ANNOUNCE - third_party/libpng - Git at Google


 Libpng 1.5.3beta08 - May 16, 2011

 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.

 Files available for download:

 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script

    1.5.3beta08.tar.xz (LZMA-compressed, recommended)
    1.5.3beta08.tar.gz
    1.5.3beta08.tar.bz2

 Source files with CRLF line endings (for Windows), without the
 "configure" script

    lp153b08.7z  (LZMA-compressed, recommended)
    lp153b08.zip

 Other information:

    1.5.3beta08-README.txt
    1.5.3beta08-LICENSE.txt

 Changes since the last public release (1.5.2):

 Version 1.5.3beta01 [April 1, 2011]
   Re-initialize the zlib compressor before compressing non-IDAT chunks.
   Added API functions to set parameters for zlib compression of non-IDAT
     chunks.

 Version 1.5.3beta02 [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 clash with the png_jmpbuf macro on some platforms.

 Version 1.5.3beta05 [May 6, 2011]
   Added appropriate feature test macros 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.  _ISOC99_SOURCE is
     defined in pngpriv.h to obtain the ISO C99 snprintf definition, when
     available.
   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.
   Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
     optimization configureable.
   IDAT compression failed if preceded by a compressed text chunk (bug
     introduced in libpng-1.5.3beta01-02).  This was because the attempt to
     reset the zlib stream in png_write_IDAT happened after the first IDAT
     chunk had been deflated - much too late.  In this change internal
     functions were added to claim/release the z_stream and, hopefully, make
     the code more robust.  Also deflateEnd checking is added - previously
     libpng would ignore an error at the end of the stream.

 Version 1.5.3beta06 [May 8, 2011]
   Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
   Implemented premultiplied alpha support: png_set_alpha_mode API

 Version 1.5.3beta07 [May 11, 2011]
   Added expand_16 support to the high level interface.
   Added named value and 'flag' gamma support to png_set_gamma.  Made a minor
     change from the previous (unreleased) ABI/API to hide the exact value used
     for Macs - it's not a good idea to embed this in the ABI!
   Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
     from pngpriv.h to png.h because they must be visible to applications
     that call png_set_unknown_chunks().
   Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
     before IDAT.

 Version 1.5.3beta08 [May 16, 2011]
   Improved "pngvalid --speed" to exclude more of pngvalid from the time.
   Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
   The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
     parameters are supplied by the caller), while in the absence of cHRM
     sRGB/Rec 709 values are still used.
   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

 Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
 to subscribe) or to glennrp at users.sourceforge.net

 Glenn R-P

	Libpng 1.5.3beta08 - May 16, 2011

	This is not intended to be a public release. It will be replaced
	within a few weeks by a public version or by another test version.

	Files available for download:

	Source files with LF line endings (for Unix/Linux) and with a
	"configure" script

	1.5.3beta08.tar.xz (LZMA-compressed, recommended)
	1.5.3beta08.tar.gz
	1.5.3beta08.tar.bz2

	Source files with CRLF line endings (for Windows), without the
	"configure" script

	lp153b08.7z (LZMA-compressed, recommended)
	lp153b08.zip

	Other information:

	1.5.3beta08-README.txt
	1.5.3beta08-LICENSE.txt

	Changes since the last public release (1.5.2):

	Version 1.5.3beta01 [April 1, 2011]
	Re-initialize the zlib compressor before compressing non-IDAT chunks.
	Added API functions to set parameters for zlib compression of non-IDAT
	chunks.

	Version 1.5.3beta02 [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 clash with the png_jmpbuf macro on some platforms.

	Version 1.5.3beta05 [May 6, 2011]
	Added appropriate feature test macros 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. _ISOC99_SOURCE is
	defined in pngpriv.h to obtain the ISO C99 snprintf definition, when
	available.
	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.
	Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
	optimization configureable.
	IDAT compression failed if preceded by a compressed text chunk (bug
	introduced in libpng-1.5.3beta01-02). This was because the attempt to
	reset the zlib stream in png_write_IDAT happened after the first IDAT
	chunk had been deflated - much too late. In this change internal
	functions were added to claim/release the z_stream and, hopefully, make
	the code more robust. Also deflateEnd checking is added - previously
	libpng would ignore an error at the end of the stream.

	Version 1.5.3beta06 [May 8, 2011]
	Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
	Implemented premultiplied alpha support: png_set_alpha_mode API

	Version 1.5.3beta07 [May 11, 2011]
	Added expand_16 support to the high level interface.
	Added named value and 'flag' gamma support to png_set_gamma. Made a minor
	change from the previous (unreleased) ABI/API to hide the exact value used
	for Macs - it's not a good idea to embed this in the ABI!
	Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
	from pngpriv.h to png.h because they must be visible to applications
	that call png_set_unknown_chunks().
	Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
	before IDAT.

	Version 1.5.3beta08 [May 16, 2011]
	Improved "pngvalid --speed" to exclude more of pngvalid from the time.
	Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
	The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
	parameters are supplied by the caller), while in the absence of cHRM
	sRGB/Rec 709 values are still used.
	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

	Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
	(subscription required; visit
	https://lists.sourceforge.net/lists/listinfo/png-mng-implement
	to subscribe) or to glennrp at users.sourceforge.net

	Glenn R-P