[libpng15] Imported from libpng-1.5.6beta02.tar

macro.

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.5.3beta02 - April 3, 2011
+Libpng 1.5.6beta02 - September 26, 2011
 
 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.
@@ -9,34 +9,41 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.5.3beta02.tar.xz (LZMA-compressed, recommended)
-   1.5.3beta02.tar.gz
-   1.5.3beta02.tar.bz2
+   1.5.6beta02.tar.xz (LZMA-compressed, recommended)
+   1.5.6beta02.tar.gz
+   1.5.6beta02.tar.bz2
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp153b02.7z  (LZMA-compressed, recommended)
-   lp153b02.zip
+   lp156b02.7z  (LZMA-compressed, recommended)
+   lp156b02.zip
 
 Other information:
 
-   1.5.3beta02-README.txt
-   1.5.3beta02-LICENSE.txt
+   1.5.6beta02-README.txt
+   1.5.6beta02-LICENSE.txt
 
-Changes since the last public release (1.5.2):
+Changes since the last public release (1.5.5):
 
-Version 1.5.3beta01 [April 1, 2011]
-  Re-initialize the zlib compressor before compressing non-IDAT chunks.
-  Added API functions to set parameters for zlib compression of non-IDAT
-    chunks.
+Version 1.5.6beta01 [September 22, 2011]
+  Fixed some 64-bit type conversion warnings in pngrtran.c
+  Moved row_info from png_struct to a local variable.
+  The various interlace mask arrays have been made into arrays of
+    bytes and made PNG_CONST and static (previously some arrays were
+    marked PNG_CONST and some weren't).
+  Additional checks have been added to the transform code to validate the
+    pixel depths after the transforms on both read and write.
+  Removed some redundant code from pngwrite.c, in png_desgtroy_write_struct().
+  Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4].
+    This removes the need to allocate temporary strings for chunk names on
+    the stack in the read/write code.  Unknown chunk handling still uses the
+    string form because this is exposed in the API.
 
-Version 1.5.3beta02 [April 3, 2011]
-  Updated scripts/symbols.def with new API functions.
-  Only compile the new zlib re-initializing code when text or iCCP is
-    supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro.
-  Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
-  Optimize the zlib CMF byte in non-IDAT compressed chunks
+Version 1.5.6beta02 [September 26, 2011]
+  Added a note in the manual the png_read_update_info() must be called only
+    once with a particular info_ptr.
+  Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
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CHANGES

@@ -1,5 +1,4 @@
 #if 0
-libpng_changes(){ /*
 CHANGES - changes for libpng
 
 Version 0.2
@@ -15,7 +14,7 @@ Version 0.3
   fixed some bugs in writer
   interfaced with zlib 0.5
   added K&R support
-  added check for 64 KB blocks for 16 bit machines
+  added check for 64 KB blocks for 16-bit machines
 
 Version 0.4
   cleaned up code and commented code
@@ -74,7 +73,7 @@ Version 0.82 [September, 1995]
 Version 0.85 [December, 1995]
   added more medium model code (almost everything's a far)
   added i/o, error, and memory callback functions
-  fixed some bugs (16 bit, 4 bit interlaced, etc.)
+  fixed some bugs (16-bit, 4-bit interlaced, etc.)
   added first run progressive reader (barely tested)
 
 Version 0.86 [January, 1996]
@@ -180,7 +179,7 @@ Version 0.96 [May, 1997]
   Fixed serious bug with < 8bpp images introduced in 0.95
   Fixed 256-color transparency bug (Greg Roelofs)
   Fixed up documentation (Greg Roelofs, Laszlo Nyul)
-  Fixed "error" in pngconf.h for Linux setjmp() behaviour
+  Fixed "error" in pngconf.h for Linux setjmp() behavior
   Fixed DOS medium model support (Tim Wegner)
   Fixed png_check_keyword() for case with error in static string text
   Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
@@ -204,8 +203,8 @@ Version 0.97 [January, 1998]
   Added more conditions for png_do_background, to avoid changing
     black pixels to background when a background is supplied and
     no pixels are transparent
-  Repaired PNG_NO_STDIO behaviour
-  Tested NODIV support and made it default behaviour (Greg Roelofs)
+  Repaired PNG_NO_STDIO behavior
+  Tested NODIV support and made it default behavior (Greg Roelofs)
   Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
   Regularized version numbering scheme and bumped shared-library major
      version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)
@@ -1778,7 +1777,7 @@ Version 1.2.13beta1 [October 2, 2006]
   Removed AC_FUNC_MALLOC from configure.ac
   Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
   Change "logical" to "bitwise" throughout documentation.
-  Detect and fix attempt to write wrong iCCP profile length.
+  Detect and fix attempt to write wrong iCCP profile length (CVE-2006-7244)
 
 Version 1.0.21, 1.2.13 [November 14, 2006]
   Fix potential buffer overflow in sPLT chunk handler.
@@ -2361,7 +2360,7 @@ Version 1.4.0beta72 [August 1, 2009]
 
 Version 1.4.0beta73 [August 1, 2009]
   Reject attempt to write iCCP chunk with negative embedded profile length
-    (JD Chen)
+    (JD Chen) (CVE-2009-5063).
 
 Version 1.4.0beta74 [August 8, 2009]
   Changed png_ptr and info_ptr member "trans" to "trans_alpha".
@@ -2935,7 +2934,7 @@ Version 1.5.0beta36 [July 29, 2010]
     PNG_INTERLACE transform and to get the number of rows in the current
     pass.
   A new test program, pngvalid.c, validates the gamma code.
-  Errors in the 16 bit gamma correction (overflows) have been corrected.
+  Errors in the 16-bit gamma correction (overflows) have been corrected.
   cHRM chunk testing is done consistently (previously the floating point
     API bypassed it, because the test really didn't work on FP, now the test
     is performed on the actual values to be stored in the PNG file so it
@@ -3149,8 +3148,8 @@ version 1.5.1beta01 [January 8, 2011]
     in version 1.5.0beta36 but is not noted in the CHANGES.  Similarly,
     it was changed from png_charpp to png_const_bytepp in png_set_iCCP().
   Ensure that png_rgb_to_gray ignores palette mapped images, if libpng
-    internally happens to call it with one.
-  Fixed a failure to handle palette mapped images correctly.
+    internally happens to call it with one, and fixed a failure to handle
+    palette mapped images correctly.  This fixes CVE-2690.
 
 Version 1.5.1beta02 [January 14, 2011]
   Fixed a bug in handling of interlaced images (bero at arklinux.org).
@@ -3208,9 +3207,9 @@ Version 1.5.1beta09 [January 24, 2011]
     pngvalid contains tests of transforms, which tests are currently disabled
     because they are incompletely tested.  gray_to_rgb was failing to expand
     the bit depth for smaller bit depth images; this seems to be a long
-    standing error and resulted, apparently, in invalid output.  The
-    documentation did not accurately describe what libpng really does when
-    converting RGB to gray.
+    standing error and resulted, apparently, in invalid output
+    (CVE-2011-0408, CERT VU#643140).  The documentation did not accurately
+    describe what libpng really does when converting RGB to gray.
 
 Version 1.5.1beta10 [January 27, 2010]
   Fixed incorrect examples of callback prototypes in the manual, that were
@@ -3227,7 +3226,7 @@ Version 1.5.1beta10 [January 27, 2010]
 Version 1.5.1beta11 [January 28, 2011]
   Changed PNG_UNUSED from "param=param;" to "{if(param){}}".
   Corrected local variable type in new API png_process_data_skip()
-    The type was self-evidently incorrect but only causes problems on 64 bit
+    The type was self-evidently incorrect but only causes problems on 64-bit
     architectures.
   Added transform tests to pngvalid and simplified the arguments.
 
@@ -3289,8 +3288,8 @@ Version 1.5.2 [March 31, 2011]
 
 Version 1.5.3beta01 [April 1, 2011]
   Re-initialize the zlib compressor before compressing non-IDAT chunks.
-  Added API functions to set parameters for zlib compression of non-IDAT
-    chunks.
+  Added API functions (png_set_text_compression_level() and four others) to
+    set parameters for zlib compression of non-IDAT chunks.
 
 Version 1.5.3beta02 [April 3, 2011]
   Updated scripts/symbols.def with new API functions.
@@ -3299,6 +3298,314 @@ Version 1.5.3beta02 [April 3, 2011]
   Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
   Optimize the zlib CMF byte in non-IDAT compressed chunks
 
+Version 1.5.3beta03 [April 16, 2011]
+  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
+    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
+    than __STDC__ (John Bowler).
+  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
+    the compiler that a user supplied callback (the error handler) does not
+    return, yet there is no guarantee in practice that the application code
+    will correctly implement the error handler because the compiler only
+    issues a warning if there is a mistake (John Bowler).
+  Removed the no-longer-used PNG_DEPSTRUCT macro.
+  Updated the zlib version to 1.2.5 in the VStudio project.
+  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
+    pngwutil.c (John Bowler).
+  Fixed bug with stripping the filler or alpha channel when writing, that
+    was introduced in libpng-1.5.2beta01 (bug report by Andrew Church).
+
+Version 1.5.3beta04 [April 27, 2011]
+  Updated pngtest.png with the new zlib CMF optimization.
+  Cleaned up conditional compilation code and of background/gamma handling
+    Internal changes only except a new option to avoid compiling the
+    png_build_grayscale_palette API (which is not used at all internally.)
+    The main change is to move the transform tests (READ_TRANSFORMS,
+    WRITE_TRANSFORMS) up one level to the caller of the APIs.  This avoids
+    calls to spurious functions if all transforms are disabled and slightly
+    simplifies those functions.  Pngvalid modified to handle this.
+    A minor change is to stop the strip_16 and expand_16 interfaces from
+    disabling each other; this allows the future alpha premultiplication
+    code to use 16-bit intermediate values while still producing 8-bit output.
+    png_do_background and png_do_gamma have been simplified to take a single
+    pointer to the png_struct rather than pointers to every item required
+    from the png_struct. This makes no practical difference to the internal
+    code.
+  A serious bug in the pngvalid internal routine 'standard_display_init' has
+    been fixed - this failed to initialize the red channel and accidentally
+    initialized the alpha channel twice.
+  Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
+    avoid a possible clash with the png_jmpbuf macro on some platforms.
+
+Version 1.5.3beta05 [May 6, 2011]
+  Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the
+    correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and
+    pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs.
+  Removed png_snprintf and added formatted warning messages.  This change adds
+    internal APIs to allow png_warning messages to have parameters without
+    requiring the host OS to implement snprintf.  As a side effect the
+    dependency of the tIME-supporting RFC1132 code on stdio is removed and
+    PNG_NO_WARNINGS does actually work now.
+  Pass "" instead of '\0' to png_default_error() in png_err().  This mistake
+    was introduced in libpng-1.2.20beta01.  This fixes CVE-2011-2691.
+  Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
+    optimization configureable.
+  IDAT compression failed if preceded by a compressed text chunk (bug
+    introduced in libpng-1.5.3beta01-02).  This was because the attempt to
+    reset the zlib stream in png_write_IDAT happened after the first IDAT
+    chunk had been deflated - much too late.  In this change internal
+    functions were added to claim/release the z_stream and, hopefully, make
+    the code more robust.  Also deflateEnd checking is added - previously
+    libpng would ignore an error at the end of the stream.
+
+Version 1.5.3beta06 [May 8, 2011]
+  Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
+  Implemented premultiplied alpha support: png_set_alpha_mode API
+
+Version 1.5.3beta07 [May 11, 2011]
+  Added expand_16 support to the high level interface.
+  Added named value and 'flag' gamma support to png_set_gamma.  Made a minor
+    change from the previous (unreleased) ABI/API to hide the exact value used
+    for Macs - it's not a good idea to embed this in the ABI!
+  Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
+    from pngpriv.h to png.h because they must be visible to applications
+    that call png_set_unknown_chunks().
+  Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
+    before IDAT.
+
+Version 1.5.3beta08 [May 16, 2011]
+  Improved "pngvalid --speed" to exclude more of pngvalid from the time.
+  Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
+  The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
+    parameters are supplied by the caller), while in the absence of cHRM
+    sRGB/Rec 709 values are still used.  This introduced a divide-by-zero
+    bug in png_handle_cHRM().
+  The bKGD chunk no longer overwrites the background value set by
+    png_set_background(), allowing the latter to be used before the file
+    header is read. It never performed any useful function to override
+    the default anyway.
+  Added memory overwrite and palette image checks to pngvalid.c
+    Previously palette image code was poorly checked. Since the transformation
+    code has a special palette path in most cases this was a severe weakness.
+  Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
+    expanding an indexed image, always expand to RGBA if transparency is
+    present.
+
+Version 1.5.3beta09 [May 17, 2011]
+  Reversed earlier 1.5.3 change of transformation order; move png_expand_16
+    back where it was.  The change doesn't work because it requires 16-bit
+    gamma tables when the code only generates 8-bit ones.  This fails
+    silently; the libpng code just doesn't do any gamma correction.  Moving
+    the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
+    these are clearly better than none!
+
+Version 1.5.3beta10 [May 20, 2011]
+
+  png_set_background() and png_expand_16() did not work together correctly.
+    This problem is present in 1.5.2; if png_set_background is called with
+    need_expand false and the matching 16 bit color libpng erroneously just
+    treats it as an 8-bit color because of where png_do_expand_16 is in the
+    transform list.  This simple fix reduces the supplied colour to 8-bits,
+    so it gets smashed, but this is better than the current behavior.
+  Added tests for expand16, more fixes for palette image tests to pngvalid.
+    Corrects the code for palette image tests and disables attempts to
+    validate palette colors.
+
+Version 1.5.3rc01 [June 3, 2011]
+  No changes.
+
+Version 1.5.3rc02 [June 8, 2011]
+  Fixed uninitialized memory read in png_format_buffer() (Bug report by
+    Frank Busse, CVE-2011-2501, related to CVE-2004-0421).
+
+Version 1.5.3beta11 [June 11, 2011]
+  Fixed png_handle_sCAL which is broken in 1.5. This fixes CVE 2011-2692.
+  Added sCAL to pngtest.png
+  Revised documentation about png_set_user_limits() to say that it also affects
+    png writing.
+  Revised handling of png_set_user_limits() so that it can increase the
+    limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
+    reduce it.
+  Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
+    wrong (high by one) 25% of the time. Dividing by 257 with rounding is
+    wrong in 128 out of 65536 cases. Getting the right answer all the time
+    without division is easy.
+  Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
+  Added projects/owatcom, an IDE project for OpenWatcom to replace
+    scripts/makefile.watcom.  This project works with OpenWatcom 1.9. The
+    IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
+    The project is configurable, unlike the Visual Studio project, so long
+    as the developer has an awk.
+  Changed png_set_gAMA to limit the gamma value range so that the inverse
+    of the stored value cannot overflow the fixed point representation,
+    and changed other things OpenWatcom warns about.
+  Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
+    pngvalid to build when ALPHA_MODE is not supported, which is required if
+    it is to build on libpng 1.4.
+  Removed string/memory macros that are no longer used and are not
+    necessarily fully supportable, particularly png_strncpy and png_snprintf.
+  Added log option to pngvalid.c and attempted to improve gamma messages.
+  
+Version 1.5.3 [omitted]
+  People found the presence of a beta release following an rc release
+    to be confusing; therefore we bump the version to libpng-1.5.4beta01
+    and there will be no libpng-1.5.3 release.
+
+Version 1.5.4beta01 [June 14, 2011]
+  Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+    to get the same (inaccurate) output as libpng-1.5.2 and earlier.
+  Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
+    outside of an unknown-chunk block in png.h because they are also
+    needed for other uses.
+
+Version 1.5.4beta02 [June 14, 2011]
+  Fixed and clarified LEGACY 16-to-8 scaling code.
+  Added png_set_chop_16() API, to match inaccurate results from previous
+    libpng versions.
+  Removed the ACCURATE and LEGACY options (they are no longer useable)
+  Use the old scaling method for background if png_set_chop_16() was
+    called.
+  Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED
+
+Version 1.5.4beta03 [June 15, 2011]
+  Fixed a problem in png_do_expand_palette() exposed by optimization in
+    1.5.3beta06
+  Also removed a spurious and confusing "trans" member ("trans") from png_info.
+  The palette expand optimization prevented expansion to an intermediate RGBA
+    form if tRNS was present but alpha was marked to be stripped; this exposed
+    a check for tRNS in png_do_expand_palette() which is inconsistent with the
+    code elsewhere in libpng.
+  Correction to the expand_16 code; removed extra instance of
+    png_set_scale_16_to_8 from pngpriv.h
+
+Version 1.5.4beta04 [June 16, 2011]
+  Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
+  Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
+  Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again.  If this is
+    not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
+  Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8
+
+Version 1.5.4beta05 [June 16, 2011]
+  Renamed png_set_strip_16() to png_set_scale_16() and renamed
+    png_set_chop_16() to png_set_strip(16) in an attempt to minimize the
+    behavior changes between libpng14 and libpng15.
+
+Version 1.5.4beta06 [June 18, 2011]
+  Fixed new bug that was causing both strip_16 and scale_16 to be applied.
+
+Version 1.5.4beta07 [June 19, 2011]
+  Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
+    The ACCURATE scale macro is no longer defined in 1.5 - call the
+    png_scale_16_to_8 API.  Made sure that PNG_READ_16_TO_8 is still defined
+    if the png_strip_16_to_8 API is present.  png_check_fp_number now
+    maintains some state so that positive, negative and zero values are
+    identified.  sCAL uses these to be strictly spec conformant.
+
+Version 1.5.4beta08 [June 23, 2011]
+  Fixed pngvalid if ACCURATE_SCALE is defined.
+  Updated scripts/pnglibconf.h.prebuilt.
+
+Version 1.5.4rc01 [June 30, 2011]
+  Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.
+
+Version 1.5.4 [July 7, 2011]
+  No changes.
+
+Version 1.5.5beta01 [July 13, 2011]
+  Fixed some typos and made other minor changes in the manual.
+  Updated contrib/pngminus/makefile.std (Samuli Souminen)
+
+Version 1.5.5beta02 [July 14, 2011]
+  Revised Makefile.am and Makefile.in to look in the right directory for
+    pnglibconf.h.prebuilt
+
+Version 1.5.5beta03 [July 27, 2011]
+  Enabled compilation with g++ compiler.  This compiler does not recognize
+    the file extension, so it always compiles with C++ rules.  Made minor
+    changes to pngrutil.c to cast results where C++ expects it but C does not.
+  Minor editing of libpng.3 and libpng-manual.txt.
+
+Version 1.5.5beta04 [July 29, 2011]
+  Revised CMakeLists.txt (Clifford Yapp)
+  Updated commentary about the png_rgb_to_gray() default coefficients
+    in the manual and in pngrtran.c
+
+Version 1.5.5beta05 [August 17, 2011]
+  Prevent unexpected API exports from non-libpng DLLs on Windows.  The "_DLL"
+    is removed from the test of whether a DLL is being built (this erroneously
+    caused the libpng APIs to be marked as DLL exports in static builds under
+    Microsoft Visual Studio).  Almost all of the libpng building configuration
+    is moved from pngconf.h to pngpriv.h, but PNG_DLL_EXPORT remains in
+    pngconf.h, though, so that it is colocated with the import definition (it
+    is no longer used anywhere in the installed headers).  The VStudio project
+    definitions have been cleaned up: "_USRDLL" has been removed from the
+    static library builds (this was incorrect), and PNG_USE_DLL has been added
+    to pngvalid to test the functionality (pngtest does not supply it,
+    deliberately).  The spurious "_EXPORTS" has been removed from the
+    libpng build (all these errors were a result of copy/paste between project
+    configurations.)
+  Added new types and internal functions for CIE RGB end point handling to
+    pngpriv.h (functions yet to be implemented).
+
+Version 1.5.5beta06 [August 26, 2011]
+  Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set in CMakeLists.txt
+    (Clifford Yap)
+  Fixes to rgb_to_gray and cHRM XYZ APIs (John Bowler):
+    The rgb_to_gray code had errors when combined with gamma correction.
+    Some pixels were treated as true grey when they weren't and such pixels
+    and true grey ones were not gamma corrected (the original value of the
+    red component was used instead).  APIs to get and set cHRM using color
+    space end points have been added and the rgb_to_gray code that defaults
+    based on cHRM, and the divide-by-zero bug in png_handle_cHRM (CERT
+    VU#477046, CVE-2011-3328, introduced in 1.5.4) have been corrected.
+  A considerable number of tests has been added to pngvalid for the
+    rgb_to_gray transform.
+  Arithmetic errors in rgb_to_gray whereby the calculated gray value was
+    truncated to the bit depth rather than rounded have been fixed except in
+    the 8-bit non-gamma-corrected case (where consistency seems more important
+    than correctness.)  The code still has considerable inaccuracies in the
+    8-bit case because 8-bit linear arithmetic is used.
+
+Version 1.5.5beta07 [September 7, 2011]
+  Added "$(ARCH)" option to makefile.darwin
+  Added SunOS support to configure.ac and Makefile.am
+  Changed png_chunk_benign_error() to png_warning() in png.c, in
+    png_XYZ_from_xy_checked().
+
+Version 1.5.5beta08 [September 10, 2011]
+  Fixed 64-bit compilation errors (gcc). The errors fixed relate
+    to conditions where types that are 32 bits in the GCC 32-bit
+    world (uLong and png_size_t) become 64 bits in the 64-bit
+    world.  This produces potential truncation errors which the
+    compiler correctly flags.
+  Relocated new HAVE_SOLARIS_LD definition in configure.ac
+  Constant changes for 64-bit compatibility (removal of L suffixes). The
+    16-bit cases still use "L" as we don't have a 16-bit test system.
+
+Version 1.5.5rc01 [September 15, 2011]
+  Removed "L" suffixes in pngpriv.h
+
+Version 1.5.5 [September 22, 2011]
+  No changes.
+
+Version 1.5.6beta01 [September 22, 2011]
+  Fixed some 64-bit type conversion warnings in pngrtran.c
+  Moved row_info from png_struct to a local variable.
+  The various interlace mask arrays have been made into arrays of
+    bytes and made PNG_CONST and static (previously some arrays were
+    marked PNG_CONST and some weren't).
+  Additional checks have been added to the transform code to validate the
+    pixel depths after the transforms on both read and write.
+  Removed some redundant code from pngwrite.c, in png_destroy_write_struct().
+  Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4].
+    This removes the need to allocate temporary strings for chunk names on
+    the stack in the read/write code.  Unknown chunk handling still uses the
+    string form because this is exposed in the API.
+
+Version 1.5.6beta02 [September 26, 2011]
+  Added a note in the manual the png_read_update_info() must be called only
+    once with a particular info_ptr.
+  Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro.
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
@@ -3306,5 +3613,4 @@ to subscribe)
 or to glennrp at users.sourceforge.net
 
 Glenn R-P
-*/ }
 #endif

CMakeLists.txt

@@ -1,3 +1,11 @@
+# CMakeLists.txt
+
+# Copyright (C) 2007-2011 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
+
 cmake_minimum_required(VERSION 2.4.4)
 set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS true)
 
@@ -25,15 +33,9 @@ endif()
 project(libpng C)
 enable_testing()
 
-# Copyright (C) 2007-2011 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
-
 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 5)
-set(PNGLIB_RELEASE 3)
+set(PNGLIB_RELEASE 6)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
@@ -147,10 +149,6 @@ set(pngtest_sources
 
 add_definitions(-DPNG_CONFIGURE_LIBPNG)
 
-if(_AIX)
-  add_definitions(-D_ALL_SOURCE)
-endif(_AIX)
-
 if(MSVC)
   add_definitions(-DPNG_NO_MODULEDEF -D_CRT_SECURE_NO_DEPRECATE)
 endif(MSVC)
@@ -160,7 +158,6 @@ if(PNG_SHARED OR  NOT MSVC)
   add_definitions(-DZLIB_DLL)
 endif()
 
-
 if(PNG_CONSOLE_IO_SUPPORTED)
   add_definitions(-DPNG_CONSOLE_IO_SUPPORTED)
 endif()
@@ -205,7 +202,6 @@ if(PNG_STATIC)
   target_link_libraries(${PNG_LIB_NAME_STATIC} ${ZLIB_LIBRARY} ${M_LIBRARY})
 endif()
 
-
 if(PNG_SHARED AND WIN32)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL)
 endif()
@@ -217,24 +213,32 @@ if(PNG_TESTS AND PNG_SHARED)
   add_test(pngtest ./pngtest ${CMAKE_CURRENT_SOURCE_DIR}/pngtest.png)
 endif()
 
-#
+# Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set
+IF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+  IF(WIN32)
+    SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "bin")
+  ELSE(WIN32)
+    SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib")
+  ENDIF(WIN32)
+ENDIF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+
 # Set a variable with CMake code which:
 # Creates a symlink from src to dest (if possible) or alternatively
 # copies if different.
-macro(_png_generate_symlink_code CODE SRC DEST)
+macro(CREATE_SYMLINK SRC_FILE DEST_FILE)
+  FILE(REMOVE ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
   if(WIN32 AND NOT CYGWIN)
-    set(_png_gsc_message "Copying ${SRC} to ${DEST} if needed")
-    set(_png_gsc_operation "copy_if_different")
-  else()
-    set(_png_gsc_message "Symlinking ${SRC} to ${DEST}")
-    set(_png_gsc_operation "create_symlink")
-  endif()
-
-  set(${CODE} "
-    message(STATUS \"${_png_gsc_message}\")
-    execute_process(COMMAND \${CMAKE_COMMAND} -E ${_png_gsc_operation}
-      \"${SRC}\" \"${DEST}\")
-    ")
+    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} ${PNG_LIB_NAME_STATIC}
+        )
+    ADD_CUSTOM_TARGET(${DEST_FILE}_COPY ALL DEPENDS ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
+  else(WIN32 AND NOT CYGWIN)
+    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})
+  endif(WIN32 AND NOT CYGWIN)
 endmacro()
 
 # CREATE PKGCONFIG FILES
@@ -249,22 +253,16 @@ set(includedir  ${CMAKE_INSTALL_PREFIX}/include)
 set(LIBS        "-lz -lm")
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
   ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY)
-_png_generate_symlink_code(PNG_PC_INSTALL_CODE
-  ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc
-  ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc)
-install(CODE ${PNG_PC_INSTALL_CODE})
+CREATE_SYMLINK(${PNGLIB_NAME}.pc libpng.pc)
 
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in
   ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY)
-_png_generate_symlink_code(PNG_CONFIG_INSTALL_CODE
-  ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
-  ${CMAKE_CURRENT_BINARY_DIR}/libpng-config)
-install(CODE ${PNG_CONFIG_INSTALL_CODE})
+CREATE_SYMLINK(${PNGLIB_NAME}-config libpng-config)
 
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 15.${PNGLIB_RELEASE}.1.5.3beta02
+#   VERSION 15.${PNGLIB_RELEASE}.1.5.6beta02
     VERSION 15.${PNGLIB_RELEASE}.0
     SOVERSION 15
     CLEAN_DIRECT_OUTPUT 1)
@@ -300,61 +298,35 @@ if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
 
     # Create a symlink for libpng.dll.a => libpng15.dll.a on Cygwin
     if(CYGWIN)
-      _png_generate_symlink_code(PNG_SHARED_IMPLIB_INSTALL_CODE
-        ${PNGLIB_NAME}${CMAKE_IMPORT_LIBRARY_SUFFIX}
-        libpng${CMAKE_IMPORT_LIBRARY_SUFFIX})
-      install(CODE ${PNG_SHARED_IMPLIB_INSTALL_CODE})
-      install(FILES
-        ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}
-        DESTINATION ${CMAKE_INSTALL_LIBDIR})
-    endif()
+       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})
+       install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(CYGWIN)
 
     if(NOT WIN32)
-      IF(CMAKE_LIBRARY_OUTPUT_DIRECTORY)
-        _png_generate_symlink_code(PNG_SHARED_INSTALL_CODE
- ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${PNGLIB_NAME}${CMAKE_SHARED_LIBRARY_SUFFIX}
- ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
-                install(CODE ${PNG_SHARED_INSTALL_CODE})
-                install(FILES
- ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
-                DESTINATION ${CMAKE_INSTALL_LIBDIR})
-      ELSE(CMAKE_LIBRARY_OUTPUT_DIRECTORY)
-        _png_generate_symlink_code(PNG_SHARED_INSTALL_CODE
-           ${PNGLIB_NAME}${CMAKE_SHARED_LIBRARY_SUFFIX}
-           libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
-        install(CODE ${PNG_SHARED_INSTALL_CODE})
-        install(FILES
-           ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
-                DESTINATION ${CMAKE_INSTALL_LIBDIR})
-      ENDIF(CMAKE_LIBRARY_OUTPUT_DIRECTORY)
-    endif()
-  endif()
+      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})
+      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})
+        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
     if(NOT WIN32 OR CYGWIN)
-      IF(CMAKE_ARCHIVE_OUTPUT_DIRECTORY)
-         _png_generate_symlink_code(PNG_STATIC_INSTALL_CODE
-${CMAKE_ARCHIVE_OUTPUT_DIRECTORY}/${PNGLIB_NAME}${CMAKE_STATIC_LIBRARY_SUFFIX}
-        ${CMAKE_ARCHIVE_OUTPUT_DIRECTORY}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
-        install(CODE ${PNG_STATIC_INSTALL_CODE})
-        install(FILES
-          ${CMAKE_ARCHIVE_OUTPUT_DIRECTORY}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
-             DESTINATION ${CMAKE_INSTALL_LIBDIR})
-      ELSE(CMAKE_ARCHIVE_OUTPUT_DIRECTORY)
-        _png_generate_symlink_code(PNG_STATIC_INSTALL_CODE
-           ${PNGLIB_NAME}${CMAKE_STATIC_LIBRARY_SUFFIX}
-           libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
-        install(CODE ${PNG_STATIC_INSTALL_CODE})
-        install(FILES
-          ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
-                     DESTINATION ${CMAKE_INSTALL_LIBDIR})
-      ENDIF(CMAKE_ARCHIVE_OUTPUT_DIRECTORY)
-    endif()
-  endif()
+      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})
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32 OR CYGWIN)
+ endif()
 endif()
 
 if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
@@ -392,11 +364,9 @@ endif()
 
 # what's with libpng-$VER%.txt and all the extra files?
 
-
 # UNINSTALL
 # do we need this?
 
-
 # DIST
 # do we need this?
 

LICENSE

@@ -10,7 +10,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.5.3beta02, April 3, 2011, are
+libpng versions 1.2.6, August 15, 2004, through 1.5.6beta02, September 26, 2011, are
 Copyright (c) 2004, 2006-2011 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
-April 3, 2011
+September 26, 2011

Makefile.am

@@ -18,13 +18,13 @@ pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 pngvalid_SOURCES = pngvalid.c
 pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 TESTS = test-pngtest.sh test-pngvalid-simple.sh test-pngvalid-full.sh
-TESTS_ENVIRONMENT= srcdir=$(srcdir) 
+TESTS_ENVIRONMENT= srcdir=$(srcdir)
 
 # man pages
 dist_man_MANS= libpng.3 libpngpf.3 png.5
 
 # generate the -config scripts if required
-binconfigs= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config 
+binconfigs= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
 EXTRA_SCRIPTS= libpng-config libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
 bin_SCRIPTS= @binconfigs@
 
@@ -44,11 +44,16 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined -export-dynamic \
 	-version-number @PNGLIB_MAJOR@@PNGLIB_MINOR@:@PNGLIB_RELEASE@:0
 
 if HAVE_LD_VERSION_SCRIPT
-  # Versioned symbols and restricted exports
+#   Versioned symbols and restricted exports
+if HAVE_SOLARIS_LD
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS += -Wl,-M Wl,libpng.vers
+else
   libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS += -Wl,--version-script=libpng.vers
+endif
+
   libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.vers
 else
-  # Only restricted exports when possible
+#   Only restricted exports when possible
   libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS += -export-symbols libpng.sym
   libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.sym
 endif
@@ -97,7 +102,7 @@ $(PNGLIB_BASENAME)-config: libpng-config
 	cp libpng-config $@
 
 scripts/sym.out scripts/vers.out: png.h pngconf.h pnglibconf.h
-scripts/symbols.out: png.h pngconf.h scripts/pnglibconf.h.prebuilt
+scripts/symbols.out: png.h pngconf.h $(srcdir)/scripts/pnglibconf.h.prebuilt
 
 libpng.sym: scripts/sym.out
 	rm -f $@
@@ -108,7 +113,8 @@ libpng.vers: scripts/vers.out
 pnglibconf.h: pnglibconf.out
 	rm -f $@
 	cp $? $@
-scripts/pnglibconf.h.prebuilt:
+$(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
 	@exit 1
@@ -119,8 +125,8 @@ scripts/pnglibconf.h.prebuilt:
 pngvalid.o pngtest.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 stops the read macros interfering
-# with the symbol file format.
+# be built with PNG_USE_READ_MACROS; this prevents the read macros from
+# interfering with the symbol file format.
 SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0'\
 		-DPNGLIB_VERSION='@PNGLIB_VERSION@'\
 		-DSYMBOL_PREFIX='$(SYMBOL_PREFIX)'\
@@ -159,10 +165,10 @@ scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.ou
 # be empty - no non-standard defines
 scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk
 	rm -f $@ dfn?.out
-	test -z "$(CPPFLAGS)" 
+	test -z "$(CPPFLAGS)"
 	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
 	$(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out\
-	    logunsupported=3 - ${srcdir}/scripts/pnglibconf.dfa 1>&2
+	    logunsupported=1 - ${srcdir}/scripts/pnglibconf.dfa 1>&2
 	$(AWK) -f ${srcdir}/scripts/options.awk out=dfn2.out dfn1.out 1>&2
 	rm dfn1.out
 	mv dfn2.out $@

Makefile.in

@@ -41,8 +41,12 @@ POST_UNINSTALL = :
 build_triplet = @build@
 host_triplet = @host@
 check_PROGRAMS = pngtest$(EXEEXT) pngvalid$(EXEEXT)
-@HAVE_LD_VERSION_SCRIPT_TRUE@am__append_1 = -Wl,--version-script=libpng.vers
-@HAVE_LD_VERSION_SCRIPT_FALSE@am__append_2 = -export-symbols libpng.sym
+
+#   Versioned symbols and restricted exports
+@HAVE_LD_VERSION_SCRIPT_TRUE@@HAVE_SOLARIS_LD_TRUE@am__append_1 = -Wl,-M Wl,libpng.vers
+@HAVE_LD_VERSION_SCRIPT_TRUE@@HAVE_SOLARIS_LD_FALSE@am__append_2 = -Wl,--version-script=libpng.vers
+#   Only restricted exports when possible
+@HAVE_LD_VERSION_SCRIPT_FALSE@am__append_3 = -export-symbols libpng.sym
 subdir = .
 DIST_COMMON = README $(am__configure_deps) $(dist_man_MANS) \
 	$(pkginclude_HEADERS) $(srcdir)/Makefile.am \
@@ -252,7 +256,7 @@ am__tar = @am__tar@
 am__untar = @am__untar@
 
 # generate the -config scripts if required
-binconfigs = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config 
+binconfigs = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
 bindir = @bindir@
 build = @build@
 build_alias = @build_alias@
@@ -310,7 +314,7 @@ pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 pngvalid_SOURCES = pngvalid.c
 pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 TESTS = test-pngtest.sh test-pngvalid-simple.sh test-pngvalid-full.sh
-TESTS_ENVIRONMENT = srcdir=$(srcdir) 
+TESTS_ENVIRONMENT = srcdir=$(srcdir)
 
 # man pages
 dist_man_MANS = libpng.3 libpngpf.3 png.5
@@ -330,7 +334,7 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_CPPFLAGS = @LIBPNG_DEFINES@
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined \
 	-export-dynamic -version-number \
 	@PNGLIB_MAJOR@@PNGLIB_MINOR@:@PNGLIB_RELEASE@:0 \
-	$(am__append_1) $(am__append_2)
+	$(am__append_1) $(am__append_2) $(am__append_3)
 @HAVE_LD_VERSION_SCRIPT_FALSE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.sym
 @HAVE_LD_VERSION_SCRIPT_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.vers
 pkginclude_HEADERS = png.h pngconf.h
@@ -357,8 +361,8 @@ config.sub configure depcomp install-sh ltmain.sh missing
 SUFFIXES = .chk .dfn .out
 
 # We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually
-# be built with PNG_USE_READ_MACROS; this stops the read macros interfering
-# with the symbol file format.
+# be built with PNG_USE_READ_MACROS; this prevents the read macros from
+# interfering with the symbol file format.
 SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0'\
 		-DPNGLIB_VERSION='@PNGLIB_VERSION@'\
 		-DSYMBOL_PREFIX='$(SYMBOL_PREFIX)'\
@@ -1255,9 +1259,6 @@ uninstall-man: uninstall-man3 uninstall-man5
 	uninstall-pkgconfigDATA uninstall-pkgincludeHEADERS
 
 
-@HAVE_LD_VERSION_SCRIPT_TRUE@  # Versioned symbols and restricted exports
-@HAVE_LD_VERSION_SCRIPT_FALSE@  # Only restricted exports when possible
-
 $(PNGLIB_BASENAME).pc: libpng.pc
 	cp libpng.pc $@
 
@@ -1265,7 +1266,7 @@ $(PNGLIB_BASENAME)-config: libpng-config
 	cp libpng-config $@
 
 scripts/sym.out scripts/vers.out: png.h pngconf.h pnglibconf.h
-scripts/symbols.out: png.h pngconf.h scripts/pnglibconf.h.prebuilt
+scripts/symbols.out: png.h pngconf.h $(srcdir)/scripts/pnglibconf.h.prebuilt
 
 libpng.sym: scripts/sym.out
 	rm -f $@
@@ -1276,7 +1277,8 @@ libpng.vers: scripts/vers.out
 pnglibconf.h: pnglibconf.out
 	rm -f $@
 	cp $? $@
-scripts/pnglibconf.h.prebuilt:
+$(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
 	@exit 1
@@ -1319,7 +1321,7 @@ scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.ou
 # be empty - no non-standard defines
 scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk
 	rm -f $@ dfn?.out
-	test -z "$(CPPFLAGS)" 
+	test -z "$(CPPFLAGS)"
 	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
 	$(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out\
 	    logunsupported=1 - ${srcdir}/scripts/pnglibconf.dfa 1>&2

README

@@ -1,4 +1,4 @@
-README for libpng version 1.5.3beta02 - April 3, 2011 (shared library 15.0)
+README for libpng version 1.5.6beta02 - September 26, 2011 (shared library 15.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
@@ -114,19 +114,16 @@ given in previous versions of this document.  He and Andreas will
 read mail addressed to the png-implement list, however.
 
 Please do not send general questions about PNG.  Send them to
-the (png-list at ccrc.wustl.edu, subscription required, write to
-majordomo at ccrc.wustl.edu with "subscribe png-list" in your message).
-On the other hand,
-please do not send libpng questions to that address, send them to me
-or to the png-implement list.  I'll
-get them in the end anyway.  If you have a question about something
+png-mng-misc at lists.sf.net (subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
+subscribe).  If you have a question about something
 in the PNG specification that is related to using libpng, send it
 to me.  Send me any questions that start with "I was using libpng,
 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 nine years now, and it is official and
+been discussing PNG for sixteen 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.

configure

@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.68 for libpng 1.5.3beta02.
+# Generated by GNU Autoconf 2.68 for libpng 1.5.6beta02.
 #
 # Report bugs to <png-mng-implement@lists.sourceforge.net>.
 #
@@ -570,8 +570,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='libpng'
 PACKAGE_TARNAME='libpng'
-PACKAGE_VERSION='1.5.3beta02'
-PACKAGE_STRING='libpng 1.5.3beta02'
+PACKAGE_VERSION='1.5.6beta02'
+PACKAGE_STRING='libpng 1.5.6beta02'
 PACKAGE_BUGREPORT='png-mng-implement@lists.sourceforge.net'
 PACKAGE_URL=''
 
@@ -624,6 +624,8 @@ PNGLIB_VERSION
 SYMBOL_PREFIX
 HAVE_LD_VERSION_SCRIPT_FALSE
 HAVE_LD_VERSION_SCRIPT_TRUE
+HAVE_SOLARIS_LD_FALSE
+HAVE_SOLARIS_LD_TRUE
 LIBPNG_DEFINES
 LIBOBJS
 POW_LIB
@@ -763,8 +765,7 @@ CFLAGS
 LDFLAGS
 LIBS
 CPPFLAGS
-CPP
-CPPFLAGS'
+CPP'
 
 
 # Initialize some variables set by options.
@@ -1307,7 +1308,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures libpng 1.5.3beta02 to adapt to many kinds of systems.
+\`configure' configures libpng 1.5.6beta02 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1377,7 +1378,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of libpng 1.5.3beta02:";;
+     short | recursive ) echo "Configuration of libpng 1.5.6beta02:";;
    esac
   cat <<\_ACEOF
 
@@ -1485,7 +1486,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-libpng configure 1.5.3beta02
+libpng configure 1.5.6beta02
 generated by GNU Autoconf 2.68
 
 Copyright (C) 2010 Free Software Foundation, Inc.
@@ -1908,7 +1909,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by libpng $as_me 1.5.3beta02, which was
+It was created by libpng $as_me 1.5.6beta02, which was
 generated by GNU Autoconf 2.68.  Invocation command line was
 
   $ $0 $@
@@ -2723,7 +2724,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='libpng'
- VERSION='1.5.3beta02'
+ VERSION='1.5.6beta02'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -2787,10 +2788,10 @@ fi
 
 
 
-PNGLIB_VERSION=1.5.3beta02
+PNGLIB_VERSION=1.5.6beta02
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=5
-PNGLIB_RELEASE=3
+PNGLIB_RELEASE=6
 
 
 
@@ -12408,6 +12409,28 @@ LIBPNG_DEFINES=$LIBPNG_DEFINES
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking if libraries can be versioned" >&5
 $as_echo_n "checking if libraries can be versioned... " >&6; }
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if using Solaris linker" >&5
+$as_echo_n "checking if using Solaris linker... " >&6; }
+SLD=`$LD --version 2>&1 | grep Solaris`
+if test "$SLD"; then
+    have_solaris_ld=yes
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+    have_solaris_ld=no
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+ if test "$have_solaris_ld" = "yes"; then
+  HAVE_SOLARIS_LD_TRUE=
+  HAVE_SOLARIS_LD_FALSE='#'
+else
+  HAVE_SOLARIS_LD_TRUE='#'
+  HAVE_SOLARIS_LD_FALSE=
+fi
+
+
 # Special case for PE/COFF platforms: ld reports
 # support for version-script, but doesn't actually
 # DO anything with it.
@@ -12418,7 +12441,13 @@ case $host in
 $as_echo "no" >&6; }
 ;;
 * )
-GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script`
+
+if test "$have_solaris_ld" = "yes"; then
+    GLD=`$LD --help < /dev/null 2>&1 | grep 'M mapfile'`
+else
+    GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script`
+fi
+
 if test "$GLD"; then
     have_ld_version_script=yes
     { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
@@ -12627,6 +12656,10 @@ if test -z "${am__fastdepCC_TRUE}" && test -z "${am__fastdepCC_FALSE}"; then
   as_fn_error $? "conditional \"am__fastdepCC\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
 fi
+if test -z "${HAVE_SOLARIS_LD_TRUE}" && test -z "${HAVE_SOLARIS_LD_FALSE}"; then
+  as_fn_error $? "conditional \"HAVE_SOLARIS_LD\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
 if test -z "${HAVE_LD_VERSION_SCRIPT_TRUE}" && test -z "${HAVE_LD_VERSION_SCRIPT_FALSE}"; then
   as_fn_error $? "conditional \"HAVE_LD_VERSION_SCRIPT\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
@@ -13040,7 +13073,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by libpng $as_me 1.5.3beta02, which was
+This file was extended by libpng $as_me 1.5.6beta02, which was
 generated by GNU Autoconf 2.68.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -13106,7 +13139,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-libpng config.status 1.5.3beta02
+libpng config.status 1.5.6beta02
 configured by $0, generated by GNU Autoconf 2.68,
   with options \\"\$ac_cs_config\\"
 

configure.ac

@@ -18,15 +18,15 @@ AC_PREREQ(2.59)
 
 dnl Version number stuff here:
 
-AC_INIT([libpng], [1.5.3beta02], [png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng], [1.5.6beta02], [png-mng-implement@lists.sourceforge.net])
 AM_INIT_AUTOMAKE
 dnl stop configure from automagically running automake
 AM_MAINTAINER_MODE
 
-PNGLIB_VERSION=1.5.3beta02
+PNGLIB_VERSION=1.5.6beta02
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=5
-PNGLIB_RELEASE=3
+PNGLIB_RELEASE=6
 
 dnl End of version number stuff
 
@@ -95,6 +95,18 @@ LIBPNG_DEFINES=$LIBPNG_DEFINES
 AC_SUBST(LIBPNG_DEFINES)
 
 AC_MSG_CHECKING([if libraries can be versioned])
+
+AC_MSG_CHECKING([if using Solaris linker])
+SLD=`$LD --version 2>&1 | grep Solaris`
+if test "$SLD"; then
+    have_solaris_ld=yes
+    AC_MSG_RESULT(yes)
+else
+    have_solaris_ld=no
+    AC_MSG_RESULT(no)
+fi
+AM_CONDITIONAL(HAVE_SOLARIS_LD, test "$have_solaris_ld" = "yes")
+
 # Special case for PE/COFF platforms: ld reports
 # support for version-script, but doesn't actually
 # DO anything with it.
@@ -104,7 +116,13 @@ case $host in
     AC_MSG_RESULT(no)
 ;;
 * )
-GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script`
+
+if test "$have_solaris_ld" = "yes"; then
+    GLD=`$LD --help < /dev/null 2>&1 | grep 'M mapfile'`
+else
+    GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script`
+fi
+
 if test "$GLD"; then
     have_ld_version_script=yes
     AC_MSG_RESULT(yes)

contrib/gregbook/Makefile.w32

@@ -18,7 +18,7 @@
 # "c:\windows\command.com /e:4096" as the program command line and set the
 # working directory to this directory.  Then double-click to open the new
 # DOS-prompt window with a bigger environment and retry the commands above.
-# 
+#
 # This makefile assumes libpng and zlib have already been built or downloaded
 # and are in subdirectories at the same level as the current subdirectory
 # (as indicated by the PNGPATH and ZPATH macros below).  Edit as appropriate.

contrib/gregbook/README

@@ -104,7 +104,7 @@ BUILD INSTRUCTIONS
      unpacked the source code.
 
      For MSVC, set up the necessary environment variables by invoking
- 
+
         %devstudio%\vc\bin\vcvars32.bat
 
      where where %devstudio% is the installation directory for MSVC /

contrib/gregbook/makevms.com

@@ -20,13 +20,13 @@ $ if zpath .eqs. ""
 $ then
 $   write sys$output "zlib include not found. Exiting..."
 $   exit 2
-$ endif 
+$ endif
 $!
 $ if pngpath .eqs. ""
 $ then
 $   write sys$output "libpng include not found. Exiting..."
 $   exit 2
-$ endif 
+$ endif
 $!
 $!    Look for the compiler used.
 $!

contrib/gregbook/readpng.c

@@ -229,8 +229,14 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
         png_set_expand(png_ptr);
     if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
         png_set_expand(png_ptr);
+#ifdef PNG_READ_16_TO_8_SUPPORTED
     if (bit_depth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
         png_set_strip_16(png_ptr);
+#  endif
+#endif
     if (color_type == PNG_COLOR_TYPE_GRAY ||
         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
         png_set_gray_to_rgb(png_ptr);

contrib/gregbook/readpng2.c

@@ -311,8 +311,14 @@ static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
         png_set_expand(png_ptr);
     if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
         png_set_expand(png_ptr);
+#ifdef PNG_READ_16_TO_8_SUPPORTED
     if (bit_depth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
         png_set_strip_16(png_ptr);
+#  endif
+#endif
     if (color_type == PNG_COLOR_TYPE_GRAY ||
         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
         png_set_gray_to_rgb(png_ptr);

contrib/gregbook/rpng-x.c

@@ -252,8 +252,8 @@ int main(int argc, char **argv)
             else {
                 bgstr = *argv;
                 if (strlen(bgstr) != 7 || bgstr[0] != '#')
-                    ++error; 
-                else 
+                    ++error;
+                else
                     have_bg = TRUE;
             }
         } else {

contrib/pngminim/decoder/README

@@ -7,4 +7,4 @@ Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC
 on the make command line.
 
 If you prefer to use the shared libraries, go to contrib/pngminus
-and build the png2pnm application there. 
+and build the png2pnm application there.

contrib/pngminim/decoder/pngusr.dfa

@@ -36,4 +36,4 @@ option FLOATING_ARITHMETIC off
 option SETJMP on
 option STDIO on
 option READ_EXPAND on
-option READ_16_TO_8 on
+option READ_STRIP_16_TO_8 on

contrib/pngminim/encoder/README

@@ -7,4 +7,4 @@ Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC
 on the make command line.
 
 If you prefer to use the shared libraries, go to contrib/pngminus
-and build the pnm2png application there. 
+and build the pnm2png application there.

contrib/pngminim/preader/README

@@ -8,8 +8,8 @@ on the make command line.
 
 Edit makefile if required, to find your X library and include files,
 then
-    
+
     make ZLIBSRC=directory
- 
+
 If you prefer to use the shared libraries, go to contrib/gregbook
-and build the rpng2-x application there. 
+and build the rpng2-x application there.

contrib/pngminim/preader/pngusr.dfa

@@ -36,5 +36,5 @@ option STDIO on
 option READ_bKGD on
 option READ_GAMMA on
 option READ_EXPAND on
-option READ_16_TO_8 on
+option READ_STRIP_16_TO_8 on
 option READ_GRAY_TO_RGB on

contrib/pngminus/makefile.std

@@ -8,9 +8,9 @@ LD=$(CC)
 RM=rm -f
 
 #PNGPATH = /usr/local
-#PNGINC = -I$(PNGPATH)/include/libpng12
-#PNGLIB = -L$(PNGPATH)/lib -lpng12
-#PNGLIBS = $(PNGPATH)/lib/libpng12.a
+#PNGINC = -I$(PNGPATH)/include/libpng15
+#PNGLIB = -L$(PNGPATH)/lib -lpng15
+#PNGLIBS = $(PNGPATH)/lib/libpng15.a
 PNGINC = -I../..
 PNGLIB = -L../.. -lpng
 PNGLIBS = ../../libpng.a
@@ -23,9 +23,9 @@ ZINC = -I../../../zlib
 ZLIB = -L../../../zlib -lz
 ZLIBS = ../../../zlib/libz.a
 
-CFLAGS=-O3 $(PNGINC) $(ZINC)
-LDFLAGS=$(PNGLIB) $(ZLIB)
-LDFLAGSS=$(PNGLIBS) $(ZLIBS)
+CFLAGS=$(PNGINC) $(ZINC)
+LDLIBS=$(PNGLIB) $(ZLIB)
+LDLIBSS=$(PNGLIBS) $(ZLIBS)
 C=.c
 O=.o
 L=.a
@@ -40,19 +40,19 @@ png2pnm$(O): png2pnm$(C)
 	$(CC) -c $(CFLAGS) png2pnm$(C)
 
 png2pnm$(E): png2pnm$(O)
-	$(LD) -o png2pnm$(E) png2pnm$(O) $(LDFLAGS) -lm
+	$(LD) $(LDFLAGS) -o png2pnm$(E) png2pnm$(O) $(LDLIBS) -lm
 
 png2pnm-static$(E): png2pnm$(O)
-	$(LD) -o png2pnm-static$(E) png2pnm$(O) $(LDFLAGSS) -lm
+	$(LD) $(LDFLAGS) -o png2pnm-static$(E) png2pnm$(O) $(LDLIBSS) -lm
 
 pnm2png$(O): pnm2png$(C)
 	$(CC) -c $(CFLAGS) pnm2png$(C)
 
 pnm2png$(E): pnm2png$(O)
-	$(LD) -o pnm2png$(E) pnm2png$(O) $(LDFLAGS) -lm
+	$(LD) $(LDFLAGS) -o pnm2png$(E) pnm2png$(O) $(LDLIBS) -lm
 
 pnm2png-static$(E): pnm2png$(O)
-	$(LD) -o pnm2png-static$(E) pnm2png$(O) $(LDFLAGSS) -lm
+	$(LD) $(LDFLAGS) -o pnm2png-static$(E) pnm2png$(O) $(LDLIBSS) -lm
 
 clean:
 	$(RM) png2pnm$(O)

contrib/pngminus/png2pnm.c

@@ -144,7 +144,7 @@ int main(int argc, char *argv[])
   if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
   {
     fprintf (stderr, "PNG2PNM\n");
-    fprintf (stderr, "Error:  unsuccessful convertion of PNG-image\n");
+    fprintf (stderr, "Error:  unsuccessful conversion of PNG-image\n");
     exit(1);
   }
 
@@ -403,7 +403,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
             if (bit_depth == 16){
               dep_16 = (long) *pix_ptr++;
               fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
-            }  
+            }
             else
               fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
         }

contrib/pngsuite/README

@@ -6,9 +6,9 @@ pngsuite
 Permission to use, copy, modify, and distribute these images for any
 purpose and without fee is hereby granted.
 
-The 15 "bas*.png" images are part of the much larger PngSuite test-set of 
-images, available for developers of PNG supporting software. The 
-complete set, available at http:/www.schaik.com/pngsuite/, contains 
+The 15 "bas*.png" images are part of the much larger PngSuite test-set of
+images, available for developers of PNG supporting software. The
+complete set, available at http:/www.schaik.com/pngsuite/, contains
 a variety of images to test interlacing, gamma settings, ancillary
 chunks, etc.
 
@@ -48,7 +48,7 @@ can use them to test the proper functioning of PNG software.
     ftbwn3p08.png  8-bit paletted, white bKGD
     ftbyn3p08.png  8-bit paletted, yellow bKGD
     ftp0n0g08.png  8-bit grayscale, opaque
-    ftp0n2c08.png  8-bit truecolor, opaque 
+    ftp0n2c08.png  8-bit truecolor, opaque
     ftp0n3p08.png  8-bit paletted, opaque
     ftp1n3p08.png  8-bit paletted, no bKGD
 

contrib/visupng/PngFile.c

@@ -1,12 +1,13 @@
-//-------------------------------------
-//  PNGFILE.C -- Image File Functions
-//-------------------------------------
-
-// Copyright 2000, Willem van Schaik.
-//
-// This code is released under the libpng license.
-// For conditions of distribution and use, see the disclaimer
-// and license in png.h
+/*-------------------------------------
+ *  PNGFILE.C -- Image File Functions
+ *-------------------------------------
+ *
+ * Copyright 2000, Willem van Schaik.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
 
 #include <windows.h>
 #include <commdlg.h>
@@ -28,7 +29,7 @@ static png_structp png_ptr = NULL;
 static png_infop info_ptr = NULL;
 
 
-// cexcept interface
+/* cexcept interface */
 
 static void
 png_cexcept_error(png_structp png_ptr, png_const_charp msg)
@@ -43,7 +44,7 @@ png_cexcept_error(png_structp png_ptr, png_const_charp msg)
    }
 }
 
-// Windows open-file functions
+/* Windows open-file functions */
 
 void PngFileInitialize (HWND hwnd)
 {
@@ -57,13 +58,13 @@ void PngFileInitialize (HWND hwnd)
     ofn.lpstrCustomFilter = NULL;
     ofn.nMaxCustFilter    = 0;
     ofn.nFilterIndex      = 0;
-    ofn.lpstrFile         = NULL;          // Set in Open and Close functions
+    ofn.lpstrFile         = NULL;          /* Set in Open and Close functions */
     ofn.nMaxFile          = MAX_PATH;
-    ofn.lpstrFileTitle    = NULL;          // Set in Open and Close functions
+    ofn.lpstrFileTitle    = NULL;          /* Set in Open and Close functions */
     ofn.nMaxFileTitle     = MAX_PATH;
     ofn.lpstrInitialDir   = NULL;
     ofn.lpstrTitle        = NULL;
-    ofn.Flags             = 0;             // Set in Open and Close functions
+    ofn.Flags             = 0;             /* Set in Open and Close functions */
     ofn.nFileOffset       = 0;
     ofn.nFileExtension    = 0;
     ofn.lpstrDefExt       = TEXT ("png");
@@ -92,7 +93,7 @@ BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
     return GetSaveFileName (&ofn);
 }
 
-// PNG image handler functions
+/* PNG image handler functions */
 
 BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
                    int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor)
@@ -109,7 +110,7 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
     static png_byte   **ppbRowPointers = NULL;
     int                 i;
 
-    // open the PNG input file
+    /* open the PNG input file */
 
     if (!pstrFileName)
     {
@@ -123,7 +124,7 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
         return FALSE;
     }
 
-    // first check the eight byte PNG signature
+    /* first check the eight byte PNG signature */
 
     fread(pbSig, 1, 8, pfFile);
     if (png_sig_cmp(pbSig, 0, 8))
@@ -132,7 +133,7 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
         return FALSE;
     }
 
-    // create the two png(-info) structures
+    /* create the two png(-info) structures */
 
     png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL,
       (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
@@ -152,31 +153,37 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
 
     Try
     {
-        
-        // initialize the png structure
-        
+
+        /* initialize the png structure */
+
 #ifdef PNG_STDIO_SUPPORTED
         png_init_io(png_ptr, pfFile);
 #else
         png_set_read_fn(png_ptr, (png_voidp)pfFile, png_read_data);
 #endif
-        
+
         png_set_sig_bytes(png_ptr, 8);
-        
-        // read all PNG info up to image data
-        
+
+        /* read all PNG info up to image data */
+
         png_read_info(png_ptr, info_ptr);
-        
-        // get width, height, bit-depth and color-type
-        
+
+        /* get width, height, bit-depth and color-type */
+
         png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
             &iColorType, NULL, NULL, NULL);
-        
-        // expand images of all color-type and bit-depth to 3x8 bit RGB images
-        // let the library process things like alpha, transparency, background
-        
-        if (iBitDepth == 16)
-            png_set_strip_16(png_ptr);
+
+        /* expand images of all color-type and bit-depth to 3x8-bit RGB */
+        /* let the library process alpha, transparency, background, etc. */
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+    if (iBitDepth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
+        png_set_strip_16(png_ptr);
+#  endif
+#endif
         if (iColorType == PNG_COLOR_TYPE_PALETTE)
             png_set_expand(png_ptr);
         if (iBitDepth < 8)
@@ -186,8 +193,8 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
         if (iColorType == PNG_COLOR_TYPE_GRAY ||
             iColorType == PNG_COLOR_TYPE_GRAY_ALPHA)
             png_set_gray_to_rgb(png_ptr);
-        
-        // set the background color to draw transparent and alpha images over.
+
+        /* set the background color to draw transparent and alpha images over */
         if (png_get_bKGD(png_ptr, info_ptr, &pBackground))
         {
             png_set_background(png_ptr, pBackground, PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
@@ -199,30 +206,30 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
         {
             pBkgColor = NULL;
         }
-        
-        // if required set gamma conversion
+
+        /* if required set gamma conversion */
         if (png_get_gAMA(png_ptr, info_ptr, &dGamma))
             png_set_gamma(png_ptr, (double) 2.2, dGamma);
-        
-        // after the transformations have been registered update info_ptr data
-        
+
+        /* after the transformations are registered, update info_ptr data */
+
         png_read_update_info(png_ptr, info_ptr);
-        
-        // get again width, height and the new bit-depth and color-type
-        
+
+        /* get again width, height and the new bit-depth and color-type */
+
         png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
             &iColorType, NULL, NULL, NULL);
-        
-        
-        // row_bytes is the width x number of channels
-        
+
+
+        /* row_bytes is the width x number of channels */
+
         ulRowBytes = png_get_rowbytes(png_ptr, info_ptr);
         ulChannels = png_get_channels(png_ptr, info_ptr);
-        
+
         *piChannels = ulChannels;
-        
-        // now we can allocate memory to store the image
-        
+
+        /* now we can allocate memory to store the image */
+
         if (pbImageData)
         {
             free (pbImageData);
@@ -234,34 +241,34 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
             png_error(png_ptr, "Visual PNG: out of memory");
         }
         *ppbImageData = pbImageData;
-        
-        // and allocate memory for an array of row-pointers
-        
+
+        /* and allocate memory for an array of row-pointers */
+
         if ((ppbRowPointers = (png_bytepp) malloc((*piHeight)
                             * sizeof(png_bytep))) == NULL)
         {
             png_error(png_ptr, "Visual PNG: out of memory");
         }
-        
-        // set the individual row-pointers to point at the correct offsets
-        
+
+        /* set the individual row-pointers to point at the correct offsets */
+
         for (i = 0; i < (*piHeight); i++)
             ppbRowPointers[i] = pbImageData + i * ulRowBytes;
-        
-        // now we can go ahead and just read the whole image
-        
+
+        /* now we can go ahead and just read the whole image */
+
         png_read_image(png_ptr, ppbRowPointers);
-        
-        // read the additional chunks in the PNG file (not really needed)
-        
+
+        /* read the additional chunks in the PNG file (not really needed) */
+
         png_read_end(png_ptr, NULL);
-        
-        // and we're done
-        
+
+        /* and we're done */
+
         free (ppbRowPointers);
         ppbRowPointers = NULL;
-        
-        // yepp, done
+
+        /* yepp, done */
     }
 
     Catch (msg)
@@ -269,7 +276,7 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
         png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
 
         *ppbImageData = pbImageData = NULL;
-        
+
         if(ppbRowPointers)
             free (ppbRowPointers);
 
@@ -295,7 +302,7 @@ BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
     static png_byte   **ppbRowPointers = NULL;
     int                 i;
 
-    // open the PNG output file
+    /* open the PNG output file */
 
     if (!pstrFileName)
         return FALSE;
@@ -303,7 +310,7 @@ BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
     if (!(pfFile = fopen(pstrFileName, "wb")))
         return FALSE;
 
-    // prepare the standard PNG structures
+    /* prepare the standard PNG structures */
 
     png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
       (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
@@ -322,60 +329,60 @@ BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
 
     Try
     {
-        // initialize the png structure
-        
+        /* initialize the png structure */
+
 #ifdef PNG_STDIO_SUPPORTED
         png_init_io(png_ptr, pfFile);
 #else
         png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush);
 #endif
-        
-        // we're going to write a very simple 3x8 bit RGB image
-        
+
+        /* we're going to write a very simple 3x8-bit RGB image */
+
         png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight, ciBitDepth,
             PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
             PNG_FILTER_TYPE_BASE);
-        
-        // write the file header information
-        
+
+        /* write the file header information */
+
         png_write_info(png_ptr, info_ptr);
-        
-        // swap the BGR pixels in the DiData structure to RGB
-        
+
+        /* swap the BGR pixels in the DiData structure to RGB */
+
         png_set_bgr(png_ptr);
-        
-        // row_bytes is the width x number of channels
-        
+
+        /* row_bytes is the width x number of channels */
+
         ulRowBytes = iWidth * ciChannels;
-        
-        // we can allocate memory for an array of row-pointers
-        
+
+        /* we can allocate memory for an array of row-pointers */
+
         if ((ppbRowPointers = (png_bytepp) malloc(iHeight * sizeof(png_bytep))) == NULL)
             Throw "Visualpng: Out of memory";
-        
-        // set the individual row-pointers to point at the correct offsets
-        
+
+        /* set the individual row-pointers to point at the correct offsets */
+
         for (i = 0; i < iHeight; i++)
             ppbRowPointers[i] = pDiData + i * (((ulRowBytes + 3) >> 2) << 2);
-        
-        // write out the entire image data in one call
-        
+
+        /* write out the entire image data in one call */
+
         png_write_image (png_ptr, ppbRowPointers);
-        
-        // write the additional chunks to the PNG file (not really needed)
-        
+
+        /* write the additional chunks to the PNG file (not really needed) */
+
         png_write_end(png_ptr, info_ptr);
-        
-        // and we're done
-        
+
+        /* and we're done */
+
         free (ppbRowPointers);
         ppbRowPointers = NULL;
-        
-        // clean up after the write, and free any memory allocated
-        
+
+        /* clean up after the write, and free any memory allocated */
+
         png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
-        
-        // yepp, done
+
+        /* yepp, done */
     }
 
     Catch (msg)
@@ -389,9 +396,9 @@ BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
 
         return FALSE;
     }
-    
+
     fclose (pfFile);
-    
+
     return TRUE;
 }
 
@@ -437,6 +444,7 @@ png_flush(png_structp png_ptr)
 
 #endif
 
-//-----------------
-//  end of source
-//-----------------
+/*-----------------
+ *  end of source
+ *-----------------
+ */

contrib/visupng/PngFile.h

@@ -1,12 +1,12 @@
-//------------------------------------------
-//  PNGFILE.H -- Header File for pngfile.c
-//------------------------------------------
+/*------------------------------------------*/
+/*  PNGFILE.H -- Header File for pngfile.c*/
+/*------------------------------------------*/
 
-// Copyright 2000, Willem van Schaik.
+/* Copyright 2000, Willem van Schaik.*/
 
-// This code is released under the libpng license.
-// For conditions of distribution and use, see the disclaimer
-// and license in png.h
+/* This code is released under the libpng license.*/
+/* For conditions of distribution and use, see the disclaimer*/
+/* and license in png.h*/
 
 #include <stdio.h>
 #include <stdlib.h>

contrib/visupng/README.txt

@@ -8,8 +8,8 @@ For conditions of distribution and use, see the disclaimer
 and license in png.h
 
 As a PNG .dll demo VisualPng is finished. More features would only hinder
-the program's objective. However, further extensions (like support for other 
-graphics formats) are in development. To get these, or for pre-compiled 
+the program's objective. However, further extensions (like support for other
+graphics formats) are in development. To get these, or for pre-compiled
 binaries, go to "http://www.schaik.com/png/visualpng.html".
 
 ------------------------------------------------------------------------

contrib/visupng/VisualPng.c

@@ -1,41 +1,42 @@
-//------------------------------------
-//  VisualPng.C -- Shows a PNG image
-//------------------------------------
+/*------------------------------------
+ *  VisualPng.C -- Shows a PNG image
+ *------------------------------------
+ *
+ * Copyright 2000, Willem van Schaik.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
 
-// Copyright 2000, Willem van Schaik.
+/* switches */
 
-// This code is released under the libpng license.
-// For conditions of distribution and use, see the disclaimer
-// and license in png.h
-
-// switches
-
-// defines
+/* defines */
 
 #define PROGNAME  "VisualPng"
 #define LONGNAME  "Win32 Viewer for PNG-files"
 #define VERSION   "1.0 of 2000 June 07"
 
-// constants
+/* constants */
 
 #define MARGIN 8
 
-// standard includes
+/* standard includes */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <windows.h>
 
-// application includes
+/* application includes */
 
 #include "png.h"
 #include "pngfile.h"
 #include "resource.h"
 
-// macros
+/* macros */
 
-// function prototypes
+/* function prototypes */
 
 LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);
 BOOL    CALLBACK AboutDlgProc (HWND, UINT, WPARAM, LPARAM) ;
@@ -65,14 +66,14 @@ BOOL FillBitmap (
         BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
         BOOL bStretched);
 
-// a few global variables
+/* a few global variables */
 
 static char *szProgName = PROGNAME;
 static char *szAppName = LONGNAME;
 static char *szIconName = PROGNAME;
 static char szCmdFileName [MAX_PATH];
 
-// MAIN routine
+/* MAIN routine */
 
 int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                     PSTR szCmdLine, int iCmdShow)
@@ -90,7 +91,7 @@ int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
     wndclass.hInstance     = hInstance;
     wndclass.hIcon         = LoadIcon (hInstance, szIconName) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW);
-    wndclass.hbrBackground = NULL; // (HBRUSH) GetStockObject (GRAY_BRUSH);
+    wndclass.hbrBackground = NULL; /* (HBRUSH) GetStockObject (GRAY_BRUSH); */
     wndclass.lpszMenuName  = szProgName;
     wndclass.lpszClassName = szProgName;
 
@@ -101,7 +102,7 @@ int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
         return 0;
     }
 
-    // if filename given on commandline, store it
+    /* if filename given on commandline, store it */
     if ((szCmdLine != NULL) && (*szCmdLine != '\0'))
         if (szCmdLine[0] == '"')
             strncpy (szCmdFileName, szCmdLine + 1, strlen(szCmdLine) - 2);
@@ -110,20 +111,20 @@ int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
     else
         strcpy (szCmdFileName, "");
 
-    // calculate size of window-borders
+    /* calculate size of window-borders */
     ixBorders = 2 * (GetSystemMetrics (SM_CXBORDER) +
                      GetSystemMetrics (SM_CXDLGFRAME));
     iyBorders = 2 * (GetSystemMetrics (SM_CYBORDER) +
                      GetSystemMetrics (SM_CYDLGFRAME)) +
                      GetSystemMetrics (SM_CYCAPTION) +
                      GetSystemMetrics (SM_CYMENUSIZE) +
-                     1; /* WvS: don't ask me why? */
+                     1; /* WvS: don't ask me why?  */
 
     hwnd = CreateWindow (szProgName, szAppName,
         WS_OVERLAPPEDWINDOW,
         CW_USEDEFAULT, CW_USEDEFAULT,
         512 + 2 * MARGIN + ixBorders, 384 + 2 * MARGIN + iyBorders,
-//      CW_USEDEFAULT, CW_USEDEFAULT,
+/*      CW_USEDEFAULT, CW_USEDEFAULT, */
         NULL, NULL, hInstance, NULL);
 
     ShowWindow (hwnd, iCmdShow);
@@ -180,29 +181,29 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
 
         strcpy (szImgPathName, "");
 
-        // in case we process file given on command-line
+        /* in case we process file given on command-line */
 
         if (szCmdFileName[0] != '\0')
         {
             strcpy (szImgPathName, szCmdFileName);
 
-            // read the other png-files in the directory for later
-            // next/previous commands
+            /* read the other png-files in the directory for later */
+            /* next/previous commands */
 
             BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
                           &iPngFileIndex);
 
-            // load the image from file
+            /* load the image from file */
 
             if (!LoadImageFile (hwnd, szImgPathName,
                 &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
                 return 0;
 
-            // invalidate the client area for later update
+            /* invalidate the client area for later update */
 
             InvalidateRect (hwnd, NULL, TRUE);
 
-            // display the PNG into the DIBitmap
+            /* display the PNG into the DIBitmap */
 
             DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
                 pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
@@ -214,11 +215,11 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
         cxWinSize = LOWORD (lParam);
         cyWinSize = HIWORD (lParam);
 
-        // invalidate the client area for later update
+        /* invalidate the client area for later update */
 
         InvalidateRect (hwnd, NULL, TRUE);
 
-        // display the PNG into the DIBitmap
+        /* display the PNG into the DIBitmap */
 
         DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
             pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
@@ -242,28 +243,28 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
         {
         case IDM_FILE_OPEN:
 
-            // show the File Open dialog box
+            /* show the File Open dialog box */
 
             if (!PngFileOpenDlg (hwnd, szImgPathName, szTitleName))
                 return 0;
 
-            // read the other png-files in the directory for later
-            // next/previous commands
+            /* read the other png-files in the directory for later */
+            /* next/previous commands */
 
             BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
                           &iPngFileIndex);
 
-            // load the image from file
+            /* load the image from file */
 
             if (!LoadImageFile (hwnd, szImgPathName,
                 &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
                 return 0;
 
-            // invalidate the client area for later update
+            /* invalidate the client area for later update */
 
             InvalidateRect (hwnd, NULL, TRUE);
 
-            // display the PNG into the DIBitmap
+            /* display the PNG into the DIBitmap */
 
             DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
                 pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
@@ -272,12 +273,12 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
 
         case IDM_FILE_SAVE:
 
-            // show the File Save dialog box
+            /* show the File Save dialog box */
 
             if (!PngFileSaveDlg (hwnd, szImgPathName, szTitleName))
                 return 0;
 
-            // save the PNG to a disk file
+            /* save the PNG to a disk file */
 
             SetCursor (LoadCursor (NULL, IDC_WAIT));
             ShowCursor (TRUE);
@@ -295,55 +296,55 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
 
         case IDM_FILE_NEXT:
 
-            // read next entry in the directory
+            /* read next entry in the directory */
 
             if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
                 NULL, szImgPathName))
             {
                 if (strcmp (szImgPathName, "") == 0)
                     return 0;
-                
-                // load the image from file
-                
+
+                /* load the image from file */
+
                 if (!LoadImageFile (hwnd, szImgPathName, &pbImage,
                         &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
                     return 0;
-                
-                // invalidate the client area for later update
-                
+
+                /* invalidate the client area for later update */
+
                 InvalidateRect (hwnd, NULL, TRUE);
-                
-                // display the PNG into the DIBitmap
-                
+
+                /* display the PNG into the DIBitmap */
+
                 DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
                     pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
             }
-            
+
             return 0;
 
         case IDM_FILE_PREVIOUS:
 
-            // read previous entry in the directory
+            /* read previous entry in the directory */
 
             if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
                 szImgPathName, NULL))
             {
-                
+
                 if (strcmp (szImgPathName, "") == 0)
                     return 0;
-                
-                // load the image from file
-                
+
+                /* load the image from file */
+
                 if (!LoadImageFile (hwnd, szImgPathName, &pbImage, &cxImgSize,
                     &cyImgSize, &cImgChannels, &bkgColor))
                     return 0;
-                
-                // invalidate the client area for later update
-                
+
+                /* invalidate the client area for later update */
+
                 InvalidateRect (hwnd, NULL, TRUE);
-                
-                // display the PNG into the DIBitmap
-                
+
+                /* display the PNG into the DIBitmap */
+
                 DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
                     pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
             }
@@ -352,9 +353,9 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
 
         case IDM_FILE_EXIT:
 
-            // more cleanup needed...
+            /* more cleanup needed... */
 
-            // free image buffer
+            /* free image buffer */
 
             if (pDib != NULL)
             {
@@ -362,7 +363,7 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
                 pDib = NULL;
             }
 
-            // free file-list
+            /* free file-list */
 
             if (pPngFileList != NULL)
             {
@@ -370,7 +371,7 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
                 pPngFileList = NULL;
             }
 
-            // let's go ...
+            /* let's go ... */
 
             exit (0);
 
@@ -383,11 +384,11 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
             else
                 CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_UNCHECKED);
 
-            // invalidate the client area for later update
+            /* invalidate the client area for later update */
 
             InvalidateRect (hwnd, NULL, TRUE);
 
-            // display the PNG into the DIBitmap
+            /* display the PNG into the DIBitmap */
 
             DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
                 pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
@@ -398,7 +399,7 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
             DialogBox (hInstance, TEXT ("AboutBox"), hwnd, AboutDlgProc) ;
             return 0;
 
-        } // end switch
+        } /* end switch */
 
         break;
 
@@ -450,10 +451,10 @@ BOOL CALLBACK AboutDlgProc (HWND hDlg, UINT message,
      return FALSE ;
 }
 
-//---------------
-//  CenterAbout
-//---------------
-
+/*---------------
+ *  CenterAbout
+ *---------------
+ */
 BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
 {
    RECT    rChild, rParent, rWorkArea;
@@ -461,19 +462,19 @@ BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
    int     xNew, yNew;
    BOOL  bResult;
 
-   // Get the Height and Width of the child window
+   /* Get the Height and Width of the child window */
    GetWindowRect (hwndChild, &rChild);
    wChild = rChild.right - rChild.left;
    hChild = rChild.bottom - rChild.top;
 
-   // Get the Height and Width of the parent window
+   /* Get the Height and Width of the parent window */
    GetWindowRect (hwndParent, &rParent);
    wParent = rParent.right - rParent.left;
    hParent = rParent.bottom - rParent.top;
 
-   // Get the limits of the 'workarea'
+   /* Get the limits of the 'workarea' */
    bResult = SystemParametersInfo(
-      SPI_GETWORKAREA,  // system parameter to query or set
+      SPI_GETWORKAREA,  /* system parameter to query or set */
       sizeof(RECT),
       &rWorkArea,
       0);
@@ -483,7 +484,7 @@ BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
       rWorkArea.bottom = GetSystemMetrics(SM_CYSCREEN);
    }
 
-   // Calculate new X position, then adjust for workarea
+   /* Calculate new X position, then adjust for workarea */
    xNew = rParent.left + ((wParent - wChild) /2);
    if (xNew < rWorkArea.left) {
       xNew = rWorkArea.left;
@@ -491,7 +492,7 @@ BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
       xNew = rWorkArea.right - wChild;
    }
 
-   // Calculate new Y position, then adjust for workarea
+   /* Calculate new Y position, then adjust for workarea */
    yNew = rParent.top  + ((hParent - hChild) /2);
    if (yNew < rWorkArea.top) {
       yNew = rWorkArea.top;
@@ -499,15 +500,15 @@ BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
       yNew = rWorkArea.bottom - hChild;
    }
 
-   // Set it, and return
+   /* Set it, and return */
    return SetWindowPos (hwndChild, NULL, xNew, yNew, 0, 0, SWP_NOSIZE |
           SWP_NOZORDER);
 }
 
-//----------------
-//  BuildPngList
-//----------------
-
+/*----------------
+ *  BuildPngList
+ *----------------
+ */
 BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
      int *pFileIndex)
 {
@@ -523,7 +524,7 @@ BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
     int                       i, ii;
     int                       j, jj;
 
-    // free previous file-list
+    /* free previous file-list */
 
     if (*ppFileList != NULL)
     {
@@ -531,7 +532,7 @@ BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
         *ppFileList = NULL;
     }
 
-    // extract foldername, filename and search-name
+    /* extract foldername, filename and search-name */
 
     strcpy (szImgPathName, pstrPathName);
     strcpy (szImgFileName, strrchr (pstrPathName, '\\') + 1);
@@ -540,7 +541,7 @@ BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
     *(strrchr (szImgFindName, '\\') + 1) = '\0';
     strcat (szImgFindName, "*.png");
 
-    // first cycle: count number of files in directory for memory allocation
+    /* first cycle: count number of files in directory for memory allocation */
 
     *pFileCount = 0;
 
@@ -554,11 +555,11 @@ BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
     }
     FindClose(hFind);
 
-    // allocation memory for file-list
+    /* allocation memory for file-list */
 
     *ppFileList = (TCHAR *) malloc (*pFileCount * MAX_PATH);
 
-    // second cycle: read directory and store filenames in file-list
+    /* second cycle: read directory and store filenames in file-list */
 
     hFind = FindFirstFile(szImgFindName, &finddata);
     bOk = (hFind != (HANDLE) -1);
@@ -580,7 +581,7 @@ BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
     }
     FindClose(hFind);
 
-    // finally we must sort the file-list
+    /* finally we must sort the file-list */
 
     for (i = 0; i < *pFileCount - 1; i++)
     {
@@ -594,7 +595,7 @@ BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
                 strcpy (*ppFileList + jj, *ppFileList + ii);
                 strcpy (*ppFileList + ii, szTmp);
 
-                // check if this was the current image that we moved
+                /* check if this was the current image that we moved */
 
                 if (*pFileIndex == i)
                     *pFileIndex = j;
@@ -608,9 +609,10 @@ BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
     return TRUE;
 }
 
-//----------------
-//  SearchPngList
-//----------------
+/*----------------
+ *  SearchPngList
+ *----------------
+ */
 
 BOOL SearchPngList (
         TCHAR *pFileList, int FileCount, int *pFileIndex,
@@ -618,30 +620,30 @@ BOOL SearchPngList (
 {
     if (FileCount > 0)
     {
-        // get previous entry
-        
+        /* get previous entry */
+
         if (pstrPrevName != NULL)
         {
             if (*pFileIndex > 0)
                 *pFileIndex -= 1;
             else
                 *pFileIndex = FileCount - 1;
-            
+
             strcpy (pstrPrevName, pFileList + (*pFileIndex * MAX_PATH));
         }
-        
-        // get next entry
-        
+
+        /* get next entry */
+
         if (pstrNextName != NULL)
         {
             if (*pFileIndex < FileCount - 1)
                 *pFileIndex += 1;
             else
                 *pFileIndex = 0;
-            
+
             strcpy (pstrNextName, pFileList + (*pFileIndex * MAX_PATH));
         }
-        
+
         return TRUE;
     }
     else
@@ -650,9 +652,10 @@ BOOL SearchPngList (
     }
 }
 
-//-----------------
-//  LoadImageFile
-//-----------------
+/*-----------------
+ *  LoadImageFile
+ *-----------------
+ */
 
 BOOL LoadImageFile (HWND hwnd, PTSTR pstrPathName,
                 png_byte **ppbImage, int *pxImgSize, int *pyImgSize,
@@ -660,7 +663,7 @@ BOOL LoadImageFile (HWND hwnd, PTSTR pstrPathName,
 {
     static TCHAR szTmp [MAX_PATH];
 
-    // if there's an existing PNG, free the memory
+    /* if there's an existing PNG, free the memory */
 
     if (*ppbImage)
     {
@@ -668,7 +671,7 @@ BOOL LoadImageFile (HWND hwnd, PTSTR pstrPathName,
         *ppbImage = NULL;
     }
 
-    // Load the entire PNG into memory
+    /* Load the entire PNG into memory */
 
     SetCursor (LoadCursor (NULL, IDC_WAIT));
     ShowCursor (TRUE);
@@ -694,10 +697,10 @@ BOOL LoadImageFile (HWND hwnd, PTSTR pstrPathName,
     return TRUE;
 }
 
-//----------------
-//  DisplayImage
-//----------------
-
+/*----------------
+ *  DisplayImage
+ *----------------
+ */
 BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
         BYTE **ppDiData, int cxWinSize, int cyWinSize,
         BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
@@ -705,14 +708,14 @@ BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
 {
     BYTE                       *pDib = *ppDib;
     BYTE                       *pDiData = *ppDiData;
-    // BITMAPFILEHEADER        *pbmfh;
+    /* BITMAPFILEHEADER        *pbmfh; */
     BITMAPINFOHEADER           *pbmih;
     WORD                        wDIRowBytes;
     png_color                   bkgBlack = {0, 0, 0};
     png_color                   bkgGray  = {127, 127, 127};
     png_color                   bkgWhite = {255, 255, 255};
 
-    // allocate memory for the Device Independant bitmap
+    /* allocate memory for the Device Independant bitmap */
 
     wDIRowBytes = (WORD) ((3 * cxWinSize + 3L) >> 2) << 2;
 
@@ -733,7 +736,7 @@ BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
     *ppDib = pDib;
     memset (pDib, 0, sizeof(BITMAPINFOHEADER));
 
-    // initialize the dib-structure
+    /* initialize the dib-structure */
 
     pbmih = (BITMAPINFOHEADER *) pDib;
     pbmih->biSize = sizeof(BITMAPINFOHEADER);
@@ -745,11 +748,11 @@ BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
     pDiData = pDib + sizeof(BITMAPINFOHEADER);
     *ppDiData = pDiData;
 
-    // first fill bitmap with gray and image border
+    /* first fill bitmap with gray and image border */
 
     InitBitmap (pDiData, cxWinSize, cyWinSize);
 
-    // then fill bitmap with image
+    /* then fill bitmap with image */
 
     if (pbImage)
     {
@@ -762,16 +765,16 @@ BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
     return TRUE;
 }
 
-//--------------
-//  InitBitmap
-//--------------
-
+/*--------------
+ *  InitBitmap
+ *--------------
+ */
 BOOL InitBitmap (BYTE *pDiData, int cxWinSize, int cyWinSize)
 {
     BYTE *dst;
     int x, y, col;
 
-    // initialize the background with gray
+    /* initialize the background with gray */
 
     dst = pDiData;
     for (y = 0; y < cyWinSize; y++)
@@ -779,13 +782,13 @@ BOOL InitBitmap (BYTE *pDiData, int cxWinSize, int cyWinSize)
         col = 0;
         for (x = 0; x < cxWinSize; x++)
         {
-            // fill with GRAY
+            /* fill with GRAY */
             *dst++ = 127;
             *dst++ = 127;
             *dst++ = 127;
             col += 3;
         }
-        // rows start on 4 byte boundaries
+        /* rows start on 4 byte boundaries */
         while ((col % 4) != 0)
         {
             dst++;
@@ -796,10 +799,10 @@ BOOL InitBitmap (BYTE *pDiData, int cxWinSize, int cyWinSize)
     return TRUE;
 }
 
-//--------------
-//  FillBitmap
-//--------------
-
+/*--------------
+ *  FillBitmap
+ *--------------
+ */
 BOOL FillBitmap (
         BYTE *pDiData, int cxWinSize, int cyWinSize,
         BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
@@ -824,11 +827,12 @@ BOOL FillBitmap (
         cxNewSize = cxWinSize - 2 * MARGIN;
         cyNewSize = cyWinSize - 2 * MARGIN;
 
-        // stretch the image to it's window determined size
+        /* stretch the image to it's window determined size */
 
-        // the following two are the same, but the first has side-effects
-        // because of rounding
-//      if ((cyNewSize / cxNewSize) > (cyImgSize / cxImgSize))
+        /* the following two are mathematically the same, but the first
+         * has side-effects because of rounding
+         */
+/*      if ((cyNewSize / cxNewSize) > (cyImgSize / cxImgSize)) */
         if ((cyNewSize * cxImgSize) > (cyImgSize * cxNewSize))
         {
             cyNewSize = cxNewSize * cyImgSize / cxImgSize;
@@ -867,12 +871,12 @@ BOOL FillBitmap (
             }
         }
 
-        // calculate row-bytes
+        /* calculate row-bytes */
 
         wImgRowBytes = cImgChannels * cxNewSize;
         wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
 
-        // copy image to screen
+        /* copy image to screen */
 
         for (yImg = 0, yWin = cyImgPos; yImg < cyNewSize; yImg++, yWin++)
         {
@@ -888,7 +892,7 @@ BOOL FillBitmap (
                 r = *src++;
                 g = *src++;
                 b = *src++;
-                *dst++ = b; /* note the reverse order */
+                *dst++ = b; /* note the reverse order  */
                 *dst++ = g;
                 *dst++ = r;
                 if (cImgChannels == 4)
@@ -898,7 +902,7 @@ BOOL FillBitmap (
             }
         }
 
-        // free memory
+        /* free memory */
 
         if (pStretchedImage != NULL)
         {
@@ -908,28 +912,28 @@ BOOL FillBitmap (
 
     }
 
-    // process the image not-stretched
+    /* process the image not-stretched */
 
     else
     {
-        // calculate the central position
+        /* calculate the central position */
 
         cxImgPos = (cxWinSize - cxImgSize) / 2;
         cyImgPos = (cyWinSize - cyImgSize) / 2;
 
-        // check for image larger than window
+        /* check for image larger than window */
 
         if (cxImgPos < MARGIN)
             cxImgPos = MARGIN;
         if (cyImgPos < MARGIN)
             cyImgPos = MARGIN;
 
-        // calculate both row-bytes
+        /* calculate both row-bytes */
 
         wImgRowBytes = cImgChannels * cxImgSize;
         wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
 
-        // copy image to screen
+        /* copy image to screen */
 
         for (yImg = 0, yWin = cyImgPos; yImg < cyImgSize; yImg++, yWin++)
         {
@@ -945,7 +949,7 @@ BOOL FillBitmap (
                 r = *src++;
                 g = *src++;
                 b = *src++;
-                *dst++ = b; /* note the reverse order */
+                *dst++ = b; /* note the reverse order  */
                 *dst++ = g;
                 *dst++ = r;
                 if (cImgChannels == 4)
@@ -959,6 +963,7 @@ BOOL FillBitmap (
     return TRUE;
 }
 
-//-----------------
-//  end of source
-//-----------------
+/*-----------------
+ *  end of source
+ *-----------------
+ */

contrib/visupng/resource.h

@@ -12,7 +12,7 @@
 #define IDM_HELP_ABOUT                  40008
 
 // Next default values for new objects
-// 
+//
 #ifdef APSTUDIO_INVOKED
 #ifndef APSTUDIO_READONLY_SYMBOLS
 #define _APS_NEXT_RESOURCE_VALUE        113

example.c

@@ -2,7 +2,7 @@
 #if 0 /* in case someone actually tries to compile this */
 
 /* example.c - an example of using libpng
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * This file has been placed in the public domain by the authors.
  * Maintained 1998-2011 Glenn Randers-Pehrson
  * Maintained 1996, 1997 Andreas Dilger)
@@ -22,6 +22,10 @@
  * see also the programs in the contrib directory.
  */
 
+#define _POSIX_SOURCE 1  /* libpng and zlib are POSIX-compliant.  You may
+                          * change this if your application uses non-POSIX
+                          * extensions. */
+
 #include "png.h"
 
  /* The png_jmpbuf() macro, used in error handling, became available in
@@ -183,8 +187,15 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
     * are mutually exclusive.
     */
 
-   /* Tell libpng to strip 16 bit/color files down to 8 bits/color */
+   /* Tell libpng to strip 16 bit/color files down to 8 bits/color.
+    * Use accurate scaling if it's available, otherwise just chop off the
+    * low byte.
+    */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+    png_set_scale_16(png_ptr);
+#else
    png_set_strip_16(png_ptr);
+#endif
 
    /* Strip alpha bytes from the input data without combining with the
     * background (not recommended).

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "April 3, 2011"
+.TH LIBPNGPF 3 "September 26, 2011"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.5.3beta02
+libpng \- Portable Network Graphics (PNG) Reference Library 1.5.6beta02
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
@@ -18,11 +18,9 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.3beta02
 \fI\fB
 
 .SH DESCRIPTION
-The functions previously listed here are  used privately by libpng
+The functions previously listed here are used privately by libpng
 and are not recommended for use by applications.  They are
-not "exported" to applications using shared libraries.  They
-are listed alphabetically here as an aid to libpng maintainers.
-See pngpriv.h for more information on these functions.
+not "exported" to applications using shared libraries.
 
 .SH SEE ALSO
 .BR "png"(5), " libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "April 3, 2011"
+.TH PNG 5 "September 26, 2011"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION

png.h

@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.5.3beta02 - April 3, 2011
+ * libpng version 1.5.6beta02 - September 26, 2011
  * Copyright (c) 1998-2011 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.)
@@ -11,7 +11,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.5.3beta02 - April 3, 2011: Glenn
+ *   libpng versions 0.97, January 1998, through 1.5.6beta02 - September 26, 2011: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -150,7 +150,17 @@
  *    1.5.2beta01-03          15    10502  15.so.15.2[.0]
  *    1.5.2rc01-03            15    10502  15.so.15.2[.0]
  *    1.5.2                   15    10502  15.so.15.2[.0]
- *    1.5.3beta01-02          15    10503  15.so.15.3[.0]
+ *    1.5.3beta01-10          15    10503  15.so.15.3[.0]
+ *    1.5.3rc01-02            15    10503  15.so.15.3[.0]
+ *    1.5.3beta11             15    10503  15.so.15.3[.0]
+ *    1.5.3 [omitted]
+ *    1.5.4beta01-08          15    10504  15.so.15.4[.0]
+ *    1.5.4rc01               15    10504  15.so.15.4[.0]
+ *    1.5.4                   15    10504  15.so.15.4[.0]
+ *    1.5.5beta01-08          15    10505  15.so.15.5[.0]
+ *    1.5.5rc01               15    10505  15.so.15.5[.0]
+ *    1.5.5                   15    10505  15.so.15.5[.0]
+ *    1.5.6beta01-02          15    10506  15.so.15.6[.0]
  *
  *   Henceforth the source version will match the shared-library major
  *   and minor numbers; the shared-library major version number will be
@@ -182,7 +192,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.5.3beta02, April 3, 2011, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.5.6beta02, September 26, 2011, are
  * Copyright (c) 2004, 2006-2011 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:
@@ -294,25 +304,24 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    April 3, 2011
+ *    September 26, 2011
  *
  *    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 1.5.3beta02 are Y2K compliant.  It is my belief that
+ *    upward through 1.5.6beta02 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
+ *    Libpng only has two year fields.  One is a 2-byte unsigned integer
+ *    that will hold years up to 65535.  The other 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
+ *        "png_char time_buffer" in png_struct
  *
  *    There are seven time-related functions:
  *        png.c: png_convert_to_rfc_1123() in png.c
@@ -356,9 +365,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.5.3beta02"
+#define PNG_LIBPNG_VER_STRING "1.5.6beta02"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.5.3beta02 - April 3, 2011\n"
+     " libpng version 1.5.6beta02 - September 26, 2011\n"
 
 #define PNG_LIBPNG_VER_SONUM   15
 #define PNG_LIBPNG_VER_DLLNUM  15
@@ -366,7 +375,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   5
-#define PNG_LIBPNG_VER_RELEASE 3
+#define PNG_LIBPNG_VER_RELEASE 6
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
@@ -396,7 +405,7 @@
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
-#define PNG_LIBPNG_VER 10503 /* 1.5.3 */
+#define PNG_LIBPNG_VER 10506 /* 1.5.6 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -518,7 +527,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_5_3beta02;
+typedef char* png_libpng_version_1_5_6beta02;
 
 /* Three color definitions.  The order of the red, green, and blue, (and the
  * exact size) is not important, although the size of the fields need to
@@ -595,7 +604,7 @@ typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
  * and whether that contents is compressed or not.  The "key" field
  * points to a regular zero-terminated C string.  The "text", "lang", and
  * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
- * However, the * structure returned by png_get_text() will always contain
+ * However, the structure returned by png_get_text() will always contain
  * regular zero-terminated C strings (possibly empty), never NULL pointers,
  * so they can be safely used in printf() and other string-handling functions.
  */
@@ -666,12 +675,24 @@ typedef struct png_unknown_chunk_t
     /* libpng-using applications should NOT directly modify this byte. */
     png_byte location; /* mode of operation at read time */
 }
+
+
 png_unknown_chunk;
 typedef png_unknown_chunk FAR * png_unknown_chunkp;
 typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp;
 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
 #endif
 
+/* Values for the unknown chunk location byte */
+
+#define PNG_HAVE_IHDR  0x01
+#define PNG_HAVE_PLTE  0x02
+#define PNG_AFTER_IDAT 0x08
+
+/* The complete definition of png_info has, as of libpng-1.5.0,
+ * been moved into a separate header file that is not accessible to
+ * applications.  Read libpng-manual.txt or libpng.3 for more info.
+ */
 typedef struct png_info_def png_info;
 typedef png_info FAR * png_infop;
 typedef PNG_CONST png_info FAR * png_const_infop;
@@ -687,6 +708,8 @@ typedef png_info FAR * FAR * png_infopp;
  */
 #define PNG_FP_1    100000
 #define PNG_FP_HALF  50000
+#define PNG_FP_MAX  ((png_fixed_point)0x7fffffffL)
+#define PNG_FP_MIN  (-PNG_FP_MAX)
 
 /* These describe the color_type field in png_info. */
 /* color type masks */
@@ -774,7 +797,7 @@ typedef png_info FAR * FAR * png_infopp;
 #define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
 #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
 #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
-#define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
+#define PNG_INFO_IDAT 0x8000   /* ESR, 1.0.6 */
 
 /* This is used for the transformation routines, as some of them
  * change these values for the row.  It also should enable using
@@ -793,6 +816,14 @@ typedef struct png_row_info_struct
 typedef png_row_info FAR * png_row_infop;
 typedef png_row_info FAR * FAR * png_row_infopp;
 
+/* The complete definition of png_struct has, as of libpng-1.5.0,
+ * been moved into a separate header file that is not accessible to
+ * applications.  Read libpng-manual.txt or libpng.3 for more info.
+ */
+typedef struct png_struct_def png_struct;
+typedef PNG_CONST png_struct FAR * png_const_structp;
+typedef png_struct FAR * png_structp;
+
 /* These are the function types for the I/O functions and for the functions
  * that allow the user to override the default I/O functions with his or her
  * own.  The png_error_ptr type should match that of user-supplied warning
@@ -801,10 +832,6 @@ typedef png_row_info FAR * FAR * png_row_infopp;
  * modify the buffer it is passed. The 'read' function, on the other hand, is
  * expected to return the read data in the buffer.
  */
-typedef struct png_struct_def png_struct;
-typedef PNG_CONST png_struct FAR * png_const_structp;
-typedef png_struct FAR * png_structp;
-
 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
@@ -846,25 +873,18 @@ typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp));
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
-/* This must match the function definition in <setjmp.h>, and the
- * application must include this before png.h to obtain the definition
- * of jmp_buf.  The function is required to be PNG_NORETURN.  (Note that
- * PNG_PTR_NORETURN is used here because current versions of the Microsoft
- * C compiler do not support the PNG_NORETURN attribute on a pointer.)
+/* This must match the function definition in <setjmp.h>, and the application
+ * must include this before png.h to obtain the definition of jmp_buf.  The
+ * function is required to be PNG_NORETURN, but this is not checked.  If the
+ * function does return the application will crash via an abort() or similar
+ * system level call.
  *
- * If you get a type warning from the compiler when linking against this line
- * then your compiler has 'longjmp' that does not match the requirements of the
- * compiler that built libpng.  You will have to write a wrapper function for
- * your compiler's longjmp and call png_set_longjmp_fn directly (not via the
- * png_jmpbuf macro.)
- *
- * If you get a warning here while building the library you will need to make
+ * If you get a warning here while building the library you may need to make
  * changes to ensure that pnglibconf.h records the calling convention used by
  * your compiler.  This may be very difficult - try using a different compiler
  * to build the library!
  */
-typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)),
-   PNG_PTR_NORETURN);
+PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
 #endif
 
 /* Transform masks for the high-level interface */
@@ -886,6 +906,9 @@ typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)),
 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
 /* Added to libpng-1.4.0 */
 #define PNG_TRANSFORM_GRAY_TO_RGB   0x2000      /* read only */
+/* Added to libpng-1.5.4 */
+#define PNG_TRANSFORM_EXPAND_16     0x4000      /* read only */
+#define PNG_TRANSFORM_SCALE_16      0x8000      /* read only */
 
 /* Flags for MNG supported features */
 #define PNG_FLAG_MNG_EMPTY_PLTE     0x01
@@ -1080,7 +1103,7 @@ PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_EXPAND_16_SUPPORTED
-/* Expand to 16 bit channels, forces conversion of palette to RGB and expansion
+/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
  * of a tRNS chunk if present.
  */
 PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr));
@@ -1107,8 +1130,219 @@ PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp
     png_ptr));
 #endif
 
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
     png_colorp palette));
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* How the alpha channel is interpreted - this affects how the color channels of
+ * a PNG file are returned when an alpha channel, or tRNS chunk in a palette
+ * file, is present.
+ *
+ * This has no effect on the way pixels are written into a PNG output
+ * datastream. The color samples in a PNG datastream are never premultiplied
+ * with the alpha samples.
+ *
+ * The default is to return data according to the PNG specification: the alpha
+ * channel is a linear measure of the contribution of the pixel to the
+ * corresponding composited pixel.  The gamma encoded color channels must be
+ * scaled according to the contribution and to do this it is necessary to undo
+ * the encoding, scale the color values, perform the composition and reencode
+ * the values.  This is the 'PNG' mode.
+ *
+ * The alternative is to 'associate' the alpha with the color information by
+ * storing color channel values that have been scaled by the alpha.  The
+ * advantage is that the color channels can be resampled (the image can be
+ * scaled) in this form.  The disadvantage is that normal practice is to store
+ * linear, not (gamma) encoded, values and this requires 16-bit channels for
+ * still images rather than the 8-bit channels that are just about sufficient if
+ * gamma encoding is used.  In addition all non-transparent pixel values,
+ * including completely opaque ones, must be gamma encoded to produce the final
+ * image.  This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the
+ * latter being the two common names for associated alpha color channels.)
+ *
+ * Since it is not necessary to perform arithmetic on opaque color values so
+ * long as they are not to be resampled and are in the final color space it is
+ * possible to optimize the handling of alpha by storing the opaque pixels in
+ * the PNG format (adjusted for the output color space) while storing partially
+ * opaque pixels in the standard, linear, format.  The accuracy required for
+ * standard alpha composition is relatively low, because the pixels are
+ * isolated, therefore typically the accuracy loss in storing 8-bit linear
+ * values is acceptable.  (This is not true if the alpha channel is used to
+ * simulate transparency over large areas - use 16 bits or the PNG mode in
+ * this case!)  This is the 'OPTIMIZED' mode.  For this mode a pixel is
+ * treated as opaque only if the alpha value is equal to the maximum value.
+ *
+ * The final choice is to gamma encode the alpha channel as well.  This is
+ * broken because, in practice, no implementation that uses this choice
+ * correctly undoes the encoding before handling alpha composition.  Use this
+ * choice only if other serious errors in the software or hardware you use
+ * mandate it; the typical serious error is for dark halos to appear around
+ * opaque areas of the composited PNG image because of arithmetic overflow.
+ *
+ * The API function png_set_alpha_mode specifies which of these choices to use
+ * with an enumerated 'mode' value and the gamma of the required output:
+ */
+#define PNG_ALPHA_PNG           0 /* according to the PNG standard */
+#define PNG_ALPHA_STANDARD      1 /* according to Porter/Duff */
+#define PNG_ALPHA_ASSOCIATED    1 /* as above; this is the normal practice */
+#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
+#define PNG_ALPHA_OPTIMIZED     2 /* 'PNG' for opaque pixels, else 'STANDARD' */
+#define PNG_ALPHA_BROKEN        3 /* the alpha channel is gamma encoded */
+
+PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structp png_ptr, int mode,
+    double output_gamma));
+PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structp png_ptr,
+    int mode, png_fixed_point output_gamma));
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+/* The output_gamma value is a screen gamma in libpng terminology: it expresses
+ * how to decode the output values, not how they are encoded.  The values used
+ * correspond to the normal numbers used to describe the overall gamma of a
+ * computer display system; for example 2.2 for an sRGB conformant system.  The
+ * values are scaled by 100000 in the _fixed version of the API (so 220000 for
+ * sRGB.)
+ *
+ * The inverse of the value is always used to provide a default for the PNG file
+ * encoding if it has no gAMA chunk and if png_set_gamma() has not been called
+ * to override the PNG gamma information.
+ *
+ * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
+ * opaque pixels however pixels with lower alpha values are not encoded,
+ * regardless of the output gamma setting.
+ *
+ * When the standard Porter Duff handling is requested with mode 1 the output
+ * encoding is set to be linear and the output_gamma value is only relevant
+ * as a default for input data that has no gamma information.  The linear output
+ * encoding will be overridden if png_set_gamma() is called - the results may be
+ * highly unexpected!
+ *
+ * The following numbers are derived from the sRGB standard and the research
+ * behind it.  sRGB is defined to be approximated by a PNG gAMA chunk value of
+ * 0.45455 (1/2.2) for PNG.  The value implicitly includes any viewing
+ * correction required to take account of any differences in the color
+ * environment of the original scene and the intended display environment; the
+ * value expresses how to *decode* the image for display, not how the original
+ * data was *encoded*.
+ *
+ * sRGB provides a peg for the PNG standard by defining a viewing environment.
+ * sRGB itself, and earlier TV standards, actually use a more complex transform
+ * (a linear portion then a gamma 2.4 power law) than PNG can express.  (PNG is
+ * limited to simple power laws.)  By saying that an image for direct display on
+ * an sRGB conformant system should be stored with a gAMA chunk value of 45455
+ * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
+ * makes it possible to derive values for other display systems and
+ * environments.
+ *
+ * The Mac value is deduced from the sRGB based on an assumption that the actual
+ * extra viewing correction used in early Mac display systems was implemented as
+ * a power 1.45 lookup table.
+ *
+ * Any system where a programmable lookup table is used or where the behavior of
+ * the final display device characteristics can be changed requires system
+ * specific code to obtain the current characteristic.  However this can be
+ * difficult and most PNG gamma correction only requires an approximate value.
+ *
+ * By default, if png_set_alpha_mode() is not called, libpng assumes that all
+ * values are unencoded, linear, values and that the output device also has a
+ * linear characteristic.  This is only very rarely correct - it is invariably
+ * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
+ * default if you don't know what the right answer is!
+ *
+ * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
+ * 10.6) which used a correction table to implement a somewhat lower gamma on an
+ * otherwise sRGB system.
+ *
+ * Both these values are reserved (not simple gamma values) in order to allow
+ * more precise correction internally in the future.
+ *
+ * NOTE: the following values can be passed to either the fixed or floating
+ * point APIs, but the floating point API will also accept floating point
+ * values.
+ */
+#define PNG_DEFAULT_sRGB -1       /* sRGB gamma and color space */
+#define PNG_GAMMA_MAC_18 -2       /* Old Mac '1.8' gamma and color space */
+#define PNG_GAMMA_sRGB   220000   /* Television standards--matches sRGB gamma */
+#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
+#endif
+
+/* The following are examples of calls to png_set_alpha_mode to achieve the
+ * required overall gamma correction and, where necessary, alpha
+ * premultiplication.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ *    This is the default libpng handling of the alpha channel - it is not
+ *    pre-multiplied into the color components.  In addition the call states
+ *    that the output is for a sRGB system and causes all PNG files without gAMA
+ *    chunks to be assumed to be encoded using sRGB.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ *    In this case the output is assumed to be something like an sRGB conformant
+ *    display preceeded by a power-law lookup table of power 1.45.  This is how
+ *    early Mac systems behaved.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
+ *    This is the classic Jim Blinn approach and will work in academic
+ *    environments where everything is done by the book.  It has the shortcoming
+ *    of assuming that input PNG data with no gamma information is linear - this
+ *    is unlikely to be correct unless the PNG files where generated locally.
+ *    Most of the time the output precision will be so low as to show
+ *    significant banding in dark areas of the image.
+ *
+ * png_set_expand_16(pp);
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
+ *    This is a somewhat more realistic Jim Blinn inspired approach.  PNG files
+ *    are assumed to have the sRGB encoding if not marked with a gamma value and
+ *    the output is always 16 bits per component.  This permits accurate scaling
+ *    and processing of the data.  If you know that your input PNG files were
+ *    generated locally you might need to replace PNG_DEFAULT_sRGB with the
+ *    correct value for your system.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
+ *    If you just need to composite the PNG image onto an existing background
+ *    and if you control the code that does this you can use the optimization
+ *    setting.  In this case you just copy completely opaque pixels to the
+ *    output.  For pixels that are not completely transparent (you just skip
+ *    those) you do the composition math using png_composite or png_composite_16
+ *    below then encode the resultant 8-bit or 16-bit values to match the output
+ *    encoding.
+ *
+ * Other cases
+ *    If neither the PNG nor the standard linear encoding work for you because
+ *    of the software or hardware you use then you have a big problem.  The PNG
+ *    case will probably result in halos around the image.  The linear encoding
+ *    will probably result in a washed out, too bright, image (it's actually too
+ *    contrasty.)  Try the ALPHA_OPTIMIZED mode above - this will probably
+ *    substantially reduce the halos.  Alternatively try:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
+ *    This option will also reduce the halos, but there will be slight dark
+ *    halos round the opaque parts of the image where the background is light.
+ *    In the OPTIMIZED mode the halos will be light halos where the background
+ *    is dark.  Take your pick - the halos are unavoidable unless you can get
+ *    your hardware/software fixed!  (The OPTIMIZED approach is slightly
+ *    faster.)
+ *
+ * When the default gamma of PNG files doesn't match the output gamma.
+ *    If you have PNG files with no gamma information png_set_alpha_mode allows
+ *    you to provide a default gamma, but it also sets the ouput gamma to the
+ *    matching value.  If you know your PNG files have a gamma that doesn't
+ *    match the output you can take advantage of the fact that
+ *    png_set_alpha_mode always sets the output gamma but only sets the PNG
+ *    default if it is not already set:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ *    The first call sets both the default and the output gamma values, the
+ *    second call overrides the output gamma without changing the default.  This
+ *    is easier than achieving the same effect with png_set_gamma.  You must use
+ *    PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
+ *    fire if more than one call to png_set_alpha_mode and png_set_background is
+ *    made in the same read operation, however multiple calls with PNG_ALPHA_PNG
+ *    are ignored.
+ */
 
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr));
@@ -1176,7 +1410,11 @@ PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
-/* Handle alpha and tRNS by replacing with a background color. */
+/* Handle alpha and tRNS by replacing with a background color.  Prior to
+ * libpng-1.5.4 this API must not be called before the PNG file header has been
+ * read.  Doing so will result in unexpected behavior and possible warnings or
+ * errors if the PNG file contains a bKGD chunk.
+ */
 PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr,
     png_const_color_16p background_color, int background_gamma_code,
     int need_expand, double background_gamma));
@@ -1191,7 +1429,13 @@ PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr,
 #  define PNG_BACKGROUND_GAMMA_UNIQUE  3
 #endif
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale a 16-bit depth file down to 8-bit, accurately. */
+PNG_EXPORT(229, void, png_set_scale_16, (png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */
 /* Strip the second byte of information from a 16-bit depth file. */
 PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr));
 #endif
@@ -1212,12 +1456,22 @@ PNG_EXPORT(49, void, png_set_quantize,
  */
 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
 
-/* Handle gamma correction. Screen_gamma=(display_exponent) */
+/* Handle gamma correction. Screen_gamma=(display_exponent).
+ * NOTE: this API simply sets the screen and file gamma values. It will
+ * therefore override the value for gamma in a PNG file if it is called after
+ * the file header has been read - use with care  - call before reading the PNG
+ * file for best results!
+ *
+ * These routines accept the same gamma values as png_set_alpha_mode (described
+ * above).  The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
+ * API (floating point or fixed.)  Notice, however, that the 'file_gamma' value
+ * is the inverse of a 'screen gamma' value.
+ */
 PNG_FP_EXPORT(50, void, png_set_gamma,
     (png_structp png_ptr, double screen_gamma,
-    double default_file_gamma));
+    double override_file_gamma));
 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr,
-    png_fixed_point screen_gamma, png_fixed_point default_file_gamma));
+    png_fixed_point screen_gamma, png_fixed_point override_file_gamma));
 #endif
 
 #ifdef PNG_WRITE_FLUSH_SUPPORTED
@@ -1392,6 +1646,7 @@ PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
 #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
 #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
 
+#ifdef PNG_WRITE_SUPPORTED
 /* Set the library compression level.  Currently, valid values range from
  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
@@ -1408,13 +1663,17 @@ PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr,
 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr,
     int strategy));
 
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr,
     int window_bits));
 
 PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr,
     int method));
+#endif
 
-#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 /* Also set zlib parameters for compressing non-IDAT chunks */
 PNG_EXPORT(222, void, png_set_text_compression_level,
     (png_structp png_ptr, int level));
@@ -1425,12 +1684,15 @@ PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structp png_ptr,
 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structp png_ptr,
     int strategy));
 
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
 PNG_EXPORT(225, void, png_set_text_compression_window_bits, (png_structp
     png_ptr, int window_bits));
 
 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structp png_ptr,
     int method));
-#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
+#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
 
 /* These next functions are called for input/output, memory, and error
  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
@@ -1642,6 +1904,7 @@ PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr,
 PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN);
 #endif
 
+#ifdef PNG_WARNINGS_SUPPORTED
 /* Non-fatal error in libpng.  Can continue, but may have a problem. */
 PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
     png_const_charp warning_message));
@@ -1649,6 +1912,7 @@ PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
 /* Non-fatal error in libpng, chunk name is prepended to message. */
 PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr,
     png_const_charp warning_message));
+#endif
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 /* Benign error in libpng.  Can continue, but may have a problem.
@@ -1787,6 +2051,10 @@ PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr,
    png_const_infop info_ptr, double *white_x, double *white_y, double *red_x,
     double *red_y, double *green_x, double *green_y, double *blue_x,
     double *blue_y));
+PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_structp png_ptr,
+    png_const_infop info_ptr, double *red_X, double *red_Y, double *red_Z,
+    double *green_X, double *green_Y, double *green_Z, double *blue_X,
+    double *blue_Y, double *blue_Z));
 #ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */
 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
     (png_const_structp png_ptr,
@@ -1796,6 +2064,13 @@ PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
     png_fixed_point *int_green_y, png_fixed_point *int_blue_x,
     png_fixed_point *int_blue_y));
 #endif
+PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
+    (png_structp png_ptr, png_const_infop info_ptr,
+    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+    png_fixed_point *int_blue_Z));
 #endif
 
 #ifdef PNG_cHRM_SUPPORTED
@@ -1803,12 +2078,22 @@ PNG_FP_EXPORT(135, void, png_set_cHRM,
     (png_structp png_ptr, png_infop info_ptr,
     double white_x, double white_y, double red_x, double red_y, double green_x,
     double green_y, double blue_x, double blue_y));
+PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_structp png_ptr,
+    png_infop info_ptr, double red_X, double red_Y, double red_Z,
+    double green_X, double green_Y, double green_Z, double blue_X,
+    double blue_Y, double blue_Z));
 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr,
     png_infop info_ptr, png_fixed_point int_white_x,
     png_fixed_point int_white_y, png_fixed_point int_red_x,
     png_fixed_point int_red_y, png_fixed_point int_green_x,
     png_fixed_point int_green_y, png_fixed_point int_blue_x,
     png_fixed_point int_blue_y));
+PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_structp png_ptr,
+    png_infop info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
+    png_fixed_point int_red_Z, png_fixed_point int_green_X,
+    png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+    png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+    png_fixed_point int_blue_Z));
 #endif
 
 #ifdef PNG_gAMA_SUPPORTED
@@ -2021,15 +2306,21 @@ PNG_EXPORT(171, void, png_set_sCAL_s,
 /* Provide a list of chunks and how they are to be handled, if the built-in
    handling or default unknown chunk handling is not desired.  Any chunks not
    listed will be handled in the default manner.  The IHDR and IEND chunks
-   must not be listed.
-      keep = 0: follow default behaviour
-           = 1: do not keep
-           = 2: keep only if safe-to-copy
-           = 3: keep even if unsafe-to-copy
+   must not be listed.  Because this turns off the default handling for chunks
+   that would otherwise be recognized the behavior of libpng transformations may
+   well become incorrect!
+      keep = 0: PNG_HANDLE_CHUNK_AS_DEFAULT: follow default behavior
+           = 1: PNG_HANDLE_CHUNK_NEVER:      do not keep
+           = 2: PNG_HANDLE_CHUNK_IF_SAFE:    keep only if safe-to-copy
+           = 3: PNG_HANDLE_CHUNK_ALWAYS:     keep even if unsafe-to-copy
 */
 PNG_EXPORT(172, void, png_set_keep_unknown_chunks,
     (png_structp png_ptr, int keep,
     png_const_bytep chunk_list, int num_chunks));
+
+/* The handling code is returned; the result is therefore true (non-zero) if
+ * special handling is required, false for the default handling.
+ */
 PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr,
     png_const_bytep chunk_name));
 #endif
@@ -2232,14 +2523,14 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
      { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
            * (png_uint_16)(alpha)                         \
            + (png_uint_16)(bg)*(png_uint_16)(255          \
-           - (png_uint_16)(alpha)) + (png_uint_16)128);   \
+           - (png_uint_16)(alpha)) + 128);                \
        (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
 
 #  define png_composite_16(composite, fg, alpha, bg)       \
      { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg)  \
            * (png_uint_32)(alpha)                          \
-           + (png_uint_32)(bg)*(png_uint_32)(65535L        \
-           - (png_uint_32)(alpha)) + (png_uint_32)32768L); \
+           + (png_uint_32)(bg)*(65535                      \
+           - (png_uint_32)(alpha)) + 32768);               \
        (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
 
 #else  /* Standard method using integer division */
@@ -2247,12 +2538,12 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
 #  define png_composite(composite, fg, alpha, bg)                          \
      (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +  \
      (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
-     (png_uint_16)127) / 255)
+     127) / 255)
 
 #  define png_composite_16(composite, fg, alpha, bg)                         \
      (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
-     (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +        \
-     (png_uint_32)32767) / (png_uint_32)65535L)
+     (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) +         \
+     32767) / 65535)
 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
 
 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
@@ -2316,7 +2607,7 @@ PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
  * scripts/symbols.def as well.
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
-  PNG_EXPORT_LAST_ORDINAL(226);
+  PNG_EXPORT_LAST_ORDINAL(233);
 #endif
 
 #ifdef __cplusplus

pngconf.h

@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.5.3beta02 - March 31, 2011
+ * libpng version 1.5.6beta02 - September 26, 2011
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -164,7 +164,9 @@
  *                       'type', compiler specific.
  *
  * PNG_DLL_EXPORT Set to the magic to use during a libpng build to
- *                make a symbol exported from the DLL.
+ *                make a symbol exported from the DLL.  Not used in the
+ *                public header files; see pngpriv.h for how it is used
+ *                in the libpng build.
  *
  * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come
  *                from a DLL - used to define PNG_IMPEXP when
@@ -258,25 +260,14 @@
 #  define PNGAPI PNGCAPI
 #endif
 
-/* The default for PNG_IMPEXP depends on whether the library is
- * being built or used.
+/* PNG_IMPEXP may be set on the compilation system command line or (if not set)
+ * then in an internal header file when building the library, otherwise (when
+ * using the library) it is set here.
  */
 #ifndef PNG_IMPEXP
-#  ifdef PNGLIB_BUILD
-    /* Building the library */
-#    if (defined(DLL_EXPORT)/*from libtool*/ ||\
-        defined(_WINDLL) || defined(_DLL) || defined(__DLL__) ||\
-        defined(_USRDLL) ||\
-        defined(PNG_BUILD_DLL)) && defined(PNG_DLL_EXPORT)
-      /* Building a DLL. */
-#      define PNG_IMPEXP PNG_DLL_EXPORT
-#    endif /* DLL */
-#  else
-    /* Using the library */
-#    if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
-      /* This forces use of a DLL, disallowing static linking */
-#      define PNG_IMPEXP PNG_DLL_IMPORT
-#    endif
+#  if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
+     /* This forces use of a DLL, disallowing static linking */
+#    define PNG_IMPEXP PNG_DLL_IMPORT
 #  endif
 
 #  ifndef PNG_IMPEXP
@@ -353,48 +344,21 @@
 #    ifndef PNG_NORETURN
 #      define PNG_NORETURN   __attribute__((__noreturn__))
 #    endif
-#    ifndef PNG_PTR_NORETURN
-       /* It's not enough to have the compiler be the correct compiler at
-        * this point - it's necessary for the library (which defines
-        * the type of the library longjmp) to also be the GNU library.
-        * This is because many systems use the GNU compiler with a
-        * non-GNU libc implementation.  Min/GW headers are also compatible
-        * with GCC as well as uclibc, so it seems best to exclude known
-        * problem libcs here rather than just including known libcs.
-        *
-        * NOTE: this relies on the only use of PNG_PTR_NORETURN being with
-        * the system longjmp.  If the same type is used elsewhere then this
-        * will need to be changed.
-        */
-#      if !defined(__CYGWIN__)
-#         define PNG_PTR_NORETURN   __attribute__((__noreturn__))
-#      endif
-#    endif
 #    ifndef PNG_ALLOCATED
 #      define PNG_ALLOCATED  __attribute__((__malloc__))
 #    endif
-
-    /* This specifically protects structure members that should only be
-     * accessed from within the library, therefore should be empty during
-     * a library build.
-     */
-#    ifndef PNGLIB_BUILD
-#      ifndef PNG_DEPRECATED
-#        define PNG_DEPRECATED __attribute__((__deprecated__))
+#    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
-#      ifndef PNG_DEPSTRUCT
-#        define PNG_DEPSTRUCT  __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
-#    endif /* PNGLIB_BUILD */
+#    endif
 #  endif /* __GNUC__ */
 
 #  if defined(_MSC_VER)  && (_MSC_VER >= 1300)
@@ -404,28 +368,17 @@
 #    ifndef PNG_NORETURN
 #      define PNG_NORETURN   __declspec(noreturn)
 #    endif
-#    ifndef PNG_PTR_NORETURN
-#      define PNG_PTR_NORETURN /* not supported */
-#    endif
 #    ifndef PNG_ALLOCATED
-#      define PNG_ALLOCATED __declspec(restrict)
+#      if defined(_MSC_VER)  && (_MSC_VER >= 1300)
+#        define PNG_ALLOCATED __declspec(restrict)
+#      endif
+#    endif
+#    ifndef PNG_DEPRECATED
+#      define PNG_DEPRECATED __declspec(deprecated)
+#    endif
+#    ifndef PNG_PRIVATE
+#      define PNG_PRIVATE __declspec(deprecated)
 #    endif
-
-    /* This specifically protects structure members that should only be
-     * accessed from within the library, therefore should be empty during
-     * a library build.
-     */
-#    ifndef PNGLIB_BUILD
-#      ifndef PNG_DEPRECATED
-#        define PNG_DEPRECATED __declspec(deprecated)
-#      endif
-#      ifndef PNG_DEPSTRUCT
-#        define PNG_DEPSTRUCT  __declspec(deprecated)
-#      endif
-#      ifndef PNG_PRIVATE
-#        define PNG_PRIVATE __declspec(deprecated)
-#      endif
-#    endif /* PNGLIB_BUILD */
 #  endif /* _MSC_VER */
 #endif /* PNG_PEDANTIC_WARNINGS */
 
@@ -438,15 +391,9 @@
 #ifndef PNG_NORETURN
 #  define PNG_NORETURN    /* This function does not return */
 #endif
-#ifndef PNG_PTR_NORETURN
-#  define PNG_PTR_NORETURN /* This function does not return */
-#endif
 #ifndef PNG_ALLOCATED
 #  define PNG_ALLOCATED   /* The result of the function is new memory */
 #endif
-#ifndef PNG_DEPSTRUCT
-#  define PNG_DEPSTRUCT   /* Access to this struct member is deprecated */
-#endif
 #ifndef PNG_PRIVATE
 #  define PNG_PRIVATE     /* This is a private libpng function */
 #endif

pngerror.c

@@ -1,7 +1,7 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Last changed in libpng 1.5.6 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 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.)
@@ -89,15 +89,121 @@ png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN)
 PNG_FUNCTION(void,PNGAPI
 png_err,(png_structp png_ptr),PNG_NORETURN)
 {
+   /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
+    * erroneously as '\0', instead of the empty string "".  This was
+    * apparently an error, introduced in libpng-1.2.20, and png_default_error
+    * will crash in this case.
+    */
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_ptr, '\0');
+      (*(png_ptr->error_fn))(png_ptr, "");
 
    /* If the custom handler doesn't exist, or if it returns,
       use the default handler, which will not return. */
-   png_default_error(png_ptr, '\0');
+   png_default_error(png_ptr, "");
 }
 #endif /* PNG_ERROR_TEXT_SUPPORTED */
 
+/* Utility to safely appends strings to a buffer.  This never errors out so
+ * error checking is not required in the caller.
+ */
+size_t
+png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+   png_const_charp string)
+{
+   if (buffer != NULL && pos < bufsize)
+   {
+      if (string != NULL)
+         while (*string != '\0' && pos < bufsize-1)
+           buffer[pos++] = *string++;
+
+      buffer[pos] = '\0';
+   }
+
+   return pos;
+}
+
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.
+ */
+png_charp
+png_format_number(png_const_charp start, png_charp end, int format,
+   png_alloc_size_t number)
+{
+   int count = 0;    /* number of digits output */
+   int mincount = 1; /* minimum number required */
+   int output = 0;   /* digit output (for the fixed point format) */
+
+   *--end = '\0';
+
+   /* This is written so that the loop always runs at least once, even with
+    * number zero.
+    */
+   while (end > start && (number != 0 || count < mincount))
+   {
+
+      static const char digits[] = "0123456789ABCDEF";
+
+      switch (format)
+      {
+         case PNG_NUMBER_FORMAT_fixed:
+            /* Needs five digits (the fraction) */
+            mincount = 5;
+            if (output || number % 10 != 0)
+            {
+               *--end = digits[number % 10];
+               output = 1;
+            }
+            number /= 10;
+            break;
+
+         case PNG_NUMBER_FORMAT_02u:
+            /* Expects at least 2 digits. */
+            mincount = 2;
+            /* fall through */
+
+         case PNG_NUMBER_FORMAT_u:
+            *--end = digits[number % 10];
+            number /= 10;
+            break;
+
+         case PNG_NUMBER_FORMAT_02x:
+            /* This format expects at least two digits */
+            mincount = 2;
+            /* fall through */
+
+         case PNG_NUMBER_FORMAT_x:
+            *--end = digits[number & 0xf];
+            number >>= 4;
+            break;
+
+         default: /* an error */
+            number = 0;
+            break;
+      }
+
+      /* Keep track of the number of digits added */
+      ++count;
+
+      /* Float a fixed number here: */
+      if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
+      {
+         /* End of the fraction, but maybe nothing was output?  In that case
+          * drop the decimal point.  If the number is a true zero handle that
+          * here.
+          */
+         if (output)
+            *--end = '.';
+         else if (number == 0) /* and !output */
+            *--end = '0';
+      }
+   }
+
+   return end;
+}
+#endif
+
 #ifdef PNG_WARNINGS_SUPPORTED
 /* This function is called whenever there is a non-fatal error.  This function
  * should not be changed.  If there is a need to handle warnings differently,
@@ -128,6 +234,115 @@ png_warning(png_structp png_ptr, png_const_charp warning_message)
    else
       png_default_warning(png_ptr, warning_message + offset);
 }
+
+/* These functions support 'formatted' warning messages with up to
+ * PNG_WARNING_PARAMETER_COUNT parameters.  In the format string the parameter
+ * is introduced by @<number>, where 'number' starts at 1.  This follows the
+ * standard established by X/Open for internationalizable error messages.
+ */
+void
+png_warning_parameter(png_warning_parameters p, int number,
+   png_const_charp string)
+{
+   if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
+      (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
+}
+
+void
+png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
+   png_alloc_size_t value)
+{
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+   png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
+}
+
+void
+png_warning_parameter_signed(png_warning_parameters p, int number, int format,
+   png_int_32 value)
+{
+   png_alloc_size_t u;
+   png_charp str;
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+
+   /* Avoid overflow by doing the negate in a png_alloc_size_t: */
+   u = (png_alloc_size_t)value;
+   if (value < 0)
+      u = ~u + 1;
+
+   str = PNG_FORMAT_NUMBER(buffer, format, u);
+
+   if (value < 0 && str > buffer)
+      *--str = '-';
+
+   png_warning_parameter(p, number, str);
+}
+
+void
+png_formatted_warning(png_structp png_ptr, png_warning_parameters p,
+   png_const_charp message)
+{
+   /* The internal buffer is just 128 bytes - enough for all our messages,
+    * overflow doesn't happen because this code checks!
+    */
+   size_t i;
+   char msg[128];
+
+   for (i=0; i<(sizeof msg)-1 && *message != '\0'; ++i)
+   {
+      if (*message == '@')
+      {
+         int parameter = -1;
+         switch (*++message)
+         {
+            case '1':
+               parameter = 0;
+               break;
+
+            case '2':
+               parameter = 1;
+               break;
+
+            case '\0':
+               continue; /* To break out of the for loop above. */
+
+            default:
+               break;
+         }
+
+         if (parameter >= 0 && parameter < PNG_WARNING_PARAMETER_COUNT)
+         {
+            /* Append this parameter */
+            png_const_charp parm = p[parameter];
+            png_const_charp pend = p[parameter] + (sizeof p[parameter]);
+
+            /* No need to copy the trailing '\0' here, but there is no guarantee
+             * that parm[] has been initialized, so there is no guarantee of a
+             * trailing '\0':
+             */
+            for (; i<(sizeof msg)-1 && parm != '\0' && parm < pend; ++i)
+               msg[i] = *parm++;
+
+            ++message;
+            continue;
+         }
+
+         /* else not a parameter and there is a character after the @ sign; just
+          * copy that.
+          */
+      }
+
+      /* At this point *message can't be '\0', even in the bad parameter case
+       * above where there is a lone '@' at the end of the message string.
+       */
+      msg[i] = *message++;
+   }
+
+   /* i is always less than (sizeof msg), so: */
+   msg[i] = '\0';
+
+   /* And this is the formatted message: */
+   png_warning(png_ptr, msg);
+}
 #endif /* PNG_WARNINGS_SUPPORTED */
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
@@ -159,11 +374,14 @@ static void /* PRIVATE */
 png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
     error_message)
 {
-   int iout = 0, iin = 0;
+   png_uint_32 chunk_name = png_ptr->chunk_name;
+   int iout = 0, ishift = 24;
 
-   while (iin < 4)
+   while (ishift >= 0)
    {
-      int c = png_ptr->chunk_name[iin++];
+      int c = (int)(chunk_name >> ishift) & 0xff;
+
+      ishift -= 8;
       if (isnonalpha(c))
       {
          buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
@@ -174,7 +392,7 @@ png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
 
       else
       {
-         buffer[iout++] = (png_byte)c;
+         buffer[iout++] = (char)c;
       }
    }
 
@@ -183,10 +401,16 @@ png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
 
    else
    {
+      int iin = 0;
+
       buffer[iout++] = ':';
       buffer[iout++] = ' ';
-      png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);
-      buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';
+
+      while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
+         buffer[iout++] = error_message[iin++];
+
+      /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
+      buffer[iout] = '\0';
    }
 }
 #endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
@@ -272,7 +496,7 @@ png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn,
       return NULL;
 
    png_ptr->longjmp_fn = longjmp_fn;
-   return &png_ptr->png_jmpbuf;
+   return &png_ptr->longjmp_buffer;
 }
 #endif
 
@@ -287,7 +511,8 @@ png_default_error,(png_structp png_ptr, png_const_charp error_message),
 {
 #ifdef PNG_CONSOLE_IO_SUPPORTED
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   if (*error_message == PNG_LITERAL_SHARP)
+   /* Check on NULL only added in 1.5.4 */
+   if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
    {
       /* Strip "#nnnn " from beginning of error message. */
       int offset;
@@ -317,11 +542,11 @@ png_default_error,(png_structp png_ptr, png_const_charp error_message),
    else
 #endif
    {
-      fprintf(stderr, "libpng error: %s", error_message);
+      fprintf(stderr, "libpng error: %s", error_message ? error_message :
+         "undefined");
       fprintf(stderr, PNG_STRING_NEWLINE);
    }
-#endif
-#ifndef PNG_CONSOLE_IO_SUPPORTED
+#else
    PNG_UNUSED(error_message) /* Make compiler happy */
 #endif
    png_longjmp(png_ptr, 1);
@@ -335,13 +560,13 @@ png_longjmp,(png_structp png_ptr, int val),PNG_NORETURN)
    {
 #  ifdef USE_FAR_KEYWORD
       {
-         jmp_buf png_jmpbuf;
-         png_memcpy(png_jmpbuf, png_ptr->png_jmpbuf, png_sizeof(jmp_buf));
-         png_ptr->longjmp_fn(png_jmpbuf, val);
+         jmp_buf tmp_jmpbuf;
+         png_memcpy(tmp_jmpbuf, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
+         png_ptr->longjmp_fn(tmp_jmpbuf, val);
       }
 
 #  else
-   png_ptr->longjmp_fn(png_ptr->png_jmpbuf, val);
+   png_ptr->longjmp_fn(png_ptr->longjmp_buffer, val);
 #  endif
    }
 #endif
@@ -403,7 +628,7 @@ png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 /* This function is called when the application wants to use another method
  * of handling errors and warnings.  Note that the error function MUST NOT
  * return to the calling routine or serious problems will occur.  The return
- * method used in the default routine calls longjmp(png_ptr->png_jmpbuf, 1)
+ * method used in the default routine calls longjmp(png_ptr->longjmp_buffer, 1)
  */
 void PNGAPI
 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
@@ -414,7 +639,11 @@ png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 
    png_ptr->error_ptr = error_ptr;
    png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_ptr->warning_fn = warning_fn;
+#else
+   PNG_UNUSED(warning_fn)
+#endif
 }
 
 

pngget.c

@@ -1,7 +1,7 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Last changed in libpng 1.5.6 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 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.)
@@ -459,6 +459,65 @@ png_get_bKGD(png_const_structp png_ptr, png_infop info_ptr,
 #endif
 
 #ifdef PNG_cHRM_SUPPORTED
+/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the
+ * same time to correct the rgb grayscale coefficient defaults obtained from the
+ * cHRM chunk in 1.5.4
+ */
+png_uint_32 PNGFAPI
+png_get_cHRM_XYZ_fixed(png_structp png_ptr, png_const_infop info_ptr,
+    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+    png_fixed_point *int_blue_Z)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   {
+      png_xy xy;
+      png_XYZ XYZ;
+
+      png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
+
+      xy.whitex = info_ptr->x_white;
+      xy.whitey = info_ptr->y_white;
+      xy.redx = info_ptr->x_red;
+      xy.redy = info_ptr->y_red;
+      xy.greenx = info_ptr->x_green;
+      xy.greeny = info_ptr->y_green;
+      xy.bluex = info_ptr->x_blue;
+      xy.bluey = info_ptr->y_blue;
+
+      /* The *_checked function handles error reporting, so just return 0 if
+       * there is a failure here.
+       */
+      if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy))
+      {
+         if (int_red_X != NULL)
+            *int_red_X = XYZ.redX;
+         if (int_red_Y != NULL)
+            *int_red_Y = XYZ.redY;
+         if (int_red_Z != NULL)
+            *int_red_Z = XYZ.redZ;
+         if (int_green_X != NULL)
+            *int_green_X = XYZ.greenX;
+         if (int_green_Y != NULL)
+            *int_green_Y = XYZ.greenY;
+         if (int_green_Z != NULL)
+            *int_green_Z = XYZ.greenZ;
+         if (int_blue_X != NULL)
+            *int_blue_X = XYZ.blueX;
+         if (int_blue_Y != NULL)
+            *int_blue_Y = XYZ.blueY;
+         if (int_blue_Z != NULL)
+            *int_blue_Z = XYZ.blueZ;
+
+         return (PNG_INFO_cHRM);
+      }
+   }
+
+   return (0);
+}
+
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32 PNGAPI
 png_get_cHRM(png_const_structp png_ptr, png_const_infop info_ptr,
@@ -490,6 +549,42 @@ png_get_cHRM(png_const_structp png_ptr, png_const_infop info_ptr,
 
    return (0);
 }
+
+png_uint_32 PNGAPI
+png_get_cHRM_XYZ(png_structp png_ptr, png_const_infop info_ptr,
+   double *red_X, double *red_Y, double *red_Z, double *green_X,
+   double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
+   double *blue_Z)
+{
+   png_XYZ XYZ;
+
+   if (png_get_cHRM_XYZ_fixed(png_ptr, info_ptr,
+      &XYZ.redX, &XYZ.redY, &XYZ.redZ, &XYZ.greenX, &XYZ.greenY, &XYZ.greenZ,
+      &XYZ.blueX, &XYZ.blueY, &XYZ.blueZ) & PNG_INFO_cHRM)
+   {
+      if (red_X != NULL)
+         *red_X = png_float(png_ptr, XYZ.redX, "cHRM red X");
+      if (red_Y != NULL)
+         *red_Y = png_float(png_ptr, XYZ.redY, "cHRM red Y");
+      if (red_Z != NULL)
+         *red_Z = png_float(png_ptr, XYZ.redZ, "cHRM red Z");
+      if (green_X != NULL)
+         *green_X = png_float(png_ptr, XYZ.greenX, "cHRM green X");
+      if (green_Y != NULL)
+         *green_Y = png_float(png_ptr, XYZ.greenY, "cHRM green Y");
+      if (green_Z != NULL)
+         *green_Z = png_float(png_ptr, XYZ.greenZ, "cHRM green Z");
+      if (blue_X != NULL)
+         *blue_X = png_float(png_ptr, XYZ.blueX, "cHRM blue X");
+      if (blue_Y != NULL)
+         *blue_Y = png_float(png_ptr, XYZ.blueY, "cHRM blue Y");
+      if (blue_Z != NULL)
+         *blue_Z = png_float(png_ptr, XYZ.blueZ, "cHRM blue Z");
+      return (PNG_INFO_cHRM);
+   }
+
+   return (0);
+}
 #  endif
 
 #  ifdef PNG_FIXED_POINT_SUPPORTED
@@ -855,9 +950,8 @@ png_get_text(png_const_structp png_ptr, png_const_infop info_ptr,
 {
    if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
    {
-      png_debug1(1, "in %s retrieval function",
-          (png_ptr->chunk_name[0] == '\0' ? "text" :
-          (png_const_charp)png_ptr->chunk_name));
+      png_debug1(1, "in 0x%lx retrieval function",
+         (unsigned long)png_ptr->chunk_name);
 
       if (text_ptr != NULL)
          *text_ptr = info_ptr->text;
@@ -971,7 +1065,7 @@ png_get_user_chunk_ptr(png_const_structp png_ptr)
 png_size_t PNGAPI
 png_get_compression_buffer_size(png_const_structp png_ptr)
 {
-   return (png_ptr ? png_ptr->zbuf_size : 0L);
+   return (png_ptr ? png_ptr->zbuf_size : 0);
 }
 
 
@@ -1016,16 +1110,14 @@ png_get_io_state (png_structp png_ptr)
 png_uint_32 PNGAPI
 png_get_io_chunk_type (png_const_structp png_ptr)
 {
-   return ((png_ptr->chunk_name[0] << 24) +
-           (png_ptr->chunk_name[1] << 16) +
-           (png_ptr->chunk_name[2] <<  8) +
-           (png_ptr->chunk_name[3]));
+   return png_ptr->chunk_name;
 }
 
 png_const_bytep PNGAPI
 png_get_io_chunk_name (png_structp png_ptr)
 {
-   return png_ptr->chunk_name;
+   PNG_CSTRING_FROM_CHUNK(png_ptr->io_chunk_string, png_ptr->chunk_name);
+   return png_ptr->io_chunk_string;
 }
 #endif /* ?PNG_IO_STATE_SUPPORTED */
 

pnginfo.h

@@ -138,7 +138,6 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
     * single color specified that should be treated as fully transparent.
     * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
     */
-   png_bytep trans;    /* alpha values for paletted image */
    png_bytep trans_alpha;    /* alpha values for paletted image */
    png_color_16 trans_color; /* transparent color for non-palette image */
 #endif

pngmem.c

@@ -1,7 +1,7 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.5.3 [(PENDING RELEASE)]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 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.)

pngpread.c

@@ -1,7 +1,7 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.6 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 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.)
@@ -208,61 +208,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
 void /* PRIVATE */
 png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 {
-      PNG_IHDR;
-      PNG_IDAT;
-      PNG_IEND;
-      PNG_PLTE;
-#ifdef PNG_READ_bKGD_SUPPORTED
-      PNG_bKGD;
-#endif
-#ifdef PNG_READ_cHRM_SUPPORTED
-      PNG_cHRM;
-#endif
-#ifdef PNG_READ_gAMA_SUPPORTED
-      PNG_gAMA;
-#endif
-#ifdef PNG_READ_hIST_SUPPORTED
-      PNG_hIST;
-#endif
-#ifdef PNG_READ_iCCP_SUPPORTED
-      PNG_iCCP;
-#endif
-#ifdef PNG_READ_iTXt_SUPPORTED
-      PNG_iTXt;
-#endif
-#ifdef PNG_READ_oFFs_SUPPORTED
-      PNG_oFFs;
-#endif
-#ifdef PNG_READ_pCAL_SUPPORTED
-      PNG_pCAL;
-#endif
-#ifdef PNG_READ_pHYs_SUPPORTED
-      PNG_pHYs;
-#endif
-#ifdef PNG_READ_sBIT_SUPPORTED
-      PNG_sBIT;
-#endif
-#ifdef PNG_READ_sCAL_SUPPORTED
-      PNG_sCAL;
-#endif
-#ifdef PNG_READ_sRGB_SUPPORTED
-      PNG_sRGB;
-#endif
-#ifdef PNG_READ_sPLT_SUPPORTED
-      PNG_sPLT;
-#endif
-#ifdef PNG_READ_tEXt_SUPPORTED
-      PNG_tEXt;
-#endif
-#ifdef PNG_READ_tIME_SUPPORTED
-      PNG_tIME;
-#endif
-#ifdef PNG_READ_tRNS_SUPPORTED
-      PNG_tRNS;
-#endif
-#ifdef PNG_READ_zTXt_SUPPORTED
-      PNG_zTXt;
-#endif
+   png_uint_32 chunk_name;
 
    /* 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
@@ -273,6 +219,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
    {
       png_byte chunk_length[4];
+      png_byte chunk_tag[4];
 
       if (png_ptr->buffer_size < 8)
       {
@@ -283,16 +230,19 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
       png_push_fill_buffer(png_ptr, chunk_length, 4);
       png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
-      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+      png_crc_read(png_ptr, chunk_tag, 4);
+      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
       png_check_chunk_name(png_ptr, png_ptr->chunk_name);
       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
    }
 
-   if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+   chunk_name = png_ptr->chunk_name;
+
+   if (chunk_name == png_IDAT)
       if (png_ptr->mode & PNG_AFTER_IDAT)
          png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
 
-   if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
+   if (chunk_name == png_IHDR)
    {
       if (png_ptr->push_length != 13)
          png_error(png_ptr, "Invalid IHDR length");
@@ -306,7 +256,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
       png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
    }
 
-   else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+   else if (chunk_name == png_IEND)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -321,7 +271,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+   else if (png_chunk_unknown_handling(png_ptr, chunk_name))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -329,15 +279,15 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
          return;
       }
 
-      if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      if (chunk_name == png_IDAT)
          png_ptr->mode |= PNG_HAVE_IDAT;
 
       png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
 
-      if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+      if (chunk_name == png_PLTE)
          png_ptr->mode |= PNG_HAVE_PLTE;
 
-      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      else if (chunk_name == png_IDAT)
       {
          if (!(png_ptr->mode & PNG_HAVE_IHDR))
             png_error(png_ptr, "Missing IHDR before IDAT");
@@ -349,7 +299,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-   else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+   else if (chunk_name == png_PLTE)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -359,7 +309,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
       png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
    }
 
-   else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+   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
@@ -395,7 +345,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #ifdef PNG_READ_gAMA_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
+   else if (png_ptr->chunk_name == png_gAMA)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -408,7 +358,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_sBIT_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
+   else if (png_ptr->chunk_name == png_sBIT)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -421,7 +371,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_cHRM_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
+   else if (png_ptr->chunk_name == png_cHRM)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -434,7 +384,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_sRGB_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
+   else if (chunk_name == png_sRGB)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -447,7 +397,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_iCCP_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+   else if (png_ptr->chunk_name == png_iCCP)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -460,7 +410,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_sPLT_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+   else if (chunk_name == png_sPLT)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -473,7 +423,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_tRNS_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
+   else if (chunk_name == png_tRNS)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -486,7 +436,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_bKGD_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
+   else if (chunk_name == png_bKGD)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -499,7 +449,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_hIST_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
+   else if (chunk_name == png_hIST)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -512,7 +462,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_pHYs_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
+   else if (chunk_name == png_pHYs)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -525,7 +475,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_oFFs_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
+   else if (chunk_name == png_oFFs)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -538,7 +488,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 #endif
 
 #ifdef PNG_READ_pCAL_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
+   else if (chunk_name == png_pCAL)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -551,7 +501,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_sCAL_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+   else if (chunk_name == png_sCAL)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -564,7 +514,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_tIME_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
+   else if (chunk_name == png_tIME)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -577,7 +527,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_tEXt_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
+   else if (chunk_name == png_tEXt)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -590,7 +540,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_zTXt_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
+   else if (chunk_name == png_zTXt)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -603,7 +553,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
 #endif
 #ifdef PNG_READ_iTXt_SUPPORTED
-   else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+   else if (chunk_name == png_iTXt)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -809,11 +759,12 @@ png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
 void /* PRIVATE */
 png_push_read_IDAT(png_structp png_ptr)
 {
-   PNG_IDAT;
    if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
    {
       png_byte chunk_length[4];
+      png_byte chunk_tag[4];
 
+      /* TODO: this code can be commoned up with the same code in push_read */
       if (png_ptr->buffer_size < 8)
       {
          png_push_save_buffer(png_ptr);
@@ -823,10 +774,11 @@ png_push_read_IDAT(png_structp png_ptr)
       png_push_fill_buffer(png_ptr, chunk_length, 4);
       png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
-      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+      png_crc_read(png_ptr, chunk_tag, 4);
+      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
 
-      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      if (png_ptr->chunk_name != png_IDAT)
       {
          png_ptr->process_mode = PNG_READ_CHUNK_MODE;
 
@@ -838,6 +790,7 @@ png_push_read_IDAT(png_structp png_ptr)
 
       png_ptr->idat_size = png_ptr->push_length;
    }
+
    if (png_ptr->idat_size && png_ptr->save_buffer_size)
    {
       png_size_t save_size = png_ptr->save_buffer_size;
@@ -1011,34 +964,56 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
 void /* PRIVATE */
 png_push_process_row(png_structp png_ptr)
 {
-   png_ptr->row_info.color_type = png_ptr->color_type;
-   png_ptr->row_info.width = png_ptr->iwidth;
-   png_ptr->row_info.channels = png_ptr->channels;
-   png_ptr->row_info.bit_depth = png_ptr->bit_depth;
-   png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
+   /* 1.5.6: row_info moved out of png_struct to a local here. */
+   png_row_info row_info;
 
-   png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
-       png_ptr->row_info.width);
+   row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+   row_info.color_type = png_ptr->color_type;
+   row_info.bit_depth = png_ptr->bit_depth;
+   row_info.channels = png_ptr->channels;
+   row_info.pixel_depth = png_ptr->pixel_depth;
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
 
-   png_read_filter_row(png_ptr, &(png_ptr->row_info),
-       png_ptr->row_buf + 1, png_ptr->prev_row + 1,
-       (int)(png_ptr->row_buf[0]));
+   if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+   {
+      if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+         png_read_filter_row(&row_info, png_ptr->row_buf + 1,
+            png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+      else
+         png_error(png_ptr, "bad adaptive filter value");
+   }
 
-   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
+   /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+    * 1.5.6, while the buffer really is this big in current versions of libpng
+    * 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);
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
    if (png_ptr->transformations)
-      png_do_read_transformations(png_ptr);
+      png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+   /* The transformed pixel depth should match the depth now in row_info. */
+   if (png_ptr->transformed_pixel_depth == 0)
+   {
+      png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+      if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+         png_error(png_ptr, "progressive row overflow");
+   }
+
+   else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+      png_error(png_ptr, "internal progressive row size calculation error");
+
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Blow up interlaced rows to full size */
    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
    {
       if (png_ptr->pass < 6)
-/*       old interface (pre-1.0.9):
-         png_do_read_interlace(&(png_ptr->row_info),
-             png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
- */
-         png_do_read_interlace(png_ptr);
+         png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+            png_ptr->transformations);
 
     switch (png_ptr->pass)
     {
@@ -1221,20 +1196,20 @@ png_read_push_finish_row(png_structp png_ptr)
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
-   PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+   static PNG_CONST png_byte FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
 
    /* Offset to next interlace block */
-   PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST png_byte FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
 
    /* Start of interlace block in the y direction */
-   PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+   static PNG_CONST png_byte FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
 
    /* Offset to next interlace block in the y direction */
-   PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+   static PNG_CONST png_byte FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
 
    /* Height of interlace block.  This is not currently used - if you need
     * it, uncomment it here and in png.h
-   PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST png_byte FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
    */
 
    png_ptr->row_number++;
@@ -1288,7 +1263,7 @@ png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
       {
          PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
          png_error(png_ptr, "Out of place tEXt");
-         /*NOT REACHED*/
+         /* NOT REACHED */
       }
 
 #ifdef PNG_MAX_MALLOC_64K
@@ -1385,7 +1360,7 @@ png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
    {
       PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
       png_error(png_ptr, "Out of place zTXt");
-      /*NOT REACHED*/
+      /* NOT REACHED */
    }
 
 #ifdef PNG_MAX_MALLOC_64K
@@ -1589,7 +1564,7 @@ png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
    {
       PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
       png_error(png_ptr, "Out of place iTXt");
-      /*NOT REACHED*/
+      /* NOT REACHED */
    }
 
 #ifdef PNG_MAX_MALLOC_64K
@@ -1712,11 +1687,12 @@ png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
     length)
 {
    png_uint_32 skip = 0;
+   png_uint_32 chunk_name = png_ptr->chunk_name;
 
-   if (!(png_ptr->chunk_name[0] & 0x20))
+   if (PNG_CHUNK_CRITICAL(chunk_name))
    {
 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-      if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+      if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
           PNG_HANDLE_CHUNK_ALWAYS
 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
           && png_ptr->read_user_chunk_fn == NULL
@@ -1729,22 +1705,26 @@ png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
    }
 
 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   /* TODO: the code below is apparently just using the
+    * png_struct::unknown_chunk member as a temporarily variable, it should be
+    * possible to eliminate both it and the temporary buffer.
+    */
    if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
    {
 #ifdef PNG_MAX_MALLOC_64K
-      if (length > (png_uint_32)65535L)
+      if (length > 65535)
       {
          png_warning(png_ptr, "unknown chunk too large to fit in memory");
-         skip = length - (png_uint_32)65535L;
-         length = (png_uint_32)65535L;
+         skip = length - 65535;
+         length = 65535;
       }
 #endif
-      png_memcpy((png_charp)png_ptr->unknown_chunk.name,
-          (png_charp)png_ptr->chunk_name,
-          png_sizeof(png_ptr->unknown_chunk.name));
-      png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
-          = '\0';
+      /* This is just a record for the user; libpng doesn't use the character
+       * form of the name.
+       */
+      PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
 
+      /* The following cast should be safe because of the check above. */
       png_ptr->unknown_chunk.size = (png_size_t)length;
 
       if (length == 0)
@@ -1753,8 +1733,9 @@ png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
       else
       {
          png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
-             (png_size_t)length);
-         png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
+            png_ptr->unknown_chunk.size);
+         png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data,
+            png_ptr->unknown_chunk.size);
       }
 
 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
@@ -1770,8 +1751,8 @@ png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
 
          if (ret == 0)
          {
-            if (!(png_ptr->chunk_name[0] & 0x20))
-               if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+            if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+               if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
                    PNG_HANDLE_CHUNK_ALWAYS)
                   png_chunk_error(png_ptr, "unknown critical chunk");
             png_set_unknown_chunks(png_ptr, info_ptr,
@@ -1818,7 +1799,7 @@ void PNGAPI
 png_progressive_combine_row (png_structp png_ptr, png_bytep old_row,
     png_const_bytep new_row)
 {
-   PNG_CONST int FARDATA png_pass_dsp_mask[7] =
+   static PNG_CONST png_byte FARDATA png_pass_dsp_mask[7] =
       {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
 
    if (png_ptr == NULL)

pngpriv.h

@@ -6,7 +6,7 @@
  * (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 1.5.3 [(PENDING RELEASE)]
+ * Last changed in libpng 1.5.5 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -25,12 +25,27 @@
 #ifndef PNGPRIV_H
 #define PNGPRIV_H
 
+/* Feature Test Macros.  The following are defined here to ensure that correctly
+ * implemented libraries reveal the APIs libpng needs to build and hide those
+ * that are not needed and potentially damaging to the compilation.
+ *
+ * Feature Test Macros must be defined before any system header is included (see
+ * POSIX 1003.1 2.8.2 "POSIX Symbols."
+ *
+ * These macros only have an effect if the operating system supports either
+ * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
+ * Windows/Visual Studio) there is no effect; the OS specific tests below are
+ * still required (as of 2011-05-02.)
+ */
+#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
+
 /* This is required for the definition of abort(), used as a last ditch
  * error handler when all else fails.
  */
 #include <stdlib.h>
 
-#define PNGLIB_BUILD
+#define PNGLIB_BUILD /*libpng is being built, not used*/
+
 #ifdef PNG_USER_CONFIG
 #  include "pngusr.h"
    /* These should have been defined in pngusr.h */
@@ -41,10 +56,80 @@
 #    define PNG_USER_DLLFNAME_POSTFIX "Cb"
 #  endif
 #endif
+
+/* Is this a build of a DLL where compilation of the object modules requires
+ * different preprocessor settings to those required for a simple library?  If
+ * so PNG_BUILD_DLL must be set.
+ *
+ * If libpng is used inside a DLL but that DLL does not export the libpng APIs
+ * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
+ * static library of libpng then link the DLL against that.
+ */
+#ifndef PNG_BUILD_DLL
+#  ifdef DLL_EXPORT
+      /* This is set by libtool when files are compiled for a DLL; libtool
+       * always compiles twice, even on systems where it isn't necessary.  Set
+       * PNG_BUILD_DLL in case it is necessary:
+       */
+#     define PNG_BUILD_DLL
+#  else
+#     ifdef _WINDLL
+         /* This is set by the Microsoft Visual Studio IDE in projects that
+          * build a DLL.  It can't easily be removed from those projects (it
+          * isn't visible in the Visual Studio UI) so it is a fairly reliable
+          * indication that PNG_IMPEXP needs to be set to the DLL export
+          * attributes.
+          */
+#        define PNG_BUILD_DLL
+#     else
+#        ifdef __DLL__
+            /* This is set by the Borland C system when compiling for a DLL
+             * (as above.)
+             */
+#           define PNG_BUILD_DLL
+#        else
+            /* Add additional compiler cases here. */
+#        endif
+#     endif
+#  endif
+#endif /* Setting PNG_BUILD_DLL if required */
+
+/* See pngconf.h for more details: the builder of the library may set this on
+ * the command line to the right thing for the specific compilation system or it
+ * may be automagically set above (at present we know of no system where it does
+ * need to be set on the command line.)
+ *
+ * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
+ * setting it to the "import" setting for a DLL build.
+ */
+#ifndef PNG_IMPEXP
+#  ifdef PNG_BUILD_DLL
+#     define PNG_IMPEXP PNG_DLL_EXPORT
+#  else
+      /* Not building a DLL, or the DLL doesn't require specific export
+       * definitions.
+       */
+#     define PNG_IMPEXP
+#  endif
+#endif
+
+/* No warnings for private or deprecated functions in the build: */
+#ifndef PNG_DEPRECATED
+#  define PNG_DEPRECATED
+#endif
+#ifndef PNG_PRIVATE
+#  define PNG_PRIVATE
+#endif
+
 #include "png.h"
 #include "pnginfo.h"
 #include "pngstruct.h"
 
+/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
+#ifndef PNG_DLL_EXPORT
+#  define PNG_DLL_EXPORT
+#endif
+
 /* This is used for 16 bit gamma tables - only the top level pointers are const,
  * this could be changed:
  */
@@ -101,12 +186,27 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #  define PNG_ZBUF_SIZE 65536L
 #endif
 
-/* If warnings or errors are turned off the code is disabled
- * or redirected here.
+/* PNG_STATIC is used to mark internal file scope functions if they need to be
+ * accessed for implementation tests (see the code in tests/?*).
  */
-#ifndef PNG_WARNINGS_SUPPORTED
-#  define png_warning(s1,s2) ((void)0)
-#  define png_chunk_warning(s1,s2) ((void)0)
+#ifndef PNG_STATIC
+#   define PNG_STATIC static
+#endif
+
+/* If warnings or errors are turned off the code is disabled or redirected here.
+ * From 1.5.4 functions have been added to allow very limited formatting of
+ * error and warning messages - this code will also be disabled here.
+ */
+#ifdef PNG_WARNINGS_SUPPORTED
+#  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
+#else
+#  define png_warning(s1,s2) ((void)(s1))
+#  define png_chunk_warning(s1,s2) ((void)(s1))
+#  define png_warning_parameter(p,number,string) ((void)0)
+#  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
+#  define png_warning_parameter_signed(p,number,format,value) ((void)0)
+#  define png_formatted_warning(pp,p,message) ((void)(pp))
+#  define PNG_WARNING_PARAMETERS(p)
 #endif
 #ifndef PNG_ERROR_TEXT_SUPPORTED
 #  define png_error(s1,s2) png_err(s1)
@@ -200,60 +300,28 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #  define NOCHECK 0
 #  define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
 #  define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
-#  define png_strcpy  _fstrcpy
-#  define png_strncpy _fstrncpy   /* Added to v 1.2.6 */
 #  define png_strlen  _fstrlen
 #  define png_memcmp  _fmemcmp    /* SJT: added */
 #  define png_memcpy  _fmemcpy
 #  define png_memset  _fmemset
-#  define png_sprintf sprintf
 #else
 #  ifdef _WINDOWS_  /* Favor Windows over C runtime fns */
 #    define CVT_PTR(ptr)         (ptr)
 #    define CVT_PTR_NOCHECK(ptr) (ptr)
-#    define png_strcpy  lstrcpyA
-#    define png_strncpy lstrcpynA
 #    define png_strlen  lstrlenA
 #    define png_memcmp  memcmp
 #    define png_memcpy  CopyMemory
 #    define png_memset  memset
-#    define png_sprintf wsprintfA
 #  else
 #    define CVT_PTR(ptr)         (ptr)
 #    define CVT_PTR_NOCHECK(ptr) (ptr)
-#    define png_strcpy  strcpy
-#    define png_strncpy strncpy     /* Added to v 1.2.6 */
 #    define png_strlen  strlen
 #    define png_memcmp  memcmp      /* SJT: added */
 #    define png_memcpy  memcpy
 #    define png_memset  memset
-#    define png_sprintf sprintf
 #  endif
 #endif
 /* End of memory model/platform independent support */
-
-#ifndef PNG_NO_SNPRINTF
-#  ifdef _MSC_VER
-#    define png_snprintf _snprintf   /* Added to v 1.2.19 */
-#    define png_snprintf2 _snprintf
-#    define png_snprintf6 _snprintf
-#  else
-#    define png_snprintf snprintf   /* Added to v 1.2.19 */
-#    define png_snprintf2 snprintf
-#    define png_snprintf6 snprintf
-#  endif
-#else
-  /* You don't have or don't want to use snprintf().  Caution: Using
-   * sprintf instead of snprintf exposes your application to accidental
-   * or malevolent buffer overflows.  If you don't have snprintf()
-   * as a general rule you should provide one (you can get one from
-   * Portable OpenSSH).
-   */
-#  define png_snprintf(s1,n,fmt,x1) png_sprintf(s1,fmt,x1)
-#  define png_snprintf2(s1,n,fmt,x1,x2) png_sprintf(s1,fmt,x1,x2)
-#  define png_snprintf6(s1,n,fmt,x1,x2,x3,x4,x5,x6) \
-      png_sprintf(s1,fmt,x1,x2,x3,x4,x5,x6)
-#endif
 /* End of 1.5.0beta36 move from pngconf.h */
 
 /* CONSTANTS and UTILITY MACROS
@@ -261,12 +329,14 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
  */
 
 /* Various modes of operation.  Note that after an init, mode is set to
- * zero automatically when the structure is created.
+ * zero automatically when the structure is created.  Three of these
+ * are defined in png.h because they need to be visible to applications
+ * that call png_set_unknown_chunk().
  */
-#define PNG_HAVE_IHDR               0x01
-#define PNG_HAVE_PLTE               0x02
+/* #define PNG_HAVE_IHDR            0x01 (defined in png.h) */
+/* #define PNG_HAVE_PLTE            0x02 (defined in png.h) */
 #define PNG_HAVE_IDAT               0x04
-#define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
+/* #define PNG_AFTER_IDAT           0x08 (defined in png.h) */
 #define PNG_HAVE_IEND               0x10
 #define PNG_HAVE_gAMA               0x20
 #define PNG_HAVE_cHRM               0x40
@@ -277,7 +347,6 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #define PNG_BACKGROUND_IS_GRAY     0x800
 #define PNG_HAVE_PNG_SIGNATURE    0x1000
 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
-#define PNG_ZLIB_READY_FOR_ZTXT   0x4000 /* 1: ready for ZTXT; 0: for IDAT */
 
 /* Flags for the transformations the PNG library does on the image data */
 #define PNG_BGR                 0x0001
@@ -287,32 +356,31 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #define PNG_SWAP_BYTES          0x0010
 #define PNG_INVERT_MONO         0x0020
 #define PNG_QUANTIZE            0x0040
-#define PNG_BACKGROUND          0x0080
+#define PNG_COMPOSE             0x0080     /* Was PNG_BACKGROUND */
 #define PNG_BACKGROUND_EXPAND   0x0100
 #define PNG_EXPAND_16           0x0200     /* Added to libpng 1.5.2 */
-#define PNG_16_TO_8             0x0400
+#define PNG_16_TO_8             0x0400     /* Becomes 'chop' in 1.5.4 */
 #define PNG_RGBA                0x0800
 #define PNG_EXPAND              0x1000
 #define PNG_GAMMA               0x2000
 #define PNG_GRAY_TO_RGB         0x4000
-#define PNG_FILLER              0x8000L
-#define PNG_PACKSWAP           0x10000L
-#define PNG_SWAP_ALPHA         0x20000L
-#define PNG_STRIP_ALPHA        0x40000L
-#define PNG_INVERT_ALPHA       0x80000L
-#define PNG_USER_TRANSFORM    0x100000L
-#define PNG_RGB_TO_GRAY_ERR   0x200000L
-#define PNG_RGB_TO_GRAY_WARN  0x400000L
-#define PNG_RGB_TO_GRAY       0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
-                       /*     0x800000L     Unused */
-#define PNG_ADD_ALPHA         0x1000000L  /* Added to libpng-1.2.7 */
-#define PNG_EXPAND_tRNS       0x2000000L  /* Added to libpng-1.2.9 */
-                       /*   0x4000000L  unused */
-                       /*   0x8000000L  unused */
-                       /*  0x10000000L  unused */
-                       /*  0x20000000L  unused */
-                       /*  0x40000000L  unused */
-
+#define PNG_FILLER              0x8000
+#define PNG_PACKSWAP           0x10000
+#define PNG_SWAP_ALPHA         0x20000
+#define PNG_STRIP_ALPHA        0x40000
+#define PNG_INVERT_ALPHA       0x80000
+#define PNG_USER_TRANSFORM    0x100000
+#define PNG_RGB_TO_GRAY_ERR   0x200000
+#define PNG_RGB_TO_GRAY_WARN  0x400000
+#define PNG_RGB_TO_GRAY       0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
+#define PNG_ENCODE_ALPHA      0x800000 /* Added to libpng-1.5.4 */
+#define PNG_ADD_ALPHA         0x1000000 /* Added to libpng-1.2.7 */
+#define PNG_EXPAND_tRNS       0x2000000 /* Added to libpng-1.2.9 */
+#define PNG_SCALE_16_TO_8     0x4000000 /* Added to libpng-1.5.4 */
+                       /*   0x8000000 unused */
+                       /*  0x10000000 unused */
+                       /*  0x20000000 unused */
+                       /*  0x40000000 unused */
 /* Flags for png_create_struct */
 #define PNG_STRUCT_PNG   0x0001
 #define PNG_STRUCT_INFO  0x0002
@@ -334,25 +402,25 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
-                                /*        0x1000  unused */
-                                /*        0x2000  unused */
-                                /*        0x4000  unused */
-#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
-#define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
-#define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
-#define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
-#define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
-#define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
-                                  /*      0x200000L  unused */
-                                  /*      0x400000L  unused */
-#define PNG_FLAG_BENIGN_ERRORS_WARN       0x800000L  /* Added to libpng-1.4.0 */
-#define PNG_FLAG_ZTXT_CUSTOM_STRATEGY    0x1000000L  /* 5 lines added */
-#define PNG_FLAG_ZTXT_CUSTOM_LEVEL       0x2000000L  /* to libpng-1.5.3 */
-#define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL   0x4000000L
-#define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000L
-#define PNG_FLAG_ZTXT_CUSTOM_METHOD      0x10000000L
-                                  /*     0x20000000L  unused */
-                                  /*     0x40000000L  unused */
+#define PNG_FLAG_ASSUME_sRGB              0x1000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_OPTIMIZE_ALPHA           0x2000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_DETECT_UNINITIALIZED     0x4000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000
+#define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000
+#define PNG_FLAG_LIBRARY_MISMATCH         0x20000
+#define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000
+#define PNG_FLAG_STRIP_ERROR_TEXT         0x80000
+#define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000
+                                  /*      0x200000  unused */
+                                  /*      0x400000  unused */
+#define PNG_FLAG_BENIGN_ERRORS_WARN       0x800000  /* Added to libpng-1.4.0 */
+#define PNG_FLAG_ZTXT_CUSTOM_STRATEGY    0x1000000  /* 5 lines added */
+#define PNG_FLAG_ZTXT_CUSTOM_LEVEL       0x2000000  /* to libpng-1.5.4 */
+#define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL   0x4000000
+#define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000
+#define PNG_FLAG_ZTXT_CUSTOM_METHOD      0x10000000
+                                  /*     0x20000000  unused */
+                                  /*     0x40000000  unused */
 
 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
@@ -434,32 +502,75 @@ PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp,
 #endif
 #endif
 
-/* Constant strings for known chunk types.  If you need to add a chunk,
- * define the name here, and add an invocation of the macro wherever it's
- * needed.
+/* Constants for known chunk types.  If you need to add a chunk, define the name
+ * here.  For historical reasons these constants have the form png_<name>; i.e.
+ * the prefix is lower case.  Please use decimal values as the parameters to
+ * match the ISO PNG specification and to avoid relying on the C locale
+ * interpretation of character values.
+ *
+ * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
+ * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
+ * to be generated if required.
+ *
+ * PNG_32b correctly produces a value shifted by up to 24 bits, even on
+ * architectures where (int) is only 16 bits.
  */
-#define PNG_IHDR PNG_CONST png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
-#define PNG_IDAT PNG_CONST png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
-#define PNG_IEND PNG_CONST png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
-#define PNG_PLTE PNG_CONST png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
-#define PNG_bKGD PNG_CONST png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
-#define PNG_cHRM PNG_CONST png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
-#define PNG_gAMA PNG_CONST png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
-#define PNG_hIST PNG_CONST png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
-#define PNG_iCCP PNG_CONST png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
-#define PNG_iTXt PNG_CONST png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
-#define PNG_oFFs PNG_CONST png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
-#define PNG_pCAL PNG_CONST png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
-#define PNG_sCAL PNG_CONST png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
-#define PNG_pHYs PNG_CONST png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
-#define PNG_sBIT PNG_CONST png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
-#define PNG_sPLT PNG_CONST png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
-#define PNG_sRGB PNG_CONST png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
-#define PNG_sTER PNG_CONST png_byte png_sTER[5] = {115,  84,  69,  82, '\0'}
-#define PNG_tEXt PNG_CONST png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
-#define PNG_tIME PNG_CONST png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
-#define PNG_tRNS PNG_CONST png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
-#define PNG_zTXt PNG_CONST png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
+#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
+#define PNG_CHUNK(b1,b2,b3,b4) \
+   (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
+
+#define png_IHDR PNG_CHUNK( 73,  72,  68,  82)
+#define png_IDAT PNG_CHUNK( 73,  68,  65,  84)
+#define png_IEND PNG_CHUNK( 73,  69,  78,  68)
+#define png_PLTE PNG_CHUNK( 80,  76,  84,  69)
+#define png_bKGD PNG_CHUNK( 98,  75,  71,  68)
+#define png_cHRM PNG_CHUNK( 99,  72,  82,  77)
+#define png_gAMA PNG_CHUNK(103,  65,  77,  65)
+#define png_hIST PNG_CHUNK(104,  73,  83,  84)
+#define png_iCCP PNG_CHUNK(105,  67,  67,  80)
+#define png_iTXt PNG_CHUNK(105,  84,  88, 116)
+#define png_oFFs PNG_CHUNK(111,  70,  70, 115)
+#define png_pCAL PNG_CHUNK(112,  67,  65,  76)
+#define png_sCAL PNG_CHUNK(115,  67,  65,  76)
+#define png_pHYs PNG_CHUNK(112,  72,  89, 115)
+#define png_sBIT PNG_CHUNK(115,  66,  73,  84)
+#define png_sPLT PNG_CHUNK(115,  80,  76,  84)
+#define png_sRGB PNG_CHUNK(115,  82,  71,  66)
+#define png_sTER PNG_CHUNK(115,  84,  69,  82)
+#define png_tEXt PNG_CHUNK(116,  69,  88, 116)
+#define png_tIME PNG_CHUNK(116,  73,  77,  69)
+#define png_tRNS PNG_CHUNK(116,  82,  78,  83)
+#define png_zTXt PNG_CHUNK(122,  84,  88, 116)
+
+/* The following will work on (signed char*) strings, whereas the get_uint_32
+ * macro will fail on top-bit-set values because of the sign extension.
+ */
+#define PNG_CHUNK_FROM_STRING(s)\
+   PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
+
+/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
+ * signed and the argument is a (char[])  This macro will fail miserably on
+ * systems where (char) is more than 8 bits.
+ */
+#define PNG_STRING_FROM_CHUNK(s,c)\
+   (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
+   ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
+
+/* Do the same but terminate with a null character. */
+#define PNG_CSTRING_FROM_CHUNK(s,c)\
+   (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
+
+/* Test on flag values as defined in the spec (section 5.4): */
+#define PNG_CHUNK_ANCILLIARY(c)   (1 & ((c) >> 29))
+#define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLIARY(c))
+#define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
+#define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
+#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
+
+/* Gamma values (new at libpng-1.5.4): */
+#define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
+#define PNG_GAMMA_MAC_INVERSE 65909
+#define PNG_GAMMA_sRGB_INVERSE 45455
 
 
 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
@@ -473,6 +584,12 @@ extern "C" {
  * be found in the files where the functions are located.
  */
 
+/* Check the user version string for compatibility, returns false if the version
+ * numbers aren't compatible.
+ */
+PNG_EXTERN int png_user_version_check(png_structp png_ptr,
+   png_const_charp user_png_ver);
+
 /* Allocate memory for an internal libpng struct */
 PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)),
    PNG_ALLOCATED);
@@ -705,17 +822,20 @@ PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
 /* Internal use only.   Called before first row of data */
 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
 
-/* Combine a row of data, dealing with alpha, etc. if requested */
+/* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
+ * array of png_ptr->width pixels, 'mask' is a mask of the pixels to copy from
+ * png_ptr->row_buf+1.  'mask' describes each block of 8 pixels - only the low 8
+ * bits are used.  This function is only ever used to write to row buffers
+ * provided by the caller of the relevant libpng API and the row must have
+ * already been transformed by the read transformations.
+ */
 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
     int mask));
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
 /* Expand an interlaced row */
-/* OLD pre-1.0.9 interface:
 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
     png_bytep row, int pass, png_uint_32 transformations));
- */
-PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
 #endif
 
 /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
@@ -726,26 +846,27 @@ PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
     png_bytep row, int pass));
 #endif
 
-/* Unfilter a row */
-PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
-    png_row_infop row_info, png_bytep row, png_const_bytep prev_row,
-    int filter));
+/* Unfilter a row: check the filter value before calling this, there is no point
+ * calling it for PNG_FILTER_VALUE_NONE.
+ */
+PNG_EXTERN void png_read_filter_row PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row, int filter));
 
 /* Choose the best filter to use and filter the row data */
 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
     png_row_infop row_info));
 
-/* Write out the filtered row. */
-PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
-    png_bytep filtered_row));
 /* Finish a row while reading, dealing with interlacing passes, etc. */
 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
 
 /* Initialize the row buffers, etc. */
 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 /* Optional call to update the users info structure */
 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
     png_infop info_ptr));
+#endif
 
 /* These are the functions that do the transformations */
 #ifdef PNG_READ_FILLER_SUPPORTED
@@ -817,7 +938,12 @@ PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
     png_bytep row));
 #endif
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+PNG_EXTERN void png_do_scale_16_to_8 PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
     png_bytep row));
 #endif
@@ -848,26 +974,20 @@ PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info,
     png_bytep row, png_const_color_8p bit_depth));
 #endif
 
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
-#  ifdef PNG_READ_GAMMA_SUPPORTED
-PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info,
-    png_bytep row, png_const_color_16p trans_color,
-    png_const_color_16p background, png_const_color_16p background_1,
-    png_const_bytep gamma_table, png_const_bytep gamma_from_1,
-    png_const_bytep gamma_to_1, png_const_uint_16pp gamma_16,
-    png_const_uint_16pp gamma_16_from_1, png_const_uint_16pp gamma_16_to_1,
-    int gamma_shift));
-#  else
-PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info,
-    png_bytep row, png_const_color_16p trans_color,
-    png_const_color_16p background));
-#  endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+    defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+PNG_EXTERN void png_do_compose PNGARG((png_row_infop row_info,
+    png_bytep row, png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info,
-    png_bytep row, png_const_bytep gamma_table,
-    png_const_uint_16pp gamma_16_table, int gamma_shift));
+    png_bytep row, png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+PNG_EXTERN void png_do_encode_alpha PNGARG((png_row_infop row_info,
+   png_bytep row, png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
@@ -980,17 +1100,35 @@ PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
     png_uint_32 length));
 #endif
 
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
     png_infop info_ptr, png_uint_32 length));
+#endif
 
 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
-    png_const_bytep chunk_name));
+    png_uint_32 chunk_name));
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+/* Exactly as png_handle_as_unknown() except that the argument is a 32-bit chunk
+ * name, not a string.
+ */
+PNG_EXTERN int png_chunk_unknown_handling PNGARG((png_structp png_ptr,
+    png_uint_32 chunk_name));
+#endif
 
 /* Handle the transformations for reading and writing */
-PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
-PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr,
+   png_row_infop row_info));
+#endif
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr,
+   png_row_infop row_info));
+#endif
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
+#endif
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
@@ -1064,6 +1202,35 @@ PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
     unsigned long *hi_product, unsigned long *lo_product));
 #endif
 
+#ifdef PNG_cHRM_SUPPORTED
+/* Added at libpng version 1.5.5 */
+typedef struct png_xy
+{
+   png_fixed_point redx, redy;
+   png_fixed_point greenx, greeny;
+   png_fixed_point bluex, bluey;
+   png_fixed_point whitex, whitey;
+} 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_XYZ;
+
+/* The conversion APIs return 0 on success, non-zero on a parameter error. They
+ * allow conversion between the above representations of a color encoding.  When
+ * converting from XYZ end points to chromaticities the absolute magnitude of
+ * the end points is lost, when converting back the sum of the Y values of the
+ * three end points will be 1.0
+ */
+PNG_EXTERN int png_xy_from_XYZ PNGARG((png_xy *xy, png_XYZ XYZ));
+PNG_EXTERN int png_XYZ_from_xy PNGARG((png_XYZ *XYZ, png_xy xy));
+PNG_EXTERN int png_XYZ_from_xy_checked PNGARG((png_structp png_ptr,
+   png_XYZ *XYZ, png_xy xy));
+#endif
+
 /* Added at libpng version 1.4.0 */
 PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
     png_uint_32 width, png_uint_32 height, int bit_depth,
@@ -1087,6 +1254,76 @@ PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr,
    png_const_charp name),PNG_NORETURN);
 #endif
 
+/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
+ * the end.  Always leaves the buffer nul terminated.  Never errors out (and
+ * there is no error code.)
+ */
+PNG_EXTERN size_t png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+    png_const_charp string);
+
+/* Various internal functions to handle formatted warning messages, currently
+ * only implemented for warnings.
+ */
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.  This utility only
+ * does unsigned values.
+ */
+PNG_EXTERN png_charp png_format_number(png_const_charp start, png_charp end,
+   int format, png_alloc_size_t number);
+
+/* Convenience macro that takes an array: */
+#define PNG_FORMAT_NUMBER(buffer,format,number) \
+   png_format_number(buffer, buffer + (sizeof buffer), format, number)
+
+/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
+#define PNG_NUMBER_BUFFER_SIZE 24
+
+/* These are the integer formats currently supported, the name is formed from
+ * the standard printf(3) format string.
+ */
+#define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
+#define PNG_NUMBER_FORMAT_02u   2
+#define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
+#define PNG_NUMBER_FORMAT_02d   2
+#define PNG_NUMBER_FORMAT_x     3
+#define PNG_NUMBER_FORMAT_02x   4
+#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* New defines and members adding in libpng-1.5.4 */
+#  define PNG_WARNING_PARAMETER_SIZE 32
+#  define PNG_WARNING_PARAMETER_COUNT 8
+
+/* An l-value of this type has to be passed to the APIs below to cache the
+ * values of the parameters to a formatted warning message.
+ */
+typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
+   PNG_WARNING_PARAMETER_SIZE];
+
+PNG_EXTERN void png_warning_parameter(png_warning_parameters p, int number,
+    png_const_charp string);
+    /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
+     * including the trailing '\0'.
+     */
+PNG_EXTERN void png_warning_parameter_unsigned(png_warning_parameters p,
+    int number, int format, png_alloc_size_t value);
+    /* Use png_alloc_size_t because it is an unsigned type as big as any we
+     * need to output.  Use the following for a signed value.
+     */
+PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p,
+    int number, int format, png_int_32 value);
+
+PNG_EXTERN void png_formatted_warning(png_structp png_ptr,
+    png_warning_parameters p, png_const_charp message);
+    /* 'message' follows the X/Open approach of using @1, @2 to insert
+     * parameters previously supplied using the above functions.  Errors in
+     * specifying the paramters will simple result in garbage substitutions.
+     */
+#endif
+
 /* ASCII to FP interfaces, currently only implemented if sCAL
  * support is required.
  */
@@ -1149,8 +1386,18 @@ PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
 #define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
 #define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
 #define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
+
+/* These three values don't affect the parser.  They are set but not used.
+ */
 #define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
-#define PNG_FP_INVALID  128  /* Available for callers as a distinct value */
+#define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
+#define PNG_FP_NONZERO  256  /* A non-zero value */
+#define PNG_FP_STICKY   448  /* The above three flags */
+
+/* This is available for the caller to store in 'state' if required.  Do not
+ * call the parser after setting it (the parser sometimes clears it.)
+ */
+#define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
 
 /* Result codes for the parser (boolean - true meants ok, false means
  * not ok yet.)
@@ -1158,6 +1405,20 @@ PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
 #define PNG_FP_MAYBE      0  /* The number may be valid in the future */
 #define PNG_FP_OK         1  /* The number is valid */
 
+/* Tests on the sticky non-zero and negative flags.  To pass these checks
+ * the state must also indicate that the whole number is valid - this is
+ * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
+ * is equivalent to PNG_FP_OK above.)
+ */
+#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
+   /* NZ_MASK: the string is valid and a non-zero negative value */
+#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
+   /* Z MASK: the string is valid and a non-zero value. */
+   /* PNG_FP_SAW_DIGIT: the string is valid. */
+#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
+#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
+#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
+ 
 /* The actual parser.  This can be called repeatedly, it updates
  * the index into the string and the state variable (which must
  * be initialzed to 0).  It returns a result code, as above.  There
@@ -1177,7 +1438,10 @@ PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string,
     png_size_t size, int *statep, png_size_tp whereami));
 
 /* This is the same but it checks a complete string and returns true
- * only if it just contains a floating point number.
+ * only if it just contains a floating point number.  As of 1.5.4 this
+ * function also returns the state at the end of parsing the number if
+ * it was valid (otherwise it returns 0.)  This can be used for testing
+ * for negative or zero values using the sticky flag.
  */
 PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string,
     png_size_t size));

pngread.c

@@ -1,7 +1,7 @@
 
 /* pngread.c - read a PNG file
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.6 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 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.)
@@ -47,12 +47,10 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
-   jmp_buf png_jmpbuf;
+   jmp_buf tmp_jmpbuf;
 #endif
 #endif
 
-   int i;
-
    png_debug(1, "in png_create_read_struct");
 
 #ifdef PNG_USER_MEM_SUPPORTED
@@ -85,13 +83,13 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
    encounter a png_error() will longjmp here.  Since the jmpbuf is
    then meaningless we abort instead of returning. */
 #ifdef USE_FAR_KEYWORD
-   if (setjmp(png_jmpbuf))
+   if (setjmp(tmp_jmpbuf))
 #else
    if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */
 #endif
       PNG_ABORT();
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 #endif
 #endif /* PNG_SETJMP_SUPPORTED */
 
@@ -101,54 +99,9 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
-   if (user_png_ver)
-   {
-      i = 0;
-
-      do
-      {
-         if (user_png_ver[i] != png_libpng_ver[i])
-            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-      } while (png_libpng_ver[i++]);
-   }
-
-   else
-      png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-
-
-   if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
-   {
-     /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
-      * we must recompile any applications that use any older library version.
-      * For versions after libpng 1.0, we will be compatible, so we need
-      * only check the first digit.
-      */
-      if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
-          (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
-          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
-      {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         char msg[80];
-         if (user_png_ver)
-         {
-            png_snprintf2(msg, 80,
-                "Application built with libpng-%.20s"
-                " but running with %.20s",
-                user_png_ver,
-                png_libpng_ver);
-            png_warning(png_ptr, msg);
-         }
-#else
-         png_warning(png_ptr,
-             "Incompatible libpng version in application and library");
-#endif
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-         png_ptr->flags = 0;
-#endif
-
-         png_cleanup_needed = 1;
-      }
-   }
+   /* Call the general version checker (shared with read and write code): */
+   if (!png_user_version_check(png_ptr, user_png_ver))
+      png_cleanup_needed = 1;
 
    if (!png_cleanup_needed)
    {
@@ -237,89 +190,35 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
 
    for (;;)
    {
-      PNG_IHDR;
-      PNG_IDAT;
-      PNG_IEND;
-      PNG_PLTE;
-#ifdef PNG_READ_bKGD_SUPPORTED
-      PNG_bKGD;
-#endif
-#ifdef PNG_READ_cHRM_SUPPORTED
-      PNG_cHRM;
-#endif
-#ifdef PNG_READ_gAMA_SUPPORTED
-      PNG_gAMA;
-#endif
-#ifdef PNG_READ_hIST_SUPPORTED
-      PNG_hIST;
-#endif
-#ifdef PNG_READ_iCCP_SUPPORTED
-      PNG_iCCP;
-#endif
-#ifdef PNG_READ_iTXt_SUPPORTED
-      PNG_iTXt;
-#endif
-#ifdef PNG_READ_oFFs_SUPPORTED
-      PNG_oFFs;
-#endif
-#ifdef PNG_READ_pCAL_SUPPORTED
-      PNG_pCAL;
-#endif
-#ifdef PNG_READ_pHYs_SUPPORTED
-      PNG_pHYs;
-#endif
-#ifdef PNG_READ_sBIT_SUPPORTED
-      PNG_sBIT;
-#endif
-#ifdef PNG_READ_sCAL_SUPPORTED
-      PNG_sCAL;
-#endif
-#ifdef PNG_READ_sPLT_SUPPORTED
-      PNG_sPLT;
-#endif
-#ifdef PNG_READ_sRGB_SUPPORTED
-      PNG_sRGB;
-#endif
-#ifdef PNG_READ_tEXt_SUPPORTED
-      PNG_tEXt;
-#endif
-#ifdef PNG_READ_tIME_SUPPORTED
-      PNG_tIME;
-#endif
-#ifdef PNG_READ_tRNS_SUPPORTED
-      PNG_tRNS;
-#endif
-#ifdef PNG_READ_zTXt_SUPPORTED
-      PNG_zTXt;
-#endif
       png_uint_32 length = png_read_chunk_header(png_ptr);
-      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
+      png_uint_32 chunk_name = png_ptr->chunk_name;
 
       /* This should be a binary subdivision search or a hash for
        * matching the chunk name rather than a linear search.
        */
-      if (!png_memcmp(chunk_name, png_IDAT, 4))
+      if (chunk_name == png_IDAT)
          if (png_ptr->mode & PNG_AFTER_IDAT)
             png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
 
-      if (!png_memcmp(chunk_name, png_IHDR, 4))
+      if (chunk_name == png_IHDR)
          png_handle_IHDR(png_ptr, info_ptr, length);
 
-      else if (!png_memcmp(chunk_name, png_IEND, 4))
+      else if (chunk_name == png_IEND)
          png_handle_IEND(png_ptr, info_ptr, length);
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      else if (png_handle_as_unknown(png_ptr, chunk_name))
+      else if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
+         PNG_HANDLE_CHUNK_AS_DEFAULT)
       {
-         if (!png_memcmp(chunk_name, png_IDAT, 4))
+         if (chunk_name == png_IDAT)
             png_ptr->mode |= PNG_HAVE_IDAT;
 
          png_handle_unknown(png_ptr, info_ptr, length);
 
-         if (!png_memcmp(chunk_name, png_PLTE, 4))
+         if (chunk_name == png_PLTE)
             png_ptr->mode |= PNG_HAVE_PLTE;
 
-         else if (!png_memcmp(chunk_name, png_IDAT, 4))
+         else if (chunk_name == png_IDAT)
          {
             if (!(png_ptr->mode & PNG_HAVE_IHDR))
                png_error(png_ptr, "Missing IHDR before IDAT");
@@ -332,10 +231,10 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
          }
       }
 #endif
-      else if (!png_memcmp(chunk_name, png_PLTE, 4))
+      else if (chunk_name == png_PLTE)
          png_handle_PLTE(png_ptr, info_ptr, length);
 
-      else if (!png_memcmp(chunk_name, png_IDAT, 4))
+      else if (chunk_name == png_IDAT)
       {
          if (!(png_ptr->mode & PNG_HAVE_IHDR))
             png_error(png_ptr, "Missing IHDR before IDAT");
@@ -350,87 +249,87 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
       }
 
 #ifdef PNG_READ_bKGD_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_bKGD, 4))
+      else if (chunk_name == png_bKGD)
          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_cHRM_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_cHRM, 4))
+      else if (chunk_name == png_cHRM)
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_gAMA_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_gAMA, 4))
+      else if (chunk_name == png_gAMA)
          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_hIST_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_hIST, 4))
+      else if (chunk_name == png_hIST)
          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_oFFs_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_oFFs, 4))
+      else if (chunk_name == png_oFFs)
          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_pCAL_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_pCAL, 4))
+      else if (chunk_name == png_pCAL)
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sCAL_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sCAL, 4))
+      else if (chunk_name == png_sCAL)
          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_pHYs_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_pHYs, 4))
+      else if (chunk_name == png_pHYs)
          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sBIT_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sBIT, 4))
+      else if (chunk_name == png_sBIT)
          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sRGB_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sRGB, 4))
+      else if (chunk_name == png_sRGB)
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_iCCP_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_iCCP, 4))
+      else if (chunk_name == png_iCCP)
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sPLT_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sPLT, 4))
+      else if (chunk_name == png_sPLT)
          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tEXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tEXt, 4))
+      else if (chunk_name == png_tEXt)
          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tIME_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tIME, 4))
+      else if (chunk_name == png_tIME)
          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tRNS_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tRNS, 4))
+      else if (chunk_name == png_tRNS)
          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_zTXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_zTXt, 4))
+      else if (chunk_name == png_zTXt)
          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_iTXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_iTXt, 4))
+      else if (chunk_name == png_iTXt)
          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
 
@@ -457,7 +356,11 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr)
           "Ignoring extra png_read_update_info() call;"
           " row buffer not reallocated");
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
    png_read_transform_info(png_ptr, info_ptr);
+#else
+   PNG_UNUSED(info_ptr)
+#endif
 }
 
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
@@ -487,7 +390,6 @@ png_start_read_image(png_structp png_ptr)
 void PNGAPI
 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 {
-   PNG_IDAT;
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
        0xff};
@@ -495,15 +397,28 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 #endif
    int ret;
 
+   png_row_info row_info;
+
    if (png_ptr == NULL)
       return;
 
    png_debug2(1, "in png_read_row (row %lu, pass %d)",
        (unsigned long)png_ptr->row_number, png_ptr->pass);
 
+   /* png_read_start_row sets the information (in particular iwidth) for this
+    * interlace pass.
+    */
    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);
 
+   /* 1.5.6: row_info moved out of png_struct to a local here. */
+   row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+   row_info.color_type = png_ptr->color_type;
+   row_info.bit_depth = png_ptr->bit_depth;
+   row_info.channels = png_ptr->channels;
+   row_info.pixel_depth = png_ptr->pixel_depth;
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
    if (png_ptr->row_number == 0 && png_ptr->pass == 0)
    {
    /* Check for transforms that have been set but were defined out */
@@ -545,7 +460,12 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
    }
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
-   /* If interlaced and we do not need a new row, combine row and return */
+   /* If interlaced and we do not need a new row, combine row and return.
+    * Notice that the pixels we have from previous rows have been transformed
+    * already; we can only combine like with like (transformed or
+    * untransformed) and, because of the libpng API for interlaced images, this
+    * means we must transform before de-interlacing.
+    */
    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
    {
       switch (png_ptr->pass)
@@ -649,7 +569,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             png_crc_finish(png_ptr, 0);
 
             png_ptr->idat_size = png_read_chunk_header(png_ptr);
-            if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+            if (png_ptr->chunk_name != png_IDAT)
                png_error(png_ptr, "Not enough image data");
          }
          png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
@@ -679,33 +599,47 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 
    } while (png_ptr->zstream.avail_out);
 
-   png_ptr->row_info.color_type = png_ptr->color_type;
-   png_ptr->row_info.width = png_ptr->iwidth;
-   png_ptr->row_info.channels = png_ptr->channels;
-   png_ptr->row_info.bit_depth = png_ptr->bit_depth;
-   png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
-   png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
-       png_ptr->row_info.width);
+   if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+   {
+      if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+         png_read_filter_row(&row_info, png_ptr->row_buf + 1,
+            png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+      else
+         png_error(png_ptr, "bad adaptive filter value");
+   }
 
-   if (png_ptr->row_buf[0])
-   png_read_filter_row(png_ptr, &(png_ptr->row_info),
-       png_ptr->row_buf + 1, png_ptr->prev_row + 1,
-       (int)(png_ptr->row_buf[0]));
-
-   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
+   /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+    * 1.5.6, while the buffer really is this big in current versions of libpng
+    * it may not be in the future, so this was changed just to copy the
+    * interlaced count:
+    */
+   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
    if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
        (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
    {
       /* Intrapixel differencing */
-      png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
+      png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1);
    }
 #endif
 
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
    if (png_ptr->transformations)
-      png_do_read_transformations(png_ptr);
+      png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+   /* The transformed pixel depth should match the depth now in row_info. */
+   if (png_ptr->transformed_pixel_depth == 0)
+   {
+      png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+      if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+         png_error(png_ptr, "sequential row overflow");
+   }
+
+   else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+      png_error(png_ptr, "internal sequential row size calculation error");
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Blow up interlaced rows to full size */
@@ -713,11 +647,8 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
       (png_ptr->transformations & PNG_INTERLACE))
    {
       if (png_ptr->pass < 6)
-         /* Old interface (pre-1.0.9):
-          * png_do_read_interlace(&(png_ptr->row_info),
-          *    png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
-          */
-         png_do_read_interlace(png_ptr);
+         png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+            png_ptr->transformations);
 
       if (dsp_row != NULL)
          png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]);
@@ -899,85 +830,31 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
 
    do
    {
-      PNG_IHDR;
-      PNG_IDAT;
-      PNG_IEND;
-      PNG_PLTE;
-#ifdef PNG_READ_bKGD_SUPPORTED
-      PNG_bKGD;
-#endif
-#ifdef PNG_READ_cHRM_SUPPORTED
-      PNG_cHRM;
-#endif
-#ifdef PNG_READ_gAMA_SUPPORTED
-      PNG_gAMA;
-#endif
-#ifdef PNG_READ_hIST_SUPPORTED
-      PNG_hIST;
-#endif
-#ifdef PNG_READ_iCCP_SUPPORTED
-      PNG_iCCP;
-#endif
-#ifdef PNG_READ_iTXt_SUPPORTED
-      PNG_iTXt;
-#endif
-#ifdef PNG_READ_oFFs_SUPPORTED
-      PNG_oFFs;
-#endif
-#ifdef PNG_READ_pCAL_SUPPORTED
-      PNG_pCAL;
-#endif
-#ifdef PNG_READ_pHYs_SUPPORTED
-      PNG_pHYs;
-#endif
-#ifdef PNG_READ_sBIT_SUPPORTED
-      PNG_sBIT;
-#endif
-#ifdef PNG_READ_sCAL_SUPPORTED
-      PNG_sCAL;
-#endif
-#ifdef PNG_READ_sPLT_SUPPORTED
-      PNG_sPLT;
-#endif
-#ifdef PNG_READ_sRGB_SUPPORTED
-      PNG_sRGB;
-#endif
-#ifdef PNG_READ_tEXt_SUPPORTED
-      PNG_tEXt;
-#endif
-#ifdef PNG_READ_tIME_SUPPORTED
-      PNG_tIME;
-#endif
-#ifdef PNG_READ_tRNS_SUPPORTED
-      PNG_tRNS;
-#endif
-#ifdef PNG_READ_zTXt_SUPPORTED
-      PNG_zTXt;
-#endif
       png_uint_32 length = png_read_chunk_header(png_ptr);
-      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
+      png_uint_32 chunk_name = png_ptr->chunk_name;
 
-      if (!png_memcmp(chunk_name, png_IHDR, 4))
+      if (chunk_name == png_IHDR)
          png_handle_IHDR(png_ptr, info_ptr, length);
 
-      else if (!png_memcmp(chunk_name, png_IEND, 4))
+      else if (chunk_name == png_IEND)
          png_handle_IEND(png_ptr, info_ptr, length);
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      else if (png_handle_as_unknown(png_ptr, chunk_name))
+      else if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
+         PNG_HANDLE_CHUNK_AS_DEFAULT)
       {
-         if (!png_memcmp(chunk_name, png_IDAT, 4))
+         if (chunk_name == png_IDAT)
          {
             if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
                png_benign_error(png_ptr, "Too many IDATs found");
          }
          png_handle_unknown(png_ptr, info_ptr, length);
-         if (!png_memcmp(chunk_name, png_PLTE, 4))
+         if (chunk_name == png_PLTE)
             png_ptr->mode |= PNG_HAVE_PLTE;
       }
 #endif
 
-      else if (!png_memcmp(chunk_name, png_IDAT, 4))
+      else if (chunk_name == png_IDAT)
       {
          /* Zero length IDATs are legal after the last IDAT has been
           * read, but not after other chunks have been read.
@@ -987,91 +864,91 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
 
          png_crc_finish(png_ptr, length);
       }
-      else if (!png_memcmp(chunk_name, png_PLTE, 4))
+      else if (chunk_name == png_PLTE)
          png_handle_PLTE(png_ptr, info_ptr, length);
 
 #ifdef PNG_READ_bKGD_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_bKGD, 4))
+      else if (chunk_name == png_bKGD)
          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_cHRM_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_cHRM, 4))
+      else if (chunk_name == png_cHRM)
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_gAMA_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_gAMA, 4))
+      else if (chunk_name == png_gAMA)
          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_hIST_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_hIST, 4))
+      else if (chunk_name == png_hIST)
          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_oFFs_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_oFFs, 4))
+      else if (chunk_name == png_oFFs)
          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_pCAL_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_pCAL, 4))
+      else if (chunk_name == png_pCAL)
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sCAL_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sCAL, 4))
+      else if (chunk_name == png_sCAL)
          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_pHYs_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_pHYs, 4))
+      else if (chunk_name == png_pHYs)
          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sBIT_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sBIT, 4))
+      else if (chunk_name == png_sBIT)
          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sRGB_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sRGB, 4))
+      else if (chunk_name == png_sRGB)
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_iCCP_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_iCCP, 4))
+      else if (chunk_name == png_iCCP)
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_sPLT_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_sPLT, 4))
+      else if (chunk_name == png_sPLT)
          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tEXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tEXt, 4))
+      else if (chunk_name == png_tEXt)
          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tIME_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tIME, 4))
+      else if (chunk_name == png_tIME)
          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_tRNS_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_tRNS, 4))
+      else if (chunk_name == png_tRNS)
          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_zTXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_zTXt, 4))
+      else if (chunk_name == png_zTXt)
          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 
 #ifdef PNG_READ_iTXt_SUPPORTED
-      else if (!png_memcmp(chunk_name, png_iTXt, 4))
+      else if (chunk_name == png_iTXt)
          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
 
@@ -1163,7 +1040,9 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    jmp_buf tmp_jmp;
 #endif
    png_error_ptr error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_error_ptr warning_fn;
+#endif
    png_voidp error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_free_ptr free_fn;
@@ -1249,10 +1128,6 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
 #endif
 #endif
 
-#ifdef PNG_TIME_RFC1123_SUPPORTED
-   png_free(png_ptr, png_ptr->time_buffer);
-#endif
-
    inflateEnd(&png_ptr->zstream);
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
@@ -1269,11 +1144,13 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
     * being used again.
     */
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
 #endif
 
    error_fn = png_ptr->error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    warning_fn = png_ptr->warning_fn;
+#endif
    error_ptr = png_ptr->error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    free_fn = png_ptr->free_fn;
@@ -1282,14 +1159,16 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    png_memset(png_ptr, 0, png_sizeof(png_struct));
 
    png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_ptr->warning_fn = warning_fn;
+#endif
    png_ptr->error_ptr = error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_ptr->free_fn = free_fn;
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+   png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
 #endif
 
 }
@@ -1325,8 +1204,22 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 
    /* -------------- image transformations start here ------------------- */
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-   /* Tell libpng to strip 16 bit/color files down to 8 bits per color.
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+   /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
+    */
+   if (transforms & PNG_TRANSFORM_SCALE_16)
+   {
+     /* Added at libpng-1.5.4. "strip_16" produces the same result that it
+      * did in earlier versions, while "scale_16" is now more accurate.
+      */
+      png_set_scale_16(png_ptr);
+   }
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+   /* If both SCALE and STRIP are required pngrtran will effectively cancel the
+    * latter by doing SCALE first.  This is ok and allows apps not to check for
+    * which is supported to get the right answer.
     */
    if (transforms & PNG_TRANSFORM_STRIP_16)
       png_set_strip_16(png_ptr);
@@ -1407,7 +1300,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 #endif
 
 #ifdef PNG_READ_SWAP_SUPPORTED
-   /* Swap bytes of 16 bit files to least significant byte first */
+   /* Swap bytes of 16-bit files to least significant byte first */
    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
       png_set_swap(png_ptr);
 #endif
@@ -1426,6 +1319,12 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
       png_set_gray_to_rgb(png_ptr);
 #endif
 
+/* Added at libpng-1.5.4 */
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   if (transforms & PNG_TRANSFORM_EXPAND_16)
+      png_set_expand_16(png_ptr);
+#endif
+
    /* We don't handle adding filler bytes */
 
    /* We use png_read_image and rely on that for interlace handling, but we also

pngrutil.c

@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.5.3 [(PENDING RELEASE)]
+ * Last changed in libpng 1.5.6 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 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.)
@@ -87,10 +87,10 @@ png_int_32 (PNGAPI
 png_get_int_32)(png_const_bytep buf)
 {
    png_uint_32 uval = png_get_uint_32(buf);
-   if ((uval & 0x80000000L) == 0) /* non-negative */
+   if ((uval & 0x80000000) == 0) /* non-negative */
       return uval;
 
-   uval = (uval ^ 0xffffffffL) + 1;  /* 2's complement: -x = ~x+1 */
+   uval = (uval ^ 0xffffffff) + 1;  /* 2's complement: -x = ~x+1 */
    return -(png_int_32)uval;
 }
 
@@ -165,14 +165,14 @@ png_read_chunk_header(png_structp png_ptr)
    length = png_get_uint_31(png_ptr, buf);
 
    /* Put the chunk name into png_ptr->chunk_name. */
-   png_memcpy(png_ptr->chunk_name, buf + 4, 4);
+   png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
 
-   png_debug2(0, "Reading %s chunk, length = %u",
-       png_ptr->chunk_name, length);
+   png_debug2(0, "Reading %lx chunk, length = %lu",
+       (unsigned long)png_ptr->chunk_name, (unsigned long)length);
 
    /* Reset the crc and run it over the chunk name. */
    png_reset_crc(png_ptr);
-   png_calculate_crc(png_ptr, png_ptr->chunk_name, 4);
+   png_calculate_crc(png_ptr, buf + 4, 4);
 
    /* Check to see if chunk name is valid. */
    png_check_chunk_name(png_ptr, png_ptr->chunk_name);
@@ -218,10 +218,9 @@ png_crc_finish(png_structp png_ptr, png_uint_32 skip)
 
    if (png_crc_error(png_ptr))
    {
-      if (((png_ptr->chunk_name[0] & 0x20) &&                /* Ancillary */
-          !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
-          (!(png_ptr->chunk_name[0] & 0x20) &&             /* Critical  */
-          (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)))
+      if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name) ?
+          !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) :
+          (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))
       {
          png_chunk_warning(png_ptr, "CRC error");
       }
@@ -248,14 +247,14 @@ png_crc_error(png_structp png_ptr)
    png_uint_32 crc;
    int need_crc = 1;
 
-   if (png_ptr->chunk_name[0] & 0x20)                     /* ancillary */
+   if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name))
    {
       if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
           (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
          need_crc = 0;
    }
 
-   else                                                    /* critical */
+   else /* critical */
    {
       if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
          need_crc = 0;
@@ -369,41 +368,31 @@ png_inflate(png_structp png_ptr, png_bytep data, png_size_t size,
        * and the error message is dumped into the uncompressed
        * buffer if available.
        */
+#     ifdef PNG_WARNINGS_SUPPORTED
       {
-         PNG_CONST char *msg;
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         char umsg[52];
-#endif
+         png_const_charp msg;
+
          if (png_ptr->zstream.msg != 0)
             msg = png_ptr->zstream.msg;
 
-         else
+         else switch (ret)
          {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-            switch (ret)
-            {
-               case Z_BUF_ERROR:
-                  msg = "Buffer error in compressed datastream in %s chunk";
-                  break;
+            case Z_BUF_ERROR:
+               msg = "Buffer error in compressed datastream";
+               break;
 
-               case Z_DATA_ERROR:
-                  msg = "Data error in compressed datastream in %s chunk";
-                  break;
+            case Z_DATA_ERROR:
+               msg = "Data error in compressed datastream";
+               break;
 
-               default:
-                  msg = "Incomplete compressed datastream in %s chunk";
-                  break;
-            }
-
-            png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name);
-            msg = umsg;
-#else
-            msg = "Damaged compressed datastream in chunk other than IDAT";
-#endif
+            default:
+               msg = "Incomplete compressed datastream";
+               break;
          }
 
-         png_warning(png_ptr, msg);
+         png_chunk_warning(png_ptr, msg);
       }
+#     endif
 
       /* 0 means an error - notice that this code simply ignores
        * zero length compressed chunks as a result.
@@ -437,8 +426,8 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
       png_size_t expanded_size = png_inflate(png_ptr,
           (png_bytep)(png_ptr->chunkdata + prefix_size),
           chunklength - prefix_size,
-          0,            /*output*/
-          0);           /*output size*/
+          0,            /* output */
+          0);           /* output size */
 
       /* Now check the limits on this chunk - if the limit fails the
        * compressed data will be removed, the prefix will remain.
@@ -468,7 +457,7 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
       {
          /* Success (maybe) - really uncompress the chunk. */
          png_size_t new_size = 0;
-         png_charp text = png_malloc_warn(png_ptr,
+         png_charp text = (png_charp)png_malloc_warn(png_ptr,
              prefix_size + expanded_size + 1);
 
          if (text != NULL)
@@ -499,15 +488,9 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
 
    else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
    {
-#ifdef PNG_STDIO_SUPPORTED
-      char umsg[50];
-
-      png_snprintf(umsg, sizeof umsg,
-          "Unknown zTXt compression type %d", comp_type);
-      png_warning(png_ptr, umsg);
-#else
-      png_warning(png_ptr, "Unknown zTXt compression type");
-#endif
+      PNG_WARNING_PARAMETERS(p)
+      png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type);
+      png_formatted_warning(png_ptr, p, "Unknown zTXt compression type @1");
 
       /* The recovery is to simply drop the data. */
    }
@@ -517,7 +500,7 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
     * amount of compressed data.
     */
    {
-      png_charp text = png_malloc_warn(png_ptr, prefix_size + 1);
+      png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + 1);
 
       if (text != NULL)
       {
@@ -843,14 +826,12 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 #  ifdef PNG_READ_sRGB_SUPPORTED
    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
    {
-      if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
+      if (PNG_OUT_OF_RANGE(igamma, 45500, 500))
       {
-         png_warning(png_ptr,
-             "Ignoring incorrect gAMA value when sRGB is also present");
-
-#    ifdef PNG_CONSOLE_IO_SUPPORTED
-         fprintf(stderr, "gamma = (%d/100000)", (int)igamma);
-#    endif
+         PNG_WARNING_PARAMETERS(p)
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, igamma);
+         png_formatted_warning(png_ptr, p,
+             "Ignoring incorrect gAMA value @1 when sRGB is also present");
          return;
       }
    }
@@ -1012,28 +993,112 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    {
       if (PNG_OUT_OF_RANGE(x_white, 31270,  1000) ||
           PNG_OUT_OF_RANGE(y_white, 32900,  1000) ||
-          PNG_OUT_OF_RANGE(x_red,   64000L, 1000) ||
+          PNG_OUT_OF_RANGE(x_red,   64000,  1000) ||
           PNG_OUT_OF_RANGE(y_red,   33000,  1000) ||
           PNG_OUT_OF_RANGE(x_green, 30000,  1000) ||
-          PNG_OUT_OF_RANGE(y_green, 60000L, 1000) ||
+          PNG_OUT_OF_RANGE(y_green, 60000,  1000) ||
           PNG_OUT_OF_RANGE(x_blue,  15000,  1000) ||
           PNG_OUT_OF_RANGE(y_blue,   6000,  1000))
       {
-         png_warning(png_ptr,
-             "Ignoring incorrect cHRM value when sRGB is also present");
+         PNG_WARNING_PARAMETERS(p)
 
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         fprintf(stderr, "wx=%d, wy=%d, rx=%d, ry=%d\n",
-             x_white, y_white, x_red, y_red);
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, x_white);
+         png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_fixed, y_white);
+         png_warning_parameter_signed(p, 3, PNG_NUMBER_FORMAT_fixed, x_red);
+         png_warning_parameter_signed(p, 4, PNG_NUMBER_FORMAT_fixed, y_red);
+         png_warning_parameter_signed(p, 5, PNG_NUMBER_FORMAT_fixed, x_green);
+         png_warning_parameter_signed(p, 6, PNG_NUMBER_FORMAT_fixed, y_green);
+         png_warning_parameter_signed(p, 7, PNG_NUMBER_FORMAT_fixed, x_blue);
+         png_warning_parameter_signed(p, 8, PNG_NUMBER_FORMAT_fixed, y_blue);
 
-         fprintf(stderr, "gx=%d, gy=%d, bx=%d, by=%d\n",
-             x_green, y_green, x_blue, y_blue);
-#endif /* PNG_CONSOLE_IO_SUPPORTED */
+         png_formatted_warning(png_ptr, p,
+             "Ignoring incorrect cHRM white(@1,@2) r(@3,@4)g(@5,@6)b(@7,@8) "
+             "when sRGB is also present");
       }
       return;
    }
 #endif /* PNG_READ_sRGB_SUPPORTED */
 
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   /* Store the _white values as default coefficients for the rgb to gray
+    * operation if it is supported.  Check if the transform is already set to
+    * avoid destroying the transform values.
+    */
+   if (!png_ptr->rgb_to_gray_coefficients_set)
+   {
+      /* png_set_background has not been called and we haven't seen an sRGB
+       * chunk yet.  Find the XYZ of the three end points.
+       */
+      png_XYZ XYZ;
+      png_xy xy;
+
+      xy.redx = x_red;
+      xy.redy = y_red;
+      xy.greenx = x_green;
+      xy.greeny = y_green;
+      xy.bluex = x_blue;
+      xy.bluey = y_blue;
+      xy.whitex = x_white;
+      xy.whitey = y_white;
+
+      if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy))
+      {
+         /* The success case, because XYZ_from_xy normalises to a reference
+          * white Y of 1.0 we just need to scale the numbers.  This should
+          * always work just fine. It is an internal error if this overflows.
+          */
+         {
+            png_fixed_point r, g, b;
+            if (png_muldiv(&r, XYZ.redY, 32768, PNG_FP_1) &&
+               r >= 0 && r <= 32768 &&
+               png_muldiv(&g, XYZ.greenY, 32768, PNG_FP_1) &&
+               g >= 0 && g <= 32768 &&
+               png_muldiv(&b, XYZ.blueY, 32768, PNG_FP_1) &&
+               b >= 0 && b <= 32768 &&
+               r+g+b <= 32769)
+            {
+               /* We allow 0 coefficients here.  r+g+b may be 32769 if two or
+                * all of the coefficients were rounded up.  Handle this by
+                * reducing the *largest* coefficient by 1; this matches the
+                * approach used for the default coefficients in pngrtran.c
+                */
+               int add = 0;
+
+               if (r+g+b > 32768)
+                  add = -1;
+               else if (r+g+b < 32768)
+                  add = 1;
+
+               if (add != 0)
+               {
+                  if (g >= r && g >= b)
+                     g += add;
+                  else if (r >= g && r >= b)
+                     r += add;
+                  else
+                     b += add;
+               }
+
+               /* Check for an internal error. */
+               if (r+g+b != 32768)
+                  png_error(png_ptr,
+                     "internal error handling cHRM coefficients");
+
+               png_ptr->rgb_to_gray_red_coeff   = (png_uint_16)r;
+               png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g;
+            }
+
+            /* This is a png_error at present even though it could be ignored -
+             * it should never happen, but it is important that if it does, the
+             * bug is fixed.
+             */
+            else
+               png_error(png_ptr, "internal error handling cHRM->XYZ");
+         }
+      }
+   }
+#endif
+
    png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red,
       x_green, y_green, x_blue, y_blue);
 }
@@ -1093,13 +1158,15 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
    {
-      if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500L, 500))
+      if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500, 500))
       {
-         png_warning(png_ptr,
-             "Ignoring incorrect gAMA value when sRGB is also present");
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         fprintf(stderr, "incorrect gamma=(%d/100000)\n", info_ptr->gamma);
-#endif
+         PNG_WARNING_PARAMETERS(p)
+
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed,
+            info_ptr->gamma);
+
+         png_formatted_warning(png_ptr, p,
+             "Ignoring incorrect gAMA value @1 when sRGB is also present");
       }
    }
 #endif /* PNG_READ_gAMA_SUPPORTED */
@@ -1108,10 +1175,10 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
       if (PNG_OUT_OF_RANGE(info_ptr->x_white, 31270,  1000) ||
           PNG_OUT_OF_RANGE(info_ptr->y_white, 32900,  1000) ||
-          PNG_OUT_OF_RANGE(info_ptr->x_red,   64000L, 1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->x_red,   64000,  1000) ||
           PNG_OUT_OF_RANGE(info_ptr->y_red,   33000,  1000) ||
           PNG_OUT_OF_RANGE(info_ptr->x_green, 30000,  1000) ||
-          PNG_OUT_OF_RANGE(info_ptr->y_green, 60000L, 1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->y_green, 60000,  1000) ||
           PNG_OUT_OF_RANGE(info_ptr->x_blue,  15000,  1000) ||
           PNG_OUT_OF_RANGE(info_ptr->y_blue,   6000,  1000))
       {
@@ -1120,6 +1187,47 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       }
 #endif /* PNG_READ_cHRM_SUPPORTED */
 
+   /* This is recorded for use when handling the cHRM chunk above.  An sRGB
+    * chunk unconditionally overwrites the coefficients for grayscale conversion
+    * too.
+    */
+   png_ptr->is_sRGB = 1;
+
+#  ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+      /* Don't overwrite user supplied values: */
+      if (!png_ptr->rgb_to_gray_coefficients_set)
+      {
+         /* These numbers come from the sRGB specification (or, since one has to
+          * pay much money to get a copy, the wikipedia sRGB page) the
+          * chromaticity values quoted have been inverted to get the reverse
+          * transformation from RGB to XYZ and the 'Y' coefficients scaled by
+          * 32768 (then rounded).
+          *
+          * sRGB and ITU Rec-709 both truncate the values for the D65 white
+          * point to four digits and, even though it actually stores five
+          * digits, the PNG spec gives the truncated value.
+          *
+          * This means that when the chromaticities are converted back to XYZ
+          * end points we end up with (6968,23435,2366), which, as described in
+          * pngrtran.c, would overflow.  If the five digit precision and up is
+          * used we get, instead:
+          *
+          *    6968*R + 23435*G + 2365*B
+          *
+          * (Notice that this rounds the blue coefficient down, rather than the
+          * choice used in pngrtran.c which is to round the green one down.)
+          */
+         png_ptr->rgb_to_gray_red_coeff   =  6968; /* 0.212639005871510 */
+         png_ptr->rgb_to_gray_green_coeff = 23434; /* 0.715168678767756 */
+         /* png_ptr->rgb_to_gray_blue_coeff  =  2366; 0.072192315360734	*/
+
+         /* The following keeps the cHRM chunk from destroying the
+          * coefficients again in the event that it follows the sRGB chunk.
+          */
+         png_ptr->rgb_to_gray_coefficients_set = 1;
+      }
+#  endif
+
    png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
 }
 #endif /* PNG_READ_sRGB_SUPPORTED */
@@ -1239,23 +1347,15 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    /* And the following guarantees that profile_size == profile_length. */
    if (profile_size > profile_length)
    {
+      PNG_WARNING_PARAMETERS(p)
+
       png_free(png_ptr, png_ptr->chunkdata);
       png_ptr->chunkdata = NULL;
-#ifdef PNG_STDIO_SUPPORTED
-      {
-         char umsg[80];
 
-         png_snprintf2(umsg, 80,
-             "Ignoring iCCP chunk with declared size = %u "
-              "and actual length = %u",
-              (unsigned int) profile_size,
-              (unsigned int) profile_length);
-         png_warning(png_ptr, umsg);
-      }
-#else
-      png_warning(png_ptr,
-         "Ignoring iCCP chunk with uncompressed size mismatch");
-#endif
+      png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_u, profile_size);
+      png_warning_parameter_unsigned(p, 2, PNG_NUMBER_FORMAT_u, profile_length);
+      png_formatted_warning(png_ptr, p,
+         "Ignoring iCCP chunk with declared size = @1 and actual length = @2");
       return;
    }
 
@@ -1564,6 +1664,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_size_t truelen;
    png_byte buf[6];
+   png_color_16 background;
 
    png_debug(1, "in png_handle_bKGD");
 
@@ -1620,7 +1721,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
     */
    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
    {
-      png_ptr->background.index = buf[0];
+      background.index = buf[0];
 
       if (info_ptr && info_ptr->num_palette)
       {
@@ -1630,33 +1731,36 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
             return;
          }
 
-         png_ptr->background.red =
-             (png_uint_16)png_ptr->palette[buf[0]].red;
-
-         png_ptr->background.green =
-             (png_uint_16)png_ptr->palette[buf[0]].green;
-
-         png_ptr->background.blue =
-             (png_uint_16)png_ptr->palette[buf[0]].blue;
+         background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
+         background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
+         background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
       }
+
+      else
+         background.red = background.green = background.blue = 0;
+
+      background.gray = 0;
    }
 
    else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
    {
-      png_ptr->background.red =
-      png_ptr->background.green =
-      png_ptr->background.blue =
-      png_ptr->background.gray = png_get_uint_16(buf);
+      background.index = 0;
+      background.red =
+      background.green =
+      background.blue =
+      background.gray = png_get_uint_16(buf);
    }
 
    else
    {
-      png_ptr->background.red = png_get_uint_16(buf);
-      png_ptr->background.green = png_get_uint_16(buf + 2);
-      png_ptr->background.blue = png_get_uint_16(buf + 4);
+      background.index = 0;
+      background.red = png_get_uint_16(buf);
+      background.green = png_get_uint_16(buf + 2);
+      background.blue = png_get_uint_16(buf + 4);
+      background.gray = 0;
    }
 
-   png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background));
+   png_set_bKGD(png_ptr, info_ptr, &background);
 }
 #endif
 
@@ -1981,6 +2085,14 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       return;
    }
 
+   /* Need unit type, width, \0, height: minimum 4 bytes */
+   else if (length < 4)
+   {
+      png_warning(png_ptr, "sCAL chunk too short");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+
    png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
       length + 1);
 
@@ -2016,23 +2128,29 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    /* Validate the ASCII numbers, need two ASCII numbers separated by
     * a '\0' and they need to fit exactly in the chunk data.
     */
-   i = 0;
+   i = 1;
    state = 0;
 
-   if (png_ptr->chunkdata[1] == 45 /* negative width */ ||
-       !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+   if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
        i >= slength || png_ptr->chunkdata[i++] != 0)
       png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format");
 
+   else if (!PNG_FP_IS_POSITIVE(state))
+      png_warning(png_ptr, "Invalid sCAL chunk ignored: non-positive width");
+
    else
    {
       png_size_t heighti = i;
 
-      if (png_ptr->chunkdata[i] == 45 /* negative height */ ||
-          !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+      state = 0;
+      if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
           i != slength)
          png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format");
 
+      else if (!PNG_FP_IS_POSITIVE(state))
+         png_warning(png_ptr,
+            "Invalid sCAL chunk ignored: non-positive height");
+
       else
          /* This is the (only) success case. */
          png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0],
@@ -2522,16 +2640,14 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
    if (png_ptr->mode & PNG_HAVE_IDAT)
    {
-      PNG_IDAT;
-
-      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))  /* Not an IDAT */
+      if (png_ptr->chunk_name != png_IDAT)
          png_ptr->mode |= PNG_AFTER_IDAT;
    }
 
-   if (!(png_ptr->chunk_name[0] & 0x20))
+   if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
    {
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+      if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
           PNG_HANDLE_CHUNK_ALWAYS
 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
           && png_ptr->read_user_chunk_fn == NULL
@@ -2549,21 +2665,20 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
        )
    {
 #ifdef PNG_MAX_MALLOC_64K
-      if (length > (png_uint_32)65535L)
+      if (length > 65535)
       {
          png_warning(png_ptr, "unknown chunk too large to fit in memory");
-         skip = length - (png_uint_32)65535L;
-         length = (png_uint_32)65535L;
+         skip = length - 65535;
+         length = 65535;
       }
 #endif
 
-      png_memcpy((png_charp)png_ptr->unknown_chunk.name,
-          (png_charp)png_ptr->chunk_name,
-          png_sizeof(png_ptr->unknown_chunk.name));
-
-      png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1]
-          = '\0';
-
+      /* TODO: this code is very close to the unknown handling in pngpread.c,
+       * maybe it can be put into a common utility routine?
+       * png_struct::unknown_chunk is just used as a temporary variable, along
+       * with the data into which the chunk is read.  These can be eliminated.
+       */
+      PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
       png_ptr->unknown_chunk.size = (png_size_t)length;
 
       if (length == 0)
@@ -2572,7 +2687,7 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       else
       {
          png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
-         png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
+         png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
       }
 
 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
@@ -2589,10 +2704,10 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
          if (ret == 0)
          {
-            if (!(png_ptr->chunk_name[0] & 0x20))
+            if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
             {
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-               if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+               if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
                    PNG_HANDLE_CHUNK_ALWAYS)
 #endif
                   png_chunk_error(png_ptr, "unknown critical chunk");
@@ -2629,16 +2744,26 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
  * the chunk name itself is valid.
  */
 
-#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is:
+ *
+ * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+ */
 
 void /* PRIVATE */
-png_check_chunk_name(png_structp png_ptr, png_const_bytep chunk_name)
+png_check_chunk_name(png_structp png_ptr, png_uint_32 chunk_name)
 {
+   int i;
+
    png_debug(1, "in png_check_chunk_name");
-   if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
-       isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
+
+   for (i=1; i<=4; ++i)
    {
-      png_chunk_error(png_ptr, "invalid chunk type");
+      int c = chunk_name & 0xff;
+
+      if (c < 65 || c > 122 || (c > 90 && c < 97))
+         png_chunk_error(png_ptr, "invalid chunk type");
+
+      chunk_name >>= 8;
    }
 }
 
@@ -2657,17 +2782,33 @@ png_check_chunk_name(png_structp png_ptr, png_const_bytep chunk_name)
 void /* PRIVATE */
 png_combine_row(png_structp png_ptr, png_bytep row, int mask)
 {
+   int pixel_depth = png_ptr->transformed_pixel_depth;
+
    png_debug(1, "in png_combine_row");
 
+   /* Added in 1.5.6: it should not be possible to enter this routine until at
+    * least one row has been read from the PNG data and transformed.
+    */
+   if (pixel_depth == 0)
+      png_error(png_ptr, "internal row logic error");
+
+   /* Added in 1.5.4: the pixel depth should match the information returned by
+    * any call to png_read_update_info at this point.  Do not continue if we got
+    * this wrong.
+    */
+   if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
+          PNG_ROWBYTES(pixel_depth, png_ptr->width))
+      png_error(png_ptr, "internal row size calculation error");
+
    if (mask == 0xff)
    {
       png_memcpy(row, png_ptr->row_buf + 1,
-          PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
+          PNG_ROWBYTES(pixel_depth, png_ptr->width));
    }
 
    else
    {
-      switch (png_ptr->row_info.pixel_depth)
+      switch (pixel_depth)
       {
          case 1:
          {
@@ -2844,7 +2985,7 @@ png_combine_row(png_structp png_ptr, png_bytep row, int mask)
          {
             png_bytep sp = png_ptr->row_buf + 1;
             png_bytep dp = row;
-            png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+            png_size_t pixel_bytes = pixel_depth >> 3;
             png_uint_32 i;
             png_uint_32 row_width = png_ptr->width;
             png_byte m = 0x80;
@@ -2873,15 +3014,12 @@ png_combine_row(png_structp png_ptr, png_bytep row, int mask)
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
 void /* PRIVATE */
-png_do_read_interlace(png_structp png_ptr)
+png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+   png_uint_32 transformations /* Because these may affect the byte layout */)
 {
-   png_row_infop row_info = &(png_ptr->row_info);
-   png_bytep row = png_ptr->row_buf + 1;
-   int pass = png_ptr->pass;
-   png_uint_32 transformations = png_ptr->transformations;
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
    /* Offset to next interlace block */
-   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
 
    png_debug(1, "in png_do_read_interlace");
    if (row != NULL && row_info != NULL)
@@ -3114,12 +3252,13 @@ png_do_read_interlace(png_structp png_ptr)
 }
 #endif /* PNG_READ_INTERLACING_SUPPORTED */
 
+/* 1.5.6: Changed to just take a png_row_info (not png_ptr) and to ignore bad
+ * adaptive filter bytes.
+ */
 void /* PRIVATE */
-png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
-    png_const_bytep prev_row, int filter)
+png_read_filter_row(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row, int filter)
 {
-   png_debug(1, "in png_read_filter_row");
-   png_debug2(2, "row = %u, filter = %d", png_ptr->row_number, filter);
    switch (filter)
    {
       case PNG_FILTER_VALUE_NONE:
@@ -3236,8 +3375,7 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
          break;
       }
       default:
-         png_error(png_ptr, "Ignoring bad adaptive filter type");
-         /*NOT REACHED */
+         /* NOT REACHED */
          break;
    }
 }
@@ -3250,16 +3388,16 @@ png_read_finish_row(png_structp png_ptr)
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
-   PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
 
    /* Offset to next interlace block */
-   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
 
    /* Start of interlace block in the y direction */
-   PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
 
    /* Offset to next interlace block in the y direction */
-   PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
 #endif /* PNG_READ_INTERLACING_SUPPORTED */
 
    png_debug(1, "in png_read_finish_row");
@@ -3306,7 +3444,6 @@ png_read_finish_row(png_structp png_ptr)
 
    if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
    {
-      PNG_IDAT;
       char extra;
       int ret;
 
@@ -3321,7 +3458,7 @@ png_read_finish_row(png_structp png_ptr)
             {
                png_crc_finish(png_ptr, 0);
                png_ptr->idat_size = png_read_chunk_header(png_ptr);
-               if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+               if (png_ptr->chunk_name != png_IDAT)
                   png_error(png_ptr, "Not enough image data");
             }
 
@@ -3380,16 +3517,16 @@ png_read_start_row(png_structp png_ptr)
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
-   PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
 
    /* Offset to next interlace block */
-   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
 
    /* Start of interlace block in the y direction */
-   PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
 
    /* Offset to next interlace block in the y direction */
-   PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
 #endif
 
    int max_pixel_depth;
@@ -3397,7 +3534,9 @@ png_read_start_row(png_structp png_ptr)
 
    png_debug(1, "in png_read_start_row");
    png_ptr->zstream.avail_in = 0;
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
    png_init_read_transformations(png_ptr);
+#endif
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    if (png_ptr->interlaced)
    {
@@ -3547,14 +3686,20 @@ png_read_start_row(png_structp png_ptr)
 defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
    if (png_ptr->transformations & PNG_USER_TRANSFORM)
    {
-      int user_pixel_depth = png_ptr->user_transform_depth*
+      int user_pixel_depth = png_ptr->user_transform_depth *
          png_ptr->user_transform_channels;
 
       if (user_pixel_depth > max_pixel_depth)
-         max_pixel_depth=user_pixel_depth;
+         max_pixel_depth = user_pixel_depth;
    }
 #endif
 
+   /* This value is stored in png_struct and double checked in the row read
+    * code.
+    */
+   png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
+   png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
+
    /* Align the width on the next larger 8 pixels.  Mainly used
     * for interlacing
     */

pngset.c

@@ -1,7 +1,7 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Last changed in libpng 1.5.6 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 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.)
@@ -64,6 +64,39 @@ png_set_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
    }
 }
 
+void PNGFAPI
+png_set_cHRM_XYZ_fixed(png_structp png_ptr, png_infop info_ptr,
+    png_fixed_point int_red_X, png_fixed_point int_red_Y,
+    png_fixed_point int_red_Z, png_fixed_point int_green_X,
+    png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+    png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+    png_fixed_point int_blue_Z)
+{
+   png_XYZ XYZ;
+   png_xy xy;
+
+   png_debug1(1, "in %s storage function", "cHRM XYZ fixed");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   XYZ.redX = int_red_X;
+   XYZ.redY = int_red_Y;
+   XYZ.redZ = int_red_Z;
+   XYZ.greenX = int_green_X;
+   XYZ.greenY = int_green_Y;
+   XYZ.greenZ = int_green_Z;
+   XYZ.blueX = int_blue_X;
+   XYZ.blueY = int_blue_Y;
+   XYZ.blueZ = int_blue_Z;
+
+   if (png_xy_from_XYZ(&xy, XYZ))
+      png_error(png_ptr, "XYZ values out of representable range");
+
+   png_set_cHRM_fixed(png_ptr, info_ptr, xy.whitex, xy.whitey, xy.redx, xy.redy,
+      xy.greenx, xy.greeny, xy.bluex, xy.bluey);
+}
+
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 void PNGAPI
 png_set_cHRM(png_structp png_ptr, png_infop info_ptr,
@@ -80,6 +113,23 @@ png_set_cHRM(png_structp png_ptr, png_infop info_ptr,
       png_fixed(png_ptr, blue_x, "cHRM Blue X"),
       png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
 }
+
+void PNGAPI
+png_set_cHRM_XYZ(png_structp png_ptr, png_infop info_ptr, double red_X,
+    double red_Y, double red_Z, double green_X, double green_Y, double green_Z,
+    double blue_X, double blue_Y, double blue_Z)
+{
+   png_set_cHRM_XYZ_fixed(png_ptr, info_ptr,
+      png_fixed(png_ptr, red_X, "cHRM Red X"),
+      png_fixed(png_ptr, red_Y, "cHRM Red Y"),
+      png_fixed(png_ptr, red_Z, "cHRM Red Z"),
+      png_fixed(png_ptr, green_X, "cHRM Red X"),
+      png_fixed(png_ptr, green_Y, "cHRM Red Y"),
+      png_fixed(png_ptr, green_Z, "cHRM Red Z"),
+      png_fixed(png_ptr, blue_X, "cHRM Red X"),
+      png_fixed(png_ptr, blue_Y, "cHRM Red Y"),
+      png_fixed(png_ptr, blue_Z, "cHRM Red Z"));
+}
 #  endif /* PNG_FLOATING_POINT_SUPPORTED */
 
 #endif /* PNG_cHRM_SUPPORTED */
@@ -94,15 +144,16 @@ png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   /* Previously these values were limited, however they must be
-    * wrong, therefore storing them (and setting PNG_INFO_gAMA)
-    * must be wrong too.
+   /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't
+    * occur.  Since the fixed point representation is assymetrical it is
+    * possible for 1/gamma to overflow the limit of 21474 and this means the
+    * gamma value must be at least 5/100000 and hence at most 20000.0.  For
+    * safety the limits here are a little narrower.  The values are 0.00016 to
+    * 6250.0, which are truly ridiculous gammma values (and will produce
+    * displays that are all black or all white.)
     */
-   if (file_gamma > (png_fixed_point)PNG_UINT_31_MAX)
-      png_warning(png_ptr, "Gamma too large, ignored");
-
-   else if (file_gamma <= 0)
-      png_warning(png_ptr, "Negative or zero gamma ignored");
+   if (file_gamma < 16 || file_gamma > 625000000)
+      png_warning(png_ptr, "Out of range gamma value ignored");
 
    else
    {
@@ -340,12 +391,12 @@ png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
    if (unit != 1 && unit != 2)
       png_error(png_ptr, "Invalid sCAL unit");
 
-   if (swidth == NULL || (lengthw = png_strlen(swidth)) <= 0 ||
-       swidth[0] == 45 /*'-'*/ || !png_check_fp_string(swidth, lengthw))
+   if (swidth == NULL || (lengthw = png_strlen(swidth)) == 0 ||
+       swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
       png_error(png_ptr, "Invalid sCAL width");
 
-   if (sheight == NULL || (lengthh = png_strlen(sheight)) <= 0 ||
-       sheight[0] == 45 /*'-'*/ || !png_check_fp_string(sheight, lengthh))
+   if (sheight == NULL || (lengthh = png_strlen(sheight)) == 0 ||
+       sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
       png_error(png_ptr, "Invalid sCAL height");
 
    info_ptr->scal_unit = (png_byte)unit;
@@ -545,16 +596,16 @@ png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
    png_set_sRGB(png_ptr, info_ptr, srgb_intent);
 
 #  ifdef PNG_gAMA_SUPPORTED
-   png_set_gAMA_fixed(png_ptr, info_ptr, 45455L);
+   png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
 #  endif
 
 #  ifdef PNG_cHRM_SUPPORTED
    png_set_cHRM_fixed(png_ptr, info_ptr,
       /* color      x       y */
-      /* white */ 31270L, 32900L,
-      /* red   */ 64000L, 33000L,
-      /* green */ 30000L, 60000L,
-      /* blue  */ 15000L,  6000L
+      /* white */ 31270, 32900,
+      /* red   */ 64000, 33000,
+      /* green */ 30000, 60000,
+      /* blue  */ 15000,  6000
    );
 #  endif /* cHRM */
 }
@@ -569,7 +620,7 @@ png_set_iCCP(png_structp png_ptr, png_infop info_ptr,
 {
    png_charp new_iccp_name;
    png_bytep new_iccp_profile;
-   png_uint_32 length;
+   png_size_t length;
 
    png_debug1(1, "in %s storage function", "iCCP");
 
@@ -630,9 +681,8 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr,
 {
    int i;
 
-   png_debug1(1, "in %s storage function", ((png_ptr == NULL ||
-       png_ptr->chunk_name[0] == '\0') ?
-       "text" : (png_const_charp)png_ptr->chunk_name));
+   png_debug1(1, "in %lx storage function", png_ptr == NULL ? "unexpected" :
+      (unsigned long)png_ptr->chunk_name);
 
    if (png_ptr == NULL || info_ptr == NULL || num_text == 0)
       return(0);
@@ -915,10 +965,10 @@ png_set_sPLT(png_structp png_ptr,
    {
       png_sPLT_tp to = np + info_ptr->splt_palettes_num + i;
       png_const_sPLT_tp from = entries + i;
-      png_uint_32 length;
+      png_size_t length;
 
       length = png_strlen(from->name) + 1;
-      to->name = (png_charp)png_malloc_warn(png_ptr, (png_size_t)length);
+      to->name = (png_charp)png_malloc_warn(png_ptr, length);
 
       if (to->name == NULL)
       {
@@ -929,7 +979,7 @@ png_set_sPLT(png_structp png_ptr,
 
       png_memcpy(to->name, from->name, length);
       to->entries = (png_sPLT_entryp)png_malloc_warn(png_ptr,
-          (png_size_t)(from->nentries * png_sizeof(png_sPLT_entry)));
+          from->nentries * png_sizeof(png_sPLT_entry));
 
       if (to->entries == NULL)
       {

pngstruct.h

@@ -5,7 +5,7 @@
  * (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 1.5.5 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -29,11 +29,13 @@
 struct png_struct_def
 {
 #ifdef PNG_SETJMP_SUPPORTED
-   jmp_buf png_jmpbuf;            /* used in png_error */
+   jmp_buf longjmp_buffer;    /* used in png_error */
    png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
 #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 */
@@ -64,21 +66,36 @@ struct png_struct_def
    z_stream zstream;          /* pointer to decompression structure (below) */
    png_bytep zbuf;            /* buffer for zlib */
    uInt zbuf_size;            /* size of zbuf (typically 65536) */
+#ifdef PNG_WRITE_SUPPORTED
+
+/* Added in 1.5.4: state to keep track of whether the zstream has been
+ * initialized and if so whether it is for IDAT or some other chunk.
+ */
+#define PNG_ZLIB_UNINITIALIZED 0
+#define PNG_ZLIB_FOR_IDAT      1
+#define PNG_ZLIB_FOR_TEXT      2 /* anything other than IDAT */
+#define PNG_ZLIB_USE_MASK      3 /* bottom two bits */
+#define PNG_ZLIB_IN_USE        4 /* a flag value */
+
+   png_uint_32 zlib_state;       /* State of zlib initialization */
+/* End of material added at libpng 1.5.4 */
+
    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 */
-/* Added at libpng 1.5.3 */
+#endif
+/* Added at libpng 1.5.4 */
 #if defined(PNG_WRITE_COMPRESSED_TEXT_SUPPORTED) || \
-    defined(PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION)
+    defined(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 1.5.3 */
+/* End of material added at libpng 1.5.4 */
 
    png_uint_32 width;         /* width of image in pixels */
    png_uint_32 height;        /* height of image in pixels */
@@ -87,20 +104,20 @@ struct png_struct_def
    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 */
    png_bytep row_buf;         /* buffer to save current (unfiltered) row */
    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 */
-   png_row_info row_info;     /* used for transformation routines */
+   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 */
    png_uint_16 num_trans;     /* number of transparency values */
-   png_byte chunk_name[5];    /* null-terminated name of current chunk */
    png_byte compression;      /* file compression type (always 0) */
    png_byte filter;           /* file filter type (always 0) */
    png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
@@ -108,17 +125,24 @@ struct png_struct_def
    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 */
+   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 */
+   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 */
+   png_byte io_chunk_string[5];
+                              /* string name of chunk */
 
 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
    png_uint_16 filler;           /* filler bytes for pixel expansion */
 #endif
 
-#ifdef PNG_bKGD_SUPPORTED
+#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 */
@@ -219,7 +243,7 @@ struct png_struct_def
 #endif
 
 #ifdef PNG_TIME_RFC1123_SUPPORTED
-   png_charp time_buffer; /* String to hold RFC 1123 time text */
+   char time_buffer[29]; /* String to hold RFC 1123 time text */
 #endif
 
 /* New members added in libpng-1.0.6 */
@@ -236,13 +260,20 @@ struct png_struct_def
    png_bytep chunk_list;
 #endif
 
+#ifdef PNG_READ_sRGB_SUPPORTED
+   /* Added in 1.5.5 to record an sRGB chunk in the png. */
+   png_byte is_sRGB;
+#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;
-   png_uint_16 rgb_to_gray_blue_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) */

pngtest.c

@@ -1,7 +1,7 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.5.3 [(PENDING RELEASE)]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 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.)
@@ -31,6 +31,8 @@
  * of files at once by typing "pngtest -m file1.png file2.png ..."
  */
 
+#define _POSIX_SOURCE 1
+
 #include "zlib.h"
 #include "png.h"
 /* Copied from pngpriv.h but only used in error messages below. */
@@ -779,7 +781,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    int bit_depth, color_type;
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
-   jmp_buf png_jmpbuf;
+   jmp_buf tmp_jmpbuf;
 #endif
 #endif
 
@@ -848,7 +850,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_SETJMP_SUPPORTED
    pngtest_debug("Setting jmpbuf for read struct");
 #ifdef USE_FAR_KEYWORD
-   if (setjmp(png_jmpbuf))
+   if (setjmp(tmp_jmpbuf))
 #else
    if (setjmp(png_jmpbuf(read_ptr)))
 #endif
@@ -866,14 +868,14 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       return (1);
    }
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(read_ptr), png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(read_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 #endif
 
 #ifdef PNG_WRITE_SUPPORTED
    pngtest_debug("Setting jmpbuf for write struct");
 #ifdef USE_FAR_KEYWORD
 
-   if (setjmp(png_jmpbuf))
+   if (setjmp(tmp_jmpbuf))
 #else
    if (setjmp(png_jmpbuf(write_ptr)))
 #endif
@@ -890,7 +892,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    }
 
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(write_ptr), png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(write_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 #endif
 #endif
 #endif
@@ -913,10 +915,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #  endif
 #endif
 
-#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION
+#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 1.5.3, and to test this new API.
+    * versions prior to 1.5.4, and to test this new API.
     */
    png_set_text_compression_strategy(write_ptr, Z_FILTERED);
 #endif
@@ -1792,4 +1794,4 @@ main(int argc, char *argv[])
 }
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_5_3beta02 Your_png_h_is_not_version_1_5_3beta02;
+typedef png_libpng_version_1_5_6beta02 Your_png_h_is_not_version_1_5_6beta02;

pngtrans.c

@@ -1,7 +1,7 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 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.)
@@ -442,7 +442,11 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
    /* At the start sp will point to the first byte to copy and dp to where
     * it is copied to.  ep always points just beyond the end of the row, so
     * the loop simply copies (channels-1) channels until sp reaches ep.
+    *
+    * at_start:        0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+    *            nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
     */
+
    /* GA, GX, XG cases */
    if (row_info->channels == 2)
    {
@@ -450,7 +454,7 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
       {
          if (at_start) /* Skip initial filler */
             ++sp;
-         else          /* Skip initial channels and, for sp, the filler */
+         else          /* Skip initial channel and, for sp, the filler */
             sp += 2, ++dp;
 
          /* For a 1 pixel wide image there is nothing to do */
@@ -462,9 +466,9 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
 
       else if (row_info->bit_depth == 16)
       {
-         if (at_start)
+         if (at_start) /* Skip initial filler */
             sp += 2;
-         else
+         else          /* Skip initial channel and, for sp, the filler */
             sp += 4, dp += 2;
 
          while (sp < ep)
@@ -502,9 +506,9 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
 
       else if (row_info->bit_depth == 16)
       {
-         if (at_start)
+         if (at_start) /* Skip initial filler */
             sp += 2;
-         else
+         else          /* Skip initial channels and, for sp, the filler */
             sp += 8, dp += 6;
 
          while (sp < ep)

pngwrite.c

@@ -1,7 +1,7 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.5.3 [(PENDING RELEASE)]
+ * Last changed in libpng 1.5.6 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 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.)
@@ -99,8 +99,10 @@ png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
          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 &&
+             !(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)))
          {
@@ -273,8 +275,10 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
       {
          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 &&
+             (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)))
          {
@@ -380,7 +384,8 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
       {
          int keep = png_handle_as_unknown(png_ptr, up->name);
          if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location && (up->location & PNG_AFTER_IDAT) &&
+             up->location &&
+             (up->location & PNG_AFTER_IDAT) &&
              ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
              (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
          {
@@ -462,10 +467,9 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
    png_structp png_ptr;
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
-   jmp_buf png_jmpbuf;
+   jmp_buf tmp_jmpbuf;
 #endif
 #endif
-   int i;
 
    png_debug(1, "in png_create_write_struct");
 
@@ -489,12 +493,12 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
    encounter a png_error() will longjmp here.  Since the jmpbuf is
    then meaningless we abort instead of returning. */
 #ifdef USE_FAR_KEYWORD
-   if (setjmp(png_jmpbuf))
+   if (setjmp(tmp_jmpbuf))
 #else
    if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */
 #endif
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 #endif
       PNG_ABORT();
 #endif
@@ -504,49 +508,8 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 #endif /* PNG_USER_MEM_SUPPORTED */
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
-   if (user_png_ver)
-   {
-      i = 0;
-      do
-      {
-         if (user_png_ver[i] != png_libpng_ver[i])
-            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-      } while (png_libpng_ver[i++]);
-   }
-
-   if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
-   {
-     /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
-      * we must recompile any applications that use any older library version.
-      * For versions after libpng 1.0, we will be compatible, so we need
-      * only check the first digit.
-      */
-     if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
-         (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
-         (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
-     {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-        char msg[80];
-
-        if (user_png_ver)
-        {
-            png_snprintf2(msg, 80,
-                "Application built with libpng-%.20s"
-                " but running with %.20s",
-                user_png_ver,
-                png_libpng_ver);
-            png_warning(png_ptr, msg);
-         }
-#else
-         png_warning(png_ptr,
-             "Incompatible libpng version in application and library");
-#endif
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-        png_ptr->flags = 0;
-#endif
-        png_cleanup_needed = 1;
-     }
-   }
+   if (!png_user_version_check(png_ptr, user_png_ver))
+      png_cleanup_needed = 1;
 
    /* Initialize zbuf - compression buffer */
    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
@@ -645,6 +608,9 @@ png_write_image(png_structp png_ptr, png_bytepp image)
 void PNGAPI
 png_write_row(png_structp png_ptr, png_const_bytep row)
 {
+   /* 1.5.6: moved from png_struct to be a local structure: */
+   png_row_info row_info;
+
    if (png_ptr == NULL)
       return;
 
@@ -768,36 +734,31 @@ png_write_row(png_structp png_ptr, png_const_bytep row)
 #endif
 
    /* Set up row info for transformations */
-   png_ptr->row_info.color_type = png_ptr->color_type;
-   png_ptr->row_info.width = png_ptr->usr_width;
-   png_ptr->row_info.channels = png_ptr->usr_channels;
-   png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
-   png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
-      png_ptr->row_info.channels);
+   row_info.color_type = png_ptr->color_type;
+   row_info.width = png_ptr->usr_width;
+   row_info.channels = png_ptr->usr_channels;
+   row_info.bit_depth = png_ptr->usr_bit_depth;
+   row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
 
-   png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
-      png_ptr->row_info.width);
-
-   png_debug1(3, "row_info->color_type = %d", png_ptr->row_info.color_type);
-   png_debug1(3, "row_info->width = %u", png_ptr->row_info.width);
-   png_debug1(3, "row_info->channels = %d", png_ptr->row_info.channels);
-   png_debug1(3, "row_info->bit_depth = %d", png_ptr->row_info.bit_depth);
-   png_debug1(3, "row_info->pixel_depth = %d", png_ptr->row_info.pixel_depth);
-   png_debug1(3, "row_info->rowbytes = %lu",
-       (unsigned long)png_ptr->row_info.rowbytes);
+   png_debug1(3, "row_info->color_type = %d", row_info.color_type);
+   png_debug1(3, "row_info->width = %u", row_info.width);
+   png_debug1(3, "row_info->channels = %d", row_info.channels);
+   png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
+   png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
+   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, png_ptr->row_info.rowbytes);
+   png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Handle interlacing */
    if (png_ptr->interlaced && png_ptr->pass < 6 &&
        (png_ptr->transformations & PNG_INTERLACE))
    {
-      png_do_write_interlace(&(png_ptr->row_info),
-          png_ptr->row_buf + 1, png_ptr->pass);
+      png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
       /* This should always get caught above, but still ... */
-      if (!(png_ptr->row_info.width))
+      if (!(row_info.width))
       {
          png_write_finish_row(png_ptr);
          return;
@@ -805,9 +766,18 @@ png_write_row(png_structp png_ptr, png_const_bytep row)
    }
 #endif
 
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
    /* Handle other transformations */
    if (png_ptr->transformations)
-      png_do_write_transformations(png_ptr);
+      png_do_write_transformations(png_ptr, &row_info);
+#endif
+
+   /* At this point the row_info pixel depth must match the 'transformed' depth,
+    * which is also the output depth.
+    */
+   if (row_info.pixel_depth != png_ptr->pixel_depth ||
+      row_info.pixel_depth != png_ptr->transformed_pixel_depth)
+      png_error(png_ptr, "internal write transform logic error");
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
    /* Write filter_method 64 (intrapixel differencing) only if
@@ -823,12 +793,12 @@ png_write_row(png_structp png_ptr, png_const_bytep row)
        (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
    {
       /* Intrapixel differencing */
-      png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
+      png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
    }
 #endif
 
    /* Find a filter if necessary, filter the row and write it out. */
-   png_write_find_filter(png_ptr, &(png_ptr->row_info));
+   png_write_find_filter(png_ptr, &row_info);
 
    if (png_ptr->write_row_fn != NULL)
       (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
@@ -884,8 +854,6 @@ png_write_flush(png_structp png_ptr)
       {
          /* Write the IDAT and reset the zlib output buffer */
          png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
-         png_ptr->zstream.next_out = png_ptr->zbuf;
-         png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
          wrote_IDAT = 1;
       }
    } while (wrote_IDAT == 1);
@@ -896,8 +864,6 @@ png_write_flush(png_structp png_ptr)
       /* Write the IDAT and reset the zlib output buffer */
       png_write_IDAT(png_ptr, png_ptr->zbuf,
           png_ptr->zbuf_size - png_ptr->zstream.avail_out);
-      png_ptr->zstream.next_out = png_ptr->zbuf;
-      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
    }
    png_ptr->flush_rows = 0;
    png_flush(png_ptr);
@@ -918,13 +884,7 @@ png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
    png_debug(1, "in png_destroy_write_struct");
 
    if (png_ptr_ptr != NULL)
-   {
       png_ptr = *png_ptr_ptr;
-#ifdef PNG_USER_MEM_SUPPORTED
-      free_fn = png_ptr->free_fn;
-      mem_ptr = png_ptr->mem_ptr;
-#endif
-   }
 
 #ifdef PNG_USER_MEM_SUPPORTED
    if (png_ptr != NULL)
@@ -983,7 +943,9 @@ png_write_destroy(png_structp png_ptr)
    jmp_buf tmp_jmp; /* Save jump buffer */
 #endif
    png_error_ptr error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_error_ptr warning_fn;
+#endif
    png_voidp error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_free_ptr free_fn;
@@ -992,7 +954,8 @@ png_write_destroy(png_structp png_ptr)
    png_debug(1, "in png_write_destroy");
 
    /* Free any memory zlib uses */
-   deflateEnd(&png_ptr->zstream);
+   if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
+      deflateEnd(&png_ptr->zstream);
 
    /* Free our memory.  png_free checks NULL for us. */
    png_free(png_ptr, png_ptr->zbuf);
@@ -1005,10 +968,6 @@ png_write_destroy(png_structp png_ptr)
    png_free(png_ptr, png_ptr->paeth_row);
 #endif
 
-#ifdef PNG_TIME_RFC1123_SUPPORTED
-   png_free(png_ptr, png_ptr->time_buffer);
-#endif
-
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
    /* Use this to save a little code space, it doesn't free the filter_costs */
    png_reset_filter_heuristics(png_ptr);
@@ -1018,11 +977,13 @@ png_write_destroy(png_structp png_ptr)
 
 #ifdef PNG_SETJMP_SUPPORTED
    /* Reset structure */
-   png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
 #endif
 
    error_fn = png_ptr->error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    warning_fn = png_ptr->warning_fn;
+#endif
    error_ptr = png_ptr->error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    free_fn = png_ptr->free_fn;
@@ -1031,14 +992,16 @@ png_write_destroy(png_structp png_ptr)
    png_memset(png_ptr, 0, png_sizeof(png_struct));
 
    png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_ptr->warning_fn = warning_fn;
+#endif
    png_ptr->error_ptr = error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_ptr->free_fn = free_fn;
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+   png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
 #endif
 }
 
@@ -1451,6 +1414,9 @@ png_set_compression_strategy(png_structp png_ptr, int strategy)
    png_ptr->zlib_strategy = strategy;
 }
 
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
 void PNGAPI
 png_set_compression_window_bits(png_structp png_ptr, int window_bits)
 {
@@ -1491,8 +1457,8 @@ png_set_compression_method(png_structp png_ptr, int method)
    png_ptr->zlib_method = method;
 }
 
-/* The following were added to libpng-1.5.3 */
-#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION
+/* The following were added to libpng-1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 void PNGAPI
 png_set_text_compression_level(png_structp png_ptr, int level)
 {
@@ -1529,6 +1495,9 @@ png_set_text_compression_strategy(png_structp png_ptr, int strategy)
    png_ptr->zlib_text_strategy = strategy;
 }
 
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
 void PNGAPI
 png_set_text_compression_window_bits(png_structp png_ptr, int window_bits)
 {
@@ -1568,8 +1537,8 @@ png_set_text_compression_method(png_structp png_ptr, int method)
    png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_METHOD;
    png_ptr->zlib_text_method = method;
 }
-#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
-/* end of API added to libpng-1.5.3 */
+#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+/* end of API added to libpng-1.5.4 */
 
 void PNGAPI
 png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
@@ -1637,7 +1606,7 @@ png_write_png(png_structp png_ptr, png_infop info_ptr,
 #endif
 
 #ifdef PNG_WRITE_FILLER_SUPPORTED
-   /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */
+   /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
    if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
       png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
 

pngwtran.c

@@ -1,7 +1,7 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.6 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 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.)
@@ -15,11 +15,12 @@
 
 #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_structp png_ptr)
+png_do_write_transformations(png_structp png_ptr, png_row_infop row_info)
 {
    png_debug(1, "in png_do_write_transformations");
 
@@ -31,8 +32,8 @@ png_do_write_transformations(png_structp png_ptr)
       if (png_ptr->write_user_transform_fn != NULL)
          (*(png_ptr->write_user_transform_fn)) /* User write transform
                                                  function */
-             (png_ptr,                    /* png_ptr */
-             &(png_ptr->row_info),           /* row_info: */
+             (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 */
@@ -44,50 +45,50 @@ png_do_write_transformations(png_structp png_ptr)
 
 #ifdef PNG_WRITE_FILLER_SUPPORTED
    if (png_ptr->transformations & PNG_FILLER)
-      png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1,
-         !(png_ptr->flags & PNG_FILLER_AFTER));
+      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(&(png_ptr->row_info), png_ptr->row_buf + 1);
+      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(&(png_ptr->row_info), png_ptr->row_buf + 1,
+      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(&(png_ptr->row_info), png_ptr->row_buf + 1);
+      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(&(png_ptr->row_info), png_ptr->row_buf + 1,
+      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(&(png_ptr->row_info), png_ptr->row_buf + 1);
+      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(&(png_ptr->row_info), png_ptr->row_buf + 1);
+      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(&(png_ptr->row_info), png_ptr->row_buf + 1);
+      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(&(png_ptr->row_info), png_ptr->row_buf + 1);
+      png_do_invert(row_info, png_ptr->row_buf + 1);
 #endif
 }
 
@@ -563,6 +564,7 @@ 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  */

projects/owatcom/libpng.tgt

@@ -0,0 +1,383 @@
+40
+targetIdent
+0
+MProject
+1
+MComponent
+0
+2
+WString
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projects/owatcom/libpng.wpj

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+# Locations of zlib and (if required) awk (change as required:)
+set zlib=..\..\..\zlib
+set awk=
+#
+@if not exist pngconfig.dfa $(MAKE) $(__MAKEOPTS__) -f pngconfig.mak defaults
+@if exist config.inf type config.inf
+@echo Checking for the libpng configuration file pnglibconf.h
+$(MAKE) $(__MAKEOPTS__) -f pngconfig.mak
+4
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+@type pngconfig.inf
+3
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projects/owatcom/pngconfig.mak

@@ -0,0 +1,160 @@
+# This is an OpenWatcom make file which builds pnglibconf.h - the libpng
+# configuration header.  You can ignore this file if you don't need to
+# configure libpng; a default configuration will be built.
+#
+# For more information build libpng.wpj under the IDE and then read the
+# generated files:
+#
+#    config.inf: Basic configuration information for a standard build.
+#    pngconfig.dfa: Advanced configuration for non-standard libpng builds.
+#
+DELETE=rm -f
+ECHO=echo
+COPY=copy
+#
+# If your configuration needs to test compiler flags when building
+# pnglibconf.h you may need to override the following on the wmake command
+# line:
+CFLAGS=
+CC=wcl386
+CPP=$(CC) -pw0
+#
+# Read awk from the environment if set, else it can be set on the command
+# line (the default approach is to set the %awk% environment variable in the
+# IDE libpng.wpj 'before' rule - this setting is local.)
+!ifdef %awk
+AWK=$(%awk)
+!endif
+#
+# pnglibconf.h must exist in the source directory, this is the final rule
+# which copies the local built version (and this is the default target for
+# this makefile.)
+..\..\pnglibconf.h: pnglibconf.h
+ $(COPY) pnglibconf.h $@
+
+!ifdef AWK
+# CPPFLAGS should contain the options to control the result,
+# but DEFS and CFLAGS are also supported here, override
+# as appropriate
+DFNFLAGS = $(DEFS) $(CPPFLAGS) $(CFLAGS)
+
+pnglibconf.h: pnglibconf.dfn
+ $(DELETE) $@ dfn.c dfn1.out dfn2.out
+ $(ECHO) $#include "pnglibconf.dfn" >dfn.c
+ $(CPP) $(DFNFLAGS) dfn.c >dfn1.out
+ $(AWK) -f << dfn1.out >dfn2.out
+/^.*PNG_DEFN_MAGIC-.*-PNG_DEFN_END.*$$/{
+ sub(/^.*PNG_DEFN_MAGIC-/, "")
+ sub(/ *-PNG_DEFN_END.*$$/, "")
+ gsub(/ *@@@ */, "")
+ print
+}
+<<
+ $(COPY) dfn2.out $@
+ @type << >pngconfig.inf
+This is a locally configurable build of libpng.lib; for configuration
+instructions consult and edit projects/openwatcom/pngconfig.dfa
+<<
+ $(DELETE) dfn.c dfn1.out dfn2.out
+
+pnglibconf.dfn: ..\..\scripts\pnglibconf.dfa ..\..\scripts\options.awk pngconfig.dfa
+ $(DELETE) $@ dfn1.out dfn2.out
+ $(AWK) -f ..\..\scripts\options.awk out=dfn1.out ..\..\scripts\pnglibconf.dfa pngconfig.dfa $(DFA_XTRA) 1>&2
+ $(AWK) -f ..\..\scripts\options.awk out=dfn2.out dfn1.out 1>&2
+ $(COPY) dfn2.out $@
+ $(DELETE) dfn1.out dfn2.out
+
+!else
+# The following lines are used to copy scripts\pnglibconf.h.prebuilt and make
+# the required change to the calling convention.
+#
+# By default libpng is built to use the __cdecl calling convention on
+# Windows.  This gives compatibility with MSVC and GCC.  Unfortunately it
+# does not work with OpenWatcom because OpenWatcom implements longjmp using
+# the __watcall convention (compared with both MSVC and GCC which use __cdecl
+# for library functions.)
+#
+# Thus the default must be changed to build on OpenWatcom and, once changed,
+# the result will not be compatible with applications built using other
+# compilers (in fact attempts to build will fail at compile time.)
+#
+pnglibconf.h: ..\..\scripts\pnglibconf.h.prebuilt .existsonly
+ @$(ECHO) .
+ @$(ECHO) .
+ @$(ECHO) $$(AWK) NOT AVAILABLE: COPYING scripts\pnglibconf.h.prebuilt
+ @$(ECHO) .
+ @$(ECHO) .
+ vi -q -k ":1,$$s/PNG_API_RULE 0$$/PNG_API_RULE 2/\n:w! $@\n:q!\n" ..\..\scripts\pnglibconf.h.prebuilt
+ @$(ECHO) .
+ @$(ECHO) .
+ @$(ECHO) YOU HAVE A DEFAULT CONFIGURATION BECAUSE YOU DO NOT HAVE AWK!
+ @$(ECHO) .
+ @$(ECHO) .
+ @type << >pngconfig.inf
+This is the default configuration of libpng.lib, if you wish to
+change the configuration please consult the instructions in
+projects/owatcom/pngconfig.dfa.
+<<
+
+!endif
+
+# Make the default files
+defaults: .symbolic
+ @$(COPY) << config.inf
+$# The libpng project is incompletely configured.  To complete configuration
+$# please complete the following steps:
+$#
+$#   1) Edit the 'before' rule of libpng.wpj (from the IDE) to define the
+$#      locations of the zlib include file zlib.h and the built zlib library,
+$#      zlib.lib.
+$#
+$#   2) If you want to change libpng to a non-standard configuration also
+$#      change the definition of 'awk' in the before rule to the name of your
+$#      awk command.  For more instructions on configuration read
+$#      pngconfig.dfa.
+$#
+$#   3) Delete this file (config.inf).
+<<
+ @$(COPY) << pngconfig.dfa
+$# pngconfig.dfa: this file contains configuration options for libpng.
+$# If emtpy the standard configuration will be built.  For this file to be
+$# used a working version of the program 'awk' is required and the program
+$# must be identified in the 'before' rule of the project.
+$#
+$# If you don't already have 'awk', or the version of awk you have seems not
+$# to work, download Brian Kernighan's awk (Brian Kernighan is the author of
+$# awk.)  You can find source code and a built executable (called awk95.exe)
+$# here:
+$#
+$#     http://www.cs.princeton.edu/~bwk/btl.mirror/
+$#
+$# The executable works just fine.
+$#
+$# If build issues errors after a change to pngconfig.dfa you have entered
+$# inconsistent feature requests, or even malformed requests, in
+$# pngconfig.dfa.  The error messages from awk should be comprehensible, but
+$# if not simply go back to the start (nothing but comments in this file) and
+$# enter configuration lines one by one until one produces an error.  (Or, of
+$# course, do the standard binary chop.)
+$#
+$# You need to rebuild everything after a change to pnglibconf.dfa - i.e. you
+$# must do Actions/Mark All Targets for Remake.  This is because the compiler
+$# generated dependency information (as of OpenWatcom 1.9) does not record the
+$# dependency on pnglibconf.h correctly.
+$#
+$# If awk isn't set then this file is bypassed.  If you just want the standard
+$# configuration it is automatically produced from the distributed version
+$# (scripts\pnglibconf.h.prebuilt) by editting PNG_API_RULE to 2 (to force use
+$# of the OpenWatcom library calling convention.)
+$#
+<<
+
+clean:: .symbolic
+ $(DELETE) ..\..\pnglibconf.h pnglibconf.* dfn.c *.out pngconfig.inf
+ $(DELETE) *.obj *.mbr *.sym *.err *.pch libpng.mk
+ $(DELETE) libpng.lib libpng.lbr libpng.lb1 libpng.cbr libpng.mk1
+ $(DELETE) pngtest.exe pngtest.map pngtest.lk1 pngtest.mk1
+ $(DELETE) pngvalid.exe pngvalid.map pngvalid.lk1 pngvalid.mk1
+
+distclean:: clean .symbolic
+ $(DELETE) zlib.inf awk.inf config.inf pngconfig.dfa

projects/owatcom/pngtest.tgt

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+"$(%zlib);$(%watcom)/h;$(%watcom)/h/nt"
+0
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+$(%zlib)
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projects/visualc71/PRJ0041.mak

@@ -9,7 +9,7 @@ all: $(IntDir)\alloc.h \
 	 $(IntDir)\strings.h \
 	 $(IntDir)\unistd.h \
 	 $(IntDir)\unixio.h
-	 
+
 $(IntDir)\alloc.h \
 $(IntDir)\fp.h \
 $(IntDir)\m68881.h \

projects/vstudio/libpng/libpng.vcxproj

@@ -118,7 +118,7 @@
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
-      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;_USRDLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <FloatingPointExceptions>false</FloatingPointExceptions>
@@ -175,7 +175,7 @@
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
-      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;_USRDLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <FloatingPointExceptions>false</FloatingPointExceptions>
       <TreatWChar_tAsBuiltInType>false</TreatWChar_tAsBuiltInType>
       <PrecompiledHeaderFile>pngpriv.h</PrecompiledHeaderFile>

projects/vstudio/pngvalid/pngvalid.vcxproj

@@ -81,7 +81,7 @@
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
-      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
@@ -146,7 +146,7 @@
       <Optimization>Full</Optimization>
       <FunctionLevelLinking>false</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
-      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>

projects/vstudio/readme.txt

@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.5.3beta02 - April 3, 2011
+libpng version 1.5.6beta02 - September 26, 2011
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 

projects/vstudio/zlib.props

@@ -2,9 +2,9 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.5.3beta02 - April 3, 2011
+ * libpng version 1.5.6beta02 - September 26, 2011
  *
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -19,12 +19,19 @@
   <PropertyGroup Label="Globals">
     <!-- Place the name of the directory containing the source of zlib used for
 	 debugging in this property.
+
          The directory need only contain the '.c' and '.h' files from the
 	 source.
+
 	 If you use a relative directory name (as below) then it must be
 	 relative to the project directories; these are one level deepers than
 	 the directories containing this file.
+
+	 If the version of zlib you use does not match that used when the
+	 distribution was built you will get warnings from pngtest that the zlib
+	 versions do not match.  The zlib version used in this build is recorded
+	 below:
      -->
-    <ZLibSrcDir>..\..\..\..\zlib-1.2.4</ZLibSrcDir>
+    <ZLibSrcDir>..\..\..\..\zlib-1.2.5</ZLibSrcDir>
   </PropertyGroup>
 </Project>

projects/vstudio/zlib/zlib.vcxproj

@@ -84,7 +84,7 @@
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
     <ClCompile>
-      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;_USRDLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <WarningLevel>TurnOffAllWarnings</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
@@ -99,7 +99,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
-      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;_USRDLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <WarningLevel>TurnOffAllWarnings</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
@@ -156,7 +156,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;_USRDLL;DEBUGZLIB_EXPORTS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <WarningLevel>Level3</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
     </ClCompile>

scripts/README.txt

@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.5.3beta02 - April 3, 2011
+Makefiles for  libpng version 1.5.6beta02 - September 26, 2011
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng15.so.15.1.5.3beta02)
+                       (gcc, creates libpng15.so.15.1.5.6beta02)
  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 libpng15.so.15.1.5.3beta02)
+                       (gcc, creates libpng15.so.15.1.5.6beta02)
  makefile.freebsd  =>  FreeBSD makefile
  makefile.gcc      =>  Generic gcc makefile
  makefile.hpgcc    =>  HPUX makefile using gcc
@@ -35,19 +35,18 @@ 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 libpng15.so.15.1.5.3beta02)
+                       creates libpng15.so.15.1.5.6beta02)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng15.so.15.1.5.3beta02)
+                       creates libpng15.so.15.1.5.6beta02)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng15.so.15.1.5.3beta02)
+                       creates libpng15.so.15.1.5.6beta02)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile
  makefile.64sunu   =>  Sun Ultra 64-bit makefile
  makefile.tc3      =>  Turbo C 3.0 makefile
  makefile.vcwin32  =>  makefile for Microsoft Visual C++ 4.0 and later
- makefile.watcom   =>  Watcom 10a+ Makefile, 32-bit flat memory model
  makevms.com       =>  VMS build script
  smakefile.ppc     =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
                        (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
@@ -58,7 +57,7 @@ Other supporting scripts:
  libpng-config-body.in => used by several makefiles to create libpng-config
  libpng-config-head.in => used by several makefiles to create libpng-config
  libpng.pc.in      =>  Used by several makefiles to create libpng.pc
- pngwin.rc         =>  Used by the visualc6 and visualc71 projects.
+ pngwin.rc         =>  Used by the visualc71 project.
  pngwin.def        =>  Used by makefile.os2
  pngwin.dfn        =>  Used to maintain pngwin.def
  SCOPTIONS.ppc     =>  Used with smakefile.ppc

scripts/libpng-config-head.in

@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.5.3beta02
+version=1.5.6beta02
 prefix=""
 libdir=""
 libs=""

scripts/libpng.pc.in

@@ -5,6 +5,6 @@ includedir=@includedir@/libpng15
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.5.3beta02
+Version: 1.5.6beta02
 Libs: -L${libdir} -lpng15
 Cflags: -I${includedir}

scripts/makefile.cegcc

@@ -23,7 +23,7 @@
 
 VERMAJ = 1
 VERMIN = 5
-VERMIC = 3
+VERMIC = 6
 VER = $(VERMAJ).$(VERMIN).$(VERMIC)
 NAME = libpng
 PACKAGE = $(NAME)-$(VER)

scripts/makefile.darwin

@@ -37,10 +37,11 @@ MKDIR_P=mkdir -p
 LN_SF=ln -sf
 RANLIB=ranlib
 RM_F=/bin/rm -f
+ARCH="-arch i386 -arch x86_64"
 
 # CFLAGS=-I$(ZLIBINC) -W -Wall -O3 -funroll-loops
-CFLAGS=-I$(ZLIBINC) -W -Wall -O -funroll-loops
-LDFLAGS=-L. -L$(ZLIBLIB) -lpng15 -lz
+CFLAGS=-I$(ZLIBINC) -W -Wall -O -funroll-loops $(ARCH)
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng15 -lz $(ARCH)
 
 INCPATH=$(prefix)/include
 LIBPATH=$(exec_prefix)/lib

scripts/makefile.linux

@@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng15
 PNGMAJ = 15
-RELEASE = 3
+RELEASE = 6
 
 # Shared library names:
 LIBSO=$(LIBNAME).so

scripts/makefile.ne12bsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng15
 
 LIB=	png15
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.5.3beta02
+SHLIB_MINOR=	1.5.6beta02
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c

scripts/makefile.netbsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include
 
 LIB=	png
 SHLIB_MAJOR=	15
-SHLIB_MINOR=	1.5.3beta02
+SHLIB_MINOR=	1.5.6beta02
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c

scripts/makefile.openbsd

@@ -11,7 +11,7 @@ LIBDIR=	${PREFIX}/lib
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	15
-SHLIB_MINOR=	1.5.3beta02
+SHLIB_MINOR=	1.5.6beta02
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \

scripts/makefile.watcom

@@ -1,122 +0,0 @@
-# Makefile for libpng
-# Watcom C/C++ 10.0 and later, 32-bit protected mode, flat memory model
-
-# Copyright (C) 2000, Pawel Mrochen, based on makefile.msc which is
-# copyright 1995 Guy Eric Schalnat, Group 42, Inc.
-#
-# This code is released under the libpng license.
-# For conditions of distribution and use, see the disclaimer
-# and license in png.h
-
-# To use, do "wmake /f scripts\makefile.watcom"
-
-
-# ---------------------- Watcom C/C++ 10.0 and later -----------------------
-
-# Where the zlib library and include files are located
-ZLIBLIB=..\zlib
-ZLIBINC=..\zlib
-
-# Target OS
-OS=DOS
-#OS=NT
-
-# Target CPU
-CPU=6		# Pentium Pro
-#CPU=5		# Pentium
-
-# Calling convention
-CALLING=r	# registers
-#CALLING=s	# stack
-
-# Uncomment next to put error messages in a file
-#ERRFILE=>>pngerrs
-
-# --------------------------------------------------------------------------
-
-
-CC=wcc386
-CFLAGS=-$(CPU)$(CALLING) -fp$(CPU) -fpi87 -oneatx -mf -bt=$(OS) -i=$(ZLIBINC) -zq
-LD=wcl386
-LDFLAGS=-zq
-
-O=.obj
-
-OBJS1=png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
-OBJS2=pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
-OBJS3=pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
-
-
-all: test
-
-# see scripts/pnglibconf.mak for more options
-# to support watcom calling conventions it is necessary to set PNG_API_RULE to 2
-# in pnglibconf.h - copy scripts/pnglibconf.h.prebuilt, delete the first line and change
-# the definition of PNG_API_RULE from 0 to 2.
-#
-# If you know how to do this with the Watcom build system please supply a patch
-# for this makefile to the PNG implementation list.
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	@echo please copy scripts/pnglibconf.h.prebuilt and change PNG_API_RULE to 2
-
-png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngset$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngget$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngmem$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngrio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngtest$(O): png.h pngconf.h pnglibconf.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
-	wlib -b -c -n -q libpng.lib $(OBJS1)
-	wlib -b -c -q libpng.lib $(OBJS2)
-	wlib -b -c -q libpng.lib $(OBJS3)
-
-pngtest.exe: pngtest.obj libpng.lib
-	$(LD) $(LDFLAGS) pngtest.obj libpng.lib $(ZLIBLIB)\zlib.lib
-
-test: pngtest.exe .symbolic
-	pngtest.exe
-
-
-# End of makefile for libpng

scripts/options.awk

@@ -48,7 +48,7 @@ BEGIN{
    deb=0                        # debug - set on command line
    everything=""                # do not override defaults
    logunsupported=0             # write unsupported options too
-   
+
    # Precreate arrays
    option[""] = ""    # list of all options: default enabled/disabled
    done[""] = 1       # marks option as having been output
@@ -301,7 +301,7 @@ pre != 0 && $1 == "chunk" && NF >= 2{
 #   macro is not defined.  The default value will be re-tokenised.
 #   (BTW: this is somewhat restrictive, it mainly exists for the
 #   support of non-standard configurations and numeric parameters,
-#   see the uses in scripts/options.dat 
+#   see the uses in scripts/options.dat
 
 $1 == "setting" && (NF == 2 || NF >= 3 && ($3 == "requires" || $3 == "default")){
    reqs = ""

scripts/pnglibconf.dfa

@@ -6,7 +6,7 @@
 #
 com pnglibconf.h - library build configuration
 com
-com libpng version 1.5.0 - January 6, 2011
+com libpng version 1.5.3 -  July 7, 2011
 com
 com Copyright (c) 1998-2011 Glenn Randers-Pehrson
 com
@@ -43,7 +43,7 @@ file pnglibconf.h scripts/pnglibconf.dfa PNGLCONF_H
 
 # The following setting, option and chunk values can all be changed
 # while building libpng:
-# 
+#
 # setting: change 'setting' lines to fine tune library performance,
 #   changes to the settings don't affect the libpng API functionally
 #
@@ -62,7 +62,7 @@ file pnglibconf.h scripts/pnglibconf.dfa PNGLCONF_H
 # don't want in that file in that file.  You can also turn on options
 # using PNG_<option>_SUPPORTED.  When you have finished rerun
 # configure and rebuild pnglibconf.h file with -DPNG_USER_CONFIG:
-# 
+#
 #  make clean
 #  CPPFLAGS='-DPNG_USER_CONFIG' ./configure
 #  make pnglibconf.h
@@ -73,7 +73,7 @@ file pnglibconf.h scripts/pnglibconf.dfa PNGLCONF_H
 #
 # 2) Add definitions of the settings you want to change to
 # CPPFLAGS; for example:
-# 
+#
 #   -DPNG_DEFAULT_READ_MACROS=0
 #
 # (This would change the default to *not* use read macros.)  Be
@@ -193,11 +193,11 @@ option FLOATING_ARITHMETIC
 option FLOATING_POINT enables ok_math
 option FIXED_POINT enables ok_math
 
-# Added at libpng version 1.4.0 
+# Added at libpng version 1.4.0
 
 option ERROR_TEXT
 
-# The following is always on (defined empty) 
+# The following is always on (defined empty)
 
 setting CALLOC_SUPPORTED default
 
@@ -214,9 +214,9 @@ option STDIO
 option CONSOLE_IO requires STDIO
 
 # Note: prior to 1.5.0 this option could not be disabled if STDIO
-# was enabled.
+# was enabled.  Prior to 1.5.3 this option required STDIO
 
-option TIME_RFC1123 requires STDIO
+option TIME_RFC1123
 
 # PNG_SETJMP_NOT_SUPPORTED is an old equivalent for NO_SETJMP
 
@@ -267,10 +267,10 @@ option SET_USER_LIMITS enables SET_CHUNK_CACHE_LIMIT
 option SET_USER_LIMITS enables SET_CHUNK_MALLOC_LIMIT
 
 # Added at libpng-1.0.16 and 1.2.6.  To accept all valid PNGs no matter
-# how large, set these two limits to 0x7fffffffL
+# how large, set these two limits to 0x7fffffff
 
-setting USER_WIDTH_MAX default 1000000L
-setting USER_HEIGHT_MAX default 1000000L
+setting USER_WIDTH_MAX default 1000000
+setting USER_HEIGHT_MAX default 1000000
 
 # Added at libpng-1.2.43.  To accept all valid PNGs no matter
 # how large, set these two limits to 0.
@@ -293,8 +293,10 @@ option READ enables READ_INTERLACING
 
 # Disabling READ_16BIT does not disable reading 16-bit PNG files, but it
 # forces them to be chopped down to 8-bit, and disables any 16-bit
-# processing after that has happened.  You need to be sure to enable READ_16_TO_8
-# when you disable READ_16BIT for this to work properly.
+# processing after that has happened.  You need to be sure to enable
+# READ_SCALE_16_TO_8 or READ_STRIP_16_TO_8 when you disable READ_16BIT for
+# this to work properly.  You should disable the other option if you need to
+# ensure a particular convertion (otherwise the app can chose.)
 
 option READ_16BIT requires READ enables 16BIT
 
@@ -311,11 +313,14 @@ option READ_BGR requires READ_TRANSFORMS
 option READ_SWAP requires READ_TRANSFORMS READ_16BIT
 option READ_PACKSWAP requires READ_TRANSFORMS
 option READ_INVERT requires READ_TRANSFORMS
-option READ_BACKGROUND requires READ_TRANSFORMS
-option READ_16_TO_8 requires READ_TRANSFORMS
+option READ_BACKGROUND requires READ_TRANSFORMS enables READ_STRIP_ALPHA
+option READ_STRIP_16_TO_8 requires READ_TRANSFORMS
+option READ_SCALE_16_TO_8 requires READ_TRANSFORMS
 option READ_FILLER requires READ_TRANSFORMS
 option READ_GAMMA requires READ_TRANSFORMS enables READ_gAMA
 option READ_GRAY_TO_RGB requires READ_TRANSFORMS
+
+option READ_ALPHA_MODE requires READ_TRANSFORMS enables READ_GAMMA
 option READ_SWAP_ALPHA requires READ_TRANSFORMS
 option READ_INVERT_ALPHA requires READ_TRANSFORMS
 option READ_STRIP_ALPHA requires READ_TRANSFORMS
@@ -340,12 +345,14 @@ option READ_COMPOSITE_NODIV requires READ
 option INCH_CONVERSIONS
 = INCH_CONVERSIONS INCH_CONVERSIONS
 
+# API to build a grayscale palette
+
+option BUILD_GRAYSCALE_PALETTE
+
 # IN DEVELOPMENT
-# These are currently experimental features, define them if you want
+# These are currently experimental features; define them if you want
 
-# Very little testing, not enabled by default.
-
-option READ_16_TO_8_ACCURATE_SCALE requires READ disabled
+# NOTHING HERE
 
 # WRITE options
 
@@ -546,6 +553,11 @@ option SAVE_INT_32 requires WRITE
 
 # png_save_int_32 is required by the ancillary chunks oFFs and pCAL
 
+# added at libpng-1.5.4
+
+option WRITE_OPTIMIZE_CMF requires WRITE
+
+option READ_COMPRESSED_TEXT disabled
 option READ_iCCP enables READ_COMPRESSED_TEXT
 option READ_iTXt enables READ_COMPRESSED_TEXT
 option READ_zTXt enables READ_COMPRESSED_TEXT
@@ -554,6 +566,7 @@ option READ_COMPRESSED_TEXT enables READ_TEXT
 option WRITE_oFFs enables SAVE_INT_32
 option WRITE_pCAL enables SAVE_INT_32
 
+option WRITE_COMPRESSED_TEXT disabled
 option WRITE_iCCP enables WRITE_COMPRESSED_TEXT
 option WRITE_iTXt enables WRITE_COMPRESSED_TEXT
 option WRITE_zTXt enables WRITE_COMPRESSED_TEXT

scripts/pnglibconf.h.prebuilt

@@ -3,7 +3,7 @@
 
 /* pnglibconf.h - library build configuration */
 
-/* libpng version 1.5.0 - last changed on February 11, 2011 */
+/* libpng version 1.5.4 - last changed on June 22, 2011 */
 
 /* Copyright (c) 1998-2011 Glenn Randers-Pehrson */
 
@@ -17,7 +17,7 @@
 /* pnglibconf.dfa with respect to the dependencies between the following */
 /* symbols.  It is much better to generate a new file using */
 /* scripts/libpngconf.mak */
-  
+
 #ifndef PNGLCONF_H
 #define PNGLCONF_H
 /* settings */
@@ -33,8 +33,8 @@
 #define PNG_sCAL_PRECISION 5
 #define PNG_USER_CHUNK_CACHE_MAX 0
 #define PNG_USER_CHUNK_MALLOC_MAX 0
-#define PNG_USER_HEIGHT_MAX 1000000L
-#define PNG_USER_WIDTH_MAX 1000000L
+#define PNG_USER_HEIGHT_MAX 1000000
+#define PNG_USER_WIDTH_MAX 1000000
 #define PNG_WEIGHT_SHIFT 8
 #define PNG_ZBUF_SIZE 8192
 /* end of settings */
@@ -43,11 +43,13 @@
 #define PNG_ALIGN_MEMORY_SUPPORTED
 #define PNG_BENIGN_ERRORS_SUPPORTED
 #define PNG_bKGD_SUPPORTED
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
 #define PNG_CHECK_cHRM_SUPPORTED
 #define PNG_cHRM_SUPPORTED
 #define PNG_CONSOLE_IO_SUPPORTED
 #define PNG_CONVERT_tIME_SUPPORTED
 #define PNG_EASY_ACCESS_SUPPORTED
+/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
 #define PNG_ERROR_TEXT_SUPPORTED
 #define PNG_FIXED_POINT_SUPPORTED
 #define PNG_FLOATING_ARITHMETIC_SUPPORTED
@@ -67,13 +69,14 @@
 #define PNG_POINTER_INDEXING_SUPPORTED
 #define PNG_PROGRESSIVE_READ_SUPPORTED
 #define PNG_READ_16BIT_SUPPORTED
-#define PNG_READ_16_TO_8_SUPPORTED
+#define PNG_READ_ALPHA_MODE_SUPPORTED
 #define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
 #define PNG_READ_BACKGROUND_SUPPORTED
 #define PNG_READ_BGR_SUPPORTED
 #define PNG_READ_bKGD_SUPPORTED
 #define PNG_READ_cHRM_SUPPORTED
 #define PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
 #define PNG_READ_EXPAND_16_SUPPORTED
 #define PNG_READ_EXPAND_SUPPORTED
 #define PNG_READ_FILLER_SUPPORTED
@@ -96,10 +99,12 @@
 #define PNG_READ_QUANTIZE_SUPPORTED
 #define PNG_READ_RGB_TO_GRAY_SUPPORTED
 #define PNG_READ_sBIT_SUPPORTED
+#define PNG_READ_SCALE_16_TO_8_SUPPORTED
 #define PNG_READ_sCAL_SUPPORTED
 #define PNG_READ_SHIFT_SUPPORTED
 #define PNG_READ_sPLT_SUPPORTED
 #define PNG_READ_sRGB_SUPPORTED
+#define PNG_READ_STRIP_16_TO_8_SUPPORTED
 #define PNG_READ_STRIP_ALPHA_SUPPORTED
 #define PNG_READ_SUPPORTED
 #define PNG_READ_SWAP_ALPHA_SUPPORTED
@@ -113,7 +118,6 @@
 #define PNG_READ_USER_CHUNKS_SUPPORTED
 #define PNG_READ_USER_TRANSFORM_SUPPORTED
 #define PNG_READ_zTXt_SUPPORTED
-#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
 #define PNG_SAVE_INT_32_SUPPORTED
 #define PNG_sBIT_SUPPORTED
 #define PNG_sCAL_SUPPORTED
@@ -142,6 +146,8 @@
 #define PNG_WRITE_BGR_SUPPORTED
 #define PNG_WRITE_bKGD_SUPPORTED
 #define PNG_WRITE_cHRM_SUPPORTED
+#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 #define PNG_WRITE_FILLER_SUPPORTED
 #define PNG_WRITE_FILTER_SUPPORTED
 #define PNG_WRITE_FLUSH_SUPPORTED
@@ -152,9 +158,9 @@
 #define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
 #define PNG_WRITE_INVERT_ALPHA_SUPPORTED
 #define PNG_WRITE_INVERT_SUPPORTED
-#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION
 #define PNG_WRITE_iTXt_SUPPORTED
 #define PNG_WRITE_oFFs_SUPPORTED
+#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
 #define PNG_WRITE_PACK_SUPPORTED
 #define PNG_WRITE_PACKSWAP_SUPPORTED
 #define PNG_WRITE_pCAL_SUPPORTED
@@ -177,8 +183,5 @@
 #define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 #define PNG_WRITE_zTXt_SUPPORTED
 #define PNG_zTXt_SUPPORTED
-#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
-/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
-/*#undef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED*/
 /* end of options */
 #endif /* PNGLCONF_H */

scripts/pnglibconf.mak

@@ -1,6 +1,6 @@
 #!/usr/bin/make -f
 # pnglibconf.mak - standard make lines for pnglibconf.h
-# 
+#
 # These lines are copied from Makefile.am, they illustrate
 # how to automate the build of pnglibconf.h from scripts/pnglibconf.dfa
 # given 'awk' and 'sed'

scripts/symbols.def

@@ -5,7 +5,7 @@
 LIBRARY
 
 EXPORTS
-;Version 1.5.3beta02
+;Version 1.5.6beta02
  png_access_version_number @1
  png_set_sig_bytes @2
  png_sig_cmp @3
@@ -232,3 +232,10 @@ EXPORTS
  png_set_text_compression_strategy @224
  png_set_text_compression_window_bits @225
  png_set_text_compression_method @226
+ png_set_alpha_mode @227
+ png_set_alpha_mode_fixed @228
+ png_set_scale_16 @229
+ png_get_cHRM_XYZ @230
+ png_get_cHRM_XYZ_fixed @231
+ png_set_cHRM_XYZ @232
+ png_set_cHRM_XYZ_fixed @233

test-pngvalid-full.sh

@@ -7,9 +7,9 @@ echo >> pngtest-log.txt
 echo "============ pngvalid-full.sh ==============" >> pngtest-log.txt
 
 echo "Running test-pngvalid-full.sh"
-for gamma in threshold transform sbit 16-to-8
+for gamma in threshold transform sbit 16-to-8 background alpha-mode "transform --expand16" "background --expand16" "alpha-mode --expand16"
 do
-   if ./pngvalid "--gamma-$gamma" >> pngtest-log.txt 2>&1
+   if ./pngvalid --gamma-$gamma >> pngtest-log.txt 2>&1
    then
       echo "  PASS:" pngvalid "--gamma-$gamma"
    else