
 SLD=`$LD --version 2>&1 | grep Solaris`
@@ -233,24 +334,59 @@ AC_ARG_WITH(libpng-prefix,
     fi])
 AM_CONDITIONAL([DO_PNG_PREFIX], [test "${with_libpng_prefix:-no}" != "no"])
 
-# Because GCC by default assembles code with an executable stack, even though it
-# compiles C code with a non-executable stack, it is necessary to do a fixup
-# here (this may by GCC specific)
-AC_SUBST([AM_CCASFLAGS], [-Wa,--noexecstack])
+# HOST SPECIFIC OPTIONS
+# =====================
+#
+# ARM
+# ===
+#
+# ARM NEON (SIMD) support.
 
 AC_ARG_ENABLE([arm-neon],
-   AS_HELP_STRING([[[--enable-arm-neon]]], [Enable ARM NEON optimizations]),
-   [if test "${enableval}" = "yes"; then
-      AC_DEFINE([PNG_ARM_NEON], [1], [Enable ARM NEON optimizations])
-      AC_DEFINE([PNG_ALIGNED_MEMORY_SUPPORTED], [1], [Align row buffers])
-    fi])
-AM_CONDITIONAL([PNG_ARM_NEON], [test "${enable_arm_neon:-no}" = yes])
+   AS_HELP_STRING([[[--enable-arm-neon]]],
+      [Enable ARM NEON optimizations: =no/off, check, api, yes/on:]
+      [no/off: disable the optimizations; check: use internal checking code]
+      [(deprecated and poorly supported); api: disable by default, enable by]
+      [a call to png_set_option; yes/on: turn on unconditionally.]
+      [If not specified: determined by the compiler.]),
+   [case "$enableval" in
+      no|off)
+         # disable the default enabling on __ARM_NEON__ systems:
+         AC_DEFINE([PNG_ARM_NEON_OPT], [0],
+                   [Disable ARM Neon optimizations])
+         # Prevent inclusion of the assembler files below:
+         enable_arm_neon=no;;
+      check)
+         AC_DEFINE([PNG_ARM_NEON_CHECK_SUPPORTED], [],
+                   [Check for ARM Neon support at run-time]);;
+      api)
+         AC_DEFINE([PNG_ARM_NEON_API_SUPPORTED], [],
+                   [Turn on ARM Neon optimizations at run-time]);;
+      yes|on)
+         AC_DEFINE([PNG_ARM_NEON_OPT], [2],
+                   [Enable ARM Neon optimizations])
+         AC_MSG_WARN([--enable-arm-neon: please specify 'check' or 'api', if]
+            [you want the optimizations unconditionally pass -mfpu=neon]
+            [to the compiler.]);;
+      *)
+         AC_MSG_ERROR([--enable-arm-neon=${enable_arm_neon}: invalid value])
+   esac])
+
+# Add ARM specific files to all builds where the host_cpu is arm ('arm*') or
+# where ARM optimizations were explicitly requested (this allows a fallback if a
+# future host CPU does not match 'arm*')
+
+AM_CONDITIONAL([PNG_ARM_NEON],
+   [test "$enable_arm_neon" != 'no' &&
+    case "$host_cpu" in
+      arm*) :;;
+      *)    test "$enable_arm_neon" != '';;
+    esac])
 
 AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])
 
 # Config files, substituting as above
-AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in])
-AC_CONFIG_FILES([libpng-config:libpng-config.in],
-   [chmod +x libpng-config])
+AC_CONFIG_FILES([Makefile libpng.pc])
+AC_CONFIG_FILES([libpng-config], [chmod +x libpng-config])
 
 AC_OUTPUT

contrib/conftest/README

@@ -0,0 +1,46 @@
+This directory contains test configuration files, currently always '.dfa' files
+intended to be used in the build by setting the make macro DFA_XTRA to the name
+of the file.
+
+These files are used in release validation of the 'configure' builds of libpng
+by building 'make check', or 'make all-am' for cross-builds, with each .dfa
+file.
+
+The files in this directory may change between minor releases, however
+contributions describing specific builds of libpng are welcomed.  There is no
+guarantee that libpng will continue to build with such configurations; support
+for given configurations can be, and has been, dropped between successive minor
+releases.  However if a .dfa file describing a configuration is not in this
+directory it is very unlikely that it will be tested before a minor release!
+
+You can use these .dfa files as the basis of new configurations.  Files in this
+directory should not have any use restrictions or restrictive licenses.
+
+DOCUMENTATION
+=============
+
+Examples:
+   ${srcdir}/pngusr.dfa
+   ${srcdir}/contrib/pngminim/*/pngusr.dfa
+
+Documentation of the options:
+   ${srcdir}/scripts/pnglibconf.dfa
+
+Documentation of the file format:
+   ${srcdir}/scripts/options.awk
+
+FILE NAMING
+===========
+
+File names in this directory may NOT contain any of the five characters:
+
+   - , + * ?
+
+Neither may they contain any space character.
+
+While other characters may be used it is strongly suggested that file names be
+limited to lower case Latiin alphabetic characters (a-z), digits (0-9) and, if
+necessary the underscore (_) character.  File names should be about 8 characters
+long (excluding the .dfa extension).  Submitted .dfa files should have names
+between 7 and 16 characters long, shorter names (6 characters or less) are
+reserved for standard tests.

contrib/conftest/read.dfa

@@ -0,0 +1,58 @@
+# read.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with basic read support.  This enables the lowest level libpng
+# read API - the one where the calling code has to use a loop to read each row.
+# At present this is the API used by most programs.
+#
+# Support is enabled only for those chunks and transformations that are
+# typically required - others can be added easily.
+#
+
+everything = off
+
+# The sequential read code is enabled here; the progressive code can be used
+# instead but there is no point enabling both.
+
+option SEQUENTIAL_READ on
+
+# Likewise it is pointless enabling both fixed and floating point APIs.  Choose
+# one or the other for both the API and the internal math.
+
+#Fixed point:
+#option FIXED_POINT on
+#option FLOATING_ARITHMETIC off
+
+#Floating point:
+option FLOATING_POINT on
+option FLOATING_ARITHMETIC on
+
+# Basic error handling, IO and user memory support.  The latter allows the
+# application program to provide its own implementations of 'malloc' and 'free'.
+option SETJMP on
+option STDIO on
+option USER_MEM on
+
+# To read the full set of PNG images correctly interlace, transparency and
+# 16-bit support is required.  The application can implement interlace itself,
+# but very few do and it's no longer possible to disable it when READ is
+# enabled.
+option READ_tRNS on
+option READ_16BIT on
+
+# Everything else is application dependent.  This file assumes the app handles
+# all the native PNG bit layouts, so it doesn't need any of layout change
+# transforms, but needs libpng to perform gamma correction.  It doesn't do any
+# colorspace stuff and ignores the 'significant bit' information.
+#
+# If your app always expands the image to a limited set of bit layouts you
+# probably want to consider using the simplified API instead of the low level
+# one - see png.h and s_read.dfa.
+option READ_GAMMA on

contrib/conftest/s_read.dfa

@@ -0,0 +1,35 @@
+# s_read.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with simplified read support (only).  This builds a minimal
+# libpng able to read all PNG formats and convert them into a small number of
+# well understood memory formats.
+#
+
+everything = off
+
+option SIMPLIFIED_READ on
+
+# It isn't necessary to chose fixed or floating point for the APIs because the
+# simplified API doesn't need fixed or floating point numbers.  It is necessary
+# to chose an internal math implementation.  The default (because of 'everything
+# = off') is fixed point - turn the floating point implementation on if you have
+# hardware floating point or prefer your software floating point implementation.
+option FLOATING_ARITHMETIC on
+
+# This is not strictly necessary, but without it the message strings in the API
+# will not be filled in
+option ERROR_TEXT on
+
+# Switching these options on enables the 'AFIRST' and 'BGR' formats - you don't
+# need this if you don't use them, they just allow the in-memory layout to be
+# changed to match common hardware formats.
+option SIMPLIFIED_READ_AFIRST on
+option SIMPLIFIED_READ_BGR on

contrib/conftest/s_write.dfa

@@ -0,0 +1,33 @@
+# s_write.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with (just) simplified write support
+#
+
+everything = off
+
+option SIMPLIFIED_WRITE on
+
+# It isn't necessary to chose fixed or floating point for the APIs because the
+# simplified API doesn't need fixed or floating point numbers.  It is necessary
+# to chose an internal math implementation.  The default (because of 'everything
+# = off') is fixed point - turn the floating point implementation on if you have
+# hardware floating point or prefer your software floating point implementation.
+option FLOATING_ARITHMETIC on
+
+# This is not strictly necessary, but without it the message strings in the API
+# will not be filled in
+option ERROR_TEXT on
+
+# Switching these options on enables the 'AFIRST' and 'BGR' formats - you don't
+# need this if you don't use them, they just allow the in-memory layout to be
+# changed to match common hardware formats.
+option SIMPLIFIED_WRITE_AFIRST on
+option SIMPLIFIED_WRITE_BGR on

contrib/conftest/simple.dfa

@@ -0,0 +1,36 @@
+# simple.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with just the simplified APIs (read and write).
+#
+
+everything = off
+
+option SIMPLIFIED_WRITE on
+option SIMPLIFIED_READ on
+
+# It isn't necessary to chose fixed or floating point for the APIs because the
+# simplified API doesn't need fixed or floating point numbers.  It is necessary
+# to chose an internal math implementation.  The default (because of 'everything
+# = off') is fixed point - turn the floating point implementation on if you have
+# hardware floating point or prefer your software floating point implementation.
+option FLOATING_ARITHMETIC on
+
+# This is not strictly necessary, but without it the message strings in the API
+# will not be filled in
+option ERROR_TEXT on
+
+# Switching these options on enables the 'AFIRST' and 'BGR' formats - you don't
+# need this if you don't use them, they just allow the in-memory layout to be
+# changed to match common hardware formats.
+option SIMPLIFIED_READ_AFIRST on
+option SIMPLIFIED_READ_BGR on
+option SIMPLIFIED_WRITE_AFIRST on
+option SIMPLIFIED_WRITE_BGR on

contrib/conftest/write.dfa

@@ -0,0 +1,45 @@
+# write.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with no read support and minimal write support.
+#
+
+everything = off
+
+# Switch on the write code - this makes a minimalist encoder
+
+option WRITE on
+
+# Choose fixed or floating point APIs and arithmetic.  The choices are
+# independent but normally they will match.  It is typically better to use the
+# floating point if you have floating point hardware.  If you don't know, or
+# (perhaps) to make libpng smaller used fixed point throughout.
+
+#Fixed point:
+#option FIXED_POINT on
+#option FLOATING_ARITHMETIC off
+
+#Floating point:
+option FLOATING_POINT on
+option FLOATING_ARITHMETIC on
+
+# Basic error handling, IO and user memory support.  The latter allows the
+# application program to provide its own implementations of 'malloc' and 'free'.
+option SETJMP on
+option STDIO on
+option USER_MEM on
+
+# Everything else is optional.  Unlike the read code in libpng the write code
+# does not need to deal with arbitrary formats, so only add support for things
+# you really do write!  For example you might only write sRGB images, sometimes
+# with transparency and never write 16 bit images, so:
+option WRITE_sRGB on
+option WRITE_tRNS on
+#option WRITE_16BIT off (this is the default with 'everything = off')

contrib/examples/pngpixel.c

@@ -37,7 +37,7 @@ component(png_const_bytep row, png_uint_32 x, unsigned int c,
     * bytes wide.  Since the row fitted into memory, however, the following must
     * work:
     */
-   png_uint_32 bit_offset_hi = bit_depth * ((x >> 6) * channels + c);
+   png_uint_32 bit_offset_hi = bit_depth * ((x >> 6) * channels);
    png_uint_32 bit_offset_lo = bit_depth * ((x & 0x3f) * channels + c);
 
    row = (png_const_bytep)(((PNG_CONST png_byte (*)[8])row) + bit_offset_hi);
@@ -273,7 +273,7 @@ int main(int argc, const char **argv)
                            ystep = xstep = 1;
                         }
 
-                        /* To find the pixel loop over 'py' for each pass
+                        /* To find the pixel, loop over 'py' for each pass
                          * reading a row and then checking to see if it
                          * contains the pixel.
                          */
@@ -283,12 +283,13 @@ int main(int argc, const char **argv)
 
                            /* png_read_row takes two pointers.  When libpng
                             * handles the interlace the first is filled in
-                            * pixel-by-pixel, the second receives the same
+                            * pixel-by-pixel, and the second receives the same
                             * pixels but they are replicated across the
                             * unwritten pixels so far for each pass.  When we
                             * do the interlace, however, they just contain
                             * the pixels from the interlace pass - giving
-                            * both is wasteful and pointless.
+                            * both is wasteful and pointless, so we pass a
+                            * NULL pointer.
                             */
                            png_read_row(png_ptr, row_tmp, NULL);
 
@@ -326,7 +327,7 @@ int main(int argc, const char **argv)
                else
                {
                   /* Else libpng has raised an error.  An error message has
-                   * already been output, it is only necessary to clean up
+                   * already been output, so it is only necessary to clean up
                    * locally allocated data:
                    */
                   if (row != NULL)

contrib/examples/pngtopng.c

@@ -29,13 +29,17 @@ int main(int argc, const char **argv)
    {
       png_image image;
 
+      /* Only the image structure version number needs to be set. */
       memset(&image, 0, sizeof image);
+      image.version = PNG_IMAGE_VERSION;
 
       if (png_image_begin_read_from_file(&image, argv[1]))
       {
          png_bytep buffer;
 
-         /* Change this to try different formats! */
+         /* Change this to try different formats!  If you set a colormap format
+          * then you must also supply a colormap below.
+          */
          image.format = PNG_FORMAT_RGBA;
 
          buffer = malloc(PNG_IMAGE_SIZE(image));
@@ -43,10 +47,11 @@ int main(int argc, const char **argv)
          if (buffer != NULL)
          {
             if (png_image_finish_read(&image, NULL/*background*/, buffer,
-               0/*row_stride*/))
+               0/*row_stride*/, NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP */))
             {
                if (png_image_write_to_file(&image, argv[2],
-                  0/*convert_to_8bit*/, buffer, 0/*row_stride*/))
+                  0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
+                  NULL/*colormap*/))
                   result = 0;
 
                else

contrib/gregbook/Makefile.sgi

@@ -23,9 +23,9 @@
 
 # macros --------------------------------------------------------------------
 
-PNGINC = -I/usr/local/include/libpng16
-PNGLIB = -L/usr/local/lib -lpng16	  # dynamically linked against libpng
-#PNGLIB = /usr/local/lib/libpng16.a # statically linked against libpng
+PNGINC = -I/usr/local/include/libpng17
+PNGLIB = -L/usr/local/lib -lpng17	  # dynamically linked against libpng
+#PNGLIB = /usr/local/lib/libpng17.a # statically linked against libpng
 # or:
 #PNGINC = -I../..
 #PNGLIB = -L../.. -lpng

contrib/gregbook/Makefile.unx

@@ -26,14 +26,14 @@
 # macros --------------------------------------------------------------------
 
 #PNGDIR = /usr/local/lib
-#PNGINC = -I/usr/local/include/libpng16
-#PNGLIBd = -L$(PNGDIR) -lpng16 # dynamically linked, installed libpng
-#PNGLIBs = $(PNGDIR)/libpng16.a # statically linked, installed libpng
+#PNGINC = -I/usr/local/include/libpng17
+#PNGLIBd = -L$(PNGDIR) -lpng17 # dynamically linked, installed libpng
+#PNGLIBs = $(PNGDIR)/libpng17.a # statically linked, installed libpng
 # or:
 PNGDIR = ../..#	this one is for libpng-x.y.z/contrib/gregbook builds
 #PNGDIR = ../libpng
 PNGINC = -I$(PNGDIR)
-PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng16	# dynamically linked
+PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng17	# dynamically linked
 PNGLIBs = $(PNGDIR)/libpng.a		# statically linked, local libpng
 
 ZDIR = /usr/local/lib

contrib/gregbook/readpng.c

@@ -215,6 +215,10 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
      * libpng function */
 
     if (setjmp(png_jmpbuf(png_ptr))) {
+        free(image_data);
+        image_data = NULL;
+        free(row_pointers);
+        row_pointers = NULL;
         png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
         return NULL;
     }

contrib/gregbook/readpng2.c

@@ -136,29 +136,23 @@ int readpng2_init(mainprog_info *mainprog_ptr)
      * used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT,
      * IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */
     {
-        /* These byte strings were copied from png.h.  If a future libpng
-         * version recognizes more chunks, add them to this list.  If a
-         * future version of readpng2.c recognizes more chunks, delete them
-         * from this list. */
-        static /* const */ png_byte chunks_to_ignore[] = {
-             99,  72,  82,  77, '\0',  /* cHRM */
-            104,  73,  83,  84, '\0',  /* hIST */
-            105,  67,  67,  80, '\0',  /* iCCP */
-            105,  84,  88, 116, '\0',  /* iTXt */
-            111,  70,  70, 115, '\0',  /* oFFs */
-            112,  67,  65,  76, '\0',  /* pCAL */
-            112,  72,  89, 115, '\0',  /* pHYs */
-            115,  66,  73,  84, '\0',  /* sBIT */
-            115,  67,  65,  76, '\0',  /* sCAL */
-            115,  80,  76,  84, '\0',  /* sPLT */
-            115,  84,  69,  82, '\0',  /* sTER */
-            116,  69,  88, 116, '\0',  /* tEXt */
-            116,  73,  77,  69, '\0',  /* tIME */
-            122,  84,  88, 116, '\0'   /* zTXt */
-        };
+        /* These byte strings were copied from png.h.  If a future version
+         * of readpng2.c recognizes more chunks, add them to this list.
+         */
+        static PNG_CONST png_byte chunks_to_process[] = {
+            98,  75,  71,  68, '\0',  /* bKGD */
+           103,  65,  77,  65, '\0',  /* gAMA */
+           115,  82,  71,  66, '\0',  /* sRGB */
+           };
 
-        png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
-          chunks_to_ignore, sizeof(chunks_to_ignore)/5);
+       /* Ignore all chunks except for IHDR, PLTE, tRNS, IDAT, and IEND */
+       png_set_keep_unknown_chunks(png_ptr, -1 /* PNG_HANDLE_CHUNK_NEVER */,
+          NULL, -1);
+
+       /* But do not ignore chunks in the "chunks_to_process" list */
+       png_set_keep_unknown_chunks(png_ptr,
+          0 /* PNG_HANDLE_CHUNK_AS_DEFAULT */, chunks_to_process,
+          sizeof(chunks_to_process)/5);
     }
 #endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
 

contrib/libtests/fakepng.c

@@ -0,0 +1,57 @@
+/* Fake a PNG - just write it out directly. */
+#include <stdio.h>
+#include <zlib.h> /* for crc32 */
+
+void
+put_uLong(uLong val)
+{
+   putchar(val >> 24);
+   putchar(val >> 16);
+   putchar(val >>  8);
+   putchar(val >>  0);
+}
+
+void
+put_chunk(const unsigned char *chunk, uInt length)
+{
+   uLong crc;
+
+   put_uLong(length-4); /* Exclude the tag */
+
+   fwrite(chunk, length, 1, stdout);
+
+   crc = crc32(0, Z_NULL, 0);
+   put_uLong(crc32(crc, chunk, length));
+}
+
+const unsigned char signature[] =
+{
+   137, 80, 78, 71, 13, 10, 26, 10
+};
+
+const unsigned char IHDR[] =
+{
+   73, 72, 68, 82, /* IHDR */
+   0, 0, 0, 1, /* width */
+   0, 0, 0, 1, /* height */
+   1, /* bit depth */
+   0, /* color type: greyscale */
+   0, /* compression method */
+   0, /* filter method */
+   0  /* interlace method: none */
+};
+
+const unsigned char unknown[] =
+{
+   'u', 'n', 'K', 'n' /* "unKn" - private safe to copy */
+};
+
+int
+main(void)
+{
+   fwrite(signature, sizeof signature, 1, stdout);
+   put_chunk(IHDR, sizeof IHDR);
+
+   for(;;)
+      put_chunk(unknown, sizeof unknown);
+}

contrib/libtests/makepng.c

@@ -10,7 +10,8 @@
  *
  * Make a test PNG image.  The arguments are as follows:
  *
- *  makepng [--sRGB|--linear|--1.8] color-type bit-depth [file-name]
+ *  makepng [--sRGB|--linear|--1.8] [--color=<color>] color-type bit-depth \
+ *      [file-name]
  *
  * The color-type may be numeric (and must match the numbers used by the PNG
  * specification) or one of the format names listed below.  The bit-depth is the
@@ -23,7 +24,8 @@
  * approximately value^(1/1.45) to the color values and so a gAMA chunk of 65909
  * is written (1.45/2.2).
  *
- * The image data is generated internally.  The images used are as follows:
+ * The image data is generated internally.  Unless --color is given the images
+ * used are as follows:
  *
  * 1 channel: a square image with a diamond, the least luminous colors are on
  *    the edge of the image, the most luminous in the center.
@@ -58,9 +60,14 @@
  * 16 bits:           256x256
  * More than 16 bits: 1024x1024
  *
- * Row filtering is turned off (the 'none' filter is used on every row) and  the
+ * Row filtering is turned off (the 'none' filter is used on every row) and the
  * images are not interlaced.
  *
+ * If --color is given then the whole image has that color, color-mapped images
+ * will have exactly one palette entry and all image files with be 16x16 in
+ * size.  The color value is 1 to 4 decimal numbers as appropriate for the color
+ * type.
+ *
  * If file-name is given then the PNG is written to that file, else it is
  * written to stdout.  Notice that stdout is not supported on systems where, by
  * default, it assumes text output; this program makes no attempt to change the
@@ -72,10 +79,11 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <ctype.h>
 #include <math.h>
 #include <errno.h>
 
-#if (defined HAVE_CONFIG_H) && !(defined PNG_NO_CONFIG_H)
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
 #  include <config.h>
 #endif
 
@@ -127,18 +135,24 @@ pixel_depth_of_type(int color_type, int bit_depth)
 }
 
 static unsigned int
-image_size_of_type(int color_type, int bit_depth)
+image_size_of_type(int color_type, int bit_depth, unsigned int *colors)
 {
-   int pixel_depth = pixel_depth_of_type(color_type, bit_depth);
-
-   if (pixel_depth < 8)
-      return 64;
-
-   else if (pixel_depth > 16)
-      return 1024;
+   if (*colors)
+      return 16;
 
    else
-      return 256;
+   {
+      int pixel_depth = pixel_depth_of_type(color_type, bit_depth);
+
+      if (pixel_depth < 8)
+         return 64;
+
+      else if (pixel_depth > 16)
+         return 1024;
+
+      else
+         return 256;
+   }
 }
 
 static void
@@ -154,7 +168,7 @@ set_color(png_colorp color, png_bytep trans, unsigned int red,
 
 static int
 generate_palette(png_colorp palette, png_bytep trans, int bit_depth,
-   png_const_bytep gamma_table)
+   png_const_bytep gamma_table, unsigned int *colors)
 {
    /*
     * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white
@@ -165,39 +179,69 @@ generate_palette(png_colorp palette, png_bytep trans, int bit_depth,
     * 4-bit: the 16 combinations of the 2-bit case
     * 8-bit: the 256 combinations of the 4-bit case
     */
-   if (bit_depth == 1)
+   switch (colors[0])
    {
-      set_color(palette+0, trans+0, 255, 0, 0, 0, gamma_table);
-      set_color(palette+1, trans+1, 255, 255, 255, 255, gamma_table);
-      return 2;
-   }
+      default:
+         fprintf(stderr, "makepng: --colors=...: invalid count %u\n",
+            colors[0]);
+         exit(1);
 
-   else
-   {
-      unsigned int size = 1U << (bit_depth/2); /* 2, 4 or 16 */
-      unsigned int x, y, ip;
-
-      for (x=0; x<size; ++x) for (y=0; y<size; ++y)
-      {
-         ip = x + (size * y);
-
-         /* size is at most 16, so the scaled value below fits in 16 bits */
-#        define interp(pos, c1, c2) ((pos * c1) + ((size-pos) * c2))
-#        define xyinterp(x, y, c1, c2, c3, c4) (((size * size / 2) +\
-            (interp(x, c1, c2) * y + (size-y) * interp(x, c3, c4))) /\
-            (size*size))
-
-         set_color(palette+ip, trans+ip,
-            /* color:    green, red,blue,white */
-            xyinterp(x, y,   0, 255,   0, 255),
-            xyinterp(x, y, 255,   0,   0, 255),
-            xyinterp(x, y,   0,   0, 255, 255),
-            /* alpha:        0, 102, 204, 255) */
-            xyinterp(x, y,   0, 102, 204, 255),
+      case 1:
+         set_color(palette+0, trans+0, colors[1], colors[1], colors[1], 255,
             gamma_table);
-      }
+         return 1;
 
-      return ip+1;
+      case 2:
+         set_color(palette+0, trans+0, colors[1], colors[1], colors[1],
+            colors[2], gamma_table);
+         return 1;
+
+      case 3:
+         set_color(palette+0, trans+0, colors[1], colors[2], colors[3], 255,
+            gamma_table);
+         return 1;
+
+      case 4:
+         set_color(palette+0, trans+0, colors[1], colors[2], colors[3],
+            colors[4], gamma_table);
+         return 1;
+
+      case 0:
+         if (bit_depth == 1)
+         {
+            set_color(palette+0, trans+0, 255, 0, 0, 0, gamma_table);
+            set_color(palette+1, trans+1, 255, 255, 255, 255, gamma_table);
+            return 2;
+         }
+
+         else
+         {
+            unsigned int size = 1U << (bit_depth/2); /* 2, 4 or 16 */
+            unsigned int x, y, ip;
+
+            for (x=0; x<size; ++x) for (y=0; y<size; ++y)
+            {
+               ip = x + (size * y);
+
+               /* size is at most 16, so the scaled value below fits in 16 bits
+                */
+#              define interp(pos, c1, c2) ((pos * c1) + ((size-pos) * c2))
+#              define xyinterp(x, y, c1, c2, c3, c4) (((size * size / 2) +\
+                  (interp(x, c1, c2) * y + (size-y) * interp(x, c3, c4))) /\
+                  (size*size))
+
+               set_color(palette+ip, trans+ip,
+                  /* color:    green, red,blue,white */
+                  xyinterp(x, y,   0, 255,   0, 255),
+                  xyinterp(x, y, 255,   0,   0, 255),
+                  xyinterp(x, y,   0,   0, 255, 255),
+                  /* alpha:        0, 102, 204, 255) */
+                  xyinterp(x, y,   0, 102, 204, 255),
+                  gamma_table);
+            }
+
+            return ip+1;
+         }
    }
 }
 
@@ -207,7 +251,7 @@ set_value(png_bytep row, size_t rowbytes, png_uint_32 x, unsigned int bit_depth,
 {
    unsigned int mask = (1U << bit_depth)-1;
 
-   x *= bit_depth;  /* Maxium x is 4*1024, maxium bit_depth is 16 */
+   x *= bit_depth;  /* Maximum x is 4*1024, maximum bit_depth is 16 */
 
    if (value <= mask)
    {
@@ -264,12 +308,13 @@ set_value(png_bytep row, size_t rowbytes, png_uint_32 x, unsigned int bit_depth,
 
 static void
 generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
-   int bit_depth, png_const_bytep gamma_table, double conv)
+   int bit_depth, png_const_bytep gamma_table, double conv,
+   unsigned int *colors)
 {
-   png_uint_32 size_max = image_size_of_type(color_type, bit_depth)-1;
+   png_uint_32 size_max = image_size_of_type(color_type, bit_depth, colors)-1;
    png_uint_32 depth_max = (1U << bit_depth)-1; /* up to 65536 */
 
-   switch (channels_of_type(color_type))
+   if (colors[0] == 0) switch (channels_of_type(color_type))
    {
    /* 1 channel: a square image with a diamond, the least luminous colors are on
     *    the edge of the image, the most luminous in the center.
@@ -389,13 +434,130 @@ generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
          fprintf(stderr, "makepng: internal bad channel count\n");
          exit(2);
    }
+
+   else if (color_type & PNG_COLOR_MASK_PALETTE)
+   {
+      /* Palette with fixed color: the image rows are all 0 and the image width
+       * is 16.
+       */
+      memset(row, 0, rowbytes);
+   }
+
+   else if (colors[0] == channels_of_type(color_type))
+      switch (channels_of_type(color_type))
+      {
+         case 1:
+            {
+               const png_uint_32 luma = colors[1];
+               png_uint_32 x;
+
+               for (x=0; x<=size_max; ++x)
+                  set_value(row, rowbytes, x, bit_depth, luma, gamma_table,
+                     conv);
+            }
+            break;
+
+         case 2:
+            {
+               const png_uint_32 luma = colors[1];
+               const png_uint_32 alpha = colors[2];
+               png_uint_32 x;
+
+               for (x=0; x<size_max; ++x)
+               {
+                  set_value(row, rowbytes, 2*x, bit_depth, luma, gamma_table,
+                     conv);
+                  set_value(row, rowbytes, 2*x+1, bit_depth, alpha, gamma_table,
+                     conv);
+               }
+            }
+            break;
+
+         case 3:
+            {
+               const png_uint_32 red = colors[1];
+               const png_uint_32 green = colors[2];
+               const png_uint_32 blue = colors[3];
+               png_uint_32 x;
+
+               for (x=0; x<=size_max; ++x)
+               {
+                  set_value(row, rowbytes, 3*x+0, bit_depth, red, gamma_table,
+                     conv);
+                  set_value(row, rowbytes, 3*x+1, bit_depth, green, gamma_table,
+                     conv);
+                  set_value(row, rowbytes, 3*x+2, bit_depth, blue, gamma_table,
+                     conv);
+               }
+            }
+            break;
+
+         case 4:
+            {
+               const png_uint_32 red = colors[1];
+               const png_uint_32 green = colors[2];
+               const png_uint_32 blue = colors[3];
+               const png_uint_32 alpha = colors[4];
+               png_uint_32 x;
+
+               for (x=0; x<=size_max; ++x)
+               {
+                  set_value(row, rowbytes, 4*x+0, bit_depth, red, gamma_table,
+                     conv);
+                  set_value(row, rowbytes, 4*x+1, bit_depth, green, gamma_table,
+                     conv);
+                  set_value(row, rowbytes, 4*x+2, bit_depth, blue, gamma_table,
+                     conv);
+                  set_value(row, rowbytes, 4*x+3, bit_depth, alpha, gamma_table,
+                     conv);
+               }
+            }
+         break;
+
+         default:
+            fprintf(stderr, "makepng: internal bad channel count\n");
+            exit(2);
+      }
+
+   else
+   {
+      fprintf(stderr,
+         "makepng: --color: count(%u) does not match channels(%u)\n",
+         colors[0], channels_of_type(color_type));
+      exit(1);
+   }
+}
+
+
+static void PNGCBAPI
+makepng_warning(png_structp png_ptr, png_const_charp message)
+{
+   const char **ep = png_get_error_ptr(png_ptr);
+   const char *name;
+
+   if (ep != NULL && *ep != NULL)
+      name = *ep;
+
+   else
+      name = "makepng";
+
+  fprintf(stderr, "%s: warning: %s\n", name, message);
+}
+
+static void PNGCBAPI
+makepng_error(png_structp png_ptr, png_const_charp message)
+{
+   makepng_warning(png_ptr, message);
+   png_longjmp(png_ptr, 1);
 }
 
 static int /* 0 on success, else an error code */
-write_png(FILE *fp, int color_type, int bit_depth,
-   volatile png_fixed_point gamma, chunk_insert * volatile insert)
+write_png(const char **name, FILE *fp, int color_type, int bit_depth,
+   volatile png_fixed_point gamma, chunk_insert * volatile insert,
+   unsigned int filters, unsigned int *colors)
 {
-   png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+   png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+      name, makepng_error, makepng_warning);
    volatile png_infop info_ptr = NULL;
    volatile png_bytep row = NULL;
 
@@ -426,7 +588,7 @@ write_png(FILE *fp, int color_type, int bit_depth,
       png_error(png_ptr, "OOM allocating info structure");
 
    {
-      unsigned int size = image_size_of_type(color_type, bit_depth);
+      unsigned int size = image_size_of_type(color_type, bit_depth, colors);
       png_fixed_point real_gamma = 45455; /* For sRGB */
       png_byte gamma_table[256];
       double conv;
@@ -462,8 +624,8 @@ write_png(FILE *fp, int color_type, int bit_depth,
 
             gamma_table[0] = 0;
 
-            for (i=0; i<255; ++i)
-               gamma_table[i] = (png_byte)floor(pow(i/255.,conv) * 255 + 127.5);
+            for (i=1; i<255; ++i)
+               gamma_table[i] = (png_byte)floor(pow(i/255.,conv) * 255 + .5);
 
             gamma_table[255] = 255;
          }
@@ -478,7 +640,8 @@ write_png(FILE *fp, int color_type, int bit_depth,
          png_color palette[256];
          png_byte trans[256];
 
-         npalette = generate_palette(palette, trans, bit_depth, gamma_table);
+         npalette = generate_palette(palette, trans, bit_depth, gamma_table,
+            colors);
          png_set_PLTE(png_ptr, info_ptr, palette, npalette);
          png_set_tRNS(png_ptr, info_ptr, trans, npalette-1,
             NULL/*transparent color*/);
@@ -516,7 +679,7 @@ write_png(FILE *fp, int color_type, int bit_depth,
       png_write_info(png_ptr, info_ptr);
 
       /* Restrict the filters */
-      png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);
+      png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, filters);
 
       {
          int passes = png_set_interlace_handling(png_ptr);
@@ -535,7 +698,7 @@ write_png(FILE *fp, int color_type, int bit_depth,
             for (y=0; y<size; ++y)
             {
                generate_row(row, rowbytes, y, color_type, bit_depth,
-                  gamma_table, conv);
+                  gamma_table, conv, colors);
                png_write_row(png_ptr, row);
             }
          }
@@ -603,7 +766,10 @@ load_file(png_const_charp name, png_bytepp result)
 
                if (total > 0)
                {
-                  png_bytep data = malloc(total);
+                  /* Round up to a multiple of 4 here to allow an iCCP profile
+                   * to be padded to a 4x boundary.
+                   */
+                  png_bytep data = malloc((total+3)&~3);
 
                   if (data != NULL)
                   {
@@ -728,12 +894,13 @@ insert_iCCP(png_structp png_ptr, png_infop info_ptr, int nparams,
       case '<':
          {
             png_size_t filelen = load_file(params[1]+1, &profile);
-            if (filelen > 0xffffffff) /* Maximum profile length */
+            if (filelen > 0xfffffffc) /* Maximum profile length */
             {
                fprintf(stderr, "%s: file too long (%lu) for an ICC profile\n",
                   params[1]+1, (unsigned long)filelen);
                exit(1);
             }
+
             proflen = (png_uint_32)filelen;
          }
          break;
@@ -770,9 +937,14 @@ insert_iCCP(png_structp png_ptr, png_infop info_ptr, int nparams,
    if (proflen & 3)
    {
       fprintf(stderr,
-         "--insert iCCP %s: profile length must be a multiple of 4\n",
+         "makepng: --insert iCCP %s: profile length made a multiple of 4\n",
          params[1]);
-      result = 0; /* Cannot fix this! */
+
+      /* load_file allocates extra space for this padding, the ICC spec requires
+       * padding with zero bytes.
+       */
+      while (proflen & 3)
+         profile[proflen++] = 0;
    }
 
    if (profile != NULL && proflen > 3)
@@ -1059,6 +1231,48 @@ find_insert(png_const_charp what, png_charp param)
    return NULL;
 }
 
+/* This is a not-very-good parser for a sequence of numbers (including 0).  It
+ * doesn't accept some apparently valid things, but it accepts all the sensible
+ * combinations.
+ */
+static void
+parse_color(char *arg, unsigned int *colors)
+{
+   unsigned int ncolors = 0;
+
+   while (*arg && ncolors < 4)
+   {
+      char *ep = arg;
+
+      unsigned long ul = strtoul(arg, &ep, 0);
+
+      if (ul > 65535)
+      {
+         fprintf(stderr, "makepng --color=...'%s': too big\n", arg);
+         exit(1);
+      }
+
+      if (ep == arg)
+      {
+         fprintf(stderr, "makepng --color=...'%s': not a valid color\n", arg);
+         exit(1);
+      }
+
+      if (*ep) ++ep; /* skip a separator */
+      arg = ep;
+
+      colors[++ncolors] = (unsigned int)ul; /* checked above */
+   }
+
+   if (*arg)
+   {
+      fprintf(stderr, "makepng --color=...'%s': too many values\n", arg);
+      exit(1);
+   }
+
+   *colors = ncolors;
+}
+
 int
 main(int argc, char **argv)
 {
@@ -1066,13 +1280,17 @@ main(int argc, char **argv)
    const char *file_name = NULL;
    int color_type = 8; /* invalid */
    int bit_depth = 32; /* invalid */
+   unsigned int colors[5];
+   unsigned int filters = PNG_ALL_FILTERS;
    png_fixed_point gamma = 0; /* not set */
    chunk_insert *head_insert = NULL;
    chunk_insert **insert_ptr = &head_insert;
 
+   memset(colors, 0, sizeof colors);
+
    while (--argc > 0)
    {
-      const char *arg = *++argv;
+      char *arg = *++argv;
 
       if (strcmp(arg, "--sRGB") == 0)
       {
@@ -1092,6 +1310,18 @@ main(int argc, char **argv)
          continue;
       }
 
+      if (strcmp(arg, "--nofilters") == 0)
+      {
+         filters = PNG_FILTER_NONE;
+         continue;
+      }
+
+      if (strncmp(arg, "--color=", 8) == 0)
+      {
+          parse_color(arg+8, colors);
+          continue;
+      }
+
       if (argc >= 3 && strcmp(arg, "--insert") == 0)
       {
          png_const_charp what = *++argv;
@@ -1125,7 +1355,7 @@ main(int argc, char **argv)
 
       if (strncmp(arg, "gray", 4) == 0)
       {
-         if (arg[5] == 0)
+         if (arg[4] == 0)
          {
             color_type = PNG_COLOR_TYPE_GRAY;
             continue;
@@ -1142,7 +1372,7 @@ main(int argc, char **argv)
 
       if (strncmp(arg, "rgb", 3) == 0)
       {
-         if (arg[4] == 0)
+         if (arg[3] == 0)
          {
             color_type = PNG_COLOR_TYPE_RGB;
             continue;
@@ -1157,7 +1387,7 @@ main(int argc, char **argv)
          }
       }
 
-      if (color_type == 8)
+      if (color_type == 8 && isdigit(arg[0]))
       {
          color_type = atoi(arg);
          if (color_type < 0 || color_type > 6 || color_type == 1 ||
@@ -1170,7 +1400,7 @@ main(int argc, char **argv)
          continue;
       }
 
-      if (bit_depth == 32)
+      if (bit_depth == 32 && isdigit(arg[0]))
       {
          bit_depth = atoi(arg);
          if (bit_depth <= 0 || bit_depth > 16 ||
@@ -1203,13 +1433,50 @@ main(int argc, char **argv)
    if (color_type == 8 || bit_depth == 32)
    {
       fprintf(stderr, "usage: makepng [--sRGB|--linear|--1.8] "
-         "color-type bit-depth [file-name]\n"
+         "[--color=...] color-type bit-depth [file-name]\n"
          "  Make a test PNG file, by default writes to stdout.\n");
       exit(1);
    }
 
+   /* Check the colors */
    {
-      int ret = write_png(fp, color_type, bit_depth, gamma, head_insert);
+      const unsigned int lim = (color_type == PNG_COLOR_TYPE_PALETTE ? 255U :
+         (1U<<bit_depth)-1);
+      unsigned int i;
+
+      for (i=1; i<=colors[0]; ++i)
+         if (colors[i] > lim)
+         {
+            fprintf(stderr, "makepng: --color=...: %u out of range [0..%u]\n",
+               colors[i], lim);
+            exit(1);
+         }
+   }
+
+   /* Restrict the filters for more speed to those we know are used for the
+    * generated images.
+    */
+   if (filters == PNG_ALL_FILTERS)
+   {
+      if ((color_type & PNG_COLOR_MASK_PALETTE) != 0 || bit_depth < 8)
+         filters = PNG_FILTER_NONE;
+
+      else if (color_type & PNG_COLOR_MASK_COLOR) /* rgb */
+      {
+         if (bit_depth == 8)
+            filters &= ~(PNG_FILTER_NONE | PNG_FILTER_AVG);
+
+         else
+            filters = PNG_FILTER_SUB | PNG_FILTER_PAETH;
+      }
+
+      else /* gray 8 or 16-bit */
+         filters &= ~PNG_FILTER_NONE;
+   }
+
+   {
+      int ret = write_png(&file_name, fp, color_type, bit_depth, gamma,
+         head_insert, filters, colors);
 
       if (ret != 0 && file_name != NULL)
          remove(file_name);

contrib/libtests/pngstest.c

@@ -22,7 +22,7 @@
 #include <ctype.h>
 #include <math.h>
 
-#if (defined HAVE_CONFIG_H) && !(defined PNG_NO_CONFIG_H)
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
 #  include <config.h>
 #endif
 
@@ -35,11 +35,12 @@
 #  include "../../png.h"
 #endif
 
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED /* Else nothing can be done */
 #include "../tools/sRGB.h"
 
 /* KNOWN ISSUES
  *
- * These defines switch on alternate algorithms for format convertions to match
+ * These defines switch on alternate algorithms for format conversions to match
  * the current libpng implementation; they are set to allow pngstest to pass
  * even though libpng is producing answers that are not as correct as they
  * should be.
@@ -61,6 +62,12 @@
 #  define aligncastconst(type, value) ((const void*)(value))
 #endif /* __cplusplus */
 
+/* During parallel runs of pngstest each temporary file needs a unique name,
+ * this is used to permit uniqueness using a command line argument which can be
+ * up to 22 characters long.
+ */
+static char tmpf[23] = "TMP";
+
 /* Generate random bytes.  This uses a boring repeatable algorithm and it
  * is implemented here so that it gives the same set of numbers on every
  * architecture.  It's a linear congruential generator (Knuth or Sedgewick
@@ -124,7 +131,7 @@ u16d(double d)
 }
 
 /* sRGB support: use exact calculations rounded to the nearest int, see the
- * fesetround() call in main().  sRGB_to_d optimizes the 8 to 16-bit convertion.
+ * fesetround() call in main().  sRGB_to_d optimizes the 8 to 16-bit conversion.
  */
 static double sRGB_to_d[256];
 static double g22_to_d[256];
@@ -235,7 +242,7 @@ power_law_error16(int value)
    if (value > 0 && value < 65535)
    {
       /* Round trip the value through an 8-bit representation but using
-       * non-matching to/from convertions.
+       * non-matching to/from conversions.
        */
       double vd = value / 65535.;
       double e = fabs(
@@ -308,6 +315,7 @@ compare_16bit(int v1, int v2, int error_limit, int multiple_algorithms)
 #define KEEP_GOING 32
 #define ACCUMULATE 64
 #define FAST_WRITE 128
+#define sRGB_16BIT 256
 
 static void
 print_opts(png_uint_32 opts)
@@ -328,6 +336,8 @@ print_opts(png_uint_32 opts)
       printf(" --accumulate");
    if (!(opts & FAST_WRITE)) /* --fast is currently the default */
       printf(" --slow");
+   if (opts & sRGB_16BIT)
+      printf(" --sRGB-16bit");
 }
 
 #define FORMAT_NO_CHANGE 0x80000000 /* additional flag */
@@ -507,14 +517,23 @@ static void format_default(format_list *pf, int redundant)
 
       for (f=0; f<FORMAT_COUNT; ++f)
       {
-         /* Eliminate redundant settings. */
-         /* BGR is meaningless if no color: */
-         if ((f & PNG_FORMAT_FLAG_COLOR) == 0 && (f & PNG_FORMAT_FLAG_BGR) != 0)
+         /* Eliminate redundant and unsupported settings. */
+#        ifdef PNG_FORMAT_BGR_SUPPORTED
+            /* BGR is meaningless if no color: */
+            if ((f & PNG_FORMAT_FLAG_COLOR) == 0 &&
+               (f & PNG_FORMAT_FLAG_BGR) != 0)
+#        else
+            if ((f & 0x10U/*HACK: fixed value*/) != 0)
+#        endif
             continue;
 
          /* AFIRST is meaningless if no alpha: */
-         if ((f & PNG_FORMAT_FLAG_ALPHA) == 0 &&
-            (f & PNG_FORMAT_FLAG_AFIRST) != 0)
+#        ifdef PNG_FORMAT_AFIRST_SUPPORTED
+            if ((f & PNG_FORMAT_FLAG_ALPHA) == 0 &&
+               (f & PNG_FORMAT_FLAG_AFIRST) != 0)
+#        else
+            if ((f & 0x20U/*HACK: fixed value*/) != 0)
+#        endif
             continue;
 
          format_set(pf, f);
@@ -776,6 +795,7 @@ gp_ga8(Pixel *p, png_const_voidp pb)
    p->a = pp[1];
 }
 
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
 static void
 gp_ag8(Pixel *p, png_const_voidp pb)
 {
@@ -784,6 +804,7 @@ gp_ag8(Pixel *p, png_const_voidp pb)
    p->r = p->g = p->b = pp[1];
    p->a = pp[0];
 }
+#endif
 
 static void
 gp_rgb8(Pixel *p, png_const_voidp pb)
@@ -796,6 +817,7 @@ gp_rgb8(Pixel *p, png_const_voidp pb)
    p->a = 255;
 }
 
+#ifdef PNG_FORMAT_BGR_SUPPORTED
 static void
 gp_bgr8(Pixel *p, png_const_voidp pb)
 {
@@ -806,6 +828,7 @@ gp_bgr8(Pixel *p, png_const_voidp pb)
    p->b = pp[0];
    p->a = 255;
 }
+#endif
 
 static void
 gp_rgba8(Pixel *p, png_const_voidp pb)
@@ -818,6 +841,7 @@ gp_rgba8(Pixel *p, png_const_voidp pb)
    p->a = pp[3];
 }
 
+#ifdef PNG_FORMAT_BGR_SUPPORTED
 static void
 gp_bgra8(Pixel *p, png_const_voidp pb)
 {
@@ -828,7 +852,9 @@ gp_bgra8(Pixel *p, png_const_voidp pb)
    p->b = pp[0];
    p->a = pp[3];
 }
+#endif
 
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
 static void
 gp_argb8(Pixel *p, png_const_voidp pb)
 {
@@ -839,7 +865,9 @@ gp_argb8(Pixel *p, png_const_voidp pb)
    p->b = pp[3];
    p->a = pp[0];
 }
+#endif
 
+#if defined(PNG_FORMAT_AFIRST_SUPPORTED) && defined(PNG_FORMAT_BGR_SUPPORTED)
 static void
 gp_abgr8(Pixel *p, png_const_voidp pb)
 {
@@ -850,6 +878,7 @@ gp_abgr8(Pixel *p, png_const_voidp pb)
    p->b = pp[1];
    p->a = pp[0];
 }
+#endif
 
 static void
 gp_g16(Pixel *p, png_const_voidp pb)
@@ -869,6 +898,7 @@ gp_ga16(Pixel *p, png_const_voidp pb)
    p->a = pp[1];
 }
 
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
 static void
 gp_ag16(Pixel *p, png_const_voidp pb)
 {
@@ -877,6 +907,7 @@ gp_ag16(Pixel *p, png_const_voidp pb)
    p->r = p->g = p->b = pp[1];
    p->a = pp[0];
 }
+#endif
 
 static void
 gp_rgb16(Pixel *p, png_const_voidp pb)
@@ -889,6 +920,7 @@ gp_rgb16(Pixel *p, png_const_voidp pb)
    p->a = 65535;
 }
 
+#ifdef PNG_FORMAT_BGR_SUPPORTED
 static void
 gp_bgr16(Pixel *p, png_const_voidp pb)
 {
@@ -899,6 +931,7 @@ gp_bgr16(Pixel *p, png_const_voidp pb)
    p->b = pp[0];
    p->a = 65535;
 }
+#endif
 
 static void
 gp_rgba16(Pixel *p, png_const_voidp pb)
@@ -911,6 +944,7 @@ gp_rgba16(Pixel *p, png_const_voidp pb)
    p->a = pp[3];
 }
 
+#ifdef PNG_FORMAT_BGR_SUPPORTED
 static void
 gp_bgra16(Pixel *p, png_const_voidp pb)
 {
@@ -921,7 +955,9 @@ gp_bgra16(Pixel *p, png_const_voidp pb)
    p->b = pp[0];
    p->a = pp[3];
 }
+#endif
 
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
 static void
 gp_argb16(Pixel *p, png_const_voidp pb)
 {
@@ -932,7 +968,9 @@ gp_argb16(Pixel *p, png_const_voidp pb)
    p->b = pp[3];
    p->a = pp[0];
 }
+#endif
 
+#if defined(PNG_FORMAT_AFIRST_SUPPORTED) && defined(PNG_FORMAT_BGR_SUPPORTED)
 static void
 gp_abgr16(Pixel *p, png_const_voidp pb)
 {
@@ -943,6 +981,7 @@ gp_abgr16(Pixel *p, png_const_voidp pb)
    p->b = pp[1];
    p->a = pp[0];
 }
+#endif
 
 /* Given a format, return the correct one of the above functions. */
 static void (*
@@ -956,29 +995,35 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
    {
       if (format & PNG_FORMAT_FLAG_COLOR)
       {
-         if (format & PNG_FORMAT_FLAG_BGR)
-         {
-            if (format & PNG_FORMAT_FLAG_ALPHA)
+#        ifdef PNG_FORMAT_BGR_SUPPORTED
+            if (format & PNG_FORMAT_FLAG_BGR)
             {
-               if (format & PNG_FORMAT_FLAG_AFIRST)
-                  return gp_abgr16;
+               if (format & PNG_FORMAT_FLAG_ALPHA)
+               {
+#                 ifdef PNG_FORMAT_AFIRST_SUPPORTED
+                     if (format & PNG_FORMAT_FLAG_AFIRST)
+                        return gp_abgr16;
+
+                     else
+#                 endif
+                     return gp_bgra16;
+               }
 
                else
-                  return gp_bgra16;
+                  return gp_bgr16;
             }
 
             else
-               return gp_bgr16;
-         }
-
-         else
+#        endif
          {
             if (format & PNG_FORMAT_FLAG_ALPHA)
             {
-               if (format & PNG_FORMAT_FLAG_AFIRST)
-                  return gp_argb16;
+#              ifdef PNG_FORMAT_AFIRST_SUPPORTED
+                  if (format & PNG_FORMAT_FLAG_AFIRST)
+                     return gp_argb16;
 
-               else
+                  else
+#              endif
                   return gp_rgba16;
             }
 
@@ -991,10 +1036,12 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
       {
          if (format & PNG_FORMAT_FLAG_ALPHA)
          {
-            if (format & PNG_FORMAT_FLAG_AFIRST)
-               return gp_ag16;
+#           ifdef PNG_FORMAT_AFIRST_SUPPORTED
+               if (format & PNG_FORMAT_FLAG_AFIRST)
+                  return gp_ag16;
 
-            else
+               else
+#           endif
                return gp_ga16;
          }
 
@@ -1007,29 +1054,35 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
    {
       if (format & PNG_FORMAT_FLAG_COLOR)
       {
-         if (format & PNG_FORMAT_FLAG_BGR)
-         {
-            if (format & PNG_FORMAT_FLAG_ALPHA)
+#        ifdef PNG_FORMAT_BGR_SUPPORTED
+            if (format & PNG_FORMAT_FLAG_BGR)
             {
-               if (format & PNG_FORMAT_FLAG_AFIRST)
-                  return gp_abgr8;
+               if (format & PNG_FORMAT_FLAG_ALPHA)
+               {
+#                 ifdef PNG_FORMAT_AFIRST_SUPPORTED
+                     if (format & PNG_FORMAT_FLAG_AFIRST)
+                        return gp_abgr8;
+
+                     else
+#                 endif
+                     return gp_bgra8;
+               }
 
                else
-                  return gp_bgra8;
+                  return gp_bgr8;
             }
 
             else
-               return gp_bgr8;
-         }
-
-         else
+#        endif
          {
             if (format & PNG_FORMAT_FLAG_ALPHA)
             {
-               if (format & PNG_FORMAT_FLAG_AFIRST)
-                  return gp_argb8;
+#              ifdef PNG_FORMAT_AFIRST_SUPPORTED
+                  if (format & PNG_FORMAT_FLAG_AFIRST)
+                     return gp_argb8;
 
-               else
+                  else
+#              endif
                   return gp_rgba8;
             }
 
@@ -1042,10 +1095,12 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
       {
          if (format & PNG_FORMAT_FLAG_ALPHA)
          {
-            if (format & PNG_FORMAT_FLAG_AFIRST)
-               return gp_ag8;
+#           ifdef PNG_FORMAT_AFIRST_SUPPORTED
+               if (format & PNG_FORMAT_FLAG_AFIRST)
+                  return gp_ag8;
 
-            else
+               else
+#           endif
                return gp_ga8;
          }
 
@@ -1066,7 +1121,7 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
  * 3) Convert between 8-bit and 16-bit components.  (Both directtions are
  *    relevant.)
  *
- * This gives the following base format convertion matrix:
+ * This gives the following base format conversion matrix:
  *
  *   OUT:    ----- 8-bit -----    ----- 16-bit -----
  *   IN     G    GA   RGB  RGBA  G    GA   RGB  RGBA
@@ -1160,7 +1215,7 @@ gpc_nop6(Pixel *out, const Pixel *in, const Background *back)
 }
 #endif
 
-/* 8-bit to 8-bit convertions */
+/* 8-bit to 8-bit conversions */
 /* bckg: composite on gray background */
 static void
 gpc_bckg(Pixel *out, const Pixel *in, const Background *back)
@@ -1255,7 +1310,7 @@ gpc_g8b(Pixel *out, const Pixel *in, const Background *back)
    out->a = 255;
 }
 
-/* 8-bit to 16-bit convertions */
+/* 8-bit to 16-bit conversions */
 /* lin: make sRGB components linear, alpha := 65535 */
 static void
 gpc_lin(Pixel *out, const Pixel *in, const Background *back)
@@ -1412,7 +1467,7 @@ gpc_gprq(Pixel *out, const Pixel *in, const Background *back)
    out->a = 65535;
 }
 
-/* 8-bit to 16-bit convertions for gAMA 45455 encoded values */
+/* 8-bit to 16-bit conversions for gAMA 45455 encoded values */
 /* Lin: make gAMA 45455 components linear, alpha := 65535 */
 static void
 gpc_Lin(Pixel *out, const Pixel *in, const Background *back)
@@ -1583,7 +1638,7 @@ gpc_Gprq(Pixel *out, const Pixel *in, const Background *back)
 }
 #endif
 
-/* 16-bit to 8-bit convertions */
+/* 16-bit to 8-bit conversions */
 /* sRGB: convert linear components to sRGB, alpha := 255 */
 static void
 gpc_sRGB(Pixel *out, const Pixel *in, const Background *back)
@@ -1809,7 +1864,7 @@ gpc_cb16(Pixel *out, const Pixel *in, const Background *back)
    out->a = 255;
 }
 
-/* 16-bit to 16-bit convertions */
+/* 16-bit to 16-bit conversions */
 /* A:    set alpha to 65535 */
 static void
 gpc_A(Pixel *out, const Pixel *in, const Background *back)
@@ -1900,13 +1955,13 @@ static void (* const gpc_fn_colormapped[8/*in*/][8/*out*/])
 };
 
 /* The error arrays record the error in the same matrix; 64 entries, however
- * the different algorithms used in libpng for colormap and direct convertions
+ * the different algorithms used in libpng for colormap and direct conversions
  * mean that four separate matrices are used (for each combination of
  * colormapped and direct.)
  *
- * In some cases the convertion between sRGB formats goes via a linear
- * intermediate; an sRGB to linear convertion (as above) is followed by a simple
- * linear to sRGB step with no other convertions.  This is done by a separate
+ * In some cases the conversion between sRGB formats goes via a linear
+ * intermediate; an sRGB to linear conversion (as above) is followed by a simple
+ * linear to sRGB step with no other conversions.  This is done by a separate
  * error array from an arbitrary 'in' format to one of the four basic outputs
  * (since final output is always sRGB not colormapped).
  *
@@ -2120,7 +2175,7 @@ typedef struct
 }
 Transform;
 
-/* Return a 'transform' as above for the given format convertion. */
+/* Return a 'transform' as above for the given format conversion. */
 static void
 transform_from_formats(Transform *result, Image *in_image,
    const Image *out_image, png_const_colorp background, int via_linear)
@@ -2185,10 +2240,10 @@ transform_from_formats(Transform *result, Image *in_image,
 
    else
    {
-      /* The caller handles the colormap->pixel value convertion, so the
+      /* The caller handles the colormap->pixel value conversion, so the
        * transform function just gets a pixel value, however because libpng
        * currently contains a different implementation for mapping a colormap if
-       * both input and output are colormapped we need different convertion
+       * both input and output are colormapped we need different conversion
        * functions to deal with errors in the libpng implementation.
        */
       if (in_format & out_format & PNG_FORMAT_FLAG_COLORMAP)
@@ -2249,7 +2304,7 @@ transform_from_formats(Transform *result, Image *in_image,
                result->background_color.ir = background->red;
                result->background_color.ig = background->green;
                result->background_color.ib = background->blue;
-               /* TODO: sometimes libpng uses the power law convertion here, how
+               /* TODO: sometimes libpng uses the power law conversion here, how
                 * to handle this?
                 */
                result->background_color.dr = sRGB_to_d[background->red];
@@ -2262,7 +2317,7 @@ transform_from_formats(Transform *result, Image *in_image,
                result->background_color.ir =
                   result->background_color.ig =
                   result->background_color.ib = background->green;
-               /* TODO: sometimes libpng uses the power law convertion here, how
+               /* TODO: sometimes libpng uses the power law conversion here, how
                 * to handle this?
                 */
                result->background_color.dr =
@@ -2276,7 +2331,7 @@ transform_from_formats(Transform *result, Image *in_image,
             result->background_color.ir =
                result->background_color.ig =
                result->background_color.ib = BUFFER_INIT8;
-            /* TODO: sometimes libpng uses the power law convertion here, how
+            /* TODO: sometimes libpng uses the power law conversion here, how
              * to handle this?
              */
             result->background_color.dr =
@@ -2608,13 +2663,15 @@ component_loc(png_byte loc[4], png_uint_32 format)
 
       loc[2] = 1;
 
-      if (format & PNG_FORMAT_FLAG_BGR)
-      {
-         loc[1] = 2;
-         loc[3] = 0;
-      }
+#     ifdef PNG_FORMAT_BGR_SUPPORTED
+         if (format & PNG_FORMAT_FLAG_BGR)
+         {
+            loc[1] = 2;
+            loc[3] = 0;
+         }
 
-      else
+         else
+#     endif
       {
          loc[1] = 0;
          loc[3] = 2;
@@ -2624,20 +2681,22 @@ component_loc(png_byte loc[4], png_uint_32 format)
    else
    {
       channels = 1;
-      loc[0] = loc[1] = loc[2] = 0;
+      loc[1] = loc[2] = loc[3] = 0;
    }
 
    if (format & PNG_FORMAT_FLAG_ALPHA)
    {
-      if (format & PNG_FORMAT_FLAG_AFIRST)
-      {
-         loc[0] = 0;
-         ++loc[1];
-         ++loc[2];
-         ++loc[3];
-      }
+#     ifdef PNG_FORMAT_AFIRST_SUPPORTED
+         if (format & PNG_FORMAT_FLAG_AFIRST)
+         {
+            loc[0] = 0;
+            ++loc[1];
+            ++loc[2];
+            ++loc[3];
+         }
 
-      else
+         else
+#     endif
          loc[0] = channels;
 
       ++channels;
@@ -3007,17 +3066,29 @@ read_file(Image *image, png_uint_32 format, png_const_colorp background)
          return logerror(image, "memory init: ", image->file_name, "");
    }
 
-   else if (image->input_file != NULL)
-   {
-      if (!png_image_begin_read_from_stdio(&image->image, image->input_file))
-         return logerror(image, "stdio init: ", image->file_name, "");
-   }
+#  ifdef PNG_STDIO_SUPPORTED
+      else if (image->input_file != NULL)
+      {
+         if (!png_image_begin_read_from_stdio(&image->image, image->input_file))
+            return logerror(image, "stdio init: ", image->file_name, "");
+      }
 
-   else
-   {
-      if (!png_image_begin_read_from_file(&image->image, image->file_name))
-         return logerror(image, "file init: ", image->file_name, "");
-   }
+      else
+      {
+         if (!png_image_begin_read_from_file(&image->image, image->file_name))
+            return logerror(image, "file init: ", image->file_name, "");
+      }
+#  else
+      else
+      {
+         return logerror(image, "unsupported file/stdio init: ",
+            image->file_name, "");
+      }
+#  endif
+
+   /* This must be set after the begin_read call: */
+   if (image->opts & sRGB_16BIT)
+      image->image.flags |= PNG_IMAGE_FLAG_16BIT_sRGB;
 
    /* Have an initialized image with all the data we need plus, maybe, an
     * allocated file (myfile) or buffer (mybuffer) that need to be freed.
@@ -3152,6 +3223,7 @@ read_one_file(Image *image)
    return read_file(image, FORMAT_NO_CHANGE, NULL);
 }
 
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
 static int
 write_one_file(Image *output, Image *image, int convert_to_8bit)
 {
@@ -3196,7 +3268,7 @@ write_one_file(Image *output, Image *image, int convert_to_8bit)
       static int counter = 0;
       char name[32];
 
-      sprintf(name, "TMP%d.png", ++counter);
+      sprintf(name, "%s%d.png", tmpf, ++counter);
 
       if (png_image_write_to_file(&image->image, name, convert_to_8bit,
          image->buffer+16, (png_int_32)image->stride, image->colormap))
@@ -3240,6 +3312,7 @@ write_one_file(Image *output, Image *image, int convert_to_8bit)
       return logerror(output, output->tmpfile_name,
          ": read of new file failed", "");
 }
+#endif
 
 static int
 testimage(Image *image, png_uint_32 opts, format_list *pf)
@@ -3327,44 +3400,48 @@ testimage(Image *image, png_uint_32 opts, format_list *pf)
          if (!result)
             break;
 
-         /* Write the *copy* just made to a new file to make sure the write side
-          * works ok.  Check the conversion to sRGB if the copy is linear.
-          */
-         output.opts = opts;
-         result = write_one_file(&output, &copy, 0/*convert to 8bit*/);
-         if (!result)
-            break;
-
-         /* Validate against the original too; the background is needed here
-          * as well so that compare_two_images knows what color was used.
-          */
-         result = compare_two_images(image, &output, 0, background);
-         if (!result)
-            break;
-
-         if ((format & PNG_FORMAT_FLAG_LINEAR) != 0 &&
-            (format & PNG_FORMAT_FLAG_COLORMAP) == 0)
-         {
-            /* 'output' is linear, convert to the corresponding sRGB format. */
-            output.opts = opts;
-            result = write_one_file(&output, &copy, 1/*convert to 8bit*/);
-            if (!result)
-               break;
-
-            /* This may involve a conversion via linear; in the ideal world this
-             * would round-trip correctly, but libpng 1.5.7 is not the ideal
-             * world so allow a drift (error_via_linear).
-             *
-             * 'image' has an alpha channel but 'output' does not then there
-             * will a strip-alpha-channel operation (because 'output' is
-             * linear), handle this by composing on black when doing the
-             * comparison.
+#        ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+            /* Write the *copy* just made to a new file to make sure the write
+             * side works ok.  Check the conversion to sRGB if the copy is
+             * linear.
              */
-            result = compare_two_images(image, &output, 1/*via_linear*/,
-               background);
+            output.opts = opts;
+            result = write_one_file(&output, &copy, 0/*convert to 8bit*/);
             if (!result)
                break;
-         }
+
+            /* Validate against the original too; the background is needed here
+             * as well so that compare_two_images knows what color was used.
+             */
+            result = compare_two_images(image, &output, 0, background);
+            if (!result)
+               break;
+
+            if ((format & PNG_FORMAT_FLAG_LINEAR) != 0 &&
+               (format & PNG_FORMAT_FLAG_COLORMAP) == 0)
+            {
+               /* 'output' is linear, convert to the corresponding sRGB format.
+                */
+               output.opts = opts;
+               result = write_one_file(&output, &copy, 1/*convert to 8bit*/);
+               if (!result)
+                  break;
+
+               /* This may involve a conversion via linear; in the ideal world
+                * this would round-trip correctly, but libpng 1.5.7 is not the
+                * ideal world so allow a drift (error_via_linear).
+                *
+                * 'image' has an alpha channel but 'output' does not then there
+                * will a strip-alpha-channel operation (because 'output' is
+                * linear), handle this by composing on black when doing the
+                * comparison.
+                */
+               result = compare_two_images(image, &output, 1/*via_linear*/,
+                  background);
+               if (!result)
+                  break;
+            }
+#        endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */
       }
 
       freeimage(&output);
@@ -3400,6 +3477,10 @@ test_one_file(const char *file_name, format_list *formats, png_uint_32 opts,
       else
          printf("FAIL:");
 
+#     ifndef PNG_SIMPLIFIED_WRITE_SUPPORTED
+         printf(" (no write)");
+#     endif
+
       print_opts(opts);
       printf(" %s\n", file_name);
       /* stdout may not be line-buffered if it is piped to a file, so: */
@@ -3442,11 +3523,19 @@ main(int argc, char **argv)
          memset(gpc_error_via_linear, 0, sizeof gpc_error_via_linear);
       }
       else if (strcmp(arg, "--file") == 0)
-         opts |= READ_FILE;
+#        ifdef PNG_STDIO_SUPPORTED
+            opts |= READ_FILE;
+#        else
+            return 77; /* skipped: no support */
+#        endif
       else if (strcmp(arg, "--memory") == 0)
          opts &= ~READ_FILE;
       else if (strcmp(arg, "--stdio") == 0)
-         opts |= USE_STDIO;
+#        ifdef PNG_STDIO_SUPPORTED
+            opts |= USE_STDIO;
+#        else
+            return 77; /* skipped: no support */
+#        endif
       else if (strcmp(arg, "--name") == 0)
          opts &= ~USE_STDIO;
       else if (strcmp(arg, "--verbose") == 0)
@@ -3471,6 +3560,34 @@ main(int argc, char **argv)
          opts &= ~KEEP_GOING;
       else if (strcmp(arg, "--strict") == 0)
          opts |= STRICT;
+      else if (strcmp(arg, "--sRGB-16bit") == 0)
+         opts |= sRGB_16BIT;
+      else if (strcmp(arg, "--linear-16bit") == 0)
+         opts &= ~sRGB_16BIT;
+      else if (strcmp(arg, "--tmpfile") == 0)
+      {
+         if (c+1 < argc)
+         {
+            if (strlen(argv[++c]) >= sizeof tmpf)
+            {
+               fflush(stdout);
+               fprintf(stderr, "%s: %s is too long for a temp file prefix\n",
+                  argv[0], argv[c]);
+               exit(99);
+            }
+
+            /* Safe: checked above */
+            strcpy(tmpf, argv[c]);
+         }
+
+         else
+         {
+            fflush(stdout);
+            fprintf(stderr, "%s: %s requires a temporary file prefix\n",
+               argv[0], arg);
+            exit(99);
+         }
+      }
       else if (strcmp(arg, "--touch") == 0)
       {
          if (c+1 < argc)
@@ -3481,7 +3598,7 @@ main(int argc, char **argv)
             fflush(stdout);
             fprintf(stderr, "%s: %s requires a file name argument\n",
                argv[0], arg);
-            exit(1);
+            exit(99);
          }
       }
       else if (arg[0] == '+')
@@ -3489,7 +3606,7 @@ main(int argc, char **argv)
          png_uint_32 format = formatof(arg+1);
 
          if (format > FORMAT_COUNT)
-            exit(1);
+            exit(99);
 
          format_set(&formats, format);
       }
@@ -3497,7 +3614,7 @@ main(int argc, char **argv)
       {
          fflush(stdout);
          fprintf(stderr, "%s: unknown option: %s\n", argv[0], arg);
-         exit(1);
+         exit(99);
       }
       else
       {
@@ -3546,7 +3663,7 @@ main(int argc, char **argv)
                buffer[4095] = 0;
                fprintf(stderr, "%s...%s: file name too long\n", buffer,
                   buffer+(4096-32));
-               exit(1);
+               exit(99);
             }
          }
 
@@ -3665,7 +3782,7 @@ main(int argc, char **argv)
          {
             fflush(stdout);
             fprintf(stderr, "%s: write failed\n", touch);
-            exit(1);
+            exit(99);
          }
       }
 
@@ -3673,9 +3790,18 @@ main(int argc, char **argv)
       {
          fflush(stdout);
          fprintf(stderr, "%s: open failed\n", touch);
-         exit(1);
+         exit(99);
       }
    }
 
    return retval;
 }
+
+#else /* !PNG_SIMPLIFIED_READ_SUPPORTED */
+int main(void)
+{
+   fprintf(stderr, "pngstest: no read support in libpng, test skipped\n");
+   /* So the test is skipped: */
+   return 77;
+}
+#endif /* PNG_SIMPLIFIED_READ_SUPPORTED */

contrib/libtests/readpng.c

@@ -0,0 +1,104 @@
+/* readpng.c
+ *
+ * Copyright (c) 2013 John Cunningham Bowler
+ *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Load an arbitrary number of PNG files (from the command line, or, if there
+ * are no arguments on the command line, from stdin) then run a time test by
+ * reading each file by row.  The test does nothing with the read result and
+ * does no transforms.  The only output is a time as a floating point number of
+ * seconds with 9 decimal digits.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
+#  include <config.h>
+#endif
+
+/* Define the following to use this test against your installed libpng, rather
+ * than the one being built here:
+ */
+#ifdef PNG_FREESTANDING_TESTS
+#  include <png.h>
+#else
+#  include "../../png.h"
+#endif
+
+static int
+read_png(FILE *fp)
+{
+   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+   png_infop info_ptr = NULL;
+   png_bytep row = NULL, display = NULL;
+
+   if (png_ptr == NULL)
+      return 0;
+
+   if (setjmp(png_jmpbuf(png_ptr)))
+   {
+      png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+      if (row != NULL) free(row);
+      if (display != NULL) free(display);
+      return 0;
+   }
+
+   png_init_io(png_ptr, fp);
+
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
+      png_error(png_ptr, "OOM allocating info structure");
+
+   png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS, NULL, 0);
+
+   png_read_info(png_ptr, info_ptr);
+
+   {
+      png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+
+      row = malloc(rowbytes);
+      display = malloc(rowbytes);
+
+      if (row == NULL || display == NULL)
+         png_error(png_ptr, "OOM allocating row buffers");
+
+      {
+         png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
+         int passes = png_set_interlace_handling(png_ptr);
+         int pass;
+
+         png_start_read_image(png_ptr);
+
+         for (pass = 0; pass < passes; ++pass)
+         {
+            png_uint_32 y = height;
+
+            /* NOTE: this trashes the row each time; interlace handling won't
+             * work, but this avoids memory thrashing for speed testing.
+             */
+            while (y-- > 0)
+               png_read_row(png_ptr, row, display);
+         }
+      }
+   }
+
+   /* Make sure to read to the end of the file: */
+   png_read_end(png_ptr, info_ptr);
+   png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+   free(row);
+   free(display);
+   return 1;
+}
+
+int
+main(void)
+{
+   /* Exit code 0 on success. */
+   return !read_png(stdin);
+}

contrib/libtests/tarith.c

@@ -92,12 +92,12 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
          showall = 1;
       else if (strcmp(*argv, "-e") == 0 && argc > 0)
       {
-	 --argc;
+         --argc;
          max_error = atof(*++argv);
       }
       else if (strcmp(*argv, "-E") == 0 && argc > 0)
       {
-	 --argc;
+         --argc;
          max_error_abs = atof(*++argv);
       }
       else
@@ -118,7 +118,7 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
          ++nonfinite;
 
       if (verbose)
-	 fprintf(stderr, "%.*g %d\n", DBL_DIG, test, precision);
+         fprintf(stderr, "%.*g %d\n", DBL_DIG, test, precision);
 
       /* Check for overflow in the buffer by setting a marker. */
       memset(buffer, 71, sizeof buffer);
@@ -131,8 +131,8 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
       if (buffer[precision+7] != 71)
       {
          fprintf(stderr, "%g[%d] -> '%s'[%lu] buffer overflow\n", test,
-	    precision, buffer, (unsigned long)strlen(buffer));
-	 failed = 1;
+            precision, buffer, (unsigned long)strlen(buffer));
+         failed = 1;
       }
 
       /* Following are used for the number parser below and must be
@@ -143,19 +143,19 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
       if (!isfinite(test))
       {
          /* Expect 'inf' */
-	 if (test >= 0 && strcmp(buffer, "inf") ||
-	     test <  0 && strcmp(buffer, "-inf"))
-	 {
-	    fprintf(stderr, "%g[%d] -> '%s' but expected 'inf'\n", test,
-	       precision, buffer);
-	    failed = 1;
-	 }
+         if (test >= 0 && strcmp(buffer, "inf") ||
+             test <  0 && strcmp(buffer, "-inf"))
+         {
+            fprintf(stderr, "%g[%d] -> '%s' but expected 'inf'\n", test,
+               precision, buffer);
+            failed = 1;
+         }
       }
       else if (!png_check_fp_number(buffer, precision+10, &state, &index) ||
           buffer[index] != 0)
       {
-	 fprintf(stderr, "%g[%d] -> '%s' but has bad format ('%c')\n", test,
-	 precision, buffer, buffer[index]);
+         fprintf(stderr, "%g[%d] -> '%s' but has bad format ('%c')\n", test,
+         precision, buffer, buffer[index]);
          failed = 1;
       }
       else if (PNG_FP_IS_NEGATIVE(state) && !(test < 0))
@@ -185,21 +185,21 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
       else
       {
          /* Check the result against the original. */
-	 double out = atof(buffer);
-	 double change = fabs((out - test)/test);
-	 double allow = .5/pow(10,
+         double out = atof(buffer);
+         double change = fabs((out - test)/test);
+         double allow = .5/pow(10,
             (precision >= DBL_DIG) ? DBL_DIG-1 : precision-1);
 
-	 /* NOTE: if you hit this error case are you compiling with gcc
-	  * and -O0?  Try -O2 - the errors can accumulate if the FP
-	  * code above is not optimized and may drift outside the .5 in
-	  * DBL_DIG allowed.  In any case a small number of errors may
-	  * occur (very small ones - 1 or 2%) because of rounding in the
-	  * calculations, either in the convertion API or in atof.
-	  */
-	 if (change >= allow && (isfinite(out) ||
-	     fabs(test/DBL_MAX) <= 1-allow))
-	 {
+         /* NOTE: if you hit this error case are you compiling with gcc
+          * and -O0?  Try -O2 - the errors can accumulate if the FP
+          * code above is not optimized and may drift outside the .5 in
+          * DBL_DIG allowed.  In any case a small number of errors may
+          * occur (very small ones - 1 or 2%) because of rounding in the
+          * calculations, either in the conversion API or in atof.
+          */
+         if (change >= allow && (isfinite(out) ||
+             fabs(test/DBL_MAX) <= 1-allow))
+         {
             double percent = (precision >= DBL_DIG) ? max_error_abs : max_error;
             double allowp = (change-allow)*100/allow;
 
@@ -213,16 +213,16 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
                if (max < allowp) max = allowp;
             }
 
-	    if (showall || allowp >= percent)
-	    {
-	       fprintf(stderr,
-		  "%.*g[%d] -> '%s' -> %.*g number changed (%g > %g (%d%%))\n",
-		  DBL_DIG, test, precision, buffer, DBL_DIG, out, change, allow,
-		  (int)round(allowp));
-	       failed = 1;
-	    }
-	    else
-	       ++minorarith;
+            if (showall || allowp >= percent)
+            {
+               fprintf(stderr,
+                  "%.*g[%d] -> '%s' -> %.*g number changed (%g > %g (%d%%))\n",
+                  DBL_DIG, test, precision, buffer, DBL_DIG, out, change, allow,
+                  (int)round(allowp));
+               failed = 1;
+            }
+            else
+               ++minorarith;
          }
       }
 
@@ -239,15 +239,15 @@ skip:
 
       /* Generate random numbers. */
       if (test == 0 || !isfinite(test))
-	 test = precision+1;
+         test = precision+1;
       else
       {
-	 /* Derive the exponent from the previous rand() value. */
-	 int exponent = precision % (DBL_MAX_EXP - DBL_MIN_EXP) + DBL_MIN_EXP;
-	 int tmp;
-	 test = frexp(test * rand(), &tmp);
-	 test = ldexp(test, exponent);
-	 precision >>= 8; /* arbitrary */
+         /* Derive the exponent from the previous rand() value. */
+         int exponent = precision % (DBL_MAX_EXP - DBL_MIN_EXP) + DBL_MIN_EXP;
+         int tmp;
+         test = frexp(test * rand(), &tmp);
+         test = ldexp(test, exponent);
+         precision >>= 8; /* arbitrary */
       }
 
       /* This limits the precision to 32 digits, enough for standard
@@ -646,17 +646,17 @@ int validation_muldiv(int count, int argc, char **argv)
        */
       {
          long u1, u2;
-	 int n = 0;
-	 if (a < 0) u1 = -a, n = 1; else u1 = a;
-	 if (times < 0) u2 = -times, n = !n; else u2 = times;
-	 png_64bit_product(u1, u2, &hi, &lo);
-	 if (n)
-	 {
-	    /* -x = ~x+1 */
-	    lo = ((~lo) + 1) & 0xffffffff;
-	    hi = ~hi;
-	    if (lo == 0) ++hi;
-	 }
+         int n = 0;
+         if (a < 0) u1 = -a, n = 1; else u1 = a;
+         if (times < 0) u2 = -times, n = !n; else u2 = times;
+         png_64bit_product(u1, u2, &hi, &lo);
+         if (n)
+         {
+            /* -x = ~x+1 */
+            lo = ((~lo) + 1) & 0xffffffff;
+            hi = ~hi;
+            if (lo == 0) ++hi;
+         }
       }
 
       fp = a;
@@ -664,48 +664,48 @@ int validation_muldiv(int count, int argc, char **argv)
       if ((fp & 0xffffffff) != lo || ((fp >> 32) & 0xffffffff) != hi)
       {
          fprintf(stderr, "png_64bit_product %d * %d -> %lx|%.8lx not %llx\n",
-	    a, times, hi, lo, fp);
-	 ++error64;
+            a, times, hi, lo, fp);
+         ++error64;
       }
 
       if (div != 0)
       {
-	 /* Round - this is C round to zero. */
-	 if ((fp < 0) != (div < 0))
-	   fp -= div/2;
-	 else
-	   fp += div/2;
+         /* Round - this is C round to zero. */
+         if ((fp < 0) != (div < 0))
+           fp -= div/2;
+         else
+           fp += div/2;
 
-	 fp /= div;
-	 fpround = fp;
-	 /* Assume 2's complement here: */
-	 ok = fpround <= PNG_UINT_31_MAX &&
-	      fpround >= -1-(long long int)PNG_UINT_31_MAX;
-	 if (!ok) ++overflow;
+         fp /= div;
+         fpround = fp;
+         /* Assume 2's complement here: */
+         ok = fpround <= PNG_UINT_31_MAX &&
+              fpround >= -1-(long long int)PNG_UINT_31_MAX;
+         if (!ok) ++overflow;
       }
       else
         ok = 0, ++overflow, fpround = fp/*misleading*/;
 
       if (verbose)
          fprintf(stderr, "TEST %d * %d / %d -> %lld (%s)\n", a, times, div,
-	    fp, ok ? "ok" : "overflow");
+            fp, ok ? "ok" : "overflow");
 
       ++tested;
       if (png_muldiv(&result, a, times, div) != ok)
       {
-	 ++error;
-	 if (ok)
-	     fprintf(stderr, "%d * %d / %d -> overflow (expected %lld)\n", a,
-	        times, div, fp);
+         ++error;
+         if (ok)
+             fprintf(stderr, "%d * %d / %d -> overflow (expected %lld)\n", a,
+                times, div, fp);
          else
-	     fprintf(stderr, "%d * %d / %d -> %d (expected overflow %lld)\n", a,
-	        times, div, result, fp);
+             fprintf(stderr, "%d * %d / %d -> %d (expected overflow %lld)\n", a,
+                times, div, result, fp);
       }
       else if (ok && result != fpround)
       {
          ++error;
          fprintf(stderr, "%d * %d / %d -> %d not %lld\n", a, times, div, result,
-	    fp);
+            fp);
       }
       else
          ++passed;
@@ -775,7 +775,7 @@ int validation_gamma(int argc, char **argv)
    /* Silence the output with -s, just test the gamma functions with -g: */
    while (--argc > 0)
       if (strcmp(*++argv, "-s") == 0)
-	 silent = 1;
+         silent = 1;
       else if (strcmp(*argv, "-g") == 0)
          onlygamma = 1;
       else
@@ -790,100 +790,100 @@ int validation_gamma(int argc, char **argv)
       maxerr = 0;
       for (i=0; i<256; ++i)
       {
-	 double correct = -log(i/255.)/log(2.)*65536;
-	 double error = png_log8bit(i) - correct;
+         double correct = -log(i/255.)/log(2.)*65536;
+         double error = png_log8bit(i) - correct;
 
-	 if (i != 0 && fabs(error) > maxerr)
-	    maxerr = fabs(error);
+         if (i != 0 && fabs(error) > maxerr)
+            maxerr = fabs(error);
 
-	 if (i == 0 && png_log8bit(i) != 0xffffffff ||
-	     i != 0 && png_log8bit(i) != floor(correct+.5))
-	 {
-	    fprintf(stderr, "8 bit log error: %d: got %u, expected %f\n",
-	       i, png_log8bit(i), correct);
-	 }
+         if (i == 0 && png_log8bit(i) != 0xffffffff ||
+             i != 0 && png_log8bit(i) != floor(correct+.5))
+         {
+            fprintf(stderr, "8 bit log error: %d: got %u, expected %f\n",
+               i, png_log8bit(i), correct);
+         }
       }
 
       if (!silent)
-	 printf("maximum 8 bit log error = %f\n", maxerr);
+         printf("maximum 8 bit log error = %f\n", maxerr);
 
       maxerr = 0;
       for (i=0; i<65536; ++i)
       {
-	 double correct = -log(i/65535.)/log(2.)*65536;
-	 double error = png_log16bit(i) - correct;
+         double correct = -log(i/65535.)/log(2.)*65536;
+         double error = png_log16bit(i) - correct;
 
-	 if (i != 0 && fabs(error) > maxerr)
-	    maxerr = fabs(error);
+         if (i != 0 && fabs(error) > maxerr)
+            maxerr = fabs(error);
 
-	 if (i == 0 && png_log16bit(i) != 0xffffffff ||
-	     i != 0 && png_log16bit(i) != floor(correct+.5))
-	 {
-	    if (error > .68) /* By experiment error is less than .68 */
-	    {
-	       fprintf(stderr, "16 bit log error: %d: got %u, expected %f"
-		  " error: %f\n", i, png_log16bit(i), correct, error);
-	    }
-	 }
+         if (i == 0 && png_log16bit(i) != 0xffffffff ||
+             i != 0 && png_log16bit(i) != floor(correct+.5))
+         {
+            if (error > .68) /* By experiment error is less than .68 */
+            {
+               fprintf(stderr, "16 bit log error: %d: got %u, expected %f"
+                  " error: %f\n", i, png_log16bit(i), correct, error);
+            }
+         }
       }
 
       if (!silent)
-	 printf("maximum 16 bit log error = %f\n", maxerr);
+         printf("maximum 16 bit log error = %f\n", maxerr);
 
       /* Now exponentiations. */
       maxerr = 0;
       for (i=0; i<=0xfffff; ++i)
       {
-	 double correct = exp(-i/65536. * log(2.)) * (65536. * 65536);
-	 double error = png_exp(i) - correct;
+         double correct = exp(-i/65536. * log(2.)) * (65536. * 65536);
+         double error = png_exp(i) - correct;
 
-	 if (fabs(error) > maxerr)
-	    maxerr = fabs(error);
-	 if (fabs(error) > 1883) /* By experiment. */
-	 {
-	    fprintf(stderr, "32 bit exp error: %d: got %u, expected %f"
-		  " error: %f\n", i, png_exp(i), correct, error);
-	 }
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (fabs(error) > 1883) /* By experiment. */
+         {
+            fprintf(stderr, "32 bit exp error: %d: got %u, expected %f"
+                  " error: %f\n", i, png_exp(i), correct, error);
+         }
       }
 
       if (!silent)
-	 printf("maximum 32 bit exp error = %f\n", maxerr);
+         printf("maximum 32 bit exp error = %f\n", maxerr);
 
       maxerr = 0;
       for (i=0; i<=0xfffff; ++i)
       {
-	 double correct = exp(-i/65536. * log(2.)) * 255;
-	 double error = png_exp8bit(i) - correct;
+         double correct = exp(-i/65536. * log(2.)) * 255;
+         double error = png_exp8bit(i) - correct;
 
-	 if (fabs(error) > maxerr)
-	    maxerr = fabs(error);
-	 if (fabs(error) > .50002) /* By experiment */
-	 {
-	    fprintf(stderr, "8 bit exp error: %d: got %u, expected %f"
-		  " error: %f\n", i, png_exp8bit(i), correct, error);
-	 }
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (fabs(error) > .50002) /* By experiment */
+         {
+            fprintf(stderr, "8 bit exp error: %d: got %u, expected %f"
+                  " error: %f\n", i, png_exp8bit(i), correct, error);
+         }
       }
 
       if (!silent)
-	 printf("maximum 8 bit exp error = %f\n", maxerr);
+         printf("maximum 8 bit exp error = %f\n", maxerr);
 
       maxerr = 0;
       for (i=0; i<=0xfffff; ++i)
       {
-	 double correct = exp(-i/65536. * log(2.)) * 65535;
-	 double error = png_exp16bit(i) - correct;
+         double correct = exp(-i/65536. * log(2.)) * 65535;
+         double error = png_exp16bit(i) - correct;
 
-	 if (fabs(error) > maxerr)
-	    maxerr = fabs(error);
-	 if (fabs(error) > .524) /* By experiment */
-	 {
-	    fprintf(stderr, "16 bit exp error: %d: got %u, expected %f"
-		  " error: %f\n", i, png_exp16bit(i), correct, error);
-	 }
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (fabs(error) > .524) /* By experiment */
+         {
+            fprintf(stderr, "16 bit exp error: %d: got %u, expected %f"
+                  " error: %f\n", i, png_exp16bit(i), correct, error);
+         }
       }
 
       if (!silent)
-	 printf("maximum 16 bit exp error = %f\n", maxerr);
+         printf("maximum 16 bit exp error = %f\n", maxerr);
    } /* !onlygamma */
 
    /* Test the overall gamma correction. */
@@ -894,45 +894,45 @@ int validation_gamma(int argc, char **argv)
       png_fixed_point gfp = floor(g * PNG_FP_1 + .5);
 
       if (!silent)
-	 printf("Test gamma %f\n", g);
+         printf("Test gamma %f\n", g);
 
       maxerr = 0;
       for (j=0; j<256; ++j)
       {
          double correct = pow(j/255., g) * 255;
-	 png_byte out = png_gamma_8bit_correct(j, gfp);
-	 double error = out - correct;
+         png_byte out = png_gamma_8bit_correct(j, gfp);
+         double error = out - correct;
 
-	 if (fabs(error) > maxerr)
-	    maxerr = fabs(error);
-	 if (out != floor(correct+.5))
-	 {
-	    fprintf(stderr, "8bit %d ^ %f: got %d expected %f error %f\n",
-	       j, g, out, correct, error);
-	 }
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (out != floor(correct+.5))
+         {
+            fprintf(stderr, "8bit %d ^ %f: got %d expected %f error %f\n",
+               j, g, out, correct, error);
+         }
       }
 
       if (!silent)
-	 printf("gamma %f: maximum 8 bit error %f\n", g, maxerr);
+         printf("gamma %f: maximum 8 bit error %f\n", g, maxerr);
 
       maxerr = 0;
       for (j=0; j<65536; ++j)
       {
          double correct = pow(j/65535., g) * 65535;
-	 png_uint_16 out = png_gamma_16bit_correct(j, gfp);
-	 double error = out - correct;
+         png_uint_16 out = png_gamma_16bit_correct(j, gfp);
+         double error = out - correct;
 
-	 if (fabs(error) > maxerr)
-	    maxerr = fabs(error);
-	 if (fabs(error) > 1.62)
-	 {
-	    fprintf(stderr, "16bit %d ^ %f: got %d expected %f error %f\n",
-	       j, g, out, correct, error);
-	 }
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (fabs(error) > 1.62)
+         {
+            fprintf(stderr, "16bit %d ^ %f: got %d expected %f error %f\n",
+               j, g, out, correct, error);
+         }
       }
 
       if (!silent)
-	 printf("gamma %f: maximum 16 bit error %f\n", g, maxerr);
+         printf("gamma %f: maximum 16 bit error %f\n", g, maxerr);
    }
 
    return 0;
@@ -942,7 +942,7 @@ int validation_gamma(int argc, char **argv)
 /* Various validation routines are included herein, they require some
  * definition for png_warning and png_error, seetings of VALIDATION:
  *
- * 1: validates the ASCII to floating point convertions
+ * 1: validates the ASCII to floating point conversions
  * 2: validates png_muldiv
  * 3: accuracy test of fixed point gamma tables
  */

contrib/libtests/timepng.c

@@ -22,7 +22,7 @@
 
 #include <time.h>
 
-#if (defined HAVE_CONFIG_H) && !(defined PNG_NO_CONFIG_H)
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
 #  include <config.h>
 #endif
 
@@ -252,7 +252,7 @@ int main(int argc, char **argv)
 
          while (fgets(filename, FILENAME_MAX+1, stdin))
          {
-            int len = strlen(filename);
+            size_t len = strlen(filename);
 
             if (filename[len-1] == '\n')
             {

contrib/pngminim/decoder/makefile

@@ -14,7 +14,8 @@ LD=$(CC)
 RM=rm -f
 COPY=cp
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP -I. -O1
+CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1 -Wall
 
 C=.c
 O=.o
@@ -81,7 +82,7 @@ OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
 
 # note: dependencies do not work on implicit rule lines
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) $(CPPFLAGS) -c $(CFLAGS) $<
 
 # dependencies
 
@@ -95,16 +96,16 @@ pngm2pnm$(E): $(OBJS)
 # The CPP_FLAGS setting causes pngusr.h to be included in
 # both the build of pnglibconf.h and, subsequently, when
 # building libpng itself.
-$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
 	$(PNGSRC)/scripts/pnglibconf.dfa \
 	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
 	$(RM) pnglibconf.h pnglibconf.dfn
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
-	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) clean
 	$(RM) pngm2pnm$(O)
 	$(RM) pngm2pnm$(E)

contrib/pngminim/encoder/README

@@ -1,6 +1,6 @@
 This demonstrates the use of PNG_USER_CONFIG and pngusr.h
 
-The makefile builds a minimal write-only decoder with embedded libpng
+The makefile builds a minimal write-only encoder with embedded libpng
 and zlib.
 
 Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC

contrib/pngminim/encoder/makefile

@@ -14,7 +14,8 @@ LD=$(CC)
 RM=rm -f
 COPY=cp
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZIP -I. -O1
+CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1 -Wall
 
 C=.c
 O=.o
@@ -80,7 +81,7 @@ OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) $(CPPFLAGS) -c $(CFLAGS) $<
 
 # dependencies
 
@@ -94,16 +95,16 @@ pnm2pngm$(E): $(OBJS)
 # The CPP_FLAGS setting causes pngusr.h to be included in
 # both the build of pnglibconf.h and, subsequently, when
 # building libpng itself.
-$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
 	$(PNGSRC)/scripts/pnglibconf.dfa \
 	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
 	$(RM) pnglibconf.h pnglibconf.dfn
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
-	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) clean
 	$(RM) pnm2pngm$(O)
 	$(RM) pnm2pngm$(E)

contrib/pngminim/encoder/pngusr.dfa

@@ -14,6 +14,10 @@ everything = off
 
 option WRITE on
 
+# These 2 options are required if you need to read PBM (P1 or P4) files.
+option WRITE_INVERT on
+option WRITE_PACK on
+
 # You must choose fixed or floating point arithmetic:
 # option FLOATING_POINT on
 

contrib/pngminim/preader/makefile

@@ -30,7 +30,8 @@ XLIB = -L/usr/X11R6/lib -lX11
 #LIBS = $(XLIB)
 LIBS = $(XLIB) -lm                      #platforms that need libm
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP -I. $(XINC) -O1
+CPPFLAGS=-I. $(XINC) -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1 -Wall
 
 C=.c
 O=.o
@@ -96,7 +97,7 @@ OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) $(CPPFLAGS) -c $(CFLAGS) $<
 
 # dependencies
 
@@ -110,16 +111,16 @@ rpng2-x$(E): $(OBJS)
 # The CPP_FLAGS setting causes pngusr.h to be included in
 # both the build of pnglibconf.h and, subsequently, when
 # building libpng itself.
-$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
 	$(PNGSRC)/scripts/pnglibconf.dfa \
 	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
 	$(RM) pnglibconf.h pnglibconf.dfn
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
-	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) clean
 	$(RM) rpng2-x$(O)
 	$(RM) rpng2-x$(E)

contrib/pngminus/makefile.std

@@ -8,9 +8,9 @@ LD=$(CC)
 RM=rm -f
 
 #PNGPATH = /usr/local
-#PNGINC = -I$(PNGPATH)/include/libpng16
-#PNGLIB = -L$(PNGPATH)/lib -lpng16
-#PNGLIBS = $(PNGPATH)/lib/libpng16.a
+#PNGINC = -I$(PNGPATH)/include/libpng17
+#PNGLIB = -L$(PNGPATH)/lib -lpng17
+#PNGLIBS = $(PNGPATH)/lib/libpng17.a
 PNGINC = -I../..
 PNGLIB = -L../.. -lpng
 PNGLIBS = ../../libpng.a

contrib/pngminus/pnm2png.c

@@ -198,9 +198,9 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   char          height_token[16];
   char          maxval_token[16];
   int           color_type;
-  unsigned long   ul_width, ul_alpha_width;
-  unsigned long   ul_height, ul_alpha_height;
-  unsigned long   ul_maxval;
+  unsigned long   ul_width=0, ul_alpha_width=0;
+  unsigned long   ul_height=0, ul_alpha_height=0;
+  unsigned long   ul_maxval=0;
   png_uint_32   width, alpha_width;
   png_uint_32   height, alpha_height;
   png_uint_32   maxval;
@@ -210,6 +210,9 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   int           alpha_present;
   int           row, col;
   BOOL          raw, alpha_raw = FALSE;
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  BOOL          packed_bitmap = FALSE;
+#endif
   png_uint_32   tmp16;
   int           i;
 
@@ -222,9 +225,21 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   }
   else if ((type_token[1] == '1') || (type_token[1] == '4'))
   {
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
     raw = (type_token[1] == '4');
     color_type = PNG_COLOR_TYPE_GRAY;
+    get_token(pnm_file, width_token);
+    sscanf (width_token, "%lu", &ul_width);
+    width = (png_uint_32) ul_width;
+    get_token(pnm_file, height_token);
+    sscanf (height_token, "%lu", &ul_height);
+    height = (png_uint_32) ul_height;
     bit_depth = 1;
+    packed_bitmap = TRUE;
+#else
+    fprintf (stderr, "PNM2PNG built without PNG_WRITE_INVERT_SUPPORTED and \n");
+    fprintf (stderr, "PNG_WRITE_PACK_SUPPORTED can't read PBM (P1,P4) files\n");
+#endif
   }
   else if ((type_token[1] == '2') || (type_token[1] == '5'))
   {
@@ -343,8 +358,14 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
 
   alpha_present = (channels - 1) % 2;
 
-  /* row_bytes is the width x number of channels x (bit-depth / 8) */
-  row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  if (packed_bitmap)
+    /* row data is as many bytes as can fit width x channels x bit_depth */
+    row_bytes = (width * channels * bit_depth + 7) / 8;
+  else
+#endif
+    /* row_bytes is the width x number of channels x (bit-depth / 8) */
+    row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
 
   if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)
     return FALSE;
@@ -354,40 +375,48 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
 
   for (row = 0; row < height; row++)
   {
-    for (col = 0; col < width; col++)
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+    if (packed_bitmap) {
+      for (i = 0; i < row_bytes; i++)
+        /* png supports this format natively so no conversion is needed */
+        *pix_ptr++ = get_data (pnm_file, 8);
+    } else
+#endif
     {
-      for (i = 0; i < (channels - alpha_present); i++)
+      for (col = 0; col < width; col++)
       {
-        if (raw)
-          *pix_ptr++ = get_data (pnm_file, bit_depth);
-        else
-          if (bit_depth <= 8)
-            *pix_ptr++ = get_value (pnm_file, bit_depth);
+        for (i = 0; i < (channels - alpha_present); i++)
+        {
+          if (raw)
+            *pix_ptr++ = get_data (pnm_file, bit_depth);
           else
-          {
-            tmp16 = get_value (pnm_file, bit_depth);
-            *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
-            pix_ptr++;
-            *pix_ptr = (png_byte) (tmp16 & 0xFF);
-            pix_ptr++;
-          }
-      }
+            if (bit_depth <= 8)
+              *pix_ptr++ = get_value (pnm_file, bit_depth);
+            else
+            {
+              tmp16 = get_value (pnm_file, bit_depth);
+              *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
+              pix_ptr++;
+              *pix_ptr = (png_byte) (tmp16 & 0xFF);
+              pix_ptr++;
+            }
+        }
 
-      if (alpha) /* read alpha-channel from pgm file */
-      {
-        if (alpha_raw)
-          *pix_ptr++ = get_data (alpha_file, alpha_depth);
-        else
-          if (alpha_depth <= 8)
-            *pix_ptr++ = get_value (alpha_file, bit_depth);
+        if (alpha) /* read alpha-channel from pgm file */
+        {
+          if (alpha_raw)
+            *pix_ptr++ = get_data (alpha_file, alpha_depth);
           else
-          {
-            tmp16 = get_value (alpha_file, bit_depth);
-            *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
-            *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
-          }
-      } /* if alpha */
-
+            if (alpha_depth <= 8)
+              *pix_ptr++ = get_value (alpha_file, bit_depth);
+            else
+            {
+              tmp16 = get_value (alpha_file, bit_depth);
+              *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
+              *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
+            }
+        } /* if alpha */
+      } /* if packed_bitmap */
     } /* end for col */
   } /* end for row */
 
@@ -404,6 +433,14 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
     return FALSE;
   }
 
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  if (packed_bitmap == TRUE)
+  {
+    png_set_packing (png_ptr);
+    png_set_invert_mono (png_ptr);
+  }
+#endif
+
   /* setjmp() must be called in every function that calls a PNG-reading libpng function */
   if (setjmp (png_jmpbuf(png_ptr)))
   {
@@ -460,19 +497,32 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
 void get_token(FILE *pnm_file, char *token)
 {
   int i = 0;
+  int ret;
 
-  /* remove white-space */
+  /* remove white-space and comment lines */
   do
   {
-    token[i] = (unsigned char) fgetc (pnm_file);
+    ret = fgetc(pnm_file);
+    if (ret == '#') {
+      /* the rest of this line is a comment */
+      do
+      {
+        ret = fgetc(pnm_file);
+      }
+      while ((ret != '\n') && (ret != '\r') && (ret != EOF));
+    }
+    if (ret == EOF) break;
+    token[i] = (unsigned char) ret;
   }
   while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
 
   /* read string */
   do
   {
+    ret = fgetc(pnm_file);
+    if (ret == EOF) break;
     i++;
-    token[i] = (unsigned char) fgetc (pnm_file);
+    token[i] = (unsigned char) ret;
   }
   while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
 

contrib/tools/chunkhash.c

@@ -0,0 +1,437 @@
+/* chunkhash.c -- build a perfect hash code for the chunk names on stdin.
+ *
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2013.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Feed this program all the known chunks that libpng must recognize.  It will
+ * generate an appropriate hash key for the macro in pngpriv.h  To generate the
+ * list of chunks currently defined in png.h do this:
+ *
+ *    sed -n -e 's/^#define png_\(....\) PNG_U32.*$/\1/p' png.h
+ *
+ * An alternative to using this program is to pipe the output of the above
+ * through gperf, however the code generated by perf is somewhat more verbose
+ * and it doesn't generate as good a result (however it's a heck of a lot faster
+ * than this program!)
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <png.h> /* for the libpng types for this platform */
+
+/* The machine generated file is checked in, so this works and it obtains the
+ * definition of the PNG_CHUNK_HASH macro.  To change this definition only ever
+ * alter the strings below!
+ */
+#include "chunkhash.h"
+
+/* The best_ variables are local variables defined in the functions below.  When
+ * used in libpng code, however, they are just constants.
+ */
+#define PNG_CHUNK_HASH_MASK best_mask
+#define PNG_CHUNK_HASH_C0 best_c[0]
+#define PNG_CHUNK_HASH_C1 best_c[1]
+#define PNG_CHUNK_HASH_C2 best_c[2]
+#define PNG_CHUNK_HASH_C3 best_c[3]
+
+/* These strings contain the C text to copy into the new version of
+ * contrib/tools/chunkhash.c
+ */
+static const char *strings[] = {
+"/* chunkhash.h -- a perfect hash code for the chunk names in png.h",
+" *",
+" * Last changed in libpng 1.7.0 [(PENDING RELEASE)]",
+" *",
+" * THIS IS A MACHINE GENERATED FILE.  See contrib/tools/chunkhash.c for",
+" * copyright and other information.",
+" *",
+" * USAGE:  To include the PNG_CHUNK_HASH macro and associated definitions:",
+" *",
+" * #define PNG_CHUNKHASH_DEFS",
+" * #include \"contrib/tools/chunkhash.h\"",
+" *",
+" * To define the png_chunk_hash array used by the macro:",
+" *",
+" * #define PNG_CHUNKHASH_CODE",
+" * #include \"contrib/tools/chunkhash.h\"",
+" *",
+" * One or both of the defines must be given except when building chunkhash",
+" * itself.",
+" */",
+"#ifdef PNG_CHUNKHASH_DEFS",
+"#ifndef PNG_CHUNKHASH_H",
+"#define PNG_CHUNKHASH_H",
+"/* A perfect hash code - returns a value 0..(PNG_KNOWN_CHUNK_COUNT-1) and is",
+" * generated by the ridiculously simple program in contrib/tools/chunkhash.c",
+" *",
+" * The hash code used here multiplies each byte by a different constant to",
+" * return a single number:",
+" *",
+" *    b0 * c[0] + b1 * [c1] + b2 * c[2] + b3 * c[3]",
+" *",
+" * The values of the constants are found by search using the a table of",
+" * primes, including 0, and may be (in fact are at present) 0 for some of the",
+" * bytes, the compiler is expected to optimize multiply by zero, or one!",
+" *",
+" * The lookup table reduces the sparse result of the hash calculation to the",
+" * correct index values.  The chunks are indexed in the string order of the",
+" * png_uint_32 chunk names.",
+" */",
+0, /* HEADER definitions go here */
+"",
+"extern const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1];",
+"#endif /* !PNG_CHUNKHASH_H */",
+"#endif /* PNG_CHUNKHASH_DEFS */",
+"",
+"#ifndef PNG_CHUNK_HASH",
+"#define PNG_CHUNK_HASH(chunk) (png_chunk_hash[PNG_CHUNK_HASH_MASK & (\\",
+"      ((chunk) >> 24) * PNG_CHUNK_HASH_C0 +\\",
+"      ((chunk) >> 16) * PNG_CHUNK_HASH_C1 +\\",
+"      ((chunk) >>  8) * PNG_CHUNK_HASH_C2 +\\",
+"      ((chunk)      ) * PNG_CHUNK_HASH_C3)])",
+"#endif",
+"",
+"#ifdef PNG_CHUNKHASH_CODE",
+"#ifndef PNG_CHUNKHASH_C",
+"#define PNG_CHUNKHASH_C",
+"const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1] = {",
+0, /* png.c definitions go here */
+"};",
+"#endif /* !PNG_CHUNKHASH_C */",
+"#endif /* PNG_CHUNKHASH_CODE */",
+0 /* end of file */
+};
+
+#define CHUNK_COUNT_MAX 32
+   /* If necessary this is easy to increase; just don't use a png_uint_32
+    * bitmask below, however it doesn't seem likely that the limit will be hit
+    * any time soon.
+    */
+
+static const png_byte
+chunk_hash[256] =
+{
+   0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
+   22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+   41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
+   60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78,
+   79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97,
+   98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113,
+   114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128,
+   129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
+   144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158,
+   159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173,
+   174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188,
+   189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203,
+   204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218,
+   219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233,
+   234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248,
+   249, 250, 251, 252, 253, 254, 255
+};
+
+static void
+error(const char *string)
+{
+   fprintf(stderr, "chunkhash: %s\n", string);
+   exit(1);
+}
+
+/* Return a hash code for the given chunk; this is the same as the pngpriv.h
+ * macro, but parameterized.  The names of the parameters have to be chosen to
+ * match the above #defines.
+ */
+static png_uint_32
+test_hash(png_uint_32 chunk, const unsigned int *best_c, png_uint_32 best_mask)
+{
+#  define png_chunk_hash chunk_hash /* prevents lookup */
+      return PNG_CHUNK_HASH(chunk);
+#  undef png_chunk_hash
+}
+
+static void
+print_chunks(const png_uint_32 *chunks, unsigned int nchunks, png_uint_32 first,
+   png_uint_32 last, const unsigned int *best_c, png_uint_32 best_mask,
+   const png_byte *lut)
+{
+   /* 'last' is the last code to print plus 1, this is used to detect duplicates
+    * (which should not happen - if there are any it's an internal error!)
+    */
+   if (nchunks > 0)
+   {
+      /* Recursive algorithm; find the hash code of the next chunk, then print
+       * all remaining chunks with codes in the range first..code (including
+       * duplicates) and after print all remaining chunks with codes in the
+       * range (code+1)..last
+       */
+      const png_uint_32 chunk = *chunks++;
+#     define png_chunk_hash lut
+         const png_uint_32 code = PNG_CHUNK_HASH(chunk);
+#     undef png_chunk_hash
+
+      --nchunks;
+
+      /* The code might be out of the print range */
+      if (code >= first && code <= last)
+      {
+         if (code >= first) /* not time yet */
+            print_chunks(chunks, nchunks, first, code, best_c, best_mask, lut);
+
+         printf("#define PNG_CHUNK_%c%c%c%c_TAG %lu%s\n", (char)(chunk>>24),
+            (char)(chunk>>16), (char)(chunk>>8), (char)chunk,
+            (unsigned long)code, code == last ? " /* DUPLICATE */" : "");
+
+         if (code < last) /* still some to go */
+            print_chunks(chunks, nchunks, code+1, last, best_c, best_mask, lut);
+      }
+
+      else
+         print_chunks(chunks, nchunks, first, last, best_c, best_mask, lut);
+   }
+}
+
+static unsigned int primes[] =
+{
+   0, 1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67,
+   71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149,
+   151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229,
+   233, 239, 241, 251
+};
+
+#define NPRIMES ((sizeof primes)/(sizeof primes[0]))
+
+int
+main(void)
+{
+   /* Stdin should just contain chunk names, one per line */
+   png_uint_32 best_mask;
+   unsigned int best_c[4];
+   png_uint_32 chunks[CHUNK_COUNT_MAX];
+   png_byte known_chunk_count;
+
+   /* Not required; stop GCC whining: */
+   memset(best_c, 0xab, sizeof best_c);
+   best_mask = 0x12345678;
+
+   {
+      png_uint_32 this_chunk = 0;
+      png_byte n_chunks = 0;
+
+      for (;;)
+      {
+         int ch = getchar();
+
+         if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z'))
+         {
+            if (this_chunk > 0xffffffU)
+               error("chunk name too long");
+
+            this_chunk = (this_chunk << 8) + (unsigned)ch;
+         }
+
+         else
+         {
+            if (this_chunk > 0)
+            {
+               if (this_chunk <= 0xffffffU)
+                  error("chunk name too short");
+
+               if (n_chunks >= CHUNK_COUNT_MAX)
+                  error("too many chunks (check CHUNK_COUNT_MAX)");
+
+               chunks[n_chunks++] = this_chunk;
+               this_chunk = 0;
+            }
+         }
+
+         if (ch < 0)
+            break;
+      }
+
+      /* 22 is the number of chunks currently defined (excluding fRAc), at any
+       * time it should also be in PNG_KNOWN_CHUNK_COUNT, but this run of
+       * chunkhash may be trying to add a chunk so allow bigger numbers.
+       */
+#     ifdef PNG_KNOWN_CHUNK_COUNT
+#        define CHUNK_COUNT_MIN PNG_KNOWN_CHUNK_COUNT
+#     else
+#        define CHUNK_COUNT_MIN 26
+#     endif
+      if (n_chunks < CHUNK_COUNT_MIN)
+         error("too few chunks (expecting at least 26)");
+
+      known_chunk_count = n_chunks;
+   }
+
+   /* Exhaustive search of the hash parameters - in fact this isn't very slow at
+    * all.
+    */
+   {
+      unsigned int i1, c_zero = 0, c_one = 0;
+
+      for (i1=0; i1<NPRIMES; ++i1)
+      {
+         unsigned int i2;
+         unsigned int c[4];
+
+         fprintf(stderr, "TEST: %u\n", primes[i1]);
+         c[0] = primes[i1];
+
+         for (i2=0; i2<NPRIMES; ++i2)
+         {
+            unsigned int i3;
+
+            c[1] = primes[i2];
+
+            for (i3=0; i3<NPRIMES; ++i3)
+            {
+               unsigned int i4;
+
+               c[2] = primes[i3];
+
+               for (i4=0; i4<NPRIMES; ++i4)
+               {
+                  unsigned int i;
+                  png_uint_32 hash_mask = 0xffU;
+                  png_uint_32 hashes[CHUNK_COUNT_MAX];
+
+                  c[3] = primes[i4];
+
+                  while (hash_mask > 0xfU)
+                  {
+                     for (i=0; i<known_chunk_count; ++i)
+                     {
+                        unsigned int j;
+                        png_uint_32 hash = test_hash(chunks[i], c, hash_mask);
+
+                        for (j=0; j<i; ++j) if (hashes[j] == hash) goto next_i4;
+
+                        hashes[i] = hash;
+                     }
+
+                     hash_mask >>= 1;
+                  }
+
+               next_i4:
+                  if (hash_mask < 0xffU)
+                  {
+                     /* This worked */
+                     unsigned int best, c0 = 0, c1 = 0;
+
+                     hash_mask <<= 1;
+                     hash_mask += 1;
+
+                     for (i=0; i<4; ++i)
+                     {
+                        if (c[i] == 0)
+                           ++c0;
+
+                        else if (c[i] == 1)
+                           ++c1;
+                     }
+
+                     if (hash_mask == best_mask)
+                        best = (c0 > c_zero) || (c0 == c_zero && c1 > c_one);
+
+                     else
+                        best = (hash_mask < best_mask);
+
+                     if (best)
+                     {
+                        fprintf(stderr, "{%u,%u,%u,%u} & 0x%lx\n",
+                           c[0], c[1], c[2], c[3],
+                           (unsigned long)hash_mask);
+
+                        c_zero = c0;
+                        c_one = c1;
+                        best_mask = hash_mask;
+                        memcpy(best_c, c, sizeof best_c);
+                     }
+                  }
+               } /* i4 */
+            } /* i3 */
+         } /* i2 */
+      } /* i1 */
+   }
+
+   /* Calculate the LUT (png_chunk_hash) */
+   {
+      png_byte b;
+      png_byte lut[256];
+
+      /* A failure returns PNG_KNOWN_CHUNK_COUNT: */
+      memset(lut, known_chunk_count, sizeof lut);
+
+      for (b=0; b<known_chunk_count; ++b)
+         lut[test_hash(chunks[b], best_c, best_mask)] = b;
+
+      /* Validate the pngpriv.h hash function. */
+#     define png_chunk_hash lut
+         {
+            unsigned int i;
+
+            for (i=0; i<known_chunk_count; ++i)
+            {
+               png_uint_32 chunk = chunks[i];
+
+               if (PNG_CHUNK_HASH(chunk) != i)
+                  error("internal error: hash didn't work!");
+            }
+         }
+#     undef lut
+
+      /* Print all the results, first the stuff for pngpriv.h */
+      {
+         unsigned int i = 0;
+
+         while (strings[i] != 0)
+            puts(strings[i++]);
+
+         printf("#define PNG_CHUNK_HASH_MASK 0x%lxU\n",
+            (unsigned long)best_mask);
+         printf("#define PNG_CHUNK_HASH_C0 %u\n", best_c[0]);
+         printf("#define PNG_CHUNK_HASH_C1 %u\n", best_c[1]);
+         printf("#define PNG_CHUNK_HASH_C2 %u\n", best_c[2]);
+         printf("#define PNG_CHUNK_HASH_C3 %u\n", best_c[3]);
+
+         /* Print the hash codes of all the chunks */
+         putchar('\n');
+         print_chunks(chunks, known_chunk_count, 0, 0xffffffff, best_c,
+            best_mask, lut);
+         putchar('\n');
+         printf("#define PNG_KNOWN_CHUNK_COUNT %u\n", known_chunk_count);
+
+         while (strings[++i] != 0)
+            puts(strings[i]);
+
+         /* Now print the LUT */
+         fputs("   ", stdout);
+         {
+            unsigned int j;
+
+            for (j=0; j<=best_mask; ++j)
+            {
+               printf("%d", lut[j]);
+
+               if ((j % 16) == 15 && j < best_mask)
+                  printf(",\n   ");
+
+               else if (j < best_mask)
+                  printf(", ");
+
+               else
+                  printf("\n");
+            }
+         }
+
+         /* And the trailing text */
+         while (strings[++i] != 0)
+            puts(strings[i]);
+      }
+   }
+
+   exit(0);
+}

contrib/tools/chunkhash.h

@@ -0,0 +1,97 @@
+/* chunkhash.h -- a perfect hash code for the chunk names in png.h
+ *
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ *
+ * THIS IS A MACHINE GENERATED FILE.  See contrib/tools/chunkhash.c for
+ * copyright and other information.
+ *
+ * USAGE:  To include the PNG_CHUNK_HASH macro and associated definitions:
+ *
+ * #define PNG_CHUNKHASH_DEFS
+ * #include "contrib/tools/chunkhash.h"
+ *
+ * To define the png_chunk_hash array used by the macro:
+ *
+ * #define PNG_CHUNKHASH_CODE
+ * #include "contrib/tools/chunkhash.h"
+ *
+ * One or both of the defines must be given except when building chunkhash
+ * itself.
+ */
+#ifdef PNG_CHUNKHASH_DEFS
+#ifndef PNG_CHUNKHASH_H
+#define PNG_CHUNKHASH_H
+/* A perfect hash code - returns a value 0..(PNG_KNOWN_CHUNK_COUNT-1) and is
+ * generated by the ridiculously simple program in contrib/tools/chunkhash.c
+ *
+ * The hash code used here multiplies each byte by a different constant to
+ * return a single number:
+ *
+ *    b0 * c[0] + b1 * [c1] + b2 * c[2] + b3 * c[3]
+ *
+ * The values of the constants are found by search using the a table of
+ * primes, including 0, and may be (in fact are at present) 0 for some of the
+ * bytes, the compiler is expected to optimize multiply by zero, or one!
+ *
+ * The lookup table reduces the sparse result of the hash calculation to the
+ * correct index values.  The chunks are indexed in the string order of the
+ * png_uint_32 chunk names.
+ */
+#define PNG_CHUNK_HASH_MASK 0x3fU
+#define PNG_CHUNK_HASH_C0 103
+#define PNG_CHUNK_HASH_C1 1
+#define PNG_CHUNK_HASH_C2 0
+#define PNG_CHUNK_HASH_C3 1
+
+#define PNG_CHUNK_IDAT_TAG 0
+#define PNG_CHUNK_IEND_TAG 1
+#define PNG_CHUNK_IHDR_TAG 2
+#define PNG_CHUNK_PLTE_TAG 3
+#define PNG_CHUNK_bKGD_TAG 4
+#define PNG_CHUNK_cHRM_TAG 5
+#define PNG_CHUNK_fRAc_TAG 6
+#define PNG_CHUNK_gAMA_TAG 7
+#define PNG_CHUNK_gIFg_TAG 8
+#define PNG_CHUNK_gIFt_TAG 9
+#define PNG_CHUNK_gIFx_TAG 10
+#define PNG_CHUNK_hIST_TAG 11
+#define PNG_CHUNK_iCCP_TAG 12
+#define PNG_CHUNK_iTXt_TAG 13
+#define PNG_CHUNK_oFFs_TAG 14
+#define PNG_CHUNK_pCAL_TAG 15
+#define PNG_CHUNK_pHYs_TAG 16
+#define PNG_CHUNK_sBIT_TAG 17
+#define PNG_CHUNK_sCAL_TAG 18
+#define PNG_CHUNK_sPLT_TAG 19
+#define PNG_CHUNK_sRGB_TAG 20
+#define PNG_CHUNK_sTER_TAG 21
+#define PNG_CHUNK_tEXt_TAG 22
+#define PNG_CHUNK_tIME_TAG 23
+#define PNG_CHUNK_tRNS_TAG 24
+#define PNG_CHUNK_zTXt_TAG 25
+
+#define PNG_KNOWN_CHUNK_COUNT 26
+
+extern const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1];
+#endif /* !PNG_CHUNKHASH_H */
+#endif /* PNG_CHUNKHASH_DEFS */
+
+#ifndef PNG_CHUNK_HASH
+#define PNG_CHUNK_HASH(chunk) (png_chunk_hash[PNG_CHUNK_HASH_MASK & (\
+      ((chunk) >> 24) * PNG_CHUNK_HASH_C0 +\
+      ((chunk) >> 16) * PNG_CHUNK_HASH_C1 +\
+      ((chunk) >>  8) * PNG_CHUNK_HASH_C2 +\
+      ((chunk)      ) * PNG_CHUNK_HASH_C3)])
+#endif
+
+#ifdef PNG_CHUNKHASH_CODE
+#ifndef PNG_CHUNKHASH_C
+#define PNG_CHUNKHASH_C
+const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1] = {
+   26, 3, 26, 26, 26, 26, 26, 13, 26, 26, 26, 16, 26, 26, 26, 26,
+   26, 24, 12, 26, 18, 26, 26, 26, 26, 20, 26, 17, 26, 26, 25, 15,
+   26, 8, 14, 26, 26, 22, 26, 26, 1, 19, 5, 21, 26, 26, 9, 26,
+   26, 26, 10, 7, 26, 11, 26, 0, 26, 2, 23, 26, 26, 4, 26, 6
+};
+#endif /* !PNG_CHUNKHASH_C */
+#endif /* PNG_CHUNKHASH_CODE */

contrib/tools/png-fix-itxt.c

@@ -0,0 +1,153 @@
+
+/* png-fix-itxt version 1.0.0
+ *
+ * Copyright 2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.3 [(PENDING RELEASE)]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Usage:            
+ *
+ *     png-fix-itxt.exe < bad.png > good.png
+ *
+ * Fixes a PNG file written with libpng-1.6.0 or 1.6.1 that has one or more
+ * uncompressed iTXt chunks.  Assumes that the actual length is greater
+ * than or equal to the value in the length byte, and that the CRC is
+ * correct for the actual length.  This program hunts for the CRC and
+ * adjusts the length byte accordingly.  It is not an error to process a
+ * PNG file that has no iTXt chunks or one that has valid iTXt chunks;
+ * such files will simply be copied.
+ *
+ * Requires zlib (for crc32 and Z_NULL); build with
+ *
+ *     gcc -O -o png-fix-itxt png-fix-itxt.c -lz
+ *
+ * If you need to handle iTXt chunks larger than 500000 kbytes you must
+ * rebuild png-fix-itxt with a larger values of MAX_LENGTH (or a smaller value
+ * if you know you will never encounter such huge iTXt chunks).
+ */
+
+#include <stdio.h>
+#include <zlib.h>
+
+#define MAX_LENGTH 500000
+
+#define GETBREAK ((unsigned char)(inchar=getchar())); if (inchar == EOF) break
+
+int
+main(void)
+{
+   unsigned int i;
+   unsigned char buf[MAX_LENGTH];
+   unsigned long crc;
+   unsigned char c;
+   int inchar;
+
+/* Skip 8-byte signature */
+   for (i=8; i; i--)
+   {
+      c=GETBREAK;
+      putchar(c);
+   }
+
+if (inchar != EOF)
+for (;;)
+ {
+   /* Read the length */
+   unsigned long length; /* must be 32 bits! */
+   c=GETBREAK; buf[0] = c; length  = c; length <<= 8;
+   c=GETBREAK; buf[1] = c; length += c; length <<= 8;
+   c=GETBREAK; buf[2] = c; length += c; length <<= 8;
+   c=GETBREAK; buf[3] = c; length += c;
+
+   /* Read the chunkname */
+   c=GETBREAK; buf[4] = c;
+   c=GETBREAK; buf[5] = c;
+   c=GETBREAK; buf[6] = c;
+   c=GETBREAK; buf[7] = c;
+
+
+   /* The iTXt chunk type expressed as integers is (105, 84, 88, 116) */
+   if (buf[4] == 105 && buf[5] == 84 && buf[6] == 88 && buf[7] == 116)
+   {
+      if (length >= MAX_LENGTH-12)
+         break;  /* To do: handle this more gracefully */
+
+      /* Initialize the CRC */
+      crc = crc32(0, Z_NULL, 0);
+
+      /* Copy the data bytes */
+      for (i=8; i < length + 12; i++)
+      {
+         c=GETBREAK; buf[i] = c;
+      }
+
+      /* Calculate the CRC */
+      crc = crc32(crc, buf+4, (uInt)length+4);
+
+      for (;;)
+      {
+        /* Check the CRC */
+        if (((crc >> 24) & 0xff) == buf[length+8] &&
+            ((crc >> 16) & 0xff) == buf[length+9] &&
+            ((crc >>  8) & 0xff) == buf[length+10] &&
+            ((crc      ) & 0xff) == buf[length+11])
+           break;
+
+        length++;
+
+        if (length >= MAX_LENGTH-12)
+           break;
+
+        c=GETBREAK;
+        buf[length+11]=c;
+
+        /* Update the CRC */
+        crc = crc32(crc, buf+7+length, 1);
+      }
+
+      /* Update length bytes */
+      buf[0] = (unsigned char)((length << 24) & 0xff);
+      buf[1] = (unsigned char)((length << 16) & 0xff);
+      buf[2] = (unsigned char)((length <<  8) & 0xff);
+      buf[3] = (unsigned char)((length      ) & 0xff);
+
+      /* Write the fixed iTXt chunk (length, name, data, crc) */
+      for (i=0; i<length+12; i++)
+         putchar(buf[i]);
+   }
+
+   else
+   {
+      /* Copy bytes that were already read (length and chunk name) */
+      for (i=0; i<8; i++)
+         putchar(buf[i]);
+
+      /* Copy data bytes and CRC */
+      for (i=8; i< length+12; i++)
+      {
+         c=GETBREAK;
+         putchar(c);
+      }
+
+      if (inchar == EOF)
+      {
+         break;
+      }
+
+   /* The IEND chunk type expressed as integers is (73, 69, 78, 68) */
+      if (buf[4] == 73 && buf[5] == 69 && buf[6] == 78 && buf[7] == 68)
+         break;
+   }
+
+   if (inchar == EOF)
+      break;
+
+   if (buf[4] == 73 && buf[5] == 69 && buf[6] == 78 && buf[7] == 68)
+     break;
+ }
+
+ return 0;
+}

contrib/tools/scale.c

@@ -0,0 +1,238 @@
+/* Given a target range and a source range work out an expression to scale from
+ * the source to the target of the form:
+ *
+ *    (number * mult + add)>>16
+ *
+ * The command arguments are:
+ *
+ *    scale target source
+ *
+ * and the program works out a pair of numbers, mult and add, that evaluate:
+ *
+ *          number * target
+ *   round( --------------- )
+ *              source
+ *
+ * exactly for number in the range 0..source
+ */
+#define _ISOC99_SOURCE 1
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <math.h>
+
+static double minerr;
+static unsigned long minmult, minadd, minshift;
+static long mindelta;
+
+static int
+test(unsigned long target, unsigned long source, unsigned long mult,
+   long add, unsigned long shift, long delta)
+{
+   unsigned long i;
+   double maxerr = 0;
+   double rs = (double)target/source;
+
+   for (i=0; i<=source; ++i)
+   {
+      unsigned long t = i*mult+add;
+      double err = fabs((t >> shift) - i*rs);
+
+      if (err > minerr)
+         return 0;
+
+      if (err > maxerr)
+         maxerr = err;
+   }
+
+   if (maxerr < minerr)
+   {
+      minerr = maxerr;
+      minmult = mult;
+      minadd = add;
+      minshift = shift;
+      mindelta = delta;
+   }
+
+   return maxerr < .5;
+}
+
+static int
+dotest(unsigned long target, unsigned long source, unsigned long mult,
+   long add, unsigned long shift, long delta, int print)
+{
+   if (test(target, source, mult, add, shift, delta))
+   {
+      if (print & 4)
+         printf("      {%11lu,%6ld /* >>%lu */ }, /* %lu/%lu */\n",
+            mult, add, shift, target, source);
+
+      else if (print & 2)
+         printf("      {%11lu,%6ld,%3lu }, /* %lu/%lu */\n",
+            mult, add, shift, target, source);
+
+      else if (print)
+         printf("number * %lu/%lu = (number * %lu + %ld) >> %lu [delta %ld]\n",
+            target, source, mult, add, shift, delta);
+
+      return 1;
+   }
+
+   return 0;
+}
+
+static int
+find(unsigned long target, unsigned long source, int print, int fixshift)
+{
+   unsigned long shift = 0;
+   unsigned long shiftlim = 0;
+
+   /* In the final math the sum is at most (source*mult+add) >> shift, so:
+    *
+    *    source*mult+add < 1<<32
+    *    mult < (1<<32)/source
+    *
+    * but:
+    *
+    *    mult = (target<<shift)/source
+    *
+    * so:
+    *
+    *    (target<<shift) < (1<<32)
+    */
+   if (fixshift < 0)
+      while ((target<<shiftlim) < 0x80000000U) ++shiftlim;
+
+   else
+      shift = shiftlim = (unsigned long)fixshift;
+
+   minerr = 1E8;
+
+   for (; shift<=shiftlim; ++shift)
+   {
+      unsigned long mult = ((target<<shift) + (source>>1)) / source;
+      long delta;
+      long limit = 1; /* seems to be sufficient */
+      long add, start, end;
+
+      end = 1<<shift;
+      start = -end;
+
+      for (add=start; add<=end; ++add)
+         if (dotest(target,source,mult,add,shift,0,print))
+            return 1;
+
+      for (delta=1; delta<=limit; ++delta)
+      {
+#        if 0
+            fprintf(stderr, "%lu/%lu: shift %lu, delta %lu\n", target, source,
+               shift, delta);
+#        endif
+
+         for (add=start; add<=end; ++add)
+         {
+            if (dotest(target, source, mult-delta, add, shift, -delta, print))
+               return 1;
+
+            if (dotest(target, source, mult+delta, add, shift, delta, print))
+               return 1;
+         }
+      }
+   }
+
+   if (print & 4)
+      printf("      {%11lu,%6ld /* >>%lu */ }, /* %lu/%lu ERROR: .5+%g*/\n",
+         minmult, minadd, minshift, target, source, minerr-.5);
+
+   else if (print & 2)
+      printf("      {%11lu,%6ld,%3lu }, /* %lu/%lu ERROR: .5+%g*/\n",
+         minmult, minadd, minshift, target, source, minerr-.5);
+
+   else if (print)
+      printf(
+         "number * %lu/%lu ~= (number * %lu + %ld) >> %lu +/-.5+%g [delta %ld]\n",
+         target, source, minmult, minadd, minshift, minerr-.5, mindelta);
+
+   return 0;
+}
+
+static void
+usage(const char *prog)
+{
+   fprintf(stderr,
+      "usage: %s {--denominator|--maxshift|--code} target {source}\n"
+      " For each 'source' prints 'mult' and 'add' such that:\n\n"
+      "   (number * mult + add) >> 16 = round(number*target/source)\n\n"
+      " for all integer values of number in the range 0..source.\n\n"
+      " --denominator: swap target and source (specify a single source first\n"
+      "                and follow with multiple targets.)\n"
+      "    --maxshift: find the lowest shift value that works for all the\n"
+      "                repeated 'source' values\n"
+      "        --code: output C code for array/structure initialization\n",
+      prog);
+   exit(1);
+}
+
+int
+main(int argc, const char **argv)
+{
+   int i, err = 0, maxshift = 0, firstsrc = 1, code = 0, denominator = 0;
+   unsigned long target, shift = 0;
+
+   while (argc > 1)
+   {
+      if (strcmp(argv[firstsrc], "--maxshift") == 0)
+      {
+         maxshift = 1;
+         ++firstsrc;
+      }
+
+      else if (strcmp(argv[firstsrc], "--code") == 0)
+      {
+         code = 1;
+         ++firstsrc;
+      }
+
+      else if (strcmp(argv[firstsrc], "--denominator") == 0)
+      {
+         denominator = 1;
+         ++firstsrc;
+      }
+
+      else
+         break;
+   }
+
+
+   if (argc < 2+firstsrc)
+      usage(argv[0]);
+
+   target = strtoul(argv[firstsrc++], 0, 0);
+   if (target == 0) usage(argv[0]);
+
+   for (i=firstsrc; i<argc; ++i)
+   {
+      unsigned long source = strtoul(argv[i], 0, 0);
+
+      if (source == 0) usage(argv[0]);
+
+      if (!find(denominator ? source : target, denominator ? target : source,
+         maxshift ? 0 : 1+code, -1))
+         err = 1;
+
+      if (minshift > shift) shift = minshift;
+   }
+
+   if (maxshift) for (i=firstsrc; i<argc; ++i)
+   {
+      unsigned long source = strtoul(argv[i], 0, 0);
+
+      if (!find(denominator ? source : target, denominator ? target : source,
+         code ? 4 : 1, shift))
+         err = 1;
+   }
+
+   /* Just an exit code - the printout above lists the problem */
+   return err;
+}

example.c

@@ -2,8 +2,8 @@
 #if 0 /* in case someone actually tries to compile this */
 
 /* example.c - an example of using libpng
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Maintained 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.3 [(PENDING RELEASE)]
+ * Maintained 1998-2013 Glenn Randers-Pehrson
  * Maintained 1996, 1997 Andreas Dilger)
  * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  * To the extent possible under law, the authors have waived
@@ -39,7 +39,7 @@
 #include <string.h>
 #include <stdio.h>
 #include <png.h>
-#include <zlib.h>
+#include PNG_ZLIB_HEADER /* this is the header libpng was built with */
 
 int main(int argc, const char **argv)
 {
@@ -48,7 +48,8 @@ int main(int argc, const char **argv)
       png_image image; /* The control structure used by libpng */
 
       /* Initialize the 'png_image' structure. */
-      memset(&image, 0, sizeof image);
+      memset(&image, 0, (sizeof image));
+      image.version = PNG_IMAGE_VERSION;
 
       /* The first argument is the file to read: */
       if (png_image_begin_read_from_file(&image, argv[1]))
@@ -75,16 +76,28 @@ int main(int argc, const char **argv)
           * be supplied or the output buffer would have to be initialized to the
           * actual background of the image.
           *
-          * The final argument to png_image_finish_read is the 'row_stride' -
+          * The fourth argument to png_image_finish_read is the 'row_stride' -
           * this is the number of components allocated for the image in each
           * row.  It has to be at least as big as the value returned by
           * PNG_IMAGE_ROW_STRIDE, but if you just allocate space for the
           * default, minimum, size using PNG_IMAGE_SIZE as above you can pass
           * zero.
+          *
+          * The final argument is a pointer to a buffer for the colormap;
+          * colormaps have exactly the same format as a row of image pixels (so
+          * you choose what format to make the colormap by setting
+          * image.format).  A colormap is only returned if
+          * PNG_FORMAT_FLAG_COLORMAP is also set in image.format, so in this
+          * case NULL is passed as the final argument.  If you do want to force
+          * all images into an index/color-mapped format then you can use:
+          *
+          *    PNG_IMAGE_COLORMAP_SIZE(image)
+          *
+          * to find the maximum size of the colormap in bytes.
           */
          if (buffer != NULL &&
             png_image_finish_read(&image, NULL/*background*/, buffer,
-               0/*row_stride*/))
+               0/*row_stride*/, NULL/*colormap*/))
          {
             /* Now write the image out to the second argument.  In the write
              * call 'convert_to_8bit' allows 16-bit data to be squashed down to
@@ -92,7 +105,7 @@ int main(int argc, const char **argv)
              * to the 8-bit format.
              */
             if (png_image_write_to_file(&image, argv[2], 0/*convert_to_8bit*/,
-               buffer, 0/*row_stride*/))
+               buffer, 0/*row_stride*/, NULL/*colormap*/))
             {
                /* The image has been written successfully. */
                exit(0);
@@ -428,9 +441,9 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    /* If we don't have another value */
    else
    {
-      screen_gamma = 2.2;  /* A good guess for a PC monitor in a dimly
-                              lit room */
-      screen_gamma = 1.7 or 1.0;  /* A good guess for Mac systems */
+      screen_gamma = PNG_DEFAULT_sRGB;  /* A good guess for a PC monitor
+                                           in a dimly lit room */
+      screen_gamma = PNG_GAMMA_MAC_18 or 1.0; /* Good guesses for Mac systems */
    }
 
    /* Tell libpng to handle the gamma conversion for you.  The final call
@@ -442,7 +455,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    int intent;
 
    if (png_get_sRGB(png_ptr, info_ptr, &intent))
-      png_set_gamma(png_ptr, screen_gamma, 0.45455);
+      png_set_gamma(png_ptr, screen_gamma, PNG_DEFAULT_sRGB);
    else
    {
       double image_gamma;
@@ -833,7 +846,7 @@ void write_png(char *file_name /* , ... other image information ... */)
 
    /* Set the palette if there is one.  REQUIRED for indexed-color images */
    palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
-             * png_sizeof(png_color));
+             * (sizeof (png_color)));
    /* ... Set palette colors ... */
    png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
    /* You must not free palette here, because png_set_PLTE only makes a link to
@@ -968,12 +981,16 @@ void write_png(char *file_name /* , ... other image information ... */)
     * use the first method if you aren't handling interlacing yourself.
     */
    png_uint_32 k, height, width;
-   png_byte image[height][width*bytes_per_pixel];
+
+   /* In this example, "image" is a one-dimensional array of bytes */
+   png_byte image[height*width*bytes_per_pixel];
+
    png_bytep row_pointers[height];
 
-   if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+   if (height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
      png_error (png_ptr, "Image is too tall to process in memory");
 
+   /* Set up pointers into your "image" byte array */
    for (k = 0; k < height; k++)
      row_pointers[k] = image + k*width*bytes_per_pixel;
 

libpng-manual.txt

@@ -1,9 +1,9 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.0beta24 - June 7, 2012
+ libpng version 1.7.0beta24 - December 15, 2013
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
- Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ Copyright (c) 1998-2013 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
  For conditions of distribution and use, see the disclaimer
@@ -11,9 +11,9 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.0beta24 - June 7, 2012
+ libpng versions 0.97, January 1998, through 1.7.0beta24 - December 15, 2013
  Updated and distributed by Glenn Randers-Pehrson
- Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ Copyright (c) 1998-2013 Glenn Randers-Pehrson
 
  libpng 1.0 beta 6  version 0.96 May 28, 1997
  Updated and distributed by Andreas Dilger
@@ -42,17 +42,16 @@ libpng-manual.txt - A description on how to use and modify libpng
     X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
    XI. Changes to Libpng from version 1.4.x to 1.5.x
   XII. Changes to Libpng from version 1.5.x to 1.6.x
- XIII. Detecting libpng
-  XIV. Source code repository
-   XV. Coding style
-  XVI. Y2K Compliance in libpng
+ XIII. Changes to Libpng from version 1.6.x to 1.7.x
+  XIV. Detecting libpng
+   XV. Source code repository
+  XVI. Coding style
+ XVII. Y2K Compliance in libpng
 
 I. Introduction
 
 This file describes how to use and modify the PNG reference library
-(known as libpng) for your own use.  There are five sections to this
-file: introduction, structures, reading, writing, and modification and
-configuration notes for various special platforms.  In addition to this
+(known as libpng) for your own use.  In addition to this
 file, example.c is a good starting point for using the library, as
 it is heavily commented and should include everything most people
 will need.  We assume that libpng is already installed; see the
@@ -67,7 +66,7 @@ of reducing the amount of time and effort it takes to support the PNG
 file format in application programs.
 
 The PNG specification (second edition), November 2003, is available as
-a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
+a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at
 <http://www.w3.org/TR/2003/REC-PNG-20031110/
 The W3C and ISO documents have identical technical content.
 
@@ -160,8 +159,8 @@ APIs.  Most of these are fairly obvious; for example types corresponding
 to integers of particular sizes and types for passing color values.
 
 One exception is how non-integral numbers are handled.  For application
-convenience most APIs that take such numbers have C (double) arguments,
-however internally PNG, and libpng, use 32 bit signed integers and encode
+convenience most APIs that take such numbers have C (double) arguments;
+however, internally PNG, and libpng, use 32 bit signed integers and encode
 the value by multiplying by 100,000.  As of libpng 1.5.0 a convenience
 macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point)
 which is simply (png_int_32).
@@ -431,7 +430,7 @@ If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
 errors will result in a call to PNG_ABORT() which defaults to abort().
 
-You can #define PNG_ABORT() to a function that does something
+You can #define PNG_ABORT to a function or other C code that does something
 more useful than abort(), as long as your function does not
 return.
 
@@ -526,10 +525,15 @@ you can retrieve with
 
     png_get_user_chunk_ptr(png_ptr);
 
-If you call the png_set_read_user_chunk_fn() function, then all unknown
-chunks will be saved when read, in case your callback function will need
-one or more of them.  This behavior can be changed with the
-png_set_keep_unknown_chunks() function, described below.
+If you call the png_set_read_user_chunk_fn() function, then all unknown chunks
+will be passed to your callback when read.  You can cause known chunks to be
+passed in as well by using png_set_keep_unknown_chunks (see below) - this will
+prevent the normal libpng handling of those known chunks.
+
+If your callback returns 0 the default unknown handling will be used (see
+below).  This is new behavior in libpng 1.7, prior to 1.7 it was not possible to
+discard a chunk; PNG_HANDLE_CHUNK_IF_SAFE was forced.  Libpng 1.6.0 issues a
+warning when this was done.
 
 At this point, you can set up a callback function that will be
 called after each row has been read, which you can use to control
@@ -572,6 +576,7 @@ chunk types. To change this, you can call:
 
     png_set_keep_unknown_chunks(png_ptr, keep,
         chunk_list, num_chunks);
+
     keep       - 0: default unknown chunk handling
                  1: ignore; do not keep
                  2: keep only if safe-to-copy
@@ -585,11 +590,16 @@ chunk types. To change this, you can call:
 
     chunk_list - list of chunks affected (a byte string,
                  five bytes per chunk, NULL or '\0' if
-                 num_chunks is 0)
+                 num_chunks is positive; ignored if
+                 numchunks <= 0).
 
     num_chunks - number of chunks affected; if 0, all
-                 unknown chunks are affected.  If nonzero,
-                 only the chunks in the list are affected
+                 unknown chunks are affected.  If positive,
+                 only the chunks in the list are affected,
+                 and if negative all unknown chunks and
+                 all known chunks except for the IHDR,
+                 PLTE, tRNS, IDAT, and IEND chunks are
+                 affected.
 
 Unknown chunks declared in this way will be saved as raw data onto a
 list of png_unknown_chunk structures.  If a chunk that is normally
@@ -630,7 +640,7 @@ callback function:
 
       /* also ignore unused known chunks: */
       png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks,
-         (int)sizeof(unused_chunks)/5);
+         (int)(sizeof unused_chunks)/5);
     #endif
 
 User limits
@@ -669,9 +679,6 @@ where 0x7fffffffL means unlimited.  You can retrieve this limit with
 
    chunk_cache_max = png_get_chunk_cache_max(png_ptr);
 
-This limit also applies to the number of buffers that can be allocated
-by png_decompress_chunk() while decompressing iTXt, zTXt, and iCCP chunks.
-
 You can also set a limit on the amount of memory that a compressed chunk
 other than IDAT can occupy, with
 
@@ -732,7 +739,7 @@ situations:
                      encoding.
 
 You would use the linear (unencoded) value if you need to process the pixel
-values further because this avoids the need to decode and reencode each
+values further because this avoids the need to decode and re-encode each
 component value whenever arithmetic is performed.  A lot of graphics software
 uses linear values for this reason, often with higher precision component values
 to preserve overall accuracy.
@@ -985,7 +992,7 @@ where row_pointers is an array of pointers to the pixel data for each row:
 If you know your image size and pixel size ahead of time, you can allocate
 row_pointers prior to calling png_read_png() with
 
-   if (height > PNG_UINT_32_MAX/png_sizeof(png_byte))
+   if (height > PNG_UINT_32_MAX/(sizeof (png_byte))
       png_error (png_ptr,
           "Image is too tall to process in memory");
 
@@ -994,7 +1001,7 @@ row_pointers prior to calling png_read_png() with
           "Image is too wide to process in memory");
 
    row_pointers = png_malloc(png_ptr,
-       height*png_sizeof(png_bytep));
+       height*(sizeof (png_bytep)));
 
    for (int i=0; i<height, i++)
       row_pointers[i]=NULL;  /* security precaution */
@@ -1773,7 +1780,7 @@ the current display (e.g., the background color from a web page).  You
 need to tell libpng how the color is represented, both the format of the
 component values in the color (the number of bits) and the gamma encoding of the
 color.  The function takes two arguments, background_gamma_mode and need_expand
-to convey this information, however only two combinations are likely to be
+to convey this information; however, only two combinations are likely to be
 useful:
 
     png_color_16 my_background;
@@ -2067,7 +2074,7 @@ the second parameter NULL.
 
 If you don't want libpng to handle the interlacing details, just call
 png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images.
-Each of the images is a valid image by itself, however you will almost
+Each of the images is a valid image by itself; however, you will almost
 certainly need to distribute the pixels from each sub-image to the
 correct place.  This is where everything gets very tricky.
 
@@ -2224,7 +2231,7 @@ sPLT, only the n'th item in the structure is freed, where n is "seq".
 The default behavior is only to free data that was allocated internally
 by libpng.  This can be changed, so that libpng will not free the data,
 or so that it will free data that was allocated by the user with png_malloc()
-or png_zalloc() and passed in via a png_set_*() function, with
+or png_calloc() and passed in via a png_set_*() function, with
 
     png_data_freer(png_ptr, info_ptr, freer, mask)
 
@@ -2245,7 +2252,7 @@ or png_destroy_*() is supposed to free the data.  When the user assumes
 responsibility for libpng-allocated data, the application must use
 png_free() to free it, and when the user transfers responsibility to libpng
 for data that the user has allocated, the user must have used png_malloc()
-or png_zalloc() to allocate it.
+or png_calloc() to allocate it.
 
 If you allocated your row_pointers in a single block, as suggested above in
 the description of the high level read interface, you must not transfer
@@ -2281,7 +2288,7 @@ For a more compact example of reading a PNG image, see the file example.c.
 
 Reading PNG files progressively
 
-The progressive reader is slightly different then the non-progressive
+The progressive reader is slightly different from the non-progressive
 reader.  Instead of calling png_read_info(), png_read_rows(), and
 png_read_end(), you make one call to png_process_data(), which calls
 callbacks when it has the info, a row, or the end of the image.  You
@@ -2555,12 +2562,26 @@ section below for more information on the libpng error handling.
 
 If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
-errors will result in a call to PNG_ABORT() which defaults to abort().
+errors will result in a call to PNG_ABORT which defaults to abort().
 
-You can #define PNG_ABORT() to a function that does something
+You can #define PNG_ABORT to a function or other C code that does something
 more useful than abort(), as long as your function does not
 return.
 
+Checking for invalid palette index on write was added at libpng
+1.5.10.  If a pixel contains an invalid (out-of-range) index libpng issues
+a benign error.  This is enabled by default because this condition is an
+error according to the PNG specification, Clause 11.3.2, but the error can
+be ignored in each png_ptr with
+
+   png_set_check_for_invalid_index(png_ptr, 0);
+
+If the error is ignored, or if png_benign_error() treats it as a warning,
+any invalid pixels are written as-is by the encoder, resulting in an
+invalid PNG datastream as output.  In this case the application is
+responsible for ensuring that the pixel indexes are in range when it writes
+a PLTE chunk with fewer entries than the bit depth would allow.
+
 Now you need to set up the output code.  The default for libpng is to
 use the C function fwrite().  If you use this, you will need to pass a
 valid FILE * in the function png_init_io().  Be sure that the file is
@@ -3063,18 +3084,53 @@ tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
 although this isn't a requirement.  Unlike the tIME chunk, the
 "Creation Time" tEXt chunk is not expected to be automatically changed
 by the software.  To facilitate the use of RFC 1123 dates, a function
-png_convert_to_rfc1123(png_timep) is provided to convert from PNG
-time to an RFC 1123 format string.
+png_convert_to_rfc1123_buffer(png_ptr, buffer, png_timep) is provided to
+convert from PNG time to an RFC 1123 format string.  The caller must provide
+a writeable buffer of at least 29 bytes.
 
 Writing unknown chunks
 
-You can use the png_set_unknown_chunks function to queue up chunks
-for writing.  You give it a chunk name, raw data, and a size; that's
-all there is to it.  The chunks will be written by the next following
-png_write_info_before_PLTE, png_write_info, or png_write_end function.
-Any chunks previously read into the info structure's unknown-chunk
-list will also be written out in a sequence that satisfies the PNG
-specification's ordering rules.
+You can use the png_set_unknown_chunks function to queue up private chunks
+for writing.  You give it a chunk name, location, raw data, and a size.  You
+also must use png_set_keep_unknown_chunks() to ensure that libpng will
+handle them.  That's all there is to it.  The chunks will be written by the
+next following png_write_info_before_PLTE, png_write_info, or png_write_end
+function, depending upon the specified location.  Any chunks previously
+read into the info structure's unknown-chunk list will also be written out
+in a sequence that satisfies the PNG specification's ordering rules.
+
+Here is an example of writing two private chunks, prVt and miNE:
+
+    #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+    /* Set unknown chunk data */
+    png_unknown_chunk unk_chunk[2];
+    strcpy((char *) unk_chunk[0].name, "prVt";
+    unk_chunk[0].data = (unsigned char *) "PRIVATE DATA";
+    unk_chunk[0].size = strlen(unk_chunk[0].data)+1;
+    unk_chunk[0].location = PNG_HAVE_IHDR;
+    strcpy((char *) unk_chunk[1].name, "miNE";
+    unk_chunk[1].data = (unsigned char *) "MY CHUNK DATA";
+    unk_chunk[1].size = strlen(unk_chunk[0].data)+1;
+    unk_chunk[1].location = PNG_AFTER_IDAT;
+    png_set_unknown_chunks(write_ptr, write_info_ptr,
+        unk_chunk, 2);
+    /* Needed because miNE is not safe-to-copy */
+    png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS,
+       (png_bytep) "miNE", 1);
+    # if PNG_LIBPNG_VER < 10600
+      /* Deal with unknown chunk location bug in 1.5.x and earlier */
+      png_set_unknown_chunk_location(png, info, 0, PNG_HAVE_IHDR);
+      png_set_unknown_chunk_location(png, info, 1, PNG_AFTER_IDAT);
+    # endif
+    # if PNG_LIBPNG_VER < 10500
+      /* PNG_AFTER_IDAT writes two copies of the chunk prior to libpng-1.5.0,
+       * one before IDAT and another after IDAT, so don't use it; only use
+       * PNG_HAVE_IHDR location.  This call resets the location previously
+       * set by assignment and png_set_unknown_chunk_location() for chunk 1.
+       */
+      png_set_unknown_chunk_location(png, info, 1, PNG_HAVE_IHDR);
+    # endif
+    #endif
 
 The high-level write interface
 
@@ -3426,7 +3482,7 @@ png_destroy_write_struct().
 The default behavior is only to free data that was allocated internally
 by libpng.  This can be changed, so that libpng will not free the data,
 or so that it will free data that was allocated by the user with png_malloc()
-or png_zalloc() and passed in via a png_set_*() function, with
+or png_calloc() and passed in via a png_set_*() function, with
 
     png_data_freer(png_ptr, info_ptr, freer, mask)
 
@@ -3462,7 +3518,7 @@ When the user assumes responsibility for libpng-allocated data, the
 application must use
 png_free() to free it, and when the user transfers responsibility to libpng
 for data that the user has allocated, the user must have used png_malloc()
-or png_zalloc() to allocate it.
+or png_calloc() to allocate it.
 
 If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
 separately, do not transfer responsibility for freeing text_ptr to libpng,
@@ -3478,7 +3534,7 @@ The simplified API, which became available in libpng-1.6.0, hides the details
 of both libpng and the PNG file format itself.
 It allows PNG files to be read into a very limited number of
 in-memory bitmap formats or to be written from the same formats.  If these
-formats do not accomodate your needs then you can, and should, use the more
+formats do not accommodate your needs then you can, and should, use the more
 sophisticated APIs above - these support a wide variety of in-memory formats
 and a wide variety of sophisticated transformations to those formats as well
 as a wide variety of APIs to manipulate ancilliary information.
@@ -3517,16 +3573,17 @@ png_image is a structure that describes the in-memory format of an image
 when it is being read or define the in-memory format of an image that you
 need to write.  The "png_image" structure contains the following members:
 
+   png_uint_32  version Set to PNG_IMAGE_VERSION
    png_uint_32  width   Image width in pixels (columns)
    png_uint_32  height  Image height in pixels (rows)
    png_uint_32  format  Image format as defined below
    png_uint_32  flags   A bit mask containing informational flags
    png_controlp opaque  Initialize to NULL, free with png_image_free
-   png_const_bytep colormap A pointer to the application color-map
+   png_uint_32  colormap_entries; Number of entries in the color-map
    png_uint_32  warning_or_error;
    char         message[64];
 
-In the event of an error or warning the following field wrning_or_error
+In the event of an error or warning the following field warning_or_error
 field will be set to a non-zero value and the 'message' field will contain
 a '\0' terminated string with the libpng error or warning message.  If both
 warnings and an error were encountered, only the error is recorded.  If there
@@ -3682,6 +3739,22 @@ First the information about the samples.
    a fixed number determined by the format so can easily be allocated on the
    stack if necessary.
 
+#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
+   (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
+   /* The maximum size of the color-map required by the format expressed in a
+    * count of components.  This can be used to compile-time allocate a
+    * color-map:
+    *
+    * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
+    *
+    * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
+    *
+    * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
+    * information from one of the png_image_begin_read_ APIs and dynamically
+    * allocate the required memory.
+    */
+
+
 Corresponding information about the pixels
 
   PNG_IMAGE_PIXEL_(test,fmt)
@@ -3740,7 +3813,8 @@ READ APIs
       The PNG header is read from the given memory buffer.
 
    int png_image_finish_read(png_imagep image,
-      png_colorp background, void *buffer, png_int_32 row_stride));
+      png_colorp background, void *buffer,
+      png_int_32 row_stride, void *colormap));
 
       Finish reading the image into the supplied buffer and
       clean up the png_image structure.
@@ -3777,6 +3851,7 @@ WRITE APIS
 For write you must initialize a png_image structure to describe the image to
 be written:
 
+   version: must be set to PNG_IMAGE_VERSION
    opaque: must be initialized to NULL
    width: image width in pixels
    height: image height in rows
@@ -3784,15 +3859,17 @@ be written:
    flags: set to 0 unless one of the defined flags applies; set
       PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images
       where the RGB values do not correspond to the colors in sRGB.
+   colormap_entries: set to the number of entries in the color-map (0 to 256)
 
    int png_image_write_to_file, (png_imagep image,
       const char *file, int convert_to_8bit, const void *buffer,
-      png_int_32 row_stride));
+      png_int_32 row_stride, const void *colormap));
 
       Write the image to the named file.
 
    int png_image_write_to_stdio(png_imagep image, FILE *file,
-      int convert_to_8_bit, const void *buffer, png_int_32 row_stride)
+      int convert_to_8_bit, const void *buffer,
+      png_int_32 row_stride, const void *colormap)
 
       Write the image to the given (FILE*).
 
@@ -3826,12 +3903,13 @@ in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively.  To change
 these functions, call the appropriate png_set_*_fn() function.
 
 Memory allocation is done through the functions png_malloc(), png_calloc(),
-and png_free().  These currently just call the standard C functions.
-png_calloc() calls png_malloc() and then clears the newly
-allocated memory to zero.  There is limited support for certain systems
-with segmented memory architectures and the types of pointers declared by
-png.h match this; you will have to use appropriate pointers in your
-application.  Since it is
+and png_free().  The png_malloc() and png_free() functions currently just
+call the standard C functions and png_calloc() calls png_malloc() and then
+clears the newly allocated memory to zero; note that png_calloc(png_ptr, size)
+is not the same as the calloc(number, size) function provided by stdlib.h.
+There is limited support for certain systems with segmented memory
+architectures and the types of pointers declared by png.h match this; you
+will have to use appropriate pointers in your application.  Since it is
 unlikely that the method of handling memory allocation on a platform
 will change between applications, these functions must be modified in
 the library at compile time.  If you prefer to use a different method
@@ -3899,7 +3977,7 @@ Error handling in libpng is done through png_error() and png_warning().
 Errors handled through png_error() are fatal, meaning that png_error()
 should never return to its caller.  Currently, this is handled via
 setjmp() and longjmp() (unless you have compiled libpng with
-PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
+PNG_NO_SETJMP, in which case it is handled via PNG_ABORT),
 but you could change this to do things like exit() if you should wish,
 as long as your function does not return.
 
@@ -3941,6 +4019,18 @@ compiler documentation for more details.  For an alternative approach, you
 may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net),
 which is illustrated in pngvalid.c and in contrib/visupng.
 
+Beginning in libpng-1.4.0, the png_set_benign_errors() API became available.
+You can use this to handle certain errors (normally handled as errors)
+as warnings.
+
+    png_set_benign_errors (png_ptr, int allowed);
+
+    allowed: 0: treat png_benign_error() as an error.
+             1: treat png_benign_error() as a warning.
+
+As of libpng-1.6.0, the default condition is to treat benign errors as
+warnings while reading and as errors while writing.
+
 Custom chunks
 
 If you need to read or write custom chunks, you may need to get deeper
@@ -4061,7 +4151,7 @@ available to set these separately for non-IDAT
 compressed chunks such as zTXt, iTXt, and iCCP:
 
     #include zlib.h
-    #if PNG_LIBPNG_VER <= 10504
+    #if PNG_LIBPNG_VER >= 10504
     png_set_text_compression_level(png_ptr, level);
 
     png_set_text_compression_mem_level(png_ptr, level);
@@ -4211,7 +4301,7 @@ the message, "message" is the formatted string to be printed,
 and p1 and p2 are parameters that are to be embedded in the string
 according to printf-style formatting directives.  For example,
 
-   png_debug1(2, "foo=%d\n", foo);
+   png_debug1(2, "foo=%d", foo);
 
 is expanded to
 
@@ -4509,14 +4599,16 @@ png_set_strip_error_numbers() was removed from the library by default.
 
 The png_zalloc() and png_zfree() functions are no longer exported.
 The png_zalloc() function no longer zeroes out the memory that it
-allocates.
+allocates.  Applications that called png_zalloc(png_ptr, number, size)
+can call png_calloc(png_ptr, number*size) instead, and can call
+png_free() instead of png_zfree().
 
 Support for dithering was disabled by default in libpng-1.4.0, because
 it has not been well tested and doesn't actually "dither".
 The code was not
 removed, however, and could be enabled by building libpng with
 PNG_READ_DITHER_SUPPORTED defined.  In libpng-1.4.2, this support
-was reenabled, but the function was renamed png_set_quantize() to
+was re-enabled, but the function was renamed png_set_quantize() to
 reflect more accurately what it actually does.  At the same time,
 the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to
 PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED
@@ -4529,20 +4621,41 @@ XI.  Changes to Libpng from version 1.4.x to 1.5.x
 From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
 function) incorrectly returned a value of type png_uint_32.
 
-Checking for invalid palette index on read or write was added at libpng
-1.5.10.  When an invalid index is found, libpng issues a benign error.
-This is enabled by default but can be disabled in each png_ptr with
+Checking for invalid palette index on write was added at libpng
+1.5.10.  If a pixel contains an invalid (out-of-range) index libpng issues
+a benign error.  This is enabled by default because this condition is an
+error according to the PNG specification, Clause 11.3.2, but the error can
+be ignored in each png_ptr with
 
    png_set_check_for_invalid_index(png_ptr, allowed);
 
       allowed  - one of
-                 0: disable
-                 1: enable
+                 0: disable benign error (accept the
+                    invalid data without warning).
+                 1: enable benign error (treat the
+                    invalid data as an error or a
+                    warning).
+
+If the error is ignored, or if png_benign_error() treats it as a warning,
+any invalid pixels are decoded as opaque black by the decoder and written
+as-is by the encoder.
+
+Retrieving the maximum palette index found was added at libpng-1.5.15.
+This statement must appear after png_read_png() or png_read_image() while
+reading, and after png_write_png() or png_write_image() while writing.
+
+   int max_palette = png_get_palette_max(png_ptr, info_ptr);
+
+This will return the maximum palette index found in the image, or "-1" if
+the palette was not checked, or "0" if no palette was found.  Note that this
+does not account for any palette index used by ancillary chunks such as the
+bKGD chunk; you must check those separately to determine the maximum
+palette index actually used.
 
 A. Changes that affect users of libpng
 
 There are no substantial API changes between the non-deprecated parts of
-the 1.4.5 API and the 1.5.0 API; however the ability to directly access
+the 1.4.5 API and the 1.5.0 API; however, the ability to directly access
 members of the main libpng control structures, png_struct and png_info,
 deprecated in earlier versions of libpng, has been completely removed from
 libpng 1.5.
@@ -4553,9 +4666,12 @@ need access to information in zlib.h will need to add the '#include "zlib.h"'
 directive.  It does not matter whether this is placed prior to or after
 the '"#include png.h"' directive.
 
-We moved the png_strcpy(), png_strncpy(), png_strlen(), png_memcpy(),
-png_memcmp(), png_sprintf, and png_memcpy() macros into a private
-header file (pngpriv.h) that is not accessible by applications.
+The png_sprintf(), png_strcpy(), and png_strncpy() macros are no longer used
+and were removed.
+
+We moved the png_strlen(), png_memcpy(), png_memset(), and png_memcmp()
+macros into a private header file (pngpriv.h) that is not accessible to
+applications.
 
 In png_get_iCCP, the type of "profile" was changed from png_charpp
 to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep.
@@ -4636,7 +4752,7 @@ did not exist.)
 Applications can now choose whether to use these macros or to call the
 corresponding function by defining PNG_USE_READ_MACROS or
 PNG_NO_USE_READ_MACROS before including png.h.  Notice that this is
-only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0
+only supported from 1.5.0; defining PNG_NO_USE_READ_MACROS prior to 1.5.0
 will lead to a link failure.
 
 Prior to libpng-1.5.4, the zlib compressor used the same set of parameters
@@ -4672,16 +4788,19 @@ limits are now
    png_user_chunk_cache_max  0 (unlimited)   128
    png_user_chunk_malloc_max 0 (unlimited) 8,000,000
 
+The png_set_option() function (and the "options" member of the png struct) was
+added to libpng-1.5.15.
+
 B. Changes to the build and configuration of libpng
 
 Details of internal changes to the library code can be found in the CHANGES
 file and in the GIT repository logs.  These will be of no concern to the vast
-majority of library users or builders, however the few who configure libpng
+majority of library users or builders; however, the few who configure libpng
 to a non-default feature set may need to change how this is done.
 
 There should be no need for library builders to alter build scripts if
 these use the distributed build support - configure or the makefiles -
-however users of the makefiles may care to update their build scripts
+however, users of the makefiles may care to update their build scripts
 to build pnglibconf.h where the corresponding makefile does not do so.
 
 Building libpng with a non-default configuration has changed completely.
@@ -4787,7 +4906,7 @@ merely stops the function from being exported.
 PNG_FLOATING_ARITHMETIC_SUPPORTED chooses between the internal floating
 point implementation or the fixed point one.  Typically the fixed point
 implementation is larger and slower than the floating point implementation
-on a system that supports floating point, however it may be faster on a
+on a system that supports floating point; however, it may be faster on a
 system which lacks floating point hardware and therefore uses a software
 emulation.
 
@@ -4816,7 +4935,7 @@ pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the
 build of pnglibconf.h and it is never included in an application build.
 
 The rarely used alternative of adding a list of feature macros to the
-CFLAGS setting in the build also still works, however the macros will be
+CFLAGS setting in the build also still works; however, the macros will be
 copied to pnglibconf.h and this may produce macro redefinition warnings
 when the individual C files are compiled.
 
@@ -4841,31 +4960,150 @@ how to do this, and a case where pngusr.h is still required.
 XII.  Changes to Libpng from version 1.5.x to 1.6.x
 
 A "simplified API" has been added (see documentation in png.h and a simple
-example in contrib/examples/pngtopng.c)
+example in contrib/examples/pngtopng.c).  The new publicly visible API
+includes the following:
+
+   macros:
+     PNG_FORMAT_*
+     PNG_IMAGE_*
+   structures:
+     png_control
+     png_image
+   read functions
+     png_image_begin_read_from_file()
+     png_image_begin_read_from_stdio()
+     png_image_begin_read_from_memory()
+     png_image_finish_read()
+     png_image_free()
+   write functions
+     png_image_write_to_file()
+     png_image_write_to_stdio()
 
 Starting with libpng-1.6.0, you can configure libpng to prefix all exported
-symbols.
+symbols, using the PNG_PREFIX macro.
 
 We no longer include string.h in png.h.  The include statement has been moved
 to pngpriv.h, where it is not accessible by applications.  Applications that
-need access to information in string.h must add an '#include "string.h"'
+need access to information in string.h must add an '#include <string.h>'
 directive.  It does not matter whether this is placed prior to or after
-the '"#include png.h"' directive.
+the '#include "png.h"' directive.
 
 The following API are now DEPRECATED:
    png_info_init_3()
    png_convert_to_rfc1123() which has been replaced
      with png_convert_to_rfc1123_buffer()
+   png_data_freer()
    png_malloc_default()
    png_free_default()
+   png_reset_zstream()
 
-The following has been removed:
+The following have been removed:
    png_get_io_chunk_name(), which has been replaced
      with png_get_io_chunk_type().  The new
      function returns a 32-bit integer instead of
      a string.
+   The png_sizeof(), png_strlen(), png_memcpy(), png_memcmp(), and
+     png_memset() macros are no longer used in the libpng sources and
+     have been removed.  These had already been made invisible to applications
+     (i.e., defined in the private pngpriv.h header file) since libpng-1.5.0.
 
-XIII.  Detecting libpng
+The signatures of many exported functions were changed, such that
+   png_structp became png_structrp or png_const_structrp
+   png_infop became png_inforp or png_const_inforp
+where "rp" indicates a "restricted pointer".
+
+Error detection in some chunks has improved; in particular the iCCP chunk
+reader now does pretty complete validation of the basic format.  Some bad
+profiles that were previously accepted are now accepted with a warning or
+rejected, depending upon the png_set_benign_errors() setting, in particular the
+very old broken Microsoft/HP 3144-byte sRGB profile.  The PNG spec requirement
+that only grayscale profiles may appear in images with color type 0 or 4 and
+that even if the image only contains gray pixels, only RGB profiles may appear
+in images with color type 2, 3, or 6, is now enforced.  The sRGB chunk
+is allowed to appear in images with any color type.
+
+Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
+an empty language field or an empty translated keyword.  Both of these
+are allowed by the PNG specification, so these warnings are no longer issued.
+
+The library now issues an error if the application attempts to set a
+transform after it calls png_read_update_info() or if it attempts to call
+both png_read_update_info() and png_start_read_image() or to call either
+of them more than once.
+
+The default condition for benign_errors is now to treat benign errors as
+warnings while reading and as errors while writing.
+
+The library now issues a warning if both background processing and RGB to
+gray are used when gamma correction happens. As with previous versions of
+the library the results are numerically very incorrect in this case.
+
+There are some minor arithmetic changes in some transforms such as
+png_set_background(), that might be detected by certain regression tests.
+
+Unknown chunk handling has been improved internally, without any API change.
+This adds more correct option control of the unknown handling, corrects
+a pre-existing bug where the per-chunk 'keep' setting is ignored, and makes
+it possible to skip IDAT chunks in the sequential reader.
+
+The machine-generated configure files are no longer included in branches
+libpng16 and later of the GIT repository.  They continue to be included
+in the tarball releases, however.
+
+Libpng-1.6.0 through 1.6.2 used the CMF bytes at the beginning of the IDAT
+stream to set the size of the sliding window for reading instead of using the
+default 32-kbyte sliding window size.  It was discovered that there are
+hundreds of PNG files in the wild that have incorrect CMF bytes that caused
+libpng to issue a "too far back" error and reject the file.  Libpng-1.6.3 and
+later calculate their own safe CMF from the image dimensions, provide a way
+to revert to the libpng-1.5.x behavior (ignoring the CMF bytes and using a
+32-kbyte sliding window), by using
+
+    png_set_option(png_ptr, PNG_MAXIMUM_INFLATE_WINDOW,
+        PNG_OPTION_ON);
+
+and provide a tool (contrib/tools/pngfix) for optimizing the CMF bytes
+correctly.
+
+Libpng-1.6.0 and libpng-1.6.1 wrote uncompressed iTXt chunks with the wrong
+length, which resulted in PNG files that cannot be read beyond the bad iTXt
+chunk.  This error was fixed in libpng-1.6.3, and a tool (called
+contrib/tools/png-fix-itxt) has been added to the libpng distribution.
+
+XIII.  Changes to Libpng from version 1.6.x to 1.7.x
+
+Some functions that were deprecated in libpng-1.6.0 were removed:
+    png_reset_zstream(),
+    png_info_init_3(),
+    png_data_freer() and its associated flags,
+    png_malloc_default(),
+    and png_free_default().
+
+The PNG_ABORT() macro was changed to PNG_ABORT, and the default is now
+"abort()" for all platforms (previously it was "ExitProcess(0)" on
+Windows platforms).  Starting with libpng-1.7.0 you have to define
+PNG_ABORT instead of PNG_ABORT(), and you must include a terminating
+semicolon in your definition, e.g.,
+
+    #if PNGCRUSH_LIBPNG_VER >= 10700
+    #  ifdef _WINDOWS_
+    #    define PNG_ABORT ExitProcess(0);
+    #  else
+    #    define PNG_ABORT abort();
+    #  endif
+    #else
+    #  ifdef _WINDOWS_
+    #    define PNG_ABORT() ExitProcess(0)
+    #  else
+    #    define PNG_ABORT() abort()
+    #  endif
+    #endif
+
+The 8-bit compose and rgb_to_grayscale operations were made more accurate.
+While these did not introduce API incompatibility, there may be differences
+in unit test results.
+
+XIV.  Detecting libpng
 
 The png_get_io_ptr() function has been present since libpng-0.88, has never
 changed, and is unaffected by conditional compilation macros.  It is the
@@ -4881,11 +5119,11 @@ control.  The git repository was built from old libpng-x.y.z.tar.gz files
 going back to version 0.70.  You can access the git repository (read only)
 at
 
-    git://libpng.git.sourceforge.net/gitroot/libpng
+    git://git.code.sf.net/p/libpng/code
 
-or you can browse it via "gitweb" at
+or you can browse it with a web browser by selecting the "code" button at
 
-    http://libpng.git.sourceforge.net/git/gitweb.cgi?p=libpng
+    https://sourceforge.net/projects/libpng
 
 Patches can be sent to glennrp at users.sourceforge.net or to
 png-mng-implement at lists.sourceforge.net or you can upload them to
@@ -4898,7 +5136,7 @@ simple verbal discriptions of bug fixes, reported either to the
 SourceForge bug tracker, to the png-mng-implement at lists.sf.net
 mailing list, or directly to glennrp.
 
-XV. Coding style
+XVI. Coding style
 
 Our coding style is similar to the "Allman" style, with curly
 braces on separate lines:
@@ -4981,10 +5219,21 @@ pngtest) appear in
 pngpriv.h
 above the comment that says
 
-  /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+  /* Maintainer: Put new private prototypes here ^ */
+
+We put a space after the "sizeof" operator and we omit the
+optional parentheses around its argument when the argument
+is an expression, not a type name, and we always enclose the
+sizeof operator, with its argument, in parentheses:
+
+  (sizeof (png_uint_32))
+  (sizeof array)
+
+Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as
+though it were a function.
 
 To avoid polluting the global namespace, the names of all exported
-functions and variables begin with  "png_", and all publicly visible C
+functions and variables begin with "png_", and all publicly visible C
 preprocessor macros begin with "PNG".  We request that applications that
 use libpng *not* begin any of their own symbols with either of these strings.
 
@@ -4998,39 +5247,43 @@ left parenthesis that follows it:
     for (i = 2; i > 0; --i)
        y[i] = a(x) + (int)b;
 
-We prefer #ifdef and #ifndef to #if defined() and if !defined()
-when there is only one macro being tested.
+We prefer #ifdef and #ifndef to #if defined() and #if !defined()
+when there is only one macro being tested.  We always use parentheses
+with "defined".
 
 We prefer to express integers that are used as bit masks in hex format,
 with an even number of lower-case hex digits (e.g., 0x00, 0xff, 0x0100).
 
+We prefer to use underscores in variable names rather than camelCase, except
+for a few type names that we inherit from zlib.h.
+
 We do not use the TAB character for indentation in the C sources.
 
 Lines do not exceed 80 characters.
 
 Other rules can be inferred by inspecting the libpng source.
 
-XVI. Y2K Compliance in libpng
+XVII. Y2K Compliance in libpng
 
-June 7, 2012
+December 15, 2013
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.0beta24 are Y2K compliant.  It is my belief that earlier
+upward through 1.7.0beta24 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
-Libpng only has three year fields.  One is a 2-byte unsigned integer that
-will hold years up to 65535.  The other two hold the date in text
-format, and will hold years up to 9999.
+Libpng only has two year fields.  One is a 2-byte unsigned integer
+that will hold years up to 65535.  The other, which is deprecated,
+holds the date in text format, and will hold years up to 9999.
 
 The integer is
     "png_uint_16 year" in png_time_struct.
 
-The strings are
-    "png_charp time_buffer" in png_struct and
-    "near_time_buffer", which is a local character string in png.c.
+The string is
+    "char time_buffer[29]" in png_struct.  This is no longer used
+in libpng-1.6.x and will be removed from libpng-1.7.0.
 
 There are seven time-related functions:
 

libpngpf.3

@@ -1,21 +1,11 @@
-.TH LIBPNGPF 3 "June 7, 2012"
+.TH LIBPNGPF 3 "December 15, 2013"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.0beta24
+libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta24
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
 
-\fI\fB
-
-\fBAs of libpng version \fP\fI1.5.1\fP\fB, this section is no longer \fP\fImaintained\fP\fB, now \fIthat
-
-\fBthe private function prototypes are hidden in pngpriv.h and not \fIaccessible
-
-\fBto applications. Look in pngpriv.h for the prototypes and a short \fIdescription
-
-\fBof each \fIfunction.
-
-\fI\fB
+\fBAs of libpng version \fP\fI1.5.1\fP\fB, this section is no longer \fP\fImaintained\fP\fB, now that the private function prototypes are hidden in pngpriv.h and not accessible to applications. Look in pngpriv.h for the prototypes and a short description of each \fIfunction.
 
 .SH DESCRIPTION
 The functions previously listed here are used privately by libpng and are not

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "June 7, 2012"
+.TH PNG 5 "December 15, 2013"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
@@ -24,6 +24,7 @@ PNG specification (second edition), November 2003:
 .IP
 .br
   <http://www.w3.org/TR/2003/REC-PNG-20031110/
+.LP
 PNG 1.2 specification, July 1999:
 .IP
 .br
@@ -58,7 +59,7 @@ Thomas Boutell and others (png-list).
 
 .SH COPYRIGHT NOTICE
 .LP
-This man page is Copyright (c) 1998-2006 Glenn Randers-Pehrson.  See png.h
+This man page is Copyright (c) 1998-2012 Glenn Randers-Pehrson.  See png.h
 for conditions of use and distribution.
 .LP
 The PNG Specification (Second Edition) is

pngconf.h

@@ -1,9 +1,9 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.0beta24 - June 7, 2012
+ * libpng version 1.7.0beta24 - December 15, 2013
  *
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -198,18 +198,16 @@
  * ==========================
  * This code is used at build time to find PNG_IMPEXP, the API settings
  * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
- * import processing is possible.  On Windows/x86 systems it also sets
+ * import processing is possible.  On Windows systems it also sets
  * compiler-specific macros to the values required to change the calling
  * conventions of the various functions.
  */
-#if ( defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
-      defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) ) &&\
-    ( defined(_X86_) || defined(_X64_) || defined(_M_IX86) ||\
-      defined(_M_X64) || defined(_M_IA64) )
-  /* Windows system (DOS doesn't support DLLs) running on x86/x64.  Includes
-   * builds under Cygwin or MinGW.  Also includes Watcom builds but these need
-   * special treatment because they are not compatible with GCC or Visual C
-   * because of different calling conventions.
+#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
+    defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
+  /* Windows system (DOS doesn't support DLLs).  Includes builds under Cygwin or
+   * MinGW on any architecture currently supported by Windows.  Also includes
+   * Watcom builds but these need special treatment because they are not
+   * compatible with GCC or Visual C because of different calling conventions.
    */
 #  if PNG_API_RULE == 2
     /* If this line results in an error, either because __watcall is not
@@ -220,9 +218,12 @@
 #    define PNGCAPI __watcall
 #  endif
 
-#  if defined(__GNUC__) || (defined (_MSC_VER) && (_MSC_VER >= 800))
+#  if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
 #    define PNGCAPI __cdecl
 #    if PNG_API_RULE == 1
+       /* If this line results in an error __stdcall is not understood and
+        * PNG_API_RULE should not have been set to '1'.
+        */
 #      define PNGAPI __stdcall
 #    endif
 #  else
@@ -260,7 +261,7 @@
 #    endif
 #  endif /* compiler */
 
-#else /* !Windows/x86 */
+#else /* !Windows */
 #  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
 #    define PNGAPI _System
 #  else /* !Windows/x86 && !OS/2 */
@@ -366,24 +367,28 @@
 #    ifndef PNG_NORETURN
 #      define PNG_NORETURN   __attribute__((__noreturn__))
 #    endif
-#    ifndef PNG_ALLOCATED
-#      define PNG_ALLOCATED  __attribute__((__malloc__))
-#    endif
-#    ifndef PNG_DEPRECATED
-#      define PNG_DEPRECATED __attribute__((__deprecated__))
-#    endif
-#    ifndef PNG_PRIVATE
-#      if 0 /* Doesn't work so we use deprecated instead*/
-#        define PNG_PRIVATE \
-          __attribute__((warning("This function is not exported by libpng.")))
-#      else
-#        define PNG_PRIVATE \
-          __attribute__((__deprecated__))
+#    if __GNUC__ >= 3
+#      ifndef PNG_ALLOCATED
+#        define PNG_ALLOCATED  __attribute__((__malloc__))
 #      endif
-#    endif
-#    ifndef PNG_RESTRICT
-#      define PNG_RESTRICT __restrict
-#    endif
+#      ifndef PNG_DEPRECATED
+#        define PNG_DEPRECATED __attribute__((__deprecated__))
+#      endif
+#      ifndef PNG_PRIVATE
+#        if 0 /* Doesn't work so we use deprecated instead*/
+#          define PNG_PRIVATE \
+            __attribute__((warning("This function is not exported by libpng.")))
+#        else
+#          define PNG_PRIVATE \
+            __attribute__((__deprecated__))
+#        endif
+#      endif
+#      if ((__GNUC__ != 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
+#        ifndef PNG_RESTRICT
+#          define PNG_RESTRICT __restrict
+#        endif
+#      endif /*  __GNUC__ == 3.0 */
+#    endif /*  __GNUC__ >= 3 */
 
 #  elif defined(_MSC_VER)  && (_MSC_VER >= 1300)
 #    ifndef PNG_USE_RESULT
@@ -431,6 +436,9 @@
 #ifndef PNG_PRIVATE
 #  define PNG_PRIVATE     /* This is a private libpng function */
 #endif
+#ifndef PNG_RESTRICT
+#  define PNG_RESTRICT    /* The C99 "restrict" feature */
+#endif
 #ifndef PNG_FP_EXPORT     /* A floating point API. */
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 #     define PNG_FP_EXPORT(ordinal, type, name, args)\
@@ -503,6 +511,8 @@
 
 /* Prior to 1.6.0 it was possible to disable the use of size_t, 1.6.0, however,
  * requires an ISOC90 compiler and relies on consistent behavior of sizeof.
+ *
+ * DEPRECATED: don't use these types, instead use size_t and ptrdiff_t.
  */
 typedef size_t png_size_t;
 typedef ptrdiff_t png_ptrdiff_t;
@@ -523,13 +533,13 @@ typedef ptrdiff_t png_ptrdiff_t;
 #  endif
 #endif
 
-/* png_alloc_size_t is guaranteed to be no smaller than png_size_t, and no
- * smaller than png_uint_32.  Casts from png_size_t or png_uint_32 to
+/* png_alloc_size_t is guaranteed to be no smaller than size_t, and no
+ * smaller than png_uint_32.  Casts from size_t or png_uint_32 to
  * png_alloc_size_t are not necessary; in fact, it is recommended not to use
  * them at all so that the compiler can complain when something turns out to be
  * problematic.
  *
- * Casts in the other direction (from png_alloc_size_t to png_size_t or
+ * Casts in the other direction (from png_alloc_size_t to size_t or
  * png_uint_32) should be explicitly applied; however, we do not expect to
  * encounter practical situations that require such conversions.
  *
@@ -539,15 +549,9 @@ typedef ptrdiff_t png_ptrdiff_t;
 #ifdef PNG_SMALL_SIZE_T
    typedef png_uint_32 png_alloc_size_t;
 #else
-   typedef png_size_t png_alloc_size_t;
+   typedef size_t png_alloc_size_t;
 #endif
 
-/* This macro makes the sizeof operator look and behave like a function, except
- * that it can take a type without the enclosing () as an argument so long as
- * the type contains no "," characters.
- */
-#define png_sizeof(x) (sizeof (x))
-
 /* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
  * implementations of Intel CPU specific support of user-mode segmented address
  * spaces, where 16-bit pointers address more than 65536 bytes of memory using
@@ -581,8 +585,8 @@ typedef char                  * png_charp;
 typedef const char            * png_const_charp;
 typedef png_fixed_point       * png_fixed_point_p;
 typedef const png_fixed_point * png_const_fixed_point_p;
-typedef png_size_t            * png_size_tp;
-typedef const png_size_t      * png_const_size_tp;
+typedef size_t                * png_size_tp;
+typedef const size_t          * png_const_size_tp;
 
 #ifdef PNG_STDIO_SUPPORTED
 typedef FILE            * png_FILE_p;

pngdebug.h

@@ -1,11 +1,11 @@
 
 /* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
  *
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
+ * Last changed in libpng 1.5.18 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -25,7 +25,7 @@
  *   (actually ((void)0)).
  *
  *   level: level of detail of message, starting at 0.  A level 'n'
- *          message is preceded by 'n' tab characters (not implemented
+ *          message is preceded by 'n' 3-space indentations (not implemented
  *          on Microsoft compilers unless PNG_DEBUG_FILE is also
  *          defined, to allow debug DLL compilation with no standard IO).
  *   message: a printf(3) style text string.  A trailing '\n' is added
@@ -77,32 +77,29 @@
 #      endif /* PNG_DEBUG_FILE */
 
 #      if (PNG_DEBUG > 1)
-/* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on
- * non-ISO compilers
- */
 #        ifdef __STDC__
 #          ifndef png_debug
 #            define png_debug(l,m) \
        do { \
        int num_tabs=l; \
-       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
-         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : "")))); \
        } while (0)
 #          endif
 #          ifndef png_debug1
 #            define png_debug1(l,m,p1) \
        do { \
        int num_tabs=l; \
-       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
-         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1); \
        } while (0)
 #          endif
 #          ifndef png_debug2
 #            define png_debug2(l,m,p1,p2) \
        do { \
        int num_tabs=l; \
-       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
-         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1,p2);\
        } while (0)
 #          endif
 #        else /* __STDC __ */

pngerror.c

@@ -1,8 +1,8 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -80,7 +80,8 @@ png_error,(png_const_structrp png_ptr, png_const_charp error_message),
    }
 #endif
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), error_message);
+      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
+          error_message);
 
    /* If the custom handler doesn't exist, or if it returns,
       use the default handler, which will not return. */
@@ -381,6 +382,10 @@ png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
 #     endif
       png_error(png_ptr, error_message);
    }
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 
 void /* PRIVATE */
@@ -390,6 +395,10 @@ png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
      png_warning(png_ptr, error_message);
   else
      png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 
 void /* PRIVATE */
@@ -399,6 +408,10 @@ png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
      png_warning(png_ptr, error_message);
   else
      png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 #endif /* BENIGN_ERRORS */
 
@@ -414,8 +427,9 @@ static PNG_CONST char png_digit[16] = {
    'A', 'B', 'C', 'D', 'E', 'F'
 };
 
-#define PNG_MAX_ERROR_TEXT 64
-#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
+#define PNG_MAX_ERROR_TEXT 196 /* Currently limited be profile_error in png.c */
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+   (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
 static void /* PRIVATE */
 png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
     error_message)
@@ -497,19 +511,69 @@ png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 #ifdef PNG_READ_SUPPORTED
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 void PNGAPI
-png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
+png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
+    error_message)
 {
    if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
       png_chunk_warning(png_ptr, error_message);
 
    else
       png_chunk_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 #endif
 #endif /* PNG_READ_SUPPORTED */
 
+void /* PRIVATE */
+png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
+{
+#  ifndef PNG_WARNINGS_SUPPORTED
+      PNG_UNUSED(message)
+#  endif
+
+   /* This is always supported, but for just read or just write it
+    * unconditionally does the right thing.
+    */
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      if (png_ptr->mode & PNG_IS_READ_STRUCT)
+#  endif
+
+#  ifdef PNG_READ_SUPPORTED
+      {
+         if (error < PNG_CHUNK_ERROR)
+            png_chunk_warning(png_ptr, message);
+
+         else
+            png_chunk_benign_error(png_ptr, message);
+      }
+#  endif
+
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      else if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
+#  endif
+
+#  ifdef PNG_WRITE_SUPPORTED
+      {
+         if (error < PNG_CHUNK_WRITE_ERROR)
+            png_app_warning(png_ptr, message);
+
+         else
+            png_app_error(png_ptr, message);
+      }
+#  endif
+}
+
 #ifdef PNG_ERROR_TEXT_SUPPORTED
-#ifdef PNG_FLOATING_POINT_SUPPORTED
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+   (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
+   defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
+   (defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) &&\
+   defined(PNG_sCAL_SUPPORTED))
 PNG_FUNCTION(void,
 png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
 {
@@ -517,7 +581,7 @@ png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
 #  define fixed_message_ln ((sizeof fixed_message)-1)
    int  iin;
    char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
-   png_memcpy(msg, fixed_message, fixed_message_ln);
+   memcpy(msg, fixed_message, fixed_message_ln);
    iin = 0;
    if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
    {
@@ -555,7 +619,7 @@ png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
    {
       png_ptr->jmp_buf_size = 0; /* not allocated */
 
-      if (jmp_buf_size <= sizeof png_ptr->jmp_buf_local)
+      if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
          png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
 
       else
@@ -576,7 +640,7 @@ png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
 
       if (size == 0)
       {
-         size = sizeof png_ptr->jmp_buf_local;
+         size = (sizeof png_ptr->jmp_buf_local);
          if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
          {
             /* This is an internal error in libpng: somehow we have been left
@@ -703,8 +767,17 @@ png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
       png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
 #endif
 
-   /* Here if not setjmp support or if png_ptr is null. */
-   PNG_ABORT();
+   /* If control reaches this point, png_longjmp() must not return. The only
+    * choice is to terminate the whole process (or maybe the thread); to do
+    * this the ANSI-C abort() function is used unless a different method is 
+    * implemented by overriding the default configuration setting for
+    * PNG_ABORT (see scripts/pnglibconf.dfa).
+    *
+    * API change: prior to 1.7.0 PNG_ABORT was invoked as a function type macro
+    * with no arguments 'PNG_ABORT();', in 1.7.0 this is changed to a simple
+    * macro that is defined in the configuration.
+    */
+   PNG_ABORT
 }
 
 #ifdef PNG_WARNINGS_SUPPORTED
@@ -807,8 +880,8 @@ png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
 }
 #endif
 
-#if defined PNG_SIMPLIFIED_READ_SUPPORTED ||\
-   defined PNG_SIMPLIFIED_WRITE_SUPPORTED
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
    /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
     * possible to implement without setjmp support just so long as there is some
     * way to handle the error return here:
@@ -825,7 +898,7 @@ png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
     */
    if (image != NULL)
    {
-      png_safecat(image->message, sizeof image->message, 0, error_message);
+      png_safecat(image->message, (sizeof image->message), 0, error_message);
       image->warning_or_error |= PNG_IMAGE_ERROR;
 
       /* Retrieve the jmp_buf from within the png_control, making this work for
@@ -837,9 +910,10 @@ png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
 
       /* Missing longjmp buffer, the following is to help debugging: */
       {
-         size_t pos = png_safecat(image->message, sizeof image->message, 0,
+         size_t pos = png_safecat(image->message, (sizeof image->message), 0,
             "bad longjmp: ");
-         png_safecat(image->message, sizeof image->message, pos, error_message);
+         png_safecat(image->message, (sizeof image->message), pos,
+             error_message);
       }
    }
 
@@ -857,16 +931,16 @@ png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
    /* A warning is only logged if there is no prior warning or error. */
    if (image->warning_or_error == 0)
    {
-      png_safecat(image->message, sizeof image->message, 0, warning_message);
+      png_safecat(image->message, (sizeof image->message), 0, warning_message);
       image->warning_or_error |= PNG_IMAGE_WARNING;
    }
 }
 #endif
 
 int /* PRIVATE */
-png_safe_execute(png_imagep imageIn, int (*function)(png_voidp), png_voidp arg)
+png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
 {
-   volatile png_imagep image = imageIn;
+   volatile png_imagep image = image_in;
    volatile int result;
    volatile png_voidp saved_error_buf;
    jmp_buf safe_jmpbuf;

pngget.c

@@ -1,8 +1,8 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.1 [March 28, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -112,7 +112,8 @@ png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
 }
 
 png_uint_32 PNGAPI
-png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
+png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -129,7 +130,8 @@ png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr
 }
 
 png_uint_32 PNGAPI
-png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
+png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+    info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -164,7 +166,8 @@ png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 float PNGAPI
-png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp info_ptr)
+png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
 {
 #ifdef PNG_READ_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -175,6 +178,9 @@ png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp info_ptr
          return ((float)((float)info_ptr->y_pixels_per_unit
              /(float)info_ptr->x_pixels_per_unit));
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return ((float)0.0);
@@ -203,6 +209,9 @@ png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
           (png_int_32)info_ptr->x_pixels_per_unit))
          return res;
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return 0;
@@ -422,6 +431,7 @@ png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #endif  /* PNG_EASY_ACCESS_SUPPORTED */
 
+
 png_byte PNGAPI
 png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
@@ -431,6 +441,7 @@ png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
    return (0);
 }
 
+#ifdef PNG_READ_SUPPORTED
 png_const_bytep PNGAPI
 png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
@@ -439,6 +450,7 @@ png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
 
    return (NULL);
 }
+#endif
 
 #ifdef PNG_bKGD_SUPPORTED
 png_uint_32 PNGAPI
@@ -522,32 +534,32 @@ png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
       png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
 
       if (red_X != NULL)
-         *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.redX,
+         *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
             "cHRM red X");
       if (red_Y != NULL)
-         *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.redY,
+         *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y,
             "cHRM red Y");
       if (red_Z != NULL)
-         *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.redZ,
+         *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
             "cHRM red Z");
       if (green_X != NULL)
          *green_X = png_float(png_ptr,
-            info_ptr->colorspace.end_points_XYZ.greenX, "cHRM green X");
+            info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X");
       if (green_Y != NULL)
          *green_Y = png_float(png_ptr,
-            info_ptr->colorspace.end_points_XYZ.greenY, "cHRM green Y");
+            info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y");
       if (green_Z != NULL)
          *green_Z = png_float(png_ptr,
-            info_ptr->colorspace.end_points_XYZ.greenZ, "cHRM green Z");
+            info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z");
       if (blue_X != NULL)
-         *blue_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.blueX,
-            "cHRM blue X");
+         *blue_X = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X");
       if (blue_Y != NULL)
-         *blue_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.blueY,
-            "cHRM blue Y");
+         *blue_Y = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y");
       if (blue_Z != NULL)
-         *blue_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.blueZ,
-            "cHRM blue Z");
+         *blue_Z = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z");
       return (PNG_INFO_cHRM);
    }
 
@@ -570,23 +582,23 @@ png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
       png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
 
       if (int_red_X != NULL)
-         *int_red_X = info_ptr->colorspace.end_points_XYZ.redX;
+         *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X;
       if (int_red_Y != NULL)
-         *int_red_Y = info_ptr->colorspace.end_points_XYZ.redY;
+         *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y;
       if (int_red_Z != NULL)
-         *int_red_Z = info_ptr->colorspace.end_points_XYZ.redZ;
+         *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z;
       if (int_green_X != NULL)
-         *int_green_X = info_ptr->colorspace.end_points_XYZ.greenX;
+         *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X;
       if (int_green_Y != NULL)
-         *int_green_Y = info_ptr->colorspace.end_points_XYZ.greenY;
+         *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y;
       if (int_green_Z != NULL)
-         *int_green_Z = info_ptr->colorspace.end_points_XYZ.greenZ;
+         *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z;
       if (int_blue_X != NULL)
-         *int_blue_X = info_ptr->colorspace.end_points_XYZ.blueX;
+         *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X;
       if (int_blue_Y != NULL)
-         *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blueY;
+         *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y;
       if (int_blue_Z != NULL)
-         *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blueZ;
+         *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z;
       return (PNG_INFO_cHRM);
    }
 
@@ -689,7 +701,7 @@ png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #ifdef PNG_iCCP_SUPPORTED
 png_uint_32 PNGAPI
-png_get_iCCP(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
     png_charpp name, int *compression_type,
     png_bytepp profile, png_uint_32 *proflen)
 {
@@ -714,14 +726,14 @@ png_get_iCCP(png_const_structrp png_ptr, png_const_inforp info_ptr,
 #endif
 
 #ifdef PNG_sPLT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_sPLT(png_const_structrp png_ptr, png_const_inforp info_ptr,
+int PNGAPI
+png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
     png_sPLT_tpp spalettes)
 {
    if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
    {
       *spalettes = info_ptr->splt_palettes;
-      return ((png_uint_32)info_ptr->splt_palettes_num);
+      return info_ptr->splt_palettes_num;
    }
 
    return (0);
@@ -730,7 +742,7 @@ png_get_sPLT(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #ifdef PNG_hIST_SUPPORTED
 png_uint_32 PNGAPI
-png_get_hIST(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
     png_uint_16p *hist)
 {
    png_debug1(1, "in %s retrieval function", "hIST");
@@ -806,7 +818,7 @@ png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #ifdef PNG_pCAL_SUPPORTED
 png_uint_32 PNGAPI
-png_get_pCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
     png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
     png_charp *units, png_charpp *params)
 {
@@ -831,9 +843,8 @@ png_get_pCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
 #endif
 
 #ifdef PNG_sCAL_SUPPORTED
-#  ifdef PNG_FIXED_POINT_SUPPORTED
-#    if (defined PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
-         (defined PNG_FLOATING_POINT_SUPPORTED)
+#  ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+#     ifdef PNG_FIXED_POINT_SUPPORTED
 png_uint_32 PNGAPI
 png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, png_fixed_point *width, png_fixed_point *height)
@@ -854,9 +865,9 @@ png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
    return(0);
 }
-#    endif /* FLOATING_ARITHMETIC */
-#  endif /* FIXED_POINT */
-#  ifdef PNG_FLOATING_POINT_SUPPORTED
+#     endif /* FIXED_POINT */
+
+#     ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32 PNGAPI
 png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, double *width, double *height)
@@ -872,7 +883,9 @@ png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
    return(0);
 }
-#  endif /* FLOATING POINT */
+#     endif /* FLOATING POINT */
+#  endif /* FLOATING_ARITHMETIC */
+
 png_uint_32 PNGAPI
 png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, png_charpp width, png_charpp height)
@@ -926,7 +939,7 @@ png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
 #endif /* pHYs */
 
 png_uint_32 PNGAPI
-png_get_PLTE(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr,
     png_colorp *palette, int *num_palette)
 {
    png_debug1(1, "in %s retrieval function", "PLTE");
@@ -962,8 +975,8 @@ png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
 #endif
 
 #ifdef PNG_TEXT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_text(png_const_structrp png_ptr, png_const_inforp info_ptr,
+int PNGAPI
+png_get_text(png_const_structrp png_ptr, png_inforp info_ptr,
     png_textp *text_ptr, int *num_text)
 {
    if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
@@ -977,7 +990,7 @@ png_get_text(png_const_structrp png_ptr, png_const_inforp info_ptr,
       if (num_text != NULL)
          *num_text = info_ptr->num_text;
 
-      return ((png_uint_32)info_ptr->num_text);
+      return info_ptr->num_text;
    }
 
    if (num_text != NULL)
@@ -1050,9 +1063,9 @@ png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
 }
 #endif
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 int PNGAPI
-png_get_unknown_chunks(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr,
     png_unknown_chunkpp unknowns)
 {
    if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
@@ -1149,4 +1162,17 @@ png_get_io_chunk_type (png_const_structrp png_ptr)
 }
 #endif /* ?PNG_IO_STATE_SUPPORTED */
 
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+int PNGAPI
+png_get_palette_max(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return png_ptr->num_palette_max;
+
+   return (-1);
+}
+#  endif
+#endif
+
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */

pnginfo.h

@@ -55,7 +55,7 @@
 
 struct png_info_def
 {
-   /* the following are necessary for every PNG file */
+   /* The following are necessary for every PNG file */
    png_uint_32 width;  /* width of image in pixels (from IHDR) */
    png_uint_32 height; /* height of image in pixels (from IHDR) */
    png_uint_32 valid;  /* valid chunk data (see PNG_INFO_ below) */
@@ -70,11 +70,15 @@ struct png_info_def
    png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
    png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
 
-#ifdef PNG_READ_SUPPORTED
-   /* The following is informational only on read, and not used on writes. */
+   /* The following are set by png_set_IHDR, called from the application on
+    * write, but the are never actually used by the write code.
+    */
    png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
    png_byte pixel_depth;    /* number of bits per pixel */
    png_byte spare_byte;     /* to align the data, and for future use */
+
+#ifdef PNG_READ_SUPPORTED
+   /* This is never set during write */
    png_byte signature[8];   /* magic bytes read by libpng from start of file */
 #endif
 
@@ -84,7 +88,7 @@ struct png_info_def
     * and initialize the appropriate fields below.
     */
 
-#if defined PNG_COLORSPACE_SUPPORTED || defined PNG_GAMMA_SUPPORTED
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
    /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are
     * defined.  When COLORSPACE is switched on all the colorspace-defining
     * chunks should be enabled, when GAMMA is switched on all the gamma-defining
@@ -216,17 +220,16 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
 /* New members added in libpng-1.0.6 */
    png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
 
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
- defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
    /* Storage for unknown chunks that the library doesn't recognize. */
    png_unknown_chunkp unknown_chunks;
-   int unknown_chunks_num;
+   int                unknown_chunks_num;
 #endif
 
 #ifdef PNG_sPLT_SUPPORTED
    /* Data on sPLT chunks (there may be more than one). */
    png_sPLT_tp splt_palettes;
-   png_uint_32 splt_palettes_num;
+   int         splt_palettes_num;
 #endif
 
 #ifdef PNG_sCAL_SUPPORTED

pngmem.c

@@ -1,8 +1,8 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -30,7 +30,7 @@ png_destroy_png_struct(png_structrp png_ptr)
        * png_get_mem_ptr, so fake a temporary png_struct to support this.
        */
       png_struct dummy_struct = *png_ptr;
-      memset(png_ptr, 0, sizeof *png_ptr);
+      memset(png_ptr, 0, (sizeof *png_ptr));
       png_free(&dummy_struct, png_ptr);
 
 #     ifdef PNG_SETJMP_SUPPORTED
@@ -54,7 +54,7 @@ png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
    ret = png_malloc(png_ptr, size);
 
    if (ret != NULL)
-      png_memset(ret, 0, size);
+      memset(ret, 0, size);
 
    return ret;
 }
@@ -73,10 +73,11 @@ png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
     * to implement a user memory handler.  This checks to be sure it isn't
     * called with big numbers.
     */
-#ifdef PNG_USER_MEM_SUPPORTED
+#ifndef PNG_USER_MEM_SUPPORTED
    PNG_UNUSED(png_ptr)
 #endif
-   if (size > 0 && size <= ~(size_t)0
+
+   if (size > 0 && size <= PNG_SIZE_MAX
 #     ifdef PNG_MAX_MALLOC_64K
          && size <= 65536U
 #     endif
@@ -95,6 +96,80 @@ png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
       return NULL;
 }
 
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
+/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
+ * that arises because of the checks in png_realloc_array that are repeated in
+ * png_malloc_array.
+ */
+static png_voidp
+png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
+   size_t element_size)
+{
+   png_alloc_size_t req = nelements; /* known to be > 0 */
+
+   if (req <= PNG_SIZE_MAX/element_size)
+      return png_malloc_base(png_ptr, req * element_size);
+
+   /* The failure case when the request is too large */
+   return NULL;
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_array,(png_const_structrp png_ptr, int nelements,
+   size_t element_size),PNG_ALLOCATED)
+{
+   if (nelements <= 0 || element_size == 0)
+      png_error(png_ptr, "internal error: array alloc");
+
+   return png_malloc_array_checked(png_ptr, nelements, element_size);
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_realloc_array,(png_structrp png_ptr, png_const_voidp old_array,
+   int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
+{
+   /* These are internal errors: */
+   if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
+      (old_array == NULL && old_elements > 0))
+      png_error(png_ptr, "internal error: array realloc");
+
+   /* Check for overflow on the elements count (so the caller does not have to
+    * check.)
+    */
+   if (add_elements <= INT_MAX - old_elements)
+   {
+      png_voidp new_array = png_malloc_array_checked(png_ptr,
+         old_elements+add_elements, element_size);
+
+      if (new_array != NULL)
+      {
+         /* Because png_malloc_array worked the size calculations below cannot
+          * overflow.
+          */
+         if (old_elements > 0)
+            memcpy(new_array, old_array, element_size*(unsigned)old_elements);
+
+         memset((char*)new_array + element_size*(unsigned)old_elements, 0,
+            element_size*(unsigned)add_elements);
+
+         return new_array;
+      }
+   }
+
+#ifdef PNG_READ_SUPPORTED
+# ifdef PNG_USER_LIMITS_SUPPORTED
+   /* The potential overflow case.  Set the cache counter so libpng will
+    * not make any more attempts
+    */
+   png_ptr->user_chunk_cache_max = 2;
+# endif
+#endif
+
+   return NULL; /* error */
+}
+#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */
+
 /* Various functions that have different error handling are derived from this.
  * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
  * function png_malloc_default is also provided.
@@ -110,31 +185,11 @@ png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
    ret = png_malloc_base(png_ptr, size);
 
    if (ret == NULL)
-       png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
+       png_error(png_ptr, "Out of memory");
 
    return ret;
 }
 
-#ifdef PNG_USER_MEM_SUPPORTED
-PNG_FUNCTION(png_voidp,PNGAPI
-png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
-   PNG_ALLOCATED PNG_DEPRECATED)
-{
-   png_voidp ret;
-
-   if (png_ptr == NULL)
-      return NULL;
-
-   /* Passing 'NULL' here bypasses the application provided memory handler. */
-   ret = png_malloc_base(NULL/*use malloc*/, size);
-
-   if (ret == NULL)
-      png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
-
-   return ret;
-}
-#endif /* PNG_USER_MEM_SUPPORTED */
-
 /* This function was added at libpng version 1.2.3.  The png_malloc_warn()
  * function will issue a png_warning and return NULL instead of issuing a
  * png_error, if it fails to allocate the requested memory.
@@ -170,17 +225,8 @@ png_free(png_const_structrp png_ptr, png_voidp ptr)
       png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
 
    else
-      png_free_default(png_ptr, ptr);
-}
-
-PNG_FUNCTION(void,PNGAPI
-png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
-{
-   if (png_ptr == NULL || ptr == NULL)
-      return;
 #endif /* PNG_USER_MEM_SUPPORTED */
-
-   free(ptr);
+      free(ptr);
 }
 
 #ifdef PNG_USER_MEM_SUPPORTED

pngpread.c

@@ -1,8 +1,8 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -151,7 +151,7 @@ png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
 void /* PRIVATE */
 png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
 {
-   png_size_t num_checked = png_ptr->sig_bytes,
+   png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */ 
              num_to_check = 8 - num_checked;
 
    if (png_ptr->buffer_size < num_to_check)
@@ -185,6 +185,9 @@ void /* PRIVATE */
 png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 {
    png_uint_32 chunk_name;
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   int keep; /* unknown handling method */
+#endif
 
    /* First we make sure we have enough data for the 4 byte chunk name
     * and the 4 byte chunk length before proceeding with decoding the
@@ -216,14 +219,28 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 
    if (chunk_name == png_IDAT)
    {
-      /* This is here above the if/else case statement below because if the
-       * unknown handling marks 'IDAT' as unknown then the IDAT handling case is
-       * completely skipped.
-       *
-       * TODO: there must be a better way of doing this.
-       */
       if (png_ptr->mode & PNG_AFTER_IDAT)
          png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+      /* If we reach an IDAT chunk, this means we have read all of the
+       * header chunks, and we can start reading the image (or if this
+       * is called after the image has been read - we have an error).
+       */
+      if (!(png_ptr->mode & PNG_HAVE_IHDR))
+         png_error(png_ptr, "Missing IHDR before IDAT");
+
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+          !(png_ptr->mode & PNG_HAVE_PLTE))
+         png_error(png_ptr, "Missing PLTE before IDAT");
+
+      png_ptr->mode |= PNG_HAVE_IDAT;
+
+      if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+         if (png_ptr->push_length == 0)
+            return;
+
+      if (png_ptr->mode & PNG_AFTER_IDAT)
+         png_benign_error(png_ptr, "Too many IDATs found[p]");
    }
 
    if (chunk_name == png_IHDR)
@@ -254,8 +271,8 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
       png_push_have_end(png_ptr, info_ptr);
    }
 
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   else if (png_chunk_unknown_handling(png_ptr, chunk_name))
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -263,26 +280,13 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
          return;
       }
 
-      if (chunk_name == png_IDAT)
-         png_ptr->mode |= PNG_HAVE_IDAT;
-
-      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
 
       if (chunk_name == png_PLTE)
          png_ptr->mode |= PNG_HAVE_PLTE;
-
-      else if (chunk_name == png_IDAT)
-      {
-         if (!(png_ptr->mode & PNG_HAVE_IHDR))
-            png_error(png_ptr, "Missing IHDR before IDAT");
-
-         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-             !(png_ptr->mode & PNG_HAVE_PLTE))
-            png_error(png_ptr, "Missing PLTE before IDAT");
-      }
    }
-
 #endif
+
    else if (chunk_name == png_PLTE)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -295,30 +299,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 
    else if (chunk_name == png_IDAT)
    {
-      /* If we reach an IDAT chunk, this means we have read all of the
-       * header chunks, and we can start reading the image (or if this
-       * is called after the image has been read - we have an error).
-       */
-
-      if (!(png_ptr->mode & PNG_HAVE_IHDR))
-         png_error(png_ptr, "Missing IHDR before IDAT");
-
-      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-          !(png_ptr->mode & PNG_HAVE_PLTE))
-         png_error(png_ptr, "Missing PLTE before IDAT");
-
-      if (png_ptr->mode & PNG_HAVE_IDAT)
-      {
-         if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
-            if (png_ptr->push_length == 0)
-               return;
-
-         if (png_ptr->mode & PNG_AFTER_IDAT)
-            png_benign_error(png_ptr, "Too many IDATs found");
-      }
-
       png_ptr->idat_size = png_ptr->push_length;
-      png_ptr->mode |= PNG_HAVE_IDAT;
       png_ptr->process_mode = PNG_READ_IDAT_MODE;
       png_push_have_info(png_ptr, info_ptr);
       png_ptr->zstream.avail_out =
@@ -547,8 +528,8 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 
       png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
-
 #endif
+
    else
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -556,7 +537,8 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
          png_push_save_buffer(png_ptr);
          return;
       }
-      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
+         PNG_HANDLE_CHUNK_AS_DEFAULT);
    }
 
    png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
@@ -649,7 +631,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       else
          save_size = png_ptr->save_buffer_size;
 
-      png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
+      memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
       length -= save_size;
       ptr += save_size;
       png_ptr->buffer_size -= save_size;
@@ -666,7 +648,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       else
          save_size = png_ptr->current_buffer_size;
 
-      png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
+      memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
       png_ptr->buffer_size -= save_size;
       png_ptr->current_buffer_size -= save_size;
       png_ptr->current_buffer_ptr += save_size;
@@ -715,13 +697,13 @@ png_push_save_buffer(png_structrp png_ptr)
          png_error(png_ptr, "Insufficient memory for save_buffer");
       }
 
-      png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+      memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
       png_free(png_ptr, old_buffer);
       png_ptr->save_buffer_max = new_max;
    }
    if (png_ptr->current_buffer_size)
    {
-      png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
+      memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
          png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
       png_ptr->save_buffer_size += png_ptr->current_buffer_size;
       png_ptr->current_buffer_size = 0;
@@ -976,7 +958,7 @@ png_push_process_row(png_structrp png_ptr)
     * it may not be in the future, so this was changed just to copy the
     * interlaced row count:
     */
-   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+   memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
 
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
    if (png_ptr->transformations)
@@ -1210,7 +1192,7 @@ png_read_push_finish_row(png_structrp png_ptr)
    if (png_ptr->interlaced)
    {
       png_ptr->row_number = 0;
-      png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+      memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
 
       do
       {

pngrio.c

@@ -1,8 +1,8 @@
 
 /* pngrio.c - functions for data input
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -102,6 +102,7 @@ png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
    png_ptr->read_data_fn = read_data_fn;
 #endif
 
+#ifdef PNG_WRITE_SUPPORTED
    /* It is an error to write to a read device */
    if (png_ptr->write_data_fn != NULL)
    {
@@ -110,6 +111,7 @@ png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
           "Can't set both read_data_fn and write_data_fn in the"
           " same structure");
    }
+#endif
 
 #ifdef PNG_WRITE_FLUSH_SUPPORTED
    png_ptr->output_flush_fn = NULL;

pngstruct.h

@@ -1,11 +1,11 @@
 
 /* pngstruct.h - header file for PNG reference library
  *
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -28,7 +28,9 @@
    /* We must ensure that zlib uses 'const' in declarations. */
 #  define ZLIB_CONST
 #endif
-#include "zlib.h"
+
+#include PNG_ZLIB_HEADER
+
 #ifdef const
    /* zlib.h sometimes #defines const to nothing, undo this. */
 #  undef const
@@ -48,10 +50,10 @@
 /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
  * can handle at once.  This type need be no larger than 16 bits (so maximum of
  * 65535), this define allows us to discover how big it is, but limited by the
- * maximuum for png_size_t.  The value can be overriden in a library build
- * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
- * lower value (e.g. 255 works).  A lower value may help memory usage (slightly)
- * and may even improve performance on some systems (and degrade it on others.)
+ * maximum for size_t. The value can be overridden in a library build (pngusr.h,
+ * or set it in CPPFLAGS) and it works to set it to a considerably lower value
+ * (e.g. 255 works).  A lower value may help memory usage (slightly) and may
+ * even improve performance on some systems (and degrade it on others.)
  */
 #ifndef ZLIB_IO_MAX
 #  define ZLIB_IO_MAX ((uInt)-1)
@@ -94,13 +96,13 @@ typedef struct png_xy
  */
 typedef struct png_XYZ
 {
-   png_fixed_point redX, redY, redZ;
-   png_fixed_point greenX, greenY, greenZ;
-   png_fixed_point blueX, blueY, blueZ;
+   png_fixed_point red_X, red_Y, red_Z;
+   png_fixed_point green_X, green_Y, green_Z;
+   png_fixed_point blue_X, blue_Y, blue_Z;
 } png_XYZ;
 #endif /* COLORSPACE */
 
-#if defined PNG_COLORSPACE_SUPPORTED || defined PNG_GAMMA_SUPPORTED
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
 /* A colorspace is all the above plus, potentially, profile information,
  * however at present libpng does not use the profile internally so it is only
  * stored in the png_info struct (if iCCP is supported.)  The rendering intent
@@ -128,349 +130,431 @@ typedef struct png_colorspace
 
 typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
 
+/* General flags for the 'flags' field */
 #define PNG_COLORSPACE_HAVE_GAMMA           0x0001
 #define PNG_COLORSPACE_HAVE_ENDPOINTS       0x0002
 #define PNG_COLORSPACE_HAVE_INTENT          0x0004
 #define PNG_COLORSPACE_FROM_gAMA            0x0008
 #define PNG_COLORSPACE_FROM_cHRM            0x0010
-#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0020
-#define PNG_COLORSPACE_MATCHES_sRGB         0x0040 /* exact match on profile */
+#define PNG_COLORSPACE_FROM_sRGB            0x0020
+#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
+#define PNG_COLORSPACE_MATCHES_sRGB         0x0080 /* exact match on profile */
+#define PNG_COLORSPACE_RGB_TO_GRAY_SET      0x0100 /* user specified coeffs */
 #define PNG_COLORSPACE_INVALID              0x8000
 #define PNG_COLORSPACE_CANCEL(flags)        (0xffff ^ (flags))
 #endif /* COLORSPACE || GAMMA */
 
 struct png_struct_def
 {
+   /* Rearranged in libpng 1.7 to attempt to lessen padding; in general
+    * (char), (short), (int) and pointer types are kept separate, however
+    * associated members under the control of the same #define are still
+    * together.
+    */
 #ifdef PNG_SETJMP_SUPPORTED
-   jmp_buf jmp_buf_local;     /* New name in 1.6.0 for jmp_buf in png_struct */
-   png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
-   jmp_buf *jmp_buf_ptr;      /* passed to longjmp_fn */
-   size_t jmp_buf_size;       /* size of the above, if allocated */
-#endif
-   png_error_ptr error_fn;    /* function for printing errors and aborting */
-#ifdef PNG_WARNINGS_SUPPORTED
-   png_error_ptr warning_fn;  /* function for printing warnings */
-#endif
-   png_voidp error_ptr;       /* user supplied struct for error functions */
-   png_rw_ptr write_data_fn;  /* function for writing output data */
-   png_rw_ptr read_data_fn;   /* function for reading input data */
-   png_voidp io_ptr;          /* ptr to application struct for I/O functions */
-
-#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
-   png_user_transform_ptr read_user_transform_fn; /* user read transform */
+   /* jmp_buf can have very high alignment requirements on some systems, so put
+    * it first (the other setjmp members are later as they are infrequently
+    * accesed.)
+    */
+   jmp_buf jmp_buf_local;
 #endif
 
-#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
-   png_user_transform_ptr write_user_transform_fn; /* user write transform */
-#endif
+   /* Next the frequently accessed fields.  Many processors perform arithmetic
+    * in the address pipeline, but frequently the amount of addition or
+    * subtraction is limited.  By putting these fields at the head of png_struct
+    * the hope is that such processors will generate code that is both smaller
+    * and faster.
+    */
+   png_colorp  palette;        /* palette from the input file */
+   size_t      rowbytes;       /* size of row in bytes */
+   size_t      info_rowbytes;  /* cache of updated row bytes */
+   png_uint_32 width;          /* width of image in pixels */
+   png_uint_32 height;         /* height of image in pixels */
+   png_uint_32 num_rows;       /* number of rows in current pass */
+   png_uint_32 usr_width;      /* width of row at start of write */
+   png_uint_32 iwidth;         /* width of current interlaced row in pixels */
+   png_uint_32 row_number;     /* current row in interlace pass */
+   png_uint_32 chunk_name;     /* PNG_CHUNK() id of current chunk */
+   png_uint_32 crc;            /* current chunk CRC value */
+   png_uint_32 mode;           /* tells us where we are in the PNG file */
+   png_uint_32 flags;          /* flags indicating various things to libpng */
+   png_uint_32 transformations;/* which transformations to perform */
+   png_uint_32 zowner;         /* ID (chunk type) of zstream owner, 0 if none */
+   png_uint_32 free_me;        /* items libpng is responsible for freeing */
 
-/* These were added in libpng-1.0.2 */
-#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-   png_voidp user_transform_ptr; /* user supplied struct for user transform */
-   png_byte user_transform_depth;    /* bit depth of user transformed pixels */
-   png_byte user_transform_channels; /* channels in user transformed pixels */
-#endif
-#endif
-
-   png_uint_32 mode;          /* tells us where we are in the PNG file */
-   png_uint_32 flags;         /* flags indicating various things to libpng */
-   png_uint_32 transformations; /* which transformations to perform */
-
-   png_uint_32 zowner;        /* ID (chunk type) of zstream owner, 0 if none */
-   z_stream    zstream;       /* decompression structure */
-
-#ifdef PNG_WRITE_SUPPORTED
-   png_compression_bufferp zbuffer_list; /* Created on demand during write */
-   uInt                    zbuffer_size; /* size of the actual buffer */
-
-   int zlib_level;            /* holds zlib compression level */
-   int zlib_method;           /* holds zlib compression method */
-   int zlib_window_bits;      /* holds zlib compression window bits */
-   int zlib_mem_level;        /* holds zlib compression memory level */
-   int zlib_strategy;         /* holds zlib compression strategy */
-#endif
-/* Added at libpng 1.5.4 */
-#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
-   int zlib_text_level;            /* holds zlib compression level */
-   int zlib_text_method;           /* holds zlib compression method */
-   int zlib_text_window_bits;      /* holds zlib compression window bits */
-   int zlib_text_mem_level;        /* holds zlib compression memory level */
-   int zlib_text_strategy;         /* holds zlib compression strategy */
-#endif
-/* End of material added at libpng 1.5.4 */
-/* Added at libpng 1.6.0 */
-#ifdef PNG_WRITE_SUPPORTED
-   int zlib_set_level;        /* Actual values set into the zstream on write */
-   int zlib_set_method;
-   int zlib_set_window_bits;
-   int zlib_set_mem_level;
-   int zlib_set_strategy;
-#endif
-
-   png_uint_32 width;         /* width of image in pixels */
-   png_uint_32 height;        /* height of image in pixels */
-   png_uint_32 num_rows;      /* number of rows in current pass */
-   png_uint_32 usr_width;     /* width of row at start of write */
-   png_size_t rowbytes;       /* size of row in bytes */
-   png_uint_32 iwidth;        /* width of current interlaced row in pixels */
-   png_uint_32 row_number;    /* current row in interlace pass */
-   png_uint_32 chunk_name;    /* PNG_CHUNK() id of current chunk */
-   png_bytep prev_row;        /* buffer to save previous (unfiltered) row.
-                               * This is a pointer into big_prev_row
-                               */
-   png_bytep row_buf;         /* buffer to save current (unfiltered) row.
-                               * This is a pointer into big_row_buf
-                               */
-#ifdef PNG_WRITE_SUPPORTED
-   png_bytep sub_row;         /* buffer to save "sub" row when filtering */
-   png_bytep up_row;          /* buffer to save "up" row when filtering */
-   png_bytep avg_row;         /* buffer to save "avg" row when filtering */
-   png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
-#endif
-   png_size_t info_rowbytes;  /* Added in 1.5.4: cache of updated row bytes */
-
-   png_uint_32 idat_size;     /* current IDAT size for read */
-   png_uint_32 crc;           /* current chunk CRC value */
-   png_colorp palette;        /* palette from the input file */
-   png_uint_16 num_palette;   /* number of color entries in palette */
-
-/* Added at libpng-1.5.10 */
+   int         maximum_pixel_depth; /* pixel depth used for the row buffers */
 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-   int num_palette_max;       /* maximum palette index found in IDAT */
+   int         num_palette_max;     /* maximum palette index found in IDAT */
 #endif
 
+   png_uint_16 num_palette;   /* number of color entries in palette */
    png_uint_16 num_trans;     /* number of transparency values */
-   png_byte compression;      /* file compression type (always 0) */
+
+   /* Single byte values, typically used either to save space or to hold 1-byte
+    * values from the PNG chunk specifications.
+    */
+   png_byte compression_type; /* file compression type (always 0) */
    png_byte filter;           /* file filter type (always 0) */
    png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
    png_byte pass;             /* current interlace pass (0 - 6) */
    png_byte do_filter;        /* row filter flags (see PNG_FILTER_ below ) */
    png_byte color_type;       /* color type of file */
    png_byte bit_depth;        /* bit depth of file */
-   png_byte usr_bit_depth;    /* bit depth of users row: write only */
    png_byte pixel_depth;      /* number of bits per pixel */
    png_byte channels;         /* number of channels in file */
-   png_byte usr_channels;     /* channels at start of write: write only */
    png_byte sig_bytes;        /* magic bytes read/written from start of file */
-   png_byte maximum_pixel_depth;
-                              /* pixel depth used for the row buffers */
    png_byte transformed_pixel_depth;
                               /* pixel depth after read/write transforms */
-#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
-   png_uint_16 filler;           /* filler bytes for pixel expansion */
+
+   /* ERROR HANDLING */
+#ifdef PNG_SETJMP_SUPPORTED
+   jmp_buf        *jmp_buf_ptr;   /* passed to longjmp_fn */
+   png_longjmp_ptr longjmp_fn;    /* setjmp non-local goto function. */
+   size_t          jmp_buf_size;  /* size of *jmp_buf_ptr, if allocated */
 #endif
 
-#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
-   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
-   png_byte background_gamma_type;
-   png_fixed_point background_gamma;
-   png_color_16 background;   /* background color in screen gamma space */
-#ifdef PNG_READ_GAMMA_SUPPORTED
-   png_color_16 background_1; /* background normalized to gamma 1.0 */
+   /* Error/warning callbacks */
+   png_error_ptr error_fn;        /* print an error message and abort */
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_error_ptr warning_fn;      /* print a warning and continue */
+#endif
+   png_voidp     error_ptr;       /* user supplied data for the above */
+
+   /* MEMORY ALLOCATION */
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_malloc_ptr malloc_fn; /* allocate memory */
+   png_free_ptr   free_fn;   /* free memory */
+   png_voidp      mem_ptr;   /* user supplied data for the above */
+#endif
+
+   /* IO and BASIC READ/WRITE SUPPORT */
+   png_voidp            io_ptr;       /* user supplied data for IO callbacks */
+
+#ifdef PNG_READ_SUPPORTED
+   png_rw_ptr          read_data_fn;  /* read some bytes (must succeed) */
+   png_read_status_ptr read_row_fn;   /* called after each row is decoded */
+   png_bytep           read_buffer;   /* buffer for reading chunk data */
+
+   /* During read the following array is set up to point to the appropriate
+    * un-filter function, this allows per-image and per-processor optimization.
+    */
+   void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
+      png_bytep row, png_const_bytep prev_row);
+
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+   /* The png_struct colorspace structure is only required on read - on write it
+    * is in (just) the info_struct.
+    */
+   png_colorspace   colorspace;
+#endif
+#endif /* PNG_READ_SUPPORTED */
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   png_uint_32 user_width_max;        /* Maximum width on read */
+   png_uint_32 user_height_max;       /* Maximum height on read */
+   /* Total memory that a single zTXt, sPLT, iTXt, iCCP, or unknown chunk
+    * can occupy when decompressed.  0 means unlimited.  This field is a counter
+    * - it is decremented as memory is allocated.
+    */
+   png_alloc_size_t user_chunk_malloc_max;
+#endif
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   /* limit on total *number* of sPLT, text and unknown chunks that can be
+    * stored.  0 means unlimited.  This field is a counter - it is decremented
+    * as chunks are encountered.
+    */
+   png_uint_32 user_chunk_cache_max;
+#endif
+
+   /* The progressive reader gets passed data and calls application handling
+    * functions when appropriate.
+    */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+   png_progressive_info_ptr info_fn; /* called after header data fully read */
+   png_progressive_row_ptr  row_fn;  /* called after a row is decoded */
+   png_progressive_end_ptr  end_fn;  /* called after image is complete */
+
+   /* Progressive read control data */
+   png_bytep   save_buffer_ptr;      /* current location in save_buffer */
+   png_bytep   save_buffer;          /* buffer for previously read data */
+   png_bytep   current_buffer_ptr;   /* current location in current_buffer */
+   png_bytep   current_buffer;       /* buffer for recently used data */
+
+   size_t      save_buffer_size;     /* amount of data now in save_buffer */
+   size_t      save_buffer_max;      /* total size of save_buffer */
+   size_t      buffer_size;          /* total amount of available input data */
+   size_t      current_buffer_size;  /* amount of data now in current_buffer */
+
+   png_uint_32 push_length;          /* size of current input chunk */
+   png_uint_32 skip_length;          /* bytes to skip in input data */
+
+   int         process_mode;         /* what push library is currently doing */
+   int         cur_palette;          /* current push library palette index */
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+   png_rw_ptr              write_data_fn;/* write some bytes (must succeed) */
+   png_write_status_ptr    write_row_fn; /* called after each row is encoded */
 #endif
-#endif /* PNG_bKGD_SUPPORTED */
 
 #ifdef PNG_WRITE_FLUSH_SUPPORTED
    png_flush_ptr output_flush_fn; /* Function for flushing output */
-   png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
-   png_uint_32 flush_rows;    /* number of rows written since last flush */
-#endif
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-   int gamma_shift;      /* number of "insignificant" bits in 16-bit gamma */
-   png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
-
-   png_bytep gamma_table;     /* gamma table for 8-bit depth files */
-   png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
-   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
-   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-   png_bytep gamma_from_1;    /* converts from 1.0 to screen */
-   png_bytep gamma_to_1;      /* converts from file to 1.0 */
-   png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
-   png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
-#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
-   png_color_8 sig_bit;       /* significant bits in each available channel */
-#endif
-
-#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
-   png_color_8 shift;         /* shift for significant bit tranformation */
-#endif
-
-#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
- || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   png_bytep trans_alpha;           /* alpha values for paletted files */
-   png_color_16 trans_color;  /* transparent color for non-paletted files */
-#endif
-
-   png_read_status_ptr read_row_fn;   /* called after each row is decoded */
-   png_write_status_ptr write_row_fn; /* called after each row is encoded */
-#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-   png_progressive_info_ptr info_fn; /* called after header data fully read */
-   png_progressive_row_ptr row_fn;   /* called after a prog. row is decoded */
-   png_progressive_end_ptr end_fn;   /* called after image is complete */
-   png_bytep save_buffer_ptr;        /* current location in save_buffer */
-   png_bytep save_buffer;            /* buffer for previously read data */
-   png_bytep current_buffer_ptr;     /* current location in current_buffer */
-   png_bytep current_buffer;         /* buffer for recently used data */
-   png_uint_32 push_length;          /* size of current input chunk */
-   png_uint_32 skip_length;          /* bytes to skip in input data */
-   png_size_t save_buffer_size;      /* amount of data now in save_buffer */
-   png_size_t save_buffer_max;       /* total size of save_buffer */
-   png_size_t buffer_size;           /* total amount of available input data */
-   png_size_t current_buffer_size;   /* amount of data now in current_buffer */
-   int process_mode;                 /* what push library is currently doing */
-   int cur_palette;                  /* current push library palette index */
-
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-
-#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
-/* For the Borland special 64K segment handler */
-   png_bytepp offset_table_ptr;
-   png_bytep offset_table;
-   png_uint_16 offset_table_number;
-   png_uint_16 offset_table_count;
-   png_uint_16 offset_table_count_free;
-#endif
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
-   png_bytep palette_lookup; /* lookup table for quantizing */
-   png_bytep quantize_index; /* index translation for palette files */
+   png_uint_32   flush_dist; /* how many rows apart to flush, 0 - no flush */
+   png_uint_32   flush_rows; /* number of rows written since last flush */
 #endif
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-   png_byte heuristic_method;        /* heuristic for row filter selection */
-   png_byte num_prev_filters;        /* number of weights for previous rows */
-   png_bytep prev_filters;           /* filter type(s) of previous row(s) */
+   png_bytep    prev_filters;        /* filter type(s) of previous row(s) */
    png_uint_16p filter_weights;      /* weight(s) for previous line(s) */
    png_uint_16p inv_filter_weights;  /* 1/weight(s) for previous line(s) */
    png_uint_16p filter_costs;        /* relative filter calculation cost */
    png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
+   png_byte     heuristic_method;    /* heuristic for row filter selection */
+   png_byte     num_prev_filters;    /* number of weights for previous rows */
 #endif
 
-#if PNG_LIBPNG_VER < 10700
-#ifdef PNG_TIME_RFC1123_SUPPORTED
-   char time_buffer[29]; /* String to hold RFC 1123 time text */
-#endif
-#endif
-
-/* New members added in libpng-1.0.6 */
-
-   png_uint_32 free_me;    /* flags items libpng is responsible for freeing */
-
-#ifdef PNG_USER_CHUNKS_SUPPORTED
-   png_voidp user_chunk_ptr;
-   png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
-#endif
-
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   unsigned int num_chunk_list;
-   png_bytep chunk_list;
-#endif
-
-/* New members added in libpng-1.0.3 */
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
-   png_byte rgb_to_gray_status;
-   /* Added in libpng 1.5.5 to record setting of coefficients: */
-   png_byte rgb_to_gray_coefficients_set;
-   /* These were changed from png_byte in libpng-1.0.6 */
-   png_uint_16 rgb_to_gray_red_coeff;
-   png_uint_16 rgb_to_gray_green_coeff;
-   /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
-#endif
-
-/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
-/* Changed from png_byte to png_uint_32 at version 1.2.0 */
-   png_uint_32 mng_features_permitted;
-#endif
-
-/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
-#ifdef PNG_MNG_FEATURES_SUPPORTED
-   png_byte filter_type;
-#endif
-
-/* New members added in libpng-1.2.0 */
-
-/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
-#ifdef PNG_USER_MEM_SUPPORTED
-   png_voidp mem_ptr;             /* user supplied struct for mem functions */
-   png_malloc_ptr malloc_fn;      /* function for allocating memory */
-   png_free_ptr free_fn;          /* function for freeing memory */
-#endif
-
-/* New member added in libpng-1.0.13 and 1.2.0 */
-   png_bytep big_row_buf;         /* buffer to save current (unfiltered) row */
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
-/* The following three members were added at version 1.0.14 and 1.2.4 */
-   png_bytep quantize_sort;          /* working sort array */
-   png_bytep index_to_palette;       /* where the original index currently is
-                                        in the palette */
-   png_bytep palette_to_index;       /* which original index points to this
-                                         palette color */
-#endif
-
-/* New members added in libpng-1.0.16 and 1.2.6 */
-   png_byte compression_type;
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
-   png_uint_32 user_width_max;
-   png_uint_32 user_height_max;
-
-   /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
-    * chunks that can be stored (0 means unlimited).
-    */
-   png_uint_32 user_chunk_cache_max;
-
-   /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
-    * can occupy when decompressed.  0 means unlimited.
-    */
-   png_alloc_size_t user_chunk_malloc_max;
-#endif
-
-/* New member added in libpng-1.0.25 and 1.2.17 */
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
-   /* Temporary storage for unknown chunk that the library doesn't recognize,
-    * used while reading the chunk.
-    */
-#ifdef PNG_READ_SUPPORTED
-   png_unknown_chunk unknown_chunk;
-#endif
-#endif
-
-/* New member added in libpng-1.2.26 */
-  png_size_t old_big_row_buf_size;
-
-#ifdef PNG_READ_SUPPORTED
-/* New member added in libpng-1.2.30 */
-  png_bytep        read_buffer;      /* buffer for reading chunk data */
-  png_alloc_size_t read_buffer_size; /* current size of the buffer */
-#endif
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-  uInt             IDAT_read_size;   /* limit on read buffer size for IDAT */
+#ifdef PNG_WRITE_SUPPORTED
+   png_byte     usr_bit_depth;       /* bit depth of users row */
+   png_byte     usr_channels;        /* channels at start of write */
 #endif
 
 #ifdef PNG_IO_STATE_SUPPORTED
-/* New member added in libpng-1.4.0 */
-   png_uint_32 io_state;
+   png_uint_32          io_state;     /* tells the app read/write progress */
 #endif
 
-/* New member added in libpng-1.5.6 */
-   png_bytep big_prev_row;
-
-   void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
-      png_bytep row, png_const_bytep prev_row);
+   /* ROW BUFFERS
+    *
+    * Members that hold pointers to the decompressed image rows.
+    */
+   png_bytep row_buf;  /* buffer for the current (unfiltered) row */
+#if defined(PNG_WRITE_FILTER_SUPPORTED) || defined(PNG_READ_SUPPORTED)
+   png_bytep prev_row; /* buffer to save the previous (unfiltered) row */
+#endif
 
 #ifdef PNG_READ_SUPPORTED
-#if defined PNG_COLORSPACE_SUPPORTED || defined PNG_GAMMA_SUPPORTED
-   png_colorspace   colorspace;
+   /* The row_buf and prev_row pointers are misaligned so that the start of the
+    * row - after the filter byte - is aligned, the 'big_' pointers record the
+    * original allocated pointer.
+    */
+   png_bytep big_row_buf;
+   png_bytep big_prev_row;
+   size_t    big_row_buf_size; /* Actual size of both */
 #endif
+
+#ifdef PNG_WRITE_SUPPORTED
+   /* This is somewhat excessive, there is no obvious reason on write to
+    * allocate a buffer for each possible filtered row, only for the one being
+    * tested and the current best.
+    *
+    * TODO: fix this
+    */
+   png_bytep sub_row;         /* buffer to save "sub" row when filtering */
+   png_bytep up_row;          /* buffer to save "up" row when filtering */
+   png_bytep avg_row;         /* buffer to save "avg" row when filtering */
+   png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
+#endif
+
+   /* UNKNOWN CHUNK HANDLING */
+   /* TODO: this is excessively complicated, there are multiple ways of doing
+    * the same thing.  It should be cleaned up, possibly by finding out which
+    * APIs applications really use.
+    */
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+   /* General purpose pointer for all user/unknown chunk handling; points to
+    * application supplied data for use in the read_user_chunk_fn callback
+    * (currently there is no write side support - the write side must use the
+    * set_unknown_chunks interface.)
+    */
+   png_voidp user_chunk_ptr;
+#endif
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   /* This is called back from the unknown chunk handling */
+   png_user_chunk_ptr     read_user_chunk_fn; /* user read chunk handler */
+#endif
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   /* Temporary storage for unknown chunk that the library doesn't recognize,
+    * used while reading the chunk.
+    */
+   png_unknown_chunk unknown_chunk;
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   png_bytep    chunk_list;      /* List of png_byte[5]; the textual chunk name
+                                  * followed by a PNG_HANDLE_* byte */
+   int          unknown_default; /* As PNG_HANDLE_* */
+   unsigned int num_chunk_list;  /* Number of entries in the list */
+#endif
+
+   /* USER TRANSFORM SUPPORT */
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   png_user_transform_ptr read_user_transform_fn; /* user read transform */
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   png_user_transform_ptr write_user_transform_fn; /* user write transform */
+#endif
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+   png_voidp user_transform_ptr;      /* user supplied data for the above */
+   png_byte  user_transform_depth;    /* bit depth of user transformed pixels */
+   png_byte  user_transform_channels; /* channels in user transformed pixels */
+#endif
+
+   /* READ TRANSFORM SUPPORT
+    *
+    * Quite a lot of things can be done to the original image data on read, and
+    * most of these are configurable.  The data required by the configurable
+    * read transforms should be stored here.  The png_color_16 and png_color_8
+    * structures have low alignment requirements and odd sizes, so may cause
+    * misalignment when present.  Member alignment is as follows:
+    *
+    *    png_color_16   png_uint_16
+    *    png_color_8    png_byte
+    */
+   /* GAMMA/BACKGROUND/ALPHA-MODE/RGB-TO-GRAY/tRNS/sBIT
+    *
+    * These things are all interrelated because they need some or all of the
+    * gamma tables.  Some attempt has been made below to order these members by
+    * size, so that as little padding as possible is required.
+    */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_bytep gamma_table;        /* gamma table for 8-bit depth files */
+   png_uint_16p gamma_16_table;  /* gamma table for 16-bit depth files */
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) ||\
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   png_bytep gamma_from_1;       /* converts from 1.0 to screen */
+   png_uint_16p gamma_to_1;      /* converts from file to 1.0 */
+   png_uint_16p gamma_16_from_1; /* converts from 1.0 to screen */
+   png_uint_16p gamma_16_to_1;   /* converts from file to 1.0 */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+#endif /* PNG_READ_GAMMA_SUPPORTED */
+
+#if defined(PNG_READ_tRNS_SUPPORTED) || \
+   defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_EXPAND_SUPPORTED)
+   png_bytep trans_alpha;           /* alpha values for paletted files */
+#endif
+
+   /* Integer values */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   png_fixed_point background_gamma;
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
+   int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */
+#endif
+
+   /* png_color_16 */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   png_color_16 background;   /* background color in screen gamma space */
+   png_color_16 background_1; /* background normalized to gamma 1.0 */
+#endif
+#if defined(PNG_READ_tRNS_SUPPORTED) || \
+   defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_EXPAND_SUPPORTED)
+   png_color_16 trans_color;  /* transparent color for non-paletted files */
+#endif
+
+   /* png_uint_16 */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   png_uint_16 rgb_to_gray_red_coeff;
+   png_uint_16 rgb_to_gray_green_coeff;
+   /* The blue coefficient is calculated from the above */
+#endif
+
+   /* png_color_8 */
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_sBIT_SUPPORTED)
+   png_color_8 sig_bit;       /* significant bits in each available channel */
+#endif
+
+   /* png_byte */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   png_byte background_gamma_type;
+#endif
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   png_byte rgb_to_gray_status;
+#endif
+
+   /* SHIFT - both READ_SHIFT and WRITE_SHIFT */
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+   png_color_8 shift;         /* shift for significant bit tranformation */
+#endif
+
+   /* FILLER SUPPORT (pixel expansion or read, contraction on write) */
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+   png_uint_16 filler;              /* filler bytes for pixel expansion */
+#endif
+
+   /* QUANTIZE (convert to color-mapped) */
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   png_bytep palette_lookup;   /* lookup table for quantizing */
+   png_bytep quantize_index;   /* index translation for palette files */
+   png_bytep quantize_sort;    /* working sort array */
+   png_bytep index_to_palette; /* where the original index currently is in the
+                                * palette
+                                */
+   png_bytep palette_to_index; /* which original index points to this palette
+                                * color
+                                */
+#endif
+
+   /* MNG SUPPORT */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   png_uint_32 mng_features_permitted;
+   png_byte filter_type;
+#endif
+
+   /* Options */
+#ifdef PNG_SET_OPTION_SUPPORTED
+   png_byte options;           /* On/off state (up to 4 options) */
+#endif
+
+   /* COMPRESSION AND DECOMPRESSION SUPPORT.
+    *
+    * zlib expects a 'zstream' as the fundamental control structure, it allows
+    * all the parameters to be passed as one pointer.
+    */
+   z_stream    zstream;       /* decompression structure */
+
+#ifdef PNG_READ_SUPPORTED
+   /* These, and IDAT_read_size below, control how much input and output (at
+    * most) is available to zlib.
+    */
+   png_uint_32      idat_size;        /* current IDAT size for read */
+   png_alloc_size_t read_buffer_size; /* current size of the buffer */
+#endif
+
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   int zlib_text_level;       /* holds zlib compression level */
+   int zlib_text_method;      /* holds zlib compression method */
+   int zlib_text_window_bits; /* holds zlib compression window bits */
+   int zlib_text_mem_level;   /* holds zlib compression memory level */
+   int zlib_text_strategy;    /* holds zlib compression strategy */
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+   int zlib_level;            /* holds zlib compression level */
+   int zlib_method;           /* holds zlib compression method */
+   int zlib_window_bits;      /* holds zlib compression window bits */
+   int zlib_mem_level;        /* holds zlib compression memory level */
+   int zlib_strategy;         /* holds zlib compression strategy */
+
+   int zlib_set_level;        /* Actual values set into the zstream on write */
+   int zlib_set_method;
+   int zlib_set_window_bits;
+   int zlib_set_mem_level;
+   int zlib_set_strategy;
+
+   png_compression_bufferp zbuffer_list; /* Created on demand during write */
+   uInt                    zbuffer_size; /* size of the actual zlib buffer */
+#endif
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+   uInt IDAT_read_size;       /* limit on read buffer size for IDAT */
 #endif
 };
 #endif /* PNGSTRUCT_H */

pngtest.c

@@ -1,8 +1,8 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -33,16 +33,39 @@
 
 #define _POSIX_SOURCE 1
 
-#include "zlib.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Defined so I can write to a file on gui/windowing platforms */
+/*  #define STDERR stderr  */
+#define STDERR stdout   /* For DOS */
+
 #include "png.h"
+
+/* Known chunks that exist in pngtest.png must be supported or pngtest will fail
+ * simply as a result of re-ordering them.  This may be fixed in 1.7
+ */
+#if defined PNG_READ_SUPPORTED && /* else nothing can be done */\
+   defined PNG_READ_bKGD_SUPPORTED &&\
+   defined PNG_READ_cHRM_SUPPORTED &&\
+   defined PNG_READ_gAMA_SUPPORTED &&\
+   defined PNG_READ_oFFs_SUPPORTED &&\
+   defined PNG_READ_pCAL_SUPPORTED &&\
+   defined PNG_READ_pHYs_SUPPORTED &&\
+   defined PNG_READ_sBIT_SUPPORTED &&\
+   defined PNG_READ_sCAL_SUPPORTED &&\
+   defined PNG_READ_sRGB_SUPPORTED &&\
+   defined PNG_READ_tEXt_SUPPORTED &&\
+   defined PNG_READ_tIME_SUPPORTED &&\
+   defined PNG_READ_zTXt_SUPPORTED
+
+#include PNG_ZLIB_HEADER /* defined by pnglibconf.h */
 /* Copied from pngpriv.h but only used in error messages below. */
 #ifndef PNG_ZBUF_SIZE
 #  define PNG_ZBUF_SIZE 8192
 #endif
-#  include <stdio.h>
-#  include <stdlib.h>
-#  include <string.h>
-#  define FCLOSE(file) fclose(file)
+#define FCLOSE(file) fclose(file)
 
 #ifndef PNG_STDIO_SUPPORTED
 typedef FILE                * png_FILE_p;
@@ -88,20 +111,27 @@ static char tIME_string[PNG_tIME_STRING_LENGTH] = "tIME chunk is not present";
 
 static int verbose = 0;
 static int strict = 0;
-
-#ifdef __TURBOC__
-#include <mem.h>
-#endif
-
-/* Defined so I can write to a file on gui/windowing platforms */
-/*  #define STDERR stderr  */
-#define STDERR stdout   /* For DOS */
+static int relaxed = 0;
+static int unsupported_chunks = 0; /* chunk unsupported by libpng in input */
+static int error_count = 0; /* count calls to png_error */
+static int warning_count = 0; /* count calls to png_warning */
 
 /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
 #ifndef png_jmpbuf
 #  define png_jmpbuf(png_ptr) png_ptr->jmpbuf
 #endif
 
+/* Defines for unknown chunk handling if required. */
+#ifndef PNG_HANDLE_CHUNK_ALWAYS
+#  define PNG_HANDLE_CHUNK_ALWAYS       3
+#endif
+#ifndef PNG_HANDLE_CHUNK_IF_SAFE
+#  define PNG_HANDLE_CHUNK_IF_SAFE      2
+#endif
+
+/* Utility to save typing/errors, the argument must be a name */
+#define MEMZERO(var) ((void)memset(&var, 0, sizeof var))
+
 /* Example of using row callbacks to make a simple progress meter */
 static int status_pass = 1;
 static int status_dots_requested = 0;
@@ -131,6 +161,7 @@ read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
    fprintf(stdout, "r");
 }
 
+#ifdef PNG_WRITE_SUPPORTED
 static void PNGCBAPI
 write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
 {
@@ -139,6 +170,7 @@ write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
 
    fprintf(stdout, "w");
 }
+#endif
 
 
 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
@@ -269,8 +301,6 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
 }
 #endif /* PNG_WRITE_USER_TRANSFORM_SUPPORTED */
 
-static int wrote_question = 0;
-
 #ifndef PNG_STDIO_SUPPORTED
 /* START of code to validate stdio-free compilation */
 /* These copies of the default read/write functions come from pngrio.c and
@@ -378,24 +408,31 @@ pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
    pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING);
 #endif
 }
+#endif /* !PNG_STDIO_SUPPORTED */
 
 /* This function is called when there is a warning, but the library thinks
  * it can continue anyway.  Replacement functions don't have to do anything
  * here if you don't want to.  In the default configuration, png_ptr is
  * not used, but it is passed in case it may be useful.
  */
+typedef struct
+{
+   PNG_CONST char *file_name;
+}  pngtest_error_parameters;
+
 static void PNGCBAPI
 pngtest_warning(png_structp png_ptr, png_const_charp message)
 {
    PNG_CONST char *name = "UNKNOWN (ERROR!)";
-   char *test;
-   test = png_get_error_ptr(png_ptr);
+   pngtest_error_parameters *test =
+      (pngtest_error_parameters*)png_get_error_ptr(png_ptr);
 
-   if (test == NULL)
-     fprintf(STDERR, "%s: libpng warning: %s\n", name, message);
+   ++warning_count;
 
-   else
-     fprintf(STDERR, "%s: libpng warning: %s\n", test, message);
+   if (test != NULL && test->file_name != NULL)
+      name = test->file_name;
+
+   fprintf(STDERR, "%s: libpng warning: %s\n", name, message);
 }
 
 /* This is the default error handling function.  Note that replacements for
@@ -406,12 +443,14 @@ pngtest_warning(png_structp png_ptr, png_const_charp message)
 static void PNGCBAPI
 pngtest_error(png_structp png_ptr, png_const_charp message)
 {
+   ++error_count;
+
    pngtest_warning(png_ptr, message);
    /* We can return because png_error calls the default handler, which is
     * actually OK in this case.
     */
 }
-#endif /* !PNG_STDIO_SUPPORTED */
+
 /* END of code to validate stdio-free compilation */
 
 /* START of code to validate memory allocation and deallocation */
@@ -462,7 +501,7 @@ PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size)
       memory_infop pinfo;
       png_set_mem_fn(png_ptr, NULL, NULL, NULL);
       pinfo = (memory_infop)png_malloc(png_ptr,
-         png_sizeof(*pinfo));
+         (sizeof *pinfo));
       pinfo->size = size;
       current_allocation += size;
       total_allocation += size;
@@ -530,7 +569,8 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
             /* We must free the list element too, but first kill
                the memory that is to be freed. */
             memset(ptr, 0x55, pinfo->size);
-            png_free_default(png_ptr, pinfo);
+            if (pinfo)
+               free(pinfo);
             pinfo = NULL;
             break;
          }
@@ -549,32 +589,81 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
    if (verbose)
       printf("Freeing %p\n", ptr);
 
-   png_free_default(png_ptr, ptr);
+   if (ptr)
+      free(ptr);
    ptr = NULL;
 }
 #endif /* PNG_USER_MEM_SUPPORTED && PNG_DEBUG */
 /* END of code to test memory allocation/deallocation */
 
 
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
 /* Demonstration of user chunk support of the sTER and vpAg chunks */
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
 
 /* (sTER is a public chunk not yet known by libpng.  vpAg is a private
 chunk used in ImageMagick to store "virtual page" size).  */
 
-static png_uint_32 user_chunk_data[4];
+static struct user_chunk_data
+{
+   png_const_infop info_ptr;
+   png_uint_32     vpAg_width, vpAg_height;
+   png_byte        vpAg_units;
+   png_byte        sTER_mode;
+   int             location[2];
+}
+user_chunk_data;
 
-    /* 0: sTER mode + 1
-     * 1: vpAg width
-     * 2: vpAg height
-     * 3: vpAg units
-     */
+/* Used for location and order; zero means nothing. */
+#define have_sTER   0x01
+#define have_vpAg   0x02
+#define before_PLTE 0x10
+#define before_IDAT 0x20
+#define after_IDAT  0x40
+
+static void
+init_callback_info(png_const_infop info_ptr)
+{
+   MEMZERO(user_chunk_data);
+   user_chunk_data.info_ptr = info_ptr;
+}
+
+static int
+set_location(png_structp png_ptr, struct user_chunk_data *data, int what)
+{
+   int location;
+
+   if ((data->location[0] & what) || (data->location[1] & what))
+      return 0; /* already have one of these */
+
+   /* Find where we are (the code below zeros info_ptr to indicate that the
+    * chunks before the first IDAT have been read.)
+    */
+   if (data->info_ptr == NULL) /* after IDAT */
+      location = what | after_IDAT;
+
+   else if (png_get_valid(png_ptr, data->info_ptr, PNG_INFO_PLTE))
+      location = what | before_IDAT;
+
+   else
+      location = what | before_PLTE;
+
+   if (data->location[0] == 0)
+      data->location[0] = location;
+
+   else
+      data->location[1] = location;
+
+   return 1; /* handled */
+}
 
 static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr,
    png_unknown_chunkp chunk)
 {
-   png_uint_32
-     *my_user_chunk_data;
+   struct user_chunk_data *my_user_chunk_data =
+      (struct user_chunk_data*)png_get_user_chunk_ptr(png_ptr);
+
+   if (my_user_chunk_data == NULL)
+      png_error(png_ptr, "lost user chunk pointer");
 
    /* Return one of the following:
     *    return (-n);  chunk had an error
@@ -599,9 +688,14 @@ static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr,
          if (chunk->data[0] != 0 && chunk->data[0] != 1)
             return (-1);  /* Invalid mode */
 
-         my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr);
-         my_user_chunk_data[0]=chunk->data[0]+1;
-         return (1);
+         if (set_location(png_ptr, my_user_chunk_data, have_sTER))
+         {
+            my_user_chunk_data->sTER_mode=chunk->data[0];
+            return (1);
+         }
+
+         else
+            return (0); /* duplicate sTER - give it to libpng */
       }
 
    if (chunk->name[0] != 118 || chunk->name[1] != 112 ||    /* v  p */
@@ -613,24 +707,119 @@ static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr,
    if (chunk->size != 9)
       return (-1); /* Error return */
 
-   my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr);
+   if (!set_location(png_ptr, my_user_chunk_data, have_vpAg))
+      return (0);  /* duplicate vpAg */
 
-   my_user_chunk_data[1]=png_get_uint_31(png_ptr, chunk->data);
-   my_user_chunk_data[2]=png_get_uint_31(png_ptr, chunk->data + 4);
-   my_user_chunk_data[3]=(png_uint_32)chunk->data[8];
+   my_user_chunk_data->vpAg_width = png_get_uint_31(png_ptr, chunk->data);
+   my_user_chunk_data->vpAg_height = png_get_uint_31(png_ptr, chunk->data + 4);
+   my_user_chunk_data->vpAg_units = chunk->data[8];
 
    return (1);
-
 }
+
+#ifdef PNG_WRITE_SUPPORTED
+static void
+write_sTER_chunk(png_structp write_ptr)
+{
+   png_byte sTER[5] = {115,  84,  69,  82, '\0'};
+
+   if (verbose)
+      fprintf(STDERR, "\n stereo mode = %d\n", user_chunk_data.sTER_mode);
+
+   png_write_chunk(write_ptr, sTER, &user_chunk_data.sTER_mode, 1);
+}
+
+static void
+write_vpAg_chunk(png_structp write_ptr)
+{
+   png_byte vpAg[5] = {118, 112,  65, 103, '\0'};
+
+   png_byte vpag_chunk_data[9];
+
+   if (verbose)
+      fprintf(STDERR, " vpAg = %lu x %lu, units = %d\n",
+        (unsigned long)user_chunk_data.vpAg_width,
+        (unsigned long)user_chunk_data.vpAg_height,
+        user_chunk_data.vpAg_units);
+
+   png_save_uint_32(vpag_chunk_data, user_chunk_data.vpAg_width);
+   png_save_uint_32(vpag_chunk_data + 4, user_chunk_data.vpAg_height);
+   vpag_chunk_data[8] = user_chunk_data.vpAg_units;
+   png_write_chunk(write_ptr, vpAg, vpag_chunk_data, 9);
+}
+
+static void
+write_chunks(png_structp write_ptr, int location)
+{
+   int i;
+
+   /* Notice that this preserves the original chunk order, however chunks
+    * intercepted by the callback will be written *after* chunks passed to
+    * libpng.  This will actually reverse a pair of sTER chunks or a pair of
+    * vpAg chunks, resulting in an error later.  This is not worth worrying
+    * about - the chunks should not be duplicated!
+    */
+   for (i=0; i<2; ++i)
+   {
+      if (user_chunk_data.location[i] == (location | have_sTER))
+         write_sTER_chunk(write_ptr);
+
+      else if (user_chunk_data.location[i] == (location | have_vpAg))
+         write_vpAg_chunk(write_ptr);
+   }
+}
+#endif /* PNG_WRITE_SUPPORTED */
+#else /* !PNG_READ_USER_CHUNKS_SUPPORTED */
+#  define write_chunks(pp,loc) ((void)0)
 #endif
 /* END of code to demonstrate user chunk support */
 
+/* START of code to check that libpng has the required text support; this only
+ * checks for the write support because if read support is missing the chunk
+ * will simply not be reported back to pngtest.
+ */
+#ifdef PNG_TEXT_SUPPORTED
+static void
+pngtest_check_text_support(png_const_structp png_ptr, png_textp text_ptr,
+   int num_text)
+{
+   while (num_text > 0)
+   {
+      switch (text_ptr[--num_text].compression)
+      {
+         case PNG_TEXT_COMPRESSION_NONE:
+            break;
+
+         case PNG_TEXT_COMPRESSION_zTXt:
+#           ifndef PNG_WRITE_zTXt_SUPPORTED
+               ++unsupported_chunks;
+#           endif
+            break;
+
+         case PNG_ITXT_COMPRESSION_NONE:
+         case PNG_ITXT_COMPRESSION_zTXt:
+#           ifndef PNG_WRITE_iTXt_SUPPORTED
+               ++unsupported_chunks;
+#           endif
+            break;
+
+         default:
+            /* This is an error */
+            png_error(png_ptr, "invalid text chunk compression field");
+            break;
+      }
+   }
+}
+#endif
+/* END of code to check that libpng has the required text support */
+
 /* Test one file */
 static int
 test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 {
    static png_FILE_p fpin;
    static png_FILE_p fpout;  /* "static" prevents setjmp corruption */
+   pngtest_error_parameters error_parameters;
    png_structp read_ptr;
    png_infop read_info_ptr, end_info_ptr;
 #ifdef PNG_WRITE_SUPPORTED
@@ -648,9 +837,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    int num_pass, pass;
    int bit_depth, color_type;
 
-   char inbuf[256], outbuf[256];
-
    row_buf = NULL;
+   error_parameters.file_name = inname;
 
    if ((fpin = fopen(inname, "rb")) == NULL)
    {
@@ -674,20 +862,9 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    read_ptr =
       png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
-#ifndef PNG_STDIO_SUPPORTED
-   png_set_error_fn(read_ptr, (png_voidp)inname, pngtest_error,
-       pngtest_warning);
-#endif
+   png_set_error_fn(read_ptr, &error_parameters, pngtest_error,
+      pngtest_warning);
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
-   user_chunk_data[0] = 0;
-   user_chunk_data[1] = 0;
-   user_chunk_data[2] = 0;
-   user_chunk_data[3] = 0;
-   png_set_read_user_chunk_fn(read_ptr, user_chunk_data,
-     read_user_chunk_callback);
-
-#endif
 #ifdef PNG_WRITE_SUPPORTED
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
    write_ptr =
@@ -697,10 +874,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    write_ptr =
       png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
-#ifndef PNG_STDIO_SUPPORTED
-   png_set_error_fn(write_ptr, (png_voidp)inname, pngtest_error,
-       pngtest_warning);
-#endif
+   png_set_error_fn(write_ptr, &error_parameters, pngtest_error,
+      pngtest_warning);
 #endif
    pngtest_debug("Allocating read_info, write_info and end_info structures");
    read_info_ptr = png_create_info_struct(read_ptr);
@@ -710,6 +885,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    write_end_info_ptr = png_create_info_struct(write_ptr);
 #endif
 
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   init_callback_info(read_info_ptr);
+   png_set_read_user_chunk_fn(read_ptr, &user_chunk_data,
+     read_user_chunk_callback);
+#endif
+
 #ifdef PNG_SETJMP_SUPPORTED
    pngtest_debug("Setting jmpbuf for read struct");
    if (setjmp(png_jmpbuf(read_ptr)))
@@ -749,11 +930,26 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       /* Treat png_benign_error() as errors on read */
       png_set_benign_errors(read_ptr, 0);
-   
+
+#ifdef PNG_WRITE_SUPPORTED
       /* Treat them as errors on write */
       png_set_benign_errors(write_ptr, 0);
+#endif
 
-      /* if strict is not set, then both are treated as warnings. */
+      /* if strict is not set, then app warnings and errors are treated as
+       * warnings in release builds, but not in unstable builds; this can be
+       * changed with '--relaxed'.
+       */
+   }
+
+   else if (relaxed)
+   {
+      /* Allow application (pngtest) errors and warnings to pass */
+      png_set_benign_errors(read_ptr, 1);
+
+#ifdef PNG_WRITE_SUPPORTED
+      png_set_benign_errors(write_ptr, 1);
+#endif
    }
 
    pngtest_debug("Initializing input and output streams");
@@ -774,14 +970,6 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #  endif
 #endif
 
-#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
-   /* Normally one would use Z_DEFAULT_STRATEGY for text compression.
-    * This is here just to make pngtest replicate the results from libpng
-    * versions prior to 1.5.4, and to test this new API.
-    */
-   png_set_text_compression_strategy(write_ptr, Z_FILTERED);
-#endif
-
    if (status_dots_requested == 1)
    {
 #ifdef PNG_WRITE_SUPPORTED
@@ -813,24 +1001,37 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_set_write_user_transform_fn(write_ptr, count_zero_samples);
 #endif
 
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-#  ifndef PNG_HANDLE_CHUNK_ALWAYS
-#    define PNG_HANDLE_CHUNK_ALWAYS       3
-#  endif
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   /* Preserve all the unknown chunks, if possible.  If this is disabled then,
+    * even if the png_{get,set}_unknown_chunks stuff is enabled, we can't use
+    * libpng to *save* the unknown chunks on read (because we can't switch the
+    * save option on!)
+    *
+    * Notice that if SET_UNKNOWN_CHUNKS is *not* supported read will discard all
+    * unknown chunks and write will write them all.
+    */
+#ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
    png_set_keep_unknown_chunks(read_ptr, PNG_HANDLE_CHUNK_ALWAYS,
       NULL, 0);
 #endif
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-#  ifndef PNG_HANDLE_CHUNK_IF_SAFE
-#    define PNG_HANDLE_CHUNK_IF_SAFE      2
-#  endif
-   png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_IF_SAFE,
+   png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_ALWAYS,
       NULL, 0);
+#endif
 #endif
 
    pngtest_debug("Reading info struct");
    png_read_info(read_ptr, read_info_ptr);
 
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   /* This is a bit of a hack; there is no obvious way in the callback function
+    * to determine that the chunks before the first IDAT have been read, so
+    * remove the info_ptr (which is only used to determine position relative to
+    * PLTE) here to indicate that we are after the IDAT.
+    */
+   user_chunk_data.info_ptr = NULL;
+#endif
+
    pngtest_debug("Transferring info struct");
    {
       int interlace_type, compression_type, filter_type;
@@ -986,7 +1187,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    }
 #endif
 #ifdef PNG_sCAL_SUPPORTED
-#ifdef PNG_FLOATING_POINT_SUPPORTED
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+   defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
    {
       int unit;
       double scal_width, scal_height;
@@ -1022,6 +1224,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       {
          pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
 
+         pngtest_check_text_support(read_ptr, text_ptr, num_text);
+
          if (verbose)
          {
             int i;
@@ -1047,10 +1251,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          png_set_tIME(write_ptr, write_info_ptr, mod_time);
 #ifdef PNG_TIME_RFC1123_SUPPORTED
          if (png_convert_to_rfc1123_buffer(tIME_string, mod_time))
-            tIME_string[png_sizeof(tIME_string) - 1] = '\0';
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
 
          else
-            strcpy(tIME_string, "*** invalid time ***");
+         {
+            strncpy(tIME_string, "*** invalid time ***", (sizeof tIME_string));
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
+         }
 
          tIME_chunk_present++;
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
@@ -1087,16 +1294,20 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 
       if (num_unknowns)
       {
-         int i;
          png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns,
            num_unknowns);
+#if PNG_LIBPNG_VER < 10600
          /* Copy the locations from the read_info_ptr.  The automatically
-          * generated locations in write_info_ptr are wrong because we
-          * haven't written anything yet.
+          * generated locations in write_end_info_ptr are wrong prior to 1.6.0
+          * because they are reset from the write pointer (removed in 1.6.0).
           */
-         for (i = 0; i < num_unknowns; i++)
-           png_set_unknown_chunk_location(write_ptr, write_info_ptr, i,
-             unknowns[i].location);
+         {
+            int i;
+            for (i = 0; i < num_unknowns; i++)
+              png_set_unknown_chunk_location(write_ptr, write_info_ptr, i,
+                unknowns[i].location);
+         }
+#endif
       }
    }
 #endif
@@ -1104,47 +1315,16 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_WRITE_SUPPORTED
    pngtest_debug("Writing info struct");
 
-/* If we wanted, we could write info in two steps:
- * png_write_info_before_PLTE(write_ptr, write_info_ptr);
- */
+   /* Write the info in two steps so that if we write the 'unknown' chunks here
+    * they go to the correct place.
+    */
+   png_write_info_before_PLTE(write_ptr, write_info_ptr);
+
+   write_chunks(write_ptr, before_PLTE); /* before PLTE */
+
    png_write_info(write_ptr, write_info_ptr);
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
-   if (user_chunk_data[0] != 0)
-   {
-      png_byte png_sTER[5] = {115,  84,  69,  82, '\0'};
-
-      unsigned char
-        ster_chunk_data[1];
-
-      if (verbose)
-         fprintf(STDERR, "\n stereo mode = %lu\n",
-           (unsigned long)(user_chunk_data[0] - 1));
-
-      ster_chunk_data[0]=(unsigned char)(user_chunk_data[0] - 1);
-      png_write_chunk(write_ptr, png_sTER, ster_chunk_data, 1);
-   }
-
-   if (user_chunk_data[1] != 0 || user_chunk_data[2] != 0)
-   {
-      png_byte png_vpAg[5] = {118, 112,  65, 103, '\0'};
-
-      unsigned char
-        vpag_chunk_data[9];
-
-      if (verbose)
-         fprintf(STDERR, " vpAg = %lu x %lu, units = %lu\n",
-           (unsigned long)user_chunk_data[1],
-           (unsigned long)user_chunk_data[2],
-           (unsigned long)user_chunk_data[3]);
-
-      png_save_uint_32(vpag_chunk_data, user_chunk_data[1]);
-      png_save_uint_32(vpag_chunk_data + 4, user_chunk_data[2]);
-      vpag_chunk_data[8] = (unsigned char)(user_chunk_data[3] & 0xff);
-      png_write_chunk(write_ptr, png_vpAg, vpag_chunk_data, 9);
-   }
-
-#endif
+   write_chunks(write_ptr, before_IDAT); /* after PLTE */
 #endif
 
 #ifdef SINGLE_ROWBUF_ALLOC
@@ -1209,11 +1389,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-   png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
-#endif
-#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-   png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#  ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+      png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
+#  endif
+#  ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+      png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#  endif
 #endif
 
    pngtest_debug("Reading and writing end_info data");
@@ -1228,6 +1410,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       {
          pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
 
+         pngtest_check_text_support(read_ptr, text_ptr, num_text);
+
          if (verbose)
          {
             int i;
@@ -1253,10 +1437,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          png_set_tIME(write_ptr, write_end_info_ptr, mod_time);
 #ifdef PNG_TIME_RFC1123_SUPPORTED
          if (png_convert_to_rfc1123_buffer(tIME_string, mod_time))
-            tIME_string[png_sizeof(tIME_string) - 1] = '\0';
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
 
          else
-            strcpy(tIME_string, "*** invalid time ***");
+         {
+            strncpy(tIME_string, "*** invalid time ***", sizeof tIME_string);
+            tIME_string[(sizeof tIME_string)-1] = '\0';
+         }
 
          tIME_chunk_present++;
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
@@ -1271,20 +1458,41 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 
       if (num_unknowns)
       {
-         int i;
          png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns,
            num_unknowns);
+#if PNG_LIBPNG_VER < 10600
          /* Copy the locations from the read_info_ptr.  The automatically
-          * generated locations in write_end_info_ptr are wrong because we
-          * haven't written the end_info yet.
+          * generated locations in write_end_info_ptr are wrong prior to 1.6.0
+          * because they are reset from the write pointer (removed in 1.6.0).
           */
-         for (i = 0; i < num_unknowns; i++)
-           png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i,
-             unknowns[i].location);
+         {
+            int i;
+            for (i = 0; i < num_unknowns; i++)
+              png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i,
+                unknowns[i].location);
+         }
+#endif
       }
    }
 #endif
+
 #ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   /* Normally one would use Z_DEFAULT_STRATEGY for text compression.
+    * This is here just to make pngtest replicate the results from libpng
+    * versions prior to 1.5.4, and to test this new API.
+    */
+   png_set_text_compression_strategy(write_ptr, Z_FILTERED);
+#endif
+
+   /* When the unknown vpAg/sTER chunks are written by pngtest the only way to
+    * do it is to write them *before* calling png_write_end.  When unknown
+    * chunks are written by libpng, however, they are written just before IEND.
+    * There seems to be no way round this, however vpAg/sTER are not expected
+    * after IDAT.
+    */
+   write_chunks(write_ptr, after_IDAT);
+
    png_write_end(write_ptr, write_end_info_ptr);
 #endif
 
@@ -1318,6 +1526,40 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    FCLOSE(fpin);
    FCLOSE(fpout);
 
+   /* Summarize any warnings or errors and in 'strict' mode fail the test.
+    * Unsupported chunks can result in warnings, in that case ignore the strict
+    * setting, otherwise fail the test on warnings as well as errors.
+    */
+   if (error_count > 0)
+   {
+      /* We don't really expect to get here because of the setjmp handling
+       * above, but this is safe.
+       */
+      fprintf(STDERR, "\n  %s: %d libpng errors found (%d warnings)",
+         inname, error_count, warning_count);
+
+      if (strict != 0)
+         return (1);
+   }
+
+#  ifdef PNG_WRITE_SUPPORTED
+      /* If there we no write support nothing was written! */
+      else if (unsupported_chunks > 0)
+      {
+         fprintf(STDERR, "\n  %s: unsupported chunks (%d)%s",
+            inname, unsupported_chunks, strict ? ": IGNORED --strict!" : "");
+      }
+#  endif
+
+   else if (warning_count > 0)
+   {
+      fprintf(STDERR, "\n  %s: %d libpng warnings found",
+         inname, warning_count);
+
+      if (strict != 0)
+         return (1);
+   }
+
    pngtest_debug("Opening files for comparison");
    if ((fpin = fopen(inname, "rb")) == NULL)
    {
@@ -1332,71 +1574,83 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       return (1);
    }
 
-   for (;;)
+#ifdef PNG_WRITE_SUPPORTED /* else nothing was written */
    {
-      png_size_t num_in, num_out;
-
-         num_in = fread(inbuf, 1, 1, fpin);
-         num_out = fread(outbuf, 1, 1, fpout);
-
-      if (num_in != num_out)
+      for (;;)
       {
-         fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
-                 inname, outname);
+         static int wrote_question = 0;
+         png_size_t num_in, num_out;
+         char inbuf[256], outbuf[256];
 
-         if (wrote_question == 0)
+         num_in = fread(inbuf, 1, sizeof inbuf, fpin);
+         num_out = fread(outbuf, 1, sizeof outbuf, fpout);
+
+         if (num_in != num_out)
          {
-            fprintf(STDERR,
-         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
-              inname, PNG_ZBUF_SIZE);
-            fprintf(STDERR,
-              "\n   filtering heuristic (libpng default), compression");
-            fprintf(STDERR,
-              " level (zlib default),\n   and zlib version (%s)?\n\n",
-              ZLIB_VERSION);
-            wrote_question = 1;
-         }
+            fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
+                    inname, outname);
 
-         FCLOSE(fpin);
-         FCLOSE(fpout);
-
-         if (strict != 0)
-           return (1);
-
-         else
-           return (0);
-      }
-
-      if (!num_in)
-         break;
-
-      if (memcmp(inbuf, outbuf, num_in))
-      {
-         fprintf(STDERR, "\nFiles %s and %s are different\n", inname, outname);
-
-         if (wrote_question == 0)
-         {
-            fprintf(STDERR,
+            if (wrote_question == 0 && unsupported_chunks == 0)
+            {
+               fprintf(STDERR,
          "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
                  inname, PNG_ZBUF_SIZE);
-            fprintf(STDERR,
-              "\n   filtering heuristic (libpng default), compression");
-            fprintf(STDERR,
-              " level (zlib default),\n   and zlib version (%s)?\n\n",
-              ZLIB_VERSION);
-            wrote_question = 1;
+               fprintf(STDERR,
+                 "\n   filtering heuristic (libpng default), compression");
+               fprintf(STDERR,
+                 " level (zlib default),\n   and zlib version (%s)?\n\n",
+                 ZLIB_VERSION);
+               wrote_question = 1;
+            }
+
+            FCLOSE(fpin);
+            FCLOSE(fpout);
+
+            if (strict != 0 && unsupported_chunks == 0)
+              return (1);
+
+            else
+              return (0);
          }
 
-         FCLOSE(fpin);
-         FCLOSE(fpout);
+         if (!num_in)
+            break;
 
-         if (strict != 0)
-           return (1);
+         if (memcmp(inbuf, outbuf, num_in))
+         {
+            fprintf(STDERR, "\nFiles %s and %s are different\n", inname,
+               outname);
 
-         else
-           return (0);
+            if (wrote_question == 0 && unsupported_chunks == 0)
+            {
+               fprintf(STDERR,
+         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+                    inname, PNG_ZBUF_SIZE);
+               fprintf(STDERR,
+                 "\n   filtering heuristic (libpng default), compression");
+               fprintf(STDERR,
+                 " level (zlib default),\n   and zlib version (%s)?\n\n",
+                 ZLIB_VERSION);
+               wrote_question = 1;
+            }
+
+            FCLOSE(fpin);
+            FCLOSE(fpout);
+
+            /* NOTE: the unsupported_chunks escape is permitted here because
+             * unsupported text chunk compression will result in the compression
+             * mode being changed (to NONE) yet, in the test case, the result
+             * can be exactly the same size!
+             */
+            if (strict != 0 && unsupported_chunks == 0)
+              return (1);
+
+            else
+              return (0);
+         }
       }
    }
+#endif /* PNG_WRITE_SUPPORTED */
 
    FCLOSE(fpin);
    FCLOSE(fpout);
@@ -1482,6 +1736,16 @@ main(int argc, char *argv[])
          verbose = 1;
          inname = argv[2];
          strict++;
+         relaxed = 0;
+      }
+
+      else if (strcmp(argv[1], "--relaxed") == 0)
+      {
+         status_dots_requested = 0;
+         verbose = 1;
+         inname = argv[2];
+         strict = 0;
+         relaxed++;
       }
 
       else
@@ -1690,6 +1954,16 @@ main(int argc, char *argv[])
 
    return (int)(ierror != 0);
 }
+#else
+int
+main(void)
+{
+   fprintf(STDERR,
+      " test ignored because libpng was not built with read support\n");
+   /* And skip this test */
+   return 77;
+}
+#endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_0beta24 Your_png_h_is_not_version_1_6_0beta24;
+typedef png_libpng_version_1_7_0beta24 Your_png_h_is_not_version_1_7_0beta24;

pngtrans.c

@@ -1,8 +1,8 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -57,7 +57,9 @@ png_set_packing(png_structrp png_ptr)
    if (png_ptr->bit_depth < 8)
    {
       png_ptr->transformations |= PNG_PACK;
-      png_ptr->usr_bit_depth = 8;
+#     ifdef PNG_WRITE_SUPPORTED
+         png_ptr->usr_bit_depth = 8;
+#     endif
    }
 }
 #endif
@@ -122,32 +124,79 @@ png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
    if (png_ptr == NULL)
       return;
 
+   /* In libpng 1.6 it is possible to determine whether this is a read or write
+    * operation and therefore to do more checking here for a valid call.
+    */
+   if (png_ptr->mode & PNG_IS_READ_STRUCT)
+   {
+#     ifdef PNG_READ_FILLER_SUPPORTED
+         /* On read png_set_filler is always valid, regardless of the base PNG
+          * format, because other transformations can give a format where the
+          * filler code can execute (basically an 8 or 16-bit component RGB or G
+          * format.)
+          *
+          * NOTE: usr_channels is not used by the read code!  (This has led to
+          * confusion in the past.)  The filler is only used in the read code.
+          */
+         png_ptr->filler = (png_uint_16)filler;
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on read");
+         PNG_UNUSED(filler) /* not used in the write case */
+         return;
+#     endif
+   }
+
+   else /* write */
+   {
+#     ifdef PNG_WRITE_FILLER_SUPPORTED
+         /* On write the usr_channels parameter must be set correctly at the
+          * start to record the number of channels in the app-supplied data.
+          */
+         switch (png_ptr->color_type)
+         {
+            case PNG_COLOR_TYPE_RGB:
+               png_ptr->usr_channels = 4;
+               break;
+
+            case PNG_COLOR_TYPE_GRAY:
+               if (png_ptr->bit_depth >= 8)
+               {
+                  png_ptr->usr_channels = 2;
+                  break;
+               }
+
+               else
+               {
+                  /* There simply isn't any code in libpng to strip out bits
+                   * from bytes when the components are less than a byte in
+                   * size!
+                   */
+                  png_app_error(png_ptr,
+                     "png_set_filler is invalid for low bit depth gray output");
+                  return;
+               }
+
+            default:
+               png_app_error(png_ptr,
+                  "png_set_filler: inappropriate color type");
+               return;
+         }
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on write");
+         return;
+#     endif
+   }
+
+   /* Here on success - libpng supports the operation, set the transformation
+    * and the flag to say where the filler channel is.
+    */
    png_ptr->transformations |= PNG_FILLER;
-   png_ptr->filler = (png_uint_16)filler;
 
    if (filler_loc == PNG_FILLER_AFTER)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
 
    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
-
-   /* This should probably go in the "do_read_filler" routine.
-    * I attempted to do that in libpng-1.0.1a but that caused problems
-    * so I restored it in libpng-1.0.2a
-   */
-
-   if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
-   {
-      png_ptr->usr_channels = 4;
-   }
-
-   /* Also I added this in libpng-1.0.2a (what happens when we expand
-    * a less-than-8-bit grayscale to GA?) */
-
-   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
-   {
-      png_ptr->usr_channels = 2;
-   }
 }
 
 /* Added to libpng-1.2.7 */
@@ -160,7 +209,9 @@ png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
       return;
 
    png_set_filler(png_ptr, filler, filler_loc);
-   png_ptr->transformations |= PNG_ADD_ALPHA;
+   /* The above may fail to do anything. */
+   if (png_ptr->transformations & PNG_FILLER)
+      png_ptr->transformations |= PNG_ADD_ALPHA;
 }
 
 #endif
@@ -733,6 +784,17 @@ png_set_user_transform_info(png_structrp png_ptr, png_voidp
 
    if (png_ptr == NULL)
       return;
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+      (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+   {
+      png_app_error(png_ptr,
+            "info change after png_start_read_image or png_read_update_info");
+      return;
+   }
+#endif
+
    png_ptr->user_transform_ptr = user_transform_ptr;
    png_ptr->user_transform_depth = (png_byte)user_transform_depth;
    png_ptr->user_transform_channels = (png_byte)user_transform_channels;

pngwio.c

@@ -1,8 +1,8 @@
 
 /* pngwio.c - functions for data output
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -149,8 +149,11 @@ png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
 #  else
    png_ptr->output_flush_fn = output_flush_fn;
 #  endif
+#else
+   PNG_UNUSED(output_flush_fn)
 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
 
+#ifdef PNG_READ_SUPPORTED
    /* It is an error to read while writing a png file */
    if (png_ptr->read_data_fn != NULL)
    {
@@ -160,5 +163,6 @@ png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
           "Can't set both read_data_fn and write_data_fn in the"
           " same structure");
    }
+#endif
 }
 #endif /* PNG_WRITE_SUPPORTED */

pngwrite.c

@@ -1,8 +1,8 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -12,12 +12,65 @@
  */
 
 #include "pngpriv.h"
-#if defined PNG_SIMPLIFIED_WRITE_SUPPORTED && defined PNG_STDIO_SUPPORTED
+#if defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
 #  include <errno.h>
 #endif
 
 #ifdef PNG_WRITE_SUPPORTED
 
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+/* Write out all the unknown chunks for the current given location */
+static void
+write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
+   unsigned int where)
+{
+   if (info_ptr->unknown_chunks_num)
+   {
+      png_const_unknown_chunkp up;
+
+      png_debug(5, "writing extra chunks");
+
+      for (up = info_ptr->unknown_chunks;
+           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+           ++up)
+         if (up->location & where)
+      {
+         /* If per-chunk unknown chunk handling is enabled use it, otherwise
+          * just write the chunks the application has set.
+          */
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+         int keep = png_handle_as_unknown(png_ptr, up->name);
+
+         /* NOTE: this code is radically different from the read side in the
+          * matter of handling an ancillary unknown chunk.  In the read side
+          * the default behavior is to discard it, in the code below the default
+          * behavior is to write it.  Critical chunks are, however, only
+          * written if explicitly listed or if the default is set to write all
+          * unknown chunks.
+          *
+          * The default handling is also slightly weird - it is not possible to
+          * stop the writing of all unsafe-to-copy chunks!
+          *
+          * TODO: REVIEW: this would seem to be a bug.
+          */
+         if (keep != PNG_HANDLE_CHUNK_NEVER &&
+             ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ ||
+              keep == PNG_HANDLE_CHUNK_ALWAYS ||
+              (keep == PNG_HANDLE_CHUNK_AS_DEFAULT &&
+               png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS)))
+#endif
+         {
+            /* TODO: review, what is wrong with a zero length unknown chunk? */
+            if (up->size == 0)
+               png_warning(png_ptr, "Writing zero-length unknown chunk");
+
+            png_write_chunk(png_ptr, up->name, up->data, up->size);
+         }
+      }
+   }
+}
+#endif /* PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED */
+
 /* Writes all the PNG information.  This is the suggested way to use the
  * library.  If you have a new chunk to add, make a function to write it,
  * and put it in the correct location here.  If you want the chunk written
@@ -54,10 +107,12 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
        info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
        info_ptr->filter_type,
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
-       info_ptr->interlace_type);
+       info_ptr->interlace_type
 #else
-       0);
+       0
 #endif
+      );
+
    /* The rest of these check to see if the valid field has the appropriate
     * flag set, and if it does, writes the chunk.
     *
@@ -125,34 +180,9 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
 #endif
 
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-   if (info_ptr->unknown_chunks_num)
-   {
-      png_unknown_chunk *up;
-
-      png_debug(5, "writing extra chunks");
-
-      for (up = info_ptr->unknown_chunks;
-           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
-           up++)
-      {
-         int keep = png_handle_as_unknown(png_ptr, up->name);
-
-         if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location &&
-             !(up->location & PNG_HAVE_PLTE) &&
-             !(up->location & PNG_HAVE_IDAT) &&
-             !(up->location & PNG_AFTER_IDAT) &&
-             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
-             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
-         {
-            if (up->size == 0)
-               png_warning(png_ptr, "Writing zero-length unknown chunk");
-
-            png_write_chunk(png_ptr, up->name, up->data, up->size);
-         }
-      }
-   }
+      write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR);
 #endif
+
       png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
    }
 }
@@ -186,8 +216,13 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
       if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
           info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       {
-         int j;
-         for (j = 0; j<(int)info_ptr->num_trans; j++)
+         int j, jend;
+
+         jend = info_ptr->num_trans;
+         if (jend > PNG_MAX_PALETTE_LENGTH)
+            jend = PNG_MAX_PALETTE_LENGTH;
+
+         for (j = 0; j<jend; ++j)
             info_ptr->trans_alpha[j] =
                (png_byte)(255 - info_ptr->trans_alpha[j]);
       }
@@ -302,29 +337,7 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
 #endif /* tEXt */
 
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-   if (info_ptr->unknown_chunks_num)
-   {
-      png_unknown_chunk *up;
-
-      png_debug(5, "writing extra chunks");
-
-      for (up = info_ptr->unknown_chunks;
-           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
-           up++)
-      {
-         int keep = png_handle_as_unknown(png_ptr, up->name);
-         if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location &&
-             (up->location & PNG_HAVE_PLTE) &&
-             !(up->location & PNG_HAVE_IDAT) &&
-             !(up->location & PNG_AFTER_IDAT) &&
-             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
-             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
-         {
-            png_write_chunk(png_ptr, up->name, up->data, up->size);
-         }
-      }
-   }
+   write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE);
 #endif
 }
 
@@ -416,27 +429,7 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
       }
 #endif
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-   if (info_ptr->unknown_chunks_num)
-   {
-      png_unknown_chunk *up;
-
-      png_debug(5, "writing extra chunks");
-
-      for (up = info_ptr->unknown_chunks;
-           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
-           up++)
-      {
-         int keep = png_handle_as_unknown(png_ptr, up->name);
-         if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location &&
-             (up->location & PNG_AFTER_IDAT) &&
-             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
-             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
-         {
-            png_write_chunk(png_ptr, up->name, up->data, up->size);
-         }
-      }
-   }
+      write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
 #endif
    }
 
@@ -459,7 +452,6 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
 }
 
 #ifdef PNG_CONVERT_tIME_SUPPORTED
-/* "tm" structure is not supported on WindowsCE */
 void PNGAPI
 png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime)
 {
@@ -508,46 +500,50 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
       error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
 #endif /* PNG_USER_MEM_SUPPORTED */
 
-   /* Set the zlib control values to defaults; they can be overridden by the
-    * application after the struct has been created.
-    */
-   png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
+   if (png_ptr != NULL)
+   {
+      /* Set the zlib control values to defaults; they can be overridden by the
+       * application after the struct has been created.
+       */
+      png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
 
-   png_ptr->zlib_strategy = Z_FILTERED; /* may be overridden if no filters */
-   png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
-   png_ptr->zlib_mem_level = 8;
-   png_ptr->zlib_window_bits = 15;
-   png_ptr->zlib_method = 8;
+      /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
+       * pngwutil.c defaults it according to whether or not filters will be
+       * used, and ignores this setting.
+       */
+      png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
+      png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
+      png_ptr->zlib_mem_level = 8;
+      png_ptr->zlib_window_bits = 15;
+      png_ptr->zlib_method = 8;
 
 #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
-   png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;
-   png_ptr->zlib_text_level = Z_DEFAULT_COMPRESSION;
-   png_ptr->zlib_text_mem_level = 8;
-   png_ptr->zlib_text_window_bits = 15;
-   png_ptr->zlib_text_method = 8;
+      png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
+      png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
+      png_ptr->zlib_text_mem_level = 8;
+      png_ptr->zlib_text_window_bits = 15;
+      png_ptr->zlib_text_method = 8;
 #endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
 
-   /* This is a highly dubious configuration option; by default it is off, but
-    * it may be appropriate for private builds that are testing extensions not
-    * conformant to the current specification, or of applications that must not
-    * fail to write at all costs!
-    */
-#  ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
+      /* This is a highly dubious configuration option; by default it is off,
+       * but it may be appropriate for private builds that are testing
+       * extensions not conformant to the current specification, or of
+       * applications that must not fail to write at all costs!
+       */
+#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
       png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
       /* In stable builds only warn if an application error can be completely
        * handled.
        */
-#  endif
+#endif
 
-   /* App warnings are warnings in release (or release candidate) builds but
-    * are errors during development.
-    */
-#  if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
-      png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
-#  endif
+      /* App warnings are warnings in release (or release candidate) builds but
+       * are errors during development.
+       */
+#if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+         png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
+#endif
 
-   if (png_ptr != NULL)
-   {
       /* TODO: delay this, it can be done in png_init_io() (if the app doesn't
        * do it itself) avoiding setting the default function if it is not
        * required.
@@ -617,6 +613,71 @@ png_write_image(png_structrp png_ptr, png_bytepp image)
    }
 }
 
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Performs intrapixel differencing  */
+static void
+png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_intrapixel");
+
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      int bytes_per_pixel;
+      png_uint_32 row_width = row_info->width;
+      if (row_info->bit_depth == 8)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 3;
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 4;
+
+         else
+            return;
+
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            *(rp)     = (png_byte)((*rp       - *(rp + 1)) & 0xff);
+            *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff);
+         }
+      }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 6;
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 8;
+
+         else
+            return;
+
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            png_uint_32 s0   = (*(rp    ) << 8) | *(rp + 1);
+            png_uint_32 s1   = (*(rp + 2) << 8) | *(rp + 3);
+            png_uint_32 s2   = (*(rp + 4) << 8) | *(rp + 5);
+            png_uint_32 red  = (png_uint_32)((s0 - s1) & 0xffffL);
+            png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
+            *(rp    ) = (png_byte)((red >> 8) & 0xff);
+            *(rp + 1) = (png_byte)(red & 0xff);
+            *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
+            *(rp + 5) = (png_byte)(blue & 0xff);
+         }
+      }
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
+   }
+}
+#endif /* PNG_MNG_FEATURES_SUPPORTED */
+
 /* Called by user to write a row of image data */
 void PNGAPI
 png_write_row(png_structrp png_ptr, png_const_bytep row)
@@ -762,7 +823,7 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
    png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
 
    /* Copy user's row into buffer, leaving room for filter byte. */
-   png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
+   memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Handle interlacing */
@@ -858,7 +919,7 @@ png_write_flush(png_structrp png_ptr)
 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-static void png_reset_filter_heuristics(png_structrp png_ptr); /* forward decl */
+static void png_reset_filter_heuristics(png_structrp png_ptr);/* forward decl */
 #endif
 
 /* Free any memory used in png_ptr struct without freeing the struct itself. */
@@ -889,7 +950,7 @@ png_write_destroy(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->inv_filter_costs);
 #endif
 
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
    png_free(png_ptr, png_ptr->chunk_list);
 #endif
 
@@ -939,41 +1000,52 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
    if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
        (method == PNG_INTRAPIXEL_DIFFERENCING))
       method = PNG_FILTER_TYPE_BASE;
-
 #endif
-   if (method == PNG_FILTER_TYPE_BASE)
-   {
-      switch (filters & (PNG_ALL_FILTERS | 0x07))
+
+   /* The only supported method, except for the check above, is
+    * PNG_FILTER_TYPE_BASE.  The code below does not use 'method' other than
+    * for the check, so just keep going if png_app_error returns.
+    */
+   if (method != PNG_FILTER_TYPE_BASE)
+      png_app_error(png_ptr, "Unknown custom filter method");
+
+   /* If filter writing is not supported the 'filters' value must be zero,
+    * otherwise the value must be a single, valid, filter value or a set of the
+    * mask values.  The defines in png.h are such that the filter masks used in
+    * this API and internally are 1<<(3+value), value is in the range 0..4, so
+    * this fits in a byte.
+    */
+#  ifdef PNG_WRITE_FILTER_SUPPORTED
+      /* Notice that PNG_NO_FILTERS is 0 and passes this test; this is OK
+       * because filters then gets set to PNG_FILTER_NONE, as is required.
+       */
+      if (filters < PNG_FILTER_VALUE_LAST)
+         filters = 0x08 << filters;
+
+      else if ((filters & ~PNG_ALL_FILTERS) != 0)
       {
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-         case 5:
-         case 6:
-         case 7: png_warning(png_ptr, "Unknown row filter for method 0");
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
-         case PNG_FILTER_VALUE_NONE:
-            png_ptr->do_filter = PNG_FILTER_NONE; break;
+         png_app_error(png_ptr, "png_set_filter: invalid filters mask/value");
 
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-         case PNG_FILTER_VALUE_SUB:
-            png_ptr->do_filter = PNG_FILTER_SUB; break;
+         /* For compatibility with the previous behavior assume a mask value was
+          * passed and ignore the non-mask bits.
+          */
+         filters &= PNG_ALL_FILTERS;
 
-         case PNG_FILTER_VALUE_UP:
-            png_ptr->do_filter = PNG_FILTER_UP; break;
-
-         case PNG_FILTER_VALUE_AVG:
-            png_ptr->do_filter = PNG_FILTER_AVG; break;
-
-         case PNG_FILTER_VALUE_PAETH:
-            png_ptr->do_filter = PNG_FILTER_PAETH; break;
-
-         default:
-            png_ptr->do_filter = (png_byte)filters; break;
-#else
-         default:
-            png_warning(png_ptr, "Unknown row filter for method 0");
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
+         /* For a possibly foolish consistency (it shouldn't matter) set
+          * PNG_FILTER_NONE rather than 0.
+          */
+         if (filters == 0)
+            filters = PNG_FILTER_NONE;
       }
+#  else
+      /* PNG_FILTER_VALUE_NONE and PNG_NO_FILTERS are both 0. */
+      if (filters != 0 && filters != PNG_FILTER_NONE)
+         png_app_error(png_ptr, "png_set_filter: no filters supported");
 
+      filters = PNG_FILTER_NONE;
+#  endif
+
+#  ifdef PNG_WRITE_FILTER_SUPPORTED
       /* If we have allocated the row_buf, this means we have already started
        * with the image and we should have allocated all of the filter buffers
        * that have been selected.  If prev_row isn't already allocated, then
@@ -982,75 +1054,45 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
        * wants to start and stop using particular filters during compression,
        * it should start out with all of the filters, and then add and
        * remove them after the start of compression.
+       *
+       * NOTE: this is a nasty constraint on the code, because it means that the
+       * prev_row buffer must be maintained even if there are currently no
+       * 'prev_row' requiring filters active.
        */
       if (png_ptr->row_buf != NULL)
       {
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-         if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
+         /* Repeat the checks in png_write_start_row; 1 pixel high or wide
+          * images cannot benefit from certain filters.  If this isn't done here
+          * the check below will fire on 1 pixel high images.
+          */
+         if (png_ptr->height == 1)
+            filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+         if (png_ptr->width == 1)
+            filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+         if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0
+            && png_ptr->prev_row == NULL)
          {
-            png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
-                (png_ptr->rowbytes + 1));
-            png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
+            /* This is the error case, however it is benign - the previous row
+             * is not available so the filter can't be used.  Just warn here.
+             */
+            png_app_warning(png_ptr,
+               "png_set_filter: UP/AVG/PAETH cannot be added after start");
+            filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
          }
 
-         if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
-         {
-            if (png_ptr->prev_row == NULL)
-            {
-               png_warning(png_ptr, "Can't add Up filter after starting");
-               png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
-                   ~PNG_FILTER_UP);
-            }
-
-            else
-            {
-               png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
-                   (png_ptr->rowbytes + 1));
-               png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
-            }
-         }
-
-         if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
-         {
-            if (png_ptr->prev_row == NULL)
-            {
-               png_warning(png_ptr, "Can't add Average filter after starting");
-               png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
-                   ~PNG_FILTER_AVG);
-            }
-
-            else
-            {
-               png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
-                   (png_ptr->rowbytes + 1));
-               png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
-            }
-         }
-
-         if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
-             png_ptr->paeth_row == NULL)
-         {
-            if (png_ptr->prev_row == NULL)
-            {
-               png_warning(png_ptr, "Can't add Paeth filter after starting");
-               png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
-            }
-
-            else
-            {
-               png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
-                   (png_ptr->rowbytes + 1));
-               png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
-            }
-         }
-
-         if (png_ptr->do_filter == PNG_NO_FILTERS)
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
-            png_ptr->do_filter = PNG_FILTER_NONE;
+         /* Allocate any required buffers that have not already been allocated.
+          */
+         png_write_alloc_filter_row_buffers(png_ptr, filters);
       }
-   }
-   else
-      png_error(png_ptr, "Unknown custom filter method");
+#  endif /* PNG_WRITE_FILTER_SUPPORTED */
+
+   /* Finally store the value.
+    * TODO: this field could probably be removed if neither READ nor
+    * WRITE_FILTER are supported.
+    */
+   png_ptr->do_filter = (png_byte)filters; /* SAFE: checked above */
 }
 
 /* This allows us to influence the way in which libpng chooses the "best"
@@ -1116,7 +1158,7 @@ png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method,
       if (num_weights > 0)
       {
          png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_byte) * num_weights));
+             (png_uint_32)((sizeof (png_byte)) * num_weights));
 
          /* To make sure that the weighting starts out fairly */
          for (i = 0; i < num_weights; i++)
@@ -1125,10 +1167,10 @@ png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method,
          }
 
          png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+             (png_uint_32)((sizeof (png_uint_16)) * num_weights));
 
          png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+             (png_uint_32)((sizeof (png_uint_16)) * num_weights));
 
          for (i = 0; i < num_weights; i++)
          {
@@ -1146,10 +1188,10 @@ png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method,
       if (png_ptr->filter_costs == NULL)
       {
          png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+             (png_uint_32)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST));
 
          png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+             (png_uint_32)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST));
       }
 
       for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
@@ -1347,7 +1389,7 @@ png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
    /* Prior to 1.6.0 this would warn but then set the window_bits value, this
     * meant that negative window bits values could be selected which would cause
     * libpng to write a non-standard PNG file with raw deflate or gzip
-    * compressed IDAT or ancilliary chunks.  Such files can be read and there is
+    * compressed IDAT or ancillary chunks.  Such files can be read and there is
     * no warning on read, so this seems like a very bad idea.
     */
    if (window_bits > 15)
@@ -1586,11 +1628,11 @@ png_image_write_init(png_imagep image)
       if (info_ptr != NULL)
       {
          png_controlp control = png_voidcast(png_controlp,
-            png_malloc_warn(png_ptr, sizeof *control));
+            png_malloc_warn(png_ptr, (sizeof *control)));
 
          if (control != NULL)
          {
-            png_memset(control, 0, sizeof *control);
+            memset(control, 0, (sizeof *control));
 
             control->png_ptr = png_ptr;
             control->info_ptr = info_ptr;
@@ -1607,7 +1649,7 @@ png_image_write_init(png_imagep image)
       png_destroy_write_struct(&png_ptr, NULL);
    }
 
-   return png_image_error(image, "png_image_read: out of memory");
+   return png_image_error(image, "png_image_write_: out of memory");
 }
 
 /* Arguments to png_image_write_main: */
@@ -1647,14 +1689,16 @@ png_write_image_16bit(png_voidp argument)
 
    if (image->format & PNG_FORMAT_FLAG_ALPHA)
    {
-      if (image->format & PNG_FORMAT_FLAG_AFIRST)
-      {
-         aindex = -1;
-         ++input_row; /* To point to the first component */
-         ++output_row;
-      }
+#     ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+         if (image->format & PNG_FORMAT_FLAG_AFIRST)
+         {
+            aindex = -1;
+            ++input_row; /* To point to the first component */
+            ++output_row;
+         }
 
-      else
+         else
+#     endif
          aindex = channels;
    }
 
@@ -1803,14 +1847,16 @@ png_write_image_8bit(png_voidp argument)
       png_bytep row_end;
       int aindex;
 
-      if (image->format & PNG_FORMAT_FLAG_AFIRST)
-      {
-         aindex = -1;
-         ++input_row; /* To point to the first component */
-         ++output_row;
-      }
+#     ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+         if (image->format & PNG_FORMAT_FLAG_AFIRST)
+         {
+            aindex = -1;
+            ++input_row; /* To point to the first component */
+            ++output_row;
+         }
 
-      else
+         else
+#     endif
          aindex = channels;
 
       /* Use row_end in place of a loop counter: */
@@ -1890,7 +1936,8 @@ png_image_set_PLTE(png_image_write_control *display)
    const png_uint_32 format = image->format;
    const int channels = PNG_IMAGE_SAMPLE_CHANNELS(format);
 
-#  ifdef PNG_FORMAT_BGR_SUPPORTED
+#  if defined(PNG_FORMAT_BGR_SUPPORTED) &&\
+      defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED)
       const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
          (format & PNG_FORMAT_FLAG_ALPHA) != 0;
 #  else
@@ -1907,8 +1954,8 @@ png_image_set_PLTE(png_image_write_control *display)
    png_color palette[256];
    png_byte tRNS[256];
 
-   memset(tRNS, 255, sizeof tRNS);
-   memset(palette, 0, sizeof palette);
+   memset(tRNS, 255, (sizeof tRNS));
+   memset(palette, 0, (sizeof palette));
 
    for (i=num_trans=0; i<entries; ++i)
    {
@@ -2154,7 +2201,7 @@ png_image_write_main(png_voidp argument)
       ptrdiff_t row_bytes = display->row_stride;
 
       if (linear)
-         row_bytes *= sizeof (png_uint_16);
+         row_bytes *= (sizeof (png_uint_16));
 
       if (row_bytes < 0)
          row += (image->height-1) * (-row_bytes);
@@ -2224,7 +2271,7 @@ png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
    const void *buffer, png_int_32 row_stride, const void *colormap)
 {
    /* Write the image to the given (FILE*). */
-   if (image != NULL || image->version != PNG_IMAGE_VERSION)
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
    {
       if (file != NULL)
       {
@@ -2239,7 +2286,7 @@ png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
              */
             image->opaque->png_ptr->io_ptr = file;
 
-            png_memset(&display, 0, sizeof display);
+            memset(&display, 0, (sizeof display));
             display.image = image;
             display.buffer = buffer;
             display.row_stride = row_stride;
@@ -2260,6 +2307,10 @@ png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
             "png_image_write_to_stdio: invalid argument");
    }
 
+   else if (image != NULL)
+      return png_image_error(image,
+         "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
+
    else
       return 0;
 }
@@ -2270,7 +2321,7 @@ png_image_write_to_file(png_imagep image, const char *file_name,
    const void *colormap)
 {
    /* Write the image to the named file. */
-   if (image != NULL || image->version != PNG_IMAGE_VERSION)
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
    {
       if (file_name != NULL)
       {
@@ -2323,6 +2374,10 @@ png_image_write_to_file(png_imagep image, const char *file_name,
             "png_image_write_to_file: invalid argument");
    }
 
+   else if (image != NULL)
+      return png_image_error(image,
+         "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
+
    else
       return 0;
 }

pngwtran.c

@@ -1,8 +1,8 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -14,90 +14,14 @@
 #include "pngpriv.h"
 
 #ifdef PNG_WRITE_SUPPORTED
-
 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
-/* Transform the data according to the user's wishes.  The order of
- * transformations is significant.
- */
-void /* PRIVATE */
-png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
-{
-   png_debug(1, "in png_do_write_transformations");
-
-   if (png_ptr == NULL)
-      return;
-
-#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
-   if (png_ptr->transformations & PNG_USER_TRANSFORM)
-      if (png_ptr->write_user_transform_fn != NULL)
-         (*(png_ptr->write_user_transform_fn)) /* User write transform
-                                                 function */
-             (png_ptr,  /* png_ptr */
-             row_info,  /* row_info: */
-                /*  png_uint_32 width;       width of row */
-                /*  png_size_t rowbytes;     number of bytes in row */
-                /*  png_byte color_type;     color type of pixels */
-                /*  png_byte bit_depth;      bit depth of samples */
-                /*  png_byte channels;       number of channels (1-4) */
-                /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
-             png_ptr->row_buf + 1);      /* start of pixel data for row */
-#endif
-
-#ifdef PNG_WRITE_FILLER_SUPPORTED
-   if (png_ptr->transformations & PNG_FILLER)
-      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
-         !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
-#endif
-
-#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
-   if (png_ptr->transformations & PNG_PACKSWAP)
-      png_do_packswap(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_PACK_SUPPORTED
-   if (png_ptr->transformations & PNG_PACK)
-      png_do_pack(row_info, png_ptr->row_buf + 1,
-          (png_uint_32)png_ptr->bit_depth);
-#endif
-
-#ifdef PNG_WRITE_SWAP_SUPPORTED
-   if (png_ptr->transformations & PNG_SWAP_BYTES)
-      png_do_swap(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_SHIFT_SUPPORTED
-   if (png_ptr->transformations & PNG_SHIFT)
-      png_do_shift(row_info, png_ptr->row_buf + 1,
-          &(png_ptr->shift));
-#endif
-
-#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
-   if (png_ptr->transformations & PNG_SWAP_ALPHA)
-      png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
-   if (png_ptr->transformations & PNG_INVERT_ALPHA)
-      png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_BGR_SUPPORTED
-   if (png_ptr->transformations & PNG_BGR)
-      png_do_bgr(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_WRITE_INVERT_SUPPORTED
-   if (png_ptr->transformations & PNG_INVERT_MONO)
-      png_do_invert(row_info, png_ptr->row_buf + 1);
-#endif
-}
 
 #ifdef PNG_WRITE_PACK_SUPPORTED
 /* Pack pixels into bytes.  Pass the true bit depth in bit_depth.  The
  * row_info bit depth should be 8 (one pixel per byte).  The channels
  * should be 1 (this only happens on grayscale and paletted images).
  */
-void /* PRIVATE */
+static void
 png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
 {
    png_debug(1, "in png_do_pack");
@@ -242,7 +166,7 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
  * would pass 3 as bit_depth, and this routine would translate the
  * data to 0 to 15.
  */
-void /* PRIVATE */
+static void
 png_do_shift(png_row_infop row_info, png_bytep row,
     png_const_color_8p bit_depth)
 {
@@ -381,7 +305,7 @@ png_do_shift(png_row_infop row_info, png_bytep row,
 #endif
 
 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
-void /* PRIVATE */
+static void
 png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_write_swap_alpha");
@@ -475,7 +399,7 @@ png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
 #endif
 
 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
-void /* PRIVATE */
+static void
 png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_write_invert_alpha");
@@ -568,70 +492,81 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
    }
 }
 #endif
-#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
 
-#ifdef PNG_MNG_FEATURES_SUPPORTED
-/* Undoes intrapixel differencing  */
+/* Transform the data according to the user's wishes.  The order of
+ * transformations is significant.
+ */
 void /* PRIVATE */
-png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
+png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
 {
-   png_debug(1, "in png_do_write_intrapixel");
+   png_debug(1, "in png_do_write_transformations");
 
-   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
-   {
-      int bytes_per_pixel;
-      png_uint_32 row_width = row_info->width;
-      if (row_info->bit_depth == 8)
-      {
-         png_bytep rp;
-         png_uint_32 i;
+   if (png_ptr == NULL)
+      return;
 
-         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
-            bytes_per_pixel = 3;
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   if (png_ptr->transformations & PNG_USER_TRANSFORM)
+      if (png_ptr->write_user_transform_fn != NULL)
+         (*(png_ptr->write_user_transform_fn)) /* User write transform
+                                                 function */
+             (png_ptr,  /* png_ptr */
+             row_info,  /* row_info: */
+                /*  png_uint_32 width;       width of row */
+                /*  png_size_t rowbytes;     number of bytes in row */
+                /*  png_byte color_type;     color type of pixels */
+                /*  png_byte bit_depth;      bit depth of samples */
+                /*  png_byte channels;       number of channels (1-4) */
+                /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
+             png_ptr->row_buf + 1);      /* start of pixel data for row */
+#endif
 
-         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
-            bytes_per_pixel = 4;
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+   if (png_ptr->transformations & PNG_FILLER)
+      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+         !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
+#endif
 
-         else
-            return;
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+   if (png_ptr->transformations & PNG_PACKSWAP)
+      png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
 
-         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
-         {
-            *(rp)     = (png_byte)((*rp       - *(rp + 1)) & 0xff);
-            *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff);
-         }
-      }
+#ifdef PNG_WRITE_PACK_SUPPORTED
+   if (png_ptr->transformations & PNG_PACK)
+      png_do_pack(row_info, png_ptr->row_buf + 1,
+          (png_uint_32)png_ptr->bit_depth);
+#endif
 
-#ifdef PNG_WRITE_16BIT_SUPPORTED
-      else if (row_info->bit_depth == 16)
-      {
-         png_bytep rp;
-         png_uint_32 i;
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+   if (png_ptr->transformations & PNG_SWAP_BYTES)
+      png_do_swap(row_info, png_ptr->row_buf + 1);
+#endif
 
-         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
-            bytes_per_pixel = 6;
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+   if (png_ptr->transformations & PNG_SHIFT)
+      png_do_shift(row_info, png_ptr->row_buf + 1,
+          &(png_ptr->shift));
+#endif
 
-         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
-            bytes_per_pixel = 8;
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+   if (png_ptr->transformations & PNG_SWAP_ALPHA)
+      png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
 
-         else
-            return;
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+   if (png_ptr->transformations & PNG_INVERT_ALPHA)
+      png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
 
-         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
-         {
-            png_uint_32 s0   = (*(rp    ) << 8) | *(rp + 1);
-            png_uint_32 s1   = (*(rp + 2) << 8) | *(rp + 3);
-            png_uint_32 s2   = (*(rp + 4) << 8) | *(rp + 5);
-            png_uint_32 red  = (png_uint_32)((s0 - s1) & 0xffffL);
-            png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
-            *(rp    ) = (png_byte)((red >> 8) & 0xff);
-            *(rp + 1) = (png_byte)(red & 0xff);
-            *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
-            *(rp + 5) = (png_byte)(blue & 0xff);
-         }
-      }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
-   }
+#ifdef PNG_WRITE_BGR_SUPPORTED
+   if (png_ptr->transformations & PNG_BGR)
+      png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+   if (png_ptr->transformations & PNG_INVERT_MONO)
+      png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
 }
-#endif /* PNG_MNG_FEATURES_SUPPORTED */
+#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
 #endif /* PNG_WRITE_SUPPORTED */

pngwutil.c

@@ -1,8 +1,8 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -29,23 +29,6 @@ png_save_uint_32(png_bytep buf, png_uint_32 i)
    buf[3] = (png_byte)(i & 0xff);
 }
 
-#ifdef PNG_SAVE_INT_32_SUPPORTED
-/* The png_save_int_32 function assumes integers are stored in two's
- * complement format.  If this isn't the case, then this routine needs to
- * be modified to write data in two's complement format.  Note that,
- * the following works correctly even if png_int_32 has more than 32 bits
- * (compare the more complex code required on read for sign extention.)
- */
-void PNGAPI
-png_save_int_32(png_bytep buf, png_int_32 i)
-{
-   buf[0] = (png_byte)((i >> 24) & 0xff);
-   buf[1] = (png_byte)((i >> 16) & 0xff);
-   buf[2] = (png_byte)((i >> 8) & 0xff);
-   buf[3] = (png_byte)(i & 0xff);
-}
-#endif
-
 /* Place a 16-bit number into a buffer in PNG byte order.
  * The parameter is declared unsigned int, not png_uint_16,
  * just to avoid potential problems on pre-ANSI C compilers.
@@ -235,18 +218,18 @@ png_image_size(png_structrp png_ptr)
           */
          png_uint_32 w = png_ptr->width;
          unsigned int pd = png_ptr->pixel_depth;
-         png_alloc_size_t cbBase;
+         png_alloc_size_t cb_base;
          int pass;
 
-         for (cbBase=0, pass=0; pass<=6; ++pass)
+         for (cb_base=0, pass=0; pass<=6; ++pass)
          {
             png_uint_32 pw = PNG_PASS_COLS(w, pass);
 
             if (pw > 0)
-               cbBase += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
+               cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
          }
 
-         return cbBase;
+         return cb_base;
       }
 
       else
@@ -324,7 +307,7 @@ png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
        * internal error, but is very useful for debugging.  i18n requirements
        * are minimal.
        */
-      (void)png_safecat(msg, sizeof msg, 10, " using zstream");
+      (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
 #     if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
          png_warning(png_ptr, msg);
 
@@ -355,10 +338,10 @@ png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
             strategy = png_ptr->zlib_strategy;
 
          else if (png_ptr->do_filter != PNG_FILTER_NONE)
-            strategy = Z_FILTERED;
+            strategy = PNG_Z_DEFAULT_STRATEGY;
 
          else
-            strategy = Z_DEFAULT_STRATEGY;
+            strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;
       }
 
       else
@@ -452,6 +435,27 @@ png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
    }
 }
 
+/* Clean up (or trim) a linked list of compression buffers. */
+void /* PRIVATE */
+png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
+{
+   png_compression_bufferp list = *listp;
+
+   if (list != NULL)
+   {
+      *listp = NULL;
+
+      do
+      {
+         png_compression_bufferp next = list->next;
+
+         png_free(png_ptr, list);
+         list = next;
+      }
+      while (list != NULL);
+   }
+}
+
 #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
 /* This pair of functions encapsulates the operation of (a) compressing a
  * text string, and (b) issuing it later as a series of chunk data writes.
@@ -480,26 +484,6 @@ png_text_compress_init(compression_state *comp, png_const_bytep input,
    comp->output_len = 0;
 }
 
-void /* PRIVATE */
-png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
-{
-   png_compression_bufferp list = *listp;
-
-   if (list != NULL)
-   {
-      *listp = NULL;
-
-      do
-      {
-         png_compression_bufferp next = list->next;
-
-         png_free(png_ptr, list);
-         list = next;
-      }
-      while (list != NULL);
-   }
-}
-
 /* Compress the data in the compression state input */
 static int
 png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
@@ -537,7 +521,7 @@ png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
       png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
       png_ptr->zstream.avail_in = 0; /* Set below */
       png_ptr->zstream.next_out = comp->output;
-      png_ptr->zstream.avail_out = sizeof comp->output;
+      png_ptr->zstream.avail_out = (sizeof comp->output);
 
       output_len = png_ptr->zstream.avail_out;
 
@@ -654,7 +638,7 @@ png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
 {
    png_uint_32 output_len = comp->output_len;
    png_const_bytep output = comp->output;
-   png_uint_32 avail = sizeof comp->output;
+   png_uint_32 avail = (sizeof comp->output);
    png_compression_buffer *next = png_ptr->zbuffer_list;
 
    for (;;)
@@ -676,7 +660,7 @@ png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
 
    /* This is an internal error; 'next' must have been NULL! */
    if (output_len > 0)
-      png_error(png_ptr, "error writing ancilliary chunked compressed data");
+      png_error(png_ptr, "error writing ancillary chunked compressed data");
 }
 #endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
 
@@ -707,7 +691,7 @@ png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
       *new_key = 0;
       return 0;
    }
-   
+
    while (*key && key_len < 79)
    {
       png_byte ch = (png_byte)(0xff & *key++);
@@ -1025,6 +1009,8 @@ png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
    {
       /* First time.   Ensure we have a temporary buffer for compression and
        * trim the buffer list if it has more than one entry to free memory.
+       * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
+       * created at this point, but the check here is quick and safe.
        */
       if (png_ptr->zbuffer_list == NULL)
       {
@@ -1439,14 +1425,17 @@ png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
 
    if (color_type == PNG_COLOR_TYPE_PALETTE)
    {
-      if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
+      if (num_trans <= 0 || num_trans > png_ptr->num_palette)
       {
-         png_warning(png_ptr, "Invalid number of transparent colors specified");
+         /* This is an error which can only be reliably detected late. */
+         png_app_error(png_ptr,
+            "Invalid number of transparent colors specified");
          return;
       }
 
       /* Write the chunk out as it is */
-      png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans);
+      png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
+         (png_size_t)num_trans);
    }
 
    else if (color_type == PNG_COLOR_TYPE_GRAY)
@@ -1454,7 +1443,8 @@ png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
       /* One 16 bit value */
       if (tran->gray >= (1 << png_ptr->bit_depth))
       {
-         png_warning(png_ptr,
+         /* This can no longer happen because it is checked in png_set_tRNS */
+         png_app_error(png_ptr,
              "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
 
          return;
@@ -1476,7 +1466,8 @@ png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
       if (buf[0] | buf[2] | buf[4])
 #endif
       {
-         png_warning(png_ptr,
+         /* Also checked in png_set_tRNS */
+         png_app_error(png_ptr,
            "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
          return;
       }
@@ -1486,7 +1477,8 @@ png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
 
    else
    {
-      png_warning(png_ptr, "Can't write tRNS with an alpha channel");
+      /* Checked in png_set_tRNS */
+      png_app_error(png_ptr, "Can't write tRNS with an alpha channel");
    }
 }
 #endif
@@ -1604,7 +1596,7 @@ png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
       text_len = 0;
 
    else
-      text_len = png_strlen(text);
+      text_len = strlen(text);
 
    if (text_len > PNG_UINT_31_MAX - (key_len+1))
       png_error(png_ptr, "tEXt: text too long");
@@ -1638,7 +1630,7 @@ png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
    compression_state comp;
 
    png_debug(1, "in png_write_zTXt");
-   PNG_UNUSED(text_len); /* Always use strlen */
+   PNG_UNUSED(text_len) /* Always use strlen */
 
    if (compression == PNG_TEXT_COMPRESSION_NONE)
    {
@@ -1693,7 +1685,7 @@ png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
    png_debug(1, "in png_write_iTXt");
 
    key_len = png_check_keyword(png_ptr, key, new_key);
-   
+
    if (key_len == 0)
       png_error(png_ptr, "iTXt: invalid keyword");
 
@@ -1756,6 +1748,9 @@ png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
    {
       if (comp.input_len > PNG_UINT_31_MAX-prefix_len)
          png_error(png_ptr, "iTXt: uncompressed text too long");
+
+      /* So the string will fit in a chunk: */
+      comp.output_len = (png_uint_32)/*SAFE*/comp.input_len;
    }
 
    png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len);
@@ -1770,7 +1765,7 @@ png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
       png_write_compressed_data_out(png_ptr, &comp);
 
    else
-      png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.input_len);
+      png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len);
 
    png_write_chunk_end(png_ptr);
 }
@@ -1819,23 +1814,23 @@ png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
 
    if (purpose_len == 0)
       png_error(png_ptr, "pCAL: invalid keyword");
-   
+
    ++purpose_len; /* terminator */
 
    png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
-   units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
+   units_len = strlen(units) + (nparams == 0 ? 0 : 1);
    png_debug1(3, "pCAL units length = %d", (int)units_len);
    total_len = purpose_len + units_len + 10;
 
    params_len = (png_size_tp)png_malloc(png_ptr,
-       (png_alloc_size_t)(nparams * png_sizeof(png_size_t)));
+       (png_alloc_size_t)(nparams * (sizeof (png_size_t))));
 
    /* Find the length of each parameter, making sure we don't count the
     * null terminator for the last parameter.
     */
    for (i = 0; i < nparams; i++)
    {
-      params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
+      params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
       png_debug2(3, "pCAL parameter %d length = %lu", i,
           (unsigned long)params_len[i]);
       total_len += params_len[i];
@@ -1872,8 +1867,8 @@ png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
 
    png_debug(1, "in png_write_sCAL_s");
 
-   wlen = png_strlen(width);
-   hlen = png_strlen(height);
+   wlen = strlen(width);
+   hlen = strlen(height);
    total_len = wlen + hlen + 2;
 
    if (total_len > 64)
@@ -1883,8 +1878,8 @@ png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
    }
 
    buf[0] = (png_byte)unit;
-   png_memcpy(buf + 1, width, wlen + 1);      /* Append the '\0' here */
-   png_memcpy(buf + wlen + 2, height, hlen);  /* Do NOT append the '\0' here */
+   memcpy(buf + 1, width, wlen + 1);      /* Append the '\0' here */
+   memcpy(buf + wlen + 2, height, hlen);  /* Do NOT append the '\0' here */
 
    png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
    png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
@@ -1943,6 +1938,47 @@ png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)
 }
 #endif
 
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+void /* PRIVATE */
+png_write_alloc_filter_row_buffers(png_structrp png_ptr, int filters)
+   /* Allocate row buffers for any filters that need them, this is also called
+    * from png_set_filter if the filters are changed during write to ensure that
+    * the required buffers exist.  png_set_filter ensures that up/avg/paeth are
+    * only set if png_ptr->prev_row is allocated.
+    */
+{
+   /* The buffer size is determined just by the output row size, not any
+    * processing requirements.
+    */
+   png_alloc_size_t buf_size = png_ptr->rowbytes + 1;
+
+   if ((filters & PNG_FILTER_SUB) != 0 && png_ptr->sub_row == NULL)
+   {
+      png_ptr->sub_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+      png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
+   }
+
+   if ((filters & PNG_FILTER_UP) != 0 && png_ptr->up_row == NULL)
+   {
+      png_ptr->up_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+      png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
+   }
+
+   if ((filters & PNG_FILTER_AVG) != 0 && png_ptr->avg_row == NULL)
+   {
+      png_ptr->avg_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+      png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
+   }
+
+   if ((filters & PNG_FILTER_PAETH) != 0 && png_ptr->paeth_row == NULL)
+   {
+      png_ptr->paeth_row = png_voidcast(png_bytep, png_malloc(png_ptr,
+         buf_size));
+      png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
+   }
+}
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+
 /* Initializes the row writing capability of libpng */
 void /* PRIVATE */
 png_write_start_row(png_structrp png_ptr)
@@ -1963,11 +1999,18 @@ png_write_start_row(png_structrp png_ptr)
    static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
 #endif
 
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   int filters;
+#endif
+
    png_alloc_size_t buf_size;
    int usr_pixel_depth;
 
    png_debug(1, "in png_write_start_row");
 
+   if (png_ptr == NULL)
+      return;
+
    usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
    buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
 
@@ -1976,49 +2019,34 @@ png_write_start_row(png_structrp png_ptr)
    png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
 
    /* Set up row buffer */
-   png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size);
+   png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
 
    png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
 
 #ifdef PNG_WRITE_FILTER_SUPPORTED
-   /* Set up filtering buffer, if using this filter */
-   if (png_ptr->do_filter & PNG_FILTER_SUB)
-   {
-      png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
+   filters = png_ptr->do_filter;
 
-      png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
-   }
+   if (png_ptr->height == 1)
+      filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
 
-   /* We only need to keep the previous row if we are using one of these. */
-   if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
-   {
-      /* Set up previous row buffer */
-      png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size);
+   if (png_ptr->width == 1)
+      filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
 
-      if (png_ptr->do_filter & PNG_FILTER_UP)
-      {
-         png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
-            png_ptr->rowbytes + 1);
+   if (filters == 0)
+      filters = PNG_FILTER_NONE;
 
-         png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
-      }
+   /* We only need to keep the previous row if we are using one of the following
+    * filters.
+    */
+   if (filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
+      png_ptr->prev_row = png_voidcast(png_bytep, png_calloc(png_ptr,
+         buf_size));
 
-      if (png_ptr->do_filter & PNG_FILTER_AVG)
-      {
-         png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
-             png_ptr->rowbytes + 1);
+   png_write_alloc_filter_row_buffers(png_ptr, filters);
 
-         png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
-      }
-
-      if (png_ptr->do_filter & PNG_FILTER_PAETH)
-      {
-         png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
-             png_ptr->rowbytes + 1);
-
-         png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
-      }
-   }
+   png_ptr->do_filter = (png_byte)filters; /* in case it was changed above */
+#else
+   png_ptr->do_filter = PNG_FILTER_NONE;
 #endif /* PNG_WRITE_FILTER_SUPPORTED */
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
@@ -2119,7 +2147,7 @@ png_write_finish_row(png_structrp png_ptr)
       if (png_ptr->pass < 7)
       {
          if (png_ptr->prev_row != NULL)
-            png_memset(png_ptr->prev_row, 0,
+            memset(png_ptr->prev_row, 0,
                 (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
                 png_ptr->usr_bit_depth, png_ptr->width)) + 1);
 
@@ -2294,7 +2322,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
 
                /* Move the pixel */
                if (dp != sp)
-                  png_memcpy(dp, sp, pixel_bytes);
+                  memcpy(dp, sp, pixel_bytes);
 
                /* Next pixel */
                dp += pixel_bytes;
@@ -3006,6 +3034,7 @@ png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
 
    png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH);
 
+#ifdef PNG_WRITE_FILTER_SUPPORTED
    /* Swap the current and previous rows */
    if (png_ptr->prev_row != NULL)
    {
@@ -3015,6 +3044,7 @@ png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
       png_ptr->prev_row = png_ptr->row_buf;
       png_ptr->row_buf = tptr;
    }
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
 
    /* Finish row - updates counters and flushes zlib if last row */
    png_write_finish_row(png_ptr);

projects/visualc71/libpng.vcproj

@@ -30,7 +30,7 @@
 				Name="VCCustomBuildTool"/>
 			<Tool
 				Name="VCLinkerTool"
-				OutputFile="$(OutDir)/libpng16.dll"
+				OutputFile="$(OutDir)/libpng17.dll"
 				LinkIncremental="1"/>
 			<Tool
 				Name="VCMIDLTool"/>
@@ -78,7 +78,7 @@
 				Name="VCCustomBuildTool"/>
 			<Tool
 				Name="VCLinkerTool"
-				OutputFile="$(OutDir)/libpng16d.dll"
+				OutputFile="$(OutDir)/libpng17d.dll"
 				GenerateDebugInformation="TRUE"/>
 			<Tool
 				Name="VCMIDLTool"/>
@@ -126,7 +126,7 @@
 				Name="VCCustomBuildTool"/>
 			<Tool
 				Name="VCLinkerTool"
-				OutputFile="$(OutDir)/libpng16vb.dll"
+				OutputFile="$(OutDir)/libpng17vb.dll"
 				LinkIncremental="1"/>
 			<Tool
 				Name="VCMIDLTool"/>

projects/visualc71/pngtest.vcproj

@@ -130,7 +130,7 @@ $(TargetPath) ..\..\pngtest.png $(IntDir)\pngout.png"
 				Name="VCLinkerTool"
 				OutputFile="$(OutDir)/pngtest.exe"
 				LinkIncremental="1"
-				IgnoreDefaultLibraryNames="$(IntDir)\libpng16b.lib"
+				IgnoreDefaultLibraryNames="$(IntDir)\libpng17b.lib"
 				SubSystem="1"
 				TargetMachine="1"/>
 			<Tool

projects/vstudio/WARNING

@@ -0,0 +1,27 @@
+WARNING
+=======
+Libpng 1.6 does not use the default run-time library when building static
+library builds of libpng; instead of the shared DLL runtime it uses a static
+runtime.  If you need to change this make sure to change the setting on all the
+relevant projects:
+
+libpng
+zlib
+all the test programs
+
+The runtime library settings for each build are as follows:
+
+           Release        Debug
+DLL         /MD            /MDd
+Library     /MT            /MTd
+
+NOTICE that libpng 1.5 erroneously used /MD for Debug DLL builds; if you used
+the debug builds in your app and you changed your app to use /MD you will need
+to change it to /MDd for libpng 1.6.
+
+The Visual Studio 2010 defaults for a Win32 DLL or Static Library project are
+as follows:
+
+                 Release     Debug
+DLL               /MD         /MDd
+Static Library    /MD         /MDd

projects/vstudio/libpng/libpng.vcxproj

@@ -23,8 +23,8 @@
     <Keyword>Win32Proj</Keyword>
     <RootNamespace>libpng</RootNamespace>
   </PropertyGroup>
-  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
     <CharacterSet>MultiByte</CharacterSet>
@@ -63,23 +63,23 @@
     <LinkIncremental>false</LinkIncremental>
     <CustomBuildBeforeTargets>
     </CustomBuildBeforeTargets>
-    <TargetName>$(ProjectName)16</TargetName>
+    <TargetName>$(ProjectName)17</TargetName>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
     <LinkIncremental>false</LinkIncremental>
     <CustomBuildBeforeTargets />
-    <TargetName>$(ProjectName)16</TargetName>
+    <TargetName>$(ProjectName)17</TargetName>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <LinkIncremental>false</LinkIncremental>
     <CustomBuildBeforeTargets>
     </CustomBuildBeforeTargets>
-    <TargetName>$(ProjectName)16</TargetName>
+    <TargetName>$(ProjectName)17</TargetName>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
     <LinkIncremental>false</LinkIncremental>
     <CustomBuildBeforeTargets />
-    <TargetName>$(ProjectName)16</TargetName>
+    <TargetName>$(ProjectName)17</TargetName>
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
@@ -101,12 +101,13 @@
       <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
       <Optimization>Disabled</Optimization>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
       <SubSystem>Windows</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <AdditionalDependencies>zlib.lib</AdditionalDependencies>
-      <Version>16</Version>
+      <Version>17</Version>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
   </ItemDefinitionGroup>
@@ -163,7 +164,7 @@
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <AdditionalDependencies>zlib.lib</AdditionalDependencies>
-      <Version>16</Version>
+      <Version>17</Version>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
   </ItemDefinitionGroup>

projects/vstudio/pnglibconf/pnglibconf.vcxproj

@@ -17,6 +17,7 @@
     <WholeProgramOptimization>true</WholeProgramOptimization>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>
+  <Import Project="$(SolutionDir)\zlib.props" />
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>

projects/vstudio/pngstest/pngstest.vcxproj

@@ -19,12 +19,12 @@
     </ProjectConfiguration>
   </ItemGroup>
   <PropertyGroup Label="Globals">
-    <ProjectGuid>{9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}</ProjectGuid>
+    <ProjectGuid>{277AC57F-313B-4D06-B119-A3CDB672D2FF}</ProjectGuid>
     <Keyword>Win32Proj</Keyword>
     <RootNamespace>pngstest</RootNamespace>
   </PropertyGroup>
-  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <CharacterSet>Unicode</CharacterSet>
@@ -91,11 +91,12 @@
       <FunctionLevelLinking>false</FunctionLevelLinking>
       <BrowseInformation>true</BrowseInformation>
       <FloatingPointExceptions>false</FloatingPointExceptions>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
     <CustomBuildStep>
@@ -128,7 +129,7 @@
     <Link>
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
     <CustomBuildStep>
@@ -162,7 +163,7 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
       <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
     </Link>
@@ -198,7 +199,7 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
       <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
     </Link>

projects/vstudio/pngtest/pngtest.vcxproj

@@ -23,8 +23,8 @@
     <Keyword>Win32Proj</Keyword>
     <RootNamespace>pngtest</RootNamespace>
   </PropertyGroup>
-  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <CharacterSet>Unicode</CharacterSet>
@@ -91,11 +91,12 @@
       <FunctionLevelLinking>false</FunctionLevelLinking>
       <BrowseInformation>true</BrowseInformation>
       <FloatingPointExceptions>false</FloatingPointExceptions>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>libpng16.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
     <CustomBuildStep>
@@ -128,7 +129,7 @@
     <Link>
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
     <CustomBuildStep>
@@ -163,7 +164,7 @@
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
-      <AdditionalDependencies>libpng16.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
     <CustomBuildStep>
@@ -198,7 +199,7 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
       <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>

projects/vstudio/pngunknown/pngunknown.vcxproj

@@ -0,0 +1,219 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug Library|Win32">
+      <Configuration>Debug Library</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release Library|Win32">
+      <Configuration>Release Library</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}</ProjectGuid>
+    <Keyword>Win32Proj</Keyword>
+    <RootNamespace>pngunknown</RootNamespace>
+  </PropertyGroup>
+  <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" />
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <LinkIncremental>false</LinkIncremental>
+    <CustomBuildAfterTargets />
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
+    <LinkIncremental>false</LinkIncremental>
+    <CustomBuildAfterTargets />
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <LinkIncremental>false</LinkIncremental>
+    <CustomBuildAfterTargets />
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
+    <LinkIncremental>false</LinkIncremental>
+    <CustomBuildAfterTargets />
+  </PropertyGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <MinimalRebuild>false</MinimalRebuild>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Disabled</Optimization>
+      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <CompileAsManaged>false</CompileAsManaged>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <StringPooling>true</StringPooling>
+      <FunctionLevelLinking>false</FunctionLevelLinking>
+      <BrowseInformation>true</BrowseInformation>
+      <FloatingPointExceptions>false</FloatingPointExceptions>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalDependencies>libpng17.lib</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
+    </Link>
+    <CustomBuildStep>
+      <Message>Executing PNG validation program</Message>
+      <Command>"$(OutDir)pngunknown.exe" --strict --default --touch "$(IntDir)pngunknown.out" ../../../pngtest.png</Command>
+      <Outputs>$(IntDir)pngunknown.out</Outputs>
+      <Inputs>$(OutDir)pngunknown.exe</Inputs>
+    </CustomBuildStep>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <MinimalRebuild>false</MinimalRebuild>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Disabled</Optimization>
+      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <CompileAsManaged>false</CompileAsManaged>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <StringPooling>true</StringPooling>
+      <FunctionLevelLinking>false</FunctionLevelLinking>
+      <BrowseInformation>true</BrowseInformation>
+      <FloatingPointExceptions>false</FloatingPointExceptions>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
+    </Link>
+    <CustomBuildStep>
+      <Message>Executing PNG validation program</Message>
+      <Command>"$(OutDir)pngunknown.exe" --strict --default --touch "$(IntDir)pngunknown.out" ../../../pngtest.png</Command>
+      <Outputs>$(IntDir)pngunknown.out</Outputs>
+      <Inputs>$(OutDir)pngunknown.exe</Inputs>
+    </CustomBuildStep>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Full</Optimization>
+      <FunctionLevelLinking>false</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <CompileAsManaged>false</CompileAsManaged>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <StringPooling>true</StringPooling>
+      <MinimalRebuild>false</MinimalRebuild>
+      <BrowseInformation>true</BrowseInformation>
+      <WholeProgramOptimization>true</WholeProgramOptimization>
+      <FloatingPointExceptions>false</FloatingPointExceptions>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalDependencies>libpng17.lib</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
+    </Link>
+    <CustomBuildStep>
+      <Message>Executing PNG validation program</Message>
+      <Command>"$(OutDir)pngunknown.exe" --strict --default --touch "$(IntDir)pngunknown.out" ../../../pngtest.png</Command>
+      <Outputs>$(IntDir)pngunknown.out</Outputs>
+      <Inputs>$(OutDir)pngunknown.exe</Inputs>
+    </CustomBuildStep>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Full</Optimization>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <FunctionLevelLinking>false</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <CompileAsManaged>false</CompileAsManaged>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <StringPooling>true</StringPooling>
+      <MinimalRebuild>false</MinimalRebuild>
+      <BrowseInformation>true</BrowseInformation>
+      <WholeProgramOptimization>true</WholeProgramOptimization>
+      <FloatingPointExceptions>false</FloatingPointExceptions>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
+    </Link>
+    <CustomBuildStep>
+      <Message>Executing PNG validation program</Message>
+      <Command>"$(OutDir)pngunknown.exe" --strict --default --touch "$(IntDir)pngunknown.out" ../../../pngtest.png</Command>
+      <Outputs>$(IntDir)pngunknown.out</Outputs>
+      <Inputs>$(OutDir)pngunknown.exe</Inputs>
+    </CustomBuildStep>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\..\contrib\libtests\pngunknown.c" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>

projects/vstudio/pngvalid/pngvalid.vcxproj

@@ -23,8 +23,8 @@
     <Keyword>Win32Proj</Keyword>
     <RootNamespace>pngvalid</RootNamespace>
   </PropertyGroup>
-  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <CharacterSet>Unicode</CharacterSet>
@@ -91,11 +91,12 @@
       <FunctionLevelLinking>false</FunctionLevelLinking>
       <BrowseInformation>true</BrowseInformation>
       <FloatingPointExceptions>false</FloatingPointExceptions>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
     <CustomBuildStep>
@@ -128,7 +129,7 @@
     <Link>
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
     <CustomBuildStep>
@@ -162,7 +163,7 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
       <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
     </Link>
@@ -198,7 +199,7 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
-      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalDependencies>libpng17.lib;zlib.lib</AdditionalDependencies>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
       <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
     </Link>

projects/vstudio/readme.txt

@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.6.0beta24 - June 7, 2012
+libpng version 1.7.0beta24 - December 15, 2013
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 
@@ -33,14 +33,14 @@ optimization level (e.g. /Od.)
 Linking your application
 ========================
 Normally you should link against the 'release' configuration.  This builds a
-DLL for libpng 1.5 with the default runtime options used by Visual Studio
-2010.  In particular the runtime library is the "MultiThreaded DLL" version.
+DLL for libpng with the default runtime options used by Visual Studio 2010.
+In particular the runtime library is the "MultiThreaded DLL" version.
 If you use Visual Studio defaults to build your application you will have no
 problems.
 
 If you don't use the Visual Studio defaults your application must still be built
 with the default runtime option (/MD).  If, for some reason, it is not then your
-application will crash inside libpng16.dll as soon as libpng tries to read
+application will crash inside libpng17.dll as soon as libpng tries to read
 from a file handle you pass in.
 
 If you do not want to use the DLL, for example for a very small application,
@@ -58,7 +58,8 @@ Debug versions have limited support
 This solution includes limited support for debug versions of libpng.  You
 do not need these unless your own solution itself uses debug builds (it is
 far more effective to debug on the release builds, there is no point building
-a special debug build.)
+a special debug build unless you have heap corruption problems that you can't
+track down.)
 
 The debug build of libpng is minimally supported.  Support for debug builds of
 zlib is also minimal.  You really don't want to do this.

projects/vstudio/vstudio.sln

@@ -1,5 +1,9 @@
 Microsoft Visual Studio Solution File, Format Version 11.00
 # Visual Studio 2010
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlib", "zlib\zlib.vcxproj", "{60F89955-91C6-3A36-8000-13C592FEC2DF}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pnglibconf", "pnglibconf\pnglibconf.vcxproj", "{EB33566E-DA7F-4D28-9077-88C0B7C77E35}"
+EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "libpng", "libpng\libpng.vcxproj", "{D6973076-9317-4EF2-A0B8-B7A18AC0713E}"
 	ProjectSection(ProjectDependencies) = postProject
 		{60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF}
@@ -13,8 +17,6 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngtest", "pngtest\pngtest.
 		{D6973076-9317-4EF2-A0B8-B7A18AC0713E} = {D6973076-9317-4EF2-A0B8-B7A18AC0713E}
 	EndProjectSection
 EndProject
-Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlib", "zlib\zlib.vcxproj", "{60F89955-91C6-3A36-8000-13C592FEC2DF}"
-EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngvalid", "pngvalid\pngvalid.vcxproj", "{9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}"
 	ProjectSection(ProjectDependencies) = postProject
 		{60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF}
@@ -22,8 +24,6 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngvalid", "pngvalid\pngval
 		{D6973076-9317-4EF2-A0B8-B7A18AC0713E} = {D6973076-9317-4EF2-A0B8-B7A18AC0713E}
 	EndProjectSection
 EndProject
-Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pnglibconf", "pnglibconf\pnglibconf.vcxproj", "{EB33566E-DA7F-4D28-9077-88C0B7C77E35}"
-EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngstest", "pngstest\pngstest.vcxproj", "{277AC57F-313B-4D06-B119-A3CDB672D2FF}"
 	ProjectSection(ProjectDependencies) = postProject
 		{60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF}
@@ -31,6 +31,13 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngstest", "pngstest\pngste
 		{D6973076-9317-4EF2-A0B8-B7A18AC0713E} = {D6973076-9317-4EF2-A0B8-B7A18AC0713E}
 	EndProjectSection
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngunknown", "pngunknown\pngunknown.vcxproj", "{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}"
+	ProjectSection(ProjectDependencies) = postProject
+		{60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF}
+		{EB33566E-DA7F-4D28-9077-88C0B7C77E35} = {EB33566E-DA7F-4D28-9077-88C0B7C77E35}
+		{D6973076-9317-4EF2-A0B8-B7A18AC0713E} = {D6973076-9317-4EF2-A0B8-B7A18AC0713E}
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug Library|Win32 = Debug Library|Win32
@@ -87,6 +94,14 @@ Global
 		{277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release Library|Win32.Build.0 = Release Library|Win32
 		{277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release|Win32.ActiveCfg = Release|Win32
 		{277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release|Win32.Build.0 = Release|Win32
+		{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}.Debug Library|Win32.ActiveCfg = Debug Library|Win32
+		{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}.Debug Library|Win32.Build.0 = Debug Library|Win32
+		{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}.Debug|Win32.Build.0 = Debug|Win32
+		{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}.Release Library|Win32.ActiveCfg = Release Library|Win32
+		{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}.Release Library|Win32.Build.0 = Release Library|Win32
+		{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}.Release|Win32.ActiveCfg = Release|Win32
+		{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}.Release|Win32.Build.0 = Release|Win32
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

projects/vstudio/zlib.props

@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.6.0beta24 - June 7, 2012
+ * libpng version 1.7.0beta24 - December 15, 2013
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *
@@ -33,5 +33,13 @@
 	 below:
      -->
     <ZLibSrcDir>..\..\..\..\zlib-1.2.5</ZLibSrcDir>
+
+    <!-- The following line allows compilation for an ARM target with Visual
+         Studio 2012.  Notice that this is not supported by the Visual Studio
+         2012 IDE and that the programs that result cannot be run unless they
+         signed by Microsoft.  This is therefore untested; only Microsoft can
+         test it:
+     -->
+    <WindowsSDKDesktopARMSupport>true</WindowsSDKDesktopARMSupport>
   </PropertyGroup>
 </Project>

projects/vstudio/zlib/zlib.vcxproj

@@ -32,10 +32,12 @@
     <ClCompile Include="$(ZLibSrcDir)\zutil.c" />
   </ItemGroup>
   <PropertyGroup Label="Globals">
+    <ProjectGuid>{60F89955-91C6-3A36-8000-13C592FEC2DF}</ProjectGuid>
     <Keyword>Win32Proj</Keyword>
+    <RootNamespace>zlib</RootNamespace>
   </PropertyGroup>
-  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'" Label="Configuration">
     <ConfigurationType>StaticLibrary</ConfigurationType>
   </PropertyGroup>
@@ -106,6 +108,7 @@
       <Optimization>Disabled</Optimization>
       <BrowseInformation>true</BrowseInformation>
       <FunctionLevelLinking>true</FunctionLevelLinking>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
       <TargetMachine>MachineX86</TargetMachine>

scripts/README.txt

@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.6.0beta24 - June 7, 2012
+Makefiles for  libpng version 1.7.0beta24 - December 15, 2013
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng16.so.16.1.6.0beta24)
+                       (gcc, creates libpng17.so.17.1.7.0beta24)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -20,7 +20,7 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.dec      =>  DEC Alpha UNIX makefile
  makefile.dj2      =>  DJGPP 2 makefile
  makefile.elf      =>  Linux/ELF makefile symbol versioning,
-                       (gcc, creates libpng16.so.16.1.6.0beta24)
+                       (gcc, creates libpng17.so.17.1.7.0beta24)
  makefile.freebsd  =>  FreeBSD makefile
  makefile.gcc      =>  Generic gcc makefile
  makefile.hpgcc    =>  HPUX makefile using gcc
@@ -35,12 +35,12 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
  makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
  makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng16.so.16.1.6.0beta24)
+                       creates libpng17.so.17.1.7.0beta24)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng16.so.16.1.6.0beta24)
+                       creates libpng17.so.17.1.7.0beta24)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng16.so.16.1.6.0beta24)
+                       creates libpng17.so.17.1.7.0beta24)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile

scripts/checksym.awk

@@ -113,6 +113,16 @@ END{
       err = 1
    }
    unexported=0
+   # Add a standard header to symbols.new:
+   print ";Version INSERT-VERSION-HERE" >of
+   print ";--------------------------------------------------------------" >of
+   print "; LIBPNG symbol list as a Win32 DEF file" >of
+   print "; Contains all the symbols that can be exported from libpng" >of
+   print ";--------------------------------------------------------------" >of
+   print "LIBRARY" >of
+   print "" >of
+   print "EXPORTS" >of
+
    for (o=1; o<=lasto; ++o) {
       if (symbol[o] == "" && removed[o] == "") {
          if (unexported == 0) unexported = o

scripts/def.dfn

@@ -8,31 +8,22 @@
  * and license in png.h
  */
 
-/* These macros exist to make the header and trailer shorter below: */
-#define S PNG_DEFN_MAGIC
-#define E PNG_DEFN_END
-
 /* Write the export file header: */
-S-;---------------------------------------------------------------E
-S-; LIBPNG module definition file for OS/2-E
-S-;---------------------------------------------------------------E
-S--E
-S-; If you give the library an explicit name one or other files-E
-S-; may need modifying to support the new name on one or more-E
-S-; systems.-E
-S-LIBRARY-E
-S-OS2 DESCRIPTION "PNG image compression library"-E
-S-OS2 CODE PRELOAD MOVEABLE DISCARDABLE-E
-S--E
-S-EXPORTS-E
-S-;Version 1.5.0beta58-E
+PNG_DFN ";--------------------------------------------------------------"
+PNG_DFN "; LIBPNG module definition file for OS/2"
+PNG_DFN ";--------------------------------------------------------------"
+PNG_DFN ""
+PNG_DFN "; If you give the library an explicit name one or other files"
+PNG_DFN "; may need modifying to support the new name on one or more"
+PNG_DFN "; systems."
+PNG_DFN "LIBRARY"
+PNG_DFN "OS2 DESCRIPTION "PNG image compression library""
+PNG_DFN "OS2 CODE PRELOAD MOVEABLE DISCARDABLE"
+PNG_DFN ""
+PNG_DFN "EXPORTS"
+PNG_DFN ";Version 1.7.0beta24"
 
-/* NOTE: PNG_JOIN is interpreted by the calling script as a signal to
- * join the two things on either side, so we can do symbol
- * substitution within the name, regular C ## joins the pp-tokens,
- * not their final values.
- */
 #define PNG_EXPORTA(ordinal, type, name, args, attributes)\
-	PNG_DEFN_MAGIC- SYMBOL_PREFIX PNG_JOIN name-PNG_DEFN_END
+        PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"
 
 #include "../png.h"

scripts/dfn.awk

@@ -0,0 +1,203 @@
+#!/bin/awk -f
+# scripts/dfn.awk - process a .dfn file
+#
+# last changed in libpng version 1.5.14 - February 4, 2013
+#
+# Copyright (c) 2013-2013 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# The output of this script is written to the file given by
+# the variable 'out', which should be set on the command line.
+# Error messages are printed to stdout and if any are printed
+# the script will exit with error code 1.
+
+BEGIN{
+   out="/dev/null"       # as a flag
+   out_count=0           # count of output lines
+   err=0                 # set if an error occured
+   sort=0                # sort the output
+   array[""]=""
+}
+
+# The output file must be specified before any input:
+NR==1 && out == "/dev/null" {
+   print "out=output.file must be given on the command line"
+   # but continue without setting the error code, this allows the
+   # script to be checked easily
+}
+
+# Output can be sorted; two lines are recognized
+$1 == "PNG_DFN_START_SORT"{
+   sort=0+$2
+   next
+}
+
+$1 ~ /^PNG_DFN_END_SORT/{
+   # Do a very simple, slow, sort; notice that blank lines won't be
+   # output by this
+   for (entry in array) {
+      while (array[entry] != "") {
+         key = entry
+         value = array[key]
+         array[key] = ""
+
+         for (alt in array) {
+            if (array[alt] != "" && alt < key) {
+               array[key] = value
+               value = array[alt]
+               key = alt
+               array[alt] = ""
+            }
+         }
+
+         print value >out
+      }
+   }
+   sort=0
+   next
+}
+
+/^[^"]*PNG_DFN *".*"[^"]*$/{
+   # A definition line, apparently correctly formated, extract the
+   # definition then replace any doubled "" that remain with a single
+   # double quote.  Notice that the original doubled double quotes
+   # may have been split by tokenization
+   #
+   # Sometimes GCC splits the PNG_DFN lines, we know this has happened
+   # if the quotes aren't closed and must read another line.  In this
+   # case it is essential to reject lines that start '#' because those
+   # are introduced #line directives.
+   orig=$0
+   line=$0
+   lineno=FNR
+   if (lineno == "") lineno=NR
+
+   if (sub(/^[^"]*PNG_DFN *"/,"",line) != 1) {
+	print "line", lineno ": processing failed:"
+	print orig
+	err=1
+       next
+   } else {
+	++out_count
+   }
+
+   # Now examine quotes within the value:
+   #
+   #   @" - delete this and any following spaces
+   #   "@ - delete this and any preceding spaces
+   #   @' - replace this by a double quote
+   #
+   # This allows macro substitution by the C compiler thus:
+   #
+   #   #define first_name John
+   #   #define last_name Smith
+   #
+   #	PNG_DFN"#define name @'@" first_name "@ @" last_name "@@'"
+   #
+   # Might get C preprocessed to:
+   #
+   #   PNG_DFN "#define foo @'@" John "@ @" Smith "@@'"
+   #
+   # Which this script reduces to:
+   #
+   #	#define name "John Smith"
+   #
+   while (1) {
+      # While there is an @" remove it and the next "@
+      if (line ~ /@"/) {
+         if (line ~ /@".*"@/) {
+            # Do this special case first to avoid swallowing extra spaces
+            # before or after the @ stuff:
+            if (!sub(/@" *"@/, "", line)) {
+               # Ok, do it in pieces - there has to be a non-space between the
+               # two.  NOTE: really weird things happen if a leading @" is
+               # lost - the code will error out below (I believe).
+               if (!sub(/@" */, "", line) || !sub(/ *"@/, "", line)) {
+                  print "line", lineno, ": internal error:", orig
+                  exit 1
+               }
+            }
+         }
+
+         # There is no matching "@.  Assume a split line
+         else while (1) {
+            if (getline nextline) {
+               # If the line starts with '#' it is a preprocesor line directive
+               # from cc -E, skip it:
+               if (nextline !~ /^#/) {
+                  line = line " " nextline
+                  break
+               }
+            } else {
+               # This is end-of-input - probably a missig "@ on the first line:
+               print "line", lineno ": unbalanced @\" ... \"@ pair"
+               err=1
+               next
+            }
+         }
+
+         # Keep going until all the @" have gone
+         continue
+      }
+
+      # Attempt to remove a trailing " (not preceded by '@') - if this can
+      # be done stop now, if not assume a split line again
+      if (sub(/"[^"]*$/, "", line))
+         break
+
+      # Read another line
+      while (1) {
+         if (getline nextline) {
+            if (nextline !~ /^#/) {
+               line = line " " nextline
+               # Go back to stripping @" "@ pairs
+               break
+            }
+         } else {
+            print "line", lineno ": unterminated PNG_DFN string"
+            err=1
+            next
+         }
+      }
+   }
+
+   # Put any needed double quotes in (at the end, because these would otherwise
+   # interfere with the processing above.)
+   gsub(/@'/,"\"", line)
+
+   # Remove any trailing spaces (not really required, but for
+   # editorial consistency
+   sub(/ *$/, "", line)
+
+   # Remove trailing CR
+   sub(/
+$/, "", line)
+
+   if (sort) {
+      if (split(line, parts) < sort) {
+         print "line", lineno ": missing sort field:", line
+         err=1
+      } else
+         array[parts[sort]] = line
+   }
+
+   else
+      print line >out
+   next
+}
+
+/PNG_DFN/{
+   print "line", NR, "incorrectly formated PNG_DFN line:"
+   print $0
+   err = 1
+}
+
+END{
+   if (out_count > 0 || err > 0)
+	exit err
+
+   print "no definition lines found"
+   exit 1

scripts/intprefix.dfn

@@ -10,10 +10,10 @@
  */
 
 #define PNG_INTERNAL_DATA(type, name, array)\
-	PNG_DEFN_MAGIC-name-PNG_DEFN_END
+        PNG_DFN "@" name "@"
 
 #define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
-	PNG_DEFN_MAGIC-name-PNG_DEFN_END
+        PNG_DFN "@" name "@"
 
 #define PNGPREFIX_H /* self generation */
 #include "../pngpriv.h"

scripts/libpng-config-head.in

@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.6.0beta24
+version=1.7.0beta24
 prefix=""
 libdir=""
 libs=""

scripts/libpng.pc.in

@@ -1,10 +1,10 @@
 prefix=@prefix@
 exec_prefix=@exec_prefix@
 libdir=@libdir@
-includedir=@includedir@/libpng16
+includedir=@includedir@/libpng17
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.6.0beta24
-Libs: -L${libdir} -lpng16
+Version: 1.7.0beta24
+Libs: -L${libdir} -lpng17
 Cflags: -I${includedir}

scripts/makefile.32sunu

@@ -9,8 +9,8 @@
 # and license in png.h
 
 # Library name:
-LIBNAME=libpng16
-PNGMAJ = 16
+LIBNAME=libpng17
+PNGMAJ = 17
 
 # Shared library names:
 LIBSO=$(LIBNAME).so
@@ -29,7 +29,7 @@ RM_F=/bin/rm -f
 SUN_CC_FLAGS=-fast -xtarget=ultra
 SUN_LD_FLAGS=-fast -xtarget=ultra
 
-# where make install puts libpng.a, libpng16.so and libpng16/png.h
+# where make install puts libpng.a, libpng17.so and libpng17/png.h
 prefix=/a
 exec_prefix=$(prefix)
 
@@ -95,7 +95,7 @@ libpng.pc:
 	-e s!@exec_prefix@!$(exec_prefix)! \
 	-e s!@libdir@!$(LIBPATH)! \
 	-e s!@includedir@!$(INCPATH)! \
-	-e s!-lpng16!-lpng16\ -lz\ -lm! > libpng.pc
+	-e s!-lpng17!-lpng17\ -lz\ -lm! > libpng.pc
 
 libpng-config:
 	( cat scripts/libpng-config-head.in; \
@@ -106,7 +106,7 @@ libpng-config:
 	echo R_opts=\"-R$(LIBPATH)\"; \
 	echo ccopts=\"-xtarget=ultra\"; \
 	echo ldopts=\"-xtarget=ultra\"; \
-	echo libs=\"-lpng16 -lz -lm\"; \
+	echo libs=\"-lpng17 -lz -lm\"; \
 	cat scripts/libpng-config-body.in ) > libpng-config
 	chmod +x libpng-config
 

scripts/makefile.64sunu

@@ -9,8 +9,8 @@
 # and license in png.h
 
 # Library name:
-LIBNAME=libpng16
-PNGMAJ = 16
+LIBNAME=libpng17
+PNGMAJ = 17
 
 # Shared library names:
 LIBSO=$(LIBNAME).so
@@ -29,7 +29,7 @@ RM_F=/bin/rm -f
 SUN_CC_FLAGS=-fast -xtarget=ultra -xarch=v9
 SUN_LD_FLAGS=-fast -xtarget=ultra -xarch=v9
 
-# where make install puts libpng.a, libpng16.so and libpng16/png.h
+# where make install puts libpng.a, libpng17.so and libpng17/png.h
 prefix=/a
 exec_prefix=$(prefix)
 
@@ -47,7 +47,7 @@ WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
 	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
 CFLAGS=-I$(ZLIBINC) $(SUN_CC_FLAGS) \
 	# $(WARNMORE) -g -DPNG_DEBUG=5
-LDFLAGS=-L. -R. $(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng16 -lz -lm
+LDFLAGS=-L. -R. $(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng17 -lz -lm
 
 INCPATH=$(prefix)/include
 LIBPATH=$(exec_prefix)/lib
@@ -95,7 +95,7 @@ libpng.pc:
 	-e s!@exec_prefix@!$(exec_prefix)! \
 	-e s!@libdir@!$(LIBPATH)! \
 	-e s!@includedir@!$(INCPATH)! \
-	-e s!-lpng16!-lpng16\ -lz\ -lm! > libpng.pc
+	-e s!-lpng17!-lpng17\ -lz\ -lm! > libpng.pc
 
 libpng-config:
 	( cat scripts/libpng-config-head.in; \
@@ -106,7 +106,7 @@ libpng-config:
 	echo R_opts=\"-R$(LIBPATH)\"; \
 	echo ccopts=\"-xtarget=ultra -xarch=v9\"; \
 	echo ldopts=\"-xtarget=ultra -xarch=v9\"; \
-	echo libs=\"-lpng16 -lz -lm\"; \
+	echo libs=\"-lpng17 -lz -lm\"; \
 	cat scripts/libpng-config-body.in ) > libpng-config
 	chmod +x libpng-config
 

scripts/makefile.aix

@@ -21,8 +21,8 @@ RANLIB = ranlib
 RM_F = rm -f
 LN_SF = ln -f -s
 
-LIBNAME=libpng16
-PNGMAJ = 16
+LIBNAME=libpng17
+PNGMAJ = 17
 
 prefix=/usr/local
 INCPATH=$(prefix)/include
@@ -47,7 +47,7 @@ CRELEASE = -O2
 LDRELEASE = -s
 WARNMORE=-W -Wall
 CFLAGS = -I$(ZLIBINC) $(WARNMORE) $(CRELEASE)
-LDFLAGS = -L. -L$(ZLIBLIB) -lpng16 -lz -lm $(LDRELEASE)
+LDFLAGS = -L. -L$(ZLIBLIB) -lpng17 -lz -lm $(LDRELEASE)
 
 # File extensions
 O=.o

scripts/makefile.beos

@@ -9,8 +9,8 @@
 # and license in png.h
 
 # Library name:
-LIBNAME=libpng16
-PNGMAJ = 16
+LIBNAME=libpng17
+PNGMAJ = 17
 
 # Shared library names:
 LIBSO=$(LIBNAME).so
@@ -45,7 +45,7 @@ CFLAGS=-I$(ZLIBINC) -W -Wall -O1 -funroll-loops \
 # LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng -lz
 LDFLAGS=-L. -Wl,-soname=$(LIBSOMAJ) -L$(ZLIBLIB) -lz
 
-# where make install puts libpng.a, libpng16.so*, and png.h
+# where make install puts libpng.a, libpng17.so*, and png.h
 prefix=/usr/local
 exec_prefix=$(prefix)
 INCPATH=$(prefix)/include
@@ -91,13 +91,13 @@ libpng.pc:
 	-e s!@exec_prefix@!$(exec_prefix)! \
 	-e s!@libdir@!$(LIBPATH)! \
 	-e s!@includedir@!$(INCPATH)! \
-	-e s!-lpng16!-lpng16\ -lz\ -lm! > libpng.pc
+	-e s!-lpng17!-lpng17\ -lz\ -lm! > libpng.pc
 
 libpng-config:
 	( cat scripts/libpng-config-head.in; \
 	echo prefix=\"$(prefix)\"; \
 	echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
-	echo libs=\"-lpng16 -lz \"; \
+	echo libs=\"-lpng17 -lz \"; \
 	cat scripts/libpng-config-body.in ) > libpng-config
 	chmod +x libpng-config
 
@@ -110,7 +110,7 @@ $(LIBSOMAJ): $(OBJSDLL)
 	$(LIBSOMAJ) $(OBJSDLL) $(LDFLAGS)
 
 pngtest: pngtest.o $(LIBSO)
-	$(CC) -L$(ZLIBLIB) -L. -lz -lpng16 -o pngtest pngtest.o
+	$(CC) -L$(ZLIBLIB) -L. -lz -lpng17 -o pngtest pngtest.o
 
 test: pngtest
 	./pngtest

scripts/makefile.cegcc

@@ -22,16 +22,16 @@
 # make clean
 
 VERMAJ = 1
-VERMIN = 6
+VERMIN = 7
 VERMIC = 0
 VER = $(VERMAJ).$(VERMIN).$(VERMIC)
 NAME = libpng
 PACKAGE = $(NAME)-$(VER)
 
-BIN = libpng16-0.dll
-LIB = libpng16.a libpng16.dll.a libpng.a libpng.dll.a
+BIN = libpng17-0.dll
+LIB = libpng17.a libpng17.dll.a libpng.a libpng.dll.a
 INCLUDE = png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h             pnginfo.h pngdebug.h
-PC = libpng16.pc libpng.pc
+PC = libpng17.pc libpng.pc
 
 MANIFESTVERBIN = "Libpng-$(VER): Binary files"
 MANIFESTVERDEV = "Libpng-$(VER): Developer files"

scripts/makefile.darwin

@@ -9,7 +9,7 @@
 # For conditions of distribution and use, see the disclaimer
 # and license in png.h
 
-# where "make install" puts libpng.a, libpng16.dylib, png.h, pngconf.h,
+# where "make install" puts libpng.a, libpng17.dylib, png.h, pngconf.h,
 # and pnglibconf.h
 prefix=/usr/local
 exec_prefix=$(prefix)
@@ -19,8 +19,8 @@ ZLIBLIB=/usr/lib
 ZLIBINC=/usr/include
 
 # Library name:
-LIBNAME = libpng16
-PNGMAJ = 16
+LIBNAME = libpng17
+PNGMAJ = 17
 
 # Shared library names:
 LIBSO=$(LIBNAME).dylib
@@ -39,7 +39,7 @@ ARCH=-arch ppc -arch i386 -arch x86_64
 
 # CFLAGS=-I$(ZLIBINC) -W -Wall -O3 -funroll-loops
 CFLAGS=-I$(ZLIBINC) -W -Wall -O -funroll-loops $(ARCH)
-LDFLAGS=-L. -L$(ZLIBLIB) -lpng16 -lz $(ARCH)
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng17 -lz $(ARCH)
 
 INCPATH=$(prefix)/include
 LIBPATH=$(exec_prefix)/lib
@@ -87,14 +87,14 @@ libpng.pc:
 	-e s!@exec_prefix@!$(exec_prefix)! \
 	-e s!@libdir@!$(LIBPATH)! \
 	-e s!@includedir@!$(INCPATH)! \
-	-e s!-lpng16!-lpng16\ -lz! > libpng.pc
+	-e s!-lpng17!-lpng17\ -lz! > libpng.pc
 
 libpng-config:
 	( cat scripts/libpng-config-head.in; \
 	echo prefix=\"$(prefix)\"; \
 	echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
 	echo L_opts=\"-L$(LIBPATH)\"; \
-	echo libs=\"-lpng16 -lz\"; \
+	echo libs=\"-lpng17 -lz\"; \
 	cat scripts/libpng-config-body.in ) > libpng-config
 	chmod +x libpng-config
 
@@ -104,7 +104,7 @@ $(LIBSO): $(LIBSOMAJ)
 $(LIBSOMAJ): $(OBJSDLL)
 	$(CC) -dynamiclib \
 	 -install_name $(LIBPATH)/$(LIBSOMAJ) \
-	 -current_version 16 -compatibility_version 16 \
+	 -current_version 17 -compatibility_version 17 \
 	 $(ARCH) -o $(LIBSOMAJ) \
 	 $(OBJSDLL) -L$(ZLIBLIB) -lz