[libpng16] Imported from libpng-1.6.0beta35.tar

by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old GCCs.)
ARM support is enabled by default in zlib.props (unsupported by Microsoft) and
ARM compilation is made possible by deleting the check for x86. The test programs
cannot be run because they are not signed.

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.6.0beta25 - June 16, 2012
+Libpng 1.6.0beta35 - December 22, 2012
 
 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.
@@ -9,20 +9,20 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.6.0beta25.tar.xz (LZMA-compressed, recommended)
-   1.6.0beta25.tar.gz
-   1.6.0beta25.tar.bz2
+   1.6.0beta35.tar.xz (LZMA-compressed, recommended)
+   1.6.0beta35.tar.gz
+   1.6.0beta35.tar.bz2
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp160b25.7z  (LZMA-compressed, recommended)
-   lp160b25.zip
+   lp160b35.7z  (LZMA-compressed, recommended)
+   lp160b35.zip
 
 Other information:
 
-   1.6.0beta25-README.txt
-   1.6.0beta25-LICENSE.txt
+   1.6.0beta35-README.txt
+   1.6.0beta35-LICENSE.txt
 
 Changes since the last public release (1.5.7):
 
@@ -349,7 +349,7 @@ Version 1.6.0beta20 [March 29, 2012]
     iCCP profile over writing the sRGB chunk, controlled by the
     PNG_sRGB_PROFILE_CHECKS option.
   Revised png_set_text_2() to avoid potential memory corruption (fixes
-    CVE-2011-3048).
+    CVE-2011-3048, also known as CVE-2012-3425).
 
 Version 1.6.0beta21 [April 27, 2012]
   Revised scripts/makefile.darwin: use system zlib; remove quotes around
@@ -393,6 +393,197 @@ Version 1.6.0beta25 [June 16, 2012]
     provide a list of chunks to be processed instead of a list of chunks to
     ignore.  Revised contrib/gregbook/readpng2.c accordingly.
 
+Version 1.6.0beta26 [July 10, 2012]
+  Removed scripts/makefile.cegcc from the *.zip and *.7z distributions; it
+    depends on configure, which is not included in those archives.
+  Moved scripts/chkfmt to contrib/tools.
+  Changed "a+w" to "u+w" in Makefile.in to fix CVE-2012-3386.
+
+Version 1.6.0beta27 [August 11, 2012]
+  Do not compile PNG_DEPRECATED, PNG_ALLOC and PNG_PRIVATE when __GNUC__ < 3.
+  Do not use __restrict when GNUC is <= 3.1
+  Removed references to png_zalloc() and png_zfree() from the manual.
+  Fixed configurations where floating point is completely disabled.  Because
+    of the changes to support symbol prefixing PNG_INTERNAL_FUNCTION declares
+    floating point APIs during libpng builds even if they are completely
+    disabled. This requires the png floating point types (png_double*) to be
+    declared even though the functions are never actually defined.  This
+    change provides a dummy definition so that the declarations work, yet any
+    implementation will fail to compile because of an incomplete type.
+  Re-eliminated the use of strcpy() in pngtest.c.  An unncessary use of
+    strcpy() was accidentally re-introduced in libpng16; this change replaces
+    it with strncpy().
+  Eliminated use of png_sizeof(); use sizeof() instead.
+  Use a consistent style for (sizeof type) and (sizeof (array))
+  Cleanup of png_set_filler().  This function does very different things on
+    read and write.  In libpng 1.6 the two cases can be distinguished and
+    considerable code cleanup, and extra error checking, is possible.  This
+    makes calls on the write side that have no effect be ignored with a
+    png_app_error(), which can be disabled in the app using
+    png_set_benign_errors(), and removes the spurious use of usr_channels
+    on the read side.
+  Insist on autotools 1.12.1 for git builds because there are security issues
+    with 1.12 and insisting on anything less would allow 1.12 to be used.
+  Removed info_ptr->signature[8] from WRITE-only builds.
+  Add some conditions for compiling png_fixed().  This is a small function
+    but it requires "-lm" on some platforms.
+  Cause pngtest --strict to fail on any warning from libpng (not just errors)
+    and cause it not to fail at the comparison step if libpng lacks support
+    for writing chunks that it reads from the input (currently only implemented
+    for compressed text chunks).
+  Make all three "make check" test programs work without READ or WRITE support.
+    Now "make check" will succeed even if libpng is compiled with -DPNG_NO_READ
+    or -DPNG_NO_WRITE.  The tests performed are reduced, but the basic reading
+    and writing of a PNG file is always tested by one or more of the tests.
+  Consistently use strlen(), memset(), memcpy(), and memcmp() instead of the
+    png_strlen(), png_memset(), png_memcpy(), and png_memcmp() macros.
+  Removed the png_sizeof(), png_strlen(), png_memset(), png_memcpy(), and
+    png_memcmp() macros.
+  Work around gcc 3.x and Microsoft Visual Studio 2010 complaints. Both object
+    to the split initialization of num_chunks.
+
+Version 1.6.0beta28 [August 29, 2012]
+  Unknown handling fixes and clean up. This adds more correct option
+    control of the unknown handling, corrects the pre-existing bug where
+    the per-chunk 'keep' setting is ignored and makes it possible to skip
+    IDAT chunks in the sequential reader (broken in earlier 1.6 versions).
+    There is a new test program, test-unknown.c, which is a work in progress
+    (not currently part of the test suite).  Comments in the header files now
+    explain how the unknown handling works.
+  Allow fine grain control of unknown chunk APIs. This change allows
+    png_set_keep_unknown_chunks() to be turned off if not required and causes
+    both read and write to behave appropriately (on read this is only possible
+    if the user callback is used to handle unknown chunks).  The change
+    also removes the support for storing unknown chunks in the info_struct
+    if the only unknown handling enabled is via the callback, allowing libpng
+    to be configured with callback reading and none of the unnecessary code.
+  Corrected fix for unknown handling in pngtest. This reinstates the
+    libpng handling of unknown chunks other than vpAg and sTER (including
+    unsafe-to-copy chunks which were dropped before) and eliminates the
+    repositioning of vpAg and sTER in pngtest.png by changing pngtest.png
+    (so the chunks are where libpng would put them).
+  Added "tunknown" test and corrected a logic error in png_handle_unknown()
+    when SAVE support is absent.  Moved the shell test scripts for
+    contrib/libtests from the libpng top directory to contrib/libtests.
+    png_handle_unknown() must always read or skip the chunk, if
+    SAVE_UNKNOWN_CHUNKS is turned off *and* the application does not set
+    a user callback an unknown chunk will not be read, leading to a read
+    error, which was revealed by the "tunknown" test.
+  Cleaned up and corrected ICC profile handling.
+    contrib/libtests/makepng: corrected 'rgb' and 'gray' cases.  profile_error
+    messages could be truncated; made a correct buffer size calculation and
+    adjusted pngerror.c appropriately. png_icc_check_* checking improved;
+    changed the functions to receive the correct color type of the PNG on read
+    or write and check that it matches the color space of the profile (despite
+    what the comments said before, there is danger in assuming the app will
+    cope correctly with an RGB profile on a grayscale image and, since it
+    violates the PNG spec, allowing it is certain to produce inconsistent
+    app behavior and might even cause app crashes.) Check that profiles
+    contain the tags needed to process the PNG (tags all required by the ICC
+    spec). Removed unused PNG_STATIC from pngpriv.h.
+
+Version 1.6.0beta29 [September 4, 2012]
+  Fixed the simplified API example programs and improved the error message
+    if the version field is not set.
+  Added contrib/examples/* to the *.zip and *.7z distributions.
+  Updated simplified API synopses and description of the png_image structure
+    in the manual.
+  Made makepng and pngtest produce identical PNGs, add "--relaxed" option
+    to pngtest. The "--relaxed" option turns off the benign errors that are
+    enabled by default in pre-RC builds. makepng can now write ICC profiles
+    where the length has not been extended to a multiple of 4, and pngtest
+    now intercepts all libpng errors, allowing the previously-introduced
+    "--strict test" on no warnings to actually work.
+  Improved ICC profile handling including cHRM chunk generation and fixed
+    Cygwin+MSVC build errors. The ICC profile handling now includes more
+    checking.  Several errors that caused rejection of the profile are now
+    handled with a warning in such a way that the invalid profiles will be
+    read by default in release (but not pre-RC) builds but will not be
+    written by default.  The easy part of handling the cHRM chunk is written,
+    where the ICC profile contains the required data.  The more difficult
+    part plus guessing a gAMA value requires code to pass selected RGB values
+    through the profile.
+
+Version 1.6.0beta30 [October 24, 2012]
+  Changed ICC profile matrix/vector types to not depend on array type rules.
+    By the ANSI-C standard the new types should be identical to the previous
+    versions, and all known versions of gcc tested with the previous versions
+    except for GCC-4.2.1 work with this version.  The change makes the ANSI-C
+    rule that const applied to an array of elements applies instead to the
+    elements in the array moot by explicitly applying const to the base
+    elements of the png_icc_matrix and png_icc_vector types. The accidental
+    (harmless) 'const' previously applied to the parameters of two of the
+    functions have also been removed.
+  Added a work around for GCC 4.2 optimization bug.
+  Marked the broken (bad white point) original HP sRGB profiles correctly and
+    correct comments.
+  Added -DZ_SOLO to contrib/pngminim/*/makefile to work with zlib-1.2.7
+  Use /MDd for vstudio debug builds. Also added pngunkown to the vstudio
+    builds, fixed build errors and corrected a minor exit code error in
+    pngvalid if the 'touch' file name is invalid.
+  Add updated WARNING file to projects/vstudio from libpng 1.5/vstudio
+  Fixed build when using #define PNG_NO_READ_GAMMA in png_do_compose() in
+    pngrtran.c (Domani Hannes).
+
+Version 1.6.0beta31 [November 1, 2012]
+  Undid the erroneous change to vstudio/pngvalid build in libpng-1.6.0beta30.
+  Made pngvalid so that it will build outside the libpng source tree.
+  Made builds -DPNG_NO_READ_GAMMA compile (the unit tests still fail).
+  Made PNG_NO_READ_GAMMA switch off interfaces that depend on READ_GAMMA.
+    Prior to 1.6.0 switching off READ_GAMMA did unpredictable things to the
+    interfaces that use it (specifically, png_do_background in 1.4 would
+    simply display composite for grayscale images but do composition
+    with the incorrect arithmetic for color ones). In 1.6 the semantic
+    of -DPNG_NO_READ_GAMMA is changed to simply disable any interface that
+    depends on it; this obliges people who set it to consider whether they
+    really want it off if they happen to use any of the interfaces in
+    question (typically most users who disable it won't).
+  Fixed GUIDs in projects/vstudio. Some were duplicated or missing,
+    resulting in VS2010 having to update the files.
+  Removed non-working ICC profile support code that was mostly added to
+    libpng-1.6.0beta29 and beta30. There was too much code for too little
+    gain; implementing full ICC color correction may be desireable but is left
+    up to applications.
+
+Version 1.6.0beta32 [November 25, 2012]
+  Fixed an intermittent SEGV in pngstest due to an uninitialized array element.
+  Added the ability for contrib/libtests/makepng.c to make a PNG with just one
+    color. This is useful for debugging pngstest color inaccuracy reports.
+  Fixed error checking in the simplified write API (Olaf van der Spek)
+  Made png_user_version_check() ok to use with libpng version 1.10.x and later.
+
+Version 1.6.0beta33 [December 15, 2012]
+  Fixed typo in png.c (PNG_SET_CHUNK_MALLOC_MAX should be PNG_CHUNK_MALLOC_MAX)
+    that causes the MALLOC_MAX limit not to work (John Bowler)
+  Change png_warning() to png_app_error() in pngwrite.c and comment the
+    fall-through condition.
+  Change png_warning() to png_app_warning() in png_write_tRNS().
+  Rearranged the ARM-NEON optimizations: Isolated the machine specific code
+    to the hardware subdirectory and added comments to pngrutil.c so that
+    implementors of other optimizations know what to do.
+  Fixed cases of unquoted DESTDIR in Makefile.am
+  Rebuilt Makefile.in, configure, etc., with autoconf-2.69 and automake-1.12.5.
+
+Version 1.6.0beta34 [December 19, 2012]
+  Cleaned up whitespace in the synopsis portion of the manpage "libpng.3"
+  Disassembled the version number in scripts/options.awk (necessary for
+    building on SunOs).
+
+Version 1.6.0beta35 [December 22, 2012]
+  Made default Zlib compression settings be configurable. This adds #defines to
+    pnglibconf.h to control the defaults.
+  Fixed Windows build issues, enabled ARM compilation. Various warnings issued
+    by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old
+    GCCs.) ARM support is enabled by default in zlib.props (unsupported by
+    Microsoft) and ARM compilation is made possible by deleting the check for
+    x86. The test programs cannot be run because they are not signed.
+
+  ===========================================================================
+                       NOTICE November 17, 2012:
+     The location of the git repository at SourceForge has changed.
+               Visit http://libpng.sf.net/ for details.
+  ===========================================================================
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CHANGES

@@ -4100,7 +4100,7 @@ Version 1.6.0beta20 [March 29, 2012]
     iCCP profile over writing the sRGB chunk, controlled by the
     PNG_sRGB_PROFILE_CHECKS option.
   Revised png_set_text_2() to avoid potential memory corruption (fixes
-    CVE-2011-3048).
+    CVE-2011-3048, also known as CVE-2012-3425).
 
 Version 1.6.0beta21 [April 27, 2012]
   Revised scripts/makefile.darwin: use system zlib; remove quotes around
@@ -4144,6 +4144,198 @@ Version 1.6.0beta25 [June 16, 2012]
     provide a list of chunks to be processed instead of a list of chunks to
     ignore.  Revised contrib/gregbook/readpng2.c accordingly.
 
+Version 1.6.0beta26 [July 10, 2012]
+  Removed scripts/makefile.cegcc from the *.zip and *.7z distributions; it
+    depends on configure, which is not included in those archives.
+  Moved scripts/chkfmt to contrib/tools.
+  Changed "a+w" to "u+w" in Makefile.in to fix CVE-2012-3386.
+
+Version 1.6.0beta27 [August 11, 2012]
+  Do not compile PNG_DEPRECATED, PNG_ALLOC and PNG_PRIVATE when __GNUC__ < 3.
+  Do not use __restrict when GNUC is <= 3.1
+  Removed references to png_zalloc() and png_zfree() from the manual.
+  Fixed configurations where floating point is completely disabled.  Because
+    of the changes to support symbol prefixing PNG_INTERNAL_FUNCTION declares
+    floating point APIs during libpng builds even if they are completely
+    disabled. This requires the png floating point types (png_double*) to be
+    declared even though the functions are never actually defined.  This
+    change provides a dummy definition so that the declarations work, yet any
+    implementation will fail to compile because of an incomplete type.
+  Re-eliminated the use of strcpy() in pngtest.c.  An unncessary use of
+    strcpy() was accidentally re-introduced in libpng16; this change replaces
+    it with strncpy().
+  Eliminated use of png_sizeof(); use sizeof() instead.
+  Use a consistent style for (sizeof type) and (sizeof (array))
+  Cleanup of png_set_filler().  This function does very different things on
+    read and write.  In libpng 1.6 the two cases can be distinguished and
+    considerable code cleanup, and extra error checking, is possible.  This
+    makes calls on the write side that have no effect be ignored with a
+    png_app_error(), which can be disabled in the app using
+    png_set_benign_errors(), and removes the spurious use of usr_channels
+    on the read side.
+  Insist on autotools 1.12.1 for git builds because there are security issues
+    with 1.12 and insisting on anything less would allow 1.12 to be used.
+  Removed info_ptr->signature[8] from WRITE-only builds.
+  Add some conditions for compiling png_fixed().  This is a small function
+    but it requires "-lm" on some platforms.
+  Cause pngtest --strict to fail on any warning from libpng (not just errors)
+    and cause it not to fail at the comparison step if libpng lacks support
+    for writing chunks that it reads from the input (currently only implemented
+    for compressed text chunks).
+  Make all three "make check" test programs work without READ or WRITE support.
+    Now "make check" will succeed even if libpng is compiled with -DPNG_NO_READ
+    or -DPNG_NO_WRITE.  The tests performed are reduced, but the basic reading
+    and writing of a PNG file is always tested by one or more of the tests.
+  Consistently use strlen(), memset(), memcpy(), and memcmp() instead of the
+    png_strlen(), png_memset(), png_memcpy(), and png_memcmp() macros.
+  Removed the png_sizeof(), png_strlen(), png_memset(), png_memcpy(), and
+    png_memcmp() macros.
+  Work around gcc 3.x and Microsoft Visual Studio 2010 complaints. Both object
+    to the split initialization of num_chunks.
+
+Version 1.6.0beta28 [August 29, 2012]
+  Unknown handling fixes and clean up. This adds more correct option
+    control of the unknown handling, corrects the pre-existing bug where
+    the per-chunk 'keep' setting is ignored and makes it possible to skip
+    IDAT chunks in the sequential reader (broken in earlier 1.6 versions).
+    There is a new test program, test-unknown.c, which is a work in progress
+    (not currently part of the test suite).  Comments in the header files now
+    explain how the unknown handling works.
+  Allow fine grain control of unknown chunk APIs. This change allows
+    png_set_keep_unknown_chunks() to be turned off if not required and causes
+    both read and write to behave appropriately (on read this is only possible
+    if the user callback is used to handle unknown chunks).  The change
+    also removes the support for storing unknown chunks in the info_struct
+    if the only unknown handling enabled is via the callback, allowing libpng
+    to be configured with callback reading and none of the unnecessary code.
+  Corrected fix for unknown handling in pngtest. This reinstates the
+    libpng handling of unknown chunks other than vpAg and sTER (including
+    unsafe-to-copy chunks which were dropped before) and eliminates the
+    repositioning of vpAg and sTER in pngtest.png by changing pngtest.png
+    (so the chunks are where libpng would put them).
+  Added "tunknown" test and corrected a logic error in png_handle_unknown()
+    when SAVE support is absent.  Moved the shell test scripts for
+    contrib/libtests from the libpng top directory to contrib/libtests.
+    png_handle_unknown() must always read or skip the chunk, if
+    SAVE_UNKNOWN_CHUNKS is turned off *and* the application does not set
+    a user callback an unknown chunk will not be read, leading to a read
+    error, which was revealed by the "tunknown" test.
+  Cleaned up and corrected ICC profile handling.
+    contrib/libtests/makepng: corrected 'rgb' and 'gray' cases.  profile_error
+    messages could be truncated; made a correct buffer size calculation and
+    adjusted pngerror.c appropriately. png_icc_check_* checking improved;
+    changed the functions to receive the correct color type of the PNG on read
+    or write and check that it matches the color space of the profile (despite
+    what the comments said before, there is danger in assuming the app will
+    cope correctly with an RGB profile on a grayscale image and, since it
+    violates the PNG spec, allowing it is certain to produce inconsistent
+    app behavior and might even cause app crashes.) Check that profiles
+    contain the tags needed to process the PNG (tags all required by the ICC
+    spec). Removed unused PNG_STATIC from pngpriv.h.
+
+Version 1.6.0beta29 [September 4, 2012]
+  Fixed the simplified API example programs to add the *colormap parameter
+    to several of he API and improved the error message if the version field
+    is not set.
+  Added contrib/examples/* to the *.zip and *.7z distributions.
+  Updated simplified API synopses and description of the png_image structure
+    in the manual.
+  Made makepng and pngtest produce identical PNGs, add "--relaxed" option
+    to pngtest. The "--relaxed" option turns off the benign errors that are
+    enabled by default in pre-RC builds. makepng can now write ICC profiles
+    where the length has not been extended to a multiple of 4, and pngtest
+    now intercepts all libpng errors, allowing the previously-introduced
+    "--strict test" on no warnings to actually work.
+  Improved ICC profile handling including cHRM chunk generation and fixed
+    Cygwin+MSVC build errors. The ICC profile handling now includes more
+    checking.  Several errors that caused rejection of the profile are now
+    handled with a warning in such a way that the invalid profiles will be
+    read by default in release (but not pre-RC) builds but will not be
+    written by default.  The easy part of handling the cHRM chunk is written,
+    where the ICC profile contains the required data.  The more difficult
+    part plus guessing a gAMA value requires code to pass selected RGB values
+    through the profile.
+
+Version 1.6.0beta30 [October 24, 2012]
+  Changed ICC profile matrix/vector types to not depend on array type rules.
+    By the ANSI-C standard the new types should be identical to the previous
+    versions, and all known versions of gcc tested with the previous versions
+    except for GCC-4.2.1 work with this version.  The change makes the ANSI-C
+    rule that const applied to an array of elements applies instead to the
+    elements in the array moot by explicitly applying const to the base
+    elements of the png_icc_matrix and png_icc_vector types. The accidental
+    (harmless) 'const' previously applied to the parameters of two of the
+    functions have also been removed.
+  Added a work around for GCC 4.2 optimization bug.
+  Marked the broken (bad white point) original HP sRGB profiles correctly and
+    correct comments.
+  Added -DZ_SOLO to contrib/pngminim/*/makefile to work with zlib-1.2.7
+  Use /MDd for vstudio debug builds. Also added pngunkown to the vstudio
+    builds, fixed build errors and corrected a minor exit code error in
+    pngvalid if the 'touch' file name is invalid.
+  Add updated WARNING file to projects/vstudio from libpng 1.5/vstudio
+  Fixed build when using #define PNG_NO_READ_GAMMA in png_do_compose() in
+    pngrtran.c (Domani Hannes).
+
+Version 1.6.0beta31 [November 1, 2012]
+  Undid the erroneous change to vstudio/pngvalid build in libpng-1.6.0beta30.
+  Made pngvalid so that it will build outside the libpng source tree.
+  Made builds -DPNG_NO_READ_GAMMA compile (the unit tests still fail).
+  Made PNG_NO_READ_GAMMA switch off interfaces that depend on READ_GAMMA.
+    Prior to 1.6.0 switching off READ_GAMMA did unpredictable things to the
+    interfaces that use it (specifically, png_do_background in 1.4 would
+    simply display composite for grayscale images but do composition
+    with the incorrect arithmetic for color ones). In 1.6 the semantic
+    of -DPNG_NO_READ_GAMMA is changed to simply disable any interface that
+    depends on it; this obliges people who set it to consider whether they
+    really want it off if they happen to use any of the interfaces in
+    question (typically most users who disable it won't).
+  Fixed GUIDs in projects/vstudio. Some were duplicated or missing,
+    resulting in VS2010 having to update the files.
+  Removed non-working ICC profile support code that was mostly added to
+    libpng-1.6.0beta29 and beta30. There was too much code for too little
+    gain; implementing full ICC color correction may be desireable but is left
+    up to applications.
+
+Version 1.6.0beta32 [November 25, 2012]
+  Fixed an intermittent SEGV in pngstest due to an uninitialized array element.
+  Added the ability for contrib/libtests/makepng.c to make a PNG with just one
+    color. This is useful for debugging pngstest color inaccuracy reports.
+  Fixed error checking in the simplified write API (Olaf van der Spek)
+  Made png_user_version_check() ok to use with libpng version 1.10.x and later.
+
+Version 1.6.0beta33 [December 15, 2012]
+  Fixed typo in png.c (PNG_SET_CHUNK_MALLOC_MAX should be PNG_CHUNK_MALLOC_MAX)
+    that causes the MALLOC_MAX limit not to work (John Bowler)
+  Change png_warning() to png_app_error() in pngwrite.c and comment the
+    fall-through condition.
+  Change png_warning() to png_app_warning() in png_write_tRNS().
+  Rearranged the ARM-NEON optimizations: Isolated the machine specific code
+    to the hardware subdirectory and added comments to pngrutil.c so that
+    implementors of other optimizations know what to do.
+  Fixed cases of unquoted DESTDIR in Makefile.am
+  Rebuilt Makefile.in, configure, etc., with autoconf-2.69 and automake-1.12.5.
+
+Version 1.6.0beta34 [December 19, 2012]
+  Cleaned up whitespace in the synopsis portion of the manpage "libpng.3"
+  Disassembled the version number in scripts/options.awk (necessary for
+    building on SunOs).
+
+Version 1.6.0beta35 [December 22, 2012]
+  Made default Zlib compression settings be configurable. This adds #defines to
+    pnglibconf.h to control the defaults.
+  Fixed Windows build issues, enabled ARM compilation. Various warnings issued
+    by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old
+    GCCs.) ARM support is enabled by default in zlib.props (unsupported by
+    Microsoft) and ARM compilation is made possible by deleting the check for
+    x86. The test programs cannot be run because they are not signed.
+
+  ===========================================================================
+                       NOTICE November 17, 2012:
+     The location of the git repository at SourceForge has changed.
+               Visit http://libpng.sf.net/ for details.
+  ===========================================================================
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CMakeLists.txt

@@ -260,7 +260,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.0beta25
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.0beta35
     VERSION 16.${PNGLIB_RELEASE}.0
     SOVERSION 16
     CLEAN_DIRECT_OUTPUT 1)

LICENSE

@@ -10,7 +10,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.0beta25, June 16, 2012, are
+libpng versions 1.2.6, August 15, 2004, through 1.6.0beta35, December 22, 2012, are
 Copyright (c) 2004, 2006-2012 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
@@ -108,4 +108,4 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-June 16, 2012
+December 22, 2012

Makefile.am

@@ -14,12 +14,17 @@ pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 TESTS = test-pngtest.sh
 
 # Only do the following if the contrib directory is present.
-check_PROGRAMS+= pngvalid pngstest
+check_PROGRAMS+= pngvalid pngstest pngunknown
 pngvalid_SOURCES = contrib/libtests/pngvalid.c
 pngstest_SOURCES = contrib/libtests/pngstest.c
+pngunknown_SOURCES = contrib/libtests/pngunknown.c
 pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-TESTS += test-pngvalid-simple.sh test-pngvalid-full.sh test-pngstest.sh
+pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+TESTS += contrib/libtests/test-pngunknown.sh\
+	 contrib/libtests/test-pngvalid-simple.sh\
+	 contrib/libtests/test-pngvalid-full.sh\
+	 contrib/libtests/test-pngstest.sh
 
 # man pages
 dist_man_MANS= libpng.3 libpngpf.3 png.5
@@ -38,7 +43,8 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c\
 	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa
 
 if PNG_ARM_NEON
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/filter_neon.S
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
+	arm/filter_neon.S
 endif
 
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
@@ -158,6 +164,7 @@ $(srcdir)/scripts/pnglibconf.h.prebuilt:
 # an installed one (this can happen immediately after on a clean system if
 # 'make test' is the first thing the user does.)
 contrib/libtests/pngstest.o contrib/libtests/pngvalid.o pngtest.o: pnglibconf.h
+contrib/libtests/pngunknown.o: pnglibconf.h
 
 # We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually
 # be built with PNG_USE_READ_MACROS; this prevents the read macros from
@@ -230,22 +237,24 @@ dist-hook:
 
 # install the .../include headers as links to the new ones
 install-data-hook:
-	cd $(DESTDIR)$(includedir); rm -f png.h pngconf.h pnglibconf.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/png.h png.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/pngconf.h \
+	cd '$(DESTDIR)$(includedir)'; rm -f png.h pngconf.h pnglibconf.h
+	cd '$(DESTDIR)$(includedir)'; $(LN_S) $(PNGLIB_BASENAME)/png.h png.h
+	cd '$(DESTDIR)$(includedir)'; $(LN_S) $(PNGLIB_BASENAME)/pngconf.h \
 		pngconf.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/pnglibconf.h \
+	cd '$(DESTDIR)$(includedir)'; $(LN_S) $(PNGLIB_BASENAME)/pnglibconf.h \
 		pnglibconf.h
-	cd $(DESTDIR)$(pkgconfigdir); rm -f libpng.pc
-	cd $(DESTDIR)$(pkgconfigdir); $(LN_S) $(PNGLIB_BASENAME).pc libpng.pc
+	cd '$(DESTDIR)$(pkgconfigdir)'; rm -f libpng.pc
+	cd '$(DESTDIR)$(pkgconfigdir)'; $(LN_S) $(PNGLIB_BASENAME).pc libpng.pc
 
 # do evil things to libpng to cause libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ to be used
 install-exec-hook:
-	cd $(DESTDIR)$(bindir); rm -f libpng-config
-	cd $(DESTDIR)$(bindir); $(LN_S) $(PNGLIB_BASENAME)-config libpng-config
+	cd '$(DESTDIR)$(bindir)'; rm -f libpng-config
+	cd '$(DESTDIR)$(bindir)';\
+	   $(LN_S) $(PNGLIB_BASENAME)-config libpng-config
 	@set -x;\
-	cd $(DESTDIR)$(libdir);\
-	for ext in a la so so.@PNGLIB_MAJOR@@PNGLIB_MINOR@.@PNGLIB_RELEASE@ sl dylib dll.a; do\
+	cd '$(DESTDIR)$(libdir)';\
+	for ext in a la so so.@PNGLIB_MAJOR@@PNGLIB_MINOR@.@PNGLIB_RELEASE@\
+	   sl dylib dll.a; do\
 		rm -f libpng.$$ext;\
                 if test -f $(PNGLIB_BASENAME).$$ext; then\
                        $(LN_S) $(PNGLIB_BASENAME).$$ext libpng.$$ext;\
@@ -253,9 +262,9 @@ install-exec-hook:
 	done
 
 uninstall-hook:
-	cd $(DESTDIR)$(includedir); rm -f png.h pngconf.h pnglibconf.h
-	rm -f $(DESTDIR)$(pkgconfigdir)/libpng.pc
-	rm -f $(DESTDIR)$(bindir)/libpng-config
-	rm -f $(DESTDIR)$(libdir)/libpng.a
-	rm -f $(DESTDIR)$(libdir)/libpng.la
-	rm -f $(DESTDIR)$(libdir)/libpng.dll.a
+	cd '$(DESTDIR)$(includedir)'; rm -f png.h pngconf.h pnglibconf.h
+	rm -f '$(DESTDIR)$(pkgconfigdir)/libpng.pc'
+	rm -f '$(DESTDIR)$(bindir)/libpng-config'
+	rm -f '$(DESTDIR)$(libdir)/libpng.a'
+	rm -f '$(DESTDIR)$(libdir)/libpng.la'
+	rm -f '$(DESTDIR)$(libdir)/libpng.dll.a'

README

@@ -1,4 +1,4 @@
-README for libpng version 1.6.0beta25 - June 16, 2012 (shared library 16.0)
+README for libpng version 1.6.0beta35 - December 22, 2012 (shared library 16.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.

arm/arm_init.c

@@ -0,0 +1,86 @@
+
+/* arm_init.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2012 Glenn Randers-Pehrson
+ * Written by Mans Rullgard, 2011.
+ * Last changed in libpng 1.5.14 [(PENDING RELEASE)]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include "../pngpriv.h"
+
+/* __arm__ is defined by GCC, MSVC defines _M_ARM to the ARM version number */
+#if defined __linux__ && defined __arm__
+#include <stdio.h>
+#include <elf.h>
+#include <asm/hwcap.h>
+
+static int png_have_hwcap(unsigned cap)
+{
+   FILE *f = fopen("/proc/self/auxv", "r");
+   Elf32_auxv_t aux;
+   int have_cap = 0;
+
+   if (!f)
+      return 0;
+
+   while (fread(&aux, sizeof(aux), 1, f) > 0)
+   {
+      if (aux.a_type == AT_HWCAP &&
+          aux.a_un.a_val & cap)
+      {
+         have_cap = 1;
+         break;
+      }
+   }
+
+   fclose(f);
+
+   return have_cap;
+}
+#endif /* __linux__ && __arm__ */
+
+void
+png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
+{
+#ifdef __arm__
+#ifdef __linux__
+   if (!png_have_hwcap(HWCAP_NEON))
+      return;
+#endif
+
+   /* IMPORTANT: any new external functions used here must be declared using
+    * PNG_INTERNAL_FUNCTION in ../pngpriv.h.  This is required so that the
+    * 'prefix' option to configure works:
+    *
+    *    ./configure --with-libpng-prefix=foobar_
+    *
+    * Verify you have got this right by running the above command, doing a build
+    * and examining pngprefix.h; it must contain a #define for every external
+    * function you add.  (Notice that this happens automatically for the
+    * initialization function.)
+    */
+   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
+
+   if (bpp == 3)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+         png_read_filter_row_paeth3_neon;
+   }
+
+   else if (bpp == 4)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+          png_read_filter_row_paeth4_neon;
+   }
+#else
+   PNG_UNUSED(pp)
+   PNG_UNUSED(bpp)
+#endif
+}

arm/filter_neon.S

@@ -3,12 +3,14 @@
  *
  * Copyright (c) 2011 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
+ * Last changed in libpng 1.5.7 [December 15, 2011]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  */
 
+#ifdef __arm__
 #if defined(__linux__) && defined(__ELF__)
 .section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
 #endif
@@ -223,3 +225,4 @@ func    png_read_filter_row_paeth3_neon, export=1
 
         pop             {r4,pc}
 endfunc
+#endif

configure.ac

@@ -18,15 +18,15 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.0beta25],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.0beta35],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
 # color-tests requires automake 1.11 or later
 # silent-rules requires automake 1.11 or later
 # dist-xz requires automake 1.11 or later
-# 1.11.1 fixes a security issue in 1.11
-AM_INIT_AUTOMAKE([1.11.1 foreign dist-xz dist-bzip2 color-tests silent-rules])
+# 1.12.2 fixes a security issue in 1.11.2 and 1.12.1
+AM_INIT_AUTOMAKE([1.12.2 foreign dist-xz dist-bzip2 color-tests silent-rules])
 # was:
 # AM_INIT_AUTOMAKE
 AM_MAINTAINER_MODE
@@ -37,7 +37,7 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
 
-PNGLIB_VERSION=1.6.0beta25
+PNGLIB_VERSION=1.6.0beta35
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
 PNGLIB_RELEASE=0
@@ -241,8 +241,11 @@ AC_SUBST([AM_CCASFLAGS], [-Wa,--noexecstack])
 AC_ARG_ENABLE([arm-neon],
    AS_HELP_STRING([[[--enable-arm-neon]]], [Enable ARM NEON optimizations]),
    [if test "${enableval}" = "yes"; then
-      AC_DEFINE([PNG_ARM_NEON], [1], [Enable ARM NEON optimizations])
-      AC_DEFINE([PNG_ALIGNED_MEMORY_SUPPORTED], [1], [Align row buffers])
+      AC_DEFINE([PNG_FILTER_OPTIMIZATIONS],
+                [png_init_filter_functions_neon],
+                [ARM NEON filter initialization function])
+      AC_DEFINE([PNG_ALIGNED_MEMORY_SUPPORTED], [1],
+                [Align row buffers])
     fi])
 AM_CONDITIONAL([PNG_ARM_NEON], [test "${enable_arm_neon:-no}" = yes])
 

contrib/examples/pngpixel.c

@@ -273,7 +273,7 @@ int main(int argc, const char **argv)
                            ystep = xstep = 1;
                         }
 
-                        /* To find the pixel loop over 'py' for each pass
+                        /* To find the pixel, loop over 'py' for each pass
                          * reading a row and then checking to see if it
                          * contains the pixel.
                          */
@@ -283,12 +283,13 @@ int main(int argc, const char **argv)
 
                            /* png_read_row takes two pointers.  When libpng
                             * handles the interlace the first is filled in
-                            * pixel-by-pixel, the second receives the same
+                            * pixel-by-pixel, and the second receives the same
                             * pixels but they are replicated across the
                             * unwritten pixels so far for each pass.  When we
                             * do the interlace, however, they just contain
                             * the pixels from the interlace pass - giving
-                            * both is wasteful and pointless.
+                            * both is wasteful and pointless, so we pass a
+                            * NULL pointer.
                             */
                            png_read_row(png_ptr, row_tmp, NULL);
 
@@ -326,7 +327,7 @@ int main(int argc, const char **argv)
                else
                {
                   /* Else libpng has raised an error.  An error message has
-                   * already been output, it is only necessary to clean up
+                   * already been output, so it is only necessary to clean up
                    * locally allocated data:
                    */
                   if (row != NULL)

contrib/examples/pngtopng.c

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

contrib/libtests/makepng.c

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

contrib/libtests/pngstest.c

@@ -35,6 +35,7 @@
 #  include "../../png.h"
 #endif
 
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED /* Else nothing can be done */
 #include "../tools/sRGB.h"
 
 /* KNOWN ISSUES
@@ -2624,7 +2625,7 @@ component_loc(png_byte loc[4], png_uint_32 format)
    else
    {
       channels = 1;
-      loc[0] = loc[1] = loc[2] = 0;
+      loc[1] = loc[2] = loc[3] = 0;
    }
 
    if (format & PNG_FORMAT_FLAG_ALPHA)
@@ -3152,6 +3153,7 @@ read_one_file(Image *image)
    return read_file(image, FORMAT_NO_CHANGE, NULL);
 }
 
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
 static int
 write_one_file(Image *output, Image *image, int convert_to_8bit)
 {
@@ -3240,6 +3242,7 @@ write_one_file(Image *output, Image *image, int convert_to_8bit)
       return logerror(output, output->tmpfile_name,
          ": read of new file failed", "");
 }
+#endif
 
 static int
 testimage(Image *image, png_uint_32 opts, format_list *pf)
@@ -3327,44 +3330,48 @@ testimage(Image *image, png_uint_32 opts, format_list *pf)
          if (!result)
             break;
 
-         /* Write the *copy* just made to a new file to make sure the write side
-          * works ok.  Check the conversion to sRGB if the copy is linear.
-          */
-         output.opts = opts;
-         result = write_one_file(&output, &copy, 0/*convert to 8bit*/);
-         if (!result)
-            break;
-
-         /* Validate against the original too; the background is needed here
-          * as well so that compare_two_images knows what color was used.
-          */
-         result = compare_two_images(image, &output, 0, background);
-         if (!result)
-            break;
-
-         if ((format & PNG_FORMAT_FLAG_LINEAR) != 0 &&
-            (format & PNG_FORMAT_FLAG_COLORMAP) == 0)
-         {
-            /* 'output' is linear, convert to the corresponding sRGB format. */
-            output.opts = opts;
-            result = write_one_file(&output, &copy, 1/*convert to 8bit*/);
-            if (!result)
-               break;
-
-            /* This may involve a conversion via linear; in the ideal world this
-             * would round-trip correctly, but libpng 1.5.7 is not the ideal
-             * world so allow a drift (error_via_linear).
-             *
-             * 'image' has an alpha channel but 'output' does not then there
-             * will a strip-alpha-channel operation (because 'output' is
-             * linear), handle this by composing on black when doing the
-             * comparison.
+#        ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+            /* Write the *copy* just made to a new file to make sure the write
+             * side works ok.  Check the conversion to sRGB if the copy is
+             * linear.
              */
-            result = compare_two_images(image, &output, 1/*via_linear*/,
-               background);
+            output.opts = opts;
+            result = write_one_file(&output, &copy, 0/*convert to 8bit*/);
             if (!result)
                break;
-         }
+
+            /* Validate against the original too; the background is needed here
+             * as well so that compare_two_images knows what color was used.
+             */
+            result = compare_two_images(image, &output, 0, background);
+            if (!result)
+               break;
+
+            if ((format & PNG_FORMAT_FLAG_LINEAR) != 0 &&
+               (format & PNG_FORMAT_FLAG_COLORMAP) == 0)
+            {
+               /* 'output' is linear, convert to the corresponding sRGB format.
+                */
+               output.opts = opts;
+               result = write_one_file(&output, &copy, 1/*convert to 8bit*/);
+               if (!result)
+                  break;
+
+               /* This may involve a conversion via linear; in the ideal world
+                * this would round-trip correctly, but libpng 1.5.7 is not the
+                * ideal world so allow a drift (error_via_linear).
+                *
+                * 'image' has an alpha channel but 'output' does not then there
+                * will a strip-alpha-channel operation (because 'output' is
+                * linear), handle this by composing on black when doing the
+                * comparison.
+                */
+               result = compare_two_images(image, &output, 1/*via_linear*/,
+                  background);
+               if (!result)
+                  break;
+            }
+#        endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */
       }
 
       freeimage(&output);
@@ -3400,6 +3407,10 @@ test_one_file(const char *file_name, format_list *formats, png_uint_32 opts,
       else
          printf("FAIL:");
 
+#     ifndef PNG_SIMPLIFIED_WRITE_SUPPORTED
+         printf(" (no write)");
+#     endif
+
       print_opts(opts);
       printf(" %s\n", file_name);
       /* stdout may not be line-buffered if it is piped to a file, so: */
@@ -3679,3 +3690,11 @@ main(int argc, char **argv)
 
    return retval;
 }
+
+#else /* !PNG_SIMPLIFIED_READ_SUPPORTED */
+int main(void)
+{
+   fprintf(stderr, "pngstest: no read support in libpng, test skipped\n");
+   return 0;
+}
+#endif /* PNG_SIMPLIFIED_READ_SUPPORTED */

contrib/libtests/pngunknown.c

@@ -0,0 +1,960 @@
+
+/* pngunknown.c - test the read side unknown chunk handling
+ *
+ * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
+ * Copyright (c) 2012 Glenn Randers-Pehrson
+ * Written by John Cunningham Bowler
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * NOTES:
+ *   This is a C program that is intended to be linked against libpng.  It
+ *   allows the libpng unknown handling code to be tested by interpreting
+ *   arguments to save or discard combinations of chunks.  The program is
+ *   currently just a minimal validation for the built-in libpng facilities.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <setjmp.h>
+
+/* Define the following to use this test against your installed libpng, rather
+ * than the one being built here:
+ */
+#ifdef PNG_FREESTANDING_TESTS
+#  include <png.h>
+#else
+#  include "../../png.h"
+#endif
+
+#ifdef PNG_READ_SUPPORTED
+
+#if PNG_LIBPNG_VER < 10500
+/* This deliberately lacks the PNG_CONST. */
+typedef png_byte *png_const_bytep;
+
+/* This is copied from 1.5.1 png.h: */
+#define PNG_INTERLACE_ADAM7_PASSES 7
+#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7)
+#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7)
+#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
+#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
+#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
+   -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
+#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
+   -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
+#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
+   (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
+#define PNG_COL_FROM_PASS_COL(xIn, pass) \
+   (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
+#define PNG_PASS_MASK(pass,off) ( \
+   ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \
+   ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U))
+#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
+   ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
+#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
+   ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
+
+/* These are needed too for the default build: */
+#define PNG_WRITE_16BIT_SUPPORTED
+#define PNG_READ_16BIT_SUPPORTED
+
+/* This comes from pnglibconf.h afer 1.5: */
+#define PNG_FP_1 100000
+#define PNG_GAMMA_THRESHOLD_FIXED\
+   ((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1))
+#endif
+
+#if PNG_LIBPNG_VER < 10600
+   /* 1.6.0 constifies many APIs. The following exists to allow pngvalid to be
+    * compiled against earlier versions.
+    */
+#  define png_const_structp png_structp
+#endif
+
+
+/* Copied from pngpriv.h */
+#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)
+#define png_vpAg PNG_CHUNK('v', 'p', 'A', 'g')
+
+/* Test on flag values as defined in the spec (section 5.4): */
+#define PNG_CHUNK_ANCILLARY(c )   (1 & ((c) >> 29))
+#define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLARY(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))
+
+/* Chunk information */
+#define PNG_INFO_tEXt 0x10000000U
+#define PNG_INFO_iTXt 0x20000000U
+#define PNG_INFO_zTXt 0x40000000U
+
+#define PNG_INFO_sTER 0x01000000U
+#define PNG_INFO_vpAg 0x02000000U
+
+#define ABSENT  0
+#define START   1
+#define END     2
+
+static struct
+{
+   char        name[5];
+   png_uint_32 flag;
+   png_uint_32 tag;
+   int         unknown;    /* Chunk not known to libpng */
+   int         all;        /* Chunk set by the '-1' option */
+   int         position;   /* position in pngtest.png */
+   int         keep;       /* unknown handling setting */
+} chunk_info[] = {
+   /* Critical chunks */
+   { "IDAT", PNG_INFO_IDAT, png_IDAT, 0, 0,  START, 0 }, /* must be [0] */
+   { "PLTE", PNG_INFO_PLTE, png_PLTE, 0, 0, ABSENT, 0 },
+
+   /* Non-critical chunks that libpng handles */
+   { "bKGD", PNG_INFO_bKGD, png_bKGD, 0, 1,  START, 0 },
+   { "cHRM", PNG_INFO_cHRM, png_cHRM, 0, 1,  START, 0 },
+   { "gAMA", PNG_INFO_gAMA, png_gAMA, 0, 1,  START, 0 },
+   { "hIST", PNG_INFO_hIST, png_hIST, 0, 1, ABSENT, 0 },
+   { "iCCP", PNG_INFO_iCCP, png_iCCP, 0, 1, ABSENT, 0 },
+   { "iTXt", PNG_INFO_iTXt, png_iTXt, 0, 1, ABSENT, 0 },
+   { "oFFs", PNG_INFO_oFFs, png_oFFs, 0, 1,  START, 0 },
+   { "pCAL", PNG_INFO_pCAL, png_pCAL, 0, 1,  START, 0 },
+   { "pHYs", PNG_INFO_pHYs, png_pHYs, 0, 1,  START, 0 },
+   { "sBIT", PNG_INFO_sBIT, png_sBIT, 0, 1,  START, 0 },
+   { "sCAL", PNG_INFO_sCAL, png_sCAL, 0, 1,  START, 0 },
+   { "sPLT", PNG_INFO_sPLT, png_sPLT, 0, 1, ABSENT, 0 },
+   { "sRGB", PNG_INFO_sRGB, png_sRGB, 0, 1,  START, 0 },
+   { "tEXt", PNG_INFO_tEXt, png_tEXt, 0, 1,  START, 0 },
+   { "tIME", PNG_INFO_tIME, png_tIME, 0, 1,  START, 0 },
+   { "tRNS", PNG_INFO_tRNS, png_tRNS, 0, 0, ABSENT, 0 },
+   { "zTXt", PNG_INFO_zTXt, png_zTXt, 0, 1,    END, 0 },
+
+   /* No libpng handling */
+   { "sTER", PNG_INFO_sTER, png_sTER, 1, 1,  START, 0 },
+   { "vpAg", PNG_INFO_vpAg, png_vpAg, 1, 0,  START, 0 },
+};
+
+#define NINFO ((int)((sizeof chunk_info)/(sizeof chunk_info[0])))
+
+static void
+clear_keep(void)
+{
+   int i = NINFO;
+   while (--i >= 0)
+      chunk_info[i].keep = 0;
+}
+
+static int
+find(const char *name)
+{
+   int i = NINFO;
+   while (--i >= 0)
+   {
+      if (memcmp(chunk_info[i].name, name, 4) == 0)
+         break;
+   }
+
+   return i;
+}
+
+static int
+findb(const png_byte *name)
+{
+   int i = NINFO;
+   while (--i >= 0)
+   {
+      if (memcmp(chunk_info[i].name, name, 4) == 0)
+         break;
+   }
+
+   return i;
+}
+
+static int
+find_by_flag(png_uint_32 flag)
+{
+   int i = NINFO;
+
+   while (--i >= 0) if (chunk_info[i].flag == flag) return i;
+
+   fprintf(stderr, "pngunknown: internal error\n");
+   exit(4);
+}
+
+static int
+ancillary(const char *name)
+{
+   return PNG_CHUNK_ANCILLARY(PNG_CHUNK(name[0], name[1], name[2], name[3]));
+}
+
+static int
+ancillaryb(const png_byte *name)
+{
+   return PNG_CHUNK_ANCILLARY(PNG_CHUNK(name[0], name[1], name[2], name[3]));
+}
+
+/* Type of an error_ptr */
+typedef struct
+{
+   jmp_buf     error_return;
+   png_structp png_ptr;
+   png_infop   info_ptr, end_ptr;
+   int         error_count;
+   int         warning_count;
+   const char *program;
+   const char *file;
+   const char *test;
+} display;
+
+static const char init[] = "initialization";
+static const char cmd[] = "command line";
+
+static void
+init_display(display *d, const char *program)
+{
+   memset(d, 0, sizeof *d);
+   d->png_ptr = NULL;
+   d->info_ptr = d->end_ptr = NULL;
+   d->error_count = d->warning_count = 0;
+   d->program = program;
+   d->file = program;
+   d->test = init;
+}
+
+static void
+clean_display(display *d)
+{
+   png_destroy_read_struct(&d->png_ptr, &d->info_ptr, &d->end_ptr);
+
+   /* This must not happen - it might cause an app crash */
+   if (d->png_ptr != NULL || d->info_ptr != NULL || d->end_ptr != NULL)
+   {
+      fprintf(stderr, "%s(%s): png_destroy_read_struct error\n", d->file,
+         d->test);
+      exit(1);
+   }
+
+   /* Invalidate the test */
+   d->test = init;
+}
+
+PNG_FUNCTION(void, display_exit, (display *d), static PNG_NORETURN)
+{
+   ++(d->error_count);
+
+   if (d->png_ptr != NULL)
+      clean_display(d);
+
+   /* During initialization and if this is a single command line argument set
+    * exit now - there is only one test, otherwise longjmp to do the next test.
+    */
+   if (d->test == init || d->test == cmd)
+      exit(1);
+
+   longjmp(d->error_return, 1);
+}
+
+static int
+display_rc(const display *d, int strict)
+{
+   return d->error_count + (strict ? d->warning_count : 0);
+}
+
+/* libpng error and warning callbacks */
+PNG_FUNCTION(void, error, (png_structp png_ptr, const char *message),
+   static PNG_NORETURN)
+{
+   display *d = (display*)png_get_error_ptr(png_ptr);
+
+   fprintf(stderr, "%s(%s): libpng error: %s\n", d->file, d->test, message);
+   display_exit(d);
+}
+
+static void
+warning(png_structp png_ptr, const char *message)
+{
+   display *d = (display*)png_get_error_ptr(png_ptr);
+
+   fprintf(stderr, "%s(%s): libpng warning: %s\n", d->file, d->test, message);
+   ++(d->warning_count);
+}
+
+static png_uint_32
+get_valid(display *d, png_const_infop info_ptr)
+{
+   png_uint_32 flags = png_get_valid(d->png_ptr, info_ptr, (png_uint_32)~0);
+
+   /* Map the text chunks back into the flags */
+   {
+      png_textp text;
+      png_uint_32 ntext = png_get_text(d->png_ptr, info_ptr, &text, NULL);
+
+      while (ntext-- > 0) switch (text[ntext].compression)
+      {
+         case -1:
+            flags |= PNG_INFO_tEXt;
+            break;
+         case 0:
+            flags |= PNG_INFO_zTXt;
+            break;
+         case 1:
+         case 2:
+            flags |= PNG_INFO_iTXt;
+            break;
+         default:
+            fprintf(stderr, "%s(%s): unknown text compression %d\n", d->file,
+               d->test, text[ntext].compression);
+            display_exit(d);
+      }
+   }
+
+   return flags;
+}
+
+static png_uint_32
+get_unknown(display *d, int def, png_const_infop info_ptr)
+{
+   /* Create corresponding 'unknown' flags */
+   png_uint_32 flags = 0;
+   {
+      png_unknown_chunkp unknown;
+      int num_unknown = png_get_unknown_chunks(d->png_ptr, info_ptr, &unknown);
+
+      while (--num_unknown >= 0)
+      {
+         int chunk = findb(unknown[num_unknown].name);
+
+         /* Chunks not known to pngunknown must be validated here; since they
+          * must also be unknown to libpng the 'def' behavior should have been
+          * used.
+          */
+         if (chunk < 0) switch (def)
+         {
+            default: /* impossible */
+            case PNG_HANDLE_CHUNK_AS_DEFAULT:
+            case PNG_HANDLE_CHUNK_NEVER:
+               fprintf(stderr, "%s(%s): %s: %s: unknown chunk saved\n",
+                  d->file, d->test, def ? "discard" : "default",
+                  unknown[num_unknown].name);
+               ++(d->error_count);
+               break;
+
+            case PNG_HANDLE_CHUNK_IF_SAFE:
+               if (!ancillaryb(unknown[num_unknown].name))
+               {
+                  fprintf(stderr,
+                     "%s(%s): if-safe: %s: unknown critical chunk saved\n",
+                     d->file, d->test, unknown[num_unknown].name);
+                  ++(d->error_count);
+                  break;
+               }
+               /* FALL THROUGH (safe) */
+            case PNG_HANDLE_CHUNK_ALWAYS:
+               break;
+         }
+
+         else
+            flags |= chunk_info[chunk].flag;
+      }
+   }
+
+   return flags;
+}
+
+static int
+check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
+   display *d)
+{
+   int i, def = PNG_HANDLE_CHUNK_AS_DEFAULT, npasses, ipass;
+   png_uint_32 height;
+
+   /* Some of these errors are permanently fatal and cause an exit here, others
+    * are per-test and cause an error return.
+    */
+   d->png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, d, error,
+      warning);
+   if (d->png_ptr == NULL)
+   {
+      fprintf(stderr, "%s(%s): could not allocate png struct\n", d->file,
+         d->test);
+      /* Terminate here, this error is not test specific. */
+      exit(1);
+   }
+
+   d->info_ptr = png_create_info_struct(d->png_ptr);
+   d->end_ptr = png_create_info_struct(d->png_ptr);
+   if (d->info_ptr == NULL || d->end_ptr == NULL)
+   {
+      fprintf(stderr, "%s(%s): could not allocate png info\n", d->file,
+         d->test);
+      clean_display(d);
+      exit(1);
+   }
+
+   png_init_io(d->png_ptr, fp);
+
+   /* Handle each argument in turn; multiple settings are possible for the same
+    * chunk and multiple calls will occur (the last one should override all
+    * preceding ones).
+    */
+   for (i=0; i<argc; ++i)
+   {
+      const char *equals = strchr(argv[i], '=');
+
+      if (equals != NULL)
+      {
+         int chunk, option;
+
+         if (strcmp(equals+1, "default") == 0)
+            option = PNG_HANDLE_CHUNK_AS_DEFAULT;
+         else if (strcmp(equals+1, "discard") == 0)
+            option = PNG_HANDLE_CHUNK_NEVER;
+         else if (strcmp(equals+1, "if-safe") == 0)
+            option = PNG_HANDLE_CHUNK_IF_SAFE;
+         else if (strcmp(equals+1, "save") == 0)
+            option = PNG_HANDLE_CHUNK_ALWAYS;
+         else
+         {
+            fprintf(stderr, "%s(%s): %s: unrecognized chunk option\n", d->file,
+               d->test, argv[i]);
+            display_exit(d);
+         }
+
+         switch (equals - argv[i])
+         {
+            case 4: /* chunk name */
+               chunk = find(argv[i]);
+
+               if (chunk >= 0)
+               {
+                  /* These #if tests have the effect of skipping the arguments
+                   * if SAVE support is unavailable - we can't do a useful test
+                   * in this case, so we just check the arguments!  This could
+                   * be improved in the future by using the read callback.
+                   */
+#                 ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+                     png_byte name[5];
+
+                     memcpy(name, chunk_info[chunk].name, 5);
+                     png_set_keep_unknown_chunks(d->png_ptr, option, name, 1);
+                     chunk_info[chunk].keep = option;
+#                 endif
+                  continue;
+               }
+
+               break;
+
+            case 7: /* default */
+               if (memcmp(argv[i], "default", 7) == 0)
+               {
+#                 ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+                     png_set_keep_unknown_chunks(d->png_ptr, option, NULL, 0);
+#                 endif
+                  def = option;
+                  continue;
+               }
+
+               break;
+
+            case 3: /* all */
+               if (memcmp(argv[i], "all", 3) == 0)
+               {
+#                 ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+                     png_set_keep_unknown_chunks(d->png_ptr, option, NULL, -1);
+                     def = option;
+
+                     for (chunk = 0; chunk < NINFO; ++chunk)
+                        if (chunk_info[chunk].all)
+                           chunk_info[chunk].keep = option;
+#                 endif
+                  continue;
+               }
+
+               break;
+
+            default: /* some misplaced = */
+
+               break;
+         }
+      }
+
+      fprintf(stderr, "%s(%s): %s: unrecognized chunk argument\n", d->file,
+         d->test, argv[i]);
+      display_exit(d);
+   }
+
+   png_read_info(d->png_ptr, d->info_ptr);
+
+   switch (png_get_interlace_type(d->png_ptr, d->info_ptr))
+   {
+      case PNG_INTERLACE_NONE:
+         npasses = 1;
+         break;
+
+      case PNG_INTERLACE_ADAM7:
+         npasses = PNG_INTERLACE_ADAM7_PASSES;
+         break;
+
+      default:
+         /* Hard error because it is not test specific */
+         fprintf(stderr, "%s(%s): invalid interlace type\n", d->file, d->test);
+         clean_display(d);
+         exit(1);
+   }
+
+   /* Skip the image data, if IDAT is not being handled then don't do this
+    * because it will cause a CRC error.
+    */
+   if (chunk_info[0/*IDAT*/].keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
+   {
+      png_start_read_image(d->png_ptr);
+      height = png_get_image_height(d->png_ptr, d->info_ptr);
+
+      if (npasses > 1)
+      {
+         png_uint_32 width = png_get_image_width(d->png_ptr, d->info_ptr);
+
+         for (ipass=0; ipass<npasses; ++ipass)
+         {
+            png_uint_32 wPass = PNG_PASS_COLS(width, ipass);
+
+            if (wPass > 0)
+            {
+               png_uint_32 y;
+
+               for (y=0; y<height; ++y) if (PNG_ROW_IN_INTERLACE_PASS(y, ipass))
+                  png_read_row(d->png_ptr, NULL, NULL);
+            }
+         }
+      } /* interlaced */
+
+      else /* not interlaced */
+      {
+         png_uint_32 y;
+
+         for (y=0; y<height; ++y)
+            png_read_row(d->png_ptr, NULL, NULL);
+      }
+   }
+
+   png_read_end(d->png_ptr, d->end_ptr);
+
+   flags[0] = get_valid(d, d->info_ptr);
+   flags[1] = get_unknown(d, def, d->info_ptr);
+
+   /* Only png_read_png sets PNG_INFO_IDAT! */
+   flags[chunk_info[0/*IDAT*/].keep != PNG_HANDLE_CHUNK_AS_DEFAULT] |=
+      PNG_INFO_IDAT;
+
+   flags[2] = get_valid(d, d->end_ptr);
+   flags[3] = get_unknown(d, def, d->end_ptr);
+
+   clean_display(d);
+
+   return def;
+}
+
+static void
+check_error(display *d, png_uint_32 flags, const char *message)
+{
+   while (flags)
+   {
+      png_uint_32 flag = flags & -(png_int_32)flags;
+      int i = find_by_flag(flag);
+
+      fprintf(stderr, "%s(%s): chunk %s: %s\n", d->file, d->test,
+         chunk_info[i].name, message);
+      ++(d->error_count);
+
+      flags &= ~flag;
+   }
+}
+
+static void
+check_handling(display *d, int def, png_uint_32 chunks, png_uint_32 known,
+   png_uint_32 unknown, const char *position)
+{
+   while (chunks)
+   {
+      png_uint_32 flag = chunks & -(png_int_32)chunks;
+      int i = find_by_flag(flag);
+      int keep = chunk_info[i].keep;
+      const char *type;
+      const char *errorx = NULL;
+
+      if (chunk_info[i].unknown)
+      {
+         if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
+         {
+            type = "UNKNOWN (default)";
+            keep = def;
+         }
+
+         else
+            type = "UNKNOWN (specified)";
+
+         if (flag & known)
+            errorx = "chunk processed";
+
+         else switch (keep)
+         {
+            case PNG_HANDLE_CHUNK_AS_DEFAULT:
+               if (flag & unknown)
+                  errorx = "DEFAULT: unknown chunk saved";
+               break;
+
+            case PNG_HANDLE_CHUNK_NEVER:
+               if (flag & unknown)
+                  errorx = "DISCARD: unknown chunk saved";
+               break;
+
+            case PNG_HANDLE_CHUNK_IF_SAFE:
+               if (ancillary(chunk_info[i].name))
+               {
+                  if (!(flag & unknown))
+                     errorx = "IF-SAFE: unknown ancillary chunk lost";
+               }
+
+               else if (flag & unknown)
+                  errorx = "IF-SAFE: unknown critical chunk saved";
+               break;
+
+            case PNG_HANDLE_CHUNK_ALWAYS:
+               if (!(flag & unknown))
+                  errorx = "SAVE: unknown chunk lost";
+               break;
+
+            default:
+               errorx = "internal error: bad keep";
+               break;
+         }
+      } /* unknown chunk */
+
+      else /* known chunk */
+      {
+         type = "KNOWN";
+
+         if (flag & known)
+         {
+            /* chunk was processed, it won't have been saved because that is
+             * caught below when checking for inconsistent processing.
+             */
+            if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
+               errorx = "!DEFAULT: known chunk processed";
+         }
+
+         else /* not processed */ switch (keep)
+         {
+            case PNG_HANDLE_CHUNK_AS_DEFAULT:
+               errorx = "DEFAULT: known chunk not processed";
+               break;
+
+            case PNG_HANDLE_CHUNK_NEVER:
+               if (flag & unknown)
+                  errorx = "DISCARD: known chunk saved";
+               break;
+
+            case PNG_HANDLE_CHUNK_IF_SAFE:
+               if (ancillary(chunk_info[i].name))
+               {
+                  if (!(flag & unknown))
+                     errorx = "IF-SAFE: known ancillary chunk lost";
+               }
+
+               else if (flag & unknown)
+                  errorx = "IF-SAFE: known critical chunk saved";
+               break;
+
+            case PNG_HANDLE_CHUNK_ALWAYS:
+               if (!(flag & unknown))
+                  errorx = "SAVE: known chunk lost";
+               break;
+
+            default:
+               errorx = "internal error: bad keep (2)";
+               break;
+         }
+      }
+
+      if (errorx != NULL)
+      {
+         ++(d->error_count);
+         fprintf(stderr, "%s(%s): %s %s %s: %s\n",
+            d->file, d->test, type, chunk_info[i].name, position, errorx);
+      }
+
+      chunks &= ~flag;
+   }
+}
+
+static void
+perform_one_test(FILE *fp, int argc, const char **argv,
+   png_uint_32 *default_flags, display *d)
+{
+   int def;
+   png_uint_32 flags[2][4];
+
+   rewind(fp);
+   clear_keep();
+   memcpy(flags[0], default_flags, sizeof flags[0]);
+
+   def = check(fp, argc, argv, flags[1], d);
+
+   /* Chunks should either be known or unknown, never both and this should apply
+    * whether the chunk is before or after the IDAT (actually, the app can
+    * probably change this by swapping the handling after the image, but this
+    * test does not do that.)
+    */
+   check_error(d, (flags[0][0]|flags[0][2]) & (flags[0][1]|flags[0][3]),
+      "chunk handled inconsistently in count tests");
+   check_error(d, (flags[1][0]|flags[1][2]) & (flags[1][1]|flags[1][3]),
+      "chunk handled inconsistently in option tests");
+
+   /* Now find out what happened to each chunk before and after the IDAT and
+    * determine if the behavior was correct.  First some basic sanity checks,
+    * any known chunk should be known in the original count, any unknown chunk
+    * should be either known or unknown in the original.
+    */
+   {
+      png_uint_32 test;
+
+      test = flags[1][0] & ~flags[0][0];
+      check_error(d, test, "new known chunk before IDAT");
+      test = flags[1][1] & ~(flags[0][0] | flags[0][1]);
+      check_error(d, test, "new unknown chunk before IDAT");
+      test = flags[1][2] & ~flags[0][2];
+      check_error(d, test, "new known chunk after IDAT");
+      test = flags[1][3] & ~(flags[0][2] | flags[0][3]);
+      check_error(d, test, "new unknown chunk after IDAT");
+   }
+
+   /* Now each chunk in the original list should have been handled according to
+    * the options set for that chunk, regardless of whether libpng knows about
+    * it or not.
+    */
+   check_handling(d, def, flags[0][0] | flags[0][1], flags[1][0], flags[1][1],
+      "before IDAT");
+   check_handling(d, def, flags[0][2] | flags[0][3], flags[1][2], flags[1][3],
+      "after IDAT");
+}
+
+static void
+perform_one_test_safe(FILE *fp, int argc, const char **argv,
+   png_uint_32 *default_flags, display *d, const char *test)
+{
+   if (setjmp(d->error_return) == 0)
+   {
+      d->test = test; /* allow use of d->error_return */
+      perform_one_test(fp, argc, argv, default_flags, d);
+      d->test = init; /* prevent use of d->error_return */
+   }
+}
+
+static const char *standard_tests[] =
+{
+ "discard", "default=discard", 0,
+ "save", "default=save", 0,
+ "if-safe", "default=if-safe", 0,
+ "vpAg", "vpAg=if-safe", 0,
+ "sTER", "sTER=if-safe", 0,
+ "IDAT", "default=discard", "IDAT=save", 0,
+ "sAPI", "bKGD=save", "cHRM=save", "gAMA=save", "all=discard", "iCCP=save",
+   "sBIT=save", "sRGB=save", 0,
+ 0/*end*/
+};
+
+static PNG_NORETURN void
+usage(const char *program, const char *reason)
+{
+   fprintf(stderr, "pngunknown: %s: usage:\n %s [--strict] "
+      "--default|{(CHNK|default|all)=(default|discard|if-safe|save)} "
+      "testfile.png\n", reason, program);
+   exit(2);
+}
+
+int
+main(int argc, const char **argv)
+{
+   FILE *fp;
+   png_uint_32 default_flags[4/*valid,unknown{before,after}*/];
+   int strict = 0, default_tests = 0;
+   const char *count_argv = "default=save";
+   const char *touch_file = NULL;
+   display d;
+
+   init_display(&d, argv[0]);
+
+   while (++argv, --argc > 0)
+   {
+      if (strcmp(*argv, "--strict") == 0)
+         strict = 1;
+
+      else if (strcmp(*argv, "--default") == 0)
+         default_tests = 1;
+
+      else if (strcmp(*argv, "--touch") == 0)
+      {
+         if (argc > 1)
+            touch_file = *++argv, --argc;
+
+         else
+            usage(d.program, "--touch: missing file name");
+      }
+
+      else
+         break;
+   }
+
+   /* A file name is required, but there should be no other arguments if
+    * --default was specified.
+    */
+   if (argc <= 0)
+      usage(d.program, "missing test file");
+
+   /* GCC BUG: if (default_tests && argc != 1) triggers some weird GCC argc
+    * optimization which causes warnings with -Wstrict-overflow!
+    */
+   else if (default_tests) if (argc != 1)
+      usage(d.program, "extra arguments");
+
+#  ifndef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+      fprintf(stderr, "%s: warning: no 'save' support so arguments ignored\n",
+         d.program);
+#  endif
+
+   /* The name of the test file is the last argument; remove it. */
+   d.file = argv[--argc];
+
+   fp = fopen(d.file, "rb");
+   if (fp == NULL)
+   {
+      perror(d.file);
+      exit(2);
+   }
+
+   /* First find all the chunks, known and unknown, in the test file, a failure
+    * here aborts the whole test.
+    */
+   if (check(fp, 1, &count_argv, default_flags, &d) !=
+      PNG_HANDLE_CHUNK_ALWAYS)
+   {
+      fprintf(stderr, "%s: %s: internal error\n", d.program, d.file);
+      exit(3);
+   }
+
+   /* Now find what the various supplied options cause to change: */
+   if (!default_tests)
+   {
+      d.test = cmd; /* acts as a flag to say exit, do not longjmp */
+      perform_one_test(fp, argc, argv, default_flags, &d);
+      d.test = init;
+   }
+
+   else
+   {
+      const char **test = standard_tests;
+
+      /* Set the exit_test pointer here so we can continue after a libpng error.
+       * NOTE: this leaks memory because the png_struct data from the failing
+       * test is never freed.
+       */
+      while (*test)
+      {
+         const char *this_test = *test++;
+         const char **next = test;
+         int count = display_rc(&d, strict), new_count;
+         const char *result;
+         int arg_count = 0;
+
+         while (*next) ++next, ++arg_count;
+
+         perform_one_test_safe(fp, arg_count, test, default_flags, &d,
+            this_test);
+
+         new_count = display_rc(&d, strict);
+
+         if (new_count == count)
+            result = "PASS";
+
+         else
+            result = "FAIL";
+
+         printf("%s: %s %s\n", result, d.program, this_test);
+
+         test = next+1;
+      }
+   }
+
+   fclose(fp);
+
+   if (display_rc(&d, strict) == 0)
+   {
+      /* Success, touch the success file if appropriate */
+      if (touch_file != NULL)
+      {
+         FILE *fsuccess = fopen(touch_file, "wt");
+
+         if (fsuccess != NULL)
+         {
+            int err = 0;
+            fprintf(fsuccess, "PNG unknown tests succeeded\n");
+            fflush(fsuccess);
+            err = ferror(fsuccess);
+
+            if (fclose(fsuccess) || err)
+            {
+               fprintf(stderr, "%s: write failed\n", touch_file);
+               exit(1);
+            }
+         }
+
+         else
+         {
+            fprintf(stderr, "%s: open failed\n", touch_file);
+            exit(1);
+         }
+      }
+
+      return 0;
+   }
+
+   return 1;
+}
+
+#else
+int
+main(void)
+{
+   fprintf(stderr,
+   " test ignored because libpng was not built with unknown chunk support\n");
+   return 0;
+}
+#endif

contrib/libtests/pngvalid.c

@@ -24,6 +24,7 @@
 #define _GNU_SOURCE 1 /* For the floating point exception extension */
 
 #include <signal.h>
+#include <stdio.h>
 
 #if (defined HAVE_CONFIG_H) && !(defined PNG_NO_CONFIG_H)
 #  include <config.h>
@@ -42,6 +43,8 @@
 #  include "../../png.h"
 #endif
 
+#ifdef PNG_WRITE_SUPPORTED /* else pngvalid can do nothing */
+
 #if PNG_LIBPNG_VER < 10500
 /* This deliberately lacks the PNG_CONST. */
 typedef png_byte *png_const_bytep;
@@ -82,10 +85,10 @@ typedef png_byte *png_const_bytep;
    /* 1.6.0 constifies many APIs, the following exists to allow pngvalid to be
     * compiled against earlier versions.
     */
-#  define png_const_strutp png_structp
+#  define png_const_structp png_structp
 #endif
 
-#include "zlib.h"   /* For crc32 */
+#include <zlib.h>   /* For crc32 */
 
 #include <float.h>  /* For floating point constants */
 #include <stdlib.h> /* For malloc */
@@ -104,7 +107,11 @@ typedef png_byte *png_const_bytep;
 #endif
 
 /***************************** EXCEPTION HANDLING *****************************/
-#include "../visupng/cexcept.h"
+#ifdef PNG_FREESTANDING_TESTS
+#  include <cexcept.h>
+#else
+#  include "../visupng/cexcept.h"
+#endif
 
 #ifdef __cplusplus
 #  define this not_the_cpp_this
@@ -170,6 +177,7 @@ static PNG_CONST char *colour_types[8] =
    "grayscale with alpha", invalid, "truecolour with alpha", invalid
 };
 
+#ifdef PNG_READ_SUPPORTED
 /* Convert a double precision value to fixed point. */
 static png_fixed_point
 fix(double d)
@@ -177,12 +185,14 @@ fix(double d)
    d = floor(d * PNG_FP_1 + .5);
    return (png_fixed_point)d;
 }
+#endif /* PNG_READ_SUPPORTED */
 
 /* Generate random bytes.  This uses a boring repeatable algorithm and it
  * is implemented here so that it gives the same set of numbers on every
  * architecture.  It's a linear congruential generator (Knuth or Sedgewick
  * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and
- * Hill, "The Art of Electronics".
+ * Hill, "The Art of Electronics" (Pseudo-Random Bit Sequences and Noise
+ * Generation.)
  */
 static void
 make_random_bytes(png_uint_32* seed, void* pv, size_t size)
@@ -215,6 +225,7 @@ make_four_random_bytes(png_uint_32* seed, png_bytep bytes)
    make_random_bytes(seed, bytes, 4);
 }
 
+#ifdef PNG_READ_SUPPORTED
 static void
 randomize(void *pv, size_t size)
 {
@@ -234,6 +245,7 @@ random_mod(unsigned int max)
    return x % max; /* 0 .. max-1 */
 }
 
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
 static int
 random_choice(void)
 {
@@ -243,6 +255,8 @@ random_choice(void)
 
    return x & 1;
 }
+#endif
+#endif /* PNG_READ_SUPPORTED */
 
 /* A numeric ID based on PNG file characteristics.  The 'do_interlace' field
  * simply records whether pngvalid did the interlace itself or whether it
@@ -461,6 +475,7 @@ pixel_copy(png_bytep toBuffer, png_uint_32 toIndex,
       memmove(toBuffer+(toIndex>>3), fromBuffer+(fromIndex>>3), pixelSize>>3);
 }
 
+#ifdef PNG_READ_SUPPORTED
 /* Copy a complete row of pixels, taking into account potential partial
  * bytes at the end.
  */
@@ -526,6 +541,7 @@ pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width)
       return 1+where;
    }
 }
+#endif /* PNG_READ_SUPPORTED */
 
 /*************************** BASIC PNG FILE WRITING ***************************/
 /* A png_store takes data from the sequential writer or provides data
@@ -636,6 +652,7 @@ store_pool_mark(png_bytep mark)
    make_four_random_bytes(store_seed, mark);
 }
 
+#ifdef PNG_READ_SUPPORTED
 /* Use this for random 32 bit values; this function makes sure the result is
  * non-zero.
  */
@@ -655,6 +672,7 @@ random_32(void)
          return result;
    }
 }
+#endif /* PNG_READ_SUPPORTED */
 
 static void
 store_pool_init(png_store *ps, store_pool *pool)
@@ -860,6 +878,7 @@ store_log(png_store* ps, png_const_structp pp, png_const_charp message,
       store_verbose(ps, pp, is_error ? "error: " : "warning: ", message);
 }
 
+#ifdef PNG_READ_SUPPORTED
 /* Internal error function, called with a png_store but no libpng stuff. */
 static void
 internal_error(png_store *ps, png_const_charp message)
@@ -872,6 +891,7 @@ internal_error(png_store *ps, png_const_charp message)
       Throw ps;
    }
 }
+#endif /* PNG_READ_SUPPORTED */
 
 /* Functions to use as PNG callbacks. */
 static void
@@ -1009,6 +1029,7 @@ store_ensure_image(png_store *ps, png_const_structp pp, int nImages,
    }
 }
 
+#ifdef PNG_READ_SUPPORTED
 static void
 store_image_check(PNG_CONST png_store* ps, png_const_structp pp, int iImage)
 {
@@ -1038,6 +1059,7 @@ store_image_check(PNG_CONST png_store* ps, png_const_structp pp, int iImage)
       }
    }
 }
+#endif /* PNG_READ_SUPPORTED */
 
 static void
 store_write(png_structp ppIn, png_bytep pb, png_size_t st)
@@ -1073,6 +1095,7 @@ store_flush(png_structp ppIn)
    UNUSED(ppIn) /*DOES NOTHING*/
 }
 
+#ifdef PNG_READ_SUPPORTED
 static size_t
 store_read_buffer_size(png_store *ps)
 {
@@ -1190,6 +1213,7 @@ store_progressive_read(png_store *ps, png_structp pp, png_infop pi)
    }
    while (store_read_buffer_next(ps));
 }
+#endif /* PNG_READ_SUPPORTED */
 
 /* The caller must fill this in: */
 static store_palette_entry *
@@ -1216,6 +1240,7 @@ store_write_palette(png_store *ps, int npalette)
    return ps->palette;
 }
 
+#ifdef PNG_READ_SUPPORTED
 static store_palette_entry *
 store_current_palette(png_store *ps, int *npalette)
 {
@@ -1229,6 +1254,7 @@ store_current_palette(png_store *ps, int *npalette)
    *npalette = ps->current->npalette;
    return ps->current->palette;
 }
+#endif /* PNG_READ_SUPPORTED */
 
 /***************************** MEMORY MANAGEMENT*** ***************************/
 /* A store_memory is simply the header for an allocated block of memory.  The
@@ -1503,25 +1529,29 @@ set_store_for_write(png_store *ps, png_infopp ppi,
 }
 
 /* Cleanup when finished reading (either due to error or in the success case).
+ * This routine exists even when there is no read support to make the code
+ * tidier (avoid a mass of ifdefs) and so easier to maintain.
  */
 static void
 store_read_reset(png_store *ps)
 {
-   if (ps->pread != NULL)
-   {
-      anon_context(ps);
-
-      Try
-         png_destroy_read_struct(&ps->pread, &ps->piread, NULL);
-
-      Catch_anonymous
+#  ifdef PNG_READ_SUPPORTED
+      if (ps->pread != NULL)
       {
-         /* error already output: continue */
-      }
+         anon_context(ps);
 
-      ps->pread = NULL;
-      ps->piread = NULL;
-   }
+         Try
+            png_destroy_read_struct(&ps->pread, &ps->piread, NULL);
+
+         Catch_anonymous
+         {
+            /* error already output: continue */
+         }
+
+         ps->pread = NULL;
+         ps->piread = NULL;
+      }
+#  endif
 
    /* Always do this to be safe. */
    store_pool_delete(ps, &ps->read_memory_pool);
@@ -1532,6 +1562,7 @@ store_read_reset(png_store *ps)
    ps->validated = 0;
 }
 
+#ifdef PNG_READ_SUPPORTED
 static void
 store_read_set(png_store *ps, png_uint_32 id)
 {
@@ -1609,6 +1640,7 @@ set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id,
 
    return ps->pread;
 }
+#endif /* PNG_READ_SUPPORTED */
 
 /* The overall cleanup of a store simply calls the above then removes all the
  * saved files.  This does not delete the store itself.
@@ -1648,18 +1680,6 @@ typedef struct CIE_color
    double X, Y, Z;
 } CIE_color;
 
-static double
-chromaticity_x(CIE_color c)
-{
-   return c.X / (c.X + c.Y + c.Z);
-}
-
-static double
-chromaticity_y(CIE_color c)
-{
-   return c.Y / (c.X + c.Y + c.Z);
-}
-
 typedef struct color_encoding
 {
    /* A description of an (R,G,B) encoding of color (as defined above); this
@@ -1672,6 +1692,19 @@ typedef struct color_encoding
    CIE_color red, green, blue; /* End points */
 } color_encoding;
 
+#ifdef PNG_READ_SUPPORTED
+static double
+chromaticity_x(CIE_color c)
+{
+   return c.X / (c.X + c.Y + c.Z);
+}
+
+static double
+chromaticity_y(CIE_color c)
+{
+   return c.Y / (c.X + c.Y + c.Z);
+}
+
 static CIE_color
 white_point(PNG_CONST color_encoding *encoding)
 {
@@ -1684,6 +1717,7 @@ white_point(PNG_CONST color_encoding *encoding)
    return white;
 }
 
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
 static void
 normalize_color_encoding(color_encoding *encoding)
 {
@@ -1703,6 +1737,7 @@ normalize_color_encoding(color_encoding *encoding)
       encoding->blue.Z /= whiteY;
    }
 }
+#endif
 
 static size_t
 safecat_color_encoding(char *buffer, size_t bufsize, size_t pos,
@@ -1743,6 +1778,7 @@ safecat_color_encoding(char *buffer, size_t bufsize, size_t pos,
 
    return pos;
 }
+#endif /* PNG_READ_SUPPORTED */
 
 typedef struct png_modifier
 {
@@ -1936,6 +1972,7 @@ modifier_init(png_modifier *pm)
  * to a calculation - not a digitization operation - unless the following API is
  * called directly.
  */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
 static double digitize(PNG_CONST png_modifier *pm, double value,
    int sample_depth, int do_round)
 {
@@ -1960,7 +1997,10 @@ static double digitize(PNG_CONST png_modifier *pm, double value,
    if (do_round) value += .5;
    return floor(value)/digitization_factor;
 }
+#endif
 
+#if (defined PNG_READ_GAMMA_SUPPORTED) ||\
+   (defined PNG_READ_RGB_TO_GRAY_SUPPORTED)
 static double abserr(PNG_CONST png_modifier *pm, int in_depth, int out_depth)
 {
    /* Absolute error permitted in linear values - affected by the bit depth of
@@ -1972,7 +2012,9 @@ static double abserr(PNG_CONST png_modifier *pm, int in_depth, int out_depth)
    else
       return pm->maxabs8;
 }
+#endif
 
+#ifdef PNG_READ_GAMMA_SUPPORTED
 static double calcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth)
 {
    /* Error in the linear composition arithmetic - only relevant when
@@ -2089,6 +2131,7 @@ static int output_quantization_factor(PNG_CONST png_modifier *pm, int in_depth,
    else
       return 1;
 }
+#endif /* PNG_READ_GAMMA_SUPPORTED */
 
 /* One modification structure must be provided for each chunk to be modified (in
  * fact more than one can be provided if multiple separate changes are desired
@@ -2141,6 +2184,7 @@ modification_init(png_modification *pmm)
    modification_reset(pmm);
 }
 
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
 static void
 modifier_current_encoding(PNG_CONST png_modifier *pm, color_encoding *ce)
 {
@@ -2152,6 +2196,7 @@ modifier_current_encoding(PNG_CONST png_modifier *pm, color_encoding *ce)
 
    ce->gamma = pm->current_gamma;
 }
+#endif
 
 static size_t
 safecat_current_encoding(char *buffer, size_t bufsize, size_t pos,
@@ -2777,6 +2822,7 @@ srgb_modification_init(srgb_modification *me, png_modifier *pm, png_byte intent)
    pm->modifications = &me->this;
 }
 
+#ifdef PNG_READ_GAMMA_SUPPORTED
 typedef struct sbit_modification
 {
    png_modification this;
@@ -2843,6 +2889,7 @@ sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit)
    me->this.next = pm->modifications;
    pm->modifications = &me->this;
 }
+#endif /* PNG_READ_GAMMA_SUPPORTED */
 #endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
 /***************************** STANDARD PNG FILES *****************************/
@@ -3121,6 +3168,7 @@ transform_height(png_const_structp pp, png_byte colour_type, png_byte bit_depth)
    }
 }
 
+#ifdef PNG_READ_SUPPORTED
 /* The following can only be defined here, now we have the definitions
  * of the transform image sizes.
  */
@@ -3156,6 +3204,7 @@ standard_rowsize(png_const_structp pp, png_uint_32 id)
    width *= bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id));
    return (width + 7) / 8;
 }
+#endif /* PNG_READ_SUPPORTED */
 
 static void
 transform_row(png_const_structp pp, png_byte buffer[TRANSFORM_ROWMAX],
@@ -3308,6 +3357,11 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
 #ifdef PNG_TEXT_SUPPORTED
+#  if (defined PNG_READ_zTXt_SUPPORTED) && (defined PNG_WRITE_zTXt_SUPPORTED)
+#     define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_zTXt
+#  else
+#     define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_NONE
+#  endif
       {
          static char key[] = "image name"; /* must be writeable */
          size_t pos;
@@ -3317,7 +3371,7 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          /* Use a compressed text string to test the correct interaction of text
           * compression and IDAT compression.
           */
-         text.compression = PNG_TEXT_COMPRESSION_zTXt;
+         text.compression = TEXT_COMPRESSION;
          text.key = key;
          /* Yuck: the text must be writable! */
          pos = safecat(copy, sizeof copy, 0, ps->wname);
@@ -3375,7 +3429,7 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          /* Use a compressed text string to test the correct interaction of text
           * compression and IDAT compression.
           */
-         text.compression = PNG_TEXT_COMPRESSION_zTXt;
+         text.compression = TEXT_COMPRESSION;
          text.key = key;
          text.text = comment;
          text.text_length = (sizeof comment)-1;
@@ -3459,6 +3513,7 @@ interlace_row(png_bytep buffer, png_const_bytep imageRow,
    }
 }
 
+#ifdef PNG_READ_SUPPORTED
 static void
 deinterlace_row(png_bytep buffer, png_const_bytep row,
    unsigned int pixel_size, png_uint_32 w, int pass)
@@ -3479,6 +3534,7 @@ deinterlace_row(png_bytep buffer, png_const_bytep row,
       ++xin;
    }
 }
+#endif /* PNG_READ_SUPPORTED */
 
 /* Build a single row for the 'size' test images; this fills in only the
  * first bit_width bits of the sample row.
@@ -3546,7 +3602,7 @@ make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          /* Use a compressed text string to test the correct interaction of text
           * compression and IDAT compression.
           */
-         text.compression = PNG_TEXT_COMPRESSION_zTXt;
+         text.compression = TEXT_COMPRESSION;
          text.key = key;
          /* Yuck: the text must be writable! */
          pos = safecat(copy, sizeof copy, 0, ps->wname);
@@ -3646,7 +3702,7 @@ make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          /* Use a compressed text string to test the correct interaction of text
           * compression and IDAT compression.
           */
-         text.compression = PNG_TEXT_COMPRESSION_zTXt;
+         text.compression = TEXT_COMPRESSION;
          text.key = key;
          text.text = comment;
          text.text_length = (sizeof comment)-1;
@@ -3722,6 +3778,7 @@ make_size_images(png_store *ps)
    make_size(ps, 6, 3, WRITE_BDHI);
 }
 
+#ifdef PNG_READ_SUPPORTED
 /* Return a row based on image id and 'y' for checking: */
 static void
 standard_row(png_const_structp pp, png_byte std[STANDARD_ROWMAX],
@@ -3733,6 +3790,7 @@ standard_row(png_const_structp pp, png_byte std[STANDARD_ROWMAX],
       size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id),
          DEPTH_FROM_ID(id)), y);
 }
+#endif /* PNG_READ_SUPPORTED */
 
 /* Tests - individual test cases */
 /* Like 'make_standard' but errors are deliberately introduced into the calls
@@ -4017,6 +4075,7 @@ perform_formatting_test(png_store *volatile ps)
 #endif
 }
 
+#ifdef PNG_READ_SUPPORTED
 /* Because we want to use the same code in both the progressive reader and the
  * sequential reader it is necessary to deal with the fact that the progressive
  * reader callbacks only have one parameter (png_get_progressive_ptr()), so this
@@ -4624,11 +4683,11 @@ standard_check_text(png_const_structp pp, png_const_textp tp,
    pos = safecat(msg, sizeof msg, pos, ": ");
    ok = pos;
 
-   if (tp->compression != PNG_TEXT_COMPRESSION_zTXt)
+   if (tp->compression != TEXT_COMPRESSION)
    {
       char buf[64];
 
-      sprintf(buf, "compression [%d->%d], ", PNG_TEXT_COMPRESSION_zTXt,
+      sprintf(buf, "compression [%d->%d], ", TEXT_COMPRESSION,
          tp->compression);
       pos = safecat(msg, sizeof msg, pos, buf);
    }
@@ -4671,21 +4730,21 @@ standard_check_text(png_const_structp pp, png_const_textp tp,
 
    if (tp->itxt_length != 0)
       pos = safecat(msg, sizeof msg, pos, "iTXt length set, ");
-      
+
    if (tp->lang != NULL)
    {
       pos = safecat(msg, sizeof msg, pos, "iTXt language \"");
       pos = safecat(msg, sizeof msg, pos, tp->lang);
       pos = safecat(msg, sizeof msg, pos, "\", ");
    }
-      
+
    if (tp->lang_key != NULL)
    {
       pos = safecat(msg, sizeof msg, pos, "iTXt keyword \"");
       pos = safecat(msg, sizeof msg, pos, tp->lang_key);
       pos = safecat(msg, sizeof msg, pos, "\", ");
    }
-      
+
    if (pos > ok)
    {
       msg[pos-2] = '\0'; /* Remove the ", " at the end */
@@ -5957,6 +6016,7 @@ image_transform_default_ini(PNG_CONST image_transform *this,
    this->next->ini(this->next, that);
 }
 
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
 static int
 image_transform_default_add(image_transform *this,
     PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
@@ -5969,6 +6029,7 @@ image_transform_default_add(image_transform *this,
 
    return 1;
 }
+#endif
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
 /* png_set_palette_to_rgb */
@@ -7647,6 +7708,7 @@ gamma_component_compose(int do_background, double input_sample, double alpha,
 {
    switch (do_background)
    {
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
       case PNG_BACKGROUND_GAMMA_SCREEN:
       case PNG_BACKGROUND_GAMMA_FILE:
       case PNG_BACKGROUND_GAMMA_UNIQUE:
@@ -7664,6 +7726,7 @@ gamma_component_compose(int do_background, double input_sample, double alpha,
                input_sample = background;
          }
          break;
+#endif
 
 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
       case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
@@ -7696,6 +7759,9 @@ gamma_component_compose(int do_background, double input_sample, double alpha,
          /* Standard cases where no compositing is done (so the component
           * value is already correct.)
           */
+         UNUSED(alpha)
+         UNUSED(background)
+         UNUSED(compose)
          break;
    }
 
@@ -8095,11 +8161,13 @@ gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi,
              */
             switch (do_background)
             {
-            case PNG_BACKGROUND_GAMMA_SCREEN:
-            case PNG_BACKGROUND_GAMMA_FILE:
-            case PNG_BACKGROUND_GAMMA_UNIQUE:
-               use_background = (alpha >= 0 && alpha < 1);
-               /*FALL THROUGH*/
+#           ifdef PNG_READ_BACKGROUND_SUPPORTED
+               case PNG_BACKGROUND_GAMMA_SCREEN:
+               case PNG_BACKGROUND_GAMMA_FILE:
+               case PNG_BACKGROUND_GAMMA_UNIQUE:
+                  use_background = (alpha >= 0 && alpha < 1);
+                  /*FALL THROUGH*/
+#           endif
 #           ifdef PNG_READ_ALPHA_MODE_SUPPORTED
                case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
                case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
@@ -9018,7 +9086,9 @@ perform_gamma_test(png_modifier *pm, int summary)
    /* Save certain values for the temporary overrides below. */
    unsigned int calculations_use_input_precision =
       pm->calculations_use_input_precision;
-   double maxout8 = pm->maxout8;
+#  ifdef PNG_READ_BACKGROUND_SUPPORTED
+      double maxout8 = pm->maxout8;
+#  endif
 
    /* First some arbitrary no-transform tests: */
    if (!pm->this.speed && pm->test_gamma_threshold)
@@ -9137,6 +9207,7 @@ perform_gamma_test(png_modifier *pm, int summary)
 #endif
 }
 #endif /* PNG_READ_GAMMA_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED */
 
 /* INTERLACE MACRO VALIDATION */
 /* This is copied verbatim from the specification, it is simply the pass
@@ -9945,7 +10016,9 @@ int main(int argc, char **argv)
       {
          perform_interlace_macro_validation();
          perform_formatting_test(&pm.this);
-         perform_standard_test(&pm);
+#        ifdef PNG_READ_SUPPORTED
+            perform_standard_test(&pm);
+#        endif
          perform_error_test(&pm);
       }
 
@@ -9953,7 +10026,9 @@ int main(int argc, char **argv)
       if (pm.test_size)
       {
          make_size_images(&pm.this);
-         perform_size_test(&pm);
+#        ifdef PNG_READ_SUPPORTED
+            perform_size_test(&pm);
+#        endif
       }
 
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
@@ -10046,7 +10121,20 @@ int main(int argc, char **argv)
             exit(1);
          }
       }
+
+      else
+      {
+         fprintf(stderr, "%s: open failed\n", touch);
+         exit(1);
+      }
    }
 
    return 0;
 }
+#else /* write not supported */
+int main(void)
+{
+   fprintf(stderr, "pngvalid: no write support in libpng, all tests skipped\n");
+   return 0;
+}
+#endif

contrib/libtests/tarith.c

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

contrib/libtests/test-pngunknown.sh

@@ -0,0 +1,38 @@
+#!/bin/sh
+#
+# Run the unknown API tests
+err=0
+image="${srcdir}/pngtest.png"
+#
+# stream 4 is used for the output of the shell, pngtest-log.txt gets all the
+# normal program output.
+exec 4>&1 1>>pngtest-log.txt 2>&1
+
+echo
+echo "============ test-pngunknown.sh =============="
+
+echo "Running test-pngunknown.sh" >&4
+
+for tests in \
+ "discard default=discard"\
+ "save default=save"\
+ "if-safe default=if-safe"\
+ "vpAg vpAg=if-safe"\
+ "sTER sTER=if-safe"\
+ "IDAT default=discard IDAT=save"\
+ "sAPI bKGD=save cHRM=save gAMA=save all=discard iCCP=save sBIT=save sRGB=save"
+do
+   set $tests
+   test="$1"
+   shift
+
+   if ./pngunknown "$@" "$image" 4>&-
+   then
+      echo "  PASS: test-pngunknown $test" >&4
+   else
+      echo "  FAIL: test-pngunknown $test" >&4
+      err=1
+   fi
+done
+
+exit $err

contrib/pngminim/decoder/makefile

@@ -14,7 +14,7 @@ LD=$(CC)
 RM=rm -f
 COPY=cp
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP -I. -O1
+CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP -I. -O1
 
 C=.c
 O=.o

contrib/pngminim/encoder/README

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

contrib/pngminim/encoder/makefile

@@ -14,7 +14,7 @@ LD=$(CC)
 RM=rm -f
 COPY=cp
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZIP -I. -O1
+CFLAGS=-DPNG_USER_CONFIG -DZ_SOLO -DNO_GZIP -I. -O1
 
 C=.c
 O=.o

contrib/pngminim/preader/makefile

@@ -30,7 +30,7 @@ XLIB = -L/usr/X11R6/lib -lX11
 #LIBS = $(XLIB)
 LIBS = $(XLIB) -lm                      #platforms that need libm
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP -I. $(XINC) -O1
+CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP -I. $(XINC) -O1
 
 C=.c
 O=.o

example.c

@@ -48,7 +48,8 @@ int main(int argc, const char **argv)
       png_image image; /* The control structure used by libpng */
 
       /* Initialize the 'png_image' structure. */
-      memset(&image, 0, sizeof image);
+      memset(&image, 0, (sizeof image));
+      image.version = PNG_IMAGE_VERSION;
 
       /* The first argument is the file to read: */
       if (png_image_begin_read_from_file(&image, argv[1]))
@@ -75,16 +76,28 @@ int main(int argc, const char **argv)
           * be supplied or the output buffer would have to be initialized to the
           * actual background of the image.
           *
-          * The final argument to png_image_finish_read is the 'row_stride' -
+          * The fourth argument to png_image_finish_read is the 'row_stride' -
           * this is the number of components allocated for the image in each
           * row.  It has to be at least as big as the value returned by
           * PNG_IMAGE_ROW_STRIDE, but if you just allocate space for the
           * default, minimum, size using PNG_IMAGE_SIZE as above you can pass
           * zero.
+          *
+          * The final argument is a pointer to a buffer for the colormap;
+          * colormaps have exactly the same format as a row of image pixels (so
+          * you choose what format to make the colormap by setting
+          * image.format).  A colormap is only returned if
+          * PNG_FORMAT_FLAG_COLORMAP is also set in image.format, so in this
+          * case NULL is passed as the final argument.  If you do want to force
+          * all images into an index/color-mapped format then you can use:
+          *
+          *    PNG_IMAGE_COLORMAP_SIZE(image)
+          *
+          * to find the maximum size of the colormap in bytes.
           */
          if (buffer != NULL &&
             png_image_finish_read(&image, NULL/*background*/, buffer,
-               0/*row_stride*/))
+               0/*row_stride*/, NULL/*colormap*/))
          {
             /* Now write the image out to the second argument.  In the write
              * call 'convert_to_8bit' allows 16-bit data to be squashed down to
@@ -92,7 +105,7 @@ int main(int argc, const char **argv)
              * to the 8-bit format.
              */
             if (png_image_write_to_file(&image, argv[2], 0/*convert_to_8bit*/,
-               buffer, 0/*row_stride*/))
+               buffer, 0/*row_stride*/, NULL/*colormap*/))
             {
                /* The image has been written successfully. */
                exit(0);
@@ -833,7 +846,7 @@ void write_png(char *file_name /* , ... other image information ... */)
 
    /* Set the palette if there is one.  REQUIRED for indexed-color images */
    palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
-             * png_sizeof(png_color));
+             * (sizeof (png_color)));
    /* ... Set palette colors ... */
    png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
    /* You must not free palette here, because png_set_PLTE only makes a link to
@@ -968,12 +981,16 @@ void write_png(char *file_name /* , ... other image information ... */)
     * use the first method if you aren't handling interlacing yourself.
     */
    png_uint_32 k, height, width;
-   png_byte image[height][width*bytes_per_pixel];
+
+   /* In this example, "image" is a one-dimensional array of bytes */
+   png_byte image[height*width*bytes_per_pixel];
+
    png_bytep row_pointers[height];
 
-   if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+   if (height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
      png_error (png_ptr, "Image is too tall to process in memory");
 
+   /* Set up pointers into your "image" byte array */
    for (k = 0; k < height; k++)
      row_pointers[k] = image + k*width*bytes_per_pixel;
 

libpng-manual.txt

@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.0beta25 - June 16, 2012
+ libpng version 1.6.0beta35 - December 22, 2012
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2011 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.0beta25 - June 16, 2012
+ libpng versions 0.97, January 1998, through 1.6.0beta35 - December 22, 2012
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2011 Glenn Randers-Pehrson
 
@@ -67,7 +67,7 @@ of reducing the amount of time and effort it takes to support the PNG
 file format in application programs.
 
 The PNG specification (second edition), November 2003, is available as
-a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
+a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at
 <http://www.w3.org/TR/2003/REC-PNG-20031110/
 The W3C and ISO documents have identical technical content.
 
@@ -2230,7 +2230,7 @@ sPLT, only the n'th item in the structure is freed, where n is "seq".
 The default behavior is only to free data that was allocated internally
 by libpng.  This can be changed, so that libpng will not free the data,
 or so that it will free data that was allocated by the user with png_malloc()
-or png_zalloc() and passed in via a png_set_*() function, with
+or png_calloc() and passed in via a png_set_*() function, with
 
     png_data_freer(png_ptr, info_ptr, freer, mask)
 
@@ -2251,7 +2251,7 @@ or png_destroy_*() is supposed to free the data.  When the user assumes
 responsibility for libpng-allocated data, the application must use
 png_free() to free it, and when the user transfers responsibility to libpng
 for data that the user has allocated, the user must have used png_malloc()
-or png_zalloc() to allocate it.
+or png_calloc() to allocate it.
 
 If you allocated your row_pointers in a single block, as suggested above in
 the description of the high level read interface, you must not transfer
@@ -2567,6 +2567,20 @@ You can #define PNG_ABORT() to a function that does something
 more useful than abort(), as long as your function does not
 return.
 
+Checking for invalid palette index on write was added at libpng
+1.5.10.  If a pixel contains an invalid (out-of-range) index libpng issues
+a benign error.  This is enabled by default because this condition is an
+error according to the PNG specification, Clause 11.3.2, but the error can
+be ignored in each png_ptr with
+
+   png_set_check_for_invalid_index(png_ptr, 0);
+
+If the error is ignored, or if png_benign_error() treats it as a warning,
+any invalid pixels are written as-is by the encoder, resulting in an
+invalid PNG datastream as output.  In this case the application is
+responsible for ensuring that the pixel indexes are in range when it writes
+a PLTE chunk with fewer entries than the bit depth would allow.
+
 Now you need to set up the output code.  The default for libpng is to
 use the C function fwrite().  If you use this, you will need to pass a
 valid FILE * in the function png_init_io().  Be sure that the file is
@@ -3069,8 +3083,8 @@ tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
 although this isn't a requirement.  Unlike the tIME chunk, the
 "Creation Time" tEXt chunk is not expected to be automatically changed
 by the software.  To facilitate the use of RFC 1123 dates, a function
-png_convert_to_rfc1123_buffer(buffer, png_timep) is provided to convert
-from PNG time to an RFC 1123 format string.  The caller must provide
+png_convert_to_rfc1123_buffer(png_ptr, buffer, png_timep) is provided to
+convert from PNG time to an RFC 1123 format string.  The caller must provide
 a writeable buffer of at least 29 bytes.
 
 Writing unknown chunks
@@ -3433,7 +3447,7 @@ png_destroy_write_struct().
 The default behavior is only to free data that was allocated internally
 by libpng.  This can be changed, so that libpng will not free the data,
 or so that it will free data that was allocated by the user with png_malloc()
-or png_zalloc() and passed in via a png_set_*() function, with
+or png_calloc() and passed in via a png_set_*() function, with
 
     png_data_freer(png_ptr, info_ptr, freer, mask)
 
@@ -3469,7 +3483,7 @@ When the user assumes responsibility for libpng-allocated data, the
 application must use
 png_free() to free it, and when the user transfers responsibility to libpng
 for data that the user has allocated, the user must have used png_malloc()
-or png_zalloc() to allocate it.
+or png_calloc() to allocate it.
 
 If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
 separately, do not transfer responsibility for freeing text_ptr to libpng,
@@ -3524,16 +3538,17 @@ png_image is a structure that describes the in-memory format of an image
 when it is being read or define the in-memory format of an image that you
 need to write.  The "png_image" structure contains the following members:
 
+   png_uint_32  version Set to PNG_IMAGE_VERSION
    png_uint_32  width   Image width in pixels (columns)
    png_uint_32  height  Image height in pixels (rows)
    png_uint_32  format  Image format as defined below
    png_uint_32  flags   A bit mask containing informational flags
    png_controlp opaque  Initialize to NULL, free with png_image_free
-   png_const_bytep colormap A pointer to the application color-map
+   png_uint_32  colormap_entries; Number of entries in the color-map
    png_uint_32  warning_or_error;
    char         message[64];
 
-In the event of an error or warning the following field wrning_or_error
+In the event of an error or warning the following field warning_or_error
 field will be set to a non-zero value and the 'message' field will contain
 a '\0' terminated string with the libpng error or warning message.  If both
 warnings and an error were encountered, only the error is recorded.  If there
@@ -3689,6 +3704,22 @@ First the information about the samples.
    a fixed number determined by the format so can easily be allocated on the
    stack if necessary.
 
+#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
+   (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
+   /* The maximum size of the color-map required by the format expressed in a
+    * count of components.  This can be used to compile-time allocate a
+    * color-map:
+    *
+    * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
+    *
+    * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
+    *
+    * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
+    * information from one of the png_image_begin_read_ APIs and dynamically
+    * allocate the required memory.
+    */
+
+
 Corresponding information about the pixels
 
   PNG_IMAGE_PIXEL_(test,fmt)
@@ -3747,7 +3778,8 @@ READ APIs
       The PNG header is read from the given memory buffer.
 
    int png_image_finish_read(png_imagep image,
-      png_colorp background, void *buffer, png_int_32 row_stride));
+      png_colorp background, void *buffer,
+      png_int_32 row_stride, void *colormap));
 
       Finish reading the image into the supplied buffer and
       clean up the png_image structure.
@@ -3784,6 +3816,7 @@ WRITE APIS
 For write you must initialize a png_image structure to describe the image to
 be written:
 
+   version: must be set to PNG_IMAGE_VERSION
    opaque: must be initialized to NULL
    width: image width in pixels
    height: image height in rows
@@ -3791,15 +3824,17 @@ be written:
    flags: set to 0 unless one of the defined flags applies; set
       PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images
       where the RGB values do not correspond to the colors in sRGB.
+   colormap_entries: set to the number of entries in the color-map (0 to 256)
 
    int png_image_write_to_file, (png_imagep image,
       const char *file, int convert_to_8bit, const void *buffer,
-      png_int_32 row_stride));
+      png_int_32 row_stride, const void *colormap));
 
       Write the image to the named file.
 
    int png_image_write_to_stdio(png_imagep image, FILE *file,
-      int convert_to_8_bit, const void *buffer, png_int_32 row_stride)
+      int convert_to_8_bit, const void *buffer,
+      png_int_32 row_stride, const void *colormap)
 
       Write the image to the given (FILE*).
 
@@ -3833,12 +3868,13 @@ in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively.  To change
 these functions, call the appropriate png_set_*_fn() function.
 
 Memory allocation is done through the functions png_malloc(), png_calloc(),
-and png_free().  These currently just call the standard C functions.
-png_calloc() calls png_malloc() and then clears the newly
-allocated memory to zero.  There is limited support for certain systems
-with segmented memory architectures and the types of pointers declared by
-png.h match this; you will have to use appropriate pointers in your
-application.  Since it is
+and png_free().  The png_malloc() and png_free() functions currently just
+call the standard C functions and png_calloc() calls png_malloc() and then
+clears the newly allocated memory to zero; note that png_calloc(png_ptr, size)
+is not the same as the calloc(number, size) function provided by stdlib.h.
+There is limited support for certain systems with segmented memory
+architectures and the types of pointers declared by png.h match this; you
+will have to use appropriate pointers in your application.  Since it is
 unlikely that the method of handling memory allocation on a platform
 will change between applications, these functions must be modified in
 the library at compile time.  If you prefer to use a different method
@@ -4516,7 +4552,9 @@ png_set_strip_error_numbers() was removed from the library by default.
 
 The png_zalloc() and png_zfree() functions are no longer exported.
 The png_zalloc() function no longer zeroes out the memory that it
-allocates.
+allocates.  Applications that called png_zalloc(png_ptr, number, size)
+can call png_calloc(png_ptr, number*size) instead, and can call
+png_free() instead of png_zfree().
 
 Support for dithering was disabled by default in libpng-1.4.0, because
 it has not been well tested and doesn't actually "dither".
@@ -4538,13 +4576,22 @@ function) incorrectly returned a value of type png_uint_32.
 
 Checking for invalid palette index on read or write was added at libpng
 1.5.10.  When an invalid index is found, libpng issues a benign error.
-This is enabled by default but can be disabled in each png_ptr with
+This is enabled by default because this condition is an error according
+to the PNG specification, Clause 11.3.2, but the error can be ignored in
+each png_ptr with
 
    png_set_check_for_invalid_index(png_ptr, allowed);
 
       allowed  - one of
-                 0: disable
-                 1: enable
+                 0: disable benign error (accept the
+                    invalid data without warning).
+                 1: enable benign error (treat the
+                    invalid data as an error or a
+                    warning).
+
+If the error is ignored, or if png_benign_error() treats it as a warning,
+any invalid pixels are decoded as opaque black by the decoder and written
+as-is by the encoder.
 
 A. Changes that affect users of libpng
 
@@ -4560,9 +4607,12 @@ need access to information in zlib.h will need to add the '#include "zlib.h"'
 directive.  It does not matter whether this is placed prior to or after
 the '"#include png.h"' directive.
 
-We moved the png_strcpy(), png_strncpy(), png_strlen(), png_memcpy(),
-png_memcmp(), png_sprintf, and png_memcpy() macros into a private
-header file (pngpriv.h) that is not accessible by applications.
+The png_sprintf(), png_strcpy(), and png_strncpy() macros are no longer used
+and were removed.
+
+We moved the png_strlen(), png_memcpy(), png_memset(), and png_memcmp()
+macros into a private header file (pngpriv.h) that is not accessible to
+applications.
 
 In png_get_iCCP, the type of "profile" was changed from png_charpp
 to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep.
@@ -4848,10 +4898,27 @@ how to do this, and a case where pngusr.h is still required.
 XII.  Changes to Libpng from version 1.5.x to 1.6.x
 
 A "simplified API" has been added (see documentation in png.h and a simple
-example in contrib/examples/pngtopng.c)
+example in contrib/examples/pngtopng.c).  The new publicly visible API
+includes the following:
+
+   macros:
+     PNG_FORMAT_*
+     PNG_IMAGE_*
+   structures:
+     png_control
+     png_image
+   read functions
+     png_image_begin_read_from_file()
+     png_image_begin_read_from_stdio()
+     png_image_begin_read_from_memory()
+     png_image_finish_read()
+     png_image_free()
+   write functions
+     png_image_write_to_file()
+     png_image_write_to_stdio()
 
 Starting with libpng-1.6.0, you can configure libpng to prefix all exported
-symbols.
+symbols, using the PNG_PREFIX macro.
 
 We no longer include string.h in png.h.  The include statement has been moved
 to pngpriv.h, where it is not accessible by applications.  Applications that
@@ -4863,14 +4930,42 @@ The following API are now DEPRECATED:
    png_info_init_3()
    png_convert_to_rfc1123() which has been replaced
      with png_convert_to_rfc1123_buffer()
+   png_data_freer()
    png_malloc_default()
    png_free_default()
+   png_reset_zstream()
 
 The following has been removed:
    png_get_io_chunk_name(), which has been replaced
      with png_get_io_chunk_type().  The new
      function returns a 32-bit integer instead of
      a string.
+   The png_sizeof(), png_strlen(), png_memcpy(), png_memcmp(), and
+     png_memset() macros are no longer used in the libpng sources and
+     have been removed.  These had already been made invisible to applications
+     (i.e., defined in the private pngpriv.h header file) since libpng-1.5.0.
+
+The signatures of many exported functions were changed, such that
+   png_structp became png_structrp or png_const_structrp
+   png_infop became png_inforp or png_const_inforp
+where "rp" indicates a "restricted pointer".
+
+Error detection in some chunks has improved; in particular the iCCP chunk
+reader now does pretty complete validation of the basic format.  Some bad
+profiles that were previously accepted are now rejected, in particular the
+very old broken Microsoft/HP sRGB profile.
+
+The library now issues a warning if both background processing and RGB to
+gray are used when gamma correction happens. As with previous versions of
+the library the results are numerically very incorrect in this case.
+
+There are some minor arithmetic changes in some transforms such as
+png_set_background(), that might be detected by certain regression tests.
+
+Unknown chunk handling has been improved internally, without any API change.
+This adds more correct option control of the unknown handling, corrects
+a pre-existing bug where the per-chunk 'keep' setting is ignored, and makes
+it possible to skip IDAT chunks in the sequential reader.
 
 XIII.  Detecting libpng
 
@@ -4988,10 +5083,21 @@ pngtest) appear in
 pngpriv.h
 above the comment that says
 
-  /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+  /* Maintainer: Put new private prototypes here ^ */
+
+We put a space after the "sizeof" operator and we omit the
+optional parentheses around its argument when the argument
+is an expression, not a type name, and we always enclose the
+sizeof operator, with its argument, in parentheses:
+
+  (sizeof (png_uint_32))
+  (sizeof array)
+
+Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as
+though it were a function.
 
 To avoid polluting the global namespace, the names of all exported
-functions and variables begin with  "png_", and all publicly visible C
+functions and variables begin with "png_", and all publicly visible C
 preprocessor macros begin with "PNG".  We request that applications that
 use libpng *not* begin any of their own symbols with either of these strings.
 
@@ -5005,12 +5111,15 @@ left parenthesis that follows it:
     for (i = 2; i > 0; --i)
        y[i] = a(x) + (int)b;
 
-We prefer #ifdef and #ifndef to #if defined() and if !defined()
+We prefer #ifdef and #ifndef to #if defined() and #if !defined()
 when there is only one macro being tested.
 
 We prefer to express integers that are used as bit masks in hex format,
 with an even number of lower-case hex digits (e.g., 0x00, 0xff, 0x0100).
 
+We prefer to use underscores in variable names rather than camelCase, except
+for a few type names that we inherit from zlib.h.
+
 We do not use the TAB character for indentation in the C sources.
 
 Lines do not exceed 80 characters.
@@ -5019,13 +5128,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 XVI. Y2K Compliance in libpng
 
-June 16, 2012
+December 22, 2012
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.0beta25 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.0beta35 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has two year fields.  One is a 2-byte unsigned integer

libpngpf.3

@@ -1,21 +1,11 @@
-.TH LIBPNGPF 3 "June 16, 2012"
+.TH LIBPNGPF 3 "December 22, 2012"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.0beta25
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.0beta35
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
 
-\fI\fB
-
-\fBAs of libpng version \fP\fI1.5.1\fP\fB, this section is no longer \fP\fImaintained\fP\fB, now \fIthat
-
-\fBthe private function prototypes are hidden in pngpriv.h and not \fIaccessible
-
-\fBto applications. Look in pngpriv.h for the prototypes and a short \fIdescription
-
-\fBof each \fIfunction.
-
-\fI\fB
+\fBAs of libpng version \fP\fI1.5.1\fP\fB, this section is no longer \fP\fImaintained\fP\fB, now that the private function prototypes are hidden in pngpriv.h and not accessible to applications. Look in pngpriv.h for the prototypes and a short description of each \fIfunction.
 
 .SH DESCRIPTION
 The functions previously listed here are used privately by libpng and are not

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "June 16, 2012"
+.TH PNG 5 "December 22, 2012"
 .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 1.6.0beta25 - June 16, 2012
+ * libpng version 1.6.0beta35 - December 22, 2012
  * Copyright (c) 1998-2012 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 1.6.0beta25 - June 16, 2012: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.0beta35 - December 22, 2012: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -166,7 +166,7 @@
  *    1.5.7beta01-05          15    10507  15.so.15.7[.0]
  *    1.5.7rc01-03            15    10507  15.so.15.7[.0]
  *    1.5.7                   15    10507  15.so.15.7[.0]
- *    1.6.0beta01-25          16    10600  16.so.16.0[.0]
+ *    1.6.0beta01-35          16    10600  16.so.16.0[.0]
  *
  *   Henceforth the source version will match the shared-library major
  *   and minor numbers; the shared-library major version number will be
@@ -198,7 +198,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.0beta25, June 16, 2012, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.6.0beta35, December 22, 2012, are
  * Copyright (c) 2004, 2006-2012 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:
@@ -310,13 +310,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    June 16, 2012
+ *    December 22, 2012
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.6.0beta25 are Y2K compliant.  It is my belief that
+ *    upward through 1.6.0beta35 are Y2K compliant.  It is my belief that
  *    earlier versions were also Y2K compliant.
  *
  *    Libpng only has two year fields.  One is a 2-byte unsigned integer
@@ -376,9 +376,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.0beta25"
+#define PNG_LIBPNG_VER_STRING "1.6.0beta35"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.0beta25 - June 16, 2012\n"
+     " libpng version 1.6.0beta35 - December 22, 2012\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -392,7 +392,7 @@
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
 
-#define PNG_LIBPNG_VER_BUILD  25
+#define PNG_LIBPNG_VER_BUILD  35
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
@@ -522,7 +522,7 @@ 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_6_0beta25;
+typedef char* png_libpng_version_1_6_0beta35;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -704,20 +704,26 @@ typedef png_time * png_timep;
 typedef const png_time * png_const_timep;
 typedef png_time * * png_timepp;
 
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
-    defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 /* png_unknown_chunk is a structure to hold queued chunks for which there is
  * no specific support.  The idea is that we can use this to queue
  * up private chunks for output even though the library doesn't actually
  * know about their semantics.
+ *
+ * The data in the structure is set by libpng on read and used on write.
  */
 typedef struct png_unknown_chunk_t
 {
-    png_byte name[5];
-    png_byte *data;
+    png_byte name[5]; /* Textual chunk name with '\0' terminator */
+    png_byte *data;   /* Data, should not be modified on read! */
     png_size_t size;
 
-    /* libpng-using applications should NOT directly modify this byte. */
+    /* On write 'location' must be set using the flag values listed below.
+     * Notice that on read it is set by libpng however the values stored have
+     * more bits set than are listed below.  Always treat the value as a
+     * bitmask.  On write set only one bit - setting multiple bits may cause the
+     * chunk to be written in multiple places.
+     */
     png_byte location; /* mode of operation at read time */
 }
 png_unknown_chunk;
@@ -727,8 +733,7 @@ typedef const png_unknown_chunk * png_const_unknown_chunkp;
 typedef png_unknown_chunk * * png_unknown_chunkpp;
 #endif
 
-/* Values for the unknown chunk location byte */
-
+/* Flag values for the unknown chunk location byte. */
 #define PNG_HAVE_IHDR  0x01
 #define PNG_HAVE_PLTE  0x02
 #define PNG_AFTER_IDAT 0x08
@@ -896,7 +901,8 @@ typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
     png_unknown_chunkp));
 #endif
 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
-typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp));
+/* not used anywhere */
+/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
@@ -1034,7 +1040,7 @@ PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
     png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
 #  define png_jmpbuf(png_ptr) \
-      (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
+      (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
 #else
 #  define png_jmpbuf(png_ptr) \
       (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
@@ -1238,7 +1244,7 @@ PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
     int mode, png_fixed_point output_gamma))
 #endif
 
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+#if defined(PNG_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
@@ -1544,7 +1550,8 @@ PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
 #endif
 
 /* Write a row of image data */
-PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, png_const_bytep row));
+PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
+    png_const_bytep row));
 
 /* Write a few rows of image data: (*row) is not written; however, the type
  * is declared as writeable to maintain compatibility with previous versions
@@ -1558,7 +1565,8 @@ PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
 
 /* Write the end of the PNG file. */
-PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, png_inforp info_ptr));
+PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
+    png_inforp info_ptr));
 
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 /* Read the end of the PNG file. */
@@ -1826,9 +1834,31 @@ PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
 #endif
 
-#ifdef PNG_USER_CHUNKS_SUPPORTED
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+/* This callback is called only for *unknown* chunks, if
+ * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
+ * chunks to be treated as unknown, however in this case the callback must do
+ * any processing required by the chunk (e.g. by calling the appropriate
+ * png_set_ APIs.)
+ *
+ * There is no write support - on write, by default, all the chunks in the
+ * 'unknown' list are written in the specified position.
+ *
+ * The integer return from the callback function is interpreted thus:
+ *
+ * negative: An error occured, png_chunk_error will be called.
+ *     zero: The chunk was not handled, the chunk will be discarded unless
+ *           png_set_keep_unknown_chunks has been used to set a 'keep' behavior
+ *           for this particular chunk, in which case that will be used.  A
+ *           critical chunk will cause an error at this point unless it is to be
+ *           saved.
+ * positive: The chunk was handled, libpng will ignore/discard it.
+ */
 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
     png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
 #endif
 
@@ -1841,11 +1871,12 @@ PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
     png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
 
 /* Returns the user pointer associated with the push read functions */
-PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structrp png_ptr));
+PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
+    (png_const_structrp png_ptr));
 
 /* Function to be called when data becomes available */
-PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, png_inforp info_ptr,
-    png_bytep buffer, png_size_t buffer_size));
+PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
+    png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size));
 
 /* A function which may be called *only* within png_process_data to stop the
  * processing of any more data.  The function returns the number of bytes
@@ -1913,8 +1944,10 @@ PNG_EXPORTA(99, void, png_data_freer, (png_const_structrp png_ptr,
 #define PNG_FREE_ROWS 0x0040
 #define PNG_FREE_PCAL 0x0080
 #define PNG_FREE_SCAL 0x0100
-#define PNG_FREE_UNKN 0x0200
-#define PNG_FREE_LIST 0x0400
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#  define PNG_FREE_UNKN 0x0200
+#endif
+/*      PNG_FREE_LIST 0x0400    removed in 1.6.0 because it is ignored */
 #define PNG_FREE_PLTE 0x1000
 #define PNG_FREE_TRNS 0x2000
 #define PNG_FREE_TEXT 0x4000
@@ -1958,9 +1991,11 @@ PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
     png_const_charp warning_message));
 
-/* Same, chunk name is prepended to message. */
+#ifdef PNG_READ_SUPPORTED
+/* Same, chunk name is prepended to message (only during read) */
 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
     png_const_charp warning_message));
+#endif
 
 PNG_EXPORT(109, void, png_set_benign_errors,
     (png_structrp png_ptr, int allowed));
@@ -2067,9 +2102,11 @@ PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
 
 #endif /* PNG_EASY_ACCESS_SUPPORTED */
 
+#ifdef PNG_READ_SUPPORTED
 /* Returns pointer to signature string read from PNG header */
 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
     png_const_inforp info_ptr));
+#endif
 
 #ifdef PNG_bKGD_SUPPORTED
 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
@@ -2317,40 +2354,123 @@ PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
     png_const_charp swidth, png_const_charp sheight));
 #endif /* PNG_sCAL_SUPPORTED */
 
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-/* 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.  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
- * If num_chunks is 0, then the "keep" parameter specifies the default
- * manner for handling unknown chunks.  If num_chunks is positive, then
- * the "keep" parameter specifies the manner for handling only those chunks
- * appearing in the chunk_list array.  If it is negative, then the "keep"
- * parameter specifies the manner for handling all unknown chunks plus
- * all chunks recognized by libpng except for the IHDR, PLTE, tRNS, IDAT,
- * and IEND chunks.
-*/
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+/* Provide the default handling for all unknown chunks or, optionally, for
+ * specific unknown chunks.
+ *
+ * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
+ * ignored and the default was used, the per-chunk setting only had an effect on
+ * write.  If you wish to have chunk-specific handling on read in code that must
+ * work on earlier versions you must use a user chunk callback to specify the
+ * desired handling (keep or discard.)
+ *
+ * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below.  The
+ * parameter is interpreted as follows:
+ *
+ * READ:
+ *    PNG_HANDLE_CHUNK_AS_DEFAULT:
+ *       Known chunks: do normal libpng processing, do not keep the chunk (but
+ *          set the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+ *       Unknown chunks: for a specific chunk use the global default, when used
+ *          as the default discard the chunk data.
+ *    PNG_HANDLE_CHUNK_NEVER:
+ *       Discard the chunk data.
+ *    PNG_HANDLE_CHUNK_IF_SAFE:
+ *       Keep the chunk data if the chunk is not critical else raise a chunk
+ *       error.
+ *    PNG_HANDLE_CHUNK_ALWAYS:
+ *       Keep the chunk data.
+ *
+ * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
+ * below.  Notice that specifying "AS_DEFAULT" as a global default is equivalent
+ * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
+ * it simply resets the behavior to the libpng default.
+ *
+ * The per-chunk handling is always used when there is a png_user_chunk_ptr
+ * callback and the callback returns 0; the chunk is then always stored *unless*
+ * it is critical and the per-chunk setting is other than ALWAYS.  Notice that
+ * the global default is *not* used in this case.  (In effect the per-chunk
+ * value is incremented to at least IF_SAFE.)
+ *
+ * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
+ *    If this is *not* set known chunks will always be handled by libpng and
+ *    will never be stored in the unknown chunk list.  Known chunks listed to
+ *    png_set_keep_unknown_chunks will have no effect.  If it is set then known
+ *    chunks listed with a keep other than AS_DEFAULT will *never* be processed
+ *    by libpng, in addition critical chunks must either be processed by the
+ *    callback or saved.
+ *
+ *    The IHDR and IEND chunks 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!
+ *
+ * WRITE:
+ *    When writing chunks the options only apply to the chunks specified by
+ *    png_set_unknown_chunks (below), libpng will *always* write known chunks
+ *    required by png_set_ calls and will always write the core critical chunks
+ *    (as required for PLTE).
+ *
+ *    Each chunk in the png_set_unknown_chunks list is looked up in the
+ *    png_set_keep_unknown_chunks list to find the keep setting, this is then
+ *    interpreted as follows:
+ *
+ *    PNG_HANDLE_CHUNK_AS_DEFAULT:
+ *       Write safe-to-copy chunks and write other chunks if the global
+ *       default is set to _ALWAYS, otherwise don't write this chunk.
+ *    PNG_HANDLE_CHUNK_NEVER:
+ *       Do not write the chunk.
+ *    PNG_HANDLE_CHUNK_IF_SAFE:
+ *       Write the chunk if it is safe-to-copy, otherwise do not write it.
+ *    PNG_HANDLE_CHUNK_ALWAYS:
+ *       Write the chunk.
+ *
+ * Note that the default behavior is effectively the opposite of the read case -
+ * in read unknown chunks are not stored by default, in write they are written
+ * by default.  Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
+ * - on write the safe-to-copy bit is checked, on read the critical bit is
+ * checked and on read if the chunk is critical an error will be raised.
+ *
+ * num_chunks:
+ * ===========
+ *    If num_chunks is positive, then the "keep" parameter specifies the manner
+ *    for handling only those chunks appearing in the chunk_list array,
+ *    otherwise the chunk list array is ignored.
+ *
+ *    If num_chunks is 0 the "keep" parameter specifies the default behavior for
+ *    unknown chunks, as described above.
+ *
+ *    If num_chunks is negative, then the "keep" parameter specifies the manner
+ *    for handling all unknown chunks plus all chunks recognized by libpng
+ *    except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
+ *    be processed by libpng.
+ */
 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp 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.
+/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk 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_structrp png_ptr,
+PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
     png_const_bytep chunk_name));
 #endif
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
     png_inforp info_ptr, png_const_unknown_chunkp unknowns,
     int num_unknowns));
+   /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
+    * unknowns to the location currently stored in the png_struct.  This is
+    * invariably the wrong value on write.  To fix this call the following API
+    * for each chunk in the list with the correct location.  If you know your
+    * code won't be compiled on earlier versions you can rely on
+    * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
+    * the correct thing.
+    */
+
 PNG_EXPORT(175, void, png_set_unknown_chunk_location,
     (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
+
 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
     png_const_inforp info_ptr, png_unknown_chunkpp entries));
 #endif
@@ -2389,6 +2509,7 @@ PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
 #define PNG_HANDLE_CHUNK_NEVER        1
 #define PNG_HANDLE_CHUNK_IF_SAFE      2
 #define PNG_HANDLE_CHUNK_ALWAYS       3
+#define PNG_HANDLE_CHUNK_LAST         4
 
 /* Strip the prepended error numbers ("#nnn ") from error and warning
  * messages before passing them to the error or warning handler.
@@ -2514,10 +2635,10 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
  * necessary to find the row in the output image given a row in an interlaced
  * image, so two more macros:
  */
-#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
-   (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
-#define PNG_COL_FROM_PASS_COL(xIn, pass) \
-   (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
+#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
+   (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
+#define PNG_COL_FROM_PASS_COL(x_in, pass) \
+   (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
 
 /* Two macros which return a boolean (0 or 1) saying whether the given row
  * or column is in a particular pass.  These use a common utility macro that
@@ -2657,7 +2778,7 @@ PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
  * formats do not accomodate your needs then you can, and should, use the more
  * sophisticated APIs above - these support a wide variety of in-memory formats
  * and a wide variety of sophisticated transformations to those formats as well
- * as a wide variety of APIs to manipulate ancilliary information.
+ * as a wide variety of APIs to manipulate ancillary information.
  *
  * To read a PNG file using the simplified API:
  *

pngconf.h

@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.0beta25 - June 16, 2012
+ * libpng version 1.6.0beta35 - December 22, 2012
  *
  * Copyright (c) 1998-2012 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -198,18 +198,16 @@
  * ==========================
  * This code is used at build time to find PNG_IMPEXP, the API settings
  * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
- * import processing is possible.  On Windows/x86 systems it also sets
+ * import processing is possible.  On Windows systems it also sets
  * compiler-specific macros to the values required to change the calling
  * conventions of the various functions.
  */
-#if ( defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
-      defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) ) &&\
-    ( defined(_X86_) || defined(_X64_) || defined(_M_IX86) ||\
-      defined(_M_X64) || defined(_M_IA64) )
-  /* Windows system (DOS doesn't support DLLs) running on x86/x64.  Includes
-   * builds under Cygwin or MinGW.  Also includes Watcom builds but these need
-   * special treatment because they are not compatible with GCC or Visual C
-   * because of different calling conventions.
+#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
+    defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
+  /* Windows system (DOS doesn't support DLLs).  Includes builds under Cygwin or
+   * MinGW on any architecture currently supported by Windows.  Also includes
+   * Watcom builds but these need special treatment because they are not
+   * compatible with GCC or Visual C because of different calling conventions.
    */
 #  if PNG_API_RULE == 2
     /* If this line results in an error, either because __watcall is not
@@ -223,6 +221,9 @@
 #  if defined(__GNUC__) || (defined (_MSC_VER) && (_MSC_VER >= 800))
 #    define PNGCAPI __cdecl
 #    if PNG_API_RULE == 1
+       /* If this line results in an error __stdcall is not understood and
+        * PNG_API_RULE should not have been set to '1'.
+        */
 #      define PNGAPI __stdcall
 #    endif
 #  else
@@ -260,7 +261,7 @@
 #    endif
 #  endif /* compiler */
 
-#else /* !Windows/x86 */
+#else /* !Windows */
 #  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
 #    define PNGAPI _System
 #  else /* !Windows/x86 && !OS/2 */
@@ -366,24 +367,28 @@
 #    ifndef PNG_NORETURN
 #      define PNG_NORETURN   __attribute__((__noreturn__))
 #    endif
-#    ifndef PNG_ALLOCATED
-#      define PNG_ALLOCATED  __attribute__((__malloc__))
-#    endif
-#    ifndef PNG_DEPRECATED
-#      define PNG_DEPRECATED __attribute__((__deprecated__))
-#    endif
-#    ifndef PNG_PRIVATE
-#      if 0 /* Doesn't work so we use deprecated instead*/
-#        define PNG_PRIVATE \
-          __attribute__((warning("This function is not exported by libpng.")))
-#      else
-#        define PNG_PRIVATE \
-          __attribute__((__deprecated__))
+#    if __GNUC__ >= 3
+#      ifndef PNG_ALLOCATED
+#        define PNG_ALLOCATED  __attribute__((__malloc__))
 #      endif
-#    endif
-#    ifndef PNG_RESTRICT
-#      define PNG_RESTRICT __restrict
-#    endif
+#      ifndef PNG_DEPRECATED
+#        define PNG_DEPRECATED __attribute__((__deprecated__))
+#      endif
+#      ifndef PNG_PRIVATE
+#        if 0 /* Doesn't work so we use deprecated instead*/
+#          define PNG_PRIVATE \
+            __attribute__((warning("This function is not exported by libpng.")))
+#        else
+#          define PNG_PRIVATE \
+            __attribute__((__deprecated__))
+#        endif
+#      endif
+#      if ((__GNUC__ != 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
+#        ifndef PNG_RESTRICT
+#          define PNG_RESTRICT __restrict
+#        endif
+#      endif /*  __GNUC__ == 3.0 */
+#    endif /*  __GNUC__ >= 3 */
 
 #  elif defined(_MSC_VER)  && (_MSC_VER >= 1300)
 #    ifndef PNG_USE_RESULT
@@ -431,6 +436,9 @@
 #ifndef PNG_PRIVATE
 #  define PNG_PRIVATE     /* This is a private libpng function */
 #endif
+#ifndef PNG_RESTRICT
+#  define PNG_RESTRICT    /* The C99 "restrict" feature */
+#endif
 #ifndef PNG_FP_EXPORT     /* A floating point API. */
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 #     define PNG_FP_EXPORT(ordinal, type, name, args)\
@@ -542,12 +550,6 @@ typedef ptrdiff_t png_ptrdiff_t;
    typedef png_size_t png_alloc_size_t;
 #endif
 
-/* This macro makes the sizeof operator look and behave like a function, except
- * that it can take a type without the enclosing () as an argument so long as
- * the type contains no "," characters.
- */
-#define png_sizeof(x) (sizeof (x))
-
 /* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
  * implementations of Intel CPU specific support of user-mode segmented address
  * spaces, where 16-bit pointers address more than 65536 bytes of memory using

pngerror.c

@@ -80,7 +80,8 @@ png_error,(png_const_structrp png_ptr, png_const_charp error_message),
    }
 #endif
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), error_message);
+      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
+          error_message);
 
    /* If the custom handler doesn't exist, or if it returns,
       use the default handler, which will not return. */
@@ -162,7 +163,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
          case PNG_NUMBER_FORMAT_02u:
             /* Expects at least 2 digits. */
             mincount = 2;
-            /* fall through */
+            /* FALL THROUGH */
 
          case PNG_NUMBER_FORMAT_u:
             *--end = digits[number % 10];
@@ -172,7 +173,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
          case PNG_NUMBER_FORMAT_02x:
             /* This format expects at least two digits */
             mincount = 2;
-            /* fall through */
+            /* FALL THROUGH */
 
          case PNG_NUMBER_FORMAT_x:
             *--end = digits[number & 0xf];
@@ -414,7 +415,7 @@ static PNG_CONST char png_digit[16] = {
    'A', 'B', 'C', 'D', 'E', 'F'
 };
 
-#define PNG_MAX_ERROR_TEXT 64
+#define PNG_MAX_ERROR_TEXT 196 /* Currently limited be profile_error in png.c */
 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
 static void /* PRIVATE */
 png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
@@ -497,7 +498,8 @@ png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 #ifdef PNG_READ_SUPPORTED
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 void PNGAPI
-png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
+png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
+    error_message)
 {
    if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
       png_chunk_warning(png_ptr, error_message);
@@ -508,6 +510,41 @@ png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp error_message
 #endif
 #endif /* PNG_READ_SUPPORTED */
 
+void /* PRIVATE */
+png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
+{
+   /* This is always supported, but for just read or just write it
+    * unconditionally does the right thing.
+    */
+#  if (defined PNG_READ_SUPPORTED) && (defined PNG_WRITE_SUPPORTED)
+      if (png_ptr->mode & PNG_IS_READ_STRUCT)
+#  endif
+
+#  ifdef PNG_READ_SUPPORTED
+      {
+         if (error < PNG_CHUNK_ERROR)
+            png_chunk_warning(png_ptr, message);
+
+         else
+            png_chunk_benign_error(png_ptr, message);
+      }
+#  endif
+
+#  if (defined PNG_READ_SUPPORTED) && (defined PNG_WRITE_SUPPORTED)
+      else if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
+#  endif
+
+#  ifdef PNG_WRITE_SUPPORTED
+      {
+         if (error < PNG_CHUNK_WRITE_ERROR)
+            png_app_warning(png_ptr, message);
+
+         else
+            png_app_error(png_ptr, message);
+      }
+#  endif
+}
+
 #ifdef PNG_ERROR_TEXT_SUPPORTED
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 PNG_FUNCTION(void,
@@ -517,7 +554,7 @@ png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
 #  define fixed_message_ln ((sizeof fixed_message)-1)
    int  iin;
    char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
-   png_memcpy(msg, fixed_message, fixed_message_ln);
+   memcpy(msg, fixed_message, fixed_message_ln);
    iin = 0;
    if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
    {
@@ -555,7 +592,7 @@ png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
    {
       png_ptr->jmp_buf_size = 0; /* not allocated */
 
-      if (jmp_buf_size <= sizeof png_ptr->jmp_buf_local)
+      if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
          png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
 
       else
@@ -576,7 +613,7 @@ png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
 
       if (size == 0)
       {
-         size = sizeof png_ptr->jmp_buf_local;
+         size = (sizeof png_ptr->jmp_buf_local);
          if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
          {
             /* This is an internal error in libpng: somehow we have been left
@@ -825,7 +862,7 @@ png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
     */
    if (image != NULL)
    {
-      png_safecat(image->message, sizeof image->message, 0, error_message);
+      png_safecat(image->message, (sizeof image->message), 0, error_message);
       image->warning_or_error |= PNG_IMAGE_ERROR;
 
       /* Retrieve the jmp_buf from within the png_control, making this work for
@@ -837,9 +874,10 @@ png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
 
       /* Missing longjmp buffer, the following is to help debugging: */
       {
-         size_t pos = png_safecat(image->message, sizeof image->message, 0,
+         size_t pos = png_safecat(image->message, (sizeof image->message), 0,
             "bad longjmp: ");
-         png_safecat(image->message, sizeof image->message, pos, error_message);
+         png_safecat(image->message, (sizeof image->message), pos,
+             error_message);
       }
    }
 
@@ -857,16 +895,16 @@ png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
    /* A warning is only logged if there is no prior warning or error. */
    if (image->warning_or_error == 0)
    {
-      png_safecat(image->message, sizeof image->message, 0, warning_message);
+      png_safecat(image->message, (sizeof image->message), 0, warning_message);
       image->warning_or_error |= PNG_IMAGE_WARNING;
    }
 }
 #endif
 
 int /* PRIVATE */
-png_safe_execute(png_imagep imageIn, int (*function)(png_voidp), png_voidp arg)
+png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
 {
-   volatile png_imagep image = imageIn;
+   volatile png_imagep image = image_in;
    volatile int result;
    volatile png_voidp saved_error_buf;
    jmp_buf safe_jmpbuf;

pngget.c

@@ -112,7 +112,8 @@ png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
 }
 
 png_uint_32 PNGAPI
-png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
+png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -129,7 +130,8 @@ png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr
 }
 
 png_uint_32 PNGAPI
-png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
+png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+    info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -164,7 +166,8 @@ png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 float PNGAPI
-png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp info_ptr)
+png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
 {
 #ifdef PNG_READ_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -175,6 +178,9 @@ png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp info_ptr
          return ((float)((float)info_ptr->y_pixels_per_unit
              /(float)info_ptr->x_pixels_per_unit));
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return ((float)0.0);
@@ -203,6 +209,9 @@ png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
           (png_int_32)info_ptr->x_pixels_per_unit))
          return res;
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return 0;
@@ -422,6 +431,7 @@ png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #endif  /* PNG_EASY_ACCESS_SUPPORTED */
 
+
 png_byte PNGAPI
 png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
@@ -431,6 +441,7 @@ png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
    return (0);
 }
 
+#ifdef PNG_READ_SUPPORTED
 png_const_bytep PNGAPI
 png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
@@ -439,6 +450,7 @@ png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
 
    return (NULL);
 }
+#endif
 
 #ifdef PNG_bKGD_SUPPORTED
 png_uint_32 PNGAPI
@@ -522,31 +534,31 @@ png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
       png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
 
       if (red_X != NULL)
-         *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.redX,
+         *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
             "cHRM red X");
       if (red_Y != NULL)
-         *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.redY,
+         *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y,
             "cHRM red Y");
       if (red_Z != NULL)
-         *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.redZ,
+         *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
             "cHRM red Z");
       if (green_X != NULL)
          *green_X = png_float(png_ptr,
-            info_ptr->colorspace.end_points_XYZ.greenX, "cHRM green X");
+            info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X");
       if (green_Y != NULL)
          *green_Y = png_float(png_ptr,
-            info_ptr->colorspace.end_points_XYZ.greenY, "cHRM green Y");
+            info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y");
       if (green_Z != NULL)
          *green_Z = png_float(png_ptr,
-            info_ptr->colorspace.end_points_XYZ.greenZ, "cHRM green Z");
+            info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z");
       if (blue_X != NULL)
-         *blue_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.blueX,
+         *blue_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.blue_X,
             "cHRM blue X");
       if (blue_Y != NULL)
-         *blue_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.blueY,
+         *blue_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.blue_Y,
             "cHRM blue Y");
       if (blue_Z != NULL)
-         *blue_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.blueZ,
+         *blue_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.blue_Z,
             "cHRM blue Z");
       return (PNG_INFO_cHRM);
    }
@@ -570,23 +582,23 @@ png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
       png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
 
       if (int_red_X != NULL)
-         *int_red_X = info_ptr->colorspace.end_points_XYZ.redX;
+         *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X;
       if (int_red_Y != NULL)
-         *int_red_Y = info_ptr->colorspace.end_points_XYZ.redY;
+         *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y;
       if (int_red_Z != NULL)
-         *int_red_Z = info_ptr->colorspace.end_points_XYZ.redZ;
+         *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z;
       if (int_green_X != NULL)
-         *int_green_X = info_ptr->colorspace.end_points_XYZ.greenX;
+         *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X;
       if (int_green_Y != NULL)
-         *int_green_Y = info_ptr->colorspace.end_points_XYZ.greenY;
+         *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y;
       if (int_green_Z != NULL)
-         *int_green_Z = info_ptr->colorspace.end_points_XYZ.greenZ;
+         *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z;
       if (int_blue_X != NULL)
-         *int_blue_X = info_ptr->colorspace.end_points_XYZ.blueX;
+         *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X;
       if (int_blue_Y != NULL)
-         *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blueY;
+         *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y;
       if (int_blue_Z != NULL)
-         *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blueZ;
+         *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z;
       return (PNG_INFO_cHRM);
    }
 
@@ -1050,7 +1062,7 @@ png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
 }
 #endif
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 int PNGAPI
 png_get_unknown_chunks(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_unknown_chunkpp unknowns)

pnginfo.h

@@ -55,7 +55,7 @@
 
 struct png_info_def
 {
-   /* the following are necessary for every PNG file */
+   /* The following are necessary for every PNG file */
    png_uint_32 width;  /* width of image in pixels (from IHDR) */
    png_uint_32 height; /* height of image in pixels (from IHDR) */
    png_uint_32 valid;  /* valid chunk data (see PNG_INFO_ below) */
@@ -70,11 +70,15 @@ struct png_info_def
    png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
    png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
 
-#ifdef PNG_READ_SUPPORTED
-   /* The following is informational only on read, and not used on writes. */
+   /* The following are set by png_set_IHDR, called from the application on
+    * write, but the are never actually used by the write code.
+    */
    png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
    png_byte pixel_depth;    /* number of bits per pixel */
    png_byte spare_byte;     /* to align the data, and for future use */
+
+#ifdef PNG_READ_SUPPORTED
+   /* This is never set during write */
    png_byte signature[8];   /* magic bytes read by libpng from start of file */
 #endif
 
@@ -216,11 +220,10 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
 /* New members added in libpng-1.0.6 */
    png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
 
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
- defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
    /* Storage for unknown chunks that the library doesn't recognize. */
    png_unknown_chunkp unknown_chunks;
-   int unknown_chunks_num;
+   unsigned int unknown_chunks_num;
 #endif
 
 #ifdef PNG_sPLT_SUPPORTED

pngmem.c

@@ -30,7 +30,7 @@ png_destroy_png_struct(png_structrp png_ptr)
        * png_get_mem_ptr, so fake a temporary png_struct to support this.
        */
       png_struct dummy_struct = *png_ptr;
-      memset(png_ptr, 0, sizeof *png_ptr);
+      memset(png_ptr, 0, (sizeof *png_ptr));
       png_free(&dummy_struct, png_ptr);
 
 #     ifdef PNG_SETJMP_SUPPORTED
@@ -54,7 +54,7 @@ png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
    ret = png_malloc(png_ptr, size);
 
    if (ret != NULL)
-      png_memset(ret, 0, size);
+      memset(ret, 0, size);
 
    return ret;
 }

pngpread.c

@@ -185,6 +185,9 @@ void /* PRIVATE */
 png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 {
    png_uint_32 chunk_name;
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   int keep; /* unknown handling method */
+#endif
 
    /* First we make sure we have enough data for the 4 byte chunk name
     * and the 4 byte chunk length before proceeding with decoding the
@@ -216,14 +219,28 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 
    if (chunk_name == png_IDAT)
    {
-      /* This is here above the if/else case statement below because if the
-       * unknown handling marks 'IDAT' as unknown then the IDAT handling case is
-       * completely skipped.
-       *
-       * TODO: there must be a better way of doing this.
-       */
       if (png_ptr->mode & PNG_AFTER_IDAT)
          png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+      /* If we reach an IDAT chunk, this means we have read all of the
+       * header chunks, and we can start reading the image (or if this
+       * is called after the image has been read - we have an error).
+       */
+      if (!(png_ptr->mode & PNG_HAVE_IHDR))
+         png_error(png_ptr, "Missing IHDR before IDAT");
+
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+          !(png_ptr->mode & PNG_HAVE_PLTE))
+         png_error(png_ptr, "Missing PLTE before IDAT");
+
+      png_ptr->mode |= PNG_HAVE_IDAT;
+
+      if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+         if (png_ptr->push_length == 0)
+            return;
+
+      if (png_ptr->mode & PNG_AFTER_IDAT)
+         png_benign_error(png_ptr, "Too many IDATs found");
    }
 
    if (chunk_name == png_IHDR)
@@ -255,7 +272,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
    }
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   else if (png_chunk_unknown_handling(png_ptr, chunk_name))
+   else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -263,23 +280,10 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
          return;
       }
 
-      if (chunk_name == png_IDAT)
-         png_ptr->mode |= PNG_HAVE_IDAT;
-
-      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
 
       if (chunk_name == png_PLTE)
          png_ptr->mode |= PNG_HAVE_PLTE;
-
-      else if (chunk_name == png_IDAT)
-      {
-         if (!(png_ptr->mode & PNG_HAVE_IHDR))
-            png_error(png_ptr, "Missing IHDR before IDAT");
-
-         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-             !(png_ptr->mode & PNG_HAVE_PLTE))
-            png_error(png_ptr, "Missing PLTE before IDAT");
-      }
    }
 
 #endif
@@ -295,30 +299,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 
    else if (chunk_name == png_IDAT)
    {
-      /* If we reach an IDAT chunk, this means we have read all of the
-       * header chunks, and we can start reading the image (or if this
-       * is called after the image has been read - we have an error).
-       */
-
-      if (!(png_ptr->mode & PNG_HAVE_IHDR))
-         png_error(png_ptr, "Missing IHDR before IDAT");
-
-      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-          !(png_ptr->mode & PNG_HAVE_PLTE))
-         png_error(png_ptr, "Missing PLTE before IDAT");
-
-      if (png_ptr->mode & PNG_HAVE_IDAT)
-      {
-         if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
-            if (png_ptr->push_length == 0)
-               return;
-
-         if (png_ptr->mode & PNG_AFTER_IDAT)
-            png_benign_error(png_ptr, "Too many IDATs found");
-      }
-
       png_ptr->idat_size = png_ptr->push_length;
-      png_ptr->mode |= PNG_HAVE_IDAT;
       png_ptr->process_mode = PNG_READ_IDAT_MODE;
       png_push_have_info(png_ptr, info_ptr);
       png_ptr->zstream.avail_out =
@@ -556,7 +537,8 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
          png_push_save_buffer(png_ptr);
          return;
       }
-      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
+         PNG_HANDLE_CHUNK_AS_DEFAULT);
    }
 
    png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
@@ -649,7 +631,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       else
          save_size = png_ptr->save_buffer_size;
 
-      png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
+      memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
       length -= save_size;
       ptr += save_size;
       png_ptr->buffer_size -= save_size;
@@ -666,7 +648,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       else
          save_size = png_ptr->current_buffer_size;
 
-      png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
+      memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
       png_ptr->buffer_size -= save_size;
       png_ptr->current_buffer_size -= save_size;
       png_ptr->current_buffer_ptr += save_size;
@@ -715,13 +697,13 @@ png_push_save_buffer(png_structrp png_ptr)
          png_error(png_ptr, "Insufficient memory for save_buffer");
       }
 
-      png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+      memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
       png_free(png_ptr, old_buffer);
       png_ptr->save_buffer_max = new_max;
    }
    if (png_ptr->current_buffer_size)
    {
-      png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
+      memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
          png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
       png_ptr->save_buffer_size += png_ptr->current_buffer_size;
       png_ptr->current_buffer_size = 0;
@@ -976,7 +958,7 @@ png_push_process_row(png_structrp png_ptr)
     * it may not be in the future, so this was changed just to copy the
     * interlaced row count:
     */
-   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+   memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
 
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
    if (png_ptr->transformations)
@@ -1210,7 +1192,7 @@ png_read_push_finish_row(png_structrp png_ptr)
    if (png_ptr->interlaced)
    {
       png_ptr->row_number = 0;
-      png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+      memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
 
       do
       {

pngpriv.h

@@ -170,12 +170,17 @@
  * the functions will be used without definitions.)
  *
  * NOTE: although all the API functions are declared here they are not all
- * actually built!
+ * actually built!  Because the declarations are still made it is necessary to
+ * fake out types that they depend on.
  */
 #ifndef PNG_FP_EXPORT
 #  ifndef PNG_FLOATING_POINT_SUPPORTED
 #     define PNG_FP_EXPORT(ordinal, type, name, args)\
          PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
+      typedef struct png_incomplete png_double;
+      typedef png_double*           png_doublep;
+      typedef const png_double*     png_const_doublep;
+      typedef png_double**          png_doublepp;
 #  endif
 #endif
 #ifndef PNG_FIXED_EXPORT
@@ -276,13 +281,6 @@ typedef const png_uint_16p * png_const_uint_16pp;
 #  define PNG_ZBUF_SIZE 65536L
 #endif
 
-/* 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_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.
@@ -392,15 +390,6 @@ typedef const png_uint_16p * png_const_uint_16pp;
 #  endif
 #endif
 
-/* Prior to 1.6.0 if _WINDOWS_ was defined 'lstrlenA' and 'CopyMemory' were used
- * in place of the ISOC90 functions; this is no longer done in 1.6.0, however
- * the use of png_foo as a macro defined to the C function is retained.
- */
-#define png_strlen  strlen
-#define png_memcmp  memcmp
-#define png_memcpy  memcpy
-#define png_memset  memset
-
 /* These macros may need to be architecture dependent. */
 #define PNG_ALIGN_NONE   0 /* do not use data alignment */
 #define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
@@ -532,8 +521,8 @@ typedef const png_uint_16p * png_const_uint_16pp;
 #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_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
@@ -744,8 +733,13 @@ PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
    /* Free the buffer list used by the compressed write code. */
 #endif
 
-#if defined PNG_FLOATING_POINT_SUPPORTED &&\
-   !defined PNG_FIXED_POINT_MACRO_SUPPORTED
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+   !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
+   (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
+   defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
+   (defined(PNG_sCAL_SUPPORTED) && \
+   defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
 PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
    double fp, png_const_charp text),PNG_EMPTY);
 #endif
@@ -928,8 +922,8 @@ PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
 #endif
 
 #ifdef PNG_WRITE_zTXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp key,
-    png_const_charp text, png_size_t text_len, int compression),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
+    key, png_const_charp text, png_size_t text_len, int compression),PNG_EMPTY);
 #endif
 
 #ifdef PNG_WRITE_iTXt_SUPPORTED
@@ -949,8 +943,8 @@ PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
 #endif
 
 #ifdef PNG_WRITE_pCAL_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr, png_charp purpose,
-    png_int_32 X0, png_int_32 X1, int type, int nparams,
+PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
+    png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
     png_const_charp units, png_charpp params),PNG_EMPTY);
 #endif
 
@@ -971,14 +965,16 @@ PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
 #endif
 
 /* Called when finished processing a row of data */
-PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
+    PNG_EMPTY);
 
 /* Internal use only.   Called before first row of data */
-PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
+    PNG_EMPTY);
 
 /* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
  * array of png_ptr->width pixels.  If the image is not interlaced or this
- * is the final pass this just does a png_memcpy, otherwise the "display" flag
+ * is the final pass this just does a memcpy, otherwise the "display" flag
  * is used to determine whether to copy pixels that are not in the current pass.
  *
  * Because 'png_do_read_interlace' (below) replicates pixels this allows this
@@ -1027,23 +1023,23 @@ PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
 /* Unfilter a row: check the filter value before calling this, there is no point
  * calling it for PNG_FILTER_VALUE_NONE.
  */
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop row_info,
-    png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
 
 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
     png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop row_info,
-    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop row_info,
-    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop row_info,
-    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop row_info,
-    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop row_info,
-    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop row_info,
-    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
 
 /* Choose the best filter to use and filter the row data */
 PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
@@ -1217,111 +1213,120 @@ PNG_INTERNAL_FUNCTION(void,png_do_expand_16,(png_row_infop row_info,
  */
 
 /* Decode the IHDR chunk */
-PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 
 #ifdef PNG_READ_bKGD_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_cHRM_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_gAMA_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_hIST_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_iCCP_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif /* PNG_READ_iCCP_SUPPORTED */
 
 #ifdef PNG_READ_iTXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_oFFs_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_pCAL_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_pHYs_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_sBIT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_sCAL_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_sPLT_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif /* PNG_READ_sPLT_SUPPORTED */
 
 #ifdef PNG_READ_sRGB_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_tEXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_tIME_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_tRNS_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
 #ifdef PNG_READ_zTXt_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr, png_inforp info_ptr,
-    png_uint_32 length),PNG_EMPTY);
-#endif
-
-PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
+PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
 
 PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
     png_uint_32 chunk_name),PNG_EMPTY);
 
-#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_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,(png_structrp png_ptr,
-    png_uint_32 chunk_name),PNG_EMPTY);
+#ifdef PNG_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
+   /* This is the function that gets called for unknown chunks.  The 'keep'
+    * argument is either non-zero for a known chunk that has been set to be
+    * handled as unknown or zero for an unknown chunk.  By default the function
+    * just skips the chunk or errors out if it is critical.
+    */
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
+    (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
+   /* Exactly as the API png_handle_as_unknown() except that the argument is a
+    * 32-bit chunk name, not a string.
+    */
 #endif
+#endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED */
 
 /* Handle the transformations for reading and writing */
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
@@ -1334,7 +1339,8 @@ PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
 #endif
 
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
-PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
+    PNG_EMPTY);
 #endif
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
@@ -1345,26 +1351,31 @@ PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
 PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_push_crc_skip,(png_structrp png_ptr,
     png_uint_32 length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_crc_finish,(png_structrp png_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_crc_finish,(png_structrp png_ptr),
+    PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
+    PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
     png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
     png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
+    PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
    png_inforp info_ptr),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
    png_inforp info_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr, png_bytep row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
+     png_bytep row),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
     png_inforp info_ptr),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
     png_inforp info_ptr),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
+    PNG_EMPTY);
 #  ifdef PNG_READ_tEXt_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
@@ -1395,9 +1406,12 @@ PNG_INTERNAL_FUNCTION(void,png_do_write_intrapixel,(png_row_infop row_info,
 
 /* Added at libpng version 1.6.0 */
 #ifdef PNG_GAMMA_SUPPORTED
-PNG_INTERNAL_FUNCTION(int,png_colorspace_set_gamma,(png_const_structrp png_ptr,
-    png_colorspacerp colorspace, png_fixed_point gAMA, int preferred),
-    PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
+    png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
+   /* Set the colorspace gamma with a value provided by the application or by
+    * the gAMA chunk on read.  The value will override anything set by an ICC
+    * profile.
+    */
 
 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
     png_inforp info_ptr), PNG_EMPTY);
@@ -1425,13 +1439,18 @@ PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
 
 #ifdef PNG_sRGB_SUPPORTED
 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
-   png_colorspacerp colorspace, int intent, int preferred), PNG_EMPTY);
+   png_colorspacerp colorspace, int intent), PNG_EMPTY);
+   /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
+    * flags to write them, if it returns false there was a problem and an error
+    * message has already been output (but the colorspace may still need to be
+    * synced to record the invalid flag).
+    */
 #endif /* sRGB */
 
 #ifdef PNG_iCCP_SUPPORTED
 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
    png_colorspacerp colorspace, png_const_charp name,
-   png_uint_32 profile_length, png_const_bytep profile, int preferred),
+   png_uint_32 profile_length, png_const_bytep profile, int color_type),
    PNG_EMPTY);
    /* The 'name' is used for information only */
 
@@ -1442,19 +1461,21 @@ PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
 PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
    png_colorspacerp colorspace, png_const_charp name,
    png_uint_32 profile_length,
-   png_const_bytep profile /* first 132 bytes only */), PNG_EMPTY);
+   png_const_bytep profile /* first 132 bytes only */, int color_type),
+   PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
    png_colorspacerp colorspace, png_const_charp name,
    png_uint_32 profile_length,
    png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(int,png_icc_set_gAMA_and_cHRM,(
+#ifdef PNG_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
    png_const_structrp png_ptr, png_colorspacerp colorspace,
-   png_const_charp name, png_const_bytep profile, uLong adler, int preferred),
-   PNG_EMPTY);
-   /* 'adler' is the Adler32 checksum of the uncompressed profile data, it may
-    * be 0 to indicate that it is not available.  It is used, if provided, as a
-    * fast check on the profile when checking to see if it is sRGB.
+   png_const_bytep profile, uLong adler), PNG_EMPTY);
+   /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
+    * be zero to indicate that it is not available.  It is used, if provided,
+    * as a fast check on the profile when checking to see if it is sRGB.
     */
+#endif
 #endif /* iCCP */
 
 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
@@ -1550,14 +1571,14 @@ PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
    png_warning_parameters p, png_const_charp message),PNG_EMPTY);
    /* 'message' follows the X/Open approach of using @1, @2 to insert
     * parameters previously supplied using the above functions.  Errors in
-    * specifying the parameters will simple result in garbage substitutions.
+    * specifying the parameters will simply result in garbage substitutions.
     */
 #endif
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 /* Application errors (new in 1.6); use these functions (declared below) for
  * errors in the parameters or order of API function calls on read.  The
- * 'warning' should be used for an error that can be handled completely, the
+ * 'warning' should be used for an error that can be handled completely; the
  * 'error' for one which can be handled safely but which may lose application
  * information or settings.
  *
@@ -1572,7 +1593,7 @@ PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
 PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
    png_const_charp message),PNG_EMPTY);
    /* The application provided invalid parameters to an API function or called
-    * an API function at the wrong time, libpng can completely recovered.
+    * an API function at the wrong time, libpng can completely recover.
     */
 
 PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
@@ -1585,10 +1606,25 @@ PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
 #  define png_app_error(pp,s) png_error(pp,s)
 #endif
 
+PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
+   png_const_charp message, int error),PNG_EMPTY);
+   /* Report a recoverable issue in chunk data.  On read this is used to report
+    * a problem found while reading a particular chunk and the
+    * png_chunk_benign_error or png_chunk_warning function is used as
+    * appropriate.  On write this is used to report an error that comes from
+    * data set via an application call to a png_set_ API and png_app_error or
+    * png_app_warning is used as appropriate.
+    *
+    * The 'error' parameter must have one of the following values:
+    */
+#define PNG_CHUNK_WARNING     0 /* never an error */
+#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
+#define PNG_CHUNK_ERROR       2 /* always an error */
+
 /* ASCII to FP interfaces, currently only implemented if sCAL
  * support is required.
  */
-#if defined(PNG_READ_sCAL_SUPPORTED)
+#if defined(PNG_sCAL_SUPPORTED)
 /* MAX_DIGITS is actually the maximum number of characters in an sCAL
  * width or height, derived from the precision (number of significant
  * digits - a build time settable option) and assumptions about the
@@ -1606,7 +1642,7 @@ PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
    png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
 #endif /* FIXED_POINT */
-#endif /* READ_sCAL */
+#endif /* sCAL */
 
 #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
 /* An internal API to validate the format of a floating point number.
@@ -1630,7 +1666,7 @@ PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
  * NOTE: The dangling E problem.
  *   There is a PNG valid floating point number in the following:
  *
- *       PNG floating point numb1.ers are not greedy.
+ *       PNG floating point numbers are not greedy.
  *
  *   Working this out requires *TWO* character lookahead (because of the
  *   sign), the parser does not do this - it will fail at the 'r' - this
@@ -1681,14 +1717,14 @@ PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
 #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 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
+ * be initialized to 0).  It returns a result code, as above.  There
  * is no point calling the parser any more if it fails to advance to
  * the end of the string - it is stuck on an invalid character (or
  * terminated by '\0').
  *
- * Note that the pointer will consume an E or even an E+ then leave
+ * Note that the pointer will consume an E or even an E+ and then leave
  * a 'maybe' state even though a preceding integer.fraction is valid.
  * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
  * a valid number.  It's possible to recover from this by calling
@@ -1728,22 +1764,28 @@ PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
    png_int_32 divided_by),PNG_EMPTY);
 #endif
 
-#ifdef PNG_READ_GAMMA_SUPPORTED
+#ifdef PNG_GAMMA_SUPPORTED
 /* Calculate a reciprocal - used for gamma values.  This returns
- * 0 if the argument is 0 in order to maintain an undefined value,
+ * 0 if the argument is 0 in order to maintain an undefined value;
  * there are no warnings.
  */
 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
    PNG_EMPTY);
 
+#ifdef PNG_READ_GAMMA_SUPPORTED
 /* The same but gives a reciprocal of the product of two fixed point
  * values.  Accuracy is suitable for gamma calculations but this is
- * not exact - use png_muldiv for that.
+ * not exact - use png_muldiv for that.  Only required at present on read.
  */
 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
    png_fixed_point b),PNG_EMPTY);
 #endif
 
+/* Return true if the gamma value is significantly different from 1.0 */
+PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
+   PNG_EMPTY);
+#endif
+
 #ifdef PNG_READ_GAMMA_SUPPORTED
 /* Internal fixed point gamma correction.  These APIs are called as
  * required to convert single values - they don't need to be fast,
@@ -1754,8 +1796,6 @@ PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
  */
 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
    unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
-   PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
    png_fixed_point gamma_value),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
@@ -1809,15 +1849,29 @@ PNG_INTERNAL_FUNCTION(void,png_safe_warning,(png_structp png_ptr,
 PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
    int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
 
-/* Utility to log an error, this also cleans up the png_image, the function
+/* Utility to log an error; this also cleans up the png_image; the function
  * always returns 0 (false).
  */
 PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
    png_const_charp error_message),PNG_EMPTY);
 
+#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
+/* png_image_free is used by the write code but not exported */
+PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
+#endif /* !SIMPLIFIED_READ */
+
 #endif /* SIMPLIFIED READ/WRITE */
 
-/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+#ifdef PNG_FILTER_OPTIMIZATIONS
+PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+   /* This is the initialization function for hardware specific optimizations,
+    * one implementation (for ARM NEON machines) is contained in
+    * arm/filter_neon.c.  It need not be defined - the generic code will be used
+    * if not.
+    */
+#endif
+
+/* Maintainer: Put new private prototypes here ^ */
 
 #include "pngdebug.h"
 

pngread.c

@@ -91,6 +91,10 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 void PNGAPI
 png_read_info(png_structrp png_ptr, png_inforp info_ptr)
 {
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   int keep;
+#endif
+
    png_debug(1, "in png_read_info");
 
    if (png_ptr == NULL || info_ptr == NULL)
@@ -104,13 +108,30 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr)
       png_uint_32 length = png_read_chunk_header(png_ptr);
       png_uint_32 chunk_name = png_ptr->chunk_name;
 
+      /* IDAT logic needs to happen here to simplify getting the two flags
+       * right.
+       */
+      if (chunk_name == png_IDAT)
+      {
+         if (!(png_ptr->mode & PNG_HAVE_IHDR))
+            png_chunk_error(png_ptr, "Missing IHDR before IDAT");
+
+         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+             !(png_ptr->mode & PNG_HAVE_PLTE))
+            png_chunk_error(png_ptr, "Missing PLTE before IDAT");
+
+         else if (png_ptr->mode & PNG_AFTER_IDAT)
+            png_chunk_benign_error(png_ptr, "Too many IDATs found");
+
+         png_ptr->mode |= PNG_HAVE_IDAT;
+      }
+
+      else if (png_ptr->mode & PNG_HAVE_IDAT)
+         png_ptr->mode |= PNG_AFTER_IDAT;
+
       /* This should be a binary subdivision search or a hash for
        * matching the chunk name rather than a linear search.
        */
-      if (chunk_name == png_IDAT)
-         if (png_ptr->mode & PNG_AFTER_IDAT)
-            png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
-
       if (chunk_name == png_IHDR)
          png_handle_IHDR(png_ptr, info_ptr, length);
 
@@ -118,26 +139,16 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr)
          png_handle_IEND(png_ptr, info_ptr, length);
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      else if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
-         PNG_HANDLE_CHUNK_AS_DEFAULT)
+      else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
       {
-         if (chunk_name == png_IDAT)
-            png_ptr->mode |= PNG_HAVE_IDAT;
-
-         png_handle_unknown(png_ptr, info_ptr, length);
+         png_handle_unknown(png_ptr, info_ptr, length, keep);
 
          if (chunk_name == png_PLTE)
             png_ptr->mode |= PNG_HAVE_PLTE;
 
          else if (chunk_name == png_IDAT)
          {
-            if (!(png_ptr->mode & PNG_HAVE_IHDR))
-               png_error(png_ptr, "Missing IHDR before IDAT");
-
-            else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-                !(png_ptr->mode & PNG_HAVE_PLTE))
-               png_error(png_ptr, "Missing PLTE before IDAT");
-
+            png_ptr->idat_size = 0; /* It has been consumed */
             break;
          }
       }
@@ -147,15 +158,7 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr)
 
       else if (chunk_name == png_IDAT)
       {
-         if (!(png_ptr->mode & PNG_HAVE_IHDR))
-            png_error(png_ptr, "Missing IHDR before IDAT");
-
-         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-             !(png_ptr->mode & PNG_HAVE_PLTE))
-            png_error(png_ptr, "Missing PLTE before IDAT");
-
          png_ptr->idat_size = length;
-         png_ptr->mode |= PNG_HAVE_IDAT;
          break;
       }
 
@@ -245,7 +248,8 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr)
 #endif
 
       else
-         png_handle_unknown(png_ptr, info_ptr, length);
+         png_handle_unknown(png_ptr, info_ptr, length,
+            PNG_HANDLE_CHUNK_AS_DEFAULT);
    }
 }
 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
@@ -474,7 +478,7 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
     * 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);
+   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) &&
@@ -683,6 +687,10 @@ png_read_image(png_structrp png_ptr, png_bytepp image)
 void PNGAPI
 png_read_end(png_structrp png_ptr, png_inforp info_ptr)
 {
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   int keep;
+#endif
+
    png_debug(1, "in png_read_end");
 
    if (png_ptr == NULL)
@@ -691,7 +699,10 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
    /* If png_read_end is called in the middle of reading the rows there may
     * still be pending IDAT data and an owned zstream.  Deal with this here.
     */
-   png_read_finish_IDAT(png_ptr);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   if (!png_chunk_unknown_handling(png_ptr, png_IDAT))
+#endif
+      png_read_finish_IDAT(png_ptr);
 
 #ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
    /* Report invalid palette index; added at libng-1.5.10 */
@@ -712,15 +723,14 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
          png_handle_IEND(png_ptr, info_ptr, length);
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      else if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
-         PNG_HANDLE_CHUNK_AS_DEFAULT)
+      else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
       {
          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);
+         png_handle_unknown(png_ptr, info_ptr, length, keep);
          if (chunk_name == png_PLTE)
             png_ptr->mode |= PNG_HAVE_PLTE;
       }
@@ -825,7 +835,8 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
 #endif
 
       else
-         png_handle_unknown(png_ptr, info_ptr, length);
+         png_handle_unknown(png_ptr, info_ptr, length,
+            PNG_HANDLE_CHUNK_AS_DEFAULT);
    } while (!(png_ptr->mode & PNG_HAVE_IEND));
 }
 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
@@ -866,11 +877,12 @@ png_read_destroy(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->save_buffer);
 #endif
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+#if (defined PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) &&\
+   (defined PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
    png_free(png_ptr, png_ptr->unknown_chunk.data);
 #endif
 
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
    png_free(png_ptr, png_ptr->chunk_list);
 #endif
 
@@ -933,7 +945,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
     * PNG file before the first IDAT (image data chunk).
     */
    png_read_info(png_ptr, info_ptr);
-   if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+   if (info_ptr->height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
       png_error(png_ptr, "Image is too high to process with png_read_png()");
 
    /* -------------- image transformations start here ------------------- */
@@ -1080,7 +1092,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
       png_uint_32 iptr;
 
       info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
-          info_ptr->height * png_sizeof(png_bytep));
+          info_ptr->height * (sizeof (png_bytep)));
       for (iptr=0; iptr<info_ptr->height; iptr++)
          info_ptr->row_pointers[iptr] = NULL;
 
@@ -1169,7 +1181,7 @@ png_image_read_init(png_imagep image)
       /* And set the rest of the structure to NULL to ensure that the various
        * fields are consistent.
        */
-      memset(image, 0, sizeof *image);
+      memset(image, 0, (sizeof *image));
       image->version = PNG_IMAGE_VERSION;
 
       if (png_ptr != NULL)
@@ -1179,11 +1191,11 @@ png_image_read_init(png_imagep image)
          if (info_ptr != NULL)
          {
             png_controlp control = png_voidcast(png_controlp,
-               png_malloc_warn(png_ptr, sizeof *control));
+               png_malloc_warn(png_ptr, (sizeof *control)));
 
             if (control != NULL)
             {
-               png_memset(control, 0, sizeof *control);
+               memset(control, 0, (sizeof *control));
 
                control->png_ptr = png_ptr;
                control->info_ptr = info_ptr;
@@ -1345,6 +1357,10 @@ png_image_begin_read_from_stdio(png_imagep image, FILE* file)
             "png_image_begin_read_from_stdio: invalid argument");
    }
 
+   else if (image != NULL)
+      return png_image_error(image,
+         "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION");
+
    return 0;
 }
 
@@ -1379,6 +1395,10 @@ png_image_begin_read_from_file(png_imagep image, const char *file_name)
             "png_image_begin_read_from_file: invalid argument");
    }
 
+   else if (image != NULL)
+      return png_image_error(image,
+         "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION");
+
    return 0;
 }
 #endif /* PNG_STDIO_SUPPORTED */
@@ -1399,7 +1419,7 @@ png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need)
 
             if (memory != NULL && size >= need)
             {
-               png_memcpy(out, memory, need);
+               memcpy(out, memory, need);
                cp->memory = memory + need;
                cp->size = size - need;
                return;
@@ -1440,6 +1460,10 @@ int PNGAPI png_image_begin_read_from_memory(png_imagep image,
             "png_image_begin_read_from_memory: invalid argument");
    }
 
+   else if (image != NULL)
+      return png_image_error(image,
+         "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION");
+
    return 0;
 }
 
@@ -1476,11 +1500,11 @@ png_image_skip_unused_chunks(png_structrp png_ptr)
        /* Ignore unknown chunks and all other chunks except for the
         * IHDR, PLTE, tRNS, IDAT, and IEND chunks.
         */
-       png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
+       png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER,
          NULL, -1);
 
        /* But do not ignore image data handling chunks */
-       png_set_keep_unknown_chunks(png_ptr, 0 /* PNG_HANDLE_CHUNK_AS_DEFAULT */,
+       png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT,
          chunks_to_process, (sizeof chunks_to_process)/5);
     }
 }
@@ -2525,7 +2549,8 @@ png_image_read_colormap(png_voidp argument)
 
                   /* Compare the newly-created color-map entry with the one the
                    * PNG_CMAP_RGB algorithm will use.  If the two entries don't
-                   * match, add the new one and set this as the background index.
+                   * match, add the new one and set this as the background
+                   * index.
                    */
                   if (memcmp((png_const_bytep)display->colormap +
                         sample_size * cmap_entries,
@@ -3907,7 +3932,7 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
             int result;
             png_image_read_control display;
 
-            png_memset(&display, 0, sizeof display);
+            memset(&display, 0, (sizeof display));
             display.image = image;
             display.buffer = buffer;
             display.row_stride = row_stride;
@@ -3941,6 +3966,10 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
             "png_image_finish_read: invalid argument");
    }
 
+   else if (image != NULL)
+      return png_image_error(image,
+         "png_image_finish_read: damaged PNG_IMAGE_VERSION");
+
    return 0;
 }
 

pngrtran.c

@@ -364,7 +364,7 @@ png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
    if (compose)
    {
       /* And obtain alpha pre-multiplication by composing on black: */
-      png_memset(&png_ptr->background, 0, sizeof png_ptr->background);
+      memset(&png_ptr->background, 0, (sizeof png_ptr->background));
       png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */
       png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
       png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
@@ -423,7 +423,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
       int i;
 
       png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
-          (png_uint_32)(num_palette * png_sizeof(png_byte)));
+          (png_uint_32)(num_palette * (sizeof (png_byte))));
       for (i = 0; i < num_palette; i++)
          png_ptr->quantize_index[i] = (png_byte)i;
    }
@@ -440,7 +440,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
 
          /* Initialize an array to sort colors */
          png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
-             (png_uint_32)(num_palette * png_sizeof(png_byte)));
+             (png_uint_32)(num_palette * (sizeof (png_byte))));
 
          /* Initialize the quantize_sort array */
          for (i = 0; i < num_palette; i++)
@@ -574,9 +574,9 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
 
          /* Initialize palette index arrays */
          png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
-             (png_uint_32)(num_palette * png_sizeof(png_byte)));
+             (png_uint_32)(num_palette * (sizeof (png_byte))));
          png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
-             (png_uint_32)(num_palette * png_sizeof(png_byte)));
+             (png_uint_32)(num_palette * (sizeof (png_byte))));
 
          /* Initialize the sort array */
          for (i = 0; i < num_palette; i++)
@@ -586,7 +586,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
          }
 
          hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
-             png_sizeof(png_dsortp)));
+             (sizeof (png_dsortp))));
 
          num_new_palette = num_palette;
 
@@ -616,7 +616,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
                   {
 
                      t = (png_dsortp)png_malloc_warn(png_ptr,
-                         (png_uint_32)(png_sizeof(png_dsort)));
+                         (png_uint_32)(sizeof (png_dsort)));
 
                      if (t == NULL)
                          break;
@@ -741,12 +741,12 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
       png_size_t num_entries = ((png_size_t)1 << total_bits);
 
       png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
-          (png_uint_32)(num_entries * png_sizeof(png_byte)));
+          (png_uint_32)(num_entries * (sizeof (png_byte))));
 
       distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
-          png_sizeof(png_byte)));
+          (sizeof (png_byte))));
 
-      png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
+      memset(distance, 0xff, num_entries * (sizeof (png_byte)));
 
       for (i = 0; i < num_palette; i++)
       {
@@ -1245,7 +1245,7 @@ png_init_rgb_transformations(png_structrp png_ptr)
             default:
 
             case 8:
-               /* Already 8 bits, fall through */
+               /* FALL THROUGH (Already 8 bits) */
 
             case 16:
                /* Already a full 16 bits */
@@ -3284,7 +3284,7 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
 
       if (row_info->bit_depth == 8)
       {
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
          /* Notice that gamma to/from 1 are not necessarily inverses (if
           * there is an overall gamma correction).  Prior to 1.5.5 this code
           * checked the linearized values for equality; this doesn't match
@@ -3361,7 +3361,7 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
 
       else /* RGB bit_depth == 16 */
       {
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
          if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL)
          {
             png_bytep sp = row;
@@ -3535,12 +3535,12 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
    png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
    png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
    int gamma_shift = png_ptr->gamma_shift;
+   int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
 #endif
 
    png_bytep sp;
    png_uint_32 i;
    png_uint_32 row_width = row_info->width;
-   int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
    int shift;
 
    png_debug(1, "in png_do_compose");
@@ -3753,8 +3753,10 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                         if (v == png_ptr->trans_color.gray)
                         {
                            /* Background is already in screen gamma */
-                           *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
-                           *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+                           *sp = (png_byte)((png_ptr->background.gray >> 8)
+                                & 0xff);
+                           *(sp + 1) = (png_byte)(png_ptr->background.gray
+                                & 0xff);
                         }
 
                         else
@@ -3777,8 +3779,10 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 
                         if (v == png_ptr->trans_color.gray)
                         {
-                           *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
-                           *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+                           *sp = (png_byte)((png_ptr->background.gray >> 8)
+                                & 0xff);
+                           *(sp + 1) = (png_byte)(png_ptr->background.gray
+                                & 0xff);
                         }
                      }
                   }
@@ -3858,9 +3862,12 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                         /* Background is already in screen gamma */
                         *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
                         *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
-                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
-                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
-                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+                                & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green
+                                & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+                                & 0xff);
                         *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
                      }
 
@@ -3901,9 +3908,12 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                      {
                         *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
                         *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
-                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
-                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
-                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+                                & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green
+                                & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+                                & 0xff);
                         *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
                      }
                   }
@@ -3958,7 +3968,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                         *sp = (png_byte)png_ptr->background.gray;
 
                      else if (a < 0xff)
-                        png_composite(*sp, *sp, a, png_ptr->background_1.gray);
+                        png_composite(*sp, *sp, a, png_ptr->background.gray);
                   }
                }
             }
@@ -3986,7 +3996,8 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                      else if (a == 0)
                      {
                         /* Background is already in screen gamma */
-                        *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                        *sp = (png_byte)((png_ptr->background.gray >> 8)
+                                & 0xff);
                         *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
                      }
 
@@ -4016,7 +4027,8 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 
                      if (a == 0)
                      {
-                        *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                        *sp = (png_byte)((png_ptr->background.gray >> 8)
+                                & 0xff);
                         *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
                      }
 
@@ -4025,7 +4037,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                         png_uint_16 g, v;
 
                         g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
-                        png_composite_16(v, g, a, png_ptr->background_1.gray);
+                        png_composite_16(v, g, a, png_ptr->background.gray);
                         *sp = (png_byte)((v >> 8) & 0xff);
                         *(sp + 1) = (png_byte)(v & 0xff);
                      }
@@ -4146,9 +4158,12 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                         /* Background is already in screen gamma */
                         *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
                         *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
-                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
-                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
-                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+                                & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green
+                                & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+                                & 0xff);
                         *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
                      }
 
@@ -4159,14 +4174,16 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                         v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
                         png_composite_16(w, v, a, png_ptr->background_1.red);
                         if (!optimize)
-                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
+                                8];
                         *sp = (png_byte)((w >> 8) & 0xff);
                         *(sp + 1) = (png_byte)(w & 0xff);
 
                         v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
                         png_composite_16(w, v, a, png_ptr->background_1.green);
                         if (!optimize)
-                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
+                                8];
 
                         *(sp + 2) = (png_byte)((w >> 8) & 0xff);
                         *(sp + 3) = (png_byte)(w & 0xff);
@@ -4174,7 +4191,8 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                         v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
                         png_composite_16(w, v, a, png_ptr->background_1.blue);
                         if (!optimize)
-                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
+                                8];
 
                         *(sp + 4) = (png_byte)((w >> 8) & 0xff);
                         *(sp + 5) = (png_byte)(w & 0xff);
@@ -4195,9 +4213,12 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                      {
                         *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
                         *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
-                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
-                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
-                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+                                & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green
+                                & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+                                & 0xff);
                         *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
                      }
 

pngrutil.c

@@ -196,7 +196,7 @@ png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length)
 }
 
 /* Optionally skip data and then check the CRC.  Depending on whether we
- * are reading a ancillary or critical chunk, and how the program has set
+ * are reading an ancillary or critical chunk, and how the program has set
  * things up, we may calculate the CRC on the data and print a message.
  * Returns '1' if there was a CRC error, '0' otherwise.
  */
@@ -211,7 +211,7 @@ png_crc_finish(png_structrp png_ptr, png_uint_32 skip)
       png_uint_32 len;
       png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
 
-      len = sizeof tmpbuf;
+      len = (sizeof tmpbuf);
       if (len > skip)
          len = skip;
       skip -= len;
@@ -282,7 +282,7 @@ png_crc_error(png_structrp png_ptr)
 
 /* Manage the read buffer; this simply reallocates the buffer if it is not small
  * enough (or if it is not allocated).  The routine returns a pointer to the
- * buffer, if an error occurs and 'warn' is set the routine returns NULL, else
+ * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
  * it will call png_error (via png_malloc) on failure.  (warn == 2 means
  * 'silent').
  */
@@ -312,8 +312,16 @@ png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
 
       else if (warn < 2) /* else silent */
       {
-         (warn ? png_chunk_warning : png_chunk_error)(png_ptr,
-            "insufficient memory to read chunk");
+#ifdef PNG_WARNINGS_SUPPORTED
+         if (warn)
+             png_chunk_warning(png_ptr, "insufficient memory to read chunk");
+         else
+#endif
+         {
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+             png_chunk_error(png_ptr, "insufficient memory to read chunk");
+#endif
+         }
       }
    }
 
@@ -337,7 +345,7 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner, int window_bits)
        * internal error, but is very useful for debugging.  i18n requirements
        * are minimal.
        */
-      (void)png_safecat(msg, sizeof msg, 4, " using zstream");
+      (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
 #     if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
          png_chunk_warning(png_ptr, msg);
          png_ptr->zowner = 0;
@@ -349,11 +357,11 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner, int window_bits)
    /* Implementation note: unlike 'png_deflate_claim' this internal function
     * does not take the size of the data as an argument.  Some efficiency could
     * be gained by using this when it is known *if* the zlib stream itself does
-    * not record the number, however this is a chimera: the original writer of
-    * the PNG may have selected a lower window size, and we really must follow
-    * that because, for systems with with limited capabilities, we would
-    * otherwise reject the applications attempts to use a smaller window size.
-    * (zlib doesn't have an interface to say "this or lower"!)
+    * not record the number; however, this is an illusion: the original writer
+    * follow of the PNG may have selected a lower window size, and we really
+    * must do that because, for systems with with limited capabilities, we
+    * would otherwise reject the application's attempts to use a smaller window
+    * size (zlib doesn't have an interface to say "this or lower"!).
     *
     * inflateReset2 was added to zlib 1.2.4; before this the window could not be
     * reset, therefore it is necessary to always allocate the maximum window
@@ -455,7 +463,7 @@ png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
           * inside it is possible to chunk the input to zlib and simply rely on
           * zlib to advance the 'next_in' pointer.  This allows arbitrary
           * amounts of data to be passed through zlib at the unavoidable cost of
-          * requiring a window save (png_memcpy of up to 32768 output bytes)
+          * requiring a window save (memcpy of up to 32768 output bytes)
           * every ZLIB_IO_MAX input bytes.
           */
          avail_in += png_ptr->zstream.avail_in; /* not consumed last time */
@@ -479,8 +487,8 @@ png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
              * make available the full buffer, up to 'remaining_space'
              */
             png_ptr->zstream.next_out = local_buffer;
-            if (sizeof local_buffer < avail)
-               avail = sizeof local_buffer;
+            if ((sizeof local_buffer) < avail)
+               avail = (sizeof local_buffer);
          }
 
          if (avail_out < avail)
@@ -566,7 +574,7 @@ png_decompress_chunk(png_structrp png_ptr,
    if (limit >= prefix_size + (terminate != 0))
    {
       int ret;
-      
+
       limit -= prefix_size + (terminate != 0);
 
       if (limit < *newlength)
@@ -588,7 +596,7 @@ png_decompress_chunk(png_structrp png_ptr,
          ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
             /* input: */ png_ptr->read_buffer + prefix_size, &lzsize,
             /* output: */ NULL, newlength);
-          
+
          if (ret == Z_STREAM_END)
          {
             /* Use 'inflateReset' here, not 'inflateReset2' because this
@@ -625,7 +633,7 @@ png_decompress_chunk(png_structrp png_ptr,
                            text[prefix_size + *newlength] = 0;
 
                         if (prefix_size > 0)
-                           png_memcpy(text, png_ptr->read_buffer, prefix_size);
+                           memcpy(text, png_ptr->read_buffer, prefix_size);
 
                         {
                            png_bytep old_ptr = png_ptr->read_buffer;
@@ -1001,7 +1009,7 @@ png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
     * maintainers to ignore it.
     */
 #ifdef PNG_READ_tRNS_SUPPORTED
-   if (png_ptr->num_trans > 0 || 
+   if (png_ptr->num_trans > 0 ||
       (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0))
    {
       /* Cancel this because otherwise it would be used if the transforms
@@ -1079,31 +1087,7 @@ png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
 
    igamma = png_get_fixed_point(NULL, buf);
 
-   /* The gAMA value is unsigned (and is a power law correction, so 0 is
-    * meaningless.)
-    */
-   if (igamma <= 0)
-   {
-      png_chunk_benign_error(png_ptr, "out of range");
-      return;
-   }
-
-   /* If a colorspace error has already been output skip this chunk */
-   if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
-      return;
-
-   if (png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA)
-   {
-      png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
-      png_colorspace_sync(png_ptr, info_ptr);
-
-      png_chunk_benign_error(png_ptr, "duplicate");
-      return;
-   }
-
-   png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_gAMA;
-   (void)png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma,
-      1/*prefer gAMA values*/);
+   png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma);
    png_colorspace_sync(png_ptr, info_ptr);
 }
 #endif
@@ -1277,13 +1261,6 @@ png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
    if (png_crc_finish(png_ptr, 0))
       return;
 
-   /* Check for bad intent */
-   if (intent >= PNG_sRGB_INTENT_LAST)
-   {
-      png_chunk_benign_error(png_ptr, "Unknown sRGB intent");
-      return;
-   }
-
    /* If a colorspace error has already been output skip this chunk */
    if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
       return;
@@ -1299,16 +1276,7 @@ png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
       return;
    }
 
-   /* Do not override gAMA or cHRM from the PNG file; just check they match.
-    * This is because we write a cHRM which corresponds to D65, however there is
-    * an issue with CMMs that assume a D50 environment that requires adaptation
-    * of the white point.  This way at least it is possible to supply an
-    * adapated value (so long as it is within the tolerance limits for a match
-    * against the D65 chromaticities.)
-    *
-    * TODO: get expert opinions on this issue
-    */
-   (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent, 0);
+   (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent);
    png_colorspace_sync(png_ptr, info_ptr);
 }
 #endif /* PNG_READ_sRGB_SUPPORTED */
@@ -1394,12 +1362,12 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
             {
                Byte profile_header[132];
                Byte local_buffer[PNG_INFLATE_BUF_SIZE];
-               png_alloc_size_t size = sizeof profile_header;
+               png_alloc_size_t size = (sizeof profile_header);
 
                png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2);
                png_ptr->zstream.avail_in = read_length;
                (void)png_inflate_read(png_ptr, local_buffer,
-                  sizeof local_buffer, &length, profile_header, &size,
+                  (sizeof local_buffer), &length, profile_header, &size,
                   0/*finish: don't, because the output is too small*/);
 
                if (size == 0)
@@ -1416,7 +1384,8 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
                       * byte header.
                       */
                      if (png_icc_check_header(png_ptr, &png_ptr->colorspace,
-                        keyword, profile_length, profile_header))
+                        keyword, profile_length, profile_header,
+                        png_ptr->color_type))
                      {
                         /* Now read the tag table; a variable size buffer is
                          * needed at this point, allocate one for the whole
@@ -1431,12 +1400,12 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
                         if (profile != NULL)
                         {
                            memcpy(profile, profile_header,
-                              sizeof profile_header);
+                              (sizeof profile_header));
 
                            size = 12 * tag_count;
 
                            (void)png_inflate_read(png_ptr, local_buffer,
-                              sizeof local_buffer, &length,
+                              (sizeof local_buffer), &length,
                               profile + (sizeof profile_header), &size, 0);
 
                            /* Still expect a a buffer error because we expect
@@ -1455,7 +1424,7 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
                                     - 12 * tag_count;
 
                                  (void)png_inflate_read(png_ptr, local_buffer,
-                                    sizeof local_buffer, &length,
+                                    (sizeof local_buffer), &length,
                                     profile + (sizeof profile_header) +
                                     12 * tag_count, &size, 1/*finish*/);
 
@@ -1466,8 +1435,6 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
                                  /* But otherwise allow extra data: */
                                  else if (size == 0)
                                  {
-                                    int ok;
-
                                     if (length > 0)
                                     {
                                        /* This can be handled completely, so
@@ -1480,17 +1447,15 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
                                     png_crc_finish(png_ptr, length);
                                     finished = 1;
 
-                                    /* Set the gAMA and cHRM information, this
-                                     * checks for a known sRGB profile.  The
-                                     * result is 0 on error.
-                                     */
-                                    ok = png_icc_set_gAMA_and_cHRM(png_ptr,
-                                       &png_ptr->colorspace, keyword, profile,
-                                       png_ptr->zstream.adler,
-                                       0/*prefer explicit gAMA/cHRM*/);
+#                                   ifdef PNG_sRGB_SUPPORTED
+                                       /* Check for a match against sRGB */
+                                       png_icc_set_sRGB(png_ptr,
+                                          &png_ptr->colorspace, profile,
+                                          png_ptr->zstream.adler);
+#                                   endif
 
                                     /* Steal the profile for info_ptr. */
-                                    if (ok && info_ptr != NULL)
+                                    if (info_ptr != NULL)
                                     {
                                        png_free_data(png_ptr, info_ptr,
                                           PNG_FREE_ICCP, 0);
@@ -1526,15 +1491,11 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
                                     if (info_ptr != NULL)
                                        png_colorspace_sync(png_ptr, info_ptr);
 
-                                    if (errmsg == NULL && ok)
+                                    if (errmsg == NULL)
                                     {
                                        png_ptr->zowner = 0;
                                        return;
                                     }
-
-                                    /* else png_icc_set_gAMA_and_cHRM has
-                                     * already output an error.
-                                     */
                                  }
 
                                  else if (size > 0)
@@ -1579,7 +1540,7 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
       else
          errmsg = "bad keyword";
    }
-   
+
    else
       errmsg = "too many profiles";
 
@@ -1694,7 +1655,7 @@ png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
    }
 
    dl = (png_int_32)(data_length / entry_size);
-   max_dl = PNG_SIZE_MAX / png_sizeof(png_sPLT_entry);
+   max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry));
 
    if (dl > max_dl)
    {
@@ -1705,7 +1666,7 @@ png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
    new_palette.nentries = (png_int_32)(data_length / entry_size);
 
    new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
-       png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
+       png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry)));
 
    if (new_palette.entries == NULL)
    {
@@ -2211,7 +2172,7 @@ png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
    png_debug(3, "Allocating pCAL parameters array");
 
    params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
-       nparams * png_sizeof(png_charp)));
+       nparams * (sizeof (png_charp))));
 
    if (params == NULL)
    {
@@ -2458,7 +2419,7 @@ png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
    text_info.lang_key = NULL;
    text_info.itxt_length = 0;
    text_info.text = text;
-   text_info.text_length = png_strlen(text);
+   text_info.text_length = strlen(text);
 
    if (png_set_text_2(png_ptr, info_ptr, &text_info, 1))
       png_warning(png_ptr, "Insufficient memory to process text chunk");
@@ -2724,136 +2685,261 @@ png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
 }
 #endif
 
-/* This function is called when we haven't found a handler for a
- * chunk.  If there isn't a problem with the chunk itself (ie bad
- * chunk name, CRC, or a critical chunk), the chunk is silently ignored
- * -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
- * case it will be saved away to be written out later.
- */
-void /* PRIVATE */
-png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
-   png_uint_32 length)
-{
-   png_uint_32 skip = 0;
-
-   png_debug(1, "in png_handle_unknown");
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
-   if (png_ptr->user_chunk_cache_max != 0)
-   {
-      if (png_ptr->user_chunk_cache_max == 1)
-      {
-         png_crc_finish(png_ptr, length);
-         return;
-      }
-
-      if (--png_ptr->user_chunk_cache_max == 1)
-      {
-         png_crc_finish(png_ptr, length);
-         png_chunk_benign_error(png_ptr, "no space in chunk cache");
-         return;
-      }
-   }
-#endif
-
-   if (png_ptr->mode & PNG_HAVE_IDAT)
-   {
-      if (png_ptr->chunk_name != png_IDAT)
-         png_ptr->mode |= PNG_AFTER_IDAT;
-   }
-
-   if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
-   {
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      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
-#endif
-          )
-#endif
-         png_chunk_error(png_ptr, "unknown critical chunk");
-   }
-
 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-   if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
-#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
-       || (png_ptr->read_user_chunk_fn != NULL)
-#endif
-       )
-   {
-#ifdef PNG_MAX_MALLOC_64K
-      if (length > 65535)
-      {
-         png_crc_finish(png_ptr, length);
-         png_chunk_benign_error(png_ptr,
-            "unknown chunk too large to fit in memory");
-         return;
-      }
-#endif
+/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
+static int
+png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
+{
+   png_alloc_size_t limit = PNG_SIZE_MAX;
 
-      /* 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.
-       */
+   if (png_ptr->unknown_chunk.data != NULL)
+   {
+      png_free(png_ptr, png_ptr->unknown_chunk.data);
+      png_ptr->unknown_chunk.data = NULL;
+   }
+
+#  ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+      if (png_ptr->user_chunk_malloc_max > 0 &&
+         png_ptr->user_chunk_malloc_max < limit)
+         limit = png_ptr->user_chunk_malloc_max;
+
+#  elif PNG_USER_CHUNK_MALLOC_MAX > 0
+      if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+         limit = PNG_USER_CHUNK_MALLOC_MAX;
+#  endif
+
+   if (length <= limit)
+   {
       PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
-      png_ptr->unknown_chunk.size = (png_size_t)length;
+      /* The following is safe because of the PNG_SIZE_MAX init above */
+      png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/;
+      /* 'mode' is a flag array, only the bottom four bits matter here */
+      png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/;
 
       if (length == 0)
          png_ptr->unknown_chunk.data = NULL;
 
       else
       {
-         png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
-         png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
+         /* Do a 'warn' here - it is handled below. */
+         png_ptr->unknown_chunk.data = png_voidcast(png_bytep,
+            png_malloc_warn(png_ptr, length));
       }
+   }
 
-#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
-      if (png_ptr->read_user_chunk_fn != NULL)
-      {
-         /* Callback to user unknown chunk handler */
-         int ret;
-
-         ret = (*(png_ptr->read_user_chunk_fn))
-             (png_ptr, &png_ptr->unknown_chunk);
-
-         if (ret < 0)
-            png_chunk_error(png_ptr, "error in user chunk");
-
-         if (ret == 0)
-         {
-            if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
-            {
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-               if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
-                   PNG_HANDLE_CHUNK_ALWAYS)
-#endif
-                  png_chunk_error(png_ptr, "unknown critical chunk");
-            }
-
-            png_set_unknown_chunks(png_ptr, info_ptr,
-                &png_ptr->unknown_chunk, 1);
-         }
-      }
-
-      else
-#endif
-         png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
-
-      png_free(png_ptr, png_ptr->unknown_chunk.data);
-      png_ptr->unknown_chunk.data = NULL;
+   if (png_ptr->unknown_chunk.data == NULL && length > 0)
+   {
+      /* This is benign because we clean up correctly */
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits");
+      return 0;
    }
 
    else
-#endif
-      skip = length;
+   {
+      if (length > 0)
+         png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
+      png_crc_finish(png_ptr, 0);
+      return 1;
+   }
+}
+#endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
 
-   png_crc_finish(png_ptr, skip);
+/* Handle an unknown, or known but disabled, chunk */
+void /* PRIVATE */
+png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
+   png_uint_32 length, int keep)
+{
+   int handled = 0; /* the chunk was handled */
 
-#ifndef PNG_READ_USER_CHUNKS_SUPPORTED
-   PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
-#endif
+   png_debug(1, "in png_handle_unknown");
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
+    * the bug which meant that setting a non-default behavior for a specific
+    * chunk would be ignored (the default was always used unless a user
+    * callback was installed).
+    *
+    * 'keep' is the value from the png_chunk_unknown_handling, the setting for
+    * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it
+    * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here.
+    * This is just an optimization to avoid multiple calls to the lookup
+    * function.
+    */
+#  ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#     ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+         keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
+#     endif
+#  endif
+
+   /* One of the following methods will read the chunk or skip it (at least one
+    * of these is always defined because this is the only way to switch on
+    * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+    */
+#  ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+      /* The user callback takes precedence over the chunk keep value, but the
+       * keep value is still required to validate a save of a critical chunk.
+       */
+      if (png_ptr->read_user_chunk_fn != NULL)
+      {
+         if (png_cache_unknown_chunk(png_ptr, length))
+         {
+            /* Callback to user unknown chunk handler */
+            int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr,
+               &png_ptr->unknown_chunk);
+
+            /* ret is:
+             * negative: An error occured, png_chunk_error will be called.
+             *     zero: The chunk was not handled, the chunk will be discarded
+             *           unless png_set_keep_unknown_chunks has been used to set
+             *           a 'keep' behavior for this particular chunk, in which
+             *           case that will be used.  A critical chunk will cause an
+             *           error at this point unless it is to be saved.
+             * positive: The chunk was handled, libpng will ignore/discard it.
+             */
+            if (ret < 0)
+               png_chunk_error(png_ptr, "error in user chunk");
+
+            else if (ret == 0)
+            {
+               /* If the keep value is 'default' or 'never' override it, but
+                * still error out on critical chunks unless the keep value is
+                * 'always'  While this is weird it is the behavior in 1.4.12.  A
+                * possible improvement would be to obey the value set for the
+                * chunk, but this would be an API change that would probably
+                * damage some applications.
+                *
+                * The png_app_warning below catches the case that matters, where
+                * the application has neither set specific save for this chunk
+                * or global save.
+                */
+               if (keep < PNG_HANDLE_CHUNK_IF_SAFE)
+               {
+#                 ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+                     if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE)
+                        png_app_warning(png_ptr,
+ "forcing save of an unhandled chunk; please call png_set_keep_unknown_chunks");
+#                 endif
+                  keep = PNG_HANDLE_CHUNK_IF_SAFE;
+               }
+            }
+
+            else /* chunk was handled */
+            {
+               handled = 1;
+               /* Critical chunks can be safely discarded at this point. */
+               keep = PNG_HANDLE_CHUNK_NEVER;
+            }
+         }
+
+         else
+            keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */
+      }
+
+      else
+         /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */
+#  endif /* PNG_READ_USER_CHUNKS_SUPPORTED */
+
+#  ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+      {
+         /* keep is currently just the per-chunk setting, if there was no
+          * setting change it to the global default now (not that this may
+          * still be AS_DEFAULT) then obtain the cache of the chunk if required,
+          * if not simply skip the chunk.
+          */
+         if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
+            keep = png_ptr->unknown_default;
+
+         if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+            (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+             PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name)))
+         {
+            if (!png_cache_unknown_chunk(png_ptr, length))
+               keep = PNG_HANDLE_CHUNK_NEVER;
+         }
+
+         else
+            png_crc_finish(png_ptr, length);
+      }
+#  else
+#     ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+#        error no method to support READ_UNKNOWN_CHUNKS
+#     endif
+
+      {
+         /* If here there is no read callback pointer set and no support is
+          * compiled in to just save the unknown chunks, so simply skip this
+          * chunk.  If 'keep' is something other than AS_DEFAULT or NEVER then
+          * the app has erroneously asked for unknown chunk saving when there
+          * is no support.
+          */
+         if (keep > PNG_HANDLE_CHUNK_NEVER)
+            png_app_error(png_ptr, "no unknown chunk support available");
+
+         png_crc_finish(png_ptr, length);
+      }
+#  endif
+
+#  ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+      /* Now store the chunk in the chunk list if appropriate, and if the limits
+       * permit it.
+       */
+      if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+         (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+          PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name)))
+      {
+#     ifdef PNG_USER_LIMITS_SUPPORTED
+         switch (png_ptr->user_chunk_cache_max)
+         {
+            case 2:
+               png_ptr->user_chunk_cache_max = 1;
+               png_chunk_benign_error(png_ptr, "no space in chunk cache");
+               /* FALL THROUGH */
+            case 1:
+               /* NOTE: prior to 1.6.0 this case resulted in an unknown critical
+                * chunk being skipped, now there will be a hard error below.
+                */
+               break;
+
+            default: /* not at limit */
+               --(png_ptr->user_chunk_cache_max);
+               /* FALL THROUGH */
+            case 0: /* no limit */
+#     endif /* PNG_USER_LIMITS_SUPPORTED */
+               /* Here when the limit isn't reached or when limits are compiled
+                * out; store the chunk.
+                */
+               png_set_unknown_chunks(png_ptr, info_ptr,
+                  &png_ptr->unknown_chunk, 1);
+               handled = 1;
+#     ifdef PNG_USER_LIMITS_SUPPORTED
+               break;
+         }
+#     endif
+      }
+#  else /* no store support! */
+      PNG_UNUSED(info_ptr)
+#     error untested code (reading unknown chunks with no store support)
+#  endif
+
+   /* Regardless of the error handling below the cached data (if any) can be
+    * freed now.  Notice that the data is not freed if there is a png_error, but
+    * it will be freed by destroy_read_struct.
+    */
+   if (png_ptr->unknown_chunk.data != NULL)
+      png_free(png_ptr, png_ptr->unknown_chunk.data);
+   png_ptr->unknown_chunk.data = NULL;
+
+#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
+   /* There is no support to read an unknown chunk, so just skip it. */
+   png_crc_finish(png_ptr, length);
+   PNG_UNUSED(info_ptr)
+   PNG_UNUSED(keep)
+#endif /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
+
+   /* Check for unhandled critical chunks */
+   if (!handled && PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+      png_chunk_error(png_ptr, "unhandled critical chunk");
 }
 
 /* This function is called to verify that a chunk name is valid.
@@ -2944,7 +3030,7 @@ png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
       /* end_mask is now the bits to *keep* from the destination row */
    }
 
-   /* For non-interlaced images this reduces to a png_memcpy(). A png_memcpy()
+   /* For non-interlaced images this reduces to a memcpy(). A memcpy()
     * will also happen if interlacing isn't supported or if the application
     * does not call png_set_interlace_handling().  In the latter cases the
     * caller just gets a sequence of the unexpanded rows from each interlace
@@ -3245,27 +3331,27 @@ png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
                /* Check for double byte alignment and, if possible, use a
                 * 16-bit copy.  Don't attempt this for narrow images - ones that
                 * are less than an interlace panel wide.  Don't attempt it for
-                * wide bytes_to_copy either - use the png_memcpy there.
+                * wide bytes_to_copy either - use the memcpy there.
                 */
-               if (bytes_to_copy < 16 /*else use png_memcpy*/ &&
+               if (bytes_to_copy < 16 /*else use memcpy*/ &&
                   png_isaligned(dp, png_uint_16) &&
                   png_isaligned(sp, png_uint_16) &&
-                  bytes_to_copy % sizeof (png_uint_16) == 0 &&
-                  bytes_to_jump % sizeof (png_uint_16) == 0)
+                  bytes_to_copy % (sizeof (png_uint_16)) == 0 &&
+                  bytes_to_jump % (sizeof (png_uint_16)) == 0)
                {
                   /* Everything is aligned for png_uint_16 copies, but try for
                    * png_uint_32 first.
                    */
                   if (png_isaligned(dp, png_uint_32) &&
                      png_isaligned(sp, png_uint_32) &&
-                     bytes_to_copy % sizeof (png_uint_32) == 0 &&
-                     bytes_to_jump % sizeof (png_uint_32) == 0)
+                     bytes_to_copy % (sizeof (png_uint_32)) == 0 &&
+                     bytes_to_jump % (sizeof (png_uint_32)) == 0)
                   {
                      png_uint_32p dp32 = png_aligncast(png_uint_32p,dp);
                      png_const_uint_32p sp32 = png_aligncastconst(
                         png_const_uint_32p, sp);
                      unsigned int skip = (bytes_to_jump-bytes_to_copy) /
-                        sizeof (png_uint_32);
+                        (sizeof (png_uint_32));
 
                      do
                      {
@@ -3273,7 +3359,7 @@ png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
                         do
                         {
                            *dp32++ = *sp32++;
-                           c -= sizeof (png_uint_32);
+                           c -= (sizeof (png_uint_32));
                         }
                         while (c > 0);
 
@@ -3307,7 +3393,7 @@ png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
                      png_const_uint_16p sp16 = png_aligncastconst(
                         png_const_uint_16p, sp);
                      unsigned int skip = (bytes_to_jump-bytes_to_copy) /
-                        sizeof (png_uint_16);
+                        (sizeof (png_uint_16));
 
                      do
                      {
@@ -3315,7 +3401,7 @@ png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
                         do
                         {
                            *dp16++ = *sp16++;
-                           c -= sizeof (png_uint_16);
+                           c -= (sizeof (png_uint_16));
                         }
                         while (c > 0);
 
@@ -3339,10 +3425,10 @@ png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
                }
 #endif /* PNG_ALIGN_ code */
 
-               /* The true default - use a png_memcpy: */
+               /* The true default - use a memcpy: */
                for (;;)
                {
-                  png_memcpy(dp, sp, bytes_to_copy);
+                  memcpy(dp, sp, bytes_to_copy);
 
                   if (row_width <= bytes_to_jump)
                      return;
@@ -3363,11 +3449,11 @@ png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
    else
 #endif
 
-   /* If here then the switch above wasn't used so just png_memcpy the whole row
+   /* If here then the switch above wasn't used so just memcpy the whole row
     * from the temporary row buffer (notice that this overwrites the end of the
     * destination row if it is a partial byte.)
     */
-   png_memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
+   memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
 
    /* Restore the overwritten bits from the last byte if necessary. */
    if (end_ptr != NULL)
@@ -3596,11 +3682,11 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
                png_byte v[8];
                int j;
 
-               png_memcpy(v, sp, pixel_bytes);
+               memcpy(v, sp, pixel_bytes);
 
                for (j = 0; j < jstop; j++)
                {
-                  png_memcpy(dp, v, pixel_bytes);
+                  memcpy(dp, v, pixel_bytes);
                   dp -= pixel_bytes;
                }
 
@@ -3777,68 +3863,16 @@ png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
    }
 }
 
-#ifdef PNG_ARM_NEON
-
-#ifdef __linux__
-#include <stdio.h>
-#include <elf.h>
-#include <asm/hwcap.h>
-
-static int png_have_hwcap(unsigned cap)
-{
-   FILE *f = fopen("/proc/self/auxv", "r");
-   Elf32_auxv_t aux;
-   int have_cap = 0;
-
-   if (!f)
-      return 0;
-
-   while (fread(&aux, sizeof(aux), 1, f) > 0)
-   {
-      if (aux.a_type == AT_HWCAP &&
-          aux.a_un.a_val & cap)
-      {
-         have_cap = 1;
-         break;
-      }
-   }
-
-   fclose(f);
-
-   return have_cap;
-}
-#endif /* __linux__ */
-
-static void
-png_init_filter_functions_neon(png_structrp pp, unsigned int bpp)
-{
-#ifdef __linux__
-   if (!png_have_hwcap(HWCAP_NEON))
-      return;
-#endif
-
-   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
-
-   if (bpp == 3)
-   {
-      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
-      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
-      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
-         png_read_filter_row_paeth3_neon;
-   }
-
-   else if (bpp == 4)
-   {
-      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
-      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
-      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
-          png_read_filter_row_paeth4_neon;
-   }
-}
-#endif /* PNG_ARM_NEON */
-
 static void
 png_init_filter_functions(png_structrp pp)
+   /* This function is called once for every PNG image to set the
+    * implementations required to reverse the filtering of PNG rows.  Reversing
+    * the filter is the first transformation performed on the row data.  It is
+    * performed in place, therefore an implementation can be selected based on
+    * the image pixel format.  If the implementation depends on image width then
+    * take care to ensure that it works corretly if the image is interlaced -
+    * interlacing causes the actual row width to vary.
+    */
 {
    unsigned int bpp = (pp->pixel_depth + 7) >> 3;
 
@@ -3852,8 +3886,16 @@ png_init_filter_functions(png_structrp pp)
       pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
          png_read_filter_row_paeth_multibyte_pixel;
 
-#ifdef PNG_ARM_NEON
-   png_init_filter_functions_neon(pp, bpp);
+#ifdef PNG_FILTER_OPTIMIZATIONS
+   /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to
+    * call to install hardware optimizations for the above functions; simply
+    * replace whatever elements of the pp->read_filter[] array with a hardware
+    * specific (or, for that matter, generic) optimization.
+    *
+    * To see an example of this examine what configure.ac does when
+    * --enable-arm-neon is specified on the command line.
+    */
+   PNG_FILTER_OPTIMIZATIONS(pp, bpp);
 #endif
 }
 
@@ -3861,6 +3903,10 @@ void /* PRIVATE */
 png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row,
    png_const_bytep prev_row, int filter)
 {
+   /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define
+    * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic
+    * implementations.  See png_init_filter_functions above.
+    */
    if (pp->read_filter[0] == NULL)
       png_init_filter_functions(pp);
    if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
@@ -3935,7 +3981,7 @@ png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
       else /* check for end */
       {
          png_ptr->zstream.next_out = tmpbuf;
-         png_ptr->zstream.avail_out = sizeof tmpbuf;
+         png_ptr->zstream.avail_out = (sizeof tmpbuf);
       }
 
       /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the
@@ -4074,7 +4120,7 @@ png_read_finish_row(png_structrp png_ptr)
       /* TO DO: don't do this if prev_row isn't needed (requires
        * read-ahead of the next row's filter byte.
        */
-      png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+      memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
 
       do
       {
@@ -4372,7 +4418,7 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
    if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
       png_error(png_ptr, "Row has too many bytes to allocate in memory");
 
-   png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+   memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
 
    png_debug1(3, "width = %u,", png_ptr->width);
    png_debug1(3, "height = %u,", png_ptr->height);

pngset.c

@@ -80,15 +80,15 @@ png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
    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;
+   XYZ.red_X = int_red_X;
+   XYZ.red_Y = int_red_Y;
+   XYZ.red_Z = int_red_Z;
+   XYZ.green_X = int_green_X;
+   XYZ.green_Y = int_green_Y;
+   XYZ.green_Z = int_green_Z;
+   XYZ.blue_X = int_blue_X;
+   XYZ.blue_Y = int_blue_Y;
+   XYZ.blue_Z = int_blue_Z;
 
    if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace, &XYZ, 2))
       info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
@@ -143,25 +143,8 @@ png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   /* 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 gamma values (and will produce
-    * displays that are all black or all white.)
-    */
-   if (file_gamma < 16 || file_gamma > 625000000)
-      png_app_error(png_ptr, "Out of range gamma value ignored");
-
-   else
-   {
-      if (png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma,
-         2/* overrided with app value */))
-         info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_gAMA;
-
-      png_colorspace_sync_info(png_ptr, info_ptr);
-   }
+   png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma);
+   png_colorspace_sync_info(png_ptr, info_ptr);
 }
 
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
@@ -201,7 +184,7 @@ png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
     * version 1.2.1
     */
    info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr,
-       PNG_MAX_PALETTE_LENGTH * png_sizeof(png_uint_16)));
+       PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16))));
 
    if (info_ptr->hist == NULL)
    {
@@ -299,7 +282,7 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
       || (nparams > 0 && params == NULL))
       return;
 
-   length = png_strlen(purpose) + 1;
+   length = strlen(purpose) + 1;
    png_debug1(3, "allocating purpose for info (%lu bytes)",
        (unsigned long)length);
 
@@ -315,7 +298,7 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
    /* Validate params[nparams] */
    for (i=0; i<nparams; ++i)
       if (params[i] == NULL ||
-         !png_check_fp_string(params[i], png_strlen(params[i])))
+         !png_check_fp_string(params[i], strlen(params[i])))
          png_error(png_ptr, "Invalid format for pCAL parameter");
 
    info_ptr->pcal_purpose = png_voidcast(png_charp,
@@ -327,7 +310,7 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
       return;
    }
 
-   png_memcpy(info_ptr->pcal_purpose, purpose, length);
+   memcpy(info_ptr->pcal_purpose, purpose, length);
 
    png_debug(3, "storing X0, X1, type, and nparams in info");
    info_ptr->pcal_X0 = X0;
@@ -335,7 +318,7 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
    info_ptr->pcal_type = (png_byte)type;
    info_ptr->pcal_nparams = (png_byte)nparams;
 
-   length = png_strlen(units) + 1;
+   length = strlen(units) + 1;
    png_debug1(3, "allocating units for info (%lu bytes)",
      (unsigned long)length);
 
@@ -348,10 +331,10 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
       return;
    }
 
-   png_memcpy(info_ptr->pcal_units, units, length);
+   memcpy(info_ptr->pcal_units, units, length);
 
    info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
-       (png_size_t)((nparams + 1) * png_sizeof(png_charp))));
+       (png_size_t)((nparams + 1) * (sizeof (png_charp)))));
 
    if (info_ptr->pcal_params == NULL)
    {
@@ -359,11 +342,11 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
       return;
    }
 
-   png_memset(info_ptr->pcal_params, 0, (nparams + 1) * png_sizeof(png_charp));
+   memset(info_ptr->pcal_params, 0, (nparams + 1) * (sizeof (png_charp)));
 
    for (i = 0; i < nparams; i++)
    {
-      length = png_strlen(params[i]) + 1;
+      length = strlen(params[i]) + 1;
       png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
           (unsigned long)length);
 
@@ -375,7 +358,7 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
          return;
       }
 
-      png_memcpy(info_ptr->pcal_params[i], params[i], length);
+      memcpy(info_ptr->pcal_params[i], params[i], length);
    }
 
    info_ptr->valid |= PNG_INFO_pCAL;
@@ -401,11 +384,11 @@ png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
    if (unit != 1 && unit != 2)
       png_error(png_ptr, "Invalid sCAL unit");
 
-   if (swidth == NULL || (lengthw = png_strlen(swidth)) == 0 ||
+   if (swidth == NULL || (lengthw = 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 ||
+   if (sheight == NULL || (lengthh = strlen(sheight)) == 0 ||
        sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
       png_error(png_ptr, "Invalid sCAL height");
 
@@ -424,7 +407,7 @@ png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
       return;
    }
 
-   png_memcpy(info_ptr->scal_s_width, swidth, lengthw);
+   memcpy(info_ptr->scal_s_width, swidth, lengthw);
 
    ++lengthh;
 
@@ -442,7 +425,7 @@ png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
       return;
    }
 
-   png_memcpy(info_ptr->scal_s_height, sheight, lengthh);
+   memcpy(info_ptr->scal_s_height, sheight, lengthh);
 
    info_ptr->valid |= PNG_INFO_sCAL;
    info_ptr->free_me |= PNG_FREE_SCAL;
@@ -468,9 +451,9 @@ png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
       char swidth[PNG_sCAL_MAX_DIGITS+1];
       char sheight[PNG_sCAL_MAX_DIGITS+1];
 
-      png_ascii_from_fp(png_ptr, swidth, sizeof swidth, width,
+      png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width,
          PNG_sCAL_PRECISION);
-      png_ascii_from_fp(png_ptr, sheight, sizeof sheight, height,
+      png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height,
          PNG_sCAL_PRECISION);
 
       png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
@@ -498,8 +481,8 @@ png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
       char swidth[PNG_sCAL_MAX_DIGITS+1];
       char sheight[PNG_sCAL_MAX_DIGITS+1];
 
-      png_ascii_from_fixed(png_ptr, swidth, sizeof swidth, width);
-      png_ascii_from_fixed(png_ptr, sheight, sizeof sheight, height);
+      png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width);
+      png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height);
 
       png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
    }
@@ -560,9 +543,9 @@ png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
     * too-large sample values.
     */
    png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
-       PNG_MAX_PALETTE_LENGTH * png_sizeof(png_color)));
+       PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));
 
-   png_memcpy(png_ptr->palette, palette, num_palette * png_sizeof(png_color));
+   memcpy(png_ptr->palette, palette, num_palette * (sizeof (png_color)));
    info_ptr->palette = png_ptr->palette;
    info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
 
@@ -595,9 +578,7 @@ png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent,
-      2/* app value overrides*/);
-
+   (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent);
    png_colorspace_sync_info(png_ptr, info_ptr);
 }
 
@@ -610,10 +591,9 @@ png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent,
-      2/* app value overrides*/))
+   if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent))
    {
-      /* And cause the gAMA and cHRM to be written too */
+      /* This causes the gAMA and cHRM to be written too */
       info_ptr->colorspace.flags |=
          PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
    }
@@ -643,11 +623,13 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
 
    /* Set the colorspace first because this validates the profile; do not
     * override previously set app cHRM or gAMA here (because likely as not the
-    * application knows better than libpng what the correct values are.)
+    * application knows better than libpng what the correct values are.)  Pass
+    * the info_ptr color_type field to png_colorspace_set_ICC because in the
+    * write case it has not yet been stored in png_ptr.
     */
    {
       int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name,
-         proflen, profile, 0/* do *not* override the app cHRM or gAMA */);
+         proflen, profile, info_ptr->color_type);
 
       png_colorspace_sync_info(png_ptr, info_ptr);
 
@@ -660,7 +642,7 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
          PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
    }
 
-   length = png_strlen(name)+1;
+   length = strlen(name)+1;
    new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));
 
    if (new_iccp_name == NULL)
@@ -669,7 +651,7 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
       return;
    }
 
-   png_memcpy(new_iccp_name, name, length);
+   memcpy(new_iccp_name, name, length);
    new_iccp_profile = png_voidcast(png_bytep,
       png_malloc_warn(png_ptr, proflen));
 
@@ -681,7 +663,7 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
       return;
    }
 
-   png_memcpy(new_iccp_profile, profile, proflen);
+   memcpy(new_iccp_profile, profile, proflen);
 
    png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
 
@@ -733,7 +715,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
          old_text = info_ptr->text;
 
          info_ptr->text = (png_textp)png_malloc_warn(png_ptr,
-            (png_size_t)(info_ptr->max_text * png_sizeof(png_text)));
+            (png_size_t)(info_ptr->max_text * (sizeof (png_text))));
 
          if (info_ptr->text == NULL)
          {
@@ -743,8 +725,8 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
             return(1);
          }
 
-         png_memcpy(info_ptr->text, old_text, (png_size_t)(old_max_text *
-             png_sizeof(png_text)));
+         memcpy(info_ptr->text, old_text, (png_size_t)(old_max_text *
+             (sizeof (png_text))));
          png_free(png_ptr, old_text);
       }
 
@@ -753,7 +735,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
          info_ptr->max_text = num_text + 8;
          info_ptr->num_text = 0;
          info_ptr->text = (png_textp)png_malloc_warn(png_ptr,
-             (png_size_t)(info_ptr->max_text * png_sizeof(png_text)));
+             (png_size_t)(info_ptr->max_text * (sizeof (png_text))));
          if (info_ptr->text == NULL)
          {
             /* Restore to previous condition */
@@ -783,7 +765,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
          continue;
       }
 
-      key_len = png_strlen(text_ptr[i].key);
+      key_len = strlen(text_ptr[i].key);
 
       if (text_ptr[i].compression <= 0)
       {
@@ -797,13 +779,13 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
          /* Set iTXt data */
 
          if (text_ptr[i].lang != NULL)
-            lang_len = png_strlen(text_ptr[i].lang);
+            lang_len = strlen(text_ptr[i].lang);
 
          else
             lang_len = 0;
 
          if (text_ptr[i].lang_key != NULL)
-            lang_key_len = png_strlen(text_ptr[i].lang_key);
+            lang_key_len = strlen(text_ptr[i].lang_key);
 
          else
             lang_key_len = 0;
@@ -829,7 +811,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
 
       else
       {
-         text_length = png_strlen(text_ptr[i].text);
+         text_length = strlen(text_ptr[i].text);
          textp->compression = text_ptr[i].compression;
       }
 
@@ -845,16 +827,16 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
           (key_len + lang_len + lang_key_len + text_length + 4),
           textp->key);
 
-      png_memcpy(textp->key, text_ptr[i].key,(png_size_t)(key_len));
+      memcpy(textp->key, text_ptr[i].key,(png_size_t)(key_len));
       *(textp->key + key_len) = '\0';
 
       if (text_ptr[i].compression > 0)
       {
          textp->lang = textp->key + key_len + 1;
-         png_memcpy(textp->lang, text_ptr[i].lang, lang_len);
+         memcpy(textp->lang, text_ptr[i].lang, lang_len);
          *(textp->lang + lang_len) = '\0';
          textp->lang_key = textp->lang + lang_len + 1;
-         png_memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
+         memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
          *(textp->lang_key + lang_key_len) = '\0';
          textp->text = textp->lang_key + lang_key_len + 1;
       }
@@ -867,7 +849,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
       }
 
       if (text_length)
-         png_memcpy(textp->text, text_ptr[i].text,
+         memcpy(textp->text, text_ptr[i].text,
              (png_size_t)(text_length));
 
       *(textp->text + text_length) = '\0';
@@ -946,7 +928,7 @@ png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
          png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
 
        if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
-          png_memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
+          memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
    }
 
    if (trans_color != NULL)
@@ -999,7 +981,7 @@ png_set_sPLT(png_const_structrp png_ptr,
       return;
 
    np = png_voidcast(png_sPLT_tp, png_malloc_warn(png_ptr,
-       (info_ptr->splt_palettes_num + nentries) * png_sizeof(png_sPLT_t)));
+       (info_ptr->splt_palettes_num + nentries) * (sizeof (png_sPLT_t))));
 
    if (np == NULL)
    {
@@ -1007,8 +989,8 @@ png_set_sPLT(png_const_structrp png_ptr,
       return;
    }
 
-   png_memcpy(np, info_ptr->splt_palettes,
-       info_ptr->splt_palettes_num * png_sizeof(png_sPLT_t));
+   memcpy(np, info_ptr->splt_palettes,
+       info_ptr->splt_palettes_num * (sizeof (png_sPLT_t)));
 
    png_free(png_ptr, info_ptr->splt_palettes);
    info_ptr->splt_palettes=NULL;
@@ -1026,12 +1008,12 @@ png_set_sPLT(png_const_structrp png_ptr,
        * NULL, otherwise libpng will crash later on while trying to free the
        * uninitialized pointers.
        */
-      png_memset(to, 0, sizeof *to);
+      memset(to, 0, (sizeof *to));
 
       if (from->name == NULL || from->entries == NULL)
          continue;
 
-      length = png_strlen(from->name) + 1;
+      length = strlen(from->name) + 1;
       to->name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));
 
       if (to->name == NULL)
@@ -1041,9 +1023,9 @@ png_set_sPLT(png_const_structrp png_ptr,
          continue;
       }
 
-      png_memcpy(to->name, from->name, length);
+      memcpy(to->name, from->name, length);
       to->entries = png_voidcast(png_sPLT_entryp, png_malloc_warn(png_ptr,
-          from->nentries * png_sizeof(png_sPLT_entry)));
+          from->nentries * (sizeof (png_sPLT_entry))));
 
       if (to->entries == NULL)
       {
@@ -1053,8 +1035,8 @@ png_set_sPLT(png_const_structrp png_ptr,
          continue;
       }
 
-      png_memcpy(to->entries, from->entries,
-          from->nentries * png_sizeof(png_sPLT_entry));
+      memcpy(to->entries, from->entries,
+          from->nentries * (sizeof (png_sPLT_entry)));
 
       to->nentries = from->nentries;
       to->depth = from->depth;
@@ -1067,79 +1049,144 @@ png_set_sPLT(png_const_structrp png_ptr,
 }
 #endif /* PNG_sPLT_SUPPORTED */
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+static png_byte
+check_location(png_const_structrp png_ptr, int location)
+{
+   location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);
+
+   /* New in 1.6.0; copy the location and check it.  This is an API
+    * change, previously the app had to use the
+    * png_set_unknown_chunk_location API below for each chunk.
+    */
+   if (location == 0 && !(png_ptr->mode & PNG_IS_READ_STRUCT))
+   {
+      /* Write struct, so unknown chunks come from the app */
+      png_app_warning(png_ptr,
+         "png_set_unknown_chunks now expects a valid location");
+      /* Use the old behavior */
+      location = (png_byte)(png_ptr->mode &
+         (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
+   }
+
+   if (location == 0)
+      png_error(png_ptr, "invalid location in png_set_unknown_chunks");
+
+   /* Now reduce the location to the top-most set bit by removing each least
+    * significant bit in turn.
+    */
+   while (location != (location & -location))
+      location &= ~(location & -location);
+
+   /* The cast is safe because 'location' is a bit mask and only the low four
+    * bits are significant.
+    */
+   return (png_byte)location;
+}
+
 void PNGAPI
 png_set_unknown_chunks(png_const_structrp png_ptr,
    png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
 {
    png_unknown_chunkp np;
-   int i;
 
-   if (png_ptr == NULL || info_ptr == NULL || num_unknowns == 0)
+   if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0)
       return;
 
-   np = png_voidcast(png_unknown_chunkp, png_malloc_warn(png_ptr,
-       (png_size_t)(info_ptr->unknown_chunks_num + num_unknowns) *
-       png_sizeof(png_unknown_chunk)));
+   /* Check for the failure cases where support has been disabled at compile
+    * time.  This code is hardly ever compiled - it's here because
+    * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this
+    * code) but may be meaningless if the read or write handling of unknown
+    * chunks is not compiled in.
+    */
+#  if !(defined PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
+      (defined PNG_READ_SUPPORTED)
+      if (png_ptr->mode & PNG_IS_READ_STRUCT)
+      {
+         png_app_error(png_ptr, "no unknown chunk support on read");
+         return;
+      }
+#  endif
+#  if !(defined PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
+      (defined PNG_WRITE_SUPPORTED)
+      if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
+      {
+         png_app_error(png_ptr, "no unknown chunk support on write");
+         return;
+      }
+#  endif
 
-   if (np == NULL)
-   {
-      png_warning(png_ptr,
-          "Out of memory while processing unknown chunk");
-      return;
-   }
+   /* Prior to 1.6.0 this code used png_malloc_warn, however this meant that
+    * unknown critical chunks could be lost with just a warning resulting in
+    * undefined behavior.  Changing to png_malloc fixes this by producing a
+    * png_error.  The (png_size_t) cast was also removed as it hides a potential
+    * overflow.
+    *
+    * TODO: fix the potential overflow in the multiply
+    */
+   np = png_voidcast(png_unknown_chunkp, png_malloc(png_ptr,
+       (info_ptr->unknown_chunks_num + (unsigned int)num_unknowns) *
+       (sizeof (png_unknown_chunk))));
 
-   png_memcpy(np, info_ptr->unknown_chunks,
-       (png_size_t)info_ptr->unknown_chunks_num *
-       png_sizeof(png_unknown_chunk));
+   memcpy(np, info_ptr->unknown_chunks,
+       info_ptr->unknown_chunks_num * (sizeof (png_unknown_chunk)));
 
    png_free(png_ptr, info_ptr->unknown_chunks);
-   info_ptr->unknown_chunks = NULL;
+   info_ptr->unknown_chunks = np; /* safe because it is initialized */
+   info_ptr->free_me |= PNG_FREE_UNKN;
 
-   for (i = 0; i < num_unknowns; i++)
+   np += info_ptr->unknown_chunks_num;
+
+   /* Increment unknown_chunks_num each time round the loop to protect the
+    * just-allocated chunk data.
+    */
+   for (; --num_unknowns >= 0;
+      ++np, ++unknowns, ++(info_ptr->unknown_chunks_num))
    {
-      png_unknown_chunkp to = np + info_ptr->unknown_chunks_num + i;
-      png_const_unknown_chunkp from = unknowns + i;
+      memcpy(np->name, unknowns->name, (sizeof unknowns->name));
+      np->name[(sizeof np->name)-1] = '\0';
+      np->size = unknowns->size;
+      np->location = check_location(png_ptr, unknowns->location);
 
-      png_memcpy(to->name, from->name, png_sizeof(from->name));
-      to->name[png_sizeof(to->name)-1] = '\0';
-      to->size = from->size;
-
-      /* Note our location in the read or write sequence */
-      to->location = (png_byte)png_ptr->mode;
-
-      if (from->size == 0)
-         to->data=NULL;
+      if (unknowns->size == 0)
+         np->data = NULL;
 
       else
       {
-         to->data = (png_bytep)png_malloc_warn(png_ptr,
-             (png_size_t)from->size);
-
-         if (to->data == NULL)
-         {
-            png_warning(png_ptr,
-                "Out of memory while processing unknown chunk");
-            to->size = 0;
-         }
-
-         else
-            png_memcpy(to->data, from->data, from->size);
+         /* png_error is safe here because the list is stored in png_ptr */
+         np->data = png_voidcast(png_bytep,
+            png_malloc(png_ptr, unknowns->size));
+         memcpy(np->data, unknowns->data, unknowns->size);
       }
    }
-
-   info_ptr->unknown_chunks = np;
-   info_ptr->unknown_chunks_num += num_unknowns;
-   info_ptr->free_me |= PNG_FREE_UNKN;
 }
 
 void PNGAPI
 png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
     int chunk, int location)
 {
-   if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 && chunk <
-       info_ptr->unknown_chunks_num)
-      info_ptr->unknown_chunks[chunk].location = (png_byte)location;
+   /* This API is pretty pointless in 1.6.0 because the location can be set
+    * before the call to png_set_unknown_chunks.
+    *
+    * TODO: add a png_app_warning in 1.7
+    */
+   if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
+      (unsigned int)chunk < info_ptr->unknown_chunks_num)
+   {
+      if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0)
+      {
+         png_app_error(png_ptr, "invalid unknown chunk location");
+         /* Fake out the pre 1.6.0 behavior: */
+         if ((location & PNG_HAVE_IDAT)) /* undocumented! */
+            location = PNG_AFTER_IDAT;
+
+         else
+            location = PNG_HAVE_IHDR; /* also undocumented */
+      }
+
+      info_ptr->unknown_chunks[chunk].location =
+         check_location(png_ptr, location);
+   }
 }
 #endif
 
@@ -1160,88 +1207,177 @@ png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features)
 #endif
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+static unsigned int
+add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep)
+{
+   unsigned int i;
+
+   /* Utility function: update the 'keep' state of a chunk if it is already in
+    * the list, otherwise add it to the list.
+    */
+   for (i=0; i<count; ++i, list += 5) if (memcmp(list, add, 4) == 0)
+   {
+      list[4] = (png_byte)keep;
+      return count;
+   }
+
+   if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
+   {
+      ++count;
+      memcpy(list, add, 4);
+      list[4] = (png_byte)keep;
+   }
+
+   return count;
+}
+
 void PNGAPI
 png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
-    png_const_bytep chunk_list, int num_chunksIn)
+    png_const_bytep chunk_list, int num_chunks_in)
 {
-   png_bytep new_list, p;
-   unsigned int i, num_chunks, old_num_chunks;
+   png_bytep new_list;
+   unsigned int num_chunks, old_num_chunks;
+
    if (png_ptr == NULL)
       return;
 
-   if (num_chunksIn <= 0)
+   if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST)
    {
-      if (keep == PNG_HANDLE_CHUNK_ALWAYS || keep == PNG_HANDLE_CHUNK_IF_SAFE)
-         png_ptr->flags |= PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+      png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");
+      return;
+   }
 
-      else
-         png_ptr->flags &= ~PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+   if (num_chunks_in <= 0)
+   {
+      png_ptr->unknown_default = keep;
 
-      if (keep == PNG_HANDLE_CHUNK_ALWAYS)
-         png_ptr->flags |= PNG_FLAG_KEEP_UNSAFE_CHUNKS;
-
-      else
-         png_ptr->flags &= ~PNG_FLAG_KEEP_UNSAFE_CHUNKS;
-
-      if (num_chunksIn == 0)
+      /* '0' means just set the flags, so stop here */
+      if (num_chunks_in == 0)
         return;
    }
 
-   if (num_chunksIn < 0)
-      {
-         /* Ignore all unknown chunks and all chunks recognized by
-          * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
-          */
-         static PNG_CONST png_byte chunks_to_ignore[] = {
-            98,  75,  71,  68, '\0',  /* bKGD */
-            99,  72,  82,  77, '\0',  /* cHRM */
-           103,  65,  77,  65, '\0',  /* gAMA */
-           104,  73,  83,  84, '\0',  /* hIST */
-           105,  67,  67,  80, '\0',  /* iCCP */
-           105,  84,  88, 116, '\0',  /* iTXt */
-           111,  70,  70, 115, '\0',  /* oFFs */
-           112,  67,  65,  76, '\0',  /* pCAL */
-           112,  72,  89, 115, '\0',  /* pHYs */
-           115,  66,  73,  84, '\0',  /* sBIT */
-           115,  67,  65,  76, '\0',  /* sCAL */
-           115,  80,  76,  84, '\0',  /* sPLT */
-           115,  84,  69,  82, '\0',  /* sTER */
-           115,  82,  71,  66, '\0',  /* sRGB */
-           116,  69,  88, 116, '\0',  /* tEXt */
-           116,  73,  77,  69, '\0',  /* tIME */
-           122,  84,  88, 116, '\0'   /* zTXt */
-           };
-
-         chunk_list = chunks_to_ignore;
-         num_chunks = (unsigned int) sizeof(chunks_to_ignore)/5;
-       }
-
-   if (chunk_list == NULL)
-      return;
-
-   if (num_chunksIn > 0)
-     num_chunks = (unsigned int)num_chunksIn;
-
-   old_num_chunks = png_ptr->num_chunk_list;
-   new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
-       5 * (num_chunks + old_num_chunks)));
-
-   if (png_ptr->chunk_list != NULL)
+   if (num_chunks_in < 0)
    {
-      png_memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
-      png_free(png_ptr, png_ptr->chunk_list);
-      png_ptr->chunk_list=NULL;
+      /* Ignore all unknown chunks and all chunks recognized by
+       * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
+       */
+      static PNG_CONST png_byte chunks_to_ignore[] = {
+         98,  75,  71,  68, '\0',  /* bKGD */
+         99,  72,  82,  77, '\0',  /* cHRM */
+        103,  65,  77,  65, '\0',  /* gAMA */
+        104,  73,  83,  84, '\0',  /* hIST */
+        105,  67,  67,  80, '\0',  /* iCCP */
+        105,  84,  88, 116, '\0',  /* iTXt */
+        111,  70,  70, 115, '\0',  /* oFFs */
+        112,  67,  65,  76, '\0',  /* pCAL */
+        112,  72,  89, 115, '\0',  /* pHYs */
+        115,  66,  73,  84, '\0',  /* sBIT */
+        115,  67,  65,  76, '\0',  /* sCAL */
+        115,  80,  76,  84, '\0',  /* sPLT */
+        115,  84,  69,  82, '\0',  /* sTER */
+        115,  82,  71,  66, '\0',  /* sRGB */
+        116,  69,  88, 116, '\0',  /* tEXt */
+        116,  73,  77,  69, '\0',  /* tIME */
+        122,  84,  88, 116, '\0'   /* zTXt */
+      };
+
+      chunk_list = chunks_to_ignore;
+      num_chunks = (sizeof chunks_to_ignore)/5;
    }
 
-   png_memcpy(new_list + 5*old_num_chunks, chunk_list,
-      5*(unsigned int)num_chunks);
+   else /* num_chunks_in > 0 */
+   {
+      if (chunk_list == NULL)
+      {
+         /* Prior to 1.6.0 this was silently ignored, now it is an app_error
+          * which can be switched off.
+          */
+         png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
+         return;
+      }
 
-   for (p = new_list + 5*old_num_chunks + 4, i = 0; i<num_chunks; i++, p += 5)
-      *p=(png_byte)keep;
+      num_chunks = num_chunks_in;
+   }
 
-   png_ptr->num_chunk_list = old_num_chunks + num_chunks;
-   png_ptr->chunk_list = new_list;
-   png_ptr->free_me |= PNG_FREE_LIST;
+   old_num_chunks = png_ptr->num_chunk_list;
+   if (png_ptr->chunk_list == NULL)
+      old_num_chunks = 0;
+
+   /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
+    */
+   if (num_chunks + old_num_chunks > UINT_MAX/5)
+   {
+      png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
+      return;
+   }
+
+   /* If these chunks are being reset to the default then no more memory is
+    * required because add_one_chunk above doesn't extend the list if the 'keep'
+    * parameter is the default.
+    */
+   if (keep)
+   {
+      new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
+          5 * (num_chunks + old_num_chunks)));
+
+      if (old_num_chunks > 0)
+         memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
+   }
+
+   else if (old_num_chunks > 0)
+      new_list = png_ptr->chunk_list;
+
+   else
+      new_list = NULL;
+
+   /* Add the new chunks together with each one's handling code.  If the chunk
+    * already exists the code is updated, otherwise the chunk is added to the
+    * end.  (In libpng 1.6.0 order no longer matters because this code enforces
+    * the earlier convention that the last setting is the one that is used.)
+    */
+   if (new_list != NULL)
+   {
+      png_const_bytep inlist;
+      png_bytep outlist;
+      unsigned int i;
+
+      for (i=0; i<num_chunks; ++i)
+         old_num_chunks = add_one_chunk(new_list, old_num_chunks,
+            chunk_list+5*i, keep);
+
+      /* Now remove any spurious 'default' entries. */
+      num_chunks = 0;
+      for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
+         if (inlist[4])
+         {
+            if (outlist != inlist)
+               memcpy(outlist, inlist, 5);
+            outlist += 5;
+            ++num_chunks;
+         }
+
+      /* This means the application has removed all the specialized handling. */
+      if (num_chunks == 0)
+      {
+         if (png_ptr->chunk_list != new_list)
+            png_free(png_ptr, new_list);
+
+         new_list = NULL;
+      }
+   }
+
+   else
+      num_chunks = 0;
+
+   png_ptr->num_chunk_list = num_chunks;
+
+   if (png_ptr->chunk_list != new_list)
+   {
+      if (png_ptr->chunk_list != NULL)
+         png_free(png_ptr, png_ptr->chunk_list);
+
+      png_ptr->chunk_list = new_list;
+   }
 }
 #endif
 
@@ -1306,14 +1442,14 @@ png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
               "Compression buffer size cannot be changed because it is in use");
             return;
          }
-  
+
          if (size > ZLIB_IO_MAX)
          {
             png_warning(png_ptr,
                "Compression buffer size limited to system maximum");
             size = ZLIB_IO_MAX; /* must fit */
          }
-  
+
          else if (size < 6)
          {
             /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
@@ -1323,7 +1459,7 @@ png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
                "Compression buffer size cannot be reduced below 6");
             return;
          }
-  
+
          if (png_ptr->zbuffer_size != size)
          {
             png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
@@ -1400,7 +1536,14 @@ png_set_benign_errors(png_structrp png_ptr, int allowed)
 #endif /* PNG_BENIGN_ERRORS_SUPPORTED */
 
 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-   /* Do not report invalid palette index; added at libng-1.5.10 */
+   /* Whether to report invalid palette index; added at libng-1.5.10.
+    * It is possible for an indexed (color-type==3) PNG file to contain
+    * pixels with invalid (out-of-range) indexes if the PLTE chunk has
+    * fewer entries than the image's bit-depth would allow. We recover
+    * from this gracefully by filling any incomplete palette with zeroes
+    * (opaque black).  By default, when this occurs libpng will issue
+    * a benign error.  This API can be used to override that behavior.
+    */
 void PNGAPI
 png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
 {
@@ -1413,5 +1556,4 @@ png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
       png_ptr->num_palette_max = -1;
 }
 #endif
-
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */

pngstruct.h

@@ -94,9 +94,9 @@ typedef struct png_xy
  */
 typedef struct png_XYZ
 {
-   png_fixed_point redX, redY, redZ;
-   png_fixed_point greenX, greenY, greenZ;
-   png_fixed_point blueX, blueY, blueZ;
+   png_fixed_point red_X, red_Y, red_Z;
+   png_fixed_point green_X, green_Y, green_Z;
+   png_fixed_point blue_X, blue_Y, blue_Z;
 } png_XYZ;
 #endif /* COLORSPACE */
 
@@ -128,13 +128,15 @@ typedef struct png_colorspace
 
 typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
 
+/* General flags for the 'flags' field */
 #define PNG_COLORSPACE_HAVE_GAMMA           0x0001
 #define PNG_COLORSPACE_HAVE_ENDPOINTS       0x0002
 #define PNG_COLORSPACE_HAVE_INTENT          0x0004
 #define PNG_COLORSPACE_FROM_gAMA            0x0008
 #define PNG_COLORSPACE_FROM_cHRM            0x0010
-#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0020
-#define PNG_COLORSPACE_MATCHES_sRGB         0x0040 /* exact match on profile */
+#define PNG_COLORSPACE_FROM_sRGB            0x0020
+#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
+#define PNG_COLORSPACE_MATCHES_sRGB         0x0080 /* exact match on profile */
 #define PNG_COLORSPACE_INVALID              0x8000
 #define PNG_COLORSPACE_CANCEL(flags)        (0xffff ^ (flags))
 #endif /* COLORSPACE || GAMMA */
@@ -252,7 +254,9 @@ struct png_struct_def
    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 */
+#ifdef PNG_WRITE_SUPPORTED
    png_byte usr_channels;     /* channels at start of write: write only */
+#endif
    png_byte sig_bytes;        /* magic bytes read/written from start of file */
    png_byte maximum_pixel_depth;
                               /* pixel depth used for the row buffers */
@@ -366,12 +370,16 @@ struct png_struct_def
 
 #ifdef PNG_USER_CHUNKS_SUPPORTED
    png_voidp user_chunk_ptr;
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
    png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
 #endif
+#endif
 
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   unsigned int num_chunk_list;
-   png_bytep chunk_list;
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   int          unknown_default; /* As PNG_HANDLE_* */
+   unsigned int num_chunk_list;  /* Number of entries in the list */
+   png_bytep    chunk_list;      /* List of png_byte[5]; the textual chunk name
+                                  * followed by a PNG_HANDLE_* byte */
 #endif
 
 /* New members added in libpng-1.0.3 */
@@ -436,14 +444,12 @@ struct png_struct_def
 #endif
 
 /* New member added in libpng-1.0.25 and 1.2.17 */
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
    /* Temporary storage for unknown chunk that the library doesn't recognize,
     * used while reading the chunk.
     */
-#ifdef PNG_READ_SUPPORTED
    png_unknown_chunk unknown_chunk;
 #endif
-#endif
 
 /* New member added in libpng-1.2.26 */
   png_size_t old_big_row_buf_size;

pngtest.c

@@ -33,16 +33,23 @@
 
 #define _POSIX_SOURCE 1
 
-#include "zlib.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Defined so I can write to a file on gui/windowing platforms */
+/*  #define STDERR stderr  */
+#define STDERR stdout   /* For DOS */
+
 #include "png.h"
+
+#ifdef PNG_READ_SUPPORTED /* else nothing can be done */
+#include "zlib.h"
 /* Copied from pngpriv.h but only used in error messages below. */
 #ifndef PNG_ZBUF_SIZE
 #  define PNG_ZBUF_SIZE 8192
 #endif
-#  include <stdio.h>
-#  include <stdlib.h>
-#  include <string.h>
-#  define FCLOSE(file) fclose(file)
+#define FCLOSE(file) fclose(file)
 
 #ifndef PNG_STDIO_SUPPORTED
 typedef FILE                * png_FILE_p;
@@ -88,20 +95,31 @@ static char tIME_string[PNG_tIME_STRING_LENGTH] = "tIME chunk is not present";
 
 static int verbose = 0;
 static int strict = 0;
+static int relaxed = 0;
+static int unsupported_chunks = 0; /* chunk unsupported by libpng in input */
+static int error_count = 0; /* count calls to png_error */
+static int warning_count = 0; /* count calls to png_warning */
 
 #ifdef __TURBOC__
 #include <mem.h>
 #endif
 
-/* Defined so I can write to a file on gui/windowing platforms */
-/*  #define STDERR stderr  */
-#define STDERR stdout   /* For DOS */
-
 /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
 #ifndef png_jmpbuf
 #  define png_jmpbuf(png_ptr) png_ptr->jmpbuf
 #endif
 
+/* Defines for unknown chunk handling if required. */
+#ifndef PNG_HANDLE_CHUNK_ALWAYS
+#  define PNG_HANDLE_CHUNK_ALWAYS       3
+#endif
+#ifndef PNG_HANDLE_CHUNK_IF_SAFE
+#  define PNG_HANDLE_CHUNK_IF_SAFE      2
+#endif
+
+/* Utility to save typing/errors, the argument must be a name */
+#define MEMZERO(var) ((void)memset(&var, 0, sizeof var))
+
 /* Example of using row callbacks to make a simple progress meter */
 static int status_pass = 1;
 static int status_dots_requested = 0;
@@ -131,6 +149,7 @@ read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
    fprintf(stdout, "r");
 }
 
+#ifdef PNG_WRITE_SUPPORTED
 static void PNGCBAPI
 write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
 {
@@ -139,6 +158,7 @@ write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
 
    fprintf(stdout, "w");
 }
+#endif
 
 
 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
@@ -269,8 +289,6 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
 }
 #endif /* PNG_WRITE_USER_TRANSFORM_SUPPORTED */
 
-static int wrote_question = 0;
-
 #ifndef PNG_STDIO_SUPPORTED
 /* START of code to validate stdio-free compilation */
 /* These copies of the default read/write functions come from pngrio.c and
@@ -378,24 +396,31 @@ pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
    pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING);
 #endif
 }
+#endif /* !PNG_STDIO_SUPPORTED */
 
 /* This function is called when there is a warning, but the library thinks
  * it can continue anyway.  Replacement functions don't have to do anything
  * here if you don't want to.  In the default configuration, png_ptr is
  * not used, but it is passed in case it may be useful.
  */
+typedef struct
+{
+   PNG_CONST char *file_name;
+}  pngtest_error_parameters;
+
 static void PNGCBAPI
 pngtest_warning(png_structp png_ptr, png_const_charp message)
 {
    PNG_CONST char *name = "UNKNOWN (ERROR!)";
-   char *test;
-   test = png_get_error_ptr(png_ptr);
+   pngtest_error_parameters *test =
+      (pngtest_error_parameters*)png_get_error_ptr(png_ptr);
 
-   if (test == NULL)
-     fprintf(STDERR, "%s: libpng warning: %s\n", name, message);
+   ++warning_count;
 
-   else
-     fprintf(STDERR, "%s: libpng warning: %s\n", test, message);
+   if (test != NULL && test->file_name != NULL)
+      name = test->file_name;
+
+   fprintf(STDERR, "%s: libpng warning: %s\n", name, message);
 }
 
 /* This is the default error handling function.  Note that replacements for
@@ -406,12 +431,14 @@ pngtest_warning(png_structp png_ptr, png_const_charp message)
 static void PNGCBAPI
 pngtest_error(png_structp png_ptr, png_const_charp message)
 {
+   ++error_count;
+
    pngtest_warning(png_ptr, message);
    /* We can return because png_error calls the default handler, which is
     * actually OK in this case.
     */
 }
-#endif /* !PNG_STDIO_SUPPORTED */
+
 /* END of code to validate stdio-free compilation */
 
 /* START of code to validate memory allocation and deallocation */
@@ -462,7 +489,7 @@ PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size)
       memory_infop pinfo;
       png_set_mem_fn(png_ptr, NULL, NULL, NULL);
       pinfo = (memory_infop)png_malloc(png_ptr,
-         png_sizeof(*pinfo));
+         (sizeof *pinfo));
       pinfo->size = size;
       current_allocation += size;
       total_allocation += size;
@@ -556,25 +583,73 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
 /* END of code to test memory allocation/deallocation */
 
 
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
 /* Demonstration of user chunk support of the sTER and vpAg chunks */
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
 
 /* (sTER is a public chunk not yet known by libpng.  vpAg is a private
 chunk used in ImageMagick to store "virtual page" size).  */
 
-static png_uint_32 user_chunk_data[4];
+static struct user_chunk_data
+{
+   png_const_infop info_ptr;
+   png_uint_32     vpAg_width, vpAg_height;
+   png_byte        vpAg_units;
+   png_byte        sTER_mode;
+   int             location[2];
+}
+user_chunk_data;
 
-    /* 0: sTER mode + 1
-     * 1: vpAg width
-     * 2: vpAg height
-     * 3: vpAg units
-     */
+/* Used for location and order; zero means nothing. */
+#define have_sTER   0x01
+#define have_vpAg   0x02
+#define before_PLTE 0x10
+#define before_IDAT 0x20
+#define after_IDAT  0x40
+
+static void
+init_callback_info(png_const_infop info_ptr)
+{
+   MEMZERO(user_chunk_data);
+   user_chunk_data.info_ptr = info_ptr;
+}
+
+static int
+set_location(png_structp png_ptr, struct user_chunk_data *data, int what)
+{
+   int location;
+
+   if ((data->location[0] & what) || (data->location[1] & what))
+      return 0; /* already have one of these */
+
+   /* Find where we are (the code below zeros info_ptr to indicate that the
+    * chunks before the first IDAT have been read.)
+    */
+   if (data->info_ptr == NULL) /* after IDAT */
+      location = what | after_IDAT;
+
+   else if (png_get_valid(png_ptr, data->info_ptr, PNG_INFO_PLTE))
+      location = what | before_IDAT;
+
+   else
+      location = what | before_PLTE;
+
+   if (data->location[0] == 0)
+      data->location[0] = location;
+
+   else
+      data->location[1] = location;
+
+   return 1; /* handled */
+}
 
 static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr,
    png_unknown_chunkp chunk)
 {
-   png_uint_32
-     *my_user_chunk_data;
+   struct user_chunk_data *my_user_chunk_data =
+      (struct user_chunk_data*)png_get_user_chunk_ptr(png_ptr);
+
+   if (my_user_chunk_data == NULL)
+      png_error(png_ptr, "lost user chunk pointer");
 
    /* Return one of the following:
     *    return (-n);  chunk had an error
@@ -599,9 +674,14 @@ static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr,
          if (chunk->data[0] != 0 && chunk->data[0] != 1)
             return (-1);  /* Invalid mode */
 
-         my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr);
-         my_user_chunk_data[0]=chunk->data[0]+1;
-         return (1);
+         if (set_location(png_ptr, my_user_chunk_data, have_sTER))
+         {
+            my_user_chunk_data->sTER_mode=chunk->data[0];
+            return (1);
+         }
+
+         else
+            return (0); /* duplicate sTER - give it to libpng */
       }
 
    if (chunk->name[0] != 118 || chunk->name[1] != 112 ||    /* v  p */
@@ -613,24 +693,119 @@ static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr,
    if (chunk->size != 9)
       return (-1); /* Error return */
 
-   my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr);
+   if (!set_location(png_ptr, my_user_chunk_data, have_vpAg))
+      return (0);  /* duplicate vpAg */
 
-   my_user_chunk_data[1]=png_get_uint_31(png_ptr, chunk->data);
-   my_user_chunk_data[2]=png_get_uint_31(png_ptr, chunk->data + 4);
-   my_user_chunk_data[3]=(png_uint_32)chunk->data[8];
+   my_user_chunk_data->vpAg_width = png_get_uint_31(png_ptr, chunk->data);
+   my_user_chunk_data->vpAg_height = png_get_uint_31(png_ptr, chunk->data + 4);
+   my_user_chunk_data->vpAg_units = chunk->data[8];
 
    return (1);
-
 }
+
+#ifdef PNG_WRITE_SUPPORTED
+static void
+write_sTER_chunk(png_structp write_ptr)
+{
+   png_byte png_sTER[5] = {115,  84,  69,  82, '\0'};
+
+   if (verbose)
+      fprintf(STDERR, "\n stereo mode = %d\n", user_chunk_data.sTER_mode);
+
+   png_write_chunk(write_ptr, png_sTER, &user_chunk_data.sTER_mode, 1);
+}
+
+static void
+write_vpAg_chunk(png_structp write_ptr)
+{
+   png_byte png_vpAg[5] = {118, 112,  65, 103, '\0'};
+
+   png_byte vpag_chunk_data[9];
+
+   if (verbose)
+      fprintf(STDERR, " vpAg = %lu x %lu, units = %d\n",
+        (unsigned long)user_chunk_data.vpAg_width,
+        (unsigned long)user_chunk_data.vpAg_height,
+        user_chunk_data.vpAg_units);
+
+   png_save_uint_32(vpag_chunk_data, user_chunk_data.vpAg_width);
+   png_save_uint_32(vpag_chunk_data + 4, user_chunk_data.vpAg_height);
+   vpag_chunk_data[8] = user_chunk_data.vpAg_units;
+   png_write_chunk(write_ptr, png_vpAg, vpag_chunk_data, 9);
+}
+
+static void
+write_chunks(png_structp write_ptr, int location)
+{
+   int i;
+
+   /* Notice that this preserves the original chunk order, however chunks
+    * intercepted by the callback will be written *after* chunks passed to
+    * libpng.  This will actually reverse a pair of sTER chunks or a pair of
+    * vpAg chunks, resulting in an error later.  This is not worth worrying
+    * about - the chunks should not be duplicated!
+    */
+   for (i=0; i<2; ++i)
+   {
+      if (user_chunk_data.location[i] == (location | have_sTER))
+         write_sTER_chunk(write_ptr);
+
+      else if (user_chunk_data.location[i] == (location | have_vpAg))
+         write_vpAg_chunk(write_ptr);
+   }
+}
+#endif /* PNG_WRITE_SUPPORTED */
+#else /* !PNG_READ_USER_CHUNKS_SUPPORTED */
+#  define write_chunks(pp,loc) ((void)0)
 #endif
 /* END of code to demonstrate user chunk support */
 
+/* START of code to check that libpng has the required text support; this only
+ * checks for the write support because if read support is missing the chunk
+ * will simply not be reported back to pngtest.
+ */
+#ifdef PNG_TEXT_SUPPORTED
+static void
+pngtest_check_text_support(png_const_structp png_ptr, png_textp text_ptr,
+   int num_text)
+{
+   while (num_text > 0)
+   {
+      switch (text_ptr[--num_text].compression)
+      {
+         case PNG_TEXT_COMPRESSION_NONE:
+            break;
+
+         case PNG_TEXT_COMPRESSION_zTXt:
+#           ifndef PNG_WRITE_zTXt_SUPPORTED
+               ++unsupported_chunks;
+#           endif
+            break;
+
+         case PNG_ITXT_COMPRESSION_NONE:
+         case PNG_ITXT_COMPRESSION_zTXt:
+#           ifndef PNG_WRITE_iTXt_SUPPORTED
+               ++unsupported_chunks;
+#           endif
+            break;
+
+         default:
+            /* This is an error */
+            png_error(png_ptr, "invalid text chunk compression field");
+            break;
+      }
+   }
+}
+#endif
+/* END of code to check that libpng has the required text support */
+
 /* Test one file */
 static int
 test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 {
    static png_FILE_p fpin;
    static png_FILE_p fpout;  /* "static" prevents setjmp corruption */
+   pngtest_error_parameters error_parameters;
    png_structp read_ptr;
    png_infop read_info_ptr, end_info_ptr;
 #ifdef PNG_WRITE_SUPPORTED
@@ -648,9 +823,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    int num_pass, pass;
    int bit_depth, color_type;
 
-   char inbuf[256], outbuf[256];
-
    row_buf = NULL;
+   error_parameters.file_name = inname;
 
    if ((fpin = fopen(inname, "rb")) == NULL)
    {
@@ -674,20 +848,9 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    read_ptr =
       png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
-#ifndef PNG_STDIO_SUPPORTED
-   png_set_error_fn(read_ptr, (png_voidp)inname, pngtest_error,
-       pngtest_warning);
-#endif
+   png_set_error_fn(read_ptr, &error_parameters, pngtest_error,
+      pngtest_warning);
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
-   user_chunk_data[0] = 0;
-   user_chunk_data[1] = 0;
-   user_chunk_data[2] = 0;
-   user_chunk_data[3] = 0;
-   png_set_read_user_chunk_fn(read_ptr, user_chunk_data,
-     read_user_chunk_callback);
-
-#endif
 #ifdef PNG_WRITE_SUPPORTED
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
    write_ptr =
@@ -697,10 +860,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    write_ptr =
       png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
-#ifndef PNG_STDIO_SUPPORTED
-   png_set_error_fn(write_ptr, (png_voidp)inname, pngtest_error,
-       pngtest_warning);
-#endif
+   png_set_error_fn(write_ptr, &error_parameters, pngtest_error,
+      pngtest_warning);
 #endif
    pngtest_debug("Allocating read_info, write_info and end_info structures");
    read_info_ptr = png_create_info_struct(read_ptr);
@@ -710,6 +871,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    write_end_info_ptr = png_create_info_struct(write_ptr);
 #endif
 
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   init_callback_info(read_info_ptr);
+   png_set_read_user_chunk_fn(read_ptr, &user_chunk_data,
+     read_user_chunk_callback);
+#endif
+
 #ifdef PNG_SETJMP_SUPPORTED
    pngtest_debug("Setting jmpbuf for read struct");
    if (setjmp(png_jmpbuf(read_ptr)))
@@ -749,11 +916,26 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       /* Treat png_benign_error() as errors on read */
       png_set_benign_errors(read_ptr, 0);
-   
+
+#ifdef PNG_WRITE_SUPPORTED
       /* Treat them as errors on write */
       png_set_benign_errors(write_ptr, 0);
+#endif
 
-      /* if strict is not set, then both are treated as warnings. */
+      /* if strict is not set, then app warnings and errors are treated as
+       * warnings in release builds, but not in unstable builds; this can be
+       * changed with '--relaxed'.
+       */
+   }
+
+   else if (relaxed)
+   {
+      /* Allow application (pngtest) errors and warnings to pass */
+      png_set_benign_errors(read_ptr, 1);
+
+#ifdef PNG_WRITE_SUPPORTED
+      png_set_benign_errors(write_ptr, 1);
+#endif
    }
 
    pngtest_debug("Initializing input and output streams");
@@ -774,14 +956,6 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #  endif
 #endif
 
-#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
-   /* Normally one would use Z_DEFAULT_STRATEGY for text compression.
-    * This is here just to make pngtest replicate the results from libpng
-    * versions prior to 1.5.4, and to test this new API.
-    */
-   png_set_text_compression_strategy(write_ptr, Z_FILTERED);
-#endif
-
    if (status_dots_requested == 1)
    {
 #ifdef PNG_WRITE_SUPPORTED
@@ -813,24 +987,37 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_set_write_user_transform_fn(write_ptr, count_zero_samples);
 #endif
 
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-#  ifndef PNG_HANDLE_CHUNK_ALWAYS
-#    define PNG_HANDLE_CHUNK_ALWAYS       3
-#  endif
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   /* Preserve all the unknown chunks, if possible.  If this is disabled then,
+    * even if the png_{get,set}_unknown_chunks stuff is enabled, we can't use
+    * libpng to *save* the unknown chunks on read (because we can't switch the
+    * save option on!)
+    *
+    * Notice that if SET_UNKNOWN_CHUNKS is *not* supported read will discard all
+    * unknown chunks and write will write them all.
+    */
+#ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
    png_set_keep_unknown_chunks(read_ptr, PNG_HANDLE_CHUNK_ALWAYS,
       NULL, 0);
 #endif
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-#  ifndef PNG_HANDLE_CHUNK_IF_SAFE
-#    define PNG_HANDLE_CHUNK_IF_SAFE      2
-#  endif
-   png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_IF_SAFE,
+   png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_ALWAYS,
       NULL, 0);
+#endif
 #endif
 
    pngtest_debug("Reading info struct");
    png_read_info(read_ptr, read_info_ptr);
 
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   /* This is a bit of a hack; there is no obvious way in the callback function
+    * to determine that the chunks before the first IDAT have been read, so
+    * remove the info_ptr (which is only used to determine position relative to
+    * PLTE) here to indicate that we are after the IDAT.
+    */
+   user_chunk_data.info_ptr = NULL;
+#endif
+
    pngtest_debug("Transferring info struct");
    {
       int interlace_type, compression_type, filter_type;
@@ -1022,6 +1209,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       {
          pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
 
+         pngtest_check_text_support(read_ptr, text_ptr, num_text);
+
          if (verbose)
          {
             int i;
@@ -1047,10 +1236,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          png_set_tIME(write_ptr, write_info_ptr, mod_time);
 #ifdef PNG_TIME_RFC1123_SUPPORTED
          if (png_convert_to_rfc1123_buffer(tIME_string, mod_time))
-            tIME_string[png_sizeof(tIME_string) - 1] = '\0';
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
 
          else
-            strcpy(tIME_string, "*** invalid time ***");
+         {
+            strncpy(tIME_string, "*** invalid time ***", (sizeof tIME_string));
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
+         }
 
          tIME_chunk_present++;
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
@@ -1087,16 +1279,20 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 
       if (num_unknowns)
       {
-         int i;
          png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns,
            num_unknowns);
+#if PNG_LIBPNG_VER < 10600
          /* Copy the locations from the read_info_ptr.  The automatically
-          * generated locations in write_info_ptr are wrong because we
-          * haven't written anything yet.
+          * generated locations in write_end_info_ptr are wrong prior to 1.6.0
+          * because they are reset from the write pointer (removed in 1.6.0).
           */
-         for (i = 0; i < num_unknowns; i++)
-           png_set_unknown_chunk_location(write_ptr, write_info_ptr, i,
-             unknowns[i].location);
+         {
+            int i;
+            for (i = 0; i < num_unknowns; i++)
+              png_set_unknown_chunk_location(write_ptr, write_info_ptr, i,
+                unknowns[i].location);
+         }
+#endif
       }
    }
 #endif
@@ -1104,47 +1300,16 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_WRITE_SUPPORTED
    pngtest_debug("Writing info struct");
 
-/* If we wanted, we could write info in two steps:
- * png_write_info_before_PLTE(write_ptr, write_info_ptr);
- */
+   /* Write the info in two steps so that if we write the 'unknown' chunks here
+    * they go to the correct place.
+    */
+   png_write_info_before_PLTE(write_ptr, write_info_ptr);
+
+   write_chunks(write_ptr, before_PLTE); /* before PLTE */
+
    png_write_info(write_ptr, write_info_ptr);
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
-   if (user_chunk_data[0] != 0)
-   {
-      png_byte png_sTER[5] = {115,  84,  69,  82, '\0'};
-
-      unsigned char
-        ster_chunk_data[1];
-
-      if (verbose)
-         fprintf(STDERR, "\n stereo mode = %lu\n",
-           (unsigned long)(user_chunk_data[0] - 1));
-
-      ster_chunk_data[0]=(unsigned char)(user_chunk_data[0] - 1);
-      png_write_chunk(write_ptr, png_sTER, ster_chunk_data, 1);
-   }
-
-   if (user_chunk_data[1] != 0 || user_chunk_data[2] != 0)
-   {
-      png_byte png_vpAg[5] = {118, 112,  65, 103, '\0'};
-
-      unsigned char
-        vpag_chunk_data[9];
-
-      if (verbose)
-         fprintf(STDERR, " vpAg = %lu x %lu, units = %lu\n",
-           (unsigned long)user_chunk_data[1],
-           (unsigned long)user_chunk_data[2],
-           (unsigned long)user_chunk_data[3]);
-
-      png_save_uint_32(vpag_chunk_data, user_chunk_data[1]);
-      png_save_uint_32(vpag_chunk_data + 4, user_chunk_data[2]);
-      vpag_chunk_data[8] = (unsigned char)(user_chunk_data[3] & 0xff);
-      png_write_chunk(write_ptr, png_vpAg, vpag_chunk_data, 9);
-   }
-
-#endif
+   write_chunks(write_ptr, before_IDAT); /* after PLTE */
 #endif
 
 #ifdef SINGLE_ROWBUF_ALLOC
@@ -1228,6 +1393,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       {
          pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
 
+         pngtest_check_text_support(read_ptr, text_ptr, num_text);
+
          if (verbose)
          {
             int i;
@@ -1253,10 +1420,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          png_set_tIME(write_ptr, write_end_info_ptr, mod_time);
 #ifdef PNG_TIME_RFC1123_SUPPORTED
          if (png_convert_to_rfc1123_buffer(tIME_string, mod_time))
-            tIME_string[png_sizeof(tIME_string) - 1] = '\0';
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
 
          else
-            strcpy(tIME_string, "*** invalid time ***");
+         {
+            strncpy(tIME_string, "*** invalid time ***", sizeof tIME_string);
+            tIME_string[(sizeof tIME_string)-1] = '\0';
+         }
 
          tIME_chunk_present++;
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
@@ -1271,20 +1441,40 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 
       if (num_unknowns)
       {
-         int i;
          png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns,
            num_unknowns);
+#if PNG_LIBPNG_VER < 10600
          /* Copy the locations from the read_info_ptr.  The automatically
-          * generated locations in write_end_info_ptr are wrong because we
-          * haven't written the end_info yet.
+          * generated locations in write_end_info_ptr are wrong prior to 1.6.0
+          * because they are reset from the write pointer (removed in 1.6.0).
           */
-         for (i = 0; i < num_unknowns; i++)
-           png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i,
-             unknowns[i].location);
+         {
+            int i;
+            for (i = 0; i < num_unknowns; i++)
+              png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i,
+                unknowns[i].location);
+         }
+#endif
       }
    }
 #endif
+
 #ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   /* Normally one would use Z_DEFAULT_STRATEGY for text compression.
+    * This is here just to make pngtest replicate the results from libpng
+    * versions prior to 1.5.4, and to test this new API.
+    */
+   png_set_text_compression_strategy(write_ptr, Z_FILTERED);
+#endif
+
+   /* When the unknown vpAg/sTER chunks are written by pngtest the only way to
+    * do it is to write them *before* calling png_write_end.  When unknown
+    * chunks are written by libpng, however, they are written just before IEND.     * There seems to be no way round this, however vpAg/sTER are not expected
+    * after IDAT.
+    */
+   write_chunks(write_ptr, after_IDAT);
+
    png_write_end(write_ptr, write_end_info_ptr);
 #endif
 
@@ -1318,6 +1508,40 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    FCLOSE(fpin);
    FCLOSE(fpout);
 
+   /* Summarize any warnings or errors and in 'strict' mode fail the test.
+    * Unsupported chunks can result in warnings, in that case ignore the strict
+    * setting, otherwise fail the test on warnings as well as errors.
+    */
+   if (error_count > 0)
+   {
+      /* We don't really expect to get here because of the setjmp handling
+       * above, but this is safe.
+       */
+      fprintf(STDERR, "\n  %s: %d libpng errors found (%d warnings)",
+         inname, error_count, warning_count);
+
+      if (strict != 0)
+         return (1);
+   }
+
+#  ifdef PNG_WRITE_SUPPORTED
+      /* If there we no write support nothing was written! */
+      else if (unsupported_chunks > 0)
+      {
+         fprintf(STDERR, "\n  %s: unsupported chunks (%d)%s",
+            inname, unsupported_chunks, strict ? ": IGNORED --strict!" : "");
+      }
+#  endif
+
+   else if (warning_count > 0)
+   {
+      fprintf(STDERR, "\n  %s: %d libpng warnings found",
+         inname, warning_count);
+
+      if (strict != 0)
+         return (1);
+   }
+
    pngtest_debug("Opening files for comparison");
    if ((fpin = fopen(inname, "rb")) == NULL)
    {
@@ -1332,71 +1556,85 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       return (1);
    }
 
-   for (;;)
+#ifdef PNG_WRITE_SUPPORTED /* else nothing was written */
    {
-      png_size_t num_in, num_out;
+      int wrote_question = 0;
 
-         num_in = fread(inbuf, 1, 1, fpin);
-         num_out = fread(outbuf, 1, 1, fpout);
-
-      if (num_in != num_out)
+      for (;;)
       {
-         fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
-                 inname, outname);
+         png_size_t num_in, num_out;
+         char inbuf[256], outbuf[256];
 
-         if (wrote_question == 0)
+
+         num_in = fread(inbuf, 1, sizeof inbuf, fpin);
+         num_out = fread(outbuf, 1, sizeof outbuf, fpout);
+
+         if (num_in != num_out)
          {
-            fprintf(STDERR,
-         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
-              inname, PNG_ZBUF_SIZE);
-            fprintf(STDERR,
-              "\n   filtering heuristic (libpng default), compression");
-            fprintf(STDERR,
-              " level (zlib default),\n   and zlib version (%s)?\n\n",
-              ZLIB_VERSION);
-            wrote_question = 1;
-         }
+            fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
+                    inname, outname);
 
-         FCLOSE(fpin);
-         FCLOSE(fpout);
-
-         if (strict != 0)
-           return (1);
-
-         else
-           return (0);
-      }
-
-      if (!num_in)
-         break;
-
-      if (memcmp(inbuf, outbuf, num_in))
-      {
-         fprintf(STDERR, "\nFiles %s and %s are different\n", inname, outname);
-
-         if (wrote_question == 0)
-         {
-            fprintf(STDERR,
+            if (wrote_question == 0 && unsupported_chunks == 0)
+            {
+               fprintf(STDERR,
          "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
                  inname, PNG_ZBUF_SIZE);
-            fprintf(STDERR,
-              "\n   filtering heuristic (libpng default), compression");
-            fprintf(STDERR,
-              " level (zlib default),\n   and zlib version (%s)?\n\n",
-              ZLIB_VERSION);
-            wrote_question = 1;
+               fprintf(STDERR,
+                 "\n   filtering heuristic (libpng default), compression");
+               fprintf(STDERR,
+                 " level (zlib default),\n   and zlib version (%s)?\n\n",
+                 ZLIB_VERSION);
+               wrote_question = 1;
+            }
+
+            FCLOSE(fpin);
+            FCLOSE(fpout);
+
+            if (strict != 0 && unsupported_chunks == 0)
+              return (1);
+
+            else
+              return (0);
          }
 
-         FCLOSE(fpin);
-         FCLOSE(fpout);
+         if (!num_in)
+            break;
 
-         if (strict != 0)
-           return (1);
+         if (memcmp(inbuf, outbuf, num_in))
+         {
+            fprintf(STDERR, "\nFiles %s and %s are different\n", inname,
+               outname);
 
-         else
-           return (0);
+            if (wrote_question == 0 && unsupported_chunks == 0)
+            {
+               fprintf(STDERR,
+         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+                    inname, PNG_ZBUF_SIZE);
+               fprintf(STDERR,
+                 "\n   filtering heuristic (libpng default), compression");
+               fprintf(STDERR,
+                 " level (zlib default),\n   and zlib version (%s)?\n\n",
+                 ZLIB_VERSION);
+               wrote_question = 1;
+            }
+
+            FCLOSE(fpin);
+            FCLOSE(fpout);
+
+            /* NOTE: the unsupported_chunks escape is permitted here because
+             * unsupported text chunk compression will result in the compression
+             * mode being changed (to NONE) yet, in the test case, the result
+             * can be exactly the same size!
+             */
+            if (strict != 0 && unsupported_chunks == 0)
+              return (1);
+
+            else
+              return (0);
+         }
       }
    }
+#endif /* PNG_WRITE_SUPPORTED */
 
    FCLOSE(fpin);
    FCLOSE(fpout);
@@ -1482,6 +1720,16 @@ main(int argc, char *argv[])
          verbose = 1;
          inname = argv[2];
          strict++;
+         relaxed = 0;
+      }
+
+      else if (strcmp(argv[1], "--relaxed") == 0)
+      {
+         status_dots_requested = 0;
+         verbose = 1;
+         inname = argv[2];
+         strict = 0;
+         relaxed++;
       }
 
       else
@@ -1690,6 +1938,15 @@ main(int argc, char *argv[])
 
    return (int)(ierror != 0);
 }
+#else
+int
+main(void)
+{
+   fprintf(STDERR,
+      " test ignored because libpng was not built with read support\n");
+   return 0;
+}
+#endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_0beta25 Your_png_h_is_not_version_1_6_0beta25;
+typedef png_libpng_version_1_6_0beta35 Your_png_h_is_not_version_1_6_0beta35;

pngtrans.c

@@ -122,32 +122,79 @@ png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
    if (png_ptr == NULL)
       return;
 
+   /* In libpng 1.6 it is possible to determine whether this is a read or write
+    * operation and therefore to do more checking here for a valid call.
+    */
+   if (png_ptr->mode & PNG_IS_READ_STRUCT)
+   {
+#     ifdef PNG_READ_FILLER_SUPPORTED
+         /* On read png_set_filler is always valid, regardless of the base PNG
+          * format, because other transformations can give a format where the
+          * filler code can execute (basically an 8 or 16-bit component RGB or G
+          * format.)
+          *
+          * NOTE: usr_channels is not used by the read code!  (This has led to
+          * confusion in the past.)  The filler is only used in the read code.
+          */
+         png_ptr->filler = (png_uint_16)filler;
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on read");
+         PNG_UNUSED(filler) /* not used in the write case */
+         return;
+#     endif
+   }
+
+   else /* write */
+   {
+#     ifdef PNG_WRITE_FILLER_SUPPORTED
+         /* On write the usr_channels parameter must be set correctly at the
+          * start to record the number of channels in the app-supplied data.
+          */
+         switch (png_ptr->color_type)
+         {
+            case PNG_COLOR_TYPE_RGB:
+               png_ptr->usr_channels = 4;
+               break;
+
+            case PNG_COLOR_TYPE_GRAY:
+               if (png_ptr->bit_depth >= 8)
+               {
+                  png_ptr->usr_channels = 2;
+                  break;
+               }
+
+               else
+               {
+                  /* There simply isn't any code in libpng to strip out bits
+                   * from bytes when the components are less than a byte in
+                   * size!
+                   */
+                  png_app_error(png_ptr,
+                     "png_set_filler is invalid for low bit depth gray output");
+                  return;
+               }
+
+            default:
+               png_app_error(png_ptr,
+                  "png_set_filler: inappropriate color type");
+               return;
+         }
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on write");
+         return;
+#     endif
+   }
+
+   /* Here on success - libpng supports the operation, set the transformation
+    * and the flag to say where the filler channel is.
+    */
    png_ptr->transformations |= PNG_FILLER;
-   png_ptr->filler = (png_uint_16)filler;
 
    if (filler_loc == PNG_FILLER_AFTER)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
 
    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
-
-   /* This should probably go in the "do_read_filler" routine.
-    * I attempted to do that in libpng-1.0.1a but that caused problems
-    * so I restored it in libpng-1.0.2a
-   */
-
-   if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
-   {
-      png_ptr->usr_channels = 4;
-   }
-
-   /* Also I added this in libpng-1.0.2a (what happens when we expand
-    * a less-than-8-bit grayscale to GA?) */
-
-   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
-   {
-      png_ptr->usr_channels = 2;
-   }
 }
 
 /* Added to libpng-1.2.7 */
@@ -160,7 +207,9 @@ png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
       return;
 
    png_set_filler(png_ptr, filler, filler_loc);
-   png_ptr->transformations |= PNG_ADD_ALPHA;
+   /* The above may fail to do anything. */
+   if (png_ptr->transformations & PNG_FILLER)
+      png_ptr->transformations |= PNG_ADD_ALPHA;
 }
 
 #endif

pngwrite.c

@@ -18,6 +18,59 @@
 
 #ifdef PNG_WRITE_SUPPORTED
 
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+/* Write out all the unknown chunks for the current given location */
+static void
+write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
+   unsigned int where)
+{
+   if (info_ptr->unknown_chunks_num)
+   {
+      png_const_unknown_chunkp up;
+
+      png_debug(5, "writing extra chunks");
+
+      for (up = info_ptr->unknown_chunks;
+           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+           ++up)
+         if (up->location & where)
+      {
+         /* If per-chunk unknown chunk handling is enabled use it, otherwise
+          * just write the chunks the application has set.
+          */
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+         int keep = png_handle_as_unknown(png_ptr, up->name);
+
+         /* NOTE: this code is radically different from the read side in the
+          * matter of handling an ancillary unknown chunk.  In the read side
+          * the default behavior is to discard it, in the code below the default
+          * behavior is to write it.  Critical chunks are, however, only
+          * written if explicitly listed or if the default is set to write all
+          * unknown chunks.
+          *
+          * The default handling is also slightly weird - it is not possible to
+          * stop the writing of all unsafe-to-copy chunks!
+          *
+          * TODO: REVIEW: this would seem to be a bug.
+          */
+         if (keep != PNG_HANDLE_CHUNK_NEVER &&
+             ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ ||
+              keep == PNG_HANDLE_CHUNK_ALWAYS ||
+              (keep == PNG_HANDLE_CHUNK_AS_DEFAULT &&
+               png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS)))
+#endif
+         {
+            /* TODO: review, what is wrong with a zero length unknown chunk? */
+            if (up->size == 0)
+               png_warning(png_ptr, "Writing zero-length unknown chunk");
+
+            png_write_chunk(png_ptr, up->name, up->data, up->size);
+         }
+      }
+   }
+}
+#endif /* PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED */
+
 /* Writes all the PNG information.  This is the suggested way to use the
  * library.  If you have a new chunk to add, make a function to write it,
  * and put it in the correct location here.  If you want the chunk written
@@ -54,10 +107,12 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
        info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
        info_ptr->filter_type,
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
-       info_ptr->interlace_type);
+       info_ptr->interlace_type
 #else
-       0);
+       0
 #endif
+      );
+
    /* The rest of these check to see if the valid field has the appropriate
     * flag set, and if it does, writes the chunk.
     *
@@ -125,34 +180,9 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
 #endif
 
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-   if (info_ptr->unknown_chunks_num)
-   {
-      png_unknown_chunk *up;
-
-      png_debug(5, "writing extra chunks");
-
-      for (up = info_ptr->unknown_chunks;
-           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
-           up++)
-      {
-         int keep = png_handle_as_unknown(png_ptr, up->name);
-
-         if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location &&
-             !(up->location & PNG_HAVE_PLTE) &&
-             !(up->location & PNG_HAVE_IDAT) &&
-             !(up->location & PNG_AFTER_IDAT) &&
-             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
-             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
-         {
-            if (up->size == 0)
-               png_warning(png_ptr, "Writing zero-length unknown chunk");
-
-            png_write_chunk(png_ptr, up->name, up->data, up->size);
-         }
-      }
-   }
+      write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR);
 #endif
+
       png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
    }
 }
@@ -302,29 +332,7 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
 #endif /* tEXt */
 
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-   if (info_ptr->unknown_chunks_num)
-   {
-      png_unknown_chunk *up;
-
-      png_debug(5, "writing extra chunks");
-
-      for (up = info_ptr->unknown_chunks;
-           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
-           up++)
-      {
-         int keep = png_handle_as_unknown(png_ptr, up->name);
-         if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location &&
-             (up->location & PNG_HAVE_PLTE) &&
-             !(up->location & PNG_HAVE_IDAT) &&
-             !(up->location & PNG_AFTER_IDAT) &&
-             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
-             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
-         {
-            png_write_chunk(png_ptr, up->name, up->data, up->size);
-         }
-      }
-   }
+   write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE);
 #endif
 }
 
@@ -416,27 +424,7 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
       }
 #endif
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-   if (info_ptr->unknown_chunks_num)
-   {
-      png_unknown_chunk *up;
-
-      png_debug(5, "writing extra chunks");
-
-      for (up = info_ptr->unknown_chunks;
-           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
-           up++)
-      {
-         int keep = png_handle_as_unknown(png_ptr, up->name);
-         if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location &&
-             (up->location & PNG_AFTER_IDAT) &&
-             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
-             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
-         {
-            png_write_chunk(png_ptr, up->name, up->data, up->size);
-         }
-      }
-   }
+      write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
 #endif
    }
 
@@ -459,7 +447,6 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
 }
 
 #ifdef PNG_CONVERT_tIME_SUPPORTED
-/* "tm" structure is not supported on WindowsCE */
 void PNGAPI
 png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime)
 {
@@ -513,15 +500,19 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
     */
    png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
 
-   png_ptr->zlib_strategy = Z_FILTERED; /* may be overridden if no filters */
-   png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
+   /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
+    * pngwutil.c defaults it according to whether or not filters will be used,
+    * and ignores this setting.
+    */
+   png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
+   png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
    png_ptr->zlib_mem_level = 8;
    png_ptr->zlib_window_bits = 15;
    png_ptr->zlib_method = 8;
 
 #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
-   png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;
-   png_ptr->zlib_text_level = Z_DEFAULT_COMPRESSION;
+   png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
+   png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
    png_ptr->zlib_text_mem_level = 8;
    png_ptr->zlib_text_window_bits = 15;
    png_ptr->zlib_text_method = 8;
@@ -762,7 +753,7 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
    png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
 
    /* Copy user's row into buffer, leaving room for filter byte. */
-   png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
+   memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Handle interlacing */
@@ -858,7 +849,7 @@ png_write_flush(png_structrp png_ptr)
 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-static void png_reset_filter_heuristics(png_structrp png_ptr); /* forward decl */
+static void png_reset_filter_heuristics(png_structrp png_ptr);/* forward decl */
 #endif
 
 /* Free any memory used in png_ptr struct without freeing the struct itself. */
@@ -889,7 +880,7 @@ png_write_destroy(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->inv_filter_costs);
 #endif
 
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
    png_free(png_ptr, png_ptr->chunk_list);
 #endif
 
@@ -948,7 +939,8 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
 #ifdef PNG_WRITE_FILTER_SUPPORTED
          case 5:
          case 6:
-         case 7: png_warning(png_ptr, "Unknown row filter for method 0");
+         case 7: png_app_error(png_ptr, "Unknown row filter for method 0");
+            /* FALL THROUGH */
 #endif /* PNG_WRITE_FILTER_SUPPORTED */
          case PNG_FILTER_VALUE_NONE:
             png_ptr->do_filter = PNG_FILTER_NONE; break;
@@ -970,7 +962,7 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
             png_ptr->do_filter = (png_byte)filters; break;
 #else
          default:
-            png_warning(png_ptr, "Unknown row filter for method 0");
+            png_app_error(png_ptr, "Unknown row filter for method 0");
 #endif /* PNG_WRITE_FILTER_SUPPORTED */
       }
 
@@ -1116,7 +1108,7 @@ png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method,
       if (num_weights > 0)
       {
          png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_byte) * num_weights));
+             (png_uint_32)((sizeof (png_byte)) * num_weights));
 
          /* To make sure that the weighting starts out fairly */
          for (i = 0; i < num_weights; i++)
@@ -1125,10 +1117,10 @@ png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method,
          }
 
          png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+             (png_uint_32)((sizeof (png_uint_16)) * num_weights));
 
          png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+             (png_uint_32)((sizeof (png_uint_16)) * num_weights));
 
          for (i = 0; i < num_weights; i++)
          {
@@ -1146,10 +1138,10 @@ png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method,
       if (png_ptr->filter_costs == NULL)
       {
          png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+             (png_uint_32)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST));
 
          png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+             (png_uint_32)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST));
       }
 
       for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
@@ -1347,7 +1339,7 @@ png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
    /* Prior to 1.6.0 this would warn but then set the window_bits value, this
     * meant that negative window bits values could be selected which would cause
     * libpng to write a non-standard PNG file with raw deflate or gzip
-    * compressed IDAT or ancilliary chunks.  Such files can be read and there is
+    * compressed IDAT or ancillary chunks.  Such files can be read and there is
     * no warning on read, so this seems like a very bad idea.
     */
    if (window_bits > 15)
@@ -1586,11 +1578,11 @@ png_image_write_init(png_imagep image)
       if (info_ptr != NULL)
       {
          png_controlp control = png_voidcast(png_controlp,
-            png_malloc_warn(png_ptr, sizeof *control));
+            png_malloc_warn(png_ptr, (sizeof *control)));
 
          if (control != NULL)
          {
-            png_memset(control, 0, sizeof *control);
+            memset(control, 0, (sizeof *control));
 
             control->png_ptr = png_ptr;
             control->info_ptr = info_ptr;
@@ -1607,7 +1599,7 @@ png_image_write_init(png_imagep image)
       png_destroy_write_struct(&png_ptr, NULL);
    }
 
-   return png_image_error(image, "png_image_read: out of memory");
+   return png_image_error(image, "png_image_write_: out of memory");
 }
 
 /* Arguments to png_image_write_main: */
@@ -1907,8 +1899,8 @@ png_image_set_PLTE(png_image_write_control *display)
    png_color palette[256];
    png_byte tRNS[256];
 
-   memset(tRNS, 255, sizeof tRNS);
-   memset(palette, 0, sizeof palette);
+   memset(tRNS, 255, (sizeof tRNS));
+   memset(palette, 0, (sizeof palette));
 
    for (i=num_trans=0; i<entries; ++i)
    {
@@ -2154,7 +2146,7 @@ png_image_write_main(png_voidp argument)
       ptrdiff_t row_bytes = display->row_stride;
 
       if (linear)
-         row_bytes *= sizeof (png_uint_16);
+         row_bytes *= (sizeof (png_uint_16));
 
       if (row_bytes < 0)
          row += (image->height-1) * (-row_bytes);
@@ -2224,7 +2216,7 @@ png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
    const void *buffer, png_int_32 row_stride, const void *colormap)
 {
    /* Write the image to the given (FILE*). */
-   if (image != NULL || image->version != PNG_IMAGE_VERSION)
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
    {
       if (file != NULL)
       {
@@ -2239,7 +2231,7 @@ png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
              */
             image->opaque->png_ptr->io_ptr = file;
 
-            png_memset(&display, 0, sizeof display);
+            memset(&display, 0, (sizeof display));
             display.image = image;
             display.buffer = buffer;
             display.row_stride = row_stride;
@@ -2260,6 +2252,10 @@ png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
             "png_image_write_to_stdio: invalid argument");
    }
 
+   else if (image != NULL)
+      return png_image_error(image,
+         "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
+
    else
       return 0;
 }
@@ -2270,7 +2266,7 @@ png_image_write_to_file(png_imagep image, const char *file_name,
    const void *colormap)
 {
    /* Write the image to the named file. */
-   if (image != NULL || image->version != PNG_IMAGE_VERSION)
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
    {
       if (file_name != NULL)
       {
@@ -2323,6 +2319,10 @@ png_image_write_to_file(png_imagep image, const char *file_name,
             "png_image_write_to_file: invalid argument");
    }
 
+   else if (image != NULL)
+      return png_image_error(image,
+         "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
+
    else
       return 0;
 }

pngwutil.c

@@ -29,23 +29,6 @@ png_save_uint_32(png_bytep buf, png_uint_32 i)
    buf[3] = (png_byte)(i & 0xff);
 }
 
-#ifdef PNG_SAVE_INT_32_SUPPORTED
-/* The png_save_int_32 function assumes integers are stored in two's
- * complement format.  If this isn't the case, then this routine needs to
- * be modified to write data in two's complement format.  Note that,
- * the following works correctly even if png_int_32 has more than 32 bits
- * (compare the more complex code required on read for sign extention.)
- */
-void PNGAPI
-png_save_int_32(png_bytep buf, png_int_32 i)
-{
-   buf[0] = (png_byte)((i >> 24) & 0xff);
-   buf[1] = (png_byte)((i >> 16) & 0xff);
-   buf[2] = (png_byte)((i >> 8) & 0xff);
-   buf[3] = (png_byte)(i & 0xff);
-}
-#endif
-
 /* Place a 16-bit number into a buffer in PNG byte order.
  * The parameter is declared unsigned int, not png_uint_16,
  * just to avoid potential problems on pre-ANSI C compilers.
@@ -235,18 +218,18 @@ png_image_size(png_structrp png_ptr)
           */
          png_uint_32 w = png_ptr->width;
          unsigned int pd = png_ptr->pixel_depth;
-         png_alloc_size_t cbBase;
+         png_alloc_size_t cb_base;
          int pass;
 
-         for (cbBase=0, pass=0; pass<=6; ++pass)
+         for (cb_base=0, pass=0; pass<=6; ++pass)
          {
             png_uint_32 pw = PNG_PASS_COLS(w, pass);
 
             if (pw > 0)
-               cbBase += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
+               cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
          }
 
-         return cbBase;
+         return cb_base;
       }
 
       else
@@ -324,7 +307,7 @@ png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
        * internal error, but is very useful for debugging.  i18n requirements
        * are minimal.
        */
-      (void)png_safecat(msg, sizeof msg, 10, " using zstream");
+      (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
 #     if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
          png_warning(png_ptr, msg);
 
@@ -355,10 +338,10 @@ png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
             strategy = png_ptr->zlib_strategy;
 
          else if (png_ptr->do_filter != PNG_FILTER_NONE)
-            strategy = Z_FILTERED;
+            strategy = PNG_Z_DEFAULT_STRATEGY;
 
          else
-            strategy = Z_DEFAULT_STRATEGY;
+            strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;
       }
 
       else
@@ -452,6 +435,27 @@ png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
    }
 }
 
+/* Clean up (or trim) a linked list of compression buffers. */
+void /* PRIVATE */
+png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
+{
+   png_compression_bufferp list = *listp;
+
+   if (list != NULL)
+   {
+      *listp = NULL;
+
+      do
+      {
+         png_compression_bufferp next = list->next;
+
+         png_free(png_ptr, list);
+         list = next;
+      }
+      while (list != NULL);
+   }
+}
+
 #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
 /* This pair of functions encapsulates the operation of (a) compressing a
  * text string, and (b) issuing it later as a series of chunk data writes.
@@ -480,26 +484,6 @@ png_text_compress_init(compression_state *comp, png_const_bytep input,
    comp->output_len = 0;
 }
 
-void /* PRIVATE */
-png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
-{
-   png_compression_bufferp list = *listp;
-
-   if (list != NULL)
-   {
-      *listp = NULL;
-
-      do
-      {
-         png_compression_bufferp next = list->next;
-
-         png_free(png_ptr, list);
-         list = next;
-      }
-      while (list != NULL);
-   }
-}
-
 /* Compress the data in the compression state input */
 static int
 png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
@@ -537,7 +521,7 @@ png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
       png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
       png_ptr->zstream.avail_in = 0; /* Set below */
       png_ptr->zstream.next_out = comp->output;
-      png_ptr->zstream.avail_out = sizeof comp->output;
+      png_ptr->zstream.avail_out = (sizeof comp->output);
 
       output_len = png_ptr->zstream.avail_out;
 
@@ -654,7 +638,7 @@ png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
 {
    png_uint_32 output_len = comp->output_len;
    png_const_bytep output = comp->output;
-   png_uint_32 avail = sizeof comp->output;
+   png_uint_32 avail = (sizeof comp->output);
    png_compression_buffer *next = png_ptr->zbuffer_list;
 
    for (;;)
@@ -676,7 +660,7 @@ png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
 
    /* This is an internal error; 'next' must have been NULL! */
    if (output_len > 0)
-      png_error(png_ptr, "error writing ancilliary chunked compressed data");
+      png_error(png_ptr, "error writing ancillary chunked compressed data");
 }
 #endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
 
@@ -707,7 +691,7 @@ png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
       *new_key = 0;
       return 0;
    }
-   
+
    while (*key && key_len < 79)
    {
       png_byte ch = (png_byte)(0xff & *key++);
@@ -1025,6 +1009,8 @@ png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
    {
       /* First time.   Ensure we have a temporary buffer for compression and
        * trim the buffer list if it has more than one entry to free memory.
+       * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
+       * created at this point, but the check here is quick and safe.
        */
       if (png_ptr->zbuffer_list == NULL)
       {
@@ -1441,12 +1427,14 @@ png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
    {
       if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
       {
-         png_warning(png_ptr, "Invalid number of transparent colors specified");
+         png_app_warning(png_ptr,
+             "Invalid number of transparent colors specified");
          return;
       }
 
       /* Write the chunk out as it is */
-      png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans);
+      png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
+         (png_size_t)num_trans);
    }
 
    else if (color_type == PNG_COLOR_TYPE_GRAY)
@@ -1454,7 +1442,7 @@ png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
       /* One 16 bit value */
       if (tran->gray >= (1 << png_ptr->bit_depth))
       {
-         png_warning(png_ptr,
+         png_app_warning(png_ptr,
              "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
 
          return;
@@ -1476,7 +1464,7 @@ png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
       if (buf[0] | buf[2] | buf[4])
 #endif
       {
-         png_warning(png_ptr,
+         png_app_warning(png_ptr,
            "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
          return;
       }
@@ -1486,7 +1474,7 @@ png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
 
    else
    {
-      png_warning(png_ptr, "Can't write tRNS with an alpha channel");
+      png_app_warning(png_ptr, "Can't write tRNS with an alpha channel");
    }
 }
 #endif
@@ -1604,7 +1592,7 @@ png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
       text_len = 0;
 
    else
-      text_len = png_strlen(text);
+      text_len = strlen(text);
 
    if (text_len > PNG_UINT_31_MAX - (key_len+1))
       png_error(png_ptr, "tEXt: text too long");
@@ -1638,7 +1626,7 @@ png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
    compression_state comp;
 
    png_debug(1, "in png_write_zTXt");
-   PNG_UNUSED(text_len); /* Always use strlen */
+   PNG_UNUSED(text_len) /* Always use strlen */
 
    if (compression == PNG_TEXT_COMPRESSION_NONE)
    {
@@ -1693,7 +1681,7 @@ png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
    png_debug(1, "in png_write_iTXt");
 
    key_len = png_check_keyword(png_ptr, key, new_key);
-   
+
    if (key_len == 0)
       png_error(png_ptr, "iTXt: invalid keyword");
 
@@ -1819,23 +1807,23 @@ png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
 
    if (purpose_len == 0)
       png_error(png_ptr, "pCAL: invalid keyword");
-   
+
    ++purpose_len; /* terminator */
 
    png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
-   units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
+   units_len = strlen(units) + (nparams == 0 ? 0 : 1);
    png_debug1(3, "pCAL units length = %d", (int)units_len);
    total_len = purpose_len + units_len + 10;
 
    params_len = (png_size_tp)png_malloc(png_ptr,
-       (png_alloc_size_t)(nparams * png_sizeof(png_size_t)));
+       (png_alloc_size_t)(nparams * (sizeof (png_size_t))));
 
    /* Find the length of each parameter, making sure we don't count the
     * null terminator for the last parameter.
     */
    for (i = 0; i < nparams; i++)
    {
-      params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
+      params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
       png_debug2(3, "pCAL parameter %d length = %lu", i,
           (unsigned long)params_len[i]);
       total_len += params_len[i];
@@ -1872,8 +1860,8 @@ png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
 
    png_debug(1, "in png_write_sCAL_s");
 
-   wlen = png_strlen(width);
-   hlen = png_strlen(height);
+   wlen = strlen(width);
+   hlen = strlen(height);
    total_len = wlen + hlen + 2;
 
    if (total_len > 64)
@@ -1883,8 +1871,8 @@ png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
    }
 
    buf[0] = (png_byte)unit;
-   png_memcpy(buf + 1, width, wlen + 1);      /* Append the '\0' here */
-   png_memcpy(buf + wlen + 2, height, hlen);  /* Do NOT append the '\0' here */
+   memcpy(buf + 1, width, wlen + 1);      /* Append the '\0' here */
+   memcpy(buf + wlen + 2, height, hlen);  /* Do NOT append the '\0' here */
 
    png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
    png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
@@ -2119,7 +2107,7 @@ png_write_finish_row(png_structrp png_ptr)
       if (png_ptr->pass < 7)
       {
          if (png_ptr->prev_row != NULL)
-            png_memset(png_ptr->prev_row, 0,
+            memset(png_ptr->prev_row, 0,
                 (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
                 png_ptr->usr_bit_depth, png_ptr->width)) + 1);
 
@@ -2294,7 +2282,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
 
                /* Move the pixel */
                if (dp != sp)
-                  png_memcpy(dp, sp, pixel_bytes);
+                  memcpy(dp, sp, pixel_bytes);
 
                /* Next pixel */
                dp += pixel_bytes;

projects/vstudio/WARNING

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

projects/vstudio/libpng/libpng.vcxproj

@@ -23,8 +23,8 @@
     <Keyword>Win32Proj</Keyword>
     <RootNamespace>libpng</RootNamespace>
   </PropertyGroup>
-  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
     <CharacterSet>MultiByte</CharacterSet>
@@ -101,6 +101,7 @@
       <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
       <Optimization>Disabled</Optimization>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
       <SubSystem>Windows</SubSystem>

projects/vstudio/pnglibconf/pnglibconf.vcxproj

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

projects/vstudio/pngstest/pngstest.vcxproj

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

projects/vstudio/pngtest/pngtest.vcxproj

@@ -23,8 +23,8 @@
     <Keyword>Win32Proj</Keyword>
     <RootNamespace>pngtest</RootNamespace>
   </PropertyGroup>
-  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <CharacterSet>Unicode</CharacterSet>
@@ -91,6 +91,7 @@
       <FunctionLevelLinking>false</FunctionLevelLinking>
       <BrowseInformation>true</BrowseInformation>
       <FloatingPointExceptions>false</FloatingPointExceptions>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>

projects/vstudio/pngunknown/pngunknown.vcxproj

@@ -0,0 +1,219 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug Library|Win32">
+      <Configuration>Debug Library</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release Library|Win32">
+      <Configuration>Release Library</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{C5D3156C-8C8C-4936-B35F-2B829BA36FEC}</ProjectGuid>
+    <Keyword>Win32Proj</Keyword>
+    <RootNamespace>pngunknown</RootNamespace>
+  </PropertyGroup>
+  <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" />
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <LinkIncremental>false</LinkIncremental>
+    <CustomBuildAfterTargets />
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
+    <LinkIncremental>false</LinkIncremental>
+    <CustomBuildAfterTargets />
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <LinkIncremental>false</LinkIncremental>
+    <CustomBuildAfterTargets />
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
+    <LinkIncremental>false</LinkIncremental>
+    <CustomBuildAfterTargets />
+  </PropertyGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <MinimalRebuild>false</MinimalRebuild>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Disabled</Optimization>
+      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <CompileAsManaged>false</CompileAsManaged>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <StringPooling>true</StringPooling>
+      <FunctionLevelLinking>false</FunctionLevelLinking>
+      <BrowseInformation>true</BrowseInformation>
+      <FloatingPointExceptions>false</FloatingPointExceptions>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalDependencies>libpng16.lib</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
+    </Link>
+    <CustomBuildStep>
+      <Message>Executing PNG validation program</Message>
+      <Command>"$(OutDir)pngunknown.exe" --strict --default --touch "$(IntDir)pngunknown.out" ../../../pngtest.png</Command>
+      <Outputs>$(IntDir)pngunknown.out</Outputs>
+      <Inputs>$(OutDir)pngunknown.exe</Inputs>
+    </CustomBuildStep>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <MinimalRebuild>false</MinimalRebuild>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Disabled</Optimization>
+      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <CompileAsManaged>false</CompileAsManaged>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <StringPooling>true</StringPooling>
+      <FunctionLevelLinking>false</FunctionLevelLinking>
+      <BrowseInformation>true</BrowseInformation>
+      <FloatingPointExceptions>false</FloatingPointExceptions>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
+    </Link>
+    <CustomBuildStep>
+      <Message>Executing PNG validation program</Message>
+      <Command>"$(OutDir)pngunknown.exe" --strict --default --touch "$(IntDir)pngunknown.out" ../../../pngtest.png</Command>
+      <Outputs>$(IntDir)pngunknown.out</Outputs>
+      <Inputs>$(OutDir)pngunknown.exe</Inputs>
+    </CustomBuildStep>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Full</Optimization>
+      <FunctionLevelLinking>false</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <CompileAsManaged>false</CompileAsManaged>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <StringPooling>true</StringPooling>
+      <MinimalRebuild>false</MinimalRebuild>
+      <BrowseInformation>true</BrowseInformation>
+      <WholeProgramOptimization>true</WholeProgramOptimization>
+      <FloatingPointExceptions>false</FloatingPointExceptions>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalDependencies>libpng16.lib</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
+    </Link>
+    <CustomBuildStep>
+      <Message>Executing PNG validation program</Message>
+      <Command>"$(OutDir)pngunknown.exe" --strict --default --touch "$(IntDir)pngunknown.out" ../../../pngtest.png</Command>
+      <Outputs>$(IntDir)pngunknown.out</Outputs>
+      <Inputs>$(OutDir)pngunknown.exe</Inputs>
+    </CustomBuildStep>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Full</Optimization>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <FunctionLevelLinking>false</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <CompileAsManaged>false</CompileAsManaged>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <StringPooling>true</StringPooling>
+      <MinimalRebuild>false</MinimalRebuild>
+      <BrowseInformation>true</BrowseInformation>
+      <WholeProgramOptimization>true</WholeProgramOptimization>
+      <FloatingPointExceptions>false</FloatingPointExceptions>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalDependencies>libpng16.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
+    </Link>
+    <CustomBuildStep>
+      <Message>Executing PNG validation program</Message>
+      <Command>"$(OutDir)pngunknown.exe" --strict --default --touch "$(IntDir)pngunknown.out" ../../../pngtest.png</Command>
+      <Outputs>$(IntDir)pngunknown.out</Outputs>
+      <Inputs>$(OutDir)pngunknown.exe</Inputs>
+    </CustomBuildStep>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\..\contrib\libtests\pngunknown.c" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>

projects/vstudio/pngvalid/pngvalid.vcxproj

@@ -23,8 +23,8 @@
     <Keyword>Win32Proj</Keyword>
     <RootNamespace>pngvalid</RootNamespace>
   </PropertyGroup>
-  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <Import Project="$(SolutionDir)\zlib.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <CharacterSet>Unicode</CharacterSet>
@@ -91,6 +91,7 @@
       <FunctionLevelLinking>false</FunctionLevelLinking>
       <BrowseInformation>true</BrowseInformation>
       <FloatingPointExceptions>false</FloatingPointExceptions>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>

projects/vstudio/readme.txt

@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.6.0beta25 - June 16, 2012
+libpng version 1.6.0beta35 - December 22, 2012
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 
@@ -33,8 +33,8 @@ optimization level (e.g. /Od.)
 Linking your application
 ========================
 Normally you should link against the 'release' configuration.  This builds a
-DLL for libpng 1.5 with the default runtime options used by Visual Studio
-2010.  In particular the runtime library is the "MultiThreaded DLL" version.
+DLL for libpng with the default runtime options used by Visual Studio 2010.
+In particular the runtime library is the "MultiThreaded DLL" version.
 If you use Visual Studio defaults to build your application you will have no
 problems.
 
@@ -58,7 +58,8 @@ Debug versions have limited support
 This solution includes limited support for debug versions of libpng.  You
 do not need these unless your own solution itself uses debug builds (it is
 far more effective to debug on the release builds, there is no point building
-a special debug build.)
+a special debug build unless you have heap corruption problems that you can't
+track down.)
 
 The debug build of libpng is minimally supported.  Support for debug builds of
 zlib is also minimal.  You really don't want to do this.

projects/vstudio/vstudio.sln

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

projects/vstudio/zlib.props

@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.6.0beta25 - June 16, 2012
+ * libpng version 1.6.0beta35 - December 22, 2012
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *
@@ -33,5 +33,13 @@
 	 below:
      -->
     <ZLibSrcDir>..\..\..\..\zlib-1.2.5</ZLibSrcDir>
+
+    <!-- The following line allows compilation for an ARM target with Visual
+         Studio 2012.  Notice that this is not supported by the Visual Studio
+         2012 IDE and that the programs that result cannot be run unless they
+         signed by Microsoft.  This is therefore untested; only Microsoft can
+         test it:
+     -->
+    <WindowsSDKDesktopARMSupport>true</WindowsSDKDesktopARMSupport>
   </PropertyGroup>
 </Project>

projects/vstudio/zlib/zlib.vcxproj

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

scripts/README.txt

@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.6.0beta25 - June 16, 2012
+Makefiles for  libpng version 1.6.0beta35 - December 22, 2012
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng16.so.16.1.6.0beta25)
+                       (gcc, creates libpng16.so.16.1.6.0beta35)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -20,7 +20,7 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.dec      =>  DEC Alpha UNIX makefile
  makefile.dj2      =>  DJGPP 2 makefile
  makefile.elf      =>  Linux/ELF makefile symbol versioning,
-                       (gcc, creates libpng16.so.16.1.6.0beta25)
+                       (gcc, creates libpng16.so.16.1.6.0beta35)
  makefile.freebsd  =>  FreeBSD makefile
  makefile.gcc      =>  Generic gcc makefile
  makefile.hpgcc    =>  HPUX makefile using gcc
@@ -35,12 +35,12 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
  makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
  makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng16.so.16.1.6.0beta25)
+                       creates libpng16.so.16.1.6.0beta35)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng16.so.16.1.6.0beta25)
+                       creates libpng16.so.16.1.6.0beta35)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng16.so.16.1.6.0beta25)
+                       creates libpng16.so.16.1.6.0beta35)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile

scripts/def.dfn

@@ -25,7 +25,7 @@ S-OS2 DESCRIPTION "PNG image compression library"-E
 S-OS2 CODE PRELOAD MOVEABLE DISCARDABLE-E
 S--E
 S-EXPORTS-E
-S-;Version 1.5.0beta58-E
+S-;Version 1.6.0beta35-E
 
 /* NOTE: PNG_JOIN is interpreted by the calling script as a signal to
  * join the two things on either side, so we can do symbol

scripts/libpng-config-head.in

@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.6.0beta25
+version=1.6.0beta35
 prefix=""
 libdir=""
 libs=""

scripts/libpng.pc.in

@@ -5,6 +5,6 @@ includedir=@includedir@/libpng16
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.6.0beta25
+Version: 1.6.0beta35
 Libs: -L${libdir} -lpng16
 Cflags: -I${includedir}

scripts/makefile.linux

@@ -236,4 +236,4 @@ pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h
 pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h             pnginfo.h pngdebug.h
 pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h             pnginfo.h pngdebug.h
 
-pngtest.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h pnglibconf.h

scripts/makefile.msys

@@ -0,0 +1,204 @@
+# makefile for libpng using MSYS/gcc (shared, static library)
+# Copyright (C) 2012 Glenn Randers-Pehrson and Christopher M. Wheeler
+#
+# Portions taken from makefile.linux:
+# Copyright (C) 1998, 1999, 2002, 2006, 2008, 2010-2011 Greg Roelofs and
+# Glenn Randers-Pehrson
+# Copyright (C) 2000 Cosmin Truta
+# Copyright (C) 1996, 1997 Andreas Dilger
+# Copyright (C) 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
+# # # # # # # # # # # # # # # # #
+prefix=/usr/local
+exec_prefix=$(prefix)
+
+# Library name:
+LIBNAME = libpng16
+PNGMAJ = 16
+RELEASE = 0
+
+# Shared library names:
+LIBSO=$(LIBNAME).dll
+LIBSOMAJ=$(LIBNAME).dll.$(PNGMAJ)
+LIBSOREL=$(PNGMAJ).$(RELEASE)
+OLDSO=libpng.dll
+
+# Where the zlib library and include files are located.
+#ZLIBLIB=../zlib
+#ZLIBINC=../zlib
+ZLIBLIB=/usr/local/lib
+ZLIBINC=/usr/local/include
+
+# Compiler, linker, lib and other tools
+CC = gcc
+LD = $(CC)
+AR_RC = ar rcs
+RANLIB = ranlib
+RM_F = rm -rf
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+
+#ARCH = -march=pentium3
+#ARCH = -march=i686
+ARCH = 
+CDEBUG = -g -DPNG_DEBUG=5
+LDDEBUG =
+CRELEASE = -O2
+LDRELEASE = -s
+#CFLAGS = -W -Wall $(CDEBUG)
+CFLAGS = -W -Wall $(CRELEASE) $(ARCH)
+#LDFLAGS = $(LDDEBUG)
+LDFLAGS = $(LDRELEASE)
+LIBS = -lz -lm
+
+# File extensions
+O=.o
+A=.a
+EXE=.exe
+
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+
+DESTDIR=
+
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+
+# Variables
+OBJS =  png$(O) pngerror$(O) pngget$(O) pngmem$(O) pngpread$(O) \
+	pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) pngset$(O) \
+	pngtrans$(O) pngwio$(O) pngwrite$(O) pngwtran$(O) pngwutil$(O)
+
+# Targets
+all: static shared
+
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+	cp scripts/pnglibconf.h.prebuilt $@
+
+.c$(O):
+	$(CC) -c $(CFLAGS) -I$(ZLIBINC) $<
+
+static: libpng$(A) pngtest$(EXE)
+
+shared: $(LIBSOMAJ)
+	$(CC) -shared -Wl,-soname,$(LIBSOMAJ) -o $(LIBSO)
+
+$(LIBSO): $(LIBSOMAJ)
+	$(LN_SF) $(LIBSOMAJ) $(LIBSO)
+
+$(LIBSOMAJ):
+	$(CC) -shared -Wl,-soname,$(LIBSOMAJ) -o $(LIBSOMAJ)
+
+libpng$(A): $(OBJS)
+	$(AR_RC) $@ $(OBJS)
+	$(RANLIB) $@
+
+install-headers: png.h pngconf.h pnglibconf.h
+	-@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+	-@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+	cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+	-@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+	-@$(RM_F) $(DI)/libpng
+	(cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+
+install-static: install-headers libpng.a
+	-@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+	cp libpng.a $(DL)/$(LIBNAME).a
+	-@$(RM_F) $(DL)/libpng.a
+	(cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+
+libpng.pc:
+	cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+	-e s!@exec_prefix@!$(exec_prefix)! \
+	-e s!@libdir@!$(LIBPATH)! \
+	-e s!@includedir@!$(INCPATH)! \
+	-e s!-lpng16!-lpng16\ -lz\ -lm! > libpng.pc
+
+libpng-config:
+	( cat scripts/libpng-config-head.in; \
+	echo prefix=\"$(prefix)\"; \
+	echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+	echo L_opts=\"-L$(LIBPATH)\"; \
+	echo R_opts=\"-Wl,-rpath,$(LIBPATH)\"; \
+	echo libs=\"-lpng16 -lz -lm\"; \
+	cat scripts/libpng-config-body.in ) > libpng-config
+
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+	-@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+	-@$(RM_F) $(DL)/$(LIBSO)
+	-@$(RM_F) $(DL)/$(OLDSO)
+	cp $(LIBSO) $(DL)/$(LIBSOREL)
+	(cd $(DL); \
+	$(LN_SF) $(LIBSOREL) $(LIBSO); \
+	$(LN_SF) $(LIBSO) $(OLDSO))
+
+	-@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+	-@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+	-@$(RM_F) $(DL)/pkgconfig/libpng.pc
+	cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+	(cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+
+install-man: libpng.3 libpngpf.3 png.5
+	-@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+	-@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+	-@$(RM_F) $(DM)/man3/libpng.3
+	-@$(RM_F) $(DM)/man3/libpngpf.3
+	cp libpng.3 $(DM)/man3
+	cp libpngpf.3 $(DM)/man3
+	-@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+	-@$(RM_F) $(DM)/man5/png.5
+	cp png.5 $(DM)/man5
+
+install-config: libpng-config
+	-@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+	-@$(RM_F) $(DB)/libpng-config
+	-@$(RM_F) $(DB)/$(LIBNAME)-config
+	cp libpng-config $(DB)/$(LIBNAME)-config
+	(cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+
+install: install-static install-shared install-man install-config
+
+test: pngtest$(EXE)
+	./pngtest$(EXE)
+
+pngtest$(EXE): pngtest$(O) libpng$(A)
+	$(LD) $(LDFLAGS) -L$(ZLIBLIB) -o $@ pngtest$(O) libpng$(A) $(LIBS)
+
+clean:
+	$(RM_F) *$(O) libpng$(A) pngtest$(EXE) pngout.png pnglibconf.h $(LIBSO) \
+	$(LIBSOMAJ) libpng-config
+
+png$(O):      png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread$(O):  png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+
+pngtest$(O):  png.h pngconf.h pnglibconf.h

scripts/makefile.ne12bsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng16
 
 LIB=	png16
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.6.0beta25
+SHLIB_MINOR=	1.6.0beta35
 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=	16
-SHLIB_MINOR=	1.6.0beta25
+SHLIB_MINOR=	1.6.0beta35
 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=	16
-SHLIB_MINOR=	1.6.0beta25
+SHLIB_MINOR=	1.6.0beta35
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \

scripts/options.awk

@@ -102,6 +102,7 @@ pre && version == "search" && version_file != FILENAME{
 
 pre && version == "search" && $0 ~ /^ \* libpng version/{
    version = substr($0, 4)
+   gsub(/\./, " PNG_JOIN . PNG_JOIN", version)
    print "version =", version >out
    next
 }

scripts/pnglibconf.dfa

@@ -8,7 +8,7 @@ com pnglibconf.h - library build configuration
 com
 version
 com
-com Copyright (c) 1998-2011 Glenn Randers-Pehrson
+com Copyright (c) 1998-2012 Glenn Randers-Pehrson
 com
 com This code is released under the libpng license.
 com For conditions of distribution and use, see the disclaimer
@@ -147,6 +147,12 @@ logunsupported = 1
 @#  endif
 @#endif
 
+# IN DEVELOPMENT
+# These are currently experimental features; define them if you want (NOTE:
+# experimental options must be disabled before they are defined in this file!)
+
+# NONE
+
 # Note that PNG_USR_CONFIG only has an effect when building
 # pnglibconf.h
 
@@ -176,6 +182,22 @@ setting PREFIX
 
 setting DEFAULT_READ_MACROS default 1
 
+# These settings configure the default compression level (0-9) and 'strategy';
+# strategy is as defined by the implementors of zlib, it describes the input
+# data and modifies the zlib parameters in an attempt to optimize the balance
+# between search and huffman encoding in the zlib algorithms.  The defaults are
+# the zlib.h defaults - the apparently recursive definition does not arise
+# because the name of the setting is prefixed by PNG_
+#
+# The TEXT values are the defaults when writing compressed text (all forms)
+
+setting Z_DEFAULT_COMPRESSION default Z_DEFAULT_COMPRESSION
+setting Z_DEFAULT_STRATEGY default Z_FILTERED
+setting Z_DEFAULT_NOFILTER_STRATEGY default Z_DEFAULT_STRATEGY
+
+setting TEXT_Z_DEFAULT_COMPRESSION default Z_DEFAULT_COMPRESSION
+setting TEXT_Z_DEFAULT_STRATEGY default Z_DEFAULT_STRATEGY
+
 # The alternative is to call functions to read PNG values, if
 # the functions are turned *off* the read macros must always
 # be enabled, so turning this off will actually force the
@@ -319,6 +341,19 @@ option SAFE_LIMITS enables USER_LIMITS disabled
 # See the comments above about how to change options and settings.
 
 # READ options
+#
+# WARNING: in libpng 1.5 maintained configuration compatibility with earlier
+# versions.  In some cases turning off an option turned off other options, in
+# others it was ineffective unless dependent options were also turned off.
+# Libpng 1.6 changes this: in general if you turn off an option that affects
+# APIs it stays off and simply disables APIs that depend on it.
+#
+# As a result if you simply port the libpng 1.5 configuration to libpng 1.6 you
+# will probably see build failures due to missing APIs.  Fixing these failures
+# requires some, perhaps considerable, knowledge of what your libpng using
+# applications are doing, fortunately there is no great reason for you to move
+# to libpng 1.6; the new interfaces in 1.6 will take several years to become
+# popular.
 
 option READ enables READ_INTERLACING
 
@@ -336,27 +371,42 @@ option READ_QUANTIZE requires READ
 option READ_TRANSFORMS requires READ
 = NO_READ_TRANSFORMS READ_TRANSFORMS_NOT_SUPPORTED
 
-option READ_EXPAND requires READ_TRANSFORMS
-option READ_EXPAND_16 requires READ_TRANSFORMS READ_16BIT enables READ_EXPAND
-option READ_SHIFT requires READ_TRANSFORMS
-option READ_PACK requires READ_TRANSFORMS
-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 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
+# Read gamma handling.  Gamma processing is a core part of libpng and many of
+# the capabilities are dependent on libpng performing gamma correction.
+#
+# In libpng 1.6 disabling gamma processing (setting PNG_NO_READ_GAMMA)
+# consistently disables those parts of the API that depend on it.  Prior to
+# 1.6.0 this was not true; the results were unpredictable and varied between
+# releases.
+#
+# If you disable gamma processing and your program no longer compiles you need
+# to ask whether you really need the APIs that are missing.  If you do then you
+# almost certainly need the gamma processing.
+#
+# If you handle gamma issues outside libpng then you do not need the libpng
+# gamma processing; and it is an enormous waste of space.  You just need to
+# remove the use of libpng APIs that depend on it.
+option READ_GAMMA requires READ_TRANSFORMS READ_gAMA
 
-option READ_ALPHA_MODE requires READ_TRANSFORMS enables READ_GAMMA
-option READ_SWAP_ALPHA requires READ_TRANSFORMS
+option READ_ALPHA_MODE requires READ_TRANSFORMS READ_GAMMA
+option READ_BACKGROUND requires READ_TRANSFORMS READ_STRIP_ALPHA READ_GAMMA
+option READ_BGR requires READ_TRANSFORMS
+option READ_EXPAND_16 requires READ_TRANSFORMS READ_16BIT READ_EXPAND
+option READ_EXPAND requires READ_TRANSFORMS
+option READ_FILLER requires READ_TRANSFORMS
+option READ_GRAY_TO_RGB requires READ_TRANSFORMS
 option READ_INVERT_ALPHA requires READ_TRANSFORMS
+option READ_INVERT requires READ_TRANSFORMS
+option READ_PACK requires READ_TRANSFORMS
+option READ_PACKSWAP requires READ_TRANSFORMS
+option READ_RGB_TO_GRAY requires READ_TRANSFORMS READ_GAMMA
+option READ_SCALE_16_TO_8 requires READ_TRANSFORMS
+option READ_SHIFT requires READ_TRANSFORMS
+option READ_STRIP_16_TO_8 requires READ_TRANSFORMS
 option READ_STRIP_ALPHA requires READ_TRANSFORMS
+option READ_SWAP_ALPHA requires READ_TRANSFORMS
+option READ_SWAP requires READ_TRANSFORMS READ_16BIT
 option READ_USER_TRANSFORM requires READ_TRANSFORMS
-option READ_RGB_TO_GRAY requires READ_TRANSFORMS
 
 option PROGRESSIVE_READ requires READ
 option SEQUENTIAL_READ requires READ
@@ -380,11 +430,6 @@ option INCH_CONVERSIONS
 
 option BUILD_GRAYSCALE_PALETTE
 
-# IN DEVELOPMENT
-# These are currently experimental features; define them if you want
-
-# NOTHING HERE
-
 # WRITE options
 
 option WRITE
@@ -635,9 +680,55 @@ chunk zTXt
 
 option READ_OPT_PLTE requires READ_ANCILLARY_CHUNKS
 
-option READ_UNKNOWN_CHUNKS requires READ
-option READ_UNKNOWN_CHUNKS enables UNKNOWN_CHUNKS READ_USER_CHUNKS
-option READ_USER_CHUNKS requires READ enables USER_CHUNKS
+# Unknown chunk handling
+#
+# 'UNKNOWN_CHUNKS' is a global option to disable all unknown chunk handling on
+# read or write; everything else below requires it (directly or indirectly).
+option UNKNOWN_CHUNKS
+
+# There are three main options to control the ability to read and write unknown
+# chunks.  If either read option is turned on then unknown chunks will be read,
+# otherwise they are skipped.  If the write option is turned on unknown chunks
+# set by png_set_unknown_chunks will be written otherwise it is an error to call
+# that API on a write struct.
+option WRITE_UNKNOWN_CHUNKS requires WRITE requires UNKNOWN_CHUNKS
+option WRITE_UNKNOWN_CHUNKS enables STORE_UNKNOWN_CHUNKS
+
+# The first way to read user chunks is to have libpng save them for a later call
+# to png_get_unknown_chunks, the application must call
+# png_set_keep_unknown_chunks to cause this to actually happen (see png.h)
+option SAVE_UNKNOWN_CHUNKS requires READ requires SET_UNKNOWN_CHUNKS
+option SAVE_UNKNOWN_CHUNKS enables READ_UNKNOWN_CHUNKS STORE_UNKNOWN_CHUNKS
+
+# The second approach is to use an application provided callback to process the
+# chunks, the callback can either handle the chunk entirely itself or request
+# that libpng store the chunk for later retrieval via png_get_unknown_chunks.
+#
+# Note that there is no 'WRITE_USER_CHUNKS' so the USER_CHUNKS option is always
+# the same as READ_USER_CHUNKS at present
+option READ_USER_CHUNKS requires READ requires UNKNOWN_CHUNKS
+option READ_USER_CHUNKS enables READ_UNKNOWN_CHUNKS USER_CHUNKS
+
+# Two further options are provided to allow detailed control of the handling.
+# The first enables png_set_keep_unknown_chunks; this allows the default to be
+# changed from discarding unknown chunks and allows per-chunk control.  This is
+# required to use the SAVE_UNKNOWN_CHUNKS option.  If enabled this option also
+# applies to write (see png.h), otherwise the write API simply writes all the
+# chunks it is given.
+#
+# The second option extends the unknown handling to allow known chunks to be
+# handled as though they were unknown.  This option doesn't change any APIs, it
+# merely turns on the code to check known as well as unknown chunks.
+#
+# This option no longer affects the write code.  It can be safely disabled and
+# will prevent applications stopping libpng reading known chunks.
+option SET_UNKNOWN_CHUNKS requires UNKNOWN_CHUNKS
+option HANDLE_AS_UNKNOWN requires SET_UNKNOWN_CHUNKS
+
+# The following options are derived from the above and should not be turned on
+# explicitly.
+option READ_UNKNOWN_CHUNKS requires UNKNOWN_CHUNKS disabled
+option STORE_UNKNOWN_CHUNKS requires UNKNOWN_CHUNKS disabled
 
 option CONVERT_tIME requires WRITE_ANCILLARY_CHUNKS
 # The "tm" structure is not supported on WindowsCE
@@ -648,13 +739,10 @@ option CONVERT_tIME requires WRITE_ANCILLARY_CHUNKS
 
 option WRITE_FILTER requires WRITE
 
-option WRITE_UNKNOWN_CHUNKS requires WRITE
-
-option HANDLE_AS_UNKNOWN
-
-option SAVE_INT_32 requires WRITE
-
-# png_save_int_32 is required by the ancillary chunks oFFs and pCAL
+option SAVE_INT_32 disabled
+# png_save_int_32 is required internally for writing the ancillary chunks oFFs
+# and pCAL and for both reading and writing iCCP (for the generation/checking of
+# the corresponding cHRM/gAMA chunks) if full ICC is supported.
 
 # added at libpng-1.5.4
 
@@ -692,7 +780,7 @@ option WRITE_CHECK_FOR_INVALID_INDEX requires WRITE CHECK_FOR_INVALID_INDEX
 # Simplified API options (added at libpng-1.6.0)
 # Read:
 option SIMPLIFIED_READ requires SEQUENTIAL_READ READ_TRANSFORMS SETJMP
-option SIMPLIFIED_READ requires BENIGN_ERRORS
+option SIMPLIFIED_READ requires BENIGN_ERRORS READ_GAMMA
 option SIMPLIFIED_READ enables READ_EXPAND READ_16BIT READ_EXPAND_16
 option SIMPLIFIED_READ enables READ_SCALE_16_TO_8 READ_RGB_TO_GRAY
 option SIMPLIFIED_READ enables READ_ALPHA_MODE READ_BACKGROUND READ_STRIP_ALPHA

scripts/pnglibconf.h.prebuilt

@@ -3,7 +3,7 @@
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng 1.6.0beta25 - June 16, 2012 */
+/* Libpng 1.6.0beta35 - December 22, 2012 */
 
 /* Copyright (c) 1998-2012 Glenn Randers-Pehrson */
 
@@ -34,8 +34,13 @@
 #define PNG_QUANTIZE_RED_BITS 5
 #define PNG_sCAL_PRECISION 5
 #define PNG_sRGB_PROFILE_CHECKS 2
+#define PNG_TEXT_Z_DEFAULT_COMPRESSION Z_DEFAULT_COMPRESSION
+#define PNG_TEXT_Z_DEFAULT_STRATEGY Z_DEFAULT_STRATEGY
 #define PNG_WEIGHT_SHIFT 8
 #define PNG_ZBUF_SIZE 8192
+#define PNG_Z_DEFAULT_COMPRESSION Z_DEFAULT_COMPRESSION
+#define PNG_Z_DEFAULT_NOFILTER_STRATEGY Z_DEFAULT_STRATEGY
+#define PNG_Z_DEFAULT_STRATEGY Z_FILTERED
 /* end of settings */
 /* options */
 #define PNG_16BIT_SUPPORTED
@@ -126,12 +131,14 @@
 #define PNG_READ_zTXt_SUPPORTED
 /*#undef PNG_SAFE_LIMITS_SUPPORTED*/
 #define PNG_SAVE_INT_32_SUPPORTED
+#define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_sBIT_SUPPORTED
 #define PNG_sCAL_SUPPORTED
 #define PNG_SEQUENTIAL_READ_SUPPORTED
 #define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
 #define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
 #define PNG_SETJMP_SUPPORTED
+#define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SET_USER_LIMITS_SUPPORTED
 #define PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
 #define PNG_SIMPLIFIED_READ_BGR_SUPPORTED
@@ -142,6 +149,7 @@
 #define PNG_sPLT_SUPPORTED
 #define PNG_sRGB_SUPPORTED
 #define PNG_STDIO_SUPPORTED
+#define PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_tEXt_SUPPORTED
 #define PNG_TEXT_SUPPORTED
 #define PNG_TIME_RFC1123_SUPPORTED

scripts/symbols.def

@@ -5,7 +5,7 @@
 LIBRARY
 
 EXPORTS
-;Version 1.6.0beta25
+;Version 1.6.0beta35
  png_access_version_number @1
  png_set_sig_bytes @2
  png_sig_cmp @3
@@ -205,7 +205,6 @@ EXPORTS
  png_get_y_offset_inches @197
  png_get_pHYs_dpi @198
  png_get_io_state @199
-;png_get_io_chunk_name @200
  png_get_uint_32 @201
  png_get_uint_16 @202
  png_get_int_32 @203