Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 6127 insertions, 0 deletions

diff --git a/media/libpng/CHANGES b/media/libpng/CHANGES
new file mode 100644
index 0000000000..366e0f6a7b
--- /dev/null
+++ b/media/libpng/CHANGES
@@ -0,0 +1,6127 @@
+CHANGES - changes for libpng
+
+version 0.1 [March 29, 1995]
+  initial work-in-progress release
+
+version 0.2 [April 1, 1995]
+  added reader into png.h
+  fixed small problems in stub file
+
+version 0.3 [April 8, 1995]
+  added pull reader
+  split up pngwrite.c to several files
+  added pnglib.txt
+  added example.c
+  cleaned up writer, adding a few new transformations
+  fixed some bugs in writer
+  interfaced with zlib 0.5
+  added K&R support
+  added check for 64 KB blocks for 16 bit machines
+
+version 0.4 [April 26, 1995]
+  cleaned up code and commented code
+  simplified time handling into png_time
+  created png_color_16 and png_color_8 to handle color needs
+  cleaned up color type defines
+  fixed various bugs
+  made various names more consistent
+  interfaced with zlib 0.71
+  cleaned up zTXt reader and writer (using zlib's Reset functions)
+  split transformations into pngrtran.c and pngwtran.c
+
+version 0.5 [April 30, 1995]
+  interfaced with zlib 0.8
+  fixed many reading and writing bugs
+  saved using 3 spaces instead of tabs
+
+version 0.6 [May 1, 1995]
+  first beta release
+  added png_large_malloc() and png_large_free()
+  added png_size_t
+  cleaned up some compiler warnings
+  added png_start_read_image()
+
+version 0.7 [June 24, 1995]
+  cleaned up lots of bugs
+  finished dithering and other stuff
+  added test program
+  changed name from pnglib to libpng
+
+version 0.71 [June 26, 1995]
+  changed pngtest.png for zlib 0.93
+  fixed error in libpng.txt and example.c
+
+version 0.8 [August 20, 1995]
+  cleaned up some bugs
+  added png_set_filler()
+  split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
+  added #define's to remove unwanted code
+  moved png_info_init() to png.c
+  added old_size into png_realloc()
+  added functions to manually set filtering and compression info
+  changed compression parameters based on image type
+  optimized filter selection code
+  added version info
+  changed external functions passing floats to doubles (k&r problems?)
+  put all the configurable stuff in pngconf.h
+  enabled png_set_shift to work with paletted images on read
+  added png_read_update_info() - updates info structure with transformations
+
+Version 0.81 [August, 1995]
+  incorporated Tim Wegner's medium model code (thanks, Tim)
+
+Version 0.82 [September, 1995]
+  [unspecified changes]
+
+Version 0.85 [December, 1995]
+  added more medium model code (almost everything's a far)
+  added i/o, error, and memory callback functions
+  fixed some bugs (16-bit, 4-bit interlaced, etc.)
+  added first run progressive reader (barely tested)
+
+Version 0.86 [January, 1996]
+  fixed bugs
+  improved documentation
+
+Version 0.87 [January, 1996]
+  fixed medium model bugs
+  fixed other bugs introduced in 0.85 and 0.86
+  added some minor documentation
+
+Version 0.88 [January, 1996]
+  fixed progressive bugs
+  replaced tabs with spaces
+  cleaned up documentation
+  added callbacks for read/write and warning/error functions
+
+Version 0.89 [June 5, 1996]
+  Added new initialization API to make libpng work better with shared libs
+    we now have png_create_read_struct(), png_create_write_struct(),
+    png_create_info_struct(), png_destroy_read_struct(), and
+    png_destroy_write_struct() instead of the separate calls to
+    malloc and png_read_init(), png_info_init(), and png_write_init()
+  Changed warning/error callback functions to fix bug - this means you
+    should use the new initialization API if you were using the old
+    png_set_message_fn() calls, and that the old API no longer exists
+    so that people are aware that they need to change their code
+  Changed filter selection API to allow selection of multiple filters
+    since it didn't work in previous versions of libpng anyways
+  Optimized filter selection code
+  Fixed png_set_background() to allow using an arbitrary RGB color for
+    paletted images
+  Fixed gamma and background correction for paletted images, so
+    png_correct_palette is not needed unless you are correcting an
+    external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
+    in pngconf.h) - if nobody uses this, it may disappear in the future.
+  Fixed bug with Borland 64K memory allocation (Alexander Lehmann)
+  Fixed bug in interlace handling (Smarasderagd, I think)
+  Added more error checking for writing and image to reduce invalid files
+  Separated read and write functions so that they won't both be linked
+    into a binary when only reading or writing functionality is used
+  New pngtest image also has interlacing and zTXt
+  Updated documentation to reflect new API
+
+Version 0.89c [June 17, 1996]
+  Bug fixes.
+
+Version 0.90 [January, 1997]
+  Made CRC errors/warnings on critical and ancillary chunks configurable
+  libpng will use the zlib CRC routines by (compile-time) default
+  Changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
+  Added external C++ wrapper statements to png.h (Gilles Dauphin)
+  Allow PNG file to be read when some or all of file signature has already
+    been read from the beginning of the stream.  ****This affects the size
+    of info_struct and invalidates all programs that use a shared libpng****
+  Fixed png_filler() declarations
+  Fixed? background color conversions
+  Fixed order of error function pointers to match documentation
+  Current chunk name is now available in png_struct to reduce the number
+    of nearly identical error messages (will simplify multi-lingual
+    support when available)
+  Try to get ready for unknown-chunk callback functions:
+    - previously read critical chunks are flagged, so the chunk handling
+      routines can determine if the chunk is in the right place
+    - all chunk handling routines have the same prototypes, so we will
+      be able to handle all chunks via a callback mechanism
+  Try to fix Linux "setjmp" buffer size problems
+  Removed png_large_malloc, png_large_free, and png_realloc functions.
+
+Version 0.95 [March, 1997]
+  Fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
+  Fixed bug in PNG file signature compares when start != 0
+  Changed parameter type of png_set_filler(...filler...) from png_byte
+    to png_uint_32
+  Added test for MACOS to ensure that both math.h and fp.h are not #included
+  Added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
+  Added "packswap" transformation, which changes the endianness of
+    packed-pixel bytes (Kevin Bracey)
+  Added "strip_alpha" transformation, which removes the alpha channel of
+    input images without using it (not necessarily a good idea)
+  Added "swap_alpha" transformation, which puts the alpha channel in front
+    of the color bytes instead of after
+  Removed all implicit variable tests which assume NULL == 0 (I think)
+  Changed several variables to "png_size_t" to show 16/32-bit limitations
+  Added new pCAL chunk read/write support
+  Added experimental filter selection weighting (Greg Roelofs)
+  Removed old png_set_rgbx() and png_set_xrgb() functions that have been
+    obsolete for about 2 years now (use png_set_filler() instead)
+  Added macros to read 16- and 32-bit ints directly from buffer, to be
+    used only on those systems that support it (namely PowerPC and 680x0)
+    With some testing, this may become the default for MACOS/PPC systems.
+  Only calculate CRC on data if we are going to use it
+  Added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
+  Added macros for simple libpng debugging output selectable at compile time
+  Removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
+  More description of info_struct in libpng.txt and png.h
+  More instructions in example.c
+  More chunk types tested in pngtest.c
+  Renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
+    png_set_<chunk>.  We now have corresponding png_get_<chunk>
+    functions in pngget.c to get information in info_ptr.  This isolates
+    the application from the internal organization of png_info_struct
+    (good for shared library implementations).
+
+Version 0.96 [May, 1997]
+  Fixed serious bug with < 8bpp images introduced in 0.95
+  Fixed 256-color transparency bug (Greg Roelofs)
+  Fixed up documentation (Greg Roelofs, Laszlo Nyul)
+  Fixed "error" in pngconf.h for Linux setjmp() behavior
+  Fixed DOS medium model support (Tim Wegner)
+  Fixed png_check_keyword() for case with error in static string text
+  Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
+  Added typecasts to quiet compiler errors
+  Added more debugging info
+
+Version 0.97 [January, 1998]
+  Removed PNG_USE_OWN_CRC capability
+  Relocated png_set_crc_action from pngrutil.c to pngrtran.c
+  Fixed typecasts of "new_key", etc. (Andreas Dilger)
+  Added RFC 1152 [sic] date support
+  Fixed bug in gamma handling of 4-bit grayscale
+  Added 2-bit grayscale gamma handling (Glenn R-P)
+  Added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
+  Minor corrections in libpng.txt
+  Added simple sRGB support (Glenn R-P)
+  Easier conditional compiling, e.g.,
+    define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
+    all configurable options can be selected from command-line instead
+    of having to edit pngconf.h (Glenn R-P)
+  Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
+  Added more conditions for png_do_background, to avoid changing
+    black pixels to background when a background is supplied and
+    no pixels are transparent
+  Repaired PNG_NO_STDIO behavior
+  Tested NODIV support and made it default behavior (Greg Roelofs)
+  Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
+  Regularized version numbering scheme and bumped shared-library major
+    version number to 2 to avoid problems with libpng 0.89 apps
+    (Greg Roelofs)
+
+Version 0.98 [January, 1998]
+  Cleaned up some typos in libpng.txt and in code documentation
+  Fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
+  Cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
+  Changed recommendation about file_gamma for PC images to .51 from .45,
+    in example.c and libpng.txt, added comments to distinguish between
+    screen_gamma, viewing_gamma, and display_gamma.
+  Changed all references to RFC1152 to read RFC1123 and changed the
+    PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
+  Added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
+  Changed srgb_intent from png_byte to int to avoid compiler bugs
+
+Version 0.99 [January 30, 1998]
+  Free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
+  Fixed a longstanding "packswap" bug in pngtrans.c
+  Fixed some inconsistencies in pngconf.h that prevented compiling with
+    PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
+  Fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
+  Changed recommendation about file_gamma for PC images to .50 from .51 in
+    example.c and libpng.txt, and changed file_gamma for sRGB images to .45
+  Added a number of functions to access information from the png structure
+    png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
+  Added TARGET_MACOS similar to zlib-1.0.8
+  Define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
+  Added type casting to all png_malloc() function calls
+
+Version 0.99a [January 31, 1998]
+  Added type casts and parentheses to all returns that return a value.(Tim W.)
+
+Version 0.99b [February 4, 1998]
+  Added type cast png_uint_32 on malloc function calls where needed.
+  Changed type of num_hist from png_uint_32 to int (same as num_palette).
+  Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
+  Renamed makefile.elf to makefile.lnx.
+
+Version 0.99c [February 7, 1998]
+  More type casting.  Removed erroneous overflow test in pngmem.c.
+  Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
+  Added UNIX manual pages libpng.3 (incorporating libpng.txt) and  png.5.
+
+Version 0.99d [February 11, 1998]
+  Renamed "far_to_near()" "png_far_to_near()"
+  Revised libpng.3
+  Version 99c "buffered" operations didn't work as intended.  Replaced them
+    with png_memcpy_check() and png_memset_check().
+  Added many "if (png_ptr == NULL) return" to quell compiler warnings about
+    unused png_ptr, mostly in pngget.c and pngset.c.
+  Check for overlength tRNS chunk present when indexed-color PLTE is read.
+  Cleaned up spelling errors in libpng.3/libpng.txt
+  Corrected a problem with png_get_tRNS() which returned undefined trans array
+
+Version 0.99e [February 28, 1998]
+  Corrected png_get_tRNS() again.
+  Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
+  Touched up example.c to make more of it compileable, although the entire
+    file still can't be compiled (Willem van Schaik)
+  Fixed a bug in png_do_shift() (Bryan Tsai)
+  Added a space in png.h prototype for png_write_chunk_start()
+  Replaced pngtest.png with one created with zlib 1.1.1
+  Changed pngtest to report PASS even when file size is different (Jean-loup G.)
+  Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
+
+Version 0.99f [March 5, 1998]
+  Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
+  Moved makefiles into a "scripts" directory, and added INSTALL instruction file
+  Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
+  Added pointers to "note on libpng versions" in makefile.lnx and README
+  Added row callback feature when reading and writing nonprogressive rows
+    and added a test of this feature in pngtest.c
+  Added user transform callbacks, with test of the feature in pngtest.c
+
+Version 0.99g [March 6, 1998, morning]
+  Minor changes to pngtest.c to suppress compiler warnings.
+  Removed "beta" language from documentation.
+
+Version 0.99h [March 6, 1998, evening]
+  Minor changes to previous minor changes to pngtest.c
+  Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
+    and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
+  Added user transform capability
+
+Version 1.00 [March 7, 1998]
+  Changed several typedefs in pngrutil.c
+  Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
+  Replaced "while(1)" with "for(;;)"
+  Added PNGARG() to prototypes in pngtest.c and removed some prototypes
+  Updated some of the makefiles (Tom Lane)
+  Changed some typedefs (s_start, etc.) in pngrutil.c
+  Fixed dimensions of "short_months" array in pngwrite.c
+  Replaced ansi2knr.c with the one from jpeg-v6
+
+Version 1.0.0 [March 8, 1998]
+  Changed name from 1.00 to 1.0.0 (Adam Costello)
+  Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
+
+Version 1.0.0a [March 9, 1998]
+  Fixed three bugs in pngrtran.c to make gamma+background handling consistent
+    (Greg Roelofs)
+  Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
+    for major, minor, and bugfix releases.  This is 10001. (Adam Costello,
+    Tom Lane)
+  Make months range from 1-12 in png_convert_to_rfc1123
+
+Version 1.0.0b [March 13, 1998]
+  Quieted compiler complaints about two empty "for" loops in pngrutil.c
+  Minor changes to makefile.s2x
+  Removed #ifdef/#endif around a png_free() in pngread.c
+
+Version 1.0.1 [March 14, 1998]
+  Changed makefile.s2x to reduce security risk of using a relative pathname
+  Fixed some typos in the documentation (Greg).
+  Fixed a problem with value of "channels" returned by png_read_update_info()
+
+Version 1.0.1a [April 21, 1998]
+  Optimized Paeth calculations by replacing abs() function calls with intrinsics
+  plus other loop optimizations. Improves avg decoding speed by about 20%.
+  Commented out i386istic "align" compiler flags in makefile.lnx.
+  Reduced the default warning level in some makefiles, to make them consistent.
+  Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
+  Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
+  Added grayscale and 16-bit capability to png_do_read_filler().
+  Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
+    too large when writing an image with bit_depth < 8 (Bob Dellaca).
+  Corrected some bugs in the experimental weighted filtering heuristics.
+  Moved a misplaced pngrutil code block that truncates tRNS if it has more
+    than num_palette entries -- test was done before num_palette was defined.
+  Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
+  Changed compiler flags in makefile.wat for better optimization
+    (Pawel Mrochen).
+
+Version 1.0.1b [May 2, 1998]
+  Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
+  Relocated the png_composite macros from pngrtran.c to png.h (Greg).
+  Added makefile.sco (contributed by Mike Hopkirk).
+  Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
+  Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
+  More work on the Paeth-filtering, achieving imperceptible speedup
+    (A Kleinert).
+  More work on loop optimization which may help when compiled with C++
+    compilers.
+  Added warnings when people try to use transforms they've defined out.
+  Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
+  Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
+
+Version 1.0.1c [May 11, 1998]
+  Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
+    filler bytes should have been 0xff instead of 0xf.
+  Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
+  Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
+    out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
+  Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
+    for consistency, in pngconf.h
+  Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
+    to remove unwanted capabilities via the compile line
+  Made some corrections to grammar (which, it's) in documentation (Greg).
+  Corrected example.c, use of row_pointers in png_write_image().
+
+Version 1.0.1d [May 24, 1998]
+  Corrected several statements that used side effects illegally in pngrutil.c
+    and pngtrans.c, that were introduced in version 1.0.1b
+  Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
+  More corrections to example.c, use of row_pointers in png_write_image()
+    and png_read_rows().
+  Added pngdll.mak and pngdef.pas to scripts directory, contributed by
+    Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
+  Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
+  Changed several loops from count-down to count-up, for consistency.
+
+Version 1.0.1e [June 6, 1998]
+  Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
+    added warnings when people try to set png_read_fn and png_write_fn in
+    the same structure.
+  Added a test such that png_do_gamma will be done when num_trans==0
+    for truecolor images that have defined a background.  This corrects an
+    error that was introduced in libpng-0.90 that can cause gamma processing
+    to be skipped.
+  Added tests in png.h to include "trans" and "trans_values" in structures
+    when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
+  Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
+  Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
+  Added capability for user-provided malloc_fn() and free_fn() functions,
+    and revised pngtest.c to demonstrate their use, replacing the
+    PNGTEST_DEBUG_MEM feature.
+  Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
+
+Version 1.0.2 [June 14, 1998]
+  Fixed two bugs in makefile.bor .
+
+Version 1.0.2a [December 30, 1998]
+  Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
+  Fixed a bug in png_do_filler() that made it fail to write filler bytes in
+    the left-most pixel of each row (Kevin Bracey).
+  Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
+    in pngtest.c (Duncan Simpson).
+  Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
+    even when no tIME chunk was present in the source file.
+  Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
+  Fixed a problem in png_read_push_finish_row(), which would not skip some
+    passes that it should skip, for images that are less than 3 pixels high.
+  Interchanged the order of calls to png_do_swap() and png_do_shift()
+    in pngwtran.c (John Cromer).
+  Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
+  Changed "bad adaptive filter type" from error to warning in pngrutil.c .
+  Fixed a documentation error about default filtering with 8-bit indexed-color.
+  Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
+    (L. Peter Deutsch).
+  Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
+  Added png_get_copyright() and png_get_header_version() functions.
+  Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
+  Added information about debugging in libpng.txt and libpng.3 .
+  Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and
+    makefile.sco.
+  Removed lines after Dynamic Dependencies" in makefile.aco .
+  Revised makefile.dec to make a shared library (Jeremie Petit).
+  Removed trailing blanks from all files.
+
+Version 1.0.2a [January 6, 1999]
+  Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
+  Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
+  Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
+  Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
+    which is obsolete.
+
+Version 1.0.3 [January 14, 1999]
+  Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
+  Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.
+
+Version 1.0.3a [August 12, 1999]
+  Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
+    if an attempt is made to read an interlaced image when it's not supported.
+  Added check if png_ptr->trans is defined before freeing it in pngread.c
+  Modified the Y2K statement to include versions back to version 0.71
+  Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
+  Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
+  Replaced leading blanks with tab characters in makefile.hux
+  Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
+  Changed (float)red and (float)green to (double)red, (double)green
+    in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
+  Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
+  Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
+  Updated documentation to refer to the PNG-1.2 specification.
+  Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
+    in makefile.knr, INSTALL, and README (L. Peter Deutsch)
+  Fixed bugs in calculation of the length of rowbytes when adding alpha
+    channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
+  Added function png_set_user_transform_info() to store user_transform_ptr,
+    user_depth, and user_channels into the png_struct, and a function
+    png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
+  Added function png_set_empty_plte_permitted() to make libpng useable
+    in MNG applications.
+  Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
+  Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
+    consistent with PNG-1.2, and allow variance of 500 before complaining.
+  Added assembler code contributed by Intel in file pngvcrd.c and modified
+    makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation,
+    Gilles Vollant)
+  Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
+  Added some aliases for png_set_expand() in pngrtran.c, namely
+    png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
+    (Greg Roelofs, in "PNG: The Definitive Guide").
+  Added makefile.beo for BEOS on X86, contributed by Sander Stok.
+
+Version 1.0.3b [August 26, 1999]
+  Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
+  Changed leading blanks to tabs in all makefiles.
+  Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
+  Made alternate versions of  png_set_expand() in pngrtran.c, namely
+    png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
+    (Greg Roelofs, in "PNG: The Definitive Guide").  Deleted the 1.0.3a aliases.
+  Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
+  Revised calculation of num_blocks in pngmem.c to avoid a potentially
+    negative shift distance, whose results are undefined in the C language.
+  Added a check in pngset.c to prevent writing multiple tIME chunks.
+  Added a check in pngwrite.c to detect invalid small window_bits sizes.
+
+Version 1.0.3d [September 4, 1999]
+  Fixed type casting of igamma in pngrutil.c
+  Added new png_expand functions to scripts/pngdef.pas and pngos2.def
+  Added a demo read_user_transform_fn that examines the row filters in pngtest.c
+
+Version 1.0.4 [September 24, 1999, not distributed publicly]
+  Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
+  Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
+  Made several minor corrections to pngtest.c
+  Renamed the makefiles with longer but more user friendly extensions.
+  Copied the PNG copyright and license to a separate LICENSE file.
+  Revised documentation, png.h, and example.c to remove reference to
+    "viewing_gamma" which no longer appears in the PNG specification.
+  Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
+  Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
+  Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
+    assembler code) and makefile.vcwin32 (doesn't).
+  Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
+  Added a copy of pngnow.png to the distribution.
+
+Version 1.0.4a [September 25, 1999]
+  Increase max_pixel_depth in pngrutil.c if a user transform needs it.
+  Changed several division operations to right-shifts in pngvcrd.c
+
+Version 1.0.4b [September 30, 1999]
+  Added parentheses in line 3732 of pngvcrd.c
+  Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
+
+Version 1.0.4c [October 1, 1999]
+  Added a "png_check_version" function in png.c and pngtest.c that will generate
+    a helpful compiler error if an old png.h is found in the search path.
+  Changed type of png_user_transform_depth|channels from int to png_byte.
+  Added "Libpng is OSI Certified Open Source Software" statement to png.h
+
+Version 1.0.4d [October 6, 1999]
+  Changed 0.45 to 0.45455 in png_set_sRGB()
+  Removed unused PLTE entries from pngnow.png
+  Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
+
+Version 1.0.4e [October 10, 1999]
+  Fixed sign error in pngvcrd.c (Greg Roelofs)
+  Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
+
+Version 1.0.4f [October 15, 1999]
+  Surrounded example.c code with #if 0 .. #endif to prevent people from
+    inadvertently trying to compile it.
+  Changed png_get_header_version() from a function to a macro in png.h
+  Added type casting mostly in pngrtran.c and pngwtran.c
+  Removed some pointless "ptr = NULL" in pngmem.c
+  Added a "contrib" directory containing the source code from Greg's book.
+
+Version 1.0.5 [October 15, 1999]
+  Minor editing of the INSTALL and README files.
+
+Version 1.0.5a [October 23, 1999]
+  Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
+  Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
+  Further optimization and bugfix of pngvcrd.c
+  Revised pngset.c so that it does not allocate or free memory in the user's
+    text_ptr structure.  Instead, it makes its own copy.
+  Created separate write_end_info_struct in pngtest.c for a more severe test.
+  Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
+
+Version 1.0.5b [November 23, 1999]
+  Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
+    PNG_FLAG_WROTE_tIME from flags to mode.
+  Added png_write_info_before_PLTE() function.
+  Fixed some typecasting in contrib/gregbook/*.c
+  Updated scripts/makevms.com and added makevms.com to contrib/gregbook
+    and contrib/pngminus (Martin Zinser)
+
+Version 1.0.5c [November 26, 1999]
+  Moved png_get_header_version from png.h to png.c, to accommodate ansi2knr.
+  Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
+    accommodate making DLL's: Moved usr_png_ver from global variable to function
+    png_get_header_ver() in png.c.  Moved png_sig to png_sig_bytes in png.c and
+    eliminated use of png_sig in pngwutil.c.  Moved the various png_CHNK arrays
+    into pngtypes.h.  Eliminated use of global png_pass arrays.  Declared the
+    png_CHNK and png_pass arrays to be "const".  Made the global arrays
+    available to applications (although none are used in libpng itself) when
+    PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
+  Removed some extraneous "-I" from contrib/pngminus/makefile.std
+  Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
+  Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
+
+Version 1.0.5d [November 29, 1999]
+  Add type cast (png_const_charp) two places in png.c
+  Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
+  Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
+    to applications a macro "PNG_USE_LOCAL_ARRAYS".
+  comment out (with #ifdef) all the new declarations when
+    PNG_USE_GLOBAL_ARRAYS is defined.
+  Added PNG_EXPORT_VAR macro to accommodate making DLL's.
+
+Version 1.0.5e [November 30, 1999]
+  Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
+    structure; refactored the inflate/deflate support to make adding new chunks
+    with trailing compressed parts easier in the future, and added new functions
+    png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
+    png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
+    NOTE: Applications that write text chunks MUST define png_text->lang
+    before calling png_set_text(). It must be set to NULL if you want to
+    write tEXt or zTXt chunks.  If you want your application to be able to
+    run with older versions of libpng, use
+
+      #ifdef PNG_iTXt_SUPPORTED
+         png_text[i].lang = NULL;
+      #endif
+
+  Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
+    offsets (Eric S. Raymond).
+  Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
+    PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
+    macros, leaving the separate macros also available.
+  Removed comments on #endifs at the end of many short, non-nested #if-blocks.
+
+Version 1.0.5f [December 6, 1999]
+  Changed makefile.solaris to issue a warning about potential problems when
+    the ucb "ld" is in the path ahead of the ccs "ld".
+  Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
+  Added sCAL chunk support (Eric S. Raymond).
+
+Version 1.0.5g [December 7, 1999]
+  Fixed "png_free_spallettes" typo in png.h
+  Added code to handle new chunks in pngpread.c
+  Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
+  Added "translated_key" to png_text structure and png_write_iTXt().
+  Added code in pngwrite.c to work around a newly discovered zlib bug.
+
+Version 1.0.5h [December 10, 1999]
+  NOTE: regarding the note for version 1.0.5e, the following must also
+    be included in your code:
+        png_text[i].translated_key = NULL;
+  Unknown chunk handling is now supported.
+  Option to eliminate all floating point support was added.  Some new
+    fixed-point functions such as png_set_gAMA_fixed() were added.
+  Expanded tabs and removed trailing blanks in source files.
+
+Version 1.0.5i [December 13, 1999]
+  Added some type casts to silence compiler warnings.
+  Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
+  Removed leading blanks from a #define in pngvcrd.c
+  Added some parameters to the new png_set_keep_unknown_chunks() function.
+  Added a test for up->location != 0 in the first instance of writing
+    unknown chunks in pngwrite.c
+  Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
+    prevent recursion.
+  Added png_free_hIST() function.
+  Various patches to fix bugs in the sCAL and integer cHRM processing,
+    and to add some convenience macros for use with sCAL.
+
+Version 1.0.5j [December 21, 1999]
+  Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
+    around buggy compilers.
+  Added new type "png_fixed_point" for integers that hold float*100000 values
+  Restored backward compatibility of tEXt/zTXt chunk processing:
+    Restored the first four members of png_text to the same order as v.1.0.5d.
+    Added members "lang_key" and "itxt_length" to png_text struct.  Set
+    text_length=0 when "text" contains iTXt data.  Use the "compression"
+    member to distinguish among tEXt/zTXt/iTXt types.  Added
+    PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
+    The "Note" above, about backward incompatibility of libpng-1.0.5e, no
+    longer applies.
+  Fixed png_read|write_iTXt() to read|write parameters in the right order,
+    and to write the iTXt chunk after IDAT if it appears in the end_ptr.
+  Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
+  Reversed the order of trying to write floating-point and fixed-point gAMA.
+
+Version 1.0.5k [December 27, 1999]
+  Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
+  Added png_handle_as_unknown() function (Glenn)
+  Added png_free_chunk_list() function and chunk_list and num_chunk_list members
+    of png_ptr.
+  Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
+  Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
+    about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
+  Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
+  Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
+  Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
+
+Version 1.0.5l [January 1, 2000]
+  Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
+    for setting a callback function to handle unknown chunks and for
+    retrieving the associated user pointer (Glenn).
+
+Version 1.0.5m [January 7, 2000]
+  Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
+
+Version 1.0.5n [January 9, 2000]
+  Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
+    own memory for info_ptr->palette.  This makes it safe for the calling
+    application to free its copy of the palette any time after it calls
+    png_set_PLTE().
+
+Version 1.0.5o [January 20, 2000]
+  Cosmetic changes only (removed some trailing blanks and TABs)
+
+Version 1.0.5p [January 31, 2000]
+  Renamed pngdll.mak to makefile.bd32
+  Cosmetic changes in pngtest.c
+
+Version 1.0.5q [February 5, 2000]
+  Relocated the makefile.solaris warning about PATH problems.
+  Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
+  Revised makefile.gcmmx
+  Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
+
+Version 1.0.5r [February 7, 2000]
+  Removed superfluous prototype for png_get_itxt from png.h
+  Fixed a bug in pngrtran.c that improperly expanded the background color.
+  Return *num_text=0 from png_get_text() when appropriate, and fix documentation
+    of png_get_text() in libpng.txt/libpng.3.
+
+Version 1.0.5s [February 18, 2000]
+  Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
+    new error handler that's planned for the next libpng release, and changed
+    example.c, pngtest.c, and contrib programs to use this macro.
+  Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
+  Fixed a bug in png_read_png() that caused it to fail to expand some images
+    that it should have expanded.
+  Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
+    in pngget.c
+  Changed the allocation of palette, history, and trans arrays back to
+    the version 1.0.5 method (linking instead of copying) which restores
+    backward compatibility with version 1.0.5.  Added some remarks about
+    that in example.c.  Added "free_me" member to info_ptr and png_ptr
+    and added png_free_data() function.
+  Updated makefile.linux and makefile.gccmmx to make directories conditionally.
+  Made cosmetic changes to pngasmrd.h
+  Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
+  Modified png_read_png() to allocate info_ptr->row_pointers only if it
+    hasn't already been allocated.
+
+Version 1.0.5t [March 4, 2000]
+  Changed png_jmp_env() migration aiding macro to png_jmpbuf().
+  Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
+  Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
+    PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
+  Files in contrib/gregbook were revised to use png_jmpbuf() and to select
+    a 24-bit visual if one is available, and to allow abbreviated options.
+  Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
+  Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
+
+Version 1.0.5u [March 5, 2000]
+  Simplified the code that detects old png.h in png.c and pngtest.c
+  Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
+  Increased precision of rgb_to_gray calculations from 8 to 15 bits and
+    added png_set_rgb_to_gray_fixed() function.
+  Added makefile.bc32 (32-bit Borland C++, C mode)
+
+Version 1.0.5v [March 11, 2000]
+  Added some parentheses to the png_jmpbuf macro definition.
+  Updated references to the zlib home page, which has moved to freesoftware.com.
+  Corrected bugs in documentation regarding png_read_row() and png_write_row().
+  Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
+  Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
+    revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
+
+Version 1.0.6 [March 20, 2000]
+  Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
+  Added makefile.sggcc (SGI IRIX with gcc)
+
+Version 1.0.6d [April 7, 2000]
+  Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
+  Added data_length parameter to png_decompress_chunk() function
+  Revised documentation to remove reference to abandoned png_free_chnk functions
+  Fixed an error in png_rgb_to_gray_fixed()
+  Revised example.c, usage of png_destroy_write_struct().
+  Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
+  Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c
+  Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
+
+Version 1.0.6e [April 9, 2000]
+  Added png_data_freer() function.
+  In the code that checks for over-length tRNS chunks, added check of
+    info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
+  Minor revisions of libpng.txt/libpng.3.
+  Check for existing data and free it if the free_me flag is set, in png_set_*()
+    and png_handle_*().
+  Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED
+    is defined.
+  Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
+    and mentioned the purposes of the two macros in libpng.txt/libpng.3.
+
+Version 1.0.6f [April 14, 2000]
+  Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data.
+  Add checks in png_set_text() for NULL members of the input text structure.
+  Revised libpng.txt/libpng.3.
+  Removed superfluous prototype for png_set_iTXt from png.h
+  Removed "else" from pngread.c, after png_error(), and changed "0" to "length".
+  Changed several png_errors about malformed ancillary chunks to png_warnings.
+
+Version 1.0.6g [April 24, 2000]
+  Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined.
+  Relocated paragraph about png_set_background() in libpng.3/libpng.txt
+    and other revisions (Matthias Benckmann)
+  Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and
+    png_ptr members to restore binary compatibility with libpng-1.0.5
+    (breaks compatibility with libpng-1.0.6).
+
+Version 1.0.6h [April 24, 2000]
+  Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds
+    libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h)
+    This is a temporary change for test purposes.
+
+Version 1.0.6i [May 2, 2000]
+  Rearranged some members at the end of png_info and png_struct, to put
+    unknown_chunks_num and free_me within the original size of the png_structs
+    and free_me, png_read_user_fn, and png_free_fn within the original png_info,
+    because some old applications allocate the structs directly instead of
+    using png_create_*().
+  Added documentation of user memory functions in libpng.txt/libpng.3
+  Modified png_read_png so that it will use user_allocated row_pointers
+    if present, unless free_me directs that it be freed, and added description
+    of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3.
+  Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version
+    1.00) members of png_struct and png_info, to regain binary compatibility
+    when you define this macro.  Capabilities lost in this event
+    are user transforms (new in version 1.0.0),the user transform pointer
+    (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT,
+    the high-level interface, and unknown chunks support (all new in 1.0.6).
+    This was necessary because of old applications that allocate the structs
+    directly as authors were instructed to do in libpng-0.88 and earlier,
+    instead of using png_create_*().
+  Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which
+    can be used to detect codes that directly allocate the structs, and
+    code to check these modes in png_read_init() and png_write_init() and
+    generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED
+    was not defined.
+  Added makefile.intel and updated makefile.watcom (Pawel Mrochen)
+
+Version 1.0.6j [May 3, 2000]
+  Overloaded png_read_init() and png_write_init() with macros that convert
+    calls to png_read_init_2() or png_write_init_2() that check the version
+    and structure sizes.
+
+Version 1.0.7beta11 [May 7, 2000]
+  Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
+    which are no longer used.
+  Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
+    defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXt_SUPPORTED
+    is defined.
+  Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
+    overrun when old applications fill the info_ptr->text structure directly.
+  Added PNGAPI macro, and added it to the definitions of all exported functions.
+  Relocated version macro definitions ahead of the includes of zlib.h and
+    pngconf.h in png.h.
+
+Version 1.0.7beta12 [May 12, 2000]
+  Revised pngset.c to avoid a problem with expanding the png_debug macro.
+  Deleted some extraneous defines from pngconf.h
+  Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
+  Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined.
+  Added png_access_version_number() function.
+  Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
+  Expanded libpng.3/libpng.txt information about png_data_freer().
+
+Version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
+  Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
+    warnings instead of errors, as pngrutil.c does.
+  Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png()
+    will actually write IDATs.
+  Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32.
+  Make png_free_data() ignore its final parameter except when freeing data
+    that can have multiple instances (text, sPLT, unknowns).
+  Fixed a new bug in png_set_rows().
+  Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5.
+  Added png_set_invalid() function.
+  Fixed incorrect illustrations of png_destroy_write_struct() in example.c.
+
+Version 1.0.7beta15 [May 30, 2000]
+  Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce
+    fewer error messages.
+  Rearranged checks for Z_OK to check the most likely path first in pngpread.c
+    and pngwutil.c.
+  Added checks in pngtest.c for png_create_*() returning NULL, and mentioned
+    in libpng.txt/libpng.3 the need for applications to check this.
+  Changed names of png_default_*() functions in pngtest to pngtest_*().
+  Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32.
+  Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c
+  Set each pointer to NULL after freeing it in png_free_data().
+  Worked around a problem in pngconf.h; AIX's strings.h defines an "index"
+    macro that conflicts with libpng's png_color_16.index. (Dimitri
+    Papadapoulos)
+  Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux).
+
+Version 1.0.7beta16 [June 4, 2000]
+  Revised the workaround of AIX string.h "index" bug.
+  Added a check for overlength PLTE chunk in pngrutil.c.
+  Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer
+    indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler.
+  Added a warning in png_decompress_chunk() when it runs out of data, e.g.
+    when it tries to read an erroneous PhotoShop iCCP chunk.
+  Added PNG_USE_DLL macro.
+  Revised the copyright/disclaimer/license notice.
+  Added contrib/msvctest directory
+
+Version 1.0.7rc1 [June 9, 2000]
+  Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA  (0x0400 not 0x0200)
+  Added contrib/visupng directory (Willem van Schaik)
+
+Version 1.0.7beta18 [June 23, 2000]
+  Revised PNGAPI definition, and pngvcrd.c to work with __GCC__
+    and do not redefine PNGAPI if it is passed in via a compiler directive.
+  Revised visupng/PngFile.c to remove returns from within the Try block.
+  Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros.
+  Updated contrib/visupng/cexcept.h to version 1.0.0.
+  Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks.
+
+Version 1.0.7rc2 [June 28, 2000]
+  Updated license to include disclaimers required by UCITA.
+  Fixed "DJBPP" typo in pnggccrd.c introduced in beta18.
+
+Version 1.0.7 [July 1, 2000]
+  Revised the definition of "trans_values" in libpng.3/libpng.txt
+
+Version 1.0.8beta1 [July 8, 2000]
+  Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
+  Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
+    pngwutil.c.
+  Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
+  Removed unused "#include <assert.h>" from png.c
+  Added WindowsCE support.
+  Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment.
+
+Version 1.0.8beta2 [July 10, 2000]
+  Added project files to the wince directory and made further revisions
+    of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
+
+Version 1.0.8beta3 [July 11, 2000]
+  Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
+    for indexed-color input files to avoid potential double-freeing trans array
+    under some unusual conditions; problem was introduced in version 1.0.6f.
+  Further revisions to pngtest.c and files in the wince subdirectory.
+
+Version 1.0.8beta4 [July 14, 2000]
+  Added the files pngbar.png and pngbar.jpg to the distribution.
+  Added makefile.cygwin, and cygwin support in pngconf.h
+  Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)
+
+Version 1.0.8rc1 [July 16, 2000]
+  Revised png_debug() macros and statements to eliminate compiler warnings.
+
+Version 1.0.8 [July 24, 2000]
+  Added png_flush() in pngwrite.c, after png_write_IEND().
+  Updated makefile.hpux to build a shared library.
+
+Version 1.0.9beta1 [November 10, 2000]
+  Fixed typo in scripts/makefile.hpux
+  Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
+  Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
+  Changed "cdrom.com" in documentation to "libpng.org"
+  Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
+  Changed type of "params" from voidp to png_voidp in png_read|write_png().
+  Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h.
+  Revised the 3 instances of WRITEFILE in pngtest.c.
+  Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory.
+  Updated png.rc in dll/msvc project
+  Revised makefile.dec to define and use LIBPATH and INCPATH
+  Increased size of global png_libpng_ver[] array from 12 to 18 chars.
+  Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const.
+  Removed duplicate png_crc_finish() from png_handle_bKGD() function.
+  Added a warning when application calls png_read_update_info() multiple times.
+  Revised makefile.cygwin
+  Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
+  Replaced png_set_empty_plte_permitted() with png_permit_mng_features().
+
+Version 1.0.9beta2 [November 19, 2000]
+  Renamed the "dll" subdirectory "projects".
+  Added borland project files to "projects" subdirectory.
+  Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
+  Add error message in png_set_compression_buffer_size() when malloc fails.
+
+Version 1.0.9beta3 [November 23, 2000]
+  Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
+  Removed the png_flush() in pngwrite.c that crashes some applications
+    that don't set png_output_flush_fn.
+  Added makefile.macosx and makefile.aix to scripts directory.
+
+Version 1.0.9beta4 [December 1, 2000]
+  Change png_chunk_warning to png_warning in png_check_keyword().
+  Increased the first part of msg buffer from 16 to 18 in png_chunk_error().
+
+Version 1.0.9beta5 [December 15, 2000]
+  Added support for filter method 64 (for PNG datastreams embedded in MNG).
+
+Version 1.0.9beta6 [December 18, 2000]
+  Revised png_set_filter() to accept filter method 64 when appropriate.
+  Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
+    help prevent applications from using MNG features in PNG datastreams.
+  Added png_permit_mng_features() function.
+  Revised libpng.3/libpng.txt.  Changed "filter type" to "filter method".
+
+Version 1.0.9rc1 [December 23, 2000]
+  Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c
+  Fixed error handling of unknown compression type in png_decompress_chunk().
+  In pngconf.h, define __cdecl when _MSC_VER is defined.
+
+Version 1.0.9beta7 [December 28, 2000]
+  Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
+  Revised memory management in png_set_hIST and png_handle_hIST in a backward
+    compatible manner.  PLTE and tRNS were revised similarly.
+  Revised the iCCP chunk reader to ignore trailing garbage.
+
+Version 1.0.9beta8 [January 12, 2001]
+  Moved pngasmrd.h into pngconf.h.
+  Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.
+
+Version 1.0.9beta9 [January 15, 2001]
+  Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to
+    wince and msvc project module definition files.
+  Minor revision of makefile.cygwin.
+  Fixed bug with progressive reading of narrow interlaced images in pngpread.c
+
+Version 1.0.9beta10 [January 16, 2001]
+  Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined.
+  Fixed "png_mmx_supported" typo in project definition files.
+
+Version 1.0.9beta11 [January 19, 2001]
+  Updated makefile.sgi to make shared library.
+  Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED
+    by default, for the benefit of DLL forward compatibility.  These will
+    be re-enabled in version 1.2.0.
+
+Version 1.0.9rc2 [January 22, 2001]
+  Revised cygwin support.
+
+Version 1.0.9 [January 31, 2001]
+  Added check of cygwin's ALL_STATIC in pngconf.h
+  Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
+
+Version 1.0.10beta1 [March 14, 2001]
+  Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
+  Reformatted libpng.3 to eliminate bad line breaks.
+  Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
+  Added prototype for png_mmx_support() near the top of pnggccrd.c
+  Moved some error checking from png_handle_IHDR to png_set_IHDR.
+  Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
+  Revised png_mmx_support() function in pnggccrd.c
+  Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
+  Fixed memory leak in contrib/visupng/PngFile.c
+  Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
+  Added warnings when retrieving or setting gamma=0.
+  Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().
+
+Version 1.0.10rc1 [March 23, 2001]
+  Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy,
+    and png_strlen.
+  Revised png_mmx_supported() function in pnggccrd.c to return proper value.
+  Fixed bug in progressive reading (pngpread.c) with small images (height < 8).
+
+Version 1.0.10 [March 30, 2001]
+  Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
+  Added beos project files (Chris Herborth)
+
+Version 1.0.11beta1 [April 3, 2001]
+  Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
+  Removed a no-longer needed AIX work-around from pngconf.h
+  Changed several "//" single-line comments to C-style in pnggccrd.c
+
+Version 1.0.11beta2 [April 11, 2001]
+  Removed PNGAPI from several functions whose prototypes did not have PNGAPI.
+  Updated scripts/pngos2.def
+
+Version 1.0.11beta3 [April 14, 2001]
+  Added checking the results of many instances of png_malloc() for NULL
+
+Version 1.0.11beta4 [April 20, 2001]
+  Undid the changes from version 1.0.11beta3.  Added a check for NULL return
+    from user's malloc_fn().
+  Removed some useless type casts of the NULL pointer.
+  Added makefile.netbsd
+
+Version 1.0.11 [April 27, 2001]
+  Revised makefile.netbsd
+
+Version 1.0.12beta1 [May 14, 2001]
+  Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot)
+  Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h
+  Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings.
+  Eliminated the png_error about apps using png_read|write_init().  Instead,
+    libpng will reallocate the png_struct and info_struct if they are too small.
+    This retains future binary compatibility for old applications written for
+    libpng-0.88 and earlier.
+
+Version 1.2.0beta1 [May 6, 2001]
+  Bumped DLLNUM to 2.
+  Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED
+    by default.
+  Added runtime selection of MMX features.
+  Added png_set_strip_error_numbers function and related macros.
+
+Version 1.2.0beta2 [May 7, 2001]
+  Finished merging 1.2.0beta1 with version 1.0.11
+  Added a check for attempts to read or write PLTE in grayscale PNG datastreams.
+
+Version 1.2.0beta3 [May 17, 2001]
+  Enabled user memory function by default.
+  Modified png_create_struct so it passes user mem_ptr to user memory allocator.
+  Increased png_mng_features flag from png_byte to png_uint_32.
+  Bumped shared-library (so-number) and dll-number to 3.
+
+Version 1.2.0beta4 [June 23, 2001]
+  Check for missing profile length field in iCCP chunk and free chunk_data
+    in case of truncated iCCP chunk.
+  Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc
+  Bumped dll-number from 2 to 3 in makefile.cygwin
+  Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly
+    if user attempts to run it on an 8-bit display.
+  Updated contrib/gregbook
+  Use png_malloc instead of png_zalloc to allocate palette in pngset.c
+  Updated makefile.ibmc
+  Added some typecasts to eliminate gcc 3.0 warnings.  Changed prototypes
+    of png_write_oFFS width and height from png_uint_32 to png_int_32.
+  Updated example.c
+  Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c
+
+Version 1.2.0beta5 [August 8, 2001]
+  Revised contrib/gregbook
+  Revised makefile.gcmmx
+  Revised pnggccrd.c to conditionally compile some thread-unsafe code only
+    when PNG_THREAD_UNSAFE_OK is defined.
+  Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with
+    value exceeding 2^bit_depth-1
+  Revised makefile.sgi and makefile.sggcc
+  Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c
+  Removed restriction that do_invert_mono only operate on 1-bit opaque files
+
+Version 1.2.0 [September 1, 2001]
+  Changed a png_warning() to png_debug() in pnggccrd.c
+  Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC().
+
+Version 1.2.1beta1 [October 19, 2001]
+  Revised makefile.std in contrib/pngminus
+  Include background_1 in png_struct regardless of gamma support.
+  Revised makefile.netbsd and makefile.macosx, added makefile.darwin.
+  Revised example.c to provide more details about using row_callback().
+
+Version 1.2.1beta2 [October 25, 2001]
+  Added type cast to each NULL appearing in a function call, except for
+    WINCE functions.
+  Added makefile.so9.
+
+Version 1.2.1beta3 [October 27, 2001]
+  Removed type casts from all NULLs.
+  Simplified png_create_struct_2().
+
+Version 1.2.1beta4 [November 7, 2001]
+  Revised png_create_info_struct() and png_creat_struct_2().
+  Added error message if png_write_info() was omitted.
+  Type cast NULLs appearing in function calls when _NO_PROTO or
+    PNG_TYPECAST_NULL is defined.
+
+Version 1.2.1rc1 [November 24, 2001]
+  Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL
+    is defined.
+  Changed typecast of "size" argument to png_size_t in pngmem.c calls to
+    the user malloc_fn, to agree with the prototype in png.h
+  Added a pop/push operation to pnggccrd.c, to preserve Eflag (Maxim Sobolev)
+  Updated makefile.sgi to recognize LIBPATH and INCPATH.
+  Updated various makefiles so "make clean" does not remove previous major
+    version of the shared library.
+
+Version 1.2.1rc2 [December 4, 2001]
+  Always allocate 256-entry internal palette, hist, and trans arrays, to
+    avoid out-of-bounds memory reference caused by invalid PNG datastreams.
+  Added a check for prefix_length > data_length in iCCP chunk handler.
+
+Version 1.2.1 [December 7, 2001]
+  None.
+
+Version 1.2.2beta1 [February 22, 2002]
+  Fixed a bug with reading the length of iCCP profiles (Larry Reeves).
+  Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate
+    libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h
+  Revised makefile.darwin to remove "-undefined suppress" option.
+  Added checks for gamma and chromaticity values over 21474.83, which exceed
+    the limit for PNG unsigned 32-bit integers when encoded.
+  Revised calls to png_create_read_struct() and png_create_write_struct()
+    for simpler debugging.
+  Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK)
+
+Version 1.2.2beta2 [February 23, 2002]
+  Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths.
+  Check for invalid image dimensions in png_get_IHDR.
+  Added missing "fi;" in the install target of the SGI makefiles.
+  Added install-static to all makefiles that make shared libraries.
+  Always do gamma compensation when image is partially transparent.
+
+Version 1.2.2beta3 [March 7, 2002]
+  Compute background.gray and background_1.gray even when color_type is RGB
+    in case image gets reduced to gray later.
+  Modified shared-library makefiles to install pkgconfig/libpngNN.pc.
+  Export (with PNGAPI) png_zalloc, png_zfree, and png_handle_as_unknown
+  Removed unused png_write_destroy_info prototype from png.h
+  Eliminated incorrect use of width_mmx from pnggccrd.c in pixel_bytes == 8 case
+  Added install-shared target to all makefiles that make shared libraries.
+  Stopped a double free of palette, hist, and trans when not using free_me.
+  Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64.
+
+Version 1.2.2beta4 [March 8, 2002]
+  Compute background.gray and background_1.gray even when color_type is RGB
+    in case image gets reduced to gray later (Jason Summers).
+  Relocated a misplaced /bin/rm in the "install-shared" makefile targets
+  Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library.
+
+Version 1.2.2beta5 [March 26, 2002]
+  Added missing PNGAPI to several function definitions.
+  Check for invalid bit_depth or color_type in png_get_IHDR(), and
+    check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen).
+  Revised iTXt support to accept NULL for lang and lang_key.
+  Compute gamma for color components of background even when color_type is gray.
+  Changed "()" to "{}" in scripts/libpng.pc.in.
+  Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN
+  Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so
+
+Version 1.2.2beta6 [March 31, 2002]
+
+Version 1.0.13beta1 [March 31, 2002]
+  Prevent png_zalloc() from trying to memset memory that it failed to acquire.
+  Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate).
+  Ensure that the right function (user or default) is used to free the
+    png_struct after an error in png_create_read_struct_2().
+
+Version 1.2.2rc1 [April 7, 2002]
+
+Version 1.0.13rc1 [April 7, 2002]
+  Save the ebx register in pnggccrd.c (Sami Farin)
+  Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner).
+  Updated makefiles to put headers in include/libpng and remove old include/*.h.
+
+Version 1.2.2 [April 15, 2002]
+
+Version 1.0.13 [April 15, 2002]
+  Revised description of png_set_filter() in libpng.3/libpng.txt.
+  Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd
+
+Version 1.0.13patch01 [April 17, 2002]
+
+Version 1.2.2patch01 [April 17, 2002]
+  Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and
+    makefile.sggcc
+  Fixed VER -> PNGVER typo in makefile.macosx and added install-static to
+    install
+  Added install: target to makefile.32sunu and makefile.64sunu
+
+Version 1.0.13patch03 [April 18, 2002]
+
+Version 1.2.2patch03 [April 18, 2002]
+  Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng
+  subdirectory to libpngNN subdirectory without the full pathname.
+  Moved generation of libpng.pc from "install" to "all" in 15 makefiles.
+
+Version 1.2.3rc1 [April 28, 2002]
+  Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos).
+  Added $(DESTDIR) feature to 24 makefiles (Tim Mooney)
+  Fixed bug with $prefix, should be $(prefix) in makefile.hpux.
+  Updated cygwin-specific portion of pngconf.h and revised makefile.cygwin
+  Added a link from libpngNN.pc to libpng.pc in 15 makefiles.
+  Added links from include/libpngNN/*.h to include/*.h in 24 makefiles.
+  Revised makefile.darwin to make relative links without full pathname.
+  Added setjmp() at the end of png_create_*_struct_2() in case user forgets
+    to put one in their application.
+  Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and
+    removed them from module definition files.
+
+Version 1.2.3rc2 [May 1, 2002]
+  Fixed bug in reporting number of channels in pngget.c and pngset.c,
+    that was introduced in version 1.2.2beta5.
+  Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(),
+    png_default_flush(), and png_push_fill_buffer() and included them in
+    module definition files.
+  Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles.
+
+Version 1.2.3rc3 [May 1, 2002]
+  Revised prototype for png_default_flush()
+  Remove old libpng.pc and libpngNN.pc before installing new ones.
+
+Version 1.2.3rc4 [May 2, 2002]
+  Typos in *.def files (png_default_read|write -> png_default_read|write_data)
+  In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc
+  Added libpng-config and libpngNN-config and modified makefiles to install
+    them.
+  Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles
+  Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp
+
+Version 1.2.3rc5 [May 11, 2002]
+  Changed "error" and "message" in prototypes to "error_message" and
+    "warning_message" to avoid namespace conflict.
+  Revised 15 makefiles to build libpng-config from libpng-config-*.in
+  Once more restored png_zalloc and png_zfree to regular nonexported form.
+  Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer
+    to nonexported form, but with PNGAPI, and removed them from module def
+    files.
+
+Version 1.2.3rc6 [May 14, 2002]
+  Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c
+  Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp.
+  Removed leftover libpng-config "sed" script from four makefiles.
+  Revised libpng-config creating script in 16 makefiles.
+
+Version 1.2.3 [May 22, 2002]
+  Revised libpng-config target in makefile.cygwin.
+  Removed description of png_set_mem_fn() from documentation.
+  Revised makefile.freebsd.
+  Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR).
+  Revised projects/msvc/README.txt
+  Changed -lpng to -lpngNN in LDFLAGS in several makefiles.
+
+Version 1.2.4beta1 [May 24, 2002]
+  Added libpng.pc and libpng-config to "all:" target in 16 makefiles.
+  Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH)
+  Added missing "\" before closing double quote in makefile.gcmmx.
+  Plugged various memory leaks; added png_malloc_warn() and png_set_text_2()
+    functions.
+
+Version 1.2.4beta2 [June 25, 2002]
+  Plugged memory leak of png_ptr->current_text (Matt Holgate).
+  Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison)
+  Added -soname to the loader flags in makefile.dec, makefile.sgi, and
+    makefile.sggcc.
+  Added "test-installed" target to makefile.linux, makefile.gcmmx,
+    makefile.sgi, and makefile.sggcc.
+
+Version 1.2.4beta3 [June 28, 2002]
+  Plugged memory leak of row_buf in pngtest.c when there is a png_error().
+  Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data.
+  Added "test-installed" target to makefile.32sunu, makefile.64sunu,
+    makefile.beos, makefile.darwin, makefile.dec, makefile.macosx,
+    makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9.
+
+Version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002]
+  Added "test-installed" target to makefile.cygwin and makefile.sco.
+  Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro.
+
+Version 1.2.4 and 1.0.14 [July 8, 2002]
+  Changed png_warning() to png_error() when width is too large to process.
+
+Version 1.2.4patch01 [July 20, 2002]
+  Revised makefile.cygwin to use DLL number 12 instead of 13.
+
+Version 1.2.5beta1 [August 6, 2002]
+  Added code to contrib/gregbook/readpng2.c to ignore unused chunks.
+  Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11)
+  Removed some stray *.o files from contrib/gregbook.
+  Changed png_error() to png_warning() about "Too much data" in pngpread.c
+    and about "Extra compressed data" in pngrutil.c.
+  Prevent png_ptr->pass from exceeding 7 in png_push_finish_row().
+  Updated makefile.hpgcc
+  Updated png.c and pnggccrd.c handling of return from png_mmx_support()
+
+Version 1.2.5beta2 [August 15, 2002]
+  Only issue png_warning() about "Too much data" in pngpread.c when avail_in
+    is nonzero.
+  Updated makefiles to install a separate libpng.so.3 with its own rpath.
+
+Version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002]
+  Revised makefiles to not remove previous minor versions of shared libraries.
+
+Version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002]
+  Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared
+    library loader directive.
+  Added missing "$OBJSDLL" line to makefile.gcmmx.
+  Added missing "; fi" to makefile.32sunu.
+
+Version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002]
+  Revised libpng-config script.
+
+Version 1.2.5 and 1.0.15 [October 3, 2002]
+  Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux,
+    and makefile.aix.
+  Relocated two misplaced PNGAPI lines in pngtest.c
+
+Version 1.2.6beta1 [October 22, 2002]
+  Commented out warning about uninitialized mmx_support in pnggccrd.c.
+  Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h.
+  Relocated two more misplaced PNGAPI lines in pngtest.c
+  Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams,
+    introduced in version 1.0.2.
+  Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu.
+
+Version 1.2.6beta2 [November 1, 2002]
+  Added libpng-config "--ldopts" output.
+  Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)"
+    in makefiles.
+
+Version 1.2.6beta3 [July 18, 2004]
+  Reverted makefile changes from version 1.2.6beta2 and some of the changes
+    from version 1.2.6beta1; these will be postponed until version 1.2.7.
+    Version 1.2.6 is going to be a simple bugfix release.
+  Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile.
+  Fixed potential overrun in pngerror.c by using strncpy instead of memcpy.
+  Added "#!/bin/sh" at the top of configure, for recognition of the
+    'x' flag under Cygwin (Cosmin).
+  Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin).
+  Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin).
+  Fixed the special memory handler for Borland C under DOS, in pngmem.c
+    (Cosmin).
+  Removed some spurious assignments in pngrutil.c (Cosmin).
+  Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings
+    on 16-bit platforms (Cosmin).
+  Enclosed shift op expressions in parentheses, to silence warnings (Cosmin).
+  Used proper type png_fixed_point, to avoid problems on 16-bit platforms,
+    in png_handle_sRGB() (Cosmin).
+  Added compression_type to png_struct, and optimized the window size
+    inside the deflate stream (Cosmin).
+  Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin).
+  Fixed handling of unknown chunks that come after IDAT (Cosmin).
+  Allowed png_error() and png_warning() to work even if png_ptr == NULL
+    (Cosmin).
+  Replaced row_info->rowbytes with row_bytes in png_write_find_filter()
+    (Cosmin).
+  Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre).
+  Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded
+    values in png.c (Simon-Pierre, Cosmin).
+  Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre).
+  Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc
+    (Simon-Pierre).
+  Moved the definition of PNG_HEADER_VERSION_STRING near the definitions
+    of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin).
+  Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin).
+  Updated scripts/makefile.vc(a)win32 (Cosmin).
+  Updated the MSVC project (Simon-Pierre, Cosmin).
+  Updated the Borland C++ Builder project (Cosmin).
+  Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin).
+  Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin).
+  Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin).
+  Added extra guard around inclusion of Turbo C memory headers, in pngconf.h
+    (Cosmin).
+  Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to
+    projects/cbuilder5/ (Cosmin).
+  Moved projects/visualc6/png32ms.def to scripts/pngw32.def,
+    and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin).
+  Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin).
+  Changed line endings to DOS style in cbuilder5 and visualc6 files, even
+    in the tar.* distributions (Cosmin).
+  Updated contrib/visupng/VisualPng.dsp (Cosmin).
+  Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin).
+  Added a separate distribution with "configure" and supporting files (Junichi).
+
+Version 1.2.6beta4 [July 28, 2004]
+  Added user ability to change png_size_t via a PNG_SIZE_T macro.
+  Added png_sizeof() and png_convert_size() functions.
+  Added PNG_SIZE_MAX (maximum value of a png_size_t variable.
+  Added check in png_malloc_default() for (size_t)size != (png_uint_32)size
+    which would indicate an overflow.
+  Changed sPLT failure action from png_error to png_warning and abandon chunk.
+  Changed sCAL and iCCP failures from png_error to png_warning and abandon.
+  Added png_get_uint_31(png_ptr, buf) function.
+  Added PNG_UINT_32_MAX macro.
+  Renamed PNG_MAX_UINT to PNG_UINT_31_MAX.
+  Made png_zalloc() issue a png_warning and return NULL on potential
+    overflow.
+  Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x
+  Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4.
+  Revised Borland portion of png_malloc() to return NULL or issue
+    png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK.
+  Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove
+    sequential read support.
+  Added some "#if PNG_WRITE_SUPPORTED" blocks.
+  Added #ifdef to remove some redundancy in png_malloc_default().
+  Use png_malloc instead of png_zalloc to allocate the palette.
+
+Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
+  Fixed buffer overflow vulnerability (CVE-2004-0597) in png_handle_tRNS().
+  Fixed NULL dereference vulnerability (CVE-2004-0598) in png_handle_iCCP().
+  Fixed integer overflow vulnerability (CVE-2004-0599) in png_read_png().
+  Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
+    duplicate chunk types to go undetected.
+  Fixed some timestamps in the -config version
+  Rearranged order of processing of color types in png_handle_tRNS().
+  Added ROWBYTES macro to calculate rowbytes without integer overflow.
+  Updated makefile.darwin and removed makefile.macosx from scripts directory.
+  Imposed default one million column, one-million row limits on the image
+    dimensions, and added png_set_user_limits() function to override them.
+  Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro.
+  Fixed wrong cast of returns from png_get_user_width|height_max().
+  Changed some "keep the compiler happy" from empty statements to returns,
+  Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution
+
+Version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
+  Revised makefile.darwin and makefile.solaris.  Removed makefile.macosx.
+  Revised pngtest's png_debug_malloc() to use png_malloc() instead of
+    png_malloc_default() which is not supposed to be exported.
+  Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in
+    pngpread.c.  Bug was introduced in 1.2.6rc1.
+  Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1.
+  Fixed old bug in RGB to Gray transformation.
+  Fixed problem with 64-bit compilers by casting arguments to abs()
+    to png_int_32.
+  Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9).
+  Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin)
+  Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles.
+  Added code to update the row_info->colortype in png_do_read_filler() (MSB).
+
+Version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004]
+  Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid
+    trouble with some 64-bit compilers.  Created PNG_OUT_OF_RANGE() macro.
+  Revised documentation of png_set_keep_unknown_chunks().
+  Check handle_as_unknown status in pngpread.c, as in pngread.c previously.
+  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h
+  Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c
+
+Version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]
+  Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of
+    "pinfo" was out of place).
+
+Version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
+  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
+    section of png.h where they were inadvertently placed in version rc3.
+
+Version 1.2.6 and 1.0.16 [August 15, 2004]
+  Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
+
+Version 1.2.7beta1 [August 26, 2004]
+  Removed unused pngasmrd.h file.
+  Removed references to uu.net for archived files.  Added references to
+    PNG Spec (second edition) and the PNG ISO/IEC Standard.
+  Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR.
+  Fixed bug with "optimized window size" in the IDAT datastream, that
+    causes libpng to write PNG files with incorrect zlib header bytes.
+
+Version 1.2.7beta2 [August 28, 2004]
+  Fixed bug with sCAL chunk and big-endian machines (David Munro).
+  Undid new code added in 1.2.6rc2 to update the color_type in
+    png_set_filler().
+  Added png_set_add_alpha() that updates color type.
+
+Version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004]
+  Revised png_set_strip_filler() to not remove alpha if color_type has alpha.
+
+Version 1.2.7 and 1.0.17 [September 12, 2004]
+  Added makefile.hp64
+  Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin
+
+Version 1.2.8beta1 [November 1, 2004]
+  Fixed bug in png_text_compress() that would fail to complete a large block.
+  Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during
+    strip alpha operation in png_do_strip_filler().
+  Added PNG_1_2_X definition in pngconf.h
+  Use #ifdef to comment out png_info_init in png.c and png_read_init in
+    pngread.c (as of 1.3.0)
+
+Version 1.2.8beta2 [November 2, 2004]
+  Reduce color_type to a nonalpha type after strip alpha operation in
+    png_do_strip_filler().
+
+Version 1.2.8beta3 [November 3, 2004]
+  Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM
+
+Version 1.2.8beta4 [November 12, 2004]
+  Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin).
+  Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin).
+  Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection
+    of data type in deflate (Cosmin).
+  Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of
+    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
+
+Version 1.2.8beta5 [November 20, 2004]
+  Use png_ptr->flags instead of png_ptr->transformations to pass
+    PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI
+    compatibility.
+  Revised handling of SPECIALBUILD, PRIVATEBUILD,
+    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
+
+Version 1.2.8rc1 [November 24, 2004]
+  Moved handling of BUILD macros from pngconf.h to png.h
+  Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently
+    omitted from beta5.
+  Revised scripts/pngw32.rc
+  Despammed mailing addresses by masking "@" with "at".
+  Inadvertently installed a supposedly faster test version of pngrutil.c
+
+Version 1.2.8rc2 [November 26, 2004]
+  Added two missing "\" in png.h
+  Change tests in pngread.c and pngpread.c to
+    if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
+       png_do_read_transformations(png_ptr);
+
+Version 1.2.8rc3 [November 28, 2004]
+  Reverted pngrutil.c to version libpng-1.2.8beta5.
+  Added scripts/makefile.elf with supporting code in pngconf.h for symbol
+    versioning (John Bowler).
+
+Version 1.2.8rc4 [November 29, 2004]
+  Added projects/visualc7 (Simon-pierre).
+
+Version 1.2.8rc5 [November 29, 2004]
+  Fixed new typo in scripts/pngw32.rc
+
+Version 1.2.8 [December 3, 2004]
+  Removed projects/visualc7, added projects/visualc71.
+
+Version 1.2.9beta1 [February 21, 2006]
+  Initialized some structure members in pngwutil.c to avoid gcc-4.0.0 complaints
+  Revised man page and libpng.txt to make it clear that one should not call
+    png_read_end or png_write_end after png_read_png or png_write_png.
+  Updated references to png-mng-implement mailing list.
+  Fixed an incorrect typecast in pngrutil.c
+  Added PNG_NO_READ_SUPPORTED conditional for making a write-only library.
+  Added PNG_NO_WRITE_INTERLACING_SUPPORTED conditional.
+  Optimized alpha-inversion loops in pngwtran.c
+  Moved test for nonzero gamma outside of png_build_gamma_table() in pngrtran.c
+  Make sure num_trans is <= 256 before copying data in png_set_tRNS().
+  Make sure num_palette is <= 256 before copying data in png_set_PLTE().
+  Interchanged order of write_swap_alpha and write_invert_alpha transforms.
+  Added parentheses in the definition of PNG_LIBPNG_BUILD_TYPE (Cosmin).
+  Optimized zlib window flag (CINFO) in contrib/pngsuite/*.png (Cosmin).
+  Updated scripts/makefile.bc32 for Borland C++ 5.6 (Cosmin).
+  Exported png_get_uint_32, png_save_uint_32, png_get_uint_16, png_save_uint_16,
+    png_get_int_32, png_save_int_32, png_get_uint_31 (Cosmin).
+  Added type cast (png_byte) in png_write_sCAL() (Cosmin).
+  Fixed scripts/makefile.cygwin (Christian Biesinger, Cosmin).
+  Default iTXt support was inadvertently enabled.
+
+Version 1.2.9beta2 [February 21, 2006]
+  Check for png_rgb_to_gray and png_gray_to_rgb read transformations before
+    checking for png_read_dither in pngrtran.c
+  Revised checking of chromaticity limits to accommodate extended RGB
+    colorspace (John Denker).
+  Changed line endings in some of the project files to CRLF, even in the
+    "Unix" tar distributions (Cosmin).
+  Made png_get_int_32 and png_save_int_32 always available (Cosmin).
+  Updated scripts/pngos2.def, scripts/pngw32.def and projects/wince/png32ce.def
+    with the newly exported functions.
+  Eliminated distributions without the "configure" script.
+  Updated INSTALL instructions.
+
+Version 1.2.9beta3 [February 24, 2006]
+  Fixed CRCRLF line endings in contrib/visupng/VisualPng.dsp
+  Made libpng.pc respect EXEC_PREFIX (D. P. Kreil, J. Bowler)
+  Removed reference to pngasmrd.h from Makefile.am
+  Renamed CHANGES to ChangeLog.
+  Renamed LICENSE to COPYING.
+  Renamed ANNOUNCE to NEWS.
+  Created AUTHORS file.
+
+Version 1.2.9beta4 [March 3, 2006]
+  Changed definition of PKGCONFIG from $prefix/lib to $libdir in configure.ac
+  Reverted to filenames LICENSE and ANNOUNCE; removed AUTHORS and COPYING.
+  Removed newline from the end of some error and warning messages.
+  Removed test for sqrt() from configure.ac and configure.
+  Made swap tables in pngtrans.c PNG_CONST (Carlo Bramix).
+  Disabled default iTXt support that was inadvertently enabled in
+    libpng-1.2.9beta1.
+  Added "OS2" to list of systems that don't need underscores, in pnggccrd.c
+  Removed libpng version and date from *.c files.
+
+Version 1.2.9beta5 [March 4, 2006]
+  Removed trailing blanks from source files.
+  Put version and date of latest change in each source file, and changed
+    copyright year accordingly.
+  More cleanup of configure.ac, Makefile.am, and associated scripts.
+  Restored scripts/makefile.elf which was inadvertently deleted.
+
+Version 1.2.9beta6 [March 6, 2006]
+  Fixed typo (RELEASE) in configuration files.
+
+Version 1.2.9beta7 [March 7, 2006]
+  Removed libpng.vers and libpng.sym from libpng12_la_SOURCES in Makefile.am
+  Fixed inconsistent #ifdef's around png_sig_bytes() and png_set_sCAL_s()
+    in png.h.
+  Updated makefile.elf as suggested by debian.
+  Made cosmetic changes to some makefiles, adding LN_SF and other macros.
+  Made some makefiles accept "exec_prefix".
+
+Version 1.2.9beta8 [March 9, 2006]
+  Fixed some "#if defined (..." which should be "#if defined(..."
+    Bug introduced in libpng-1.2.8.
+  Fixed inconsistency in definition of png_default_read_data()
+  Restored blank that was lost from makefile.sggcc "clean" target in beta7.
+  Revised calculation of "current" and "major" for irix in ltmain.sh
+  Changed "mkdir" to "MKDIR_P" in some makefiles.
+  Separated PNG_EXPAND and PNG_EXPAND_tRNS.
+  Added png_set_expand_gray_1_2_4_to_8() and deprecated
+    png_set_gray_1_2_4_to_8() which also expands tRNS to alpha.
+
+Version 1.2.9beta9 [March 10, 2006]
+  Include "config.h" in pngconf.h when available.
+  Added some checks for NULL png_ptr or NULL info_ptr (timeless)
+
+Version 1.2.9beta10 [March 20, 2006]
+  Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin)
+  Made pnggccrd.c PIC-compliant (Christian Aichinger).
+  Added makefile.mingw (Wolfgang Glas).
+  Revised pngconf.h MMX checking.
+
+Version 1.2.9beta11 [March 22, 2006]
+  Fixed out-of-order declaration in pngwrite.c that was introduced in beta9
+  Simplified some makefiles by using LIBSO, LIBSOMAJ, and LIBSOVER macros.
+
+Version 1.2.9rc1 [March 31, 2006]
+  Defined PNG_USER_PRIVATEBUILD when including "pngusr.h" (Cosmin).
+  Removed nonsensical assertion check from pngtest.c (Cosmin).
+
+Version 1.2.9 [April 14, 2006]
+  Revised makefile.beos and added "none" selector in ltmain.sh
+
+Version 1.2.10beta1 [April 15, 2006]
+  Renamed "config.h" to "png_conf.h" and revised Makefile.am to add
+    -DPNG_BUILDING_LIBPNG to compile directive, and modified pngconf.h
+    to include png_conf.h only when PNG_BUILDING_LIBPNG is defined.
+
+Version 1.2.10beta2 [April 15, 2006]
+  Manually updated Makefile.in and configure.  Changed png_conf.h.in
+    back to config.h.
+
+Version 1.2.10beta3 [April 15, 2006]
+  Change png_conf.h back to config.h in pngconf.h.
+
+Version 1.2.10beta4 [April 16, 2006]
+  Change PNG_BUILDING_LIBPNG to PNG_CONFIGURE_LIBPNG in config/Makefile*.
+
+Version 1.2.10beta5 [April 16, 2006]
+  Added a configure check for compiling assembler code in pnggccrd.c
+
+Version 1.2.10beta6 [April 17, 2006]
+  Revised the configure check for pnggccrd.c
+  Moved -DPNG_CONFIGURE_LIBPNG into @LIBPNG_DEFINES@
+  Added @LIBPNG_DEFINES@ to arguments when building libpng.sym
+
+Version 1.2.10beta7 [April 18, 2006]
+  Change "exec_prefix=$prefix" to "exec_prefix=$(prefix)" in makefiles.
+
+Version 1.2.10rc1 [April 19, 2006]
+  Ensure pngconf.h doesn't define both PNG_USE_PNGGCCRD and PNG_USE_PNGVCRD
+  Fixed "LN_FS" typo in makefile.sco and makefile.solaris.
+
+Version 1.2.10rc2 [April 20, 2006]
+  Added a backslash between -DPNG_CONFIGURE_LIBPNG and -DPNG_NO_ASSEMBLER_CODE
+   in configure.ac and configure
+  Made the configure warning about versioned symbols less arrogant.
+
+Version 1.2.10rc3 [April 21, 2006]
+  Added a note in libpng.txt that png_set_sig_bytes(8) can be used when
+    writing an embedded PNG without the 8-byte signature.
+  Revised makefiles and configure to avoid making links to libpng.so.*
+
+Version 1.2.10 [April 23, 2006]
+  Reverted configure to "rc2" state.
+
+Version 1.2.11beta1 [May 31, 2006]
+  scripts/libpng.pc.in contained "configure" style version info and would
+    not work with makefiles.
+  The shared-library makefiles were linking to libpng.so.0 instead of
+    libpng.so.3 compatibility as the library.
+
+Version 1.2.11beta2 [June 2, 2006]
+  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+    buffer overflow.
+  Fixed bug in example.c (png_set_palette_rgb -> png_set_palette_to_rgb)
+
+Version 1.2.11beta3 [June 5, 2006]
+  Prepended "#! /bin/sh" to ltmail.sh and contrib/pngminus/*.sh (Cosmin).
+  Removed the accidental leftover Makefile.in~ (Cosmin).
+  Avoided potential buffer overflow and optimized buffer in
+    png_write_sCAL(), png_write_sCAL_s() (Cosmin).
+  Removed the include directories and libraries from CFLAGS and LDFLAGS
+    in scripts/makefile.gcc (Nelson A. de Oliveira, Cosmin).
+
+Version 1.2.11beta4 [June 6, 2006]
+  Allow zero-length IDAT chunks after the entire zlib datastream, but not
+    after another intervening chunk type.
+
+Version 1.0.19rc1, 1.2.11rc1 [June 13, 2006]
+  Deleted extraneous square brackets from [config.h] in configure.ac
+
+Version 1.0.19rc2, 1.2.11rc2 [June 14, 2006]
+  Added prototypes for PNG_INCH_CONVERSIONS functions to png.h
+  Revised INSTALL and autogen.sh
+  Fixed typo in several makefiles (-W1 should be -Wl)
+  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
+
+Version 1.0.19rc3, 1.2.11rc3 [June 15, 2006]
+  Removed the new typedefs for 64-bit systems (delay until version 1.4.0)
+  Added one zero element to png_gamma_shift[] array in pngrtran.c to avoid
+    reading out of bounds.
+
+Version 1.0.19rc4, 1.2.11rc4 [June 15, 2006]
+  Really removed the new typedefs for 64-bit systems.
+
+Version 1.0.19rc5, 1.2.11rc5 [June 22, 2006]
+  Removed png_sig_bytes entry from scripts/pngw32.def
+
+Version 1.0.19, 1.2.11 [June 26, 2006]
+  None.
+
+Version 1.0.20, 1.2.12 [June 27, 2006]
+  Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+    buffer overflow.
+
+Version 1.2.13beta1 [October 2, 2006]
+  Removed AC_FUNC_MALLOC from configure.ac
+  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
+  Change "logical" to "bitwise" throughout documentation.
+  Detect and fix attempt to write wrong iCCP profile length (CVE-2006-7244)
+
+Version 1.0.21, 1.2.13 [November 14, 2006]
+  Fix potential buffer overflow in sPLT chunk handler.
+  Fix Makefile.am to not try to link to noexistent files.
+  Check all exported functions for NULL png_ptr.
+
+Version 1.2.14beta1 [November 17, 2006]
+  Relocated three misplaced tests for NULL png_ptr.
+  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
+  Build configure with autoconf-2.60 instead of 2.59
+
+Version 1.2.14beta2 [November 17, 2006]
+  Added some typecasts in png_zalloc().
+
+Version 1.2.14rc1 [November 20, 2006]
+  Changed "strtod" to "png_strtod" in pngrutil.c
+
+Version 1.0.22, 1.2.14    [November 27, 2006]
+  Added missing "$(srcdir)" in Makefile.am and Makefile.in
+
+Version 1.2.15beta1 [December 3, 2006]
+  Generated configure with autoconf-2.61 instead of 2.60
+  Revised configure.ac to update libpng.pc and libpng-config.
+
+Version 1.2.15beta2 [December 3, 2006]
+  Always export MMX asm functions, just stubs if not building pnggccrd.c
+
+Version 1.2.15beta3 [December 4, 2006]
+  Add "png_bytep" typecast to profile while calculating length in pngwutil.c
+
+Version 1.2.15beta4 [December 7, 2006]
+  Added scripts/CMakeLists.txt
+  Changed PNG_NO_ASSEMBLER_CODE to PNG_NO_MMX_CODE in scripts, like 1.4.0beta
+
+Version 1.2.15beta5 [December 7, 2006]
+  Changed some instances of PNG_ASSEMBLER_* to PNG_MMX_* in pnggccrd.c
+  Revised scripts/CMakeLists.txt
+
+Version 1.2.15beta6 [December 13, 2006]
+  Revised scripts/CMakeLists.txt and configure.ac
+
+Version 1.2.15rc1 [December 18, 2006]
+  Revised scripts/CMakeLists.txt
+
+Version 1.2.15rc2 [December 21, 2006]
+  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
+  Added scripts/makefile.nommx
+
+Version 1.2.15rc3 [December 25, 2006]
+  Fixed shared library numbering error that was introduced in 1.2.15beta6.
+
+Version 1.2.15rc4 [December 27, 2006]
+  Fixed handling of rgb_to_gray when png_ptr->color.gray isn't set.
+
+Version 1.2.15rc5 [December 31, 2006]
+  Revised handling of rgb_to_gray.
+
+Version 1.2.15 [January 5, 2007]
+  Added some (unsigned long) typecasts in pngtest.c to avoid printing errors.
+
+Version 1.2.16beta1 [January 6, 2007]
+  Fix bugs in makefile.nommx
+
+Version 1.2.16beta2 [January 16, 2007]
+  Revised scripts/CMakeLists.txt
+
+Version 1.2.16 [January 31, 2007]
+  No changes.
+
+Version 1.2.17beta1 [March 6, 2007]
+  Revised scripts/CMakeLists.txt to install both shared and static libraries.
+  Deleted a redundant line from pngset.c.
+
+Version 1.2.17beta2 [April 26, 2007]
+  Relocated misplaced test for png_ptr == NULL in pngpread.c
+  Change "==" to "&" for testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN
+    flags.
+  Changed remaining instances of PNG_ASSEMBLER_* to PNG_MMX_*
+  Added pngerror() when write_IHDR fails in deflateInit2().
+  Added "const" to some array declarations.
+  Mention examples of libpng usage in the libpng*.txt and libpng.3 documents.
+
+Version 1.2.17rc1 [May 4, 2007]
+  No changes.
+
+Version 1.2.17rc2 [May 8, 2007]
+  Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications
+    calling set_unknown_chunk_location() need them.
+  Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in
+    png_set_expand_gray_1_2_4_to_8().
+  Added png_ptr->unknown_chunk to hold working unknown chunk data, so it
+    can be free'ed in case of error.  Revised unknown chunk handling in
+    pngrutil.c and pngpread.c to use this structure.
+
+Version 1.2.17rc3 [May 8, 2007]
+  Revised symbol-handling in configure script.
+
+Version 1.2.17rc4 [May 10, 2007]
+  Revised unknown chunk handling to avoid storing unknown critical chunks.
+
+Version 1.0.25 [May 15, 2007]
+Version 1.2.17 [May 15, 2007]
+  Added "png_ptr->num_trans=0" before error return in png_handle_tRNS,
+    to eliminate a vulnerability (CVE-2007-2445, CERT VU#684664)
+
+Version 1.0.26 [May 15, 2007]
+Version 1.2.18 [May 15, 2007]
+  Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script
+
+Version 1.2.19beta1 [May 18, 2007]
+  Changed "const static" to "static PNG_CONST" everywhere, mostly undoing
+    change of libpng-1.2.17beta2.  Changed other "const" to "PNG_CONST"
+  Changed some handling of unused parameters, to avoid compiler warnings.
+    "if (unused == NULL) return;" becomes "unused = unused".
+
+Version 1.2.19beta2 [May 18, 2007]
+  Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier)
+
+Version 1.2.19beta3 [May 19, 2007]
+  Add some "png_byte" typecasts in png_check_keyword() and write new_key
+  instead of key in zTXt chunk (Kevin Ryde).
+
+Version 1.2.19beta4 [May 21, 2007]
+  Add png_snprintf() function and use it in place of sprint() for improved
+    defense against buffer overflows.
+
+Version 1.2.19beta5 [May 21, 2007]
+  Fixed png_handle_tRNS() to only use the valid bits of tRNS value.
+  Changed handling of more unused parameters, to avoid compiler warnings.
+  Removed some PNG_CONST in pngwutil.c to avoid compiler warnings.
+
+Version 1.2.19beta6 [May 22, 2007]
+  Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c
+  Added a special "_MSC_VER" case that defines png_snprintf to _snprintf
+
+Version 1.2.19beta7 [May 22, 2007]
+  Squelched png_squelch_warnings() in pnggccrd.c and added
+    an #ifdef PNG_MMX_CODE_SUPPORTED block around the declarations that caused
+    the warnings that png_squelch_warnings was squelching.
+
+Version 1.2.19beta8 [May 22, 2007]
+  Removed __MMX__ from test in pngconf.h.
+
+Version 1.2.19beta9 [May 23, 2007]
+  Made png_squelch_warnings() available via PNG_SQUELCH_WARNINGS macro.
+  Revised png_squelch_warnings() so it might work.
+  Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86.
+
+Version 1.2.19beta10 [May 24, 2007]
+  Resquelched png_squelch_warnings(), use "__attribute__((used))" instead.
+
+Version 1.4.0beta1 [April 20, 2006]
+  Enabled iTXt support (changes png_struct, thus requires so-number change).
+  Cleaned up PNG_ASSEMBLER_CODE_SUPPORTED vs PNG_MMX_CODE_SUPPORTED
+  Eliminated PNG_1_0_X and PNG_1_2_X macros.
+  Removed deprecated functions png_read_init, png_write_init, png_info_init,
+    png_permit_empty_plte, png_set_gray_1_2_4_to_8, png_check_sig, and
+    removed the deprecated macro PNG_MAX_UINT.
+  Moved "PNG_INTERNAL" parts of png.h and pngconf.h into pngintrn.h
+  Removed many WIN32_WCE #ifdefs (Cosmin).
+  Reduced dependency on C-runtime library when on Windows (Simon-Pierre)
+  Replaced sprintf() with png_sprintf() (Simon-Pierre)
+
+Version 1.4.0beta2 [April 20, 2006]
+  Revised makefiles and configure to avoid making links to libpng.so.*
+  Moved some leftover MMX-related defines from pngconf.h to pngintrn.h
+  Updated scripts/pngos2.def, pngw32.def, and projects/wince/png32ce.def
+
+Version 1.4.0beta3 [May 10, 2006]
+  Updated scripts/pngw32.def to comment out MMX functions.
+  Added PNG_NO_GET_INT_32 and PNG_NO_SAVE_INT_32 macros.
+  Scripts/libpng.pc.in contained "configure" style version info and would
+    not work with makefiles.
+  Revised pngconf.h and added pngconf.h.in, so makefiles and configure can
+    pass defines to libpng and applications.
+
+Version 1.4.0beta4 [May 11, 2006]
+  Revised configure.ac, Makefile.am, and many of the makefiles to write
+    their defines in pngconf.h.
+
+Version 1.4.0beta5 [May 15, 2006]
+  Added a missing semicolon in Makefile.am and Makefile.in
+  Deleted extraneous square brackets from configure.ac
+
+Version 1.4.0beta6 [June 2, 2006]
+  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+    buffer overflow.
+  Changed sonum from 0 to 1.
+  Removed unused prototype for png_check_sig() from png.h
+
+Version 1.4.0beta7 [June 16, 2006]
+  Exported png_write_sig (Cosmin).
+  Optimized buffer in png_handle_cHRM() (Cosmin).
+  Set pHYs = 2835 x 2835 pixels per meter, and added
+    sCAL = 0.352778e-3 x 0.352778e-3 meters, in pngtest.png (Cosmin).
+  Added png_set_benign_errors(), png_benign_error(), png_chunk_benign_error().
+  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
+  Added "(unsigned long)" typecast on png_uint_32 variables in printf lists.
+
+Version 1.4.0beta8 [June 22, 2006]
+  Added demonstration of user chunk support in pngtest.c, to support the
+    public sTER chunk and a private vpAg chunk.
+
+Version 1.4.0beta9 [July 3, 2006]
+  Removed ordinals from scripts/pngw32.def and removed png_info_int and
+    png_set_gray_1_2_4_to_8 entries.
+  Inline call of png_get_uint_32() in png_get_uint_31().
+  Use png_get_uint_31() to get vpAg width and height in pngtest.c
+  Removed WINCE and Netware projects.
+  Removed standalone Y2KINFO file.
+
+Version 1.4.0beta10 [July 12, 2006]
+  Eliminated automatic copy of pngconf.h to pngconf.h.in from configure and
+    some makefiles, because it was not working reliably.  Instead, distribute
+    pngconf.h.in along with pngconf.h and cause configure and some of the
+    makefiles to update pngconf.h from pngconf.h.in.
+  Added pngconf.h to DEPENDENCIES in Makefile.am
+
+Version 1.4.0beta11 [August 19, 2006]
+  Removed AC_FUNC_MALLOC from configure.ac.
+  Added a warning when writing iCCP profile with mismatched profile length.
+  Patched pnggccrd.c to assemble on x86_64 platforms.
+  Moved chunk header reading into a separate function png_read_chunk_header()
+    in pngrutil.c.  The chunk header (len+sig) is now serialized in a single
+    operation (Cosmin).
+  Implemented support for I/O states. Added png_ptr member io_state, and
+    functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
+    (Cosmin).
+  Added png_get_io_chunk_name and png_get_io_state to scripts/*.def (Cosmin).
+  Renamed scripts/pngw32.* to scripts/pngwin.* (Cosmin).
+  Removed the include directories and libraries from CFLAGS and LDFLAGS
+    in scripts/makefile.gcc (Cosmin).
+  Used png_save_uint_32() to set vpAg width and height in pngtest.c (Cosmin).
+  Cast to proper type when getting/setting vpAg units in pngtest.c (Cosmin).
+  Added pngintrn.h to the Visual C++ projects (Cosmin).
+  Removed scripts/list (Cosmin).
+  Updated copyright year in scripts/pngwin.def (Cosmin).
+  Removed PNG_TYPECAST_NULL and used standard NULL consistently (Cosmin).
+  Disallowed the user to redefine png_size_t, and enforced a consistent use
+    of png_size_t across libpng (Cosmin).
+  Changed the type of png_ptr->rowbytes, PNG_ROWBYTES() and friends
+    to png_size_t (Cosmin).
+  Removed png_convert_size() and replaced png_sizeof with sizeof (Cosmin).
+  Removed some unnecessary type casts (Cosmin).
+  Changed prototype of png_get_compression_buffer_size() and
+    png_set_compression_buffer_size() to work with png_size_t instead of
+    png_uint_32 (Cosmin).
+  Removed png_memcpy_check() and png_memset_check() (Cosmin).
+  Fixed a typo (png_byte --> png_bytep) in libpng.3 and libpng.txt (Cosmin).
+  Clarified that png_zalloc() does not clear the allocated memory,
+    and png_zalloc() and png_zfree() cannot be PNGAPI (Cosmin).
+  Renamed png_mem_size_t to png_alloc_size_t, fixed its definition in
+    pngconf.h, and used it in all memory allocation functions (Cosmin).
+  Renamed pngintrn.h to pngpriv.h, added a comment at the top of the file
+    mentioning that the symbols declared in that file are private, and
+    updated the scripts and the Visual C++ projects accordingly (Cosmin).
+  Removed circular references between pngconf.h and pngconf.h.in in
+    scripts/makefile.vc*win32 (Cosmin).
+  Removing trailing '.' from the warning and error messages (Cosmin).
+  Added pngdefs.h that is built by makefile or configure, instead of
+    pngconf.h.in (Glenn).
+  Detect and fix attempt to write wrong iCCP profile length.
+
+Version 1.4.0beta12 [October 19, 2006]
+  Changed "logical" to "bitwise" in the documentation.
+  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
+  Add a typecast to stifle compiler warning in pngrutil.c
+
+Version 1.4.0beta13 [November 10, 2006]
+  Fix potential buffer overflow in sPLT chunk handler.
+  Fix Makefile.am to not try to link to noexistent files.
+
+Version 1.4.0beta14 [November 15, 2006]
+  Check all exported functions for NULL png_ptr.
+
+Version 1.4.0beta15 [November 17, 2006]
+  Relocated two misplaced tests for NULL png_ptr.
+  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
+  Build configure with autoconf-2.60 instead of 2.59
+  Add "install: all" in Makefile.am so "configure; make install" will work.
+
+Version 1.4.0beta16 [November 17, 2006]
+  Added a typecast in png_zalloc().
+
+Version 1.4.0beta17 [December 4, 2006]
+  Changed "new_key[79] = '\0';" to "(*new_key)[79] = '\0';" in pngwutil.c
+  Add "png_bytep" typecast to profile while calculating length in pngwutil.c
+
+Version 1.4.0beta18 [December 7, 2006]
+  Added scripts/CMakeLists.txt
+
+Version 1.4.0beta19 [May 16, 2007]
+  Revised scripts/CMakeLists.txt
+  Rebuilt configure and Makefile.in with newer tools.
+  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
+  Added scripts/makefile.nommx
+
+Version 1.4.0beta20 [July 9, 2008]
+  Moved several PNG_HAVE_* macros from pngpriv.h to png.h because applications
+    calling set_unknown_chunk_location() need them.
+  Moved several macro definitions from pngpriv.h to pngconf.h
+  Merge with changes to the 1.2.X branch, as of 1.2.30beta04.
+  Deleted all use of the MMX assembler code and Intel-licensed optimizations.
+  Revised makefile.mingw
+
+Version 1.4.0beta21 [July 21, 2008]
+  Moved local array "chunkdata" from pngrutil.c to the png_struct, so
+    it will be freed by png_read_destroy() in case of a read error (Kurt
+    Christensen).
+
+Version 1.4.0beta22 [July 21, 2008]
+  Change "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking.
+
+Version 1.4.0beta23 [July 22, 2008]
+  Change "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in
+    png_decompress_chunk().
+
+Version 1.4.0beta24 [July 25, 2008]
+  Change all remaining "chunkdata" to "png_ptr->chunkdata" in
+    png_decompress_chunk(), and remove "chunkdata" from parameter list.
+  Put a call to png_check_chunk_name() in png_read_chunk_header().
+  Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte.
+  Removed two calls to png_check_chunk_name() occurring later in the process.
+  Define PNG_NO_ERROR_NUMBERS by default in pngconf.h
+
+Version 1.4.0beta25 [July 30, 2008]
+  Added a call to png_check_chunk_name() in pngpread.c
+  Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte.
+  Added png_push_have_buffer() function to pngpread.c
+  Eliminated PNG_BIG_ENDIAN_SUPPORTED and associated png_get_* macros.
+  Made inline expansion of png_get_*() optional with PNG_USE_READ_MACROS.
+  Eliminated all PNG_USELESS_TESTS and PNG_CORRECT_PALETTE_SUPPORTED code.
+  Synced contrib directory and configure files with libpng-1.2.30beta06.
+  Eliminated no-longer-used pngdefs.h (but it's still built in the makefiles)
+  Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c
+
+Version 1.4.0beta26 [August 4, 2008]
+  Removed png_push_have_buffer() function in pngpread.c.  It increased the
+    compiled library size slightly.
+  Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta)
+  Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings.
+  Updated contrib/visupng/cexcept.h to version 2.0.1
+  Added PNG_LITERAL_CHARACTER macros for #, [, and ].
+
+Version 1.4.0beta27 [August 5, 2008]
+  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
+  Moved newline character from individual png_debug messages into the
+    png_debug macros.
+  Allow user to #define their own png_debug, png_debug1, and png_debug2.
+
+Version 1.4.0beta28 [August 5, 2008]
+  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
+  Added PNG_STRING_NEWLINE macro
+
+Version 1.4.0beta29 [August 9, 2008]
+  Revised usage of PNG_STRING_NEWLINE to work on non-ISO compilers.
+  Added PNG_STRING_COPYRIGHT macro.
+  Added non-ISO versions of png_debug macros.
+
+Version 1.4.0beta30 [August 14, 2008]
+  Added premultiplied alpha feature (Volker Wiendl).
+
+Version 1.4.0beta31 [August 18, 2008]
+  Moved png_set_premultiply_alpha from pngtrans.c to pngrtran.c
+  Removed extra crc check at the end of png_handle_cHRM().  Bug introduced
+    in libpng-1.4.0beta20.
+
+Version 1.4.0beta32 [August 19, 2008]
+  Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call.
+  Revised PNG_NO_STDIO version of png_write_flush()
+
+Version 1.4.0beta33 [August 20, 2008]
+  Added png_get|set_chunk_cache_max() to limit the total number of sPLT,
+    text, and unknown chunks that can be stored.
+
+Version 1.4.0beta34 [September 6, 2008]
+  Shortened tIME_string to 29 bytes in pngtest.c
+  Fixed off-by-one error introduced in png_push_read_zTXt() function in
+    libpng-1.2.30beta04/pngpread.c (Harald van Dijk)
+
+Version 1.4.0beta35 [October 6, 2008]
+  Changed "trans_values" to "trans_color".
+  Changed so-number from 0 to 14.  Some OS do not like 0.
+  Revised makefile.darwin to fix shared library numbering.
+  Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
+    in example.c (debian bug report)
+
+Version 1.4.0beta36 [October 25, 2008]
+  Sync with tEXt vulnerability fix in libpng-1.2.33rc02.
+
+Version 1.4.0beta37 [November 13, 2008]
+  Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c,
+    and pngwrite.c
+
+Version 1.4.0beta38 [November 22, 2008]
+  Added check for zero-area RGB cHRM triangle in png_check_cHRM() and
+    png_check_cHRM_fixed().
+
+Version 1.4.0beta39 [November 23, 2008]
+  Revised png_warning() to write its message on standard output by default
+    when warning_fn is NULL.
+
+Version 1.4.0beta40 [November 24, 2008]
+  Eliminated png_check_cHRM().  Instead, always use png_check_cHRM_fixed().
+  In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant
+    check for all-zero coordinates that is detected by the triangle check.
+
+Version 1.4.0beta41 [November 26, 2008]
+  Fixed string vs pointer-to-string error in png_check_keyword().
+  Rearranged test expressions in png_check_cHRM_fixed() to avoid internal
+    overflows.
+  Added PNG_NO_CHECK_cHRM conditional.
+
+Version 1.4.0beta42, 43 [December 1, 2008]
+  Merge png_debug with version 1.2.34beta04.
+
+Version 1.4.0beta44 [December 6, 2008]
+  Removed redundant check for key==NULL before calling png_check_keyword()
+    to ensure that new_key gets initialized and removed extra warning
+    (Merge with version 1.2.34beta05 -- Arvan Pritchard).
+
+Version 1.4.0beta45 [December 9, 2008]
+  In png_write_png(), respect the placement of the filler bytes in an earlier
+    call to png_set_filler() (Jim Barry).
+
+Version 1.4.0beta46 [December 10, 2008]
+  Undid previous change and added PNG_TRANSFORM_STRIP_FILLER_BEFORE and
+    PNG_TRANSFORM_STRIP_FILLER_AFTER conditionals and deprecated
+    PNG_TRANSFORM_STRIP_FILLER (Jim Barry).
+
+Version 1.4.0beta47 [December 15, 2008]
+  Support for dithering was disabled by default, because it has never
+    been well tested and doesn't work very well.  The code has not
+    been removed, however, and can be enabled by building libpng with
+    PNG_READ_DITHER_SUPPORTED defined.
+
+Version 1.4.0beta48 [February 14, 2009]
+  Added new exported function png_calloc().
+  Combined several instances of png_malloc(); png_memset() into png_calloc().
+  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
+    but was never defined.
+
+Version 1.4.0beta49 [February 28, 2009]
+  Added png_fileno() macro to pngconf.h, used in pngwio.c
+  Corrected order of #ifdef's in png_debug definition in png.h
+  Fixed bug introduced in libpng-1.4.0beta48 with the memset arguments
+    for pcal_params.
+  Fixed order of #ifdef directives in the png_debug defines in png.h
+    (bug introduced in libpng-1.2.34/1.4.0beta29).
+  Revised comments in png_set_read_fn() and png_set_write_fn().
+
+Version 1.4.0beta50 [March 18, 2009]
+  Use png_calloc() instead of png_malloc() to allocate big_row_buf when
+    reading an interlaced file, to avoid a possible UMR.
+  Undid revision of PNG_NO_STDIO version of png_write_flush().  Users
+    having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined
+    or supply their own flush_fn() replacement.
+  Revised libpng*.txt and png.h documentation about use of png_write_flush()
+    and png_set_write_fn().
+  Removed fflush() from pngtest.c.
+  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
+
+Version 1.4.0beta51 [March 21, 2009]
+  Removed new png_fileno() macro from pngconf.h .
+
+Version 1.4.0beta52 [March 27, 2009]
+  Relocated png_do_chop() ahead of building gamma tables in pngrtran.c
+    This avoids building 16-bit gamma tables unnecessarily.
+  Removed fflush() from pngtest.c.
+  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
+  Added a section on differences between 1.0.x and 1.2.x to libpng.3/libpng.txt
+
+Version 1.4.0beta53 [April 1, 2009]
+  Removed some remaining MMX macros from pngpriv.h
+  Fixed potential memory leak of "new_name" in png_write_iCCP() (Ralph Giles)
+
+Version 1.4.0beta54 [April 13, 2009]
+  Added "ifndef PNG_SKIP_SETJMP_CHECK" block in pngconf.h to allow
+    application code writers to bypass the check for multiple inclusion
+    of setjmp.h when they know that it is safe to ignore the situation.
+  Eliminated internal use of setjmp() in pngread.c and pngwrite.c
+  Reordered ancillary chunks in pngtest.png to be the same as what
+    pngtest now produces, and made some cosmetic changes to pngtest output.
+  Eliminated deprecated png_read_init_3() and png_write_init_3() functions.
+
+Version 1.4.0beta55 [April 15, 2009]
+  Simplified error handling in pngread.c and pngwrite.c by putting
+    the new png_read_cleanup() and png_write_cleanup() functions inline.
+
+Version 1.4.0beta56 [April 25, 2009]
+  Renamed "user_chunk_data" to "my_user_chunk_data" in pngtest.c to suppress
+    "shadowed declaration" warning from gcc-4.3.3.
+  Renamed "gamma" to "png_gamma" in pngset.c to avoid "shadowed declaration"
+    warning about a global "gamma" variable in math.h on some platforms.
+
+Version 1.4.0beta57 [May 2, 2009]
+  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
+    but was never defined (again).
+  Rebuilt configure scripts with autoconf-2.63 instead of 2.62
+  Removed pngprefs.h and MMX from makefiles
+
+Version 1.4.0beta58 [May 14, 2009]
+  Changed pngw32.def to pngwin.def in makefile.mingw (typo was introduced
+    in beta57).
+  Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)
+
+Version 1.4.0beta59 [May 15, 2009]
+  Reformated sources in libpng style (3-space indentation, comment format)
+  Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
+  Added sections about the git repository and our coding style to the
+    documentation
+  Relocated misplaced #endif in pngwrite.c, sCAL chunk handler.
+
+Version 1.4.0beta60 [May 19, 2009]
+  Conditionally compile png_read_finish_row() which is not used by
+    progressive readers.
+  Added contrib/pngminim/preader to demonstrate building minimal progressive
+    decoder, based on contrib/gregbook with embedded libpng and zlib.
+
+Version 1.4.0beta61 [May 20, 2009]
+  In contrib/pngminim/*, renamed "makefile.std" to "makefile", since there
+    is only one makefile in those directories, and revised the README files
+    accordingly.
+  More reformatting of comments, mostly to capitalize sentences.
+
+Version 1.4.0beta62 [June 2, 2009]
+  Added "#define PNG_NO_WRITE_SWAP" to contrib/pngminim/encoder/pngusr.h
+    and "define PNG_NO_READ_SWAP" to decoder/pngusr.h and preader/pngusr.h
+  Reformatted several remaining "else statement" into two lines.
+  Added a section to the libpng documentation about using png_get_io_ptr()
+    in configure scripts to detect the presence of libpng.
+
+Version 1.4.0beta63 [June 15, 2009]
+  Revised libpng*.txt and libpng.3 to mention calling png_set_IHDR()
+    multiple times and to specify the sample order in the tRNS chunk,
+    because the ISO PNG specification has a typo in the tRNS table.
+  Changed several PNG_UNKNOWN_CHUNK_SUPPORTED to
+    PNG_HANDLE_AS_UNKNOWN_SUPPORTED, to make the png_set_keep mechanism
+    available for ignoring known chunks even when not saving unknown chunks.
+  Adopted preference for consistent use of "#ifdef" and "#ifndef" versus
+    "#if defined()" and "if !defined()" where possible.
+
+Version 1.4.0beta64 [June 24, 2009]
+  Eliminated PNG_LEGACY_SUPPORTED code.
+  Moved the various unknown chunk macro definitions outside of the
+    PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.
+
+Version 1.4.0beta65 [June 26, 2009]
+  Added a reference to the libpng license in each file.
+
+Version 1.4.0beta66 [June 27, 2009]
+  Refer to the libpng license instead of the libpng license in each file.
+
+Version 1.4.0beta67 [July 6, 2009]
+  Relocated INVERT_ALPHA within png_read_png() and png_write_png().
+  Added high-level API transform PNG_TRANSFORM_GRAY_TO_RGB.
+  Added an "xcode" project to the projects directory (Alam Arias).
+
+Version 1.4.0beta68 [July 19, 2009]
+  Avoid some tests in filter selection in pngwutil.c
+
+Version 1.4.0beta69 [July 25, 2009]
+  Simplified the new filter-selection test.  This runs faster in the
+    common "PNG_ALL_FILTERS" and PNG_FILTER_NONE cases.
+  Removed extraneous declaration from the new call to png_read_gray_to_rgb()
+    (bug introduced in libpng-1.4.0beta67).
+  Fixed up xcode project (Alam Arias)
+  Added a prototype for png_64bit_product() in png.c
+
+Version 1.4.0beta70 [July 27, 2009]
+  Avoid a possible NULL dereference in debug build, in png_set_text_2().
+    (bug introduced in libpng-0.95, discovered by Evan Rouault)
+
+Version 1.4.0beta71 [July 29, 2009]
+  Rebuilt configure scripts with autoconf-2.64.
+
+Version 1.4.0beta72 [August 1, 2009]
+  Replaced *.tar.lzma with *.tar.xz in distribution.  Get the xz codec
+    from <http://tukaani.org/xz>.
+
+Version 1.4.0beta73 [August 1, 2009]
+  Reject attempt to write iCCP chunk with negative embedded profile length
+    (JD Chen) (CVE-2009-5063).
+
+Version 1.4.0beta74 [August 8, 2009]
+  Changed png_ptr and info_ptr member "trans" to "trans_alpha".
+
+Version 1.4.0beta75 [August 21, 2009]
+  Removed an extra png_debug() recently added to png_write_find_filter().
+  Fixed incorrect #ifdef in pngset.c regarding unknown chunk support.
+
+Version 1.4.0beta76 [August 22, 2009]
+  Moved an incorrectly located test in png_read_row() in pngread.c
+
+Version 1.4.0beta77 [August 27, 2009]
+  Removed lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt,
+    and the "noconfig" files from the distribution.
+  Moved CMakeLists.txt from scripts into the main libpng directory.
+  Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)
+
+Version 1.4.0beta78 [August 31, 2009]
+  Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h
+  Eliminated PNG_NO_FREE_ME and PNG_FREE_ME_SUPPORTED macros.
+  Use png_malloc plus a loop instead of png_calloc() to initialize
+    row_pointers in png_read_png().
+
+Version 1.4.0beta79 [September 1, 2009]
+  Eliminated PNG_GLOBAL_ARRAYS and PNG_LOCAL_ARRAYS; always use local arrays.
+  Eliminated PNG_CALLOC_SUPPORTED macro and always provide png_calloc().
+
+Version 1.4.0beta80 [September 17, 2009]
+  Removed scripts/libpng.icc
+  Changed typecast of filler from png_byte to png_uint_16 in png_set_filler().
+    (Dennis Gustafsson)
+  Fixed typo introduced in beta78 in pngtest.c ("#if def " should be "#ifdef ")
+
+Version 1.4.0beta81 [September 23, 2009]
+  Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h
+  Expanded TAB characters in pngrtran.c
+  Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid
+    compiler complaints about doubly declaring things "const".
+  Changed all "#if [!]defined(X)" to "if[n]def X" where possible.
+  Eliminated unused png_ptr->row_buf_size
+
+Version 1.4.0beta82 [September 25, 2009]
+  Moved redundant IHDR checking into new png_check_IHDR() in png.c
+    and report all errors found in the IHDR data.
+  Eliminated useless call to png_check_cHRM() from pngset.c
+
+Version 1.4.0beta83 [September 25, 2009]
+  Revised png_check_IHDR() to eliminate bogus complaint about filter_type.
+
+Version 1.4.0beta84 [September 30, 2009]
+  Fixed some inconsistent indentation in pngconf.h
+  Revised png_check_IHDR() to add a test for width variable less than 32-bit.
+
+Version 1.4.0beta85 [October 1, 2009]
+  Revised png_check_IHDR() again, to check info_ptr members instead of
+    the contents of the returned parameters.
+
+Version 1.4.0beta86 [October 9, 2009]
+  Updated the "xcode" project (Alam Arias).
+  Eliminated a shadowed declaration of "pp" in png_handle_sPLT().
+
+Version 1.4.0rc01 [October 19, 2009]
+  Trivial cosmetic changes.
+
+Version 1.4.0beta87 [October 30, 2009]
+  Moved version 1.4.0 back into beta.
+
+Version 1.4.0beta88 [October 30, 2009]
+  Revised libpng*.txt section about differences between 1.2.x and 1.4.0
+    because most of the new features have now been ported back to 1.2.41
+
+Version 1.4.0beta89 [November 1, 2009]
+  More bugfixes and improvements to CMakeLists.txt (Philip Lowman)
+  Removed a harmless extra png_set_invert_alpha() from pngwrite.c
+  Apply png_user_chunk_cache_max within png_decompress_chunk().
+  Merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate.
+
+Version 1.4.0beta90 [November 2, 2009]
+  Removed all remaining WIN32_WCE #ifdefs except those involving the
+    time.h "tm" structure
+
+Version 1.4.0beta91 [November 3, 2009]
+  Updated scripts/pngw32.def and projects/wince/png32ce.def
+  Copied projects/wince/png32ce.def to the scripts directory.
+  Added scripts/makefile.wce
+  Patched ltmain.sh for wince support.
+  Added PNG_CONVERT_tIME_SUPPORTED macro.
+
+Version 1.4.0beta92 [November 4, 2009]
+  Make inclusion of time.h in pngconf.h depend on PNG_CONVERT_tIME_SUPPORTED
+  Make #define PNG_CONVERT_tIME_SUPPORTED depend on PNG_WRITE_tIME_SUPPORTED
+  Revised libpng*.txt to describe differences from 1.2.40 to 1.4.0 (instead
+    of differences from 1.2.41 to 1.4.0)
+
+Version 1.4.0beta93 [November 7, 2009]
+  Added PNG_DEPSTRUCT, PNG_DEPRECATED, PNG_USE_RESULT, PNG_NORETURN, and
+    PNG_ALLOCATED macros to detect deprecated direct access to the
+    png_struct or info_struct members and other deprecated usage in
+    applications (John Bowler).
+  Updated scripts/makefile* to add "-DPNG_CONFIGURE_LIBPNG" to CFLAGS,
+    to prevent warnings about direct access to png structs by libpng
+    functions while building libpng.  They need to be tested, especially
+    those using compilers other than gcc.
+  Updated projects/visualc6 and visualc71 with "/d PNG_CONFIGURE_LIBPNG".
+    They should work but still need to be updated to remove
+    references to pnggccrd.c or pngvcrd.c and ASM building.
+  Added README.txt to the beos, cbuilder5, netware, and xcode projects warning
+    that they need to be updated, to remove references to pnggccrd.c and
+    pngvcrd.c and to depend on pngpriv.h
+  Removed three direct references to read_info_ptr members in pngtest.c
+    that were detected by the new PNG_DEPSTRUCT macro.
+  Moved the png_debug macro definitions and the png_read_destroy(),
+    png_write_destroy() and png_far_to_near() prototypes from png.h
+    to pngpriv.h (John Bowler)
+  Moved the synopsis lines for png_read_destroy(), png_write_destroy()
+    png_debug(), png_debug1(), and png_debug2() from libpng.3 to libpngpf.3.
+
+Version 1.4.0beta94 [November 9, 2009]
+  Removed the obsolete, unused pnggccrd.c and pngvcrd.c files.
+  Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions.
+  Removed dependency of pngtest.o on pngpriv.h in the makefiles.
+  Only #define PNG_DEPSTRUCT, etc. in pngconf.h if not already defined.
+
+Version 1.4.0beta95 [November 10, 2009]
+  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
+  Added -DPNG_CONFIGURE_LIBPNG to contrib/pngminm/*/makefile
+  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
+  Corrected the png_get_IHDR() call in contrib/gregbook/readpng2.c
+  Changed pngminim/*/gather.sh to stop trying to remove pnggccrd.c and pngvcrd.c
+  Added dependency on pngpriv.h in contrib/pngminim/*/makefile
+
+Version 1.4.0beta96 [November 12, 2009]
+  Renamed scripts/makefile.wce to scripts/makefile.cegcc
+  Revised Makefile.am to use libpng.sys while building libpng.so
+    so that only PNG_EXPORT functions are exported.
+  Removed the deprecated png_check_sig() function/macro.
+  Removed recently removed function names from scripts/*.def
+  Revised pngtest.png to put chunks in the same order written by pngtest
+    (evidently the same change made in libpng-1.0beta54 was lost).
+  Added PNG_PRIVATE macro definition in pngconf.h for possible future use.
+
+Version 1.4.0beta97 [November 13, 2009]
+  Restored pngtest.png to the libpng-1.4.0beta7 version.
+  Removed projects/beos and netware.txt; no one seems to be supporting them.
+  Revised Makefile.in
+
+Version 1.4.0beta98 [November 13, 2009]
+  Added the "xcode" project to zip distributions,
+  Fixed a typo in scripts/pngwin.def introduced in beta97.
+
+Version 1.4.0beta99 [November 14, 2009]
+  Moved libpng-config.in and libpng.pc-configure.in out of the scripts
+    directory, to libpng-config.in and libpng-pc.in, respectively, and
+    modified Makefile.am and configure.ac accordingly.  Now "configure"
+    needs nothing from the "scripts" directory.
+  Avoid redefining PNG_CONST in pngconf.h
+
+Version 1.4.0beta100 [November 14, 2009]
+  Removed ASM builds from projects/visualc6 and projects/visualc71
+  Removed scripts/makefile.nommx and makefile.vcawin32
+  Revised CMakeLists.txt to account for new location of libpng-config.in
+    and libpng-pc.in
+  Updated INSTALL to reflect removal and relocation of files.
+
+Version 1.4.0beta101 [November 14, 2009]
+  Restored the binary files (*.jpg, *.png, some project files) that were
+    accidentally deleted from the zip and 7z distributions when the xcode
+    project was added.
+
+Version 1.4.0beta102 [November 18, 2009]
+  Added libpng-config.in and libpng-pc.in to the zip and 7z distributions.
+  Fixed a typo in projects/visualc6/pngtest.dsp, introduced in beta100.
+  Moved descriptions of makefiles and other scripts out of INSTALL into
+    scripts/README.txt
+  Updated the copyright year in scripts/pngwin.rc from 2006 to 2009.
+
+Version 1.4.0beta103 [November 21, 2009]
+  Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt
+  Align row_buf on 16-byte boundary in memory.
+  Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call
+    to png_flush() after png_write_IEND().  See 1.4.0beta32, 1.4.0beta50
+    changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES.  Someone
+    needs this feature.
+  Make the 'png_jmpbuf' macro expand to a call that records the correct
+    longjmp function as well as returning a pointer to the setjmp
+    jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'.
+    (John Bowler)
+
+Version 1.4.0beta104 [November 22, 2009]
+  Removed png_longjmp_ptr from scripts/*.def and libpng.3
+  Rebuilt configure scripts with autoconf-2.65
+
+Version 1.4.0beta105 [November 25, 2009]
+  Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535()
+    to accomplish alpha premultiplication when
+    PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined.
+  Changed "/255" to "/255.0" in background calculations to make it clear
+    that the 255 is used as a double.
+
+Version 1.4.0beta106 [November 27, 2009]
+  Removed premultiplied alpha feature.
+
+Version 1.4.0beta107 [December 4, 2009]
+  Updated README
+  Added "#define PNG_NO_PEDANTIC_WARNINGS" in the libpng source files.
+  Removed "-DPNG_CONFIGURE_LIBPNG" from the makefiles and projects.
+  Revised scripts/makefile.netbsd, makefile.openbsd, and makefile.sco
+    to put png.h and pngconf.h in $prefix/include, like the other scripts,
+    instead of in $prefix/include/libpng.  Also revised makefile.sco
+    to put them in $prefix/include/libpng15 instead of in
+    $prefix/include/libpng/libpng15.
+
+Version 1.4.0beta108 [December 11, 2009]
+  Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile
+  Relocated png_do_chop() to its original position in pngrtran.c; the
+    change in version 1.2.41beta08 caused transparency to be handled wrong
+    in some 16-bit datastreams (Yusaku Sugai).
+
+Version 1.4.0beta109 [December 13, 2009]
+  Added "bit_depth" parameter to the private png_build_gamma_table() function.
+  Pass bit_depth=8 to png_build_gamma_table() when bit_depth is 16 but the
+    PNG_16_TO_8 transform has been set, to avoid unnecessary build of 16-bit
+    tables.
+
+Version 1.4.0rc02 [December 20, 2009]
+  Declared png_cleanup_needed "volatile" in pngread.c and pngwrite.c
+
+Version 1.4.0rc03 [December 22, 2009]
+  Renamed libpng-pc.in back to libpng.pc.in and revised CMakeLists.txt
+    (revising the change in 1.4.0beta99)
+
+Version 1.4.0rc04 [December 25, 2009]
+  Swapped PNG_UNKNOWN_CHUNKS_SUPPORTED and PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+    in pngset.c to be consistent with other changes in version 1.2.38.
+
+Version 1.4.0rc05 [December 25, 2009]
+  Changed "libpng-pc.in" to "libpng.pc.in" in configure.ac, configure, and
+    Makefile.in to be consistent with changes in libpng-1.4.0rc03
+
+Version 1.4.0rc06 [December 29, 2009]
+  Reverted the gamma_table changes from libpng-1.4.0beta109.
+  Fixed some indentation errors.
+
+Version 1.4.0rc07 [January 1, 2010]
+  Revised libpng*.txt and libpng.3 about 1.2.x->1.4.x differences.
+  Use png_calloc() instead of png_malloc(); png_memset() in pngrutil.c
+  Update copyright year to 2010.
+
+Version 1.4.0rc08 [January 2, 2010]
+  Avoid deprecated references to png_ptr-io_ptr and png_ptr->error_ptr
+    in pngtest.c
+
+Version 1.4.0 [January 3, 2010]
+  No changes.
+
+Version 1.4.1beta01 [January 8, 2010]
+  Updated CMakeLists.txt for consistent indentation and to avoid an
+    unclosed if-statement warning (Philip Lowman).
+  Revised Makefile.am and Makefile.in to remove references to Y2KINFO,
+    KNOWNBUG, and libpng.la (Robert Schwebel).
+  Revised the makefiles to install the same files and symbolic
+    links as configure, except for libpng.la and libpng14.la.
+  Make png_set|get_compression_buffer_size() available even when
+    PNG_WRITE_SUPPORTED is not enabled.
+  Revised Makefile.am and Makefile.in to simplify their maintenance.
+  Revised scripts/makefile.linux to install a link to libpng14.so.14.1
+
+Version 1.4.1beta02 [January 9, 2010]
+  Revised the rest of the makefiles to install a link to libpng14.so.14.1
+
+Version 1.4.1beta03 [January 10, 2010]
+  Removed png_set_premultiply_alpha() from scripts/*.def
+
+Version 1.4.1rc01 [January 16, 2010]
+  No changes.
+
+Version 1.4.1beta04 [January 23, 2010]
+  Revised png_decompress_chunk() to improve speed and memory usage when
+    decoding large chunks.
+  Added png_set|get_chunk_malloc_max() functions.
+
+Version 1.4.1beta05 [January 26, 2010]
+  Relocated "int k" declaration in pngtest.c to minimize its scope.
+
+Version 1.4.1beta06 [January 28, 2010]
+  Revised png_decompress_chunk() to use a two-pass method suggested by
+    John Bowler.
+
+Version 1.4.1beta07 [February 6, 2010]
+  Folded some long lines in the source files.
+  Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
+    and a PNG_USER_LIMITS_SUPPORTED flag.
+  Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as
+    png_ptr->png_user_chunk_malloc_max.
+  Revised png_push_save_buffer() to do fewer but larger png_malloc() calls.
+
+Version 1.4.1beta08 [February 6, 2010]
+  Minor cleanup and updating of dates and copyright year.
+
+Version 1.5.0beta01 [February 7, 2010]
+  Moved declaration of png_struct into private pngstruct.h and png_info
+    into pnginfo.h
+
+Version 1.4.1beta09 and 1.5.0beta02 [February 7, 2010]
+  Reverted to original png_push_save_buffer() code.
+
+Version 1.4.1beta10 and 1.5.0beta03 [February 8, 2010]
+  Return allocated "old_buffer" in png_push_save_buffer() before
+    calling png_error(), to avoid a potential memory leak.
+  Updated configure script to use SO number 15.
+
+Version 1.5.0beta04 [February 9, 2010]
+  Removed malformed "incomplete struct declaration" of png_info from png.h
+
+Version 1.5.0beta05 [February 12, 2010]
+  Removed PNG_DEPSTRUCT markup in pngstruct.h and pnginfo.h, and undid the
+    linewrapping that it entailed.
+  Revised comments in pngstruct.h and pnginfo.h and added pointers to
+    the libpng license.
+  Changed PNG_INTERNAL to PNG_EXPOSE_INTERNAL_STRUCTURES
+  Removed the cbuilder5 project, which has not been updated to 1.4.0.
+
+Version 1.4.1beta12 and 1.5.0beta06 [February 14, 2010]
+  Fixed type declaration of png_get_chunk_malloc_max() in pngget.c (Daisuke
+    Nishikawa)
+
+Version 1.5.0beta07 [omitted]
+
+Version 1.5.0beta08 [February 19, 2010]
+  Changed #ifdef PNG_NO_STDIO_SUPPORTED to #ifdef PNG_NO_CONSOLE_IO_SUPPORTED
+    wherever png_snprintf() is used to construct error and warning messages.
+  Noted in scripts/makefile.mingw that it expects to be run under MSYS.
+  Removed obsolete unused MMX-querying support from contrib/gregbook
+  Added exported png_longjmp() function.
+  Removed the AIX redefinition of jmpbuf in png.h
+  Added -D_ALLSOURCE in configure.ac, makefile.aix, and CMakeLists.txt
+    when building on AIX.
+
+Version 1.5.0beta09 [February 19, 2010]
+  Removed -D_ALLSOURCE from configure.ac, makefile.aix, and CMakeLists.txt.
+  Changed the name of png_ptr->jmpbuf to png_ptr->png_jmpbuf in pngstruct.h
+
+Version 1.5.0beta10 [February 25, 2010]
+  Removed unused gzio.c from contrib/pngminim gather and makefile scripts
+  Removed replacement error handlers from contrib/gregbook.  Because of
+    the new png_longjmp() function they are no longer needed.
+
+Version 1.5.0beta11 [March 6, 2010]
+  Removed checking for already-included setjmp.h from pngconf.h
+  Fixed inconsistent indentations and made numerous cosmetic changes.
+  Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5
+
+Version 1.5.0beta12 [March 9, 2010]
+  Moved "#include png.h" inside pngpriv.h and removed "#include png.h" from
+    the source files, along with "#define PNG_EXPOSE_INTERNAL_STRUCTURES"
+    and "#define PNG_NO_PEDANTIC_WARNINGS" (John Bowler).
+  Created new pngdebug.h and moved debug definitions there.
+
+Version 1.5.0beta13 [March 10, 2010]
+  Protect pngstruct.h, pnginfo.h, and pngdebug.h from being included twice.
+  Revise the "#ifdef" blocks in png_inflate() so it will compile when neither
+    PNG_USER_CHUNK_MALLOC_MAX nor PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+    is defined.
+  Removed unused png_measure_compressed_chunk() from pngpriv.h and libpngpf.3
+  Moved the 'config.h' support from pngconf.h to pngpriv.h
+  Removed PNGAPI from the png_longjmp_ptr typedef.
+  Eliminated dependence of pngtest.c on the private pngdebug.h file.
+  Make all png_debug macros into *unterminated* statements or
+    expressions (i.e. a trailing ';' must always be added) and correct
+    the format statements in various png_debug messages.
+
+Version 1.5.0beta14 [March 14, 2010]
+  Removed direct access to png_ptr->io_ptr from the Windows code in pngtest.c
+  Revised Makefile.am to account for recent additions and replacements.
+  Corrected CE and OS/2 DEF files (scripts/png*def) for symbols removed and
+    added ordinal numbers to the Windows DEF file and corrected the duplicated
+    ordinal numbers on CE symbols that are commented out.
+  Added back in export symbols that can be present in the Windows build but
+    are disabled by default.
+  PNG_EXPORT changed to include an 'ordinal' field for DEF file generation.
+    PNG_CALLBACK added to make callback definitions uniform.  PNGAPI split
+    into PNGCAPI (base C form), PNGAPI (exports) and PNGCBAPI (callbacks),
+    and appropriate changes made to all files.  Cygwin builds re-hinged to
+    allow procedure call standard changes and to remove the need for the DEF
+    file (fixes build on Cygwin).
+  Enabled 'attribute' warnings that are relevant to library APIs and callbacks.
+  Changed rules for generation of the various symbol files and added a new
+    rule for a DEF file (which is also added to the distribution).
+  Updated the symbol file generation to stop it adding spurious spaces
+    to EOL (coming from preprocessor macro expansion).  Added a facility
+    to join tokens in the output and rewrite *.dfn to use this.
+  Eliminated scripts/*.def in favor of libpng.def; updated projects/visualc71
+    and removed scripts/makefile.cygwin.
+  Made PNG_BUILD_DLL safe: it can be set whenever a DLL is being built.
+  Removed the include of sys/types.h - apparently unnecessary now on the
+    platforms on which it happened (all but Mac OS and RISC OS).
+  Moved the Mac OS test into pngpriv.h (the only place it is used.)
+
+Version 1.5.0beta15 [March 17, 2010]
+  Added symbols.chk target to Makefile.am to validate the symbols in png.h
+    against the new DEF file scripts/symbols.def.
+  Changed the default DEF file back to pngwin.def.
+  Removed makefile.mingw.
+  Eliminated PNG_NO_EXTERN and PNG_ALL_EXTERN
+
+Version 1.5.0beta16 [April 1, 2010]
+  Make png_text_struct independent of PNG_iTXt_SUPPORTED, so that
+    fields are initialized in all configurations.  The READ/WRITE
+    macros (PNG_(READ|WRITE)_iTXt_SUPPORTED) still function as
+    before to disable code to actually read or write iTXt chunks
+    and iTXt_SUPPORTED can be used to detect presence of either
+    read or write support (but it is probably better to check for
+    the one actually required - read or write.)
+  Combined multiple png_warning() calls for a single error.
+  Restored the macro definition of png_check_sig().
+
+Version 1.5.0beta17 [April 17, 2010]
+  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
+  Documented the fact that png_set_dither() was disabled since libpng-1.4.0.
+  Reenabled png_set_dither() but renamed it to png_set_quantize() to reflect
+    more accurately what it actually does.  At the same time, renamed
+    the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros to
+    PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS.
+  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
+  Freeze build-time only configuration in the build.
+    In all prior versions of libpng most configuration options
+    controlled by compiler #defines had to be repeated by the
+    application code that used libpng.  This patch changes this
+    so that compilation options that can only be changed at build
+    time are frozen in the build.  Options that are compiler
+    dependent (and those that are system dependent) are evaluated
+    each time - pngconf.h holds these.  Options that can be changed
+    per-file in the application are in png.h.  Frozen options are
+    in the new installed header file pnglibconf.h (John Bowler)
+  Removed the xcode project because it has not been updated to work
+    with libpng-1.5.0.
+  Removed the ability to include optional pngusr.h
+
+Version 1.5.0beta18 [April 17, 2010]
+  Restored the ability to include optional pngusr.h
+  Moved replacements for png_error() and png_warning() from the
+    contrib/pngminim project to pngerror.c, for use when warnings or
+    errors are disabled via PNG_NO_WARN or PNG_NO_ERROR_TEXT, to avoid
+    storing unneeded error/warning text.
+  Updated contrib/pngminim project to work with the new pnglibconf.h
+  Added some PNG_NO_* defines to contrib/pngminim/*/pngusr.h to save space.
+
+Version 1.5.0beta19 [April 24, 2010]
+  Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED.  This allows the functions
+    to read and write ints to be disabled independently of PNG_USE_READ_MACROS,
+    which allows libpng to be built with the functions even though the default
+    is to use the macros - this allows applications to choose at app build
+    time whether or not to use macros (previously impossible because the
+    functions weren't in the default build.)
+  Changed Windows calling convention back to __cdecl for API functions.
+    For Windows/x86 platforms only:
+      __stdcall is no longer needed for Visual Basic, so libpng-1.5.0 uses
+      __cdecl throughout (both API functions and callbacks) on Windows/x86
+      platforms.
+  Replaced visualc6 and visualc71 projects with new vstudio project
+  Relaxed the overly-restrictive permissions of some files.
+
+Version 1.5.0beta20 [April 24, 2010]
+  Relaxed more overly-restrictive permissions of some files.
+
+Version 1.5.0beta21 [April 27, 2010]
+  Removed some unwanted binary bytes and changed CRLF to NEWLINE in the new
+    vstudio project files, and some trivial editing of some files in the
+    scripts directory.
+  Set PNG_NO_READ_BGR, PNG_NO_IO_STATE, and PNG_NO_TIME_RFC1123 in
+    contrib/pngminim/decoder/pngusr.h to make a smaller decoder application.
+
+Version 1.5.0beta22 [April 28, 2010]
+  Fixed dependencies of GET_INT_32 - it does not require READ_INT_FUNCTIONS
+    because it has a macro equivalent.
+  Improved the options.awk script; added an "everything off" option.
+  Revised contrib/pngminim to use the "everything off" option in pngusr.dfa.
+
+Version 1.5.0beta23 [April 29, 2010]
+  Corrected PNG_REMOVED macro to take five arguments.
+    The macro was documented with two arguments (name,ordinal), however
+    the symbol checking .dfn files assumed five arguments.  The five
+    argument form seems more useful so it is changed to that.
+  Corrected PNG_UNKNOWN_CHUNKS_SUPPORTED to PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+    in gregbook/readpng2.c
+  Corrected protection of png_get_user_transform_ptr. The API declaration in
+    png.h is removed if both READ and WRITE USER_TRANSFORM are turned off
+    but was left defined in pngtrans.c
+  Added logunsupported=1 to cause pnglibconf.h to document disabled options.
+    This makes the installed pnglibconf.h more readable but causes no
+    other change.  The intention is that users of libpng will find it
+    easier to understand if an API they need is missing.
+  Include png_reset_zstream() in png.c only when PNG_READ_SUPPORTED is defined.
+  Removed dummy_inflate.c from contrib/pngminim/encoder
+  Removed contrib/pngminim/*/gather.sh; gathering is now done in the makefile.
+
+Version 1.5.0beta24 [May 7, 2010]
+  Use bitwise "&" instead of arithmetic mod in pngrutil.c calculation of the
+    offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf.
+  Added more blank lines for readability.
+
+Version 1.5.0beta25 [June 18, 2010]
+  In pngpread.c: png_push_have_row() add check for new_row > height
+  Removed the now-redundant check for out-of-bounds new_row from example.c
+
+Version 1.5.0beta26 [June 18, 2010]
+  In pngpread.c: png_push_process_row() add check for too many rows.
+
+Version 1.5.0beta27 [June 18, 2010]
+  Removed the check added in beta25 as it is now redundant.
+
+Version 1.5.0beta28 [June 20, 2010]
+  Rewrote png_process_IDAT_data to consistently treat extra data as warnings
+    and handle end conditions more cleanly.
+  Removed the new (beta26) check in png_push_process_row().
+
+Version 1.5.0beta29 [June 21, 2010]
+  Revised scripts/options.awk to work on Sunos (but still doesn't work)
+  Added comment to options.awk and contrib/pngminim/*/makefile to try nawk.
+
+Version 1.5.0beta30 [June 22, 2010]
+  Stop memory leak when reading a malformed sCAL chunk.
+
+Version 1.5.0beta31 [June 26, 2010]
+  Revised pngpread.c patch of beta28 to avoid an endless loop.
+  Removed some trailing blanks.
+
+Version 1.5.0beta32 [June 26, 2010]
+  Removed leftover scripts/options.patch and scripts/options.rej
+
+Version 1.5.0beta33 [July 6, 3010]
+  Made FIXED and FLOATING options consistent in the APIs they enable and
+    disable.  Corrected scripts/options.awk to handle both command line
+    options and options specified in the .dfa files.
+  Changed char *msg to PNG_CONST char *msg in pngrutil.c
+  Make png_set_sRGB_gAMA_and_cHRM set values using either the fixed or
+    floating point APIs, but not both.
+  Reversed patch to remove error handler when the jmp_buf is stored in the
+    main program structure, not the png_struct.
+    The error handler is needed because the default handler in libpng will
+    always use the jmp_buf in the library control structure; this is never
+    set.  The gregbook code is a useful example because, even though it
+    uses setjmp/longjmp, it shows how error handling can be implemented
+    using control mechanisms not directly supported by libpng.  The
+    technique will work correctly with mechanisms such as Microsoft
+    Structure Exceptions or C++ exceptions (compiler willing - note that gcc
+    does not by default support interworking of C and C++ error handling.)
+  Reverted changes to call png_longjmp in contrib/gregbook where it is not
+    appropriate.  If mainprog->jmpbuf is used by setjmp, then png_longjmp
+    cannot be used.
+  Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans)
+  Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {')
+
+Version 1.5.0beta34 [July 12, 2010]
+  Put #ifndef PNG_EXTERN, #endif around the define PNG_EXTERN in pngpriv.h
+
+Version 1.5.0beta35 [July 24, 2010]
+  Removed some newly-added TAB characters.
+  Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2
+  Moved the definition of png_snprintf() outside of the enclosing
+    #ifdef blocks in pngconf.h
+
+Version 1.5.0beta36 [July 29, 2010]
+  Patches by John Bowler:
+  Fixed point APIs are now supported throughout (no missing APIs).
+  Internal fixed point arithmetic support exists for all internal floating
+    point operations.
+  sCAL validates the floating point strings it is passed.
+  Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2
+  Two new APIs exist to get the number of passes without turning on the
+    PNG_INTERLACE transform and to get the number of rows in the current
+    pass.
+  A new test program, pngvalid.c, validates the gamma code.
+  Errors in the 16-bit gamma correction (overflows) have been corrected.
+  cHRM chunk testing is done consistently (previously the floating point
+    API bypassed it, because the test really didn't work on FP, now the test
+    is performed on the actual values to be stored in the PNG file so it
+    works in the FP case too.)
+  Most floating point APIs now simply call the fixed point APIs after
+    converting the values to the fixed point form used in the PNG file.
+  The standard headers no longer include zlib.h, which is currently only
+    required for pngstruct.h and can therefore be internal.
+  Revised png_get_int_32 to undo the PNG two's complement representation of
+    negative numbers.
+
+Version 1.5.0beta37 [July 30, 2010]
+  Added a typecast in png_get_int_32() in png.h and pngrutil.h to avoid
+    a compiler warning.
+  Replaced oFFs 0,0 with oFFs -10,20 in pngtest.png
+
+Version 1.5.0beta38 [July 31, 2010]
+  Implemented remaining "_fixed" functions.
+  Corrected a number of recently introduced warnings mostly resulting from
+    safe but uncast assignments to shorter integers.  Also added a zlib
+    VStudio release library project because the latest zlib Official Windows
+    build does not include such a thing.
+  Revised png_get_int_16() to be similar to png_get_int_32().
+  Restored projects/visualc71.
+
+Version 1.5.0beta39 [August 2, 2010]
+  VisualC/GCC warning fixes, VisualC build fixes
+  The changes include support for function attributes in VC in addition to
+    those already present in GCC - necessary because without these some
+    warnings are unavoidable.  Fixes include signed/unsigned fixes in
+    pngvalid and checks with gcc -Wall -Wextra -Wunused.
+  VC requires function attributes on function definitions as well as
+    declarations, PNG_FUNCTION has been added to enable this and the
+    relevant function definitions changed.
+
+Version 1.5.0beta40 [August 6, 2010]
+  Correct use of _WINDOWS_ in pngconf.h
+  Removed png_mem_ #defines; they are no longer used.
+  Added the sRGB chunk to pngtest.png
+
+Version 1.5.0beta41 [August 11, 2010]
+  Added the cHRM chunk to pngtest.png
+  Don't try to use version-script with cygwin/mingw.
+  Revised contrib/gregbook to work under cygwin/mingw.
+
+Version 1.5.0beta42 [August 18, 2010]
+  Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov)
+  Made all API functions that have const arguments and constant string
+    literal pointers declare them (John Bowler).
+
+Version 1.5.0beta43 [August 20, 2010]
+  Removed spurious tabs, shorten long lines (no source change)
+    Also added scripts/chkfmt to validate the format of all the files that can
+    reasonably be validated (it is suggested to run "make distclean" before
+    checking, because some machine generated files have long lines.)
+  Reformatted the CHANGES file to be more consistent throughout.
+  Made changes to address various issues identified by GCC, mostly
+    signed/unsigned and shortening problems on assignment but also a few
+    difficult to optimize (for GCC) loops.
+  Fixed non-GCC fixed point builds.  In png.c a declaration was misplaced
+    in an earlier update.  Fixed to declare the auto variables at the head.
+  Use cexcept.h in pngvalid.c.
+
+Version 1.5.0beta44 [August 24, 2010]
+  Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for
+    installing libpng in /usr/lib64 (Funda Wang).
+  Revised CMakeLists.txt to put the man pages in share/man/man* not man/man*
+  Revised CMakeLists.txt to make symlinks instead of copies when installing.
+  Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
+  Implemented memory checks within pngvalid
+  Reformatted/rearranged pngvalid.c to assist use of progressive reader.
+  Check interlaced images in pngvalid
+  Clarified pngusr.h comments in pnglibconf.dfa
+  Simplified the pngvalid error-handling code now that cexcept.h is in place.
+  Implemented progressive reader in pngvalid.c for standard tests
+  Implemented progressive read in pngvalid.c gamma tests
+  Turn on progressive reader in pngvalid.c by default and tidy code.
+
+Version 1.5.0beta45 [August 26, 2010]
+  Added an explicit make step to projects/vstudio for pnglibconf.h
+    Also corrected zlib.vcxproj into which Visual Studio had introduced
+    what it calls an "authoring error".  The change to make pnglibconf.h
+    simply copies the file; in the future it may actually generate the
+    file from scripts/pnglibconf.dfa as the other build systems do.
+  Changed pngvalid to work when floating point APIs are disabled
+  Renamed the prebuilt scripts/pnglibconf.h to scripts/pnglibconf.h.prebuilt
+  Supply default values for PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX
+    in pngpriv.h in case the user neglected to define them in their pngusr.h
+
+Version 1.5.0beta46 [August 28, 2010]
+  Added new private header files to libpng_sources in CMakeLists.txt
+  Added PNG_READ_16BIT, PNG_WRITE_16BIT, and PNG_16BIT options.
+  Added reference to scripts/pnglibconf.h.prebuilt in the visualc71 project.
+
+Version 1.5.0beta47 [September 11, 2010]
+  Fixed a number of problems with 64-bit compilation reported by Visual
+    Studio 2010 (John Bowler).
+
+Version 1.5.0beta48 [October 4, 2010]
+  Updated CMakeLists.txt (Philip Lowman).
+  Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
+    $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
+  Fixed problem with symbols creation in Makefile.am which was assuming that
+    all versions of ccp write to standard output by default (Martin Banky). The
+    bug was introduced in libpng-1.2.9beta5.
+  Removed unused mkinstalldirs.
+
+Version 1.5.0beta49 [October 8, 2010]
+  Undid Makefile.am revision of 1.5.0beta48.
+
+Version 1.5.0beta50 [October 14, 2010]
+  Revised Makefile.in to account for mkinstalldirs being removed.
+  Added some "(unsigned long)" typecasts in printf statements in pngvalid.c.
+  Suppressed a compiler warning in png_handle_sPLT().
+  Check for out-of-range text compression mode in png_set_text().
+
+Version 1.5.0beta51 [October 15, 2010]
+  Changed embedded dates to "(PENDING RELEASE) in beta releases (and future
+    rc releases) to minimize the difference between releases.
+
+Version 1.5.0beta52 [October 16, 2010]
+  Restored some of the embedded dates (in png.h, png.c, documentation, etc.)
+
+Version 1.5.0beta53 [October 18, 2010]
+  Updated INSTALL to mention using "make maintainer-clean" and to remove
+    obsolete statement about a custom ltmain.sh
+  Disabled "color-tests" by default in Makefile.am so it will work with
+    automake versions earlier than 1.11.1
+  Use document name "libpng-manual.txt" instead of "libpng-<version>.txt"
+    to simplify version differences.
+  Removed obsolete remarks about setjmp handling from INSTALL.
+  Revised and renamed the typedef in png.h and png.c that was designed
+    to catch library and header mismatch.
+
+Version 1.5.0beta54 [November 10, 2010]
+  Require 48 bytes, not 64 bytes, for big_row_buf in overflow checks.
+  Used a consistent structure for the pngget.c functions.
+
+Version 1.5.0beta55 [November 21, 2010]
+  Revised png_get_uint_32, png_get_int_32, png_get_uint_16 (Cosmin)
+  Moved reading of file signature into png_read_sig (Cosmin)
+  Fixed atomicity of chunk header serialization (Cosmin)
+  Added test for io_state in pngtest.c (Cosmin)
+  Added "#!/bin/sh" at the top of contrib/pngminim/*/gather.sh scripts.
+  Changes to remove gcc warnings (John Bowler)
+    Certain optional gcc warning flags resulted in warnings in libpng code.
+    With these changes only -Wconversion and -Wcast-qual cannot be turned on.
+    Changes are trivial rearrangements of code.  -Wconversion is not possible
+    for pngrutil.c (because of the widespread use of += et al on variables
+    smaller than (int) or (unsigned int)) and -Wcast-qual is not possible
+    with pngwio.c and pngwutil.c because the 'write' callback and zlib
+    compression both fail to declare their input buffers with 'const'.
+
+Version 1.5.0beta56 [December 7, 2010]
+  Added the private PNG_UNUSED() macro definition in pngpriv.h.
+  Added some commentary about PNG_EXPORT in png.h and pngconf.h
+  Revised PNG_EXPORT() macro and added PNG_EXPORTA() macro, with the
+    objective of simplifying and improving the cosmetic appearance of png.h.
+  Fixed some incorrect "=" macro names in pnglibconf.dfa
+  Included documentation of changes in 1.5.0 from 1.4.x in libpng-manual.txt
+
+Version 1.5.0beta57 [December 9, 2010]
+  Documented the pngvalid gamma error summary with additional comments and
+    print statements.
+  Improved missing symbol handling in checksym.awk; symbols missing in both
+    the old and new files can now be optionally ignored, treated as errors
+    or warnings.
+  Removed references to pngvcrd.c and pnggccrd.c from the vstudio project.
+  Updated "libpng14" to "libpng15" in the visualc71 project.
+  Enabled the strip16 tests in pngvalid.`
+  Don't display test results (except PASS/FAIL) when running "make test".
+    Instead put them in pngtest-log.txt
+  Added "--with-zprefix=<string>" to configure.ac
+  Updated the prebuilt configuration files to autoconf version 2.68
+
+Version 1.5.0beta58 [December 19, 2010]
+  Fixed interlace image handling and add test cases (John Bowler)
+  Fixed the clean rule in Makefile.am to remove pngtest-log.txt
+  Made minor changes to work around warnings in gcc 3.4
+
+Version 1.5.0rc01 [December 27, 2010]
+  No changes.
+
+Version 1.5.0rc02 [December 27, 2010]
+  Eliminated references to the scripts/*.def files in project/visualc71.
+
+Version 1.5.0rc03 [December 28, 2010]
+  Eliminated scripts/*.def and revised Makefile.am accordingly
+
+Version 1.5.0rc04 [December 29, 2010]
+  Fixed bug in background transformation handling in pngrtran.c (it was
+    looking for the flag in png_ptr->transformations instead of in
+    png_ptr->flags) (David Raymond).
+
+Version 1.5.0rc05 [December 31, 2010]
+  Fixed typo in a comment in CMakeLists.txt (libpng14 => libpng15) (Cosmin)
+
+Version 1.5.0rc06 [January 4, 2011]
+  Changed the new configure option "zprefix=string" to "zlib-prefix=string"
+
+Version 1.5.0rc07 [January 4, 2011]
+  Updated copyright year.
+
+Version 1.5.0 [January 6, 2011]
+  No changes.
+
+version 1.5.1beta01 [January 8, 2011]
+  Added description of png_set_crc_action() to the manual.
+  Added a note in the manual that the type of the iCCP profile was changed
+    from png_charpp to png_bytepp in png_get_iCCP().  This change happened
+    in version 1.5.0beta36 but is not noted in the CHANGES.  Similarly,
+    it was changed from png_charpp to png_const_bytepp in png_set_iCCP().
+  Ensure that png_rgb_to_gray ignores palette mapped images, if libpng
+    internally happens to call it with one, and fixed a failure to handle
+    palette mapped images correctly.  This fixes CVE-2690.
+
+Version 1.5.1beta02 [January 14, 2011]
+  Fixed a bug in handling of interlaced images (bero at arklinux.org).
+  Updated CMakeLists.txt (Clifford Yapp)
+
+Version 1.5.1beta03 [January 14, 2011]
+  Fixed typecasting of some png_debug() statements (Cosmin)
+
+Version 1.5.1beta04 [January 16, 2011]
+  Updated documentation of png_set|get_tRNS() (Thomas Klausner).
+  Mentioned in the documentation that applications must #include "zlib.h"
+    if they need access to anything in zlib.h, and that a number of
+    macros such as png_memset() are no longer accessible by applications.
+  Corrected pngvalid gamma test "sample" function to access all of the color
+    samples of each pixel, instead of sampling the red channel three times.
+  Prefixed variable names index, div, exp, gamma with "png_" to avoid "shadow"
+    warnings, and (mistakenly) changed png_exp() to exp().
+
+Version 1.5.1beta05 [January 16, 2011]
+  Changed variable names png_index, png_div, png_exp, and png_gamma to
+    char_index, divisor, exp_b10, and gamma_val, respectively, and
+    changed exp() back to png_exp().
+
+Version 1.5.1beta06 [January 20, 2011]
+  Prevent png_push_crc_skip() from hanging while reading an unknown chunk
+    or an over-large compressed zTXt chunk with the progressive reader.
+  Eliminated more GCC "shadow" warnings.
+  Revised png_fixed() in png.c to avoid compiler warning about reaching the
+    end without returning anything.
+
+Version 1.5.1beta07 [January 22, 2011]
+  In the manual, describe the png_get_IHDR() arguments in the correct order.
+  Added const_png_structp and const_png_infop types, and used them in
+    prototypes for most png_get_*() functions.
+
+Version 1.5.1beta08 [January 23, 2011]
+  Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name()
+  Added synopses for the IO_STATE functions and other missing synopses
+    to the manual. Removed the synopses from libpngpf.3 because they
+    were out of date and no longer useful.  Better information can be
+    obtained by reading the prototypes and comments in pngpriv.h
+  Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build
+    Added a make macro DFNCPP that is a CPP that will accept the tokens in
+    a .dfn file and adds configure stuff to test for such a CPP.  ./configure
+    should fail if one is not available.
+  Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace.
+  Added png_get_current_row_number and png_get_current_pass_number for the
+    benefit of the user transform callback.
+  Added png_process_data_pause and png_process_data_skip for the benefit of
+    progressive readers that need to stop data processing or want to optimize
+    skipping of unread data (e.g., if the reader marks a chunk to be skipped.)
+
+Version 1.5.1beta09 [January 24, 2011]
+  Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error.
+    pngvalid contains tests of transforms, which tests are currently disabled
+    because they are incompletely tested.  gray_to_rgb was failing to expand
+    the bit depth for smaller bit depth images; this seems to be a long
+    standing error and resulted, apparently, in invalid output
+    (CVE-2011-0408, CERT VU#643140).  The documentation did not accurately
+    describe what libpng really does when converting RGB to gray.
+
+Version 1.5.1beta10 [January 27, 2010]
+  Fixed incorrect examples of callback prototypes in the manual, that were
+    introduced in libpng-1.0.0.
+  In addition the order of the png_get_uint macros with respect to the
+    relevant function definitions has been reversed.  This helps the
+    preprocessing of the symbol files be more robust.  Furthermore, the
+    symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when
+    the library may actually be built with PNG_USE_READ_MACROS; this stops
+    the read macros interfering with the symbol file format.
+  Made the manual, synopses, and function prototypes use the function
+    argument names file_gamma, int_file_gamma, and srgb_intent consistently.
+
+Version 1.5.1beta11 [January 28, 2011]
+  Changed PNG_UNUSED from "param=param;" to "{if(param){}}".
+  Corrected local variable type in new API png_process_data_skip()
+    The type was self-evidently incorrect but only causes problems on 64-bit
+    architectures.
+  Added transform tests to pngvalid and simplified the arguments.
+
+Version 1.5.1rc01 [January 29, 2011]
+  No changes.
+
+Version 1.5.1rc02 [January 31, 2011]
+  Added a request in the manual that applications do not use "png_" or
+    "PNG_" to begin any of their own symbols.
+  Changed PNG_UNUSED to "(void)param;" and updated the commentary in pngpriv.h
+
+Version 1.5.1 [February 3, 2011]
+  No changes.
+
+Version 1.5.2beta01 [February 13, 2011]
+  More -Wshadow fixes for older gcc compilers.  Older gcc versions apparently
+    check formal parameters names in function declarations (as well as
+    definitions) to see if they match a name in the global namespace.
+  Revised PNG_EXPORTA macro to not use an empty parameter, to accommodate the
+    old VisualC++ preprocessor.
+  Turned on interlace handling in png_read_png().
+  Fixed gcc pedantic warnings.
+  Handle longjmp in Cygwin.
+  Fixed png_get_current_row_number() in the interlaced case.
+  Cleaned up ALPHA flags and transformations.
+  Implemented expansion to 16 bits.
+
+Version 1.5.2beta02 [February 19, 2011]
+  Fixed mistake in the descriptions of user read_transform and write_transform
+    function prototypes in the manual.  The row_info struct is png_row_infop.
+  Reverted png_get_current_row_number() to previous (1.5.2beta01) behavior.
+  Corrected png_get_current_row_number documentation
+  Fixed the read/write row callback documentation.
+    This documents the current behavior, where the callback is called after
+    every row with information pertaining to the next row.
+
+Version 1.5.2beta03 [March 3, 2011]
+  Fixed scripts/makefile.vcwin32
+  Updated contrib/pngsuite/README to add the word "modify".
+  Define PNG_ALLOCATED to blank when _MSC_VER<1300.
+
+Version 1.5.2rc01 [March 19, 2011]
+  Define remaining attributes to blank when MSC_VER<1300.
+  ifdef out mask arrays in pngread.c when interlacing is not supported.
+
+Version 1.5.2rc02 [March 22, 2011]
+  Added a hint to try CPP=/bin/cpp if "cpp -E" fails in scripts/pnglibconf.mak
+    and in contrib/pngminim/*/makefile, eg., on SunOS 5.10, and removed "strip"
+    from the makefiles.
+  Fixed a bug (present since libpng-1.0.7) that makes png_handle_sPLT() fail
+    to compile when PNG_NO_POINTER_INDEXING is defined (Chubanov Kirill)
+
+Version 1.5.2rc03 [March 24, 2011]
+  Don't include standard header files in png.h while building the symbol table,
+    to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro).
+
+Version 1.5.2 [March 31, 2011]
+  No changes.
+
+Version 1.5.3beta01 [April 1, 2011]
+  Re-initialize the zlib compressor before compressing non-IDAT chunks.
+  Added API functions (png_set_text_compression_level() and four others) to
+    set parameters for zlib compression of non-IDAT chunks.
+
+Version 1.5.3beta02 [April 3, 2011]
+  Updated scripts/symbols.def with new API functions.
+  Only compile the new zlib re-initializing code when text or iCCP is
+    supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro.
+  Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
+  Optimize the zlib CMF byte in non-IDAT compressed chunks
+
+Version 1.5.3beta03 [April 16, 2011]
+  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
+    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
+    than __STDC__ (John Bowler).
+  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
+    the compiler that a user supplied callback (the error handler) does not
+    return, yet there is no guarantee in practice that the application code
+    will correctly implement the error handler because the compiler only
+    issues a warning if there is a mistake (John Bowler).
+  Removed the no-longer-used PNG_DEPSTRUCT macro.
+  Updated the zlib version to 1.2.5 in the VStudio project.
+  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
+    pngwutil.c (John Bowler).
+  Fixed bug with stripping the filler or alpha channel when writing, that
+    was introduced in libpng-1.5.2beta01 (bug report by Andrew Church).
+
+Version 1.5.3beta04 [April 27, 2011]
+  Updated pngtest.png with the new zlib CMF optimization.
+  Cleaned up conditional compilation code and of background/gamma handling
+    Internal changes only except a new option to avoid compiling the
+    png_build_grayscale_palette API (which is not used at all internally.)
+    The main change is to move the transform tests (READ_TRANSFORMS,
+    WRITE_TRANSFORMS) up one level to the caller of the APIs.  This avoids
+    calls to spurious functions if all transforms are disabled and slightly
+    simplifies those functions.  Pngvalid modified to handle this.
+    A minor change is to stop the strip_16 and expand_16 interfaces from
+    disabling each other; this allows the future alpha premultiplication
+    code to use 16-bit intermediate values while still producing 8-bit output.
+    png_do_background and png_do_gamma have been simplified to take a single
+    pointer to the png_struct rather than pointers to every item required
+    from the png_struct. This makes no practical difference to the internal
+    code.
+  A serious bug in the pngvalid internal routine 'standard_display_init' has
+    been fixed - this failed to initialize the red channel and accidentally
+    initialized the alpha channel twice.
+  Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
+    avoid a possible clash with the png_jmpbuf macro on some platforms.
+
+Version 1.5.3beta05 [May 6, 2011]
+  Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the
+    correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and
+    pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs.
+  Removed png_snprintf and added formatted warning messages.  This change adds
+    internal APIs to allow png_warning messages to have parameters without
+    requiring the host OS to implement snprintf.  As a side effect the
+    dependency of the tIME-supporting RFC1132 code on stdio is removed and
+    PNG_NO_WARNINGS does actually work now.
+  Pass "" instead of '\0' to png_default_error() in png_err().  This mistake
+    was introduced in libpng-1.2.20beta01.  This fixes CVE-2011-2691.
+  Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
+    optimization configurable.
+  IDAT compression failed if preceded by a compressed text chunk (bug
+    introduced in libpng-1.5.3beta01-02).  This was because the attempt to
+    reset the zlib stream in png_write_IDAT happened after the first IDAT
+    chunk had been deflated - much too late.  In this change internal
+    functions were added to claim/release the z_stream and, hopefully, make
+    the code more robust.  Also deflateEnd checking is added - previously
+    libpng would ignore an error at the end of the stream.
+
+Version 1.5.3beta06 [May 8, 2011]
+  Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
+  Implemented premultiplied alpha support: png_set_alpha_mode API
+
+Version 1.5.3beta07 [May 11, 2011]
+  Added expand_16 support to the high level interface.
+  Added named value and 'flag' gamma support to png_set_gamma.  Made a minor
+    change from the previous (unreleased) ABI/API to hide the exact value used
+    for Macs - it's not a good idea to embed this in the ABI!
+  Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
+    from pngpriv.h to png.h because they must be visible to applications
+    that call png_set_unknown_chunks().
+  Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
+    before IDAT.
+
+Version 1.5.3beta08 [May 16, 2011]
+  Improved "pngvalid --speed" to exclude more of pngvalid from the time.
+  Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
+  The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
+    parameters are supplied by the caller), while in the absence of cHRM
+    sRGB/Rec 709 values are still used.  This introduced a divide-by-zero
+    bug in png_handle_cHRM().
+  The bKGD chunk no longer overwrites the background value set by
+    png_set_background(), allowing the latter to be used before the file
+    header is read. It never performed any useful function to override
+    the default anyway.
+  Added memory overwrite and palette image checks to pngvalid.c
+    Previously palette image code was poorly checked. Since the transformation
+    code has a special palette path in most cases this was a severe weakness.
+  Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
+    expanding an indexed image, always expand to RGBA if transparency is
+    present.
+
+Version 1.5.3beta09 [May 17, 2011]
+  Reversed earlier 1.5.3 change of transformation order; move png_expand_16
+    back where it was.  The change doesn't work because it requires 16-bit
+    gamma tables when the code only generates 8-bit ones.  This fails
+    silently; the libpng code just doesn't do any gamma correction.  Moving
+    the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
+    these are clearly better than none!
+
+Version 1.5.3beta10 [May 20, 2011]
+
+  png_set_background() and png_expand_16() did not work together correctly.
+    This problem is present in 1.5.2; if png_set_background is called with
+    need_expand false and the matching 16 bit color libpng erroneously just
+    treats it as an 8-bit color because of where png_do_expand_16 is in the
+    transform list.  This simple fix reduces the supplied colour to 8-bits,
+    so it gets smashed, but this is better than the current behavior.
+  Added tests for expand16, more fixes for palette image tests to pngvalid.
+    Corrects the code for palette image tests and disables attempts to
+    validate palette colors.
+
+Version 1.5.3rc01 [June 3, 2011]
+  No changes.
+
+Version 1.5.3rc02 [June 8, 2011]
+  Fixed uninitialized memory read in png_format_buffer() (Bug report by
+    Frank Busse, CVE-2011-2501, related to CVE-2004-0421).
+
+Version 1.5.3beta11 [June 11, 2011]
+  Fixed png_handle_sCAL which is broken in 1.5. This fixes CVE 2011-2692.
+  Added sCAL to pngtest.png
+  Revised documentation about png_set_user_limits() to say that it also affects
+    png writing.
+  Revised handling of png_set_user_limits() so that it can increase the
+    limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
+    reduce it.
+  Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
+    wrong (high by one) 25% of the time. Dividing by 257 with rounding is
+    wrong in 128 out of 65536 cases. Getting the right answer all the time
+    without division is easy.
+  Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
+  Added projects/owatcom, an IDE project for OpenWatcom to replace
+    scripts/makefile.watcom.  This project works with OpenWatcom 1.9. The
+    IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
+    The project is configurable, unlike the Visual Studio project, so long
+    as the developer has an awk.
+  Changed png_set_gAMA to limit the gamma value range so that the inverse
+    of the stored value cannot overflow the fixed point representation,
+    and changed other things OpenWatcom warns about.
+  Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
+    pngvalid to build when ALPHA_MODE is not supported, which is required if
+    it is to build on libpng 1.4.
+  Removed string/memory macros that are no longer used and are not
+    necessarily fully supportable, particularly png_strncpy and png_snprintf.
+  Added log option to pngvalid.c and attempted to improve gamma messages.
+
+Version 1.5.3 [omitted]
+  People found the presence of a beta release following an rc release
+    to be confusing; therefore we bump the version to libpng-1.5.4beta01
+    and there will be no libpng-1.5.3 release.
+
+Version 1.5.4beta01 [June 14, 2011]
+  Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+    to get the same (inaccurate) output as libpng-1.5.2 and earlier.
+  Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
+    outside of an unknown-chunk block in png.h because they are also
+    needed for other uses.
+
+Version 1.5.4beta02 [June 14, 2011]
+  Fixed and clarified LEGACY 16-to-8 scaling code.
+  Added png_set_chop_16() API, to match inaccurate results from previous
+    libpng versions.
+  Removed the ACCURATE and LEGACY options (they are no longer useable)
+  Use the old scaling method for background if png_set_chop_16() was
+    called.
+  Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED
+
+Version 1.5.4beta03 [June 15, 2011]
+  Fixed a problem in png_do_expand_palette() exposed by optimization in
+    1.5.3beta06
+  Also removed a spurious and confusing "trans" member ("trans") from png_info.
+  The palette expand optimization prevented expansion to an intermediate RGBA
+    form if tRNS was present but alpha was marked to be stripped; this exposed
+    a check for tRNS in png_do_expand_palette() which is inconsistent with the
+    code elsewhere in libpng.
+  Correction to the expand_16 code; removed extra instance of
+    png_set_scale_16_to_8 from pngpriv.h
+
+Version 1.5.4beta04 [June 16, 2011]
+  Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
+  Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
+  Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again.  If this is
+    not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
+  Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8
+
+Version 1.5.4beta05 [June 16, 2011]
+  Renamed png_set_strip_16() to png_set_scale_16() and renamed
+    png_set_chop_16() to png_set_strip(16) in an attempt to minimize the
+    behavior changes between libpng14 and libpng15.
+
+Version 1.5.4beta06 [June 18, 2011]
+  Fixed new bug that was causing both strip_16 and scale_16 to be applied.
+
+Version 1.5.4beta07 [June 19, 2011]
+  Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
+    The ACCURATE scale macro is no longer defined in 1.5 - call the
+    png_scale_16_to_8 API.  Made sure that PNG_READ_16_TO_8 is still defined
+    if the png_strip_16_to_8 API is present.  png_check_fp_number now
+    maintains some state so that positive, negative and zero values are
+    identified.  sCAL uses these to be strictly spec conformant.
+
+Version 1.5.4beta08 [June 23, 2011]
+  Fixed pngvalid if ACCURATE_SCALE is defined.
+  Updated scripts/pnglibconf.h.prebuilt.
+
+Version 1.5.4rc01 [June 30, 2011]
+  Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.
+
+Version 1.5.4 [July 7, 2011]
+  No changes.
+
+Version 1.5.5beta01 [July 13, 2011]
+  Fixed some typos and made other minor changes in the manual.
+  Updated contrib/pngminus/makefile.std (Samuli Souminen)
+
+Version 1.5.5beta02 [July 14, 2011]
+  Revised Makefile.am and Makefile.in to look in the right directory for
+    pnglibconf.h.prebuilt
+
+Version 1.5.5beta03 [July 27, 2011]
+  Enabled compilation with g++ compiler.  This compiler does not recognize
+    the file extension, so it always compiles with C++ rules.  Made minor
+    changes to pngrutil.c to cast results where C++ expects it but C does not.
+  Minor editing of libpng.3 and libpng-manual.txt.
+
+Version 1.5.5beta04 [July 29, 2011]
+  Revised CMakeLists.txt (Clifford Yapp)
+  Updated commentary about the png_rgb_to_gray() default coefficients
+    in the manual and in pngrtran.c
+
+Version 1.5.5beta05 [August 17, 2011]
+  Prevent unexpected API exports from non-libpng DLLs on Windows.  The "_DLL"
+    is removed from the test of whether a DLL is being built (this erroneously
+    caused the libpng APIs to be marked as DLL exports in static builds under
+    Microsoft Visual Studio).  Almost all of the libpng building configuration
+    is moved from pngconf.h to pngpriv.h, but PNG_DLL_EXPORT remains in
+    pngconf.h, though, so that it is colocated with the import definition (it
+    is no longer used anywhere in the installed headers).  The VStudio project
+    definitions have been cleaned up: "_USRDLL" has been removed from the
+    static library builds (this was incorrect), and PNG_USE_DLL has been added
+    to pngvalid to test the functionality (pngtest does not supply it,
+    deliberately).  The spurious "_EXPORTS" has been removed from the
+    libpng build (all these errors were a result of copy/paste between project
+    configurations.)
+  Added new types and internal functions for CIE RGB end point handling to
+    pngpriv.h (functions yet to be implemented).
+
+Version 1.5.5beta06 [August 26, 2011]
+  Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set in CMakeLists.txt
+    (Clifford Yap)
+  Fixes to rgb_to_gray and cHRM XYZ APIs (John Bowler):
+    The rgb_to_gray code had errors when combined with gamma correction.
+    Some pixels were treated as true grey when they weren't and such pixels
+    and true grey ones were not gamma corrected (the original value of the
+    red component was used instead).  APIs to get and set cHRM using color
+    space end points have been added and the rgb_to_gray code that defaults
+    based on cHRM, and the divide-by-zero bug in png_handle_cHRM (CERT
+    VU#477046, CVE-2011-3328, introduced in 1.5.4) have been corrected.
+  A considerable number of tests has been added to pngvalid for the
+    rgb_to_gray transform.
+  Arithmetic errors in rgb_to_gray whereby the calculated gray value was
+    truncated to the bit depth rather than rounded have been fixed except in
+    the 8-bit non-gamma-corrected case (where consistency seems more important
+    than correctness.)  The code still has considerable inaccuracies in the
+    8-bit case because 8-bit linear arithmetic is used.
+
+Version 1.5.5beta07 [September 7, 2011]
+  Added "$(ARCH)" option to makefile.darwin
+  Added SunOS support to configure.ac and Makefile.am
+  Changed png_chunk_benign_error() to png_warning() in png.c, in
+    png_XYZ_from_xy_checked().
+
+Version 1.5.5beta08 [September 10, 2011]
+  Fixed 64-bit compilation errors (gcc). The errors fixed relate
+    to conditions where types that are 32 bits in the GCC 32-bit
+    world (uLong and png_size_t) become 64 bits in the 64-bit
+    world.  This produces potential truncation errors which the
+    compiler correctly flags.
+  Relocated new HAVE_SOLARIS_LD definition in configure.ac
+  Constant changes for 64-bit compatibility (removal of L suffixes). The
+    16-bit cases still use "L" as we don't have a 16-bit test system.
+
+Version 1.5.5rc01 [September 15, 2011]
+  Removed "L" suffixes in pngpriv.h
+
+Version 1.5.5 [September 22, 2011]
+  No changes.
+
+Version 1.5.6beta01 [September 22, 2011]
+  Fixed some 64-bit type conversion warnings in pngrtran.c
+  Moved row_info from png_struct to a local variable.
+  The various interlace mask arrays have been made into arrays of
+    bytes and made PNG_CONST and static (previously some arrays were
+    marked PNG_CONST and some weren't).
+  Additional checks have been added to the transform code to validate the
+    pixel depths after the transforms on both read and write.
+  Removed some redundant code from pngwrite.c, in png_destroy_write_struct().
+  Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4].
+    This removes the need to allocate temporary strings for chunk names on
+    the stack in the read/write code.  Unknown chunk handling still uses the
+    string form because this is exposed in the API.
+
+Version 1.5.6beta02 [September 26, 2011]
+  Added a note in the manual the png_read_update_info() must be called only
+    once with a particular info_ptr.
+  Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro.
+
+Version 1.5.6beta03 [September 28, 2011]
+  Revised test-pngtest.sh to report FAIL when pngtest fails.
+  Added "--strict" option to pngtest, to report FAIL when the failure is
+    only because the resulting valid files are different.
+  Revised CMakeLists.txt to work with mingw and removed some material from
+    CMakeLists.txt that is no longer useful in libpng-1.5.
+
+Version 1.5.6beta04 [October 5, 2011]
+  Fixed typo in Makefile.in and Makefile.am ("-M Wl" should be "-M -Wl")."
+
+Version 1.5.6beta05 [October 12, 2011]
+  Speed up png_combine_row() for interlaced images. This reduces the generality
+    of the code, allowing it to be optimized for Adam7 interlace.  The masks
+    passed to png_combine_row() are now generated internally, avoiding
+    some code duplication and localizing the interlace handling somewhat.
+  Align png_struct::row_buf - previously it was always unaligned, caused by
+    a bug in the code that attempted to align it; the code needs to subtract
+    one from the pointer to take account of the filter byte prepended to
+    each row.
+  Optimized png_combine_row() when rows are aligned. This gains a small
+    percentage for 16-bit and 32-bit pixels in the typical case where the
+    output row buffers are appropriately aligned. The optimization was not
+    previously possible because the png_struct buffer was always misaligned.
+  Fixed bug in png_write_chunk_header() debug print, introduced in 1.5.6beta01.
+
+Version 1.5.6beta06 [October 17, 2011]
+  Removed two redundant tests for uninitialized row.
+  Fixed a relatively harmless memory overwrite in compressed text writing
+    with a 1 byte zlib buffer.
+  Add ability to call png_read_update_info multiple times to pngvalid.c.
+  Fixes for multiple calls to png_read_update_info. These fixes attend to
+    most of the errors revealed in pngvalid, however doing the gamma work
+    twice results in inaccuracies that can't be easily fixed.  There is now
+    a warning in the code if this is going to happen.
+  Turned on multiple png_read_update_info in pngvalid transform tests.
+  Prevent libpng from overwriting unused bits at the end of the image when
+    it is not byte aligned, while reading. Prior to libpng-1.5.6 libpng would
+    overwrite the partial byte at the end of each row if the row width was not
+    an exact multiple of 8 bits and the image is not interlaced.
+
+Version 1.5.6beta07 [October 21, 2011]
+  Made png_ptr->prev_row an aligned pointer into png_ptr->big_prev_row
+    (Mans Rullgard).
+
+Version 1.5.6rc01 [October 26, 2011]
+  Changed misleading "Missing PLTE before cHRM" warning to "Out of place cHRM"
+
+Version 1.5.6rc02 [October 27, 2011]
+  Added LSR() macro to defend against buggy compilers that evaluate non-taken
+    code branches and complain about out-of-range shifts.
+
+Version 1.5.6rc03 [October 28, 2011]
+  Renamed the LSR() macro to PNG_LSR() and added PNG_LSL() macro.
+  Fixed compiler warnings with Intel and MSYS compilers. The logical shift
+    fix for Microsoft Visual C is required by other compilers, so this
+    enables that fix for all compilers when using compile-time constants.
+    Under MSYS 'byte' is a name declared in a system header file, so we
+    changed the name of a local variable to avoid the warnings that result.
+  Added #define PNG_ALIGN_TYPE PNG_ALIGN_NONE to contrib/pngminim/*/pngusr.h
+
+Version 1.5.6 [November 3, 2011]
+  No changes.
+
+Version 1.5.7beta01 [November 4, 2011]
+  Added support for ARM processor, when decoding all PNG up-filtered rows
+    and any other-filtered rows with 3 or 4 bytes per pixel (Mans Rullgard).
+  Fixed bug in pngvalid on early allocation failure; fixed type cast in
+    pngmem.c; pngvalid would attempt to call png_error() if the allocation
+    of a png_struct or png_info failed. This would probably have led to a
+    crash.  The pngmem.c implementation of png_malloc() included a cast
+    to png_size_t which would fail on large allocations on 16-bit systems.
+  Fix for the preprocessor of the Intel C compiler. The preprocessor
+    splits adjacent @ signs with a space; this changes the concatenation
+    token from @-@-@ to PNG_JOIN; that should work with all compiler
+    preprocessors.
+  Paeth filter speed improvements from work by Siarhei Siamashka. This
+    changes the 'Paeth' reconstruction function to improve the GCC code
+    generation on x86. The changes are only part of the suggested ones;
+    just the changes that definitely improve speed and remain simple.
+    The changes also slightly increase the clarity of the code.
+
+Version 1.5.7beta02 [November 11, 2011]
+  Check compression_type parameter in png_get_iCCP and remove spurious
+    casts. The compression_type parameter is always assigned to, so must
+    be non-NULL. The cast of the profile length potentially truncated the
+    value unnecessarily on a 16-bit int system, so the cast of the (byte)
+    compression type to (int) is specified by ANSI-C anyway.
+  Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left
+    the sBIT fields in the test pixel as 0, which resulted in a floating
+    point division by zero which was irrelevant but causes systems where
+    FP exceptions cause a crash. Added code to pngvalid to turn on FP
+    exceptions if the appropriate glibc support is there to ensure this is
+    tested in the future.
+  Updated scripts/pnglibconf.mak and scripts/makefile.std to handle the
+    new PNG_JOIN macro.
+  Added versioning to pnglibconf.h comments.
+  Simplified read/write API initial version; basic read/write tested on
+    a variety of images, limited documentation (in the header file.)
+  Installed more accurate linear to sRGB conversion tables. The slightly
+    modified tables reduce the number of 16-bit values that
+    convert to an off-by-one 8-bit value.  The "makesRGB.c" code that was used
+    to generate the tables is now in a contrib/sRGBtables sub-directory.
+
+Version 1.5.7beta03 [November 17, 2011]
+  Removed PNG_CONST from the sRGB table declarations in pngpriv.h and png.c
+  Added run-time detection of NEON support.
+  Added contrib/libtests; includes simplified API test and timing test and
+    a color conversion utility for rapid checking of failed 'pngstest' results.
+  Multiple transform bug fixes plus a work-round for double gamma correction.
+    libpng does not support more than one transform that requires linear data
+    at once - if this is tried typically the results is double gamma
+    correction. Since the simplified APIs can need rgb to gray combined with
+    a compose operation it is necessary to do one of these outside the main
+    libpng transform code. This check-in also contains fixes to various bugs
+    in the simplified APIs themselves and to some bugs in compose and rgb to
+    gray (on palette) itself.
+  Fixes for C++ compilation using g++ When libpng source is compiled
+    using g++. The compiler imposes C++ rules on the C source; thus it
+    is desirable to make the source work with either C or C++ rules
+    without throwing away useful error information.  This change adds
+    png_voidcast to allow C semantic (void*) cases or the corresponding
+    C++ static_cast operation, as appropriate.
+  Added --noexecstack to assembler file compilation. GCC does not set
+    this on assembler compilation, even though it does on C compilation.
+    This creates security issues if assembler code is enabled; the
+    work-around is to set it by default in the flags for $(CCAS)
+  Work around compilers that don't support declaration of const data. Some
+    compilers fault 'extern const' data declarations (because the data is
+    not initialized); this turns on const-ness only for compilers where
+    this is known to work.
+
+Version 1.5.7beta04 [November 17, 2011]
+  Since the gcc driver does not recognize the --noexecstack flag, we must
+    use the -Wa prefix to have it passed through to the assembler.
+    Also removed a duplicate setting of this flag.
+  Added files that were omitted from the libpng-1.5.7beta03 zip distribution.
+
+Version 1.5.7beta05 [November 25, 2011]
+  Removed "zTXt" from warning in generic chunk decompression function.
+  Validate time settings passed to png_set_tIME() and png_convert_to_rfc1123()
+    (Frank Busse). Note: This prevented CVE-2015-7981 from affecting
+    libpng-1.5.7 and later.
+  Added MINGW support to CMakeLists.txt
+  Reject invalid compression flag or method when reading the iTXt chunk.
+  Backed out 'simplified' API changes. The API seems too complex and there
+    is a lack of consensus or enthusiasm for the proposals.  The API also
+    reveals significant bugs inside libpng (double gamma correction and the
+    known bug of being unable to retrieve a corrected palette). It seems
+    better to wait until the bugs, at least, are corrected.
+  Moved pngvalid.c into contrib/libtests
+  Rebuilt Makefile.in, configure, etc., with autoconf-2.68
+
+Version 1.5.7rc01 [December 1, 2011]
+  Replaced an "#if" with "#ifdef" in pngrtran.c
+  Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else)
+
+Version 1.5.7rc02 [December 5, 2011]
+  Revised project files and contrib/pngvalid/pngvalid.c to account for
+    the relocation of pngvalid into contrib/libtests.
+  Revised pngconf.h to use " __declspec(restrict)" only when MSC_VER >= 1400,
+    as in libpng-1.5.4.
+  Put CRLF line endings in the owatcom project files.
+
+Version 1.5.7rc03 [December 7, 2011]
+  Updated CMakeLists.txt to account for the relocation of pngvalid.c
+
+Version 1.5.7 [December 15, 2011]
+  Minor fixes to pngvalid.c for gcc 4.6.2 compatibility to remove warnings
+    reported by earlier versions.
+  Fixed minor memset/sizeof errors in pngvalid.c.
+
+Version 1.6.0beta01 [December 15, 2011]
+  Removed machine-generated configure files from the GIT repository (they will
+    continue to appear in the tarball distributions and in the libpng15 and
+    earlier GIT branches).
+  Restored the new 'simplified' API, which was started in libpng-1.5.7beta02
+    but later deleted from libpng-1.5.7beta05.
+  Added example programs for the new 'simplified' API.
+  Added ANSI-C (C90) headers and require them, and take advantage of the
+    change. Also fixed some of the projects/* and contrib/* files that needed
+    updates for libpng16 and the move of pngvalid.c.
+    With this change the required ANSI-C header files are assumed to exist: the
+    implementation must provide float.h, limits.h, stdarg.h and stddef.h and
+    libpng relies on limits.h and stddef.h existing and behaving as defined
+    (the other two required headers aren't used).  Non-ANSI systems that don't
+    have stddef.h or limits.h will have to provide an appropriate fake
+    containing the relevant types and #defines.
+  Dropped support for 16-bit platforms. The use of FAR/far has been eliminated
+    and the definition of png_alloc_size_t is now controlled by a flag so
+    that 'small size_t' systems can select it if necessary.  Libpng 1.6 may
+    not currently work on such systems -- it seems likely that it will
+    ask 'malloc' for more than 65535 bytes with any image that has a
+    sufficiently large row size (rather than simply failing to read such
+    images).
+  New tools directory containing tools used to generate libpng code.
+  Fixed race conditions in parallel make builds. With higher degrees of
+    parallelism during 'make' the use of the same temporary file names such
+    as 'dfn*' can result in a race where a temporary file from one arm of the
+    build is deleted or overwritten in another arm.  This changes the
+    temporary files for suffix rules to always use $* and ensures that the
+    non-suffix rules use unique file names.
+
+Version 1.6.0beta02 [December 21, 2011]
+  Correct configure builds where build and source directories are separate.
+    The include path of 'config.h' was erroneously made relative in pngvalid.c
+    in libpng 1.5.7.
+
+Version 1.6.0beta03 [December 22, 2011]
+  Start-up code size improvements, error handler flexibility. These changes
+    alter how the tricky allocation of the initial png_struct and png_info
+    structures are handled. png_info is now handled in pretty much the same
+    way as everything else, except that the allocations handle NULL return
+    silently.  png_struct is changed in a similar way on allocation and on
+    deallocation a 'safety' error handler is put in place (which should never
+    be required).  The error handler itself is changed to permit mismatches
+    in the application and libpng error buffer size; however, this means a
+    silent change to the API to return the jmp_buf if the size doesn't match
+    the size from the libpng compilation; libpng now allocates the memory and
+    this may fail.  Overall these changes result in slight code size
+    reductions; however, this is a reduction in code that is always executed
+    so is particularly valuable.  Overall on a 64-bit system the libpng DLL
+    decreases in code size by 1733 bytes.  pngerror.o increases in size by
+    about 465 bytes because of the new functionality.
+  Added png_convert_to_rfc1123_buffer() and deprecated png_convert_to_rfc1123()
+    to avoid including a spurious buffer in the png_struct.
+
+Version 1.6.0beta04 [December 30, 2011]
+  Regenerated configure scripts with automake-1.11.2
+  Eliminated png_info_destroy(). It is now used only in png.c and only calls
+    one other internal function and memset().
+  Enabled png_get_sCAL_fixed() if floating point APIs are enabled. Previously
+    it was disabled whenever internal fixed point arithmetic was selected,
+    which meant it didn't exist even on systems where FP was available but not
+    preferred.
+  Added pngvalid.c compile time checks for const APIs.
+  Implemented 'restrict' for png_info and png_struct. Because of the way
+    libpng works both png_info and png_struct are always accessed via a
+    single pointer.  This means adding C99 'restrict' to the pointer gives
+    the compiler some opportunity to optimize the code.  This change allows
+    that.
+  Moved AC_MSG_CHECKING([if libraries can be versioned]) later to the proper
+    location in configure.ac (Gilles Espinasse).
+  Changed png_memcpy to C assignment where appropriate. Changed all those
+    uses of png_memcpy that were doing a simple assignment to assignments
+    (all those cases where the thing being copied is a non-array C L-value).
+  Added some error checking to png_set_*() routines.
+  Removed the reference to the non-exported function png_memcpy() from
+    example.c.
+  Fixed the Visual C 64-bit build - it requires jmp_buf to be aligned, but
+    it had become misaligned.
+  Revised contrib/pngminus/pnm2png.c to avoid warnings when png_uint_32
+    and unsigned long are of different sizes.
+
+Version 1.6.0beta05 [January 15, 2012]
+  Updated manual with description of the simplified API (copied from png.h)
+  Fix bug in pngerror.c: some long warnings were being improperly truncated
+    (CVE-2011-3464, bug introduced in libpng-1.5.3beta05).
+
+Version 1.6.0beta06 [January 24, 2012]
+  Added palette support to the simplified APIs. This commit
+    changes some of the macro definitions in png.h, app code
+    may need corresponding changes.
+  Increased the formatted warning buffer to 192 bytes.
+  Added color-map support to simplified API. This is an initial version for
+    review; the documentation has not yet been updated.
+  Fixed Min/GW uninstall to remove libpng.dll.a
+
+Version 1.6.0beta07 [January 28, 2012]
+  Eliminated Intel icc/icl compiler warnings. The Intel (GCC derived)
+    compiler issues slightly different warnings from those issued by the
+    current versions of GCC. This eliminates those warnings by
+    adding/removing casts and small code rewrites.
+  Updated configure.ac from autoupdate: added --enable-werror option.
+    Also some layout regularization and removal of introduced tab characters
+    (replaced with 3-character indentation).  Obsolete macros identified by
+    autoupdate have been removed; the replacements are all in 2.59 so
+    the pre-req hasn't been changed.  --enable-werror checks for support
+    for -Werror (or the given argument) in the compiler.  This mimics the
+    gcc configure option by allowing -Werror to be turned on safely; without
+    the option the tests written in configure itself fail compilation because
+    they cause compiler warnings.
+  Rewrote autogen.sh to run autoreconf instead of running tools one-by-one.
+  Conditionalize the install rules for MINGW and CYGWIN in CMakeLists.txt and
+    set CMAKE_LIBRARY_OUTPUT_DIRECTORY to "lib" on all platforms (C. Yapp).
+  Freeze libtool files in the 'scripts' directory. This version of autogen.sh
+    attempts to dissuade people from running it when it is not, or should not,
+    be necessary.  In fact, autogen.sh does not work when run in a libpng
+    directory extracted from a tar distribution anymore. You must run it in
+    a GIT clone instead.
+  Added two images to contrib/pngsuite (1-bit and 2-bit transparent grayscale),
+    and renamed three whose names were inconsistent with those in
+    pngsuite/README.txt.
+
+Version 1.6.0beta08 [February 1, 2012]
+  Fixed Image::colormap misalignment in pngstest.c
+  Check libtool/libtoolize version number (2.4.2) in configure.ac
+  Divide test-pngstest.sh into separate pngstest runs for basic and
+    transparent images.
+  Moved automake options to AM_INIT_AUTOMAKE in configure.ac
+  Added color-tests, silent-rules (Not yet implemented in Makefile.am) and
+    version checking to configure.ac
+  Improved pngstest speed by not doing redundant tests and add const to
+    the background parameter of png_image_finish_read. The --background
+    option is now done automagically only when required, so that commandline
+    option no longer exists.
+  Cleaned up pngpriv.h to consistently declare all functions and data.
+    Also eliminated PNG_CONST_DATA, which is apparently not needed but we
+    can't be sure until it is gone.
+  Added symbol prefixing that allows all the libpng external symbols
+    to be prefixed (suggested by Reuben Hawkins).
+  Updated "ftbb*.png" list in the owatcom and vstudio projects.
+  Fixed 'prefix' builds on clean systems. The generation of pngprefix.h
+    should not require itself.
+  Updated INSTALL to explain that autogen.sh must be run in a GIT clone,
+    not in a libpng directory extracted from a tar distribution.
+
+Version 1.6.0beta09 [February 1, 2012]
+  Reverted the prebuilt configure files to libpng-1.6.0beta05 condition.
+
+Version 1.6.0beta10 [February 3, 2012]
+  Added Z_SOLO for zlib-1.2.6+ and correct pngstest tests
+  Updated list of test images in CMakeLists.txt
+  Updated the prebuilt configure files to current condition.
+  Revised INSTALL information about autogen.sh; it works in tar distributions.
+
+Version 1.6.0beta11 [February 16, 2012]
+  Fix character count in pngstest command in projects/owatcom/pngstest.tgt
+  Revised test-pngstest.sh to report PASS/FAIL for each image.
+  Updated documentation about the simplified API.
+  Corrected estimate of error in libpng png_set_rgb_to_gray API.  The API is
+    extremely inaccurate for sRGB conversions because it uses an 8-bit
+    intermediate linear value and it does not use the sRGB transform, so it
+    suffers from the known instability in gamma transforms for values close
+    to 0 (see Poynton).  The net result is that the calculation has a maximum
+    error of 14.99/255; 0.5/255^(1/2.2).  pngstest now uses 15 for the
+    permitted 8-bit error. This may still not be enough because of arithmetic
+    error.
+  Removed some unused arrays (with #ifdef) from png_read_push_finish_row().
+  Fixed a memory overwrite bug in simplified read of RGB PNG with
+    non-linear gamma Also bugs in the error checking in pngread.c and changed
+    quite a lot of the checks in pngstest.c to be correct; either correctly
+    written or not over-optimistic.  The pngstest changes are insufficient to
+    allow all possible RGB transforms to be passed; pngstest cmppixel needs
+    to be rewritten to make it clearer which errors it allows and then changed
+    to permit known inaccuracies.
+  Removed tests for no-longer-used *_EMPTY_PLTE_SUPPORTED from pngstruct.h
+  Fixed fixed/float API export conditionals. 1) If FIXED_POINT or
+    FLOATING_POINT options were switched off, png.h ended up with lone ';'
+    characters.  This is not valid ANSI-C outside a function.  The ';'
+    characters have been moved inside the definition of PNG_FP_EXPORT and
+    PNG_FIXED_EXPORT. 2) If either option was switched off, the declaration
+    of the corresponding functions were completely omitted, even though some
+    of them are still used internally.  The result is still valid, but
+    produces warnings from gcc with some warning options (including -Wall). The
+    fix is to cause png.h to declare the functions with PNG_INTERNAL_FUNCTION
+    when png.h is included from pngpriv.h.
+  Check for invalid palette index while reading paletted PNG.  When one is
+    found, issue a warning and increase png_ptr->num_palette accordingly.
+    Apps are responsible for checking to see if that happened.
+
+Version 1.6.0beta12 [February 18, 2012]
+  Do not increase num_palette on invalid_index.
+  Relocated check for invalid palette index to pngrtran.c, after unpacking
+    the sub-8-bit pixels.
+  Fixed CVE-2011-3026 buffer overrun bug.  This bug was introduced when
+    iCCP chunk support was added at libpng-1.0.6. Deal more correctly with the
+    test on iCCP chunk length. Also removed spurious casts that may hide
+    problems on 16-bit systems.
+
+Version 1.6.0beta13 [February 24, 2012]
+  Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from
+    pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
+    now that png_ptr->buffer is inaccessible to applications, the special
+    handling is no longer useful.
+  Added PNG_SAFE_LIMITS feature to pnglibconf.dfa, pngpriv.h, and new
+    pngusr.dfa to reset the user limits to safe ones if PNG_SAFE_LIMITS is
+    defined.  To enable, use "CPPFLAGS=-DPNG_SAFE_LIMITS_SUPPORTED=1" on the
+    configure command or put #define PNG_SAFE_LIMITS_SUPPORTED in
+    pnglibconf.h.prebuilt and pnglibconf.h.
+
+Version 1.6.0beta14 [February 27, 2012]
+  Added information about the new limits in the manual.
+  Updated Makefile.in
+
+Version 1.6.0beta15 [March 2, 2012]
+  Removed unused "current_text" members of png_struct and the png_free()
+    of png_ptr->current_text from pngread.c
+  Rewrote pngstest.c for substantial speed improvement.
+  Fixed transparent pixel and 16-bit rgb tests in pngstest and removed a
+    spurious check in pngwrite.c
+  Added PNG_IMAGE_FLAG_FAST for the benefit of applications that store
+    intermediate files, or intermediate in-memory data, while processing
+    image data with the simplified API.  The option makes the files larger
+    but faster to write and read.  pngstest now uses this by default; this
+    can be disabled with the --slow option.
+  Improved pngstest fine tuning of error numbers, new test file generator.
+    The generator generates images that test the full range of sample values,
+    allow the error numbers in pngstest to be tuned and checked.  makepng
+    also allows generation of images with extra chunks, although this is
+    still work-in-progress.
+  Added check for invalid palette index while reading.
+  Fixed some bugs in ICC profile writing. The code should now accept
+    all potentially valid ICC profiles and reject obviously invalid ones.
+    It now uses png_error() to do so rather than casually writing a PNG
+    without the necessary color data.
+  Removed whitespace from the end of lines in all source files and scripts.
+
+Version 1.6.0beta16 [March 6, 2012]
+  Relocated palette-index checking function from pngrutil.c to pngtrans.c
+  Added palette-index checking while writing.
+  Changed png_inflate() and calling routines to avoid overflow problems.
+    This is an intermediate check-in that solves the immediate problems and
+    introduces one performance improvement (avoiding a copy via png_ptr->zbuf.)
+    Further changes will be made to make ICC profile handling more secure.
+  Fixed build warnings (MSVC, GCC, GCC v3). Cygwin GCC with default options
+    declares 'index' as a global, causing a warning if it is used as a local
+    variable.  GCC 64-bit warns about assigning a (size_t) (unsigned 64-bit)
+    to an (int) (signed 32-bit).  MSVC, however, warns about using the
+    unary '-' operator on an unsigned value (even though it is well defined
+    by ANSI-C to be ~x+1).  The padding calculation was changed to use a
+    different method.  Removed the tests on png_ptr->pass.
+  Added contrib/libtests/tarith.c to test internal arithmetic functions from
+    png.c. This is a libpng maintainer program used to validate changes to the
+    internal arithmetic functions.
+  Made read 'inflate' handling like write 'deflate' handling. The read
+    code now claims and releases png_ptr->zstream, like the write code.
+    The bug whereby the progressive reader failed to release the zstream
+    is now fixed, all initialization is delayed, and the code checks for
+    changed parameters on deflate rather than always calling
+    deflatedEnd/deflateInit.
+  Validate the zTXt strings in pngvalid.
+  Added code to validate the windowBits value passed to deflateInit2().
+    If the call to deflateInit2() is wrong a png_warning will be issued
+    (in fact this is harmless, but the PNG data produced may be sub-optimal).
+
+Version 1.6.0beta17 [March 10, 2012]
+  Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition.
+  Reject all iCCP chunks after the first, even if the first one is invalid.
+  Deflate/inflate was reworked to move common zlib calls into single
+    functions [rw]util.c.  A new shared keyword check routine was also added
+    and the 'zbuf' is no longer allocated on progressive read.  It is now
+    possible to call png_inflate() incrementally.  A warning is no longer
+    issued if the language tag or translated keyword in the iTXt chunk
+    has zero length.
+  If benign errors are disabled use maximum window on ancillary inflate.
+    This works round a bug introduced in 1.5.4 where compressed ancillary
+    chunks could end up with a too-small windowBits value in the deflate
+    header.
+
+Version 1.6.0beta18 [March 16, 2012]
+  Issue a png_benign_error() instead of png_warning() about bad palette index.
+  In pngtest, treat benign errors as errors if "-strict" is present.
+  Fixed an off-by-one error in the palette index checking function.
+  Fixed a compiler warning under Cygwin (Windows-7, 32-bit system)
+  Revised example.c to put text strings in a temporary character array
+    instead of directly assigning string constants to png_textp members.
+    This avoids compiler warnings when -Wwrite-strings is enabled.
+  Added output flushing to aid debugging under Visual Studio. Unfortunately
+    this is necessary because the VS2010 output window otherwise simply loses
+    the error messages on error (they weren't flushed to the window before
+    the process exited, apparently!)
+  Added configuration support for benign errors and changed the read
+    default. Also changed some warnings in the iCCP and sRGB handling
+    from to benign errors. Configuration now makes read benign
+    errors warnings and write benign errors to errors by default (thus
+    changing the behavior on read).  The simplified API always forces
+    read benign errors to warnings (regardless of the system default, unless
+    this is disabled in which case the simplified API can't be built.)
+
+Version 1.6.0beta19 [March 18, 2012]
+  Work around for duplicate row start calls; added warning messages.
+    This turns on PNG_FLAG_DETECT_UNINITIALIZED to detect app code that
+    fails to call one of the 'start' routines (not enabled in libpng-1.5
+    because it is technically an API change, since it did normally work
+    before.)  It also makes duplicate calls to png_read_start_row (an
+    internal function called at the start of the image read) benign, as
+    they were before changes to use png_inflate_claim. Somehow webkit is
+    causing this to happen; this is probably a mis-feature in the zlib
+    changes so this commit is only a work-round.
+  Removed erroneous setting of DETECT_UNINITIALIZED and added more
+    checks. The code now does a png_error if an attempt is made to do the
+    row initialization twice; this is an application error and it has
+    serious consequences because the transform data in png_struct is
+    changed by each call.
+  Added application error reporting and added chunk names to read
+    benign errors; also added --strict to pngstest - not enabled
+    yet because a warning is produced.
+  Avoid the double gamma correction warning in the simplified API.
+    This allows the --strict option to pass in the pngstest checks
+
+Version 1.6.0beta20 [March 29, 2012]
+  Changed chunk handler warnings into benign errors, incrementally load iCCP
+  Added checksum-icc.c to contrib/tools
+  Prevent PNG_EXPAND+PNG_SHIFT doing the shift twice.
+  Recognize known sRGB ICC profiles while reading; prefer writing the
+    iCCP profile over writing the sRGB chunk, controlled by the
+    PNG_sRGB_PROFILE_CHECKS option.
+  Revised png_set_text_2() to avoid potential memory corruption (fixes
+    CVE-2011-3048, also known as CVE-2012-3425).
+
+Version 1.6.0beta21 [April 27, 2012]
+  Revised scripts/makefile.darwin: use system zlib; remove quotes around
+    architecture list; add missing ppc architecture; add architecture options
+    to shared library link; don't try to create a shared lib based on missing
+    RELEASE variable.
+  Enable png_set_check_for_invalid_index() for both read and write.
+  Removed #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED in pngpriv.h around
+    declaration of png_handle_unknown().
+  Added -lssp_nonshared in a comment in scripts/makefile.freebsd
+    and changed deprecated NOOBJ and NOPROFILE to NO_OBJ and NO_PROFILE.
+
+Version 1.6.0beta22 [May 23, 2012]
+  Removed need for -Wno-cast-align with clang.  clang correctly warns on
+    alignment increasing pointer casts when -Wcast-align is passed. This
+    fixes the cases that clang warns about either by eliminating the
+    casts from png_bytep to png_uint_16p (pngread.c), or, for pngrutil.c
+    where the cast is previously verified or pngstest.c where it is OK, by
+    introducing new png_aligncast macros to do the cast in a way that clang
+    accepts.
+
+Version 1.6.0beta23 [June 6, 2012]
+  Revised CMakeLists.txt to not attempt to make a symlink under mingw.
+  Made fixes for new optimization warnings from gcc 4.7.0. The compiler
+    performs an optimization which is safe; however it then warns about it.
+    Changing the type of 'palette_number' in pngvalid.c removes the warning.
+  Do not depend upon a GCC feature macro being available for use in generating
+    the linker mapfile symbol prefix.
+  Improved performance of new do_check_palette_indexes() function (only
+    update the value when it actually increases, move test for whether
+    the check is wanted out of the function.
+
+Version 1.6.0beta24 [June 7, 2012]
+  Don't check palette indexes if num_palette is 0 (as it can be in MNG files).
+
+Version 1.6.0beta25 [June 16, 2012]
+  Revised png_set_keep_unknown_chunks() so num_chunks < 0 means ignore all
+    unknown chunks and all known chunks except for IHDR, PLTE, tRNS, IDAT,
+    and IEND.  Previously it only meant ignore all unknown chunks, the
+    same as num_chunks == 0. Revised png_image_skip_unused_chunks() to
+    provide a list of chunks to be processed instead of a list of chunks to
+    ignore.  Revised contrib/gregbook/readpng2.c accordingly.
+
+Version 1.6.0beta26 [July 10, 2012]
+  Removed scripts/makefile.cegcc from the *.zip and *.7z distributions; it
+    depends on configure, which is not included in those archives.
+  Moved scripts/chkfmt to contrib/tools.
+  Changed "a+w" to "u+w" in Makefile.in to fix CVE-2012-3386.
+
+Version 1.6.0beta27 [August 11, 2012]
+  Do not compile PNG_DEPRECATED, PNG_ALLOC and PNG_PRIVATE when __GNUC__ < 3.
+  Do not use __restrict when GNUC is <= 3.1
+  Removed references to png_zalloc() and png_zfree() from the manual.
+  Fixed configurations where floating point is completely disabled.  Because
+    of the changes to support symbol prefixing PNG_INTERNAL_FUNCTION declares
+    floating point APIs during libpng builds even if they are completely
+    disabled. This requires the png floating point types (png_double*) to be
+    declared even though the functions are never actually defined.  This
+    change provides a dummy definition so that the declarations work, yet any
+    implementation will fail to compile because of an incomplete type.
+  Re-eliminated the use of strcpy() in pngtest.c.  An unnecessary 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 desirable 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, 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 23, 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.
+
+Version 1.6.0beta36 [January 2, 2013]
+  Discontinued distributing libpng-1.x.x.tar.bz2.
+  Discontinued distributing libpng-1.7.0-1.6.0-diff.txt and similar.
+  Rebuilt configure with autoconf-2.69 (inadvertently not done in beta33)
+  Fixed 'make distcheck' on SUN OS - libpng.so was not being removed
+
+Version 1.6.0beta37 [January 10, 2013]
+  Fixed conceivable but difficult to repro overflow. Also added two test
+    programs to generate and test a PNG which should have the problem.
+
+Version 1.6.0beta39 [January 19, 2013]
+  Again corrected attempt at overflow detection in png_set_unknown_chunks()
+  (CVE-2013-7353).  Added overflow detection in png_set_sPLT() and
+  png_set_text_2() (CVE-2013-7354).
+
+Version 1.6.0beta40 [January 20, 2013]
+  Use consistent handling of overflows in text, sPLT and unknown png_set_* APIs
+
+Version 1.6.0rc01 [January 26, 2013]
+  No changes.
+
+Version 1.6.0rc02 [February 4, 2013]
+  Added png_get_palette_max() function.
+
+Version 1.6.0rc03 [February 5, 2013]
+  Fixed the png_get_palette_max API.
+
+Version 1.6.0rc04 [February 7, 2013]
+  Turn serial tests back on (recently turned off by autotools upgrade).
+
+Version 1.6.0rc05 [February 8, 2013]
+  Update manual about png_get_palette_max().
+
+Version 1.6.0rc06 [February 9, 2013]
+  Fixed missing dependency in --prefix builds The intermediate
+    internal 'prefix.h' file can only be generated correctly after
+    pnglibconf.h, however the dependency was not in Makefile.am.  The
+    symptoms are unpredictable depending on the order make chooses to
+    build pngprefix.h and pnglibconf.h, often the error goes unnoticed
+    because there is a system pnglibconf.h to use instead.
+
+Version 1.6.0rc07 [February 10, 2013]
+  Enclosed the new png_get_palette_max in #ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+    block, and revised pnglibconf.h and pnglibconf.h.prebuilt accordingly.
+
+Version 1.6.0rc08 [February 10, 2013]
+  Fix typo in png.h #ifdef
+
+Version 1.6.0 [February 14, 2013]
+  No changes.
+
+Version 1.6.1beta01 [February 16, 2013]
+  Made symbol prefixing work with the ARM neon optimizations. Also allow
+    pngpriv.h to be included for preprocessor definitions only, so it can
+    be used in non-C/C++ files. Back ported from libpng 1.7.
+  Made sRGB check numbers consistent.
+  Ported libpng 1.5 options.awk/dfn file handling to 1.6, fixed one bug.
+  Removed cc -E workround, corrected png_get_palette_max API Tested on
+    SUN OS cc 5.9, which demonstrates the tokenization problem previously
+    avoided by using /lib/cpp.  Since all .dfn output is now protected in
+    double quotes unless it is to be macro substituted the fix should
+    work everywhere.
+  Enabled parallel tests - back ported from libpng-1.7.
+  scripts/pnglibconf.dfa formatting improvements back ported from libpng17.
+  Fixed a race condition in the creation of the build 'scripts' directory
+    while building with a parallel make.
+  Use approved/supported Android method to check for NEON, use Linux/POSIX
+    1003.1 API to check /proc/self/auxv avoiding buffer allocation and other
+    library calls (ported from libpng15).
+
+Version 1.6.1beta02 [February 19, 2013]
+  Use parentheses more consistently in "#if defined(MACRO)" tests.
+  Folded long lines.
+  Reenabled code to allow zero length PLTE chunks for MNG.
+
+Version 1.6.1beta03 [February 22, 2013]
+  Fixed ALIGNED_MEMORY support.
+  Added a new configure option:
+    --enable-arm-neon=always will stop the run-time checks. New checks
+    within arm/arm_init.c will cause the code not to be compiled unless
+    __ARM_NEON__ is set. This should make it fail safe (if someone asks
+    for it on then the build will fail if it can't be done.)
+  Updated the INSTALL document.
+
+Version 1.6.1beta04 [February 27, 2013]
+  Revised INSTALL to recommend using CPPFLAGS instead of INCLUDES.
+  Revised scripts/makefile.freebsd to respect ZLIBLIB and ZLIBINC.
+  Revised scripts/dfn.awk to work with the buggy MSYS awk that has trouble
+    with CRLF line endings.
+
+Version 1.6.1beta05 [March 1, 2013]
+  Avoid a possible memory leak in contrib/gregbook/readpng.c
+
+Version 1.6.1beta06 [March 4, 2013]
+  Better documentation of unknown handling API interactions.
+  Corrected Android builds and corrected libpng.vers with symbol
+    prefixing.  It also makes those tests compile and link on Android.
+  Added an API png_set_option() to set optimization options externally,
+    providing an alternative and general solution for the non-portable
+    run-time tests used by the ARM Neon code, using the PNG_ARM_NEON option.
+  The order of settings vs options in pnglibconf.h is reversed to allow
+    settings to depend on options and options can now set (or override) the
+    defaults for settings.
+
+Version 1.6.1beta07 [March 7, 2013]
+  Corrected simplified API default gamma for color-mapped output, added
+    a flag to change default. In 1.6.0 when the simplified API was used
+    to produce color-mapped output from an input image with no gamma
+    information the gamma assumed for the input could be different from
+    that assumed for non-color-mapped output.  In particular 16-bit depth
+    input files were assumed to be sRGB encoded, whereas in the 'direct'
+    case they were assumed to have linear data.  This was an error.  The
+    fix makes the simplified API treat all input files the same way and
+    adds a new flag to the png_image::flags member to allow the
+    application/user to specify that 16-bit files contain sRGB data
+    rather than the default linear.
+  Fixed bugs in the pngpixel and makepng test programs.
+
+Version 1.6.1beta08 [March 7, 2013]
+  Fixed CMakelists.txt to allow building a single variant of the library
+    (Claudio Bley):
+  Introduced a PNG_LIB_TARGETS variable that lists all activated library
+    targets.  It is an error if this variable ends up empty, ie. you have
+    to build at least one library variant.
+  Made the *_COPY targets only depend on library targets actually being build.
+  Use PNG_LIB_TARGETS to unify a code path.
+  Changed the CREATE_SYMLINK macro to expect the full path to a file as the
+    first argument. When symlinking the filename component of that path is
+    determined and used as the link target.
+  Use copy_if_different in the CREATE_SYMLINK macro.
+
+Version 1.6.1beta09 [March 13, 2013]
+  Eliminated two warnings from the Intel C compiler. The warnings are
+    technically valid, although a reasonable treatment of division would
+    show it to be incorrect.
+
+Version 1.6.1rc01 [March 21, 2013]
+  No changes.
+
+Version 1.6.1 [March 28, 2013]
+  No changes.
+
+Version 1.6.2beta01 [April 14, 2013]
+  Updated documentation of 1.5.x to 1.6.x changes in iCCP chunk handling.
+  Fixed incorrect warning of excess deflate data. End condition - the
+    warning would be produced if the end of the deflate stream wasn't read
+    in the last row.  The warning is harmless.
+  Corrected the test on user transform changes on read. It was in the
+    png_set of the transform function, but that doesn't matter unless the
+    transform function changes the rowbuf size, and that is only valid if
+    transform_info is called.
+  Corrected a misplaced closing bracket in contrib/libtests/pngvalid.c
+    (Flavio Medeiros).
+  Corrected length written to uncompressed iTXt chunks (Samuli Suominen).
+    Bug was introduced in libpng-1.6.0.
+
+Version 1.6.2rc01 [April 18, 2013]
+  Added contrib/tools/fixitxt.c, to repair the erroneous iTXt chunk length
+    written by libpng-1.6.0 and 1.6.1.
+  Disallow storing sRGB information when the sRGB is not supported.
+
+Version 1.6.2rc02 [April 18, 2013]
+  Merge pngtest.c with libpng-1.7.0
+
+Version 1.6.2rc03 [April 22, 2013]
+  Trivial spelling cleanup.
+
+Version 1.6.2rc04 and 1.6.2rc05 [omitted]
+
+Version 1.6.2rc06 [April 24, 2013]
+  Reverted to version 1.6.2rc03.  Recent changes to arm/neon support
+    have been ported to libpng-1.7.0beta09 and will reappear in version
+    1.6.3beta01.
+
+Version 1.6.2 [April 25, 2013]
+  No changes.
+
+Version 1.6.3beta01 [April 25, 2013]
+  Revised stack marking in arm/filter_neon.S and configure.ac.
+  Ensure that NEON filter stuff is completely disabled when switched 'off'.
+    Previously the ARM NEON specific files were still built if the option
+    was switched 'off' as opposed to being explicitly disabled.
+
+Version 1.6.3beta02 [April 26, 2013]
+  Test for 'arm*' not just 'arm' in the host_cpu configure variable.
+  Rebuilt the configure scripts.
+
+Version 1.6.3beta03 [April 30, 2013]
+  Expanded manual paragraph about writing private chunks, particularly
+    the need to call png_set_keep_unknown_chunks() when writing them.
+  Avoid dereferencing NULL pointer possibly returned from
+    png_create_write_struct() (Andrew Church).
+
+Version 1.6.3beta05 [May 9, 2013]
+  Calculate our own zlib windowBits when decoding rather than trusting the
+    CMF bytes in the PNG datastream.
+  Added an option to force maximum window size for inflating, which was
+    the behavior of libpng15 and earlier, via a new PNG_MAXIMUM_INFLATE_WINDOW
+    option for png_set_options().
+  Added png-fix-itxt and png-fix-too-far-back to the built programs and
+    removed warnings from the source code and timepng that are revealed as
+    a result.
+  Detect wrong libpng versions linked to png-fix-too-far-back, which currently
+    only works with libpng versions that can be made to reliably fail when
+    the deflate data contains an out-of-window reference.  This means only
+    1.6 and later.
+  Fixed gnu issues: g++ needs a static_cast, gcc 4.4.7 has a broken warning
+    message which it is easier to work round than ignore.
+  Updated contrib/pngminus/pnm2png.c (Paul Stewart):
+    Check for EOF
+    Ignore "#" delimited comments in input file to pnm2png.c.
+    Fixed whitespace handling
+    Added a call to png_set_packing()
+    Initialize dimension values so if sscanf fails at least we have known
+      invalid values.
+  Attempt to detect configuration issues with png-fix-too-far-back, which
+    requires both the correct libpng and the correct zlib to function
+    correctly.
+  Check ZLIB_VERNUM for mismatches, enclose #error in quotes
+  Added information in the documentation about problems with and fixes for
+    the bad CRC and bad iTXt chunk situations.
+
+Version 1.6.3beta06 [May 12, 2013]
+  Allow contrib/pngminus/pnm2png.c to compile without WRITE_INVERT and
+    WRITE_PACK supported (writes error message that it can't read P1 or
+    P4 PBM files).
+  Improved png-fix-too-far-back usage message, added --suffix option.
+  Revised contrib/pngminim/*/makefile to generate pnglibconf.h with the
+    right zlib header files.
+  Separated CPPFLAGS and CFLAGS in contrib/pngminim/*/makefile
+
+Version 1.6.3beta07 [June 8, 2013]
+  Removed a redundant test in png_set_IHDR().
+  Added set(CMAKE_CONFIGURATION_TYPES ...) to CMakeLists.txt (Andrew Hundt)
+  Deleted set(CMAKE_BUILD_TYPE) block from CMakeLists.txt
+  Enclose the prototypes for the simplified write API in
+    #ifdef PNG_STDIO_SUPPORTED/#endif
+  Make ARM NEON support work at compile time (not just configure time).
+    This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when
+    using a compiler that compiles for multiple architectures at one time.
+  Removed PNG_FILTER_OPTIMIZATIONS and PNG_ARM_NEON_SUPPORTED from
+    pnglibconf.h, allowing more of the decisions to be made internally
+    (pngpriv.h) during the compile.  Without this, symbol prefixing is broken
+    under certain circumstances on ARM platforms.  Now only the API parts of
+    the optimizations ('check' vs 'api') are exposed in the public header files
+    except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
+    decision about whether or not to use the optimizations.
+  Protect symbol prefixing against CC/CPPFLAGS/CFLAGS usage.
+    Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
+    on __ARM_NEON__ from configure time to compile time.  This breaks symbol
+    prefixing because the definition of the special png_init_filter_functions
+    call was hidden at configure time if the relevant compiler arguments are
+    passed in CFLAGS as opposed to CC.  This change attempts to avoid all
+    the confusion that would result by declaring the init function even when
+    it is not used, so that it will always get prefixed.
+
+Version 1.6.3beta08 [June 18, 2013]
+  Revised libpng.3 so that "doclifter" can process it.
+
+Version 1.6.3beta09 [June 27, 2013]
+  Revised example.c to illustrate use of PNG_DEFAULT_sRGB and PNG_GAMMA_MAC_18
+    as parameters for png_set_gamma().  These have been available since
+    libpng-1.5.4.
+  Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c and revised it
+    to check all compressed chunks known to libpng.
+
+Version 1.6.3beta10 [July 5, 2013]
+  Updated documentation to show default behavior of benign errors correctly.
+  Only compile ARM code when PNG_READ_SUPPORTED is defined.
+  Fixed undefined behavior in contrib/tools/pngfix.c and added new strip
+    option. pngfix relied on undefined behavior and even a simple change from
+    gcc to g++ caused it to fail.  The new strip option 'unsafe' has been
+    implemented and is the default if --max is given.  Option names have
+    been clarified, with --strip=transform now stripping the bKGD chunk,
+    which was stripped previously with --strip=unused.
+  Added all documented chunk types to pngpriv.h
+  Unified pngfix.c source with libpng17.
+
+Version 1.6.3rc01 [July 11, 2013]
+  No changes.
+
+Version 1.6.3 [July 18, 2013]
+  Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
+  Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
+    may be erroneously issued by code-checking applications.
+
+Version 1.6.4beta01 [August 21, 2013]
+  Added information about png_set_options() to the manual.
+  Delay calling png_init_filter_functions() until a row with nonzero filter
+    is found.
+
+Version 1.6.4beta02 [August 30, 2013]
+  Fixed inconsistent conditional compilation of png_chunk_unknown_handling()
+    prototype, definition, and usage.  Made it depend on
+    PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere.
+
+Version 1.6.4rc01 [September 5, 2013]
+  No changes.
+
+Version 1.6.4 [September 12, 2013]
+  No changes.
+
+Version 1.6.5 [September 14, 2013]
+  Removed two stray lines of code from arm/arm_init.c.
+
+Version 1.6.6 [September 16, 2013]
+  Removed two stray lines of code from arm/arm_init.c, again.
+
+Version 1.6.7beta01 [September 30, 2013]
+  Revised unknown chunk code to correct several bugs in the NO_SAVE_/NO_WRITE
+    combination
+  Allow HANDLE_AS_UNKNOWN to work when other options are configured off. Also
+    fixed the pngminim makefiles to work when $(MAKEFLAGS) contains stuff
+    which terminates the make options (as by default in recent versions of
+    Gentoo).
+  Avoid up-cast warnings in pngvalid.c. On ARM the alignment requirements of
+    png_modifier are greater than that of png_store and as a consequence
+    compilation of pngvalid.c results in a warning about increased alignment
+    requirements because of the bare cast to (png_modifier*). The code is safe,
+    because the pointer is known to point to a stack allocated png_modifier,
+    but this change avoids the warning.
+  Fixed default behavior of ARM_NEON_API. If the ARM NEON API option was
+    compiled without the CHECK option it defaulted to on, not off.
+  Check user callback behavior in pngunknown.c. Previous versions compiled
+    if SAVE_UNKNOWN was not available but did nothing since the callback
+    was never implemented.
+  Merged pngunknown.c with 1.7 version and back ported 1.7 improvements/fixes
+
+Version 1.6.7beta02 [October 12, 2013]
+  Made changes for compatibility with automake 1.14:
+    1) Added the 'compile' program to the list of programs that must be cleaned
+       in autogen.sh
+    2) Added 'subdir-objects' which causes .c files in sub-directories to be
+       compiled such that the corresponding .o files are also in the
+       sub-directory.  This is because automake 1.14 warns that the
+       current behavior of compiling to the top level directory may be removed
+       in the future.
+    3) Updated dependencies on pnglibconf.h to match the new .o locations and
+       added all the files in contrib/libtests and contrib/tools that depend
+       on pnglibconf.h
+    4) Added 'BUILD_SOURCES = pnglibconf.h'; this is the automake recommended
+       way of handling the dependencies of sources that are machine generated;
+       unfortunately it only works if the user does 'make all' or 'make check',
+       so the dependencies (3) are still required.
+  Cleaned up (char*) casts of zlib messages. The latest version of the Intel C
+    compiler complains about casting a string literal as (char*), so copied the
+    treatment of z_const from the library code into pngfix.c
+  Simplified error message code in pngunknown. The simplification has the
+    useful side effect of avoiding a bogus warning generated by the latest
+    version of the Intel C compiler (it objects to
+    condition ? string-literal : string-literal).
+  Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
+    removing the 1.14 'compile' script but never checking for it.
+
+Version 1.6.7beta03 [October 19, 2013]
+  Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
+    arm/filter_neon_intrinsics.c; enable with -mfpu=neon.
+  Revised pngvalid to generate size images with as many filters as it can
+    manage, limited by the number of rows.
+  Cleaned up ARM NEON compilation handling. The tests are now in pngpriv.h
+    and detect the broken GCC compilers.
+
+Version 1.6.7beta04 [October 26, 2013]
+  Allow clang derived from older GCC versions to use ARM intrinsics. This
+    causes all clang builds that use -mfpu=neon to use the intrinsics code,
+    not the assembler code.  This has only been tested on iOS 7. It may be
+    necessary to exclude some earlier clang versions but this seems unlikely.
+  Changed NEON implementation selection mechanism. This allows assembler
+    or intrinsics to be turned on at compile time during the build by defining
+    PNG_ARM_NEON_IMPLEMENTATION to the correct value (2 or 1).  This macro
+    is undefined by default and the build type is selected in pngpriv.h.
+
+Version 1.6.7rc01 [November 2, 2013]
+  No changes.
+
+Version 1.6.7rc02 [November 7, 2013]
+  Fixed #include in filter_neon_intrinsics.c and ctype macros. The ctype char
+    checking macros take an unsigned char argument, not a signed char.
+
+Version 1.6.7 [November 14, 2013]
+  No changes.
+
+Version 1.6.8beta01 [November 24, 2013]
+  Moved prototype for png_handle_unknown() in pngpriv.h outside of
+    the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
+  Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
+  Conditionally compile some unused functions reported by -Wall in
+    pngminim.
+  Fixed 'minimal' builds. Various obviously useful minimal configurations
+    don't build because of missing contrib/libtests test programs and
+    overly complex dependencies in scripts/pnglibconf.dfa. This change
+    adds contrib/conftest/*.dfa files that can be used in automatic build
+    scripts to ensure that these configurations continue to build.
+  Enabled WRITE_INVERT and WRITE_PACK in contrib/pngminim/encoder.
+  Fixed pngvalid 'fail' function declaration on the Intel C Compiler.
+    This reverts to the previous 'static' implementation and works round
+    the 'unused static function' warning by using PNG_UNUSED().
+
+Version 1.6.8beta02 [November 30, 2013]
+  Removed or marked PNG_UNUSED some harmless "dead assignments" reported
+    by clang scan-build.
+  Changed tabs to 3 spaces in png_debug macros and changed '"%s"m'
+    to '"%s" m' to improve portability among compilers.
+  Changed png_free_default() to free() in pngtest.c
+
+Version 1.6.8rc01 [December 12, 2013]
+  Tidied up pngfix inits and fixed pngtest no-write builds.
+
+Version 1.6.8rc02 [December 14, 2013]
+  Handle zero-length PLTE chunk or NULL palette with png_error()
+    instead of png_chunk_report(), which by default issues a warning
+    rather than an error, leading to later reading from a NULL pointer
+    (png_ptr->palette) in png_do_expand_palette(). This is CVE-2013-6954
+    and VU#650142.  Libpng-1.6.1 through 1.6.7 are vulnerable.
+    Libpng-1.6.0 and earlier do not have this bug.
+
+Version 1.6.8 [December 19, 2013]
+  No changes.
+
+Version 1.6.9beta01 [December 26, 2013]
+  Bookkeeping: Moved functions around (no changes). Moved transform
+    function definitions before the place where they are called so that
+    they can be made static. Move the intrapixel functions and the
+    grayscale palette builder out of the png?tran.c files. The latter
+    isn't a transform function and is no longer used internally, and the
+    former MNG specific functions are better placed in pngread/pngwrite.c
+  Made transform implementation functions static. This makes the internal
+    functions called by png_do_{read|write}_transformations static. On an
+    x86-64 DLL build (Gentoo Linux) this reduces the size of the text
+    segment of the DLL by 1208 bytes, about 0.6%. It also simplifies
+    maintenance by removing the declarations from pngpriv.h and allowing
+    easier changes to the internal interfaces.
+  Rebuilt configure scripts with automake-1.14.1 and autoconf-2.69
+    in the tar distributions.
+
+Version 1.6.9beta02 [January 1, 2014]
+  Added checks for libpng 1.5 to pngvalid.c.  This supports the use of
+    this version of pngvalid in libpng 1.5
+  Merged with pngvalid.c from libpng-1.7 changes to create a single
+    pngvalid.c
+  Removed #error macro from contrib/tools/pngfix.c (Thomas Klausner).
+  Merged pngrio.c, pngtrans.c, pngwio.c, and pngerror.c with libpng-1.7.0
+  Merged libpng-1.7.0 changes to make no-interlace configurations work
+    with test programs.
+  Revised pngvalid.c to support libpng 1.5, which does not support the
+    PNG_MAXIMUM_INFLATE_WINDOW option, so #define it out when appropriate in
+    pngvalid.c
+  Allow unversioned links created on install to be disabled in configure.
+    In configure builds 'make install' changes/adds links like png.h
+    and libpng.a to point to the newly installed, versioned, files (e.g.
+    libpng17/png.h and libpng17.a). Three new configure options and some
+    rearrangement of Makefile.am allow creation of these links to be disabled.
+
+Version 1.6.9beta03 [January 10, 2014]
+  Removed potentially misleading warning from png_check_IHDR().
+
+Version 1.6.9beta04 [January 20, 2014]
+  Updated scripts/makefile.* to use CPPFLAGS (Cosmin).
+  Added clang attribute support (Cosmin).
+
+Version 1.6.9rc01 [January 28, 2014]
+  No changes.
+
+Version 1.6.9rc02 [January 30, 2014]
+  Quiet an uninitialized memory warning from VC2013 in png_get_png().
+
+Version 1.6.9 [February 6, 2014]
+
+Version 1.6.10beta01 [February 9, 2014]
+  Backported changes from libpng-1.7.0beta30 and beta31:
+  Fixed a large number of instances where PNGCBAPI was omitted from
+    function definitions.
+  Added pngimage test program for png_read_png() and png_write_png()
+    with two new test scripts.
+  Removed dependence on !PNG_READ_EXPAND_SUPPORTED for calling
+    png_set_packing() in png_read_png().
+  Fixed combination of ~alpha with shift. On read invert alpha, processing
+    occurred after shift processing, which causes the final values to be
+    outside the range that should be produced by the shift. Reversing the
+    order on read makes the two transforms work together correctly and mirrors
+    the order used on write.
+  Do not read invalid sBIT chunks. Previously libpng only checked sBIT
+    values on write, so a malicious PNG writer could therefore cause
+    the read code to return an invalid sBIT chunk, which might lead to
+    application errors or crashes.  Such chunks are now skipped (with
+    chunk_benign_error).
+  Make png_read_png() and png_write_png() prototypes in png.h depend
+    upon PNG_READ_SUPPORTED and PNG_WRITE_SUPPORTED.
+  Support builds with unsupported PNG_TRANSFORM_* values.  All of the
+    PNG_TRANSFORM_* values are always defined in png.h and, because they
+    are used for both read and write in some cases, it is not reliable
+    to #if out ones that are totally unsupported. This change adds error
+    detection in png_read_image() and png_write_image() to do a
+    png_app_error() if the app requests something that cannot be done
+    and it adds corresponding code to pngimage.c to handle such options
+    by not attempting to test them.
+
+Version 1.6.10beta02 [February 23, 2014]
+  Moved redefines of png_error(), png_warning(), png_chunk_error(),
+    and png_chunk_warning() from pngpriv.h to png.h to make them visible
+    to libpng-calling applications.
+  Moved OS dependent code from arm/arm_init.c, to allow the included
+    implementation of the ARM NEON discovery function to be set at
+    build-time and provide sample implementations from the current code in the
+    contrib/arm-neon subdirectory. The __linux__ code has also been changed to
+    compile and link on Android by using /proc/cpuinfo, and the old linux code
+    is in contrib/arm-neon/linux-auxv.c.  The new code avoids POSIX and Linux
+    dependencies apart from opening /proc/cpuinfo and is C90 compliant.
+  Check for info_ptr == NULL early in png_read_end() so we don't need to
+    run all the png_handle_*() and depend on them to return if info_ptr == NULL.
+    This improves the performance of png_read_end(png_ptr, NULL) and makes
+    it more robust against future programming errors.
+  Check for __has_extension before using it in pngconf.h, to
+    support older Clang versions (Jeremy Sequoia).
+  Treat CRC error handling with png_set_crc_action(), instead of with
+    png_set_benign_errors(), which has been the case since libpng-1.6.0beta18.
+  Use a user warning handler in contrib/gregbook/readpng2.c instead of default,
+    so warnings will be put on stderr even if libpng has CONSOLE_IO disabled.
+  Added png_ptr->process_mode = PNG_READ_IDAT_MODE in png_push_read_chunk
+    after recognizing the IDAT chunk, which avoids an infinite loop while
+    reading a datastream whose first IDAT chunk is of zero-length.
+    This fixes CERT VU#684412 and CVE-2014-0333.
+  Don't recognize known sRGB profiles as sRGB if they have been hacked,
+    but don't reject them and don't issue a copyright violation warning.
+
+Version 1.6.10beta03 [February 25, 2014]
+  Moved some documentation from png.h to libpng.3 and libpng-manual.txt
+  Minor editing of contrib/arm-neon/README and contrib/examples/*.c
+
+Version 1.6.10rc01 [February 27, 2014]
+  Fixed typos in the manual and in scripts/pnglibconf.dfa (CFLAGS -> CPPFLAGS
+    and PNG_USR_CONFIG -> PNG_USER_CONFIG).
+
+Version 1.6.10rc02 [February 28, 2014]
+  Removed unreachable return statement after png_chunk_error()
+    in pngrutil.c
+
+Version 1.6.10rc03 [March 4, 2014]
+  Un-deprecated png_data_freer().
+
+Version 1.6.10 [March 6, 2014]
+  No changes.
+
+Version 1.6.11beta01 [March 17, 2014]
+  Use "if (value != 0)" instead of "if (value)" consistently.
+  Changed ZlibSrcDir from 1.2.5 to 1.2.8 in projects/vstudio.
+  Moved configuration information from the manual to the INSTALL file.
+
+Version 1.6.11beta02 [April 6, 2014]
+  Removed #if/#else/#endif from inside two pow() calls in pngvalid.c because
+    they were handled improperly by Portland Group's PGI-14.1 - PGI-14.3
+    when using its "__builtin_pow()" function.
+  Silence 'unused parameter' build warnings (Cosmin Truta).
+  $(CP) is now used alongside $(RM_F).  Also, use 'copy' instead of 'cp'
+    where applicable, and applied other minor makefile changes (Cosmin).
+  Don't warn about invalid dimensions exceeding user limits (Cosmin).
+  Allow an easy replacement of the default pre-built configuration
+    header with a custom header, via the make PNGLIBCONF_H_PREBUILT
+    macro (Cosmin).
+
+Version 1.6.11beta03 [April 6, 2014]
+  Fixed a typo in pngrutil.c, introduced in libpng-1.5.6, that interferes
+    with "blocky" expansion of sub-8-bit interlaced PNG files (Eric Huss).
+  Optionally use  __builtin_bswap16() in png_do_swap().
+
+Version 1.6.11beta04 [April 19, 2014]
+  Made progressive reading of interlaced images consistent with the
+    behavior of the sequential reader and consistent with the manual, by
+    moving some code out of the PNG_READ_INTERLACING_SUPPORTED blocks. The
+    row_callback now receives the proper pass number and unexpanded rows, when
+    png_combine_row() isn't built or used, and png_set_interlace_handling()
+    is not called.
+  Allow PNG_sRGB_PROFILE_CHECKING = (-1) to mean no sRGB profile checking.
+
+Version 1.6.11beta05 [April 26, 2014]
+  Do not reject ICC V2 profiles that lack padding (Kai-Uwe Behrmann).
+  Relocated closing bracket of the sRGB profile test loop to avoid getting
+    "Not recognizing known sRGB profile that has been edited" warning for
+    ICC V2 profiles that lack the MD5 signature in the profile header.
+
+Version 1.6.11beta06 [May 19, 2014]
+  Added PNG_SKIP_sRGB_CHECK_PROFILE choice for png_set_option().
+
+Version 1.6.11rc01 [May 27, 2014]
+  No changes.
+
+Version 1.6.11rc02 [June 3, 2014]
+  Test ZLIB_VERNUM instead of PNG_ZLIB_VERNUM in contrib/tools/pngfix.c
+
+Version 1.6.11 [June 5, 2014]
+  No changes.
+
+Version 1.6.12rc01 [June 6, 2014]
+  Relocated new code from 1.6.11beta06 in png.c to a point after the
+    declarations (Max Stepin).
+
+Version 1.6.12rc02 [June 7, 2014]
+  Changed file permissions of contrib/tools/intgamma.sh,
+    test-driver, and compile from 0644 to 0755 (Cosmin).
+
+Version 1.6.12rc03 [June 8, 2014]
+  Ensure "__has_attribute()" macro exists before trying to use it with
+    old clang compilers (MacPorts Ticket #43939).
+
+Version 1.6.12 [June 12, 2014]
+  No changes.
+
+Version 1.6.13beta01 [July 4, 2014]
+  Quieted -Wsign-compare and -Wclobber compiler warnings in
+    contrib/pngminus/*.c
+  Added "(void) png_ptr;" where needed in contrib/gregbook to quiet
+    compiler complaints about unused pointers.
+  Split a long output string in contrib/gregbook/rpng2-x.c.
+  Added "PNG_SET_OPTION" requirement for sRGB chunk support to pnglibconf.dfa,
+    Needed for write-only support (John Bowler).
+  Changed "if defined(__ARM_NEON__)" to
+    "if (defined(__ARM_NEON__) || defined(__ARM_NEON))" (James Wu).
+  Fixed clang no-warning builds: png_digit was defined but never used.
+
+Version 1.6.13beta02 [July 21, 2014]
+  Fixed an incorrect separator ("/" should be "\") in scripts/makefile.vcwin32
+    (bug report from Wolfgang S. Kechel).  Bug was introduced in libpng-1.6.11.
+    Also fixed makefile.bc32, makefile.bor, makefile.msc, makefile.intel, and
+    makefile.tc3 similarly.
+
+Version 1.6.13beta03 [August 3, 2014]
+  Removed scripts/makefile.elf. It has not worked since libpng-1.5.0beta14
+    due to elimination of the PNG_FUNCTION_EXPORT and PNG_DATA_EXPORT
+    definitions from pngconf.h.
+  Ensure that CMakeLists.txt makes the target "lib" directory before making
+    symbolic link into it (SourceForge bug report #226 by Rolf Timmermans).
+
+Version 1.6.13beta04 [August 8, 2014]
+  Added opinion that the ECCN (Export Control Classification Number) for
+    libpng is EAR99 to the README file.
+  Eliminated use of "$<" in makefile explicit rules, when copying
+    $PNGLIBCONF_H_PREBUILT.  This does not work on some versions of make;
+    bug introduced in libpng version 1.6.11.
+
+Version 1.6.13rc01 [August 14, 2014]
+  Made "ccopts" agree with "CFLAGS" in scripts/makefile.hp* and makefile.*sunu
+
+Version 1.6.13 [August 21, 2014]
+  No changes.
+
+Version 1.6.14beta01 [September 14, 2014]
+  Guard usage of png_ptr->options with #ifdef PNG_SET_OPTION_SUPPORTED.
+  Do not build contrib/tools/pngfix.c when PNG_SETJMP_NOT_SUPPORTED,
+    to allow "make" to complete without setjmp support (bug report by
+    Claudio Fontana)
+  Add "#include <setjmp.h>" to contrib/tools/pngfix.c (John Bowler)
+
+Version 1.6.14beta02 [September 18, 2014]
+  Use nanosleep() instead of usleep() in contrib/gregbook/rpng2-x.c
+    because usleep() is deprecated.
+  Define usleep() in contrib/gregbook/rpng2-x.c if not already defined
+    in unistd.h and nanosleep() is not available; fixes error introduced
+    in libpng-1.6.13.
+  Disable floating point exception handling in pngvalid.c when
+    PNG_FLOATING_ARITHMETIC is not supported (bug report by "zootus
+    at users.sourceforge.net").
+
+Version 1.6.14beta03 [September 19, 2014]
+  Define FE_DIVBYZERO, FE_INVALID, and FE_OVERFLOW in pngvalid.c if not
+    already defined.  Revert floating point exception handling in pngvalid.c
+    to version 1.6.14beta01 behavior.
+
+Version 1.6.14beta04 [September 27, 2014]
+  Fixed incorrect handling of the iTXt compression flag in pngrutil.c
+    (bug report by Shunsaku Hirata).  Bug was introduced in libpng-1.6.0.
+
+Version 1.6.14beta05 [October 1, 2014]
+  Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa
+
+Version 1.6.14beta06 [October 5, 2014]
+  Removed unused "text_len" parameter from private function png_write_zTXt().
+  Conditionally compile some code in png_deflate_claim(), when
+    PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled.
+  Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL.
+  Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT"
+    to pnglibconf.dfa.
+  Removed "option READ_COMPRESSED_TEXT enables READ_TEXT" from pnglibconf.dfa,
+    to make it possible to configure a libpng that supports iCCP but not TEXT.
+
+Version 1.6.14beta07 [October 7, 2014]
+  Removed "option WRITE_COMPRESSED_TEXT enables WRITE_TEXT" from pnglibconf.dfa
+  Only mark text chunks as written after successfully writing them.
+
+Version 1.6.14rc01 [October 15, 2014]
+  Fixed some typos in comments.
+
+Version 1.6.14rc02 [October 17, 2014]
+  Changed png_convert_to_rfc_1123() to png_convert_to_rfc_1123_buffer()
+    in the manual, to reflect the change made in libpng-1.6.0.
+  Updated README file to explain that direct access to the png_struct
+    and info_struct members has not been permitted since libpng-1.5.0.
+
+Version 1.6.14 [October 23, 2014]
+  No changes.
+
+Version 1.6.15beta01 [October 29, 2014]
+  Changed "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
+  Simplified png_free_data().
+  Added missing "ptr = NULL" after some instances of png_free().
+
+Version 1.6.15beta02 [November 1, 2014]
+  Changed remaining "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
+
+Version 1.6.15beta03 [November 3, 2014]
+  Added PNG_USE_ARM_NEON configuration flag (Marcin Juszkiewicz).
+
+Version 1.6.15beta04 [November 4, 2014]
+  Removed new PNG_USE_ARM_NEON configuration flag and made a one-line
+    revision to configure.ac to support ARM on aarch64 instead (John Bowler).
+
+Version 1.6.15beta05 [November 5, 2014]
+  Use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING in
+    example.c, pngtest.c, and applications in the contrib directory.
+  Fixed an out-of-range read in png_user_version_check() (Bug report from
+    Qixue Xiao, CVE-2015-8540).
+  Simplified and future-proofed png_user_version_check().
+  Fixed GCC unsigned int->float warnings. Various versions of GCC
+    seem to generate warnings when an unsigned value is implicitly
+    converted to double. This is probably a GCC bug but this change
+    avoids the issue by explicitly converting to (int) where safe.
+  Free all allocated memory in pngimage. The file buffer cache was left
+    allocated at the end of the program, harmless but it causes memory
+    leak reports from clang.
+  Fixed array size calculations to avoid warnings. At various points
+    in the code the number of elements in an array is calculated using
+    sizeof.  This generates a compile time constant of type (size_t) which
+    is then typically assigned to an (unsigned int) or (int). Some versions
+    of GCC on 64-bit systems warn about the apparent narrowing, even though
+    the same compiler does apparently generate the correct, in-range,
+    numeric constant.  This adds appropriate, safe, casts to make the
+    warnings go away.
+
+Version 1.6.15beta06 [November 6, 2014]
+  Reverted use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING
+    in the manual, example.c, pngtest.c, and applications in the contrib
+    directory.  It was incorrect advice.
+
+Version 1.6.15beta07 [November 7, 2014]
+  Removed #ifdef PNG_16BIT_SUPPORTED/#endif around png_product2(); it is
+    needed by png_reciprocal2().
+  Added #ifdef PNG_16BIT_SUPPORTED/#endif around png_log16bit() and
+    png_do_swap().
+  Changed all "#endif /* PNG_FEATURE_SUPPORTED */" to "#endif /* FEATURE */"
+
+Version 1.6.15beta08 [November 8, 2014]
+  More housecleaning in *.h
+
+Version 1.6.15rc01 [November 13, 2014]
+
+Version 1.6.15rc02 [November 14, 2014]
+  The macros passed in the command line to Borland make were ignored if
+    similarly-named macros were already defined in makefiles. This behavior
+    is different from POSIX make and other make programs.  Surround the
+    macro definitions with ifndef guards (Cosmin).
+
+Version 1.6.15rc03 [November 16, 2014]
+  Added "-D_CRT_SECURE_NO_WARNINGS" to CFLAGS in scripts/makefile.vcwin32.
+  Removed the obsolete $ARCH variable from scripts/makefile.darwin.
+
+Version 1.6.15 [November 20, 2014]
+  No changes.
+
+Version 1.6.16beta01 [December 14, 2014]
+  Added ".align 2" to arm/filter_neon.S to support old GAS assemblers that
+    don't do alignment correctly.
+  Revised Makefile.am and scripts/symbols.dfn to work with MinGW/MSYS
+    (Bob Friesenhahn).
+
+Version 1.6.16beta02 [December 15, 2014]
+  Revised Makefile.am and scripts/*.dfn again to work with MinGW/MSYS;
+    renamed scripts/*.dfn to scripts/*.c (John Bowler).
+
+Version 1.6.16beta03 [December 21, 2014]
+  Quiet a "comparison always true" warning in pngstest.c (John Bowler).
+
+Version 1.6.16rc01 [December 21, 2014]
+  Restored a test on width that was removed from png.c at libpng-1.6.9
+    (Bug report by Alex Eubanks, CVE-2015-0973).
+
+Version 1.6.16rc02 [December 21, 2014]
+  Undid the update to pngrutil.c in 1.6.16rc01.
+
+Version 1.6.16rc03 [December 21, 2014]
+  Fixed an overflow in png_combine_row() with very wide interlaced images
+    (Bug report and fix by John Bowler, CVE-2014-9495).
+
+Version 1.6.16 [December 22, 2014]
+  No changes.
+
+Version 1.6.17beta01 [January 29, 2015]
+  Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h
+  Corrected the width limit calculation in png_check_IHDR().
+  Removed user limits from pngfix. Also pass NULL pointers to
+    png_read_row to skip the unnecessary row de-interlace stuff.
+  Added testing of png_set_packing() to pngvalid.c
+  Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
+  Implement previously untested cases of libpng transforms in pngvalid.c
+  Fixed byte order in png_do_read_filler() with 16-bit input. Previously
+    the high and low bytes of the filler, from png_set_filler() or from
+    png_set_add_alpha(), were read in the wrong order.
+  Made the check for out-of-range values in png_set_tRNS() detect
+    values that are exactly 2^bit_depth, and work on 16-bit platforms.
+  Merged some parts of libpng-1.6.17beta01 and libpng-1.7.0beta47.
+  Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and
+    pngset.c to avoid warnings about dead code.
+  Added "& 0xff" to many instances of expressions that are typecast
+    to (png_byte), to avoid Coverity warnings.
+
+Version 1.6.17beta02 [February 7, 2015]
+  Work around one more Coverity-scan dead-code warning.
+  Do not build png_product2() when it is unused.
+
+Version 1.6.17beta03 [February 17, 2015]
+  Display user limits in the output from pngtest.
+  Eliminated the PNG_SAFE_LIMITS macro and restored the 1-million-column
+    and 1-million-row default limits in pnglibconf.dfa, that can be reset
+    by the user at build time or run time.  This provides a more robust
+    defense against DOS and as-yet undiscovered overflows.
+
+Version 1.6.17beta04 [February 21, 2015]
+  Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
+  Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
+  Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
+
+Version 1.6.17beta05 [February 25, 2015]
+  Restored compiling of png_reciprocal2 with PNG_NO_16BIT.
+
+Version 1.6.17beta06 [February 27, 2015]
+  Moved png_set_filter() prototype into a PNG_WRITE_SUPPORTED block
+    of png.h.
+  Avoid runtime checks when converting integer to png_byte with
+    Visual Studio (Sergey Kosarevsky)
+
+Version 1.6.17rc01 [March 4, 2015]
+  No changes.
+
+Version 1.6.17rc02 [March 9, 2015]
+  Removed some comments that the configure script did not handle
+    properly from scripts/pnglibconf.dfa and pnglibconf.h.prebuilt.
+  Free the unknown_chunks structure even when it contains no data.
+
+Version 1.6.17rc03 [March 12, 2015]
+  Updated CMakeLists.txt to add OSX framework, change YES/NO to ON/OFF
+    for consistency, and remove some useless tests (Alexey Petruchik).
+
+Version 1.6.17rc04 [March 16, 2015]
+  Remove pnglibconf.h, pnglibconf.c, and pnglibconf.out instead of
+    pnglibconf.* in "make clean" (Cosmin).
+  Fix bug in calculation of maxbits, in png_write_sBIT, introduced
+    in libpng-1.6.17beta01 (John Bowler).
+
+Version 1.6.17rc05 [March 21, 2015]
+  Define PNG_FILTER_* and PNG_FILTER_VALUE_* in png.h even when WRITE
+    is not supported (John Bowler).  This fixes an error introduced in
+    libpng-1.6.17beta06.
+  Reverted "& 0xff" additions of version 1.6.17beta01. Libpng passes
+    the Coverity scan without them.
+
+Version 1.6.17rc06 [March 23, 2015]
+  Remove pnglibconf.dfn and pnglibconf.pre with "make clean".
+  Reformatted some "&0xff" instances to "& 0xff".
+  Fixed simplified 8-bit-linear to sRGB alpha. The calculated alpha
+    value was wrong.  It's not clear if this affected the final stored
+    value; in the obvious code path the upper and lower 8-bits of the
+    alpha value were identical and the alpha was truncated to 8-bits
+    rather than dividing by 257 (John Bowler).
+
+Version 1.6.17 [March 26, 2015]
+  No changes.
+
+Version 1.6.18beta01 [April 1, 2015]
+  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
+    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+    bug report by Andrew Church).
+  Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c.  This
+    fixes some arithmetic errors that caused some tests to fail on
+    some 32-bit platforms (Bug reports by Peter Breitenlohner [i686]
+    and Petr Gajdos [i586]).
+
+Version 1.6.18beta02 [April 26, 2015]
+  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
+    (Bug report by Viktor Szakats).
+
+Version 1.6.18beta03 [May 6, 2015]
+  Replaced "unexpected" with an integer (0xabadca11) in pngset.c
+    where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1.
+  Added contrib/examples/simpleover.c, to demonstrate how to handle
+    alpha compositing of multiple images, using the "simplified API"
+    and an example PNG generation tool, contrib/examples/genpng.c
+    (John Bowler).
+
+Version 1.6.18beta04 [May 20, 2015]
+  PNG_RELEASE_BUILD replaces tests where the code depended on the build base
+    type and can be defined on the command line, allowing testing in beta
+    builds (John Bowler).
+  Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c PNG_DEBUG builds.
+  Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
+    report from Christopher Ferris).
+
+Version 1.6.18beta05 [May 31, 2015]
+  Backport filter selection code from libpng-1.7.0beta51, to combine
+    sub_row, up_row, avg_row, and paeth_row into try_row and tst_row.
+  Changed png_voidcast(), etc., to voidcast(), etc., in contrib/tools/pngfix.c
+    to avoid confusion with the libpng private macros.
+  Fixed old cut&paste bug in the weighted filter selection code in
+    pngwutil.c, introduced in libpng-0.95, March 1997.
+
+Version 1.6.18beta06 [June 1, 2015]
+  Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the
+    compiled library size. It never worked properly and as far as we can
+    tell, no one uses it. The png_set_filter_heuristics() and
+    png_set_filter_heuristics_fixed() APIs are retained but deprecated
+    and do nothing.
+
+Version 1.6.18beta07 [June 6, 2015]
+  Removed non-working progressive reader 'skip' function. This
+    function has apparently never been used. It was implemented
+    to support back-door modification of png_struct in libpng-1.4.x
+    but (because it does nothing and cannot do anything) was apparently
+    never tested (John Bowler).
+  Fixed cexcept.h in which GCC 5 now reports that one of the auto
+    variables in the Try macro needs to be volatile to prevent value
+    being lost over the setjmp (John Bowler).
+  Fixed NO_WRITE_FILTER and -Wconversion build breaks (John Bowler).
+  Fix g++ build breaks (John Bowler).
+  Quieted some Coverity issues in pngfix.c, png-fix-itxt.c, pngvalid.c,
+    pngstest.c, and pngimage.c. Most seem harmless, but png-fix-itxt
+    would only work with iTXt chunks with length 255 or less.
+  Added #ifdef's to contrib/examples programs so people don't try
+    to compile them without the minimum required support enabled
+    (suggested by Flavio Medeiros).
+
+Version 1.6.18beta08 [June 30, 2015]
+  Eliminated the final two Coverity defects (insecure temporary file
+    handling in contrib/libtests/pngstest.c; possible overflow of
+    unsigned char in contrib/tools/png-fix-itxt.c). To use the "secure"
+    file handling, define PNG_USE_MKSTEMP, otherwise "tmpfile()" will
+    be used.
+  Removed some unused WEIGHTED_FILTER macros from png.h and pngstruct.h
+
+Version 1.6.18beta09 [July 5, 2015]
+  Removed some useless typecasts from contrib/tools/png-fix-itxt.c
+  Fixed a new signed-unsigned comparison in pngrtran.c (Max Stepin).
+  Replaced arbitrary use of 'extern' with #define PNG_LINKAGE_*.  To
+    preserve API compatibility, the new defines all default to "extern"
+    (requested by Jan Nijtmans).
+
+Version 1.6.18rc01 [July 9, 2015]
+  Belatedly added Mans Rullgard and James Yu to the list of Contributing
+    Authors.
+
+Version 1.6.18rc02 [July 12, 2015]
+  Restored unused FILTER_HEURISTIC macros removed at libpng-1.6.18beta08
+    to png.h to avoid compatibility warnings.
+
+Version 1.6.18rc03 [July 15, 2015]
+  Minor changes to the man page
+
+Version 1.6.18 [July 23, 2015]
+  No changes.
+
+Version 1.6.19beta01 [July 30, 2015]
+  Updated obsolete information about the simplified API macros in the
+    manual pages (Bug report by Arc Riley).
+  Avoid potentially dereferencing NULL info_ptr in png_info_init_3().
+  Rearranged png.h to put the major sections in the same order as
+    in libpng17.
+  Eliminated unused PNG_COST_SHIFT, PNG_WEIGHT_SHIFT, PNG_COST_FACTOR, and
+    PNG_WEIGHT_FACTOR macros.
+  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
+    (Bug report by Viktor Szakats).  Several warnings remain and are
+    unavoidable, where we test for overflow.
+  Fixed potential leak of png_pixels in contrib/pngminus/pnm2png.c
+  Fixed uninitialized variable in contrib/gregbook/rpng2-x.c
+
+Version 1.6.19beta02 [August 19, 2015]
+  Moved config.h.in~ from the "libpng_autotools_files" list to the
+    "libpng_autotools_extra" list in autogen.sh because it was causing a
+    false positive for missing files (bug report by Robert C. Seacord).
+  Removed unreachable "break" statements in png.c, pngread.c, and pngrtran.c
+    to suppress clang warnings (Bug report by Viktor Szakats).
+  Fixed some bad links in the man page.
+  Changed "n bit" to "n-bit" in comments.
+  Added signed/unsigned 16-bit safety net. This removes the dubious
+    0x8000 flag definitions on 16-bit systems. They aren't supported
+    yet the defs *probably* work, however it seems much safer to do this
+    and be advised if anyone, contrary to advice, is building libpng 1.6
+    on a 16-bit system. It also adds back various switch default clauses
+    for GCC; GCC errors out if they are not present (with an appropriately
+    high level of warnings).
+  Safely convert num_bytes to a png_byte in png_set_sig_bytes() (Robert
+    Seacord).
+  Fixed the recently reported 1's complement security issue by replacing
+    the value that is illegal in the PNG spec, in both signed and unsigned
+    values, with 0. Illegal unsigned values (anything greater than or equal
+    to  0x80000000) can still pass through, but since these are not illegal
+    in ANSI-C (unlike 0x80000000 in the signed case) the checking that
+    occurs later can catch them (John Bowler).
+
+Version 1.6.19beta03 [September 26, 2015]
+  Fixed png_save_int_32 when int is not 2's complement (John Bowler).
+  Updated libpng16 with all the recent test changes from libpng17,
+    including changes to pngvalid.c to ensure that the original,
+    distributed, version of contrib/visupng/cexcept.h can be used
+    (John Bowler).
+  pngvalid contains the correction to the use of SAVE/STORE_
+    UNKNOWN_CHUNKS; a bug revealed by changes in libpng 1.7. More
+    tests contain the --strict option to detect warnings and the
+    pngvalid-standard test has been corrected so that it does not
+    turn on progressive-read. There is a separate test which does
+    that. (John Bowler)
+  Also made some signed/unsigned fixes.
+  Make pngstest error limits version specific. Splitting the machine
+    generated error structs out to a file allows the values to be updated
+    without changing pngstest.c itself. Since libpng 1.6 and 1.7 have
+    slightly different error limits this simplifies maintenance. The
+    makepngs.sh script has also been updated to more accurately reflect
+    current problems in libpng 1.7 (John Bowler).
+  Incorporated new test PNG files into make check.  tests/pngstest-*
+    are changed so that the new test files are divided into 8 groups by
+    gamma and alpha channel.  These tests have considerably better code
+    and pixel-value coverage than contrib/pngsuite; however,coverage is
+    still incomplete (John Bowler).
+  Removed the '--strict' in 1.6 because of the double-gamma-correction
+    warning, updated pngstest-errors.h for the errors detected with the
+    new contrib/testspngs PNG test files (John Bowler).
+
+Version 1.6.19beta04 [October 15, 2015]
+  Worked around rgb-to-gray issues in libpng 1.6.  The previous
+    attempts to ignore the errors in the code aren't quite enough to
+    deal with the 'channel selection' encoding added to libpng 1.7; abort.
+    pngvalid.c is changed to drop this encoding in prior versions.
+  Fixed 'pow' macros in pngvalid.c. It is legal for 'pow' to be a
+    macro, therefore the argument list cannot contain preprocessing
+    directives.  Make sure pow is a function where this happens. This is
+    a minimal safe fix, the issue only arises in non-performance-critical
+    code (bug report by Curtis Leach, fix by John Bowler).
+  Added sPLT support to pngtest.c
+
+Version 1.6.19rc01 [October 23, 2015]
+  No changes.
+
+Version 1.6.19rc02 [October 31, 2015]
+  Prevent setting or writing over-length PLTE chunk (Cosmin Truta).
+  Silently truncate over-length PLTE chunk while reading.
+  Libpng incorrectly calculated the output rowbytes when the application
+    decreased either the number of channels or the bit depth (or both) in
+    a user transform.  This was safe; libpng overallocated buffer space
+   (potentially by quite a lot; up to 4 times the amount required) but,
+   from 1.5.4 on, resulted in a png_error (John Bowler).
+
+Version 1.6.19rc03 [November 3, 2015]
+  Fixed some inconsequential cut-and-paste typos in png_set_cHRM_XYZ_fixed().
+  Clarified COPYRIGHT information to state explicitly that versions
+    are derived from previous versions.
+  Removed much of the long list of previous versions from png.h and
+    libpng.3.
+
+Version 1.6.19rc04 [November 5, 2015]
+  Fixed new bug with CRC error after reading an over-length palette
+    (bug report by Cosmin Truta) (CVE-2015-8126).
+
+Version 1.6.19 [November 12, 2015]
+  Cleaned up coding style in png_handle_PLTE().
+
+Version 1.6.20beta01 [November 20, 2015]
+  Avoid potential pointer overflow/underflow in png_handle_sPLT() and
+    png_handle_pCAL() (Bug report by John Regehr).
+
+Version 1.6.20beta02 [November 23, 2015]
+  Fixed incorrect implementation of png_set_PLTE() that uses png_ptr
+    not info_ptr, that left png_set_PLTE() open to the CVE-2015-8126
+    vulnerability.  Fixes CVE-2015-8472.
+
+Version 1.6.20beta03 [November 24, 2015]
+  Backported tests from libpng-1.7.0beta69.
+
+Version 1.6.20rc01 [November 26, 2015]
+  Fixed an error in handling of bad zlib CMINFO field in pngfix, found by
+    American Fuzzy Lop, reported by Brian Carpenter.  inflate() doesn't
+    immediately fault a bad CMINFO field; instead a 'too far back' error
+    happens later (at least some times).  pngfix failed to limit CMINFO to
+    the allowed values but then assumed that window_bits was in range,
+    triggering an assert. The bug is mostly harmless; the PNG file cannot
+    be fixed.
+
+Version 1.6.20rc02 [November 29, 2015]
+  In libpng 1.6 zlib initialization was changed to use the window size
+    in the zlib stream, not a fixed value. This causes some invalid images,
+    where CINFO is too large, to display 'correctly' if the rest of the
+    data is valid.  This provides a workaround for zlib versions where the
+    error arises (ones that support the API change to use the window size
+    in the stream).
+
+Version 1.6.20 [December 3, 2015]
+  No changes.
+
+Version 1.6.21beta01 [December 11, 2015]
+  Fixed syntax "$(command)" in tests/pngstest that some shells other than
+    bash could not parse (Bug report by Nelson Beebe). Use `command` instead.
+
+Version 1.6.21beta02 [December 14, 2015]
+  Moved png_check_keyword() from pngwutil.c to pngset.c
+  Removed LE/BE dependencies in pngvalid, to 'fix' the current problem
+    in the BigEndian tests by not testing it, making the BE code the same
+    as the LE version.
+  Fixes to pngvalid for various reduced build configurations (eliminate unused
+    statics) and a fix for the case in rgb_to_gray when the digitize option
+    reduces graylo to 0, producing a large error.
+
+Version 1.6.21beta03 [December 18, 2015]
+  Widened the 'limit' check on the internally calculated error limits in
+    the 'DIGITIZE' case (the code used prior to 1.7 for rgb_to_gray error
+    checks) and changed the check to only operate in non-release builds
+    (base build type not RC or RELEASE.)
+  Fixed undefined behavior in pngvalid.c, undefined because
+    (png_byte) << shift is undefined if it changes the signed bit
+    (because png_byte is promoted to int). The libpng exported functions
+    png_get_uint_32 and png_get_uint_16 handle this. (Bug reported by
+    David Drysdale as a result of reports from UBSAN in clang 3.8).
+  This changes pngvalid to use BE random numbers; this used to produce
+    errors but these should not be fixed as a result of the previous changes.
+
+Version 1.6.21rc01 [January 4, 2016]
+  In projects/vstudio, combined readme.txt and WARNING into README.txt
+
+Version 1.6.21rc02 [January 7, 2016]
+  Relocated assert() in contrib/tools/pngfix.c, bug found by American
+    Fuzzy Lop, reported by Brian Carpenter.
+  Marked 'limit' UNUSED in transform_range_check().  This only affects
+    release builds.
+
+Version 1.6.21 [January 15, 2016]
+  Worked around a false-positive Coverity issue in pngvalid.c.
+
+Version 1.6.22beta01 [January 23, 2016]
+  Changed PNG_USE_MKSTEMP to __COVERITY__ to select alternate
+    "tmpfile()" implementation in contrib/libtests/pngstest.c
+  Fixed NO_STDIO build of pngunknown.c to skip calling png_init_io()
+    if there is no stdio.h support.
+  Added a png_image_write_to_memory() API and a number of assist macros
+    to allow an application that uses the simplified API write to bypass
+    stdio and write directly to memory.
+  Added some warnings (png.h) and some check code to detect *possible*
+    overflow in the ROW_STRIDE and simplified image SIZE macros.  This
+    disallows image width/height/format that *might* overflow.  This is
+    a quiet API change that limits in-memory image size (uncompressed) to
+    less than 4GByte and image row size (stride) to less than 2GByte.
+  Revised workaround for false-positive Coverity issue in pngvalid.c.
+
+Version 1.6.22beta02 [February 8, 2016]
+  Only use exit(77) in configure builds.
+  Corrected error in PNG_IMAGE_PNG_SIZE_MAX. This new macro underreported
+    the palette size because it failed to take into account that the memory
+    palette has to be expanded to full RGB when it is written to PNG.
+  Updated CMakeLists.txt, added supporting scripts/gen*.cmake.in
+    and test.cmake.in (Roger Leigh).
+  Relaxed limit checks on gamma values in pngrtran.c. As suggested in
+    the comments gamma values outside the range currently permitted
+    by png_set_alpha_mode are useful for HDR data encoding.  These values
+    are already permitted by png_set_gamma so it is reasonable caution to
+    extend the png_set_alpha_mode range as HDR imaging systems are starting
+    to emerge.
+
+Version 1.6.22beta03 [March 9, 2016]
+  Added a common-law trademark notice and export control information
+    to the LICENSE file, png.h, and the man page.
+  Restored "& 0xff" in png_save_uint_16() and png_save_uint_32() that
+    were accidentally removed from libpng-1.6.17.
+  Changed PNG_INFO_cHNK and PNG_FREE_cHNK from 0xnnnn to 0xnnnnU in png.h
+    (Robert C. Seacord).
+  Removed dubious "#if INT_MAX" test from png.h that was added to
+    libpng-1.6.19beta02 (John Bowler).
+  Add ${INCLUDES} in scripts/genout.cmake.in (Bug report by Nixon Kwok).
+  Updated LICENSE to say files in the contrib directory are not
+    necessarily under the libpng license, and that some makefiles have
+    other copyright owners.
+  Added INTEL-SSE2 support (Mike Klein and Matt Sarett, Google, Inc.).
+  Made contrib/libtests/timepng more robust.  The code no longer gives
+    up/fails on invalid PNG data, it just skips it (with error messages).
+    The code no longer fails on PNG files with data beyond IEND.  Options
+    exist to use png_read_png (reading the whole image, not by row) and, in
+    that case, to apply any of the supported transforms.  This makes for
+    more realistic testing; the decoded data actually gets used in a
+    meaningful fashion (John Bowler).
+  Fixed some misleading indentation (Krishnaraj Bhat).
+
+Version 1.6.22beta04 [April 5, 2016]
+  Force GCC compilation to C89 if needed (Dagobert Michelsen).
+  SSE filter speed improvements for bpp=3:
+    memcpy-free implementations of load3() / store3().
+    call load3() only when needed at the end of a scanline.
+
+Version 1.6.22beta05 [April 27, 2016]
+  Added PNG_FAST_FILTERS macro (defined as
+    PNG_FILTER_NONE|PNG_FILTER_SUB|PNG_FILTER_UP).
+  Various fixes for contrib/libtests/timepng.c
+  Moved INTEL-SSE code from pngpriv.h into contrib/intel/intel_sse.patch.
+  Fixed typo (missing underscore) in #define PNG_READ_16_TO_8_SUPPORTED
+    (Bug report by Y.Ohashik).
+
+Version 1.6.22beta06 [May 5, 2016]
+  Rebased contrib/intel_sse.patch.
+  Quieted two Coverity issues in contrib/libtests/timepng.c.
+  Fixed issues with scripts/genout.cmake.in (David Capello, Nixon Kwok):
+    Added support to use multiple directories in ZLIBINCDIR variable,
+    Fixed CMAKE_C_FLAGS with multiple values when genout is compiled on MSVC,
+    Fixed pnglibconf.c compilation on OS X including the sysroot path.
+
+Version 1.6.22rc01 [May 14, 2016]
+  No changes.
+
+Version 1.6.22rc02 [May 16, 2016]
+  Removed contrib/timepng from default build; it does not build on platforms
+    that don't supply clock_gettime().
+
+Version 1.6.22rc03 [May 17, 2016]
+  Restored contrib/timepng to default build but check for the presence
+    of clock_gettime() in configure.ac and Makefile.am.
+
+Version 1.6.22 [May 26, 2016]
+  No changes.
+
+Version 1.6.23beta01 [May 29, 2016]
+  Stop a potential memory leak in png_set_tRNS() (Bug report by Ted Ying).
+  Fixed the progressive reader to handle empty first IDAT chunk properly
+    (patch by Timothy Nikkel).  This bug was introduced in libpng-1.6.0 and
+    only affected the libpng16 branch.
+  Added tests in pngvalid.c to check zero-length IDAT chunks in various
+    positions.  Fixed the sequential reader to handle these more robustly
+    (John Bowler).
+
+Version 1.6.23rc01 [June 2, 2016]
+  Corrected progressive read input buffer in pngvalid.c. The previous version
+    the code invariably passed just one byte at a time to libpng.  The intent
+    was to pass a random number of bytes in the range 0..511.
+  Moved sse2 prototype from pngpriv.h to contrib/intel/intel_sse.patch.
+  Added missing ")" in pngerror.c (Matt Sarrett).
+
+Version 1.6.23rc02 [June 4, 2016]
+  Fixed undefined behavior in png_push_save_buffer(). Do not call
+    memcpy() with a null source, even if count is zero (Leon Scroggins III).
+
+Version 1.6.23 [June 9, 2016]
+  Fixed bad link to RFC2083 in png.5 (Nikola Forro).
+
+Version 1.6.24beta01 [June 11, 2016]
+  Avoid potential overflow of the PNG_IMAGE_SIZE macro.  This macro
+    is not used within libpng, but is used in some of the examples.
+
+Version 1.6.24beta02 [June 23, 2016]
+  Correct filter heuristic overflow handling. This was broken when the
+    write filter code was moved out-of-line; if there is a single filter and
+    the heuristic sum overflows the calculation of the filtered line is not
+    completed.  In versions prior to 1.6 the code was duplicated in-line
+    and the check not performed, so the filter operation completed; however,
+    in the multi-filter case where the sum is performed the 'none' filter would
+    be selected if all the sums overflowed, even if it wasn't in the filter
+    list.  The fix to the first problem is simply to provide PNG_SIZE_MAX as
+    the current lmins sum value; this means the sum can never exceed it and
+    overflows silently.  A reasonable compiler that does choose to inline
+    the code will simply eliminate the sum check.
+  The fix to the second problem is to use high precision arithmetic (this is
+    implemented in 1.7), however a simple safe fix here is to chose the lowest
+    numbered filter in the list from png_set_filter (this only works if the
+    first problem is also fixed) (John Bowler).
+  Use a more efficient absolute value calculation on SSE2 (Matthieu Darbois).
+  Fixed the case where PNG_IMAGE_BUFFER_SIZE can overflow in the application
+    as a result of the application using an increased 'row_stride'; previously
+    png_image_finish_read only checked for overflow on the base calculation of
+    components.  (I.e. it checked for overflow of a 32-bit number on the total
+    number of pixel components in the output format, not the possibly padded row
+    length and not the number of bytes, which for linear formats is twice the
+    number of components.)
+  MSVC does not like '-(unsigned)', so replaced it with 0U-(unsigned)
+  MSVC does not like (uInt) = -(unsigned) (i.e. as an initializer), unless
+    the conversion is explicitly invoked by a cast.
+  Put the SKIP definition in the correct place. It needs to come after the
+    png.h include (see all the other .c files in contrib/libtests) because it
+    depends on PNG_LIBPNG_VER.
+  Removed the three compile warning options from the individual project
+    files into the zlib.props globals.  It increases the warning level from 4
+    to All and adds a list of the warnings that need to be turned off.  This is
+    semi-documentary; the intent is to tell libpng users which warnings have
+    been examined and judged non-fixable at present.  The warning about
+    structure padding is fixable, but it would be a significant change (moving
+    structure members around).
+
+Version 1.6.24beta03 [July 4, 2016]
+  Optimized absolute value calculation in filter selection, similar to
+    code in the PAETH decoder in pngrutil.c. Build with PNG_USE_ABS to
+    use this.
+  Added pngcp to the build together with a pngcp.dfa configuration test.
+  Added high resolution timing to pngcp.
+  Added "Common linking failures" section to INSTALL.
+  Relocated misplaced #endif in png.c sRGB profile checking.
+  Fixed two Coverity issues in pngcp.c.
+
+Version 1.6.24beta04 [July 8, 2016]
+  Avoid filter-selection heuristic sum calculations in cases where only one
+    filter is a candidate for selection. This trades off code size (added
+    private png_setup_*_row_only() functions) for speed.
+
+Version 1.6.24beta05 [July 13, 2016]
+  Fixed some indentation to comply with our coding style.
+  Added contrib/tools/reindent.
+
+Version 1.6.24beta06 [July 18, 2016]
+  Fixed more indentation to comply with our coding style.
+  Eliminated unnecessary tests of boolean png_isaligned() vs 0.
+
+Version 1.6.24rc01 [July 25, 2016]
+  No changes.
+
+Version 1.6.24rc02 [August 1, 2016]
+  Conditionally compile SSE2 headers in contrib/intel/intel_sse.patch
+  Conditionally compile png_decompress_chunk().
+
+Version 1.6.24rc03 [August 2, 2016]
+  Conditionally compile ARM_NEON headers in pngpriv.h
+  Updated contrib/intel/intel_sse.patch
+
+Version 1.6.24[August 4, 2016]
+  No changes.
+
+Version 1.6.25beta01 [August 12, 2016]
+  Reject oversized iCCP profile immediately.
+  Cleaned up PNG_DEBUG compile of pngtest.c.
+  Conditionally compile png_inflate().
+
+Version 1.6.25beta02 [August 18, 2016]
+  Don't install pngcp; it conflicts with pngcp in the pngtools package.
+  Minor editing of INSTALL, (whitespace, added copyright line)
+
+Version 1.6.25rc01 [August 24, 2016]
+  No changes.
+
+Version 1.6.25rc02 [August 29, 2016]
+  Added MIPS support (Mandar Sahastrabuddhe <Mandar.Sahastrabuddhe@imgtec.com>).
+  Only the UP filter is currently implemented.
+
+Version 1.6.25rc03 [August 29, 2016]
+  Rebased contrib/intel/intel_sse.patch after the MIPS implementation.
+
+Version 1.6.25rc04 [August 30, 2016]
+  Added MIPS support for SUB, AVG, and PAETH filters (Mandar Sahastrabuddhe).
+
+Version 1.6.25rc05 [August 30, 2016]
+  Rebased contrib/intel/intel_sse.patch after the MIPS implementation update..
+
+Version 1.6.25 [September 1, 2016]
+  No changes.
+
+Version 1.6.26beta01 [September 26, 2016]
+  Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
+    bugfix by John Bowler).
+  Do not issue a png_error() on read in png_set_pCAL() because png_handle_pCAL
+    has allocated memory that libpng needs to free.
+  Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c
+  Issue a png_benign_error instead of a png_error on ADLER32 mismatch
+    while decoding compressed data chunks.
+  Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngpriv.h, pngstruct.h, and
+    pngrutil.c.
+  If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
+    ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
+  Issue png_benign_error() on ADLER32 checksum mismatch instead of png_error().
+  Add tests/badcrc.png and tests/badadler.png to tests/pngtest.
+  Merged pngtest.c with libpng-1.7.0beta84/pngtest.c
+
+Version 1.6.26beta02 [October 1, 2016]
+  Updated the documentation about CRC and ADLER32 handling.
+  Quieted 117 warnings from clang-3.8 in pngtrans.c, pngread.c,
+     pngwrite.c, pngunknown.c, and pngvalid.c.
+  Quieted 58 (out of 144) -Wconversion compiler warnings by changing
+    flag definitions in pngpriv.h from 0xnnnn to 0xnnnnU and trivial changes
+    in png.c, pngread.c, and pngwutil.c.
+
+Version 1.6.26beta03 [October 2, 2016]
+  Removed contrib/libtests/*.orig and *.rej that slipped into the tarballs.
+  Quieted the 86 remaining -Wconversion compiler warnings by
+    revising the png_isaligned() macro and trivial changes in png.c,
+    pngerror.c, pngget.c, pngmem.c, pngset.c, pngrtran.c, pngrutil.c,
+    pngwtran.c, pngwrite.c, and pngwutil.c.
+
+Version 1.6.26beta04 [October 3, 2016]
+  Quieted (bogus?) clang warnings about "absolute value has no effect"
+    when PNG_USE_ABS is defined.
+  Fixed offsets in contrib/intel/intel_sse.patch
+
+Version 1.6.26beta05 [October 6, 2016]
+  Changed integer constant 4294967294 to unsigned 4294967294U in pngconf.h
+    to avoid a signed/unsigned compare in the preprocessor.
+
+Version 1.6.26beta06 [October 7, 2016]
+  Use zlib-1.2.8.1 inflateValidate() instead of inflateReset2() to
+    optionally avoid ADLER32 evaluation.
+
+Version 1.6.26rc01 [October 12, 2016]
+  No changes.
+
+Version 1.6.26 [October 20, 2016]
+  Cosmetic change, "ptr != 0" to "ptr != NULL" in png.c and pngrutil.c
+  Despammed email addresses (replaced "@" with " at ").
+
+Version 1.6.27beta01 [November 2, 2016]
+  Restrict the new ADLER32-skipping to IDAT chunks.  It broke iCCP chunk
+    handling: an erroneous iCCP chunk would throw a png_error and reject the
+    entire PNG image instead of rejecting just the iCCP chunk with a warning,
+    if built with zlib-1.2.8.1.
+
+Version 1.6.27rc01 [December 27, 2016]
+  Control ADLER32 checking with new PNG_IGNORE_ADLER32 option. Fixes
+    an endless loop when handling erroneous ADLER32 checksums; bug
+    introduced in libpng-1.6.26.
+  Removed the use of a macro containing the pre-processor 'defined'
+    operator.  It is unclear whether this is valid; a macro that
+    "generates" 'defined' is not permitted, but the use of the word
+    "generates" within the C90 standard seems to imply more than simple
+    substitution of an expression itself containing a well-formed defined
+    operation.
+  Added ARM support to CMakeLists.txt (Andreas Franek).
+
+Version 1.6.27 [December 29, 2016]
+  Fixed a potential null pointer dereference in png_set_text_2() (bug report
+    and patch by Patrick Keshishian, CVE-2016-10087).
+
+Version 1.6.28rc01 [January 3, 2017]
+  Fixed arm/aarch64 detection in CMakeLists.txt (Gianfranco Costamagna).
+  Added option to Cmake build allowing a custom location of zlib to be
+    specified in a scenario where libpng is being built as a subproject
+    alongside zlib by another project (Sam Serrels).
+  Changed png_ptr->options from a png_byte to png_uint_32, to accommodate
+    up to 16 options.
+
+Version 1.6.28rc02 [January 4, 2017]
+  Added "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
+  Moved SSE2 optimization code into the main libpng source directory.
+    Configure libpng with "configure --enable-intel-sse" or compile
+    libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
+
+Version 1.6.28rc03 [January 4, 2017]
+  Backed out the SSE optimization and last CMakeLists.txt to allow time for QA.
+
+Version 1.6.28 [January 5, 2017]
+  No changes.
+
+Version 1.6.29beta01 [January 12, 2017]
+  Readded "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
+  Moved SSE2 optimization code into the main libpng source directory.
+    Configure libpng with "configure --enable-intel-sse" or compile
+    libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
+  Simplified conditional compilation in pngvalid.c, for AIX (Michael Felt).
+
+Version 1.6.29beta02 [February 22, 2017]
+  Avoid conditional directives that break statements in pngrutil.c (Romero
+    Malaquias)
+  The contrib/examples/pngtopng.c recovery code was in the wrong "if"
+    branches; the comments were correct.
+  Added code for PowerPC VSX optimisation (Vadim Barkov).
+
+Version 1.6.29beta03 [March 1, 2017]
+  Avoid potential overflow of shift operations in png_do_expand() (Aaron Boxer).
+  Change test ZLIB_VERNUM >= 0x1281 to ZLIB_VERNUM >= 0x1290 in pngrutil.c
+    because Solaris 11 distributes zlib-1.2.8.f that is older than 1.2.8.1,
+    as suggested in zlib FAQ, item 24.
+  Suppress clang warnings about implicit sign changes in png.c
+
+Version 1.6.29 [March 16, 2017]
+  No changes.
+
+Version 1.6.30beta01 [April 1, 2017]
+  Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in
+    makefile.linux and makefile.solaris-x86 (Cosmin).
+  Revised documentation of png_get_error_ptr() in the libpng manual.
+  Silence clang -Wcomma and const drop warnings (Viktor Szakats).
+  Update Sourceforge URLs in documentation (https instead of http).
+
+Version 1.6.30beta02 [April 22, 2017]
+  Document need to check for integer overflow when allocating a pixel
+    buffer for multiple rows in contrib/gregbook, contrib/pngminus,
+    example.c, and in the manual (suggested by Jaeseung Choi). This
+    is similar to the bug reported against pngquant in CVE-2016-5735.
+  Removed reference to the obsolete PNG_SAFE_LIMITS macro in the documentation.
+
+Version 1.6.30beta03 [May 22, 2017]
+  Check for integer overflow in contrib/visupng and contrib/tools/genpng.
+  Do not double evaluate CMAKE_SYSTEM_PROCESSOR in CMakeLists.txt.
+  Test CMAKE_HOST_WIN32 instead of WIN32 in CMakeLists.txt.
+  Fix some URL in documentation.
+
+Version 1.6.30beta04 [June 7, 2017]
+  Avoid writing an empty IDAT when the last IDAT exactly fills the
+    compression buffer (bug report by Brian Baird). This bug was
+    introduced in libpng-1.6.0.
+
+Version 1.6.30rc01 [June 14, 2017]
+  No changes.
+
+Version 1.6.30rc02 [June 25, 2017]
+  Update copyright year in pnglibconf.h, make ltmain.sh executable.
+  Add a reference to the libpng.download site in README.
+
+Version 1.6.30 [June 28, 2017]
+  No changes.
+
+Version 1.6.31beta01 [July 5, 2017]
+  Guard the definition of _POSIX_SOURCE in pngpriv.h (AIX already defines it;
+    bug report by Michael Felt).
+  Revised pngpriv.h to work around failure to compile arm/filter_neon.S
+    ("typedef" directive is unrecognized by the assembler). The problem
+    was introduced in libpng-1.6.30beta01.
+  Added "Requires: zlib" to libpng.pc.in (Pieter Neerincx).
+  Added special case for FreeBSD in arm/filter_neon.S (Maya Rashish).
+
+Version 1.6.31beta02 [July 8, 2017]
+  Added instructions for disabling hardware optimizations in INSTALL.
+  Added "--enable-hardware-optimizations" configuration flag to enable
+    or disable all hardware optimizations with one flag.
+
+Version 1.6.31beta03 [July 9, 2017]
+  Updated CMakeLists.txt to add INTEL_SSE and MIPS_MSA platforms.
+  Changed "int" to "png_size_t" in intel/filter_sse2.c to prevent
+    possible integer overflow (Bug report by John Bowler).
+  Quieted "declaration after statement" warnings in intel/filter_sse2.c.
+  Added scripts/makefile-linux-opt, which has hardware optimizations enabled.
+
+Version 1.6.31beta04 [July 11, 2017]
+  Removed one of the GCC-7.1.0 'strict-overflow' warnings that result when
+    integers appear on both sides of a compare.  Worked around the others by
+    forcing the strict-overflow setting in the relevant functions to a level
+    where they are not reported (John Bowler).
+  Changed "FALL THROUGH" comments to "FALLTHROUGH" because GCC doesn't like
+    the space.
+  Worked around some C-style casts from (void*) because g++ 5.4.0 objects
+    to them.
+  Increased the buffer size for 'sprint' to pass the gcc 7.1.0 'sprint
+    overflow' check that is on by default with -Wall -Wextra.
+
+Version 1.6.31beta05 [July 13, 2017]
+  Added eXIf chunk support.
+
+Version 1.6.31beta06 [July 17, 2017]
+  Added a minimal eXIf chunk (with Orientation and FocalLengthIn35mmFilm
+    tags) to pngtest.png.
+
+Version 1.6.31beta07 [July 18, 2017]
+  Revised the eXIf chunk in pngtest.png to fix "Bad IFD1 Directory" warning.
+
+Version 1.6.31rc01 [July 19, 2017]
+  No changes.
+
+Version 1.6.31rc02 [July 25, 2017]
+  Fixed typo in example.c (png_free_image should be png_image_free) (Bug
+    report by John Smith)
+
+Version 1.6.31 [July 27, 2017]
+  No changes.
+
+Version 1.6.32beta01 [July 31, 2017]
+  Avoid possible NULL dereference in png_handle_eXIf when benign_errors
+    are allowed. Avoid leaking the input buffer "eXIf_buf".
+  Eliminated png_ptr->num_exif member from pngstruct.h and added num_exif
+    to arguments for png_get_eXIf() and png_set_eXIf().
+  Added calls to png_handle_eXIf(() in pngread.c and png_write_eXIf() in
+    pngwrite.c, and made various other fixes to png_write_eXIf().
+  Changed name of png_get_eXIF and png_set_eXIf() to png_get_eXIf_1() and
+    png_set_eXIf_1(), respectively, to avoid breaking API compatibility
+    with libpng-1.6.31.
+
+Version 1.6.32beta02 [August 1, 2017]
+  Updated contrib/libtests/pngunknown.c with eXIf chunk.
+
+Version 1.6.32beta03 [August 2, 2017]
+  Initialized btoa[] in pngstest.c
+  Stop memory leak when returning from png_handle_eXIf() with an error
+    (Bug report from the OSS-fuzz project).
+
+Version 1.6.32beta04 [August 2, 2017]
+  Replaced local eXIf_buf with info_ptr-eXIf_buf in png_handle_eXIf().
+  Update libpng.3 and libpng-manual.txt about eXIf functions.
+
+Version 1.6.32beta05 [August 2, 2017]
+  Restored png_get_eXIf() and png_set_eXIf() to maintain API compatibility.
+
+Version 1.6.32beta06 [August 2, 2017]
+  Removed png_get_eXIf_1() and png_set_eXIf_1().
+
+Version 1.6.32beta07 [August 3, 2017]
+  Check length of all chunks except IDAT against user limit to fix an
+    OSS-fuzz issue (Fixes CVE-2017-12652).
+
+Version 1.6.32beta08 [August 3, 2017]
+  Check length of IDAT against maximum possible IDAT size, accounting
+    for height, rowbytes, interlacing and zlib/deflate overhead.
+  Restored png_get_eXIf_1() and png_set_eXIf_1(), because strlen(eXIf_buf)
+    does not work (the eXIf chunk data can contain zeroes).
+
+Version 1.6.32beta09 [August 3, 2017]
+  Require cmake-2.8.8 in CMakeLists.txt. Revised symlink creation,
+    no longer using deprecated cmake LOCATION feature (Clifford Yapp).
+  Fixed five-byte error in the calculation of IDAT maximum possible size.
+
+Version 1.6.32beta10 [August 5, 2017]
+  Moved chunk-length check into a png_check_chunk_length() private
+    function (Suggested by Max Stepin).
+  Moved bad pngs from tests to contrib/libtests/crashers
+  Moved testing of bad pngs into a separate tests/pngtest-badpngs script
+  Added the --xfail (expected FAIL) option to pngtest.c. It writes XFAIL
+    in the output but PASS for the libpng test.
+  Require cmake-3.0.2 in CMakeLists.txt (Clifford Yapp).
+  Fix "const" declaration info_ptr argument to png_get_eXIf_1() and the
+    num_exif argument to png_get_eXIf_1() (Github Issue 171).
+
+Version 1.6.32beta11 [August 7, 2017]
+  Added "eXIf" to "chunks_to_ignore[]" in png_set_keep_unknown_chunks().
+  Added huge_IDAT.png and empty_ancillary_chunks.png to testpngs/crashers.
+  Make pngtest --strict, --relax, --xfail options imply -m (multiple).
+  Removed unused chunk_name parameter from png_check_chunk_length().
+  Relocated setting free_me for eXIf data, to stop an OSS-fuzz leak.
+  Initialize profile_header[] in png_handle_iCCP() to fix OSS-fuzz issue.
+  Initialize png_ptr->row_buf[0] to 255 in png_read_row() to fix OSS-fuzz UMR.
+  Attempt to fix a UMR in png_set_text_2() to fix OSS-fuzz issue.
+  Increase minimum zlib stream from 9 to 14 in png_handle_iCCP(), to account
+    for the minimum 'deflate' stream, and relocate the test to a point
+    after the keyword has been read.
+  Check that the eXIf chunk has at least 2 bytes and begins with "II" or "MM".
+
+Version 1.6.32rc01 [August 18, 2017]
+  Added a set of "huge_xxxx_chunk.png" files to contrib/testpngs/crashers,
+    one for each known chunk type, with length = 2GB-1.
+  Check for 0 return from png_get_rowbytes() and added some (size_t) typecasts
+    in contrib/pngminus/*.c to stop some Coverity issues (162705, 162706,
+    and 162707).
+  Renamed chunks in contrib/testpngs/crashers to avoid having files whose
+    names differ only in case; this causes problems with some platforms
+    (github issue #172).
+
+Version 1.6.32rc02 [August 22, 2017]
+  Added contrib/oss-fuzz directory which contains files used by the oss-fuzz
+    project (https://github.com/google/oss-fuzz/tree/master/projects/libpng).
+
+Version 1.6.32 [August 24, 2017]
+  No changes.
+
+Version 1.6.33beta01 [August 28, 2017]
+  Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing
+    parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).
+  Fixed off-by-one error in png_do_check_palette_indexes() (Bug report
+    by Mick P., Source Forge Issue #269).
+
+Version 1.6.33beta02 [September 3, 2017]
+  Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
+    to fix shortlived oss-fuzz issue 3234.
+  Compute a larger limit on IDAT because some applications write a deflate
+    buffer for each row (Bug report by Andrew Church).
+  Use current date (DATE) instead of release-date (RDATE) in last
+    changed date of contrib/oss-fuzz files.
+  Enabled ARM support in CMakeLists.txt (Bernd Kuhls).
+
+Version 1.6.33beta03 [September 14, 2017]
+  Fixed incorrect typecast of some arguments to png_malloc() and
+    png_calloc() that were png_uint_32 instead of png_alloc_size_t
+    (Bug report by "irwir" in Github libpng issue #175).
+  Use pnglibconf.h.prebuilt when building for ANDROID with cmake (Github
+    issue 162, by rcdailey).
+
+Version 1.6.33rc01 [September 20, 2017]
+  Initialize memory allocated by png_inflate to zero, using memset, to
+    stop an oss-fuzz "use of uninitialized value" detection in png_set_text_2()
+    due to truncated iTXt or zTXt chunk.
+  Initialize memory allocated by png_read_buffer to zero, using memset, to
+    stop an oss-fuzz "use of uninitialized value" detection in
+    png_icc_check_tag_table() due to truncated iCCP chunk.
+  Removed a redundant test (suggested by "irwir" in Github issue #180).
+
+Version 1.6.33rc02 [September 23, 2017]
+  Added an interlaced version of each file in contrib/pngsuite.
+  Relocate new memset() call in pngrutil.c.
+  Removed more redundant tests (suggested by "irwir" in Github issue #180).
+  Add support for loading images with associated alpha in the Simplified
+    API (Samuel Williams).
+
+Version 1.6.33 [September 28, 2017]
+  Revert contrib/oss-fuzz/libpng_read_fuzzer.cc to libpng-1.6.32 state.
+  Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
+  Add end_info structure and png_read_end() to the libpng fuzzer.
+
+Version 1.6.34 [September 29, 2017]
+  Removed contrib/pngsuite/i*.png; some of them caused test failures.
+
+Version 1.6.35beta01 [March 6, 2018]
+  Restored 21 of the contrib/pngsuite/i*.png, which do not cause test
+    failures. Placed the remainder in contrib/pngsuite/interlaced/i*.png.
+  Added calls to png_set_*() transforms commonly used by browsers to
+    the fuzzer.
+  Removed some unnecessary brackets in pngrtran.c
+  Fixed miscellaneous typos (Patch by github user "luzpaz").
+  Change "ASM C" to "C ASM" in CMakeLists.txt
+  Fixed incorrect handling of bKGD chunk in sub-8-bit files (Cosmin)
+  Added hardware optimization directories to zip and 7z distributions.
+  Fixed incorrect bitmask for options.
+  Fixed many spelling typos.
+
+Version 1.6.35beta02 [March 28, 2018]
+  Make png_get_iCCP consistent with man page (allow compression-type argument
+  to be NULL, bug report by Lenard Szolnoki).
+
+Version 1.6.35 [July 15, 2018]
+  Replaced the remaining uses of png_size_t with size_t (Cosmin)
+  Fixed the calculation of row_factor in png_check_chunk_length
+    (reported by Thuan Pham in SourceForge issue #278)
+  Added missing parentheses to a macro definition
+    (suggested by "irwir" in GitHub issue #216)
+
+Version 1.6.36 [December 1, 2018]
+  Optimized png_do_expand_palette for ARM processors.
+  Improved performance by around 10-22% on a recent ARM Chromebook.
+    (Contributed by Richard Townsend, ARM Holdings)
+  Fixed manipulation of machine-specific optimization options.
+    (Contributed by Vicki Pfau)
+  Used memcpy instead of manual pointer arithmetic on Intel SSE2.
+    (Contributed by Samuel Williams)
+  Fixed build errors with MSVC on ARM64.
+    (Contributed by Zhijie Liang)
+  Fixed detection of libm in CMakeLists.
+    (Contributed by Cameron Cawley)
+  Fixed incorrect creation of pkg-config file in CMakeLists.
+    (Contributed by Kyle Bentley)
+  Fixed the CMake build on Windows MSYS by avoiding symlinks.
+  Fixed a build warning on OpenBSD.
+    (Contributed by Theo Buehler)
+  Fixed various typos in comments.
+    (Contributed by "luz.paz")
+  Raised the minimum required CMake version from 3.0.2 to 3.1.
+  Removed yet more of the vestigial support for pre-ANSI C compilers.
+  Removed ancient makefiles for ancient systems that have been broken
+    across all previous libpng-1.6.x versions.
+  Removed the Y2K compliance statement and the export control
+    information.
+  Applied various code style and documentation fixes.
+
+Version 1.6.37 [April 14, 2019]
+  Fixed a use-after-free vulnerability (CVE-2019-7317) in png_image_free.
+  Fixed a memory leak in the ARM NEON implementation of png_do_expand_palette.
+  Fixed a memory leak in pngtest.c.
+  Fixed two vulnerabilities (CVE-2018-14048, CVE-2018-14550) in
+    contrib/pngminus; refactor.
+  Changed the license of contrib/pngminus to MIT; refresh makefile and docs.
+    (Contributed by Willem van Schaik)
+  Fixed a typo in the libpng license v2.
+    (Contributed by Miguel Ojeda)
+  Added makefiles for AddressSanitizer-enabled builds.
+  Cleaned up various makefiles.
+
+Version 1.6.38 [September 14, 2022]
+  Added configurations and scripts for continuous integration.
+  Fixed various errors in the handling of tRNS, hIST and eXIf.
+  Implemented many stability improvements across all platforms.
+  Updated the internal documentation.
+
+Version 1.6.39 [November 20, 2022]
+  Changed the error handler of oversized chunks (i.e. larger than
+    PNG_USER_CHUNK_MALLOC_MAX) from png_chunk_error to png_benign_error.
+  Fixed a buffer overflow error in contrib/tools/pngfix.
+  Fixed a memory leak (CVE-2019-6129) in contrib/tools/pngcp.
+  Disabled the ARM Neon optimizations by default in the CMake file,
+    following the default behavior of the configure script.
+  Allowed configure.ac to work with the trunk version of autoconf.
+  Removed the support for "install" targets from the legacy makefiles;
+    removed the obsolete makefile.cegcc.
+  Cleaned up the code and updated the internal documentation.
+
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