src/png/ANNOUNCE


Libpng 1.5.7 - December 15, 2011

This is a public release of libpng, intended for use in production codes.

Files available for download:

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

   libpng-1.5.7.tar.xz (LZMA-compressed, recommended)
   libpng-1.5.7.tar.gz
   libpng-1.5.7.tar.bz2

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

   lpng157.7z  (LZMA-compressed, recommended)
   lpng157.zip

Other information:

   libpng-1.5.7-README.txt
   libpng-1.5.7-LICENSE.txt

Changes since the last public release (1.5.6):
  Added support for ARM processor (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 concatentation
    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.
  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.
  Added versioning to pnglibconf.h comments.
  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.
  Added run-time detection of NEON support.
  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 compose and rgb to gray (on palette).
  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 desireable 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)
  Removed "zTXt" from warning in generic chunk decompression function.
  Validate time settings passed to pngset() and png_convert_to_rfc1123()
    (Frank Busse).
  Added MINGW support to CMakeLists.txt
  Reject invalid compression flag or method when reading the iTXt chunk.
  Moved pngvalid.c into contrib/libtests
  Rebuilt Makefile.in, configure, etc., with autoconf-2.68
  Replaced an "#if" with "#ifdef" in pngrtran.c
  Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else)
  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.
  Updated CMakeLists.txt to account for the relocation of pngvalid.c
  Minor fixes to pngvalid.c for gcc 4.6.2 compatibility to remove warnings
    reported by earlier versions.

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
Commit	Line	Data
	1
	2	Libpng 1.5.7 - December 15, 2011
	3
	4	This is a public release of libpng, intended for use in production codes.
	5
	6	Files available for download:
	7
	8	Source files with LF line endings (for Unix/Linux) and with a
	9	"configure" script
	10
	11	libpng-1.5.7.tar.xz (LZMA-compressed, recommended)
	12	libpng-1.5.7.tar.gz
	13	libpng-1.5.7.tar.bz2
	14
	15	Source files with CRLF line endings (for Windows), without the
	16	"configure" script
	17
	18	lpng157.7z (LZMA-compressed, recommended)
	19	lpng157.zip
	20
	21	Other information:
	22
	23	libpng-1.5.7-README.txt
	24	libpng-1.5.7-LICENSE.txt
	25
	26	Changes since the last public release (1.5.6):
	27	Added support for ARM processor (Mans Rullgard)
	28	Fixed bug in pngvalid on early allocation failure; fixed type cast in
	29	pngmem.c; pngvalid would attempt to call png_error() if the allocation
	30	of a png_struct or png_info failed. This would probably have led to a
	31	crash. The pngmem.c implementation of png_malloc() included a cast
	32	to png_size_t which would fail on large allocations on 16-bit systems.
	33	Fix for the preprocessor of the Intel C compiler. The preprocessor
	34	splits adjacent @ signs with a space; this changes the concatentation
	35	token from @-@-@ to PNG_JOIN; that should work with all compiler
	36	preprocessors.
	37	Paeth filter speed improvements from work by Siarhei Siamashka. This
	38	changes the 'Paeth' reconstruction function to improve the GCC code
	39	generation on x86. The changes are only part of the suggested ones;
	40	just the changes that definitely improve speed and remain simple.
	41	The changes also slightly increase the clarity of the code.
	42	Check compression_type parameter in png_get_iCCP and remove spurious
	43	casts. The compression_type parameter is always assigned to, so must
	44	be non-NULL. The cast of the profile length potentially truncated the
	45	value unnecessarily on a 16-bit int system, so the cast of the (byte)
	46	compression type to (int) is specified by ANSI-C anyway.
	47	Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left
	48	the sBIT fields in the test pixel as 0, which resulted in a floating
	49	point division by zero which was irrelevant but causes systems where
	50	FP exceptions cause a crash. Added code to pngvalid to turn on FP
	51	exceptions if the appropriate glibc support is there to ensure this is
	52	tested in the future.
	53	Added versioning to pnglibconf.h comments.
	54	Installed more accurate linear to sRGB conversion tables. The slightly
	55	modified tables reduce the number of 16-bit values that
	56	convert to an off-by-one 8-bit value. The "makesRGB.c" code that was used
	57	to generate the tables is now in a contrib/sRGBtables sub-directory.
	58	Added run-time detection of NEON support.
	59	Multiple transform bug fixes plus a work-round for double gamma correction.
	60	libpng does not support more than one transform that requires linear data
	61	at once - if this is tried typically the results is double gamma
	62	correction. Since the simplified APIs can need rgb to gray combined with
	63	a compose operation it is necessary to do one of these outside the main
	64	libpng transform code. This check-in also contains fixes to various bugs
	65	in compose and rgb to gray (on palette).
	66	Fixes for C++ compilation using g++ When libpng source is compiled
	67	using g++. The compiler imposes C++ rules on the C source; thus it
	68	is desireable to make the source work with either C or C++ rules
	69	without throwing away useful error information. This change adds
	70	png_voidcast to allow C semantic (void*) cases or the corresponding
	71	C++ static_cast operation, as appropriate.
	72	Added --noexecstack to assembler file compilation. GCC does not set
	73	this on assembler compilation, even though it does on C compilation.
	74	This creates security issues if assembler code is enabled; the
	75	work-around is to set it by default in the flags for $(CCAS)
	76	Removed "zTXt" from warning in generic chunk decompression function.
	77	Validate time settings passed to pngset() and png_convert_to_rfc1123()
	78	(Frank Busse).
	79	Added MINGW support to CMakeLists.txt
	80	Reject invalid compression flag or method when reading the iTXt chunk.
	81	Moved pngvalid.c into contrib/libtests
	82	Rebuilt Makefile.in, configure, etc., with autoconf-2.68
	83	Replaced an "#if" with "#ifdef" in pngrtran.c
	84	Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else)
	85	Revised pngconf.h to use " __declspec(restrict)" only when MSC_VER >= 1400,
	86	as in libpng-1.5.4.
	87	Put CRLF line endings in the owatcom project files.
	88	Updated CMakeLists.txt to account for the relocation of pngvalid.c
	89	Minor fixes to pngvalid.c for gcc 4.6.2 compatibility to remove warnings
	90	reported by earlier versions.
	91
	92	Send comments/corrections/commendations to png-mng-implement at lists.sf.net
	93	(subscription required; visit
	94	https://lists.sourceforge.net/lists/listinfo/png-mng-implement
	95	to subscribe)
	96	or to glennrp at users.sourceforge.net
	97
	98	Glenn R-P