+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 pendantic 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 configureable.
+ IDAT compression failed if preceded by a compressed text chunk (bug
+ introduced in libpng-1.5.3beta01-02). This was because the attempt to
+ reset the zlib stream in png_write_IDAT happened after the first IDAT
+ chunk had been deflated - much too late. In this change internal
+ functions were added to claim/release the z_stream and, hopefully, make
+ the code more robust. Also deflateEnd checking is added - previously
+ libpng would ignore an error at the end of the stream.
+
+Version 1.5.3beta06 [May 8, 2011]
+ Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
+ Implemented premultiplied alpha support: png_set_alpha_mode API
+
+Version 1.5.3beta07 [May 11, 2011]
+ Added expand_16 support to the high level interface.
+ Added named value and 'flag' gamma support to png_set_gamma. Made a minor
+ change from the previous (unreleased) ABI/API to hide the exact value used
+ for Macs - it's not a good idea to embed this in the ABI!
+ Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
+ from pngpriv.h to png.h because they must be visible to applications
+ that call png_set_unknown_chunks().
+ Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
+ before IDAT.
+
+Version 1.5.3beta08 [May 16, 2011]
+ Improved "pngvalid --speed" to exclude more of pngvalid from the time.
+ Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
+ The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
+ parameters are supplied by the caller), while in the absence of cHRM
+ sRGB/Rec 709 values are still used. This introduced a divide-by-zero
+ bug in png_handle_cHRM().
+ The bKGD chunk no longer overwrites the background value set by
+ png_set_background(), allowing the latter to be used before the file
+ header is read. It never performed any useful function to override
+ the default anyway.
+ Added memory overwrite and palette image checks to pngvalid.c
+ Previously palette image code was poorly checked. Since the transformation
+ code has a special palette path in most cases this was a severe weakness.
+ Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
+ expanding an indexed image, always expand to RGBA if transparency is
+ present.
+
+Version 1.5.3beta09 [May 17, 2011]
+ Reversed earlier 1.5.3 change of transformation order; move png_expand_16
+ back where it was. The change doesn't work because it requires 16-bit
+ gamma tables when the code only generates 8-bit ones. This fails
+ silently; the libpng code just doesn't do any gamma correction. Moving
+ the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
+ these are clearly better than none!
+
+Version 1.5.3beta10 [May 20, 2011]
+
+ png_set_background() and png_expand_16() did not work together correctly.
+ This problem is present in 1.5.2; if png_set_background is called with
+ need_expand false and the matching 16 bit color libpng erroneously just
+ treats it as an 8-bit color because of where png_do_expand_16 is in the
+ transform list. This simple fix reduces the supplied colour to 8-bits,
+ so it gets smashed, but this is better than the current behavior.
+ Added tests for expand16, more fixes for palette image tests to pngvalid.
+ Corrects the code for palette image tests and disables attempts to
+ validate palette colors.
+
+Version 1.5.3rc01 [June 3, 2011]
+ No changes.
+
+Version 1.5.3rc02 [June 8, 2011]
+ Fixed uninitialized memory read in png_format_buffer() (Bug report by
+ Frank Busse, CVE-2011-2501, related to CVE-2004-0421).
+
+Version 1.5.3beta11 [June 11, 2011]
+ Fixed png_handle_sCAL which is broken in 1.5. This fixes CVE 2011-2692.
+ Added sCAL to pngtest.png
+ Revised documentation about png_set_user_limits() to say that it also affects
+ png writing.
+ Revised handling of png_set_user_limits() so that it can increase the
+ limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
+ reduce it.
+ Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
+ wrong (high by one) 25% of the time. Dividing by 257 with rounding is
+ wrong in 128 out of 65536 cases. Getting the right answer all the time
+ without division is easy.
+ Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
+ Added projects/owatcom, an IDE project for OpenWatcom to replace
+ scripts/makefile.watcom. This project works with OpenWatcom 1.9. The
+ IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
+ The project is configurable, unlike the Visual Studio project, so long
+ as the developer has an awk.
+ Changed png_set_gAMA to limit the gamma value range so that the inverse
+ of the stored value cannot overflow the fixed point representation,
+ and changed other things OpenWatcom warns about.
+ Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
+ pngvalid to build when ALPHA_MODE is not supported, which is required if
+ it is to build on libpng 1.4.
+ Removed string/memory macros that are no longer used and are not
+ necessarily fully supportable, particularly png_strncpy and png_snprintf.
+ Added log option to pngvalid.c and attempted to improve gamma messages.
+
+Version 1.5.3 [omitted]
+ People found the presence of a beta release following an rc release
+ to be confusing; therefore we bump the version to libpng-1.5.4beta01
+ and there will be no libpng-1.5.3 release.
+
+Version 1.5.4beta01 [June 14, 2011]
+ Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+ to get the same (inaccurate) output as libpng-1.5.2 and earlier.
+ Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
+ outside of an unknown-chunk block in png.h because they are also
+ needed for other uses.
+
+Version 1.5.4beta02 [June 14, 2011]
+ Fixed and clarified LEGACY 16-to-8 scaling code.
+ Added png_set_chop_16() API, to match inaccurate results from previous
+ libpng versions.
+ Removed the ACCURATE and LEGACY options (they are no longer useable)
+ Use the old scaling method for background if png_set_chop_16() was
+ called.
+ Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED
+
+Version 1.5.4beta03 [June 15, 2011]
+ Fixed a problem in png_do_expand_palette() exposed by optimization in
+ 1.5.3beta06
+ Also removed a spurious and confusing "trans" member ("trans") from png_info.
+ The palette expand optimization prevented expansion to an intermediate RGBA
+ form if tRNS was present but alpha was marked to be stripped; this exposed
+ a check for tRNS in png_do_expand_palette() which is inconsistent with the
+ code elsewhere in libpng.
+ Correction to the expand_16 code; removed extra instance of
+ png_set_scale_16_to_8 from pngpriv.h
+
+Version 1.5.4beta04 [June 16, 2011]
+ Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
+ Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
+ Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again. If this is
+ not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
+ Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8
+
+Version 1.5.4beta05 [June 16, 2011]
+ Renamed png_set_strip_16() to png_set_scale_16() and renamed
+ png_set_chop_16() to png_set_strip(16) in an attempt to minimize the
+ behavior changes between libpng14 and libpng15.
+
+Version 1.5.4beta06 [June 18, 2011]
+ Fixed new bug that was causing both strip_16 and scale_16 to be applied.
+
+Version 1.5.4beta07 [June 19, 2011]
+ Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
+ The ACCURATE scale macro is no longer defined in 1.5 - call the
+ png_scale_16_to_8 API. Made sure that PNG_READ_16_TO_8 is still defined
+ if the png_strip_16_to_8 API is present. png_check_fp_number now
+ maintains some state so that positive, negative and zero values are
+ identified. sCAL uses these to be strictly spec conformant.
+
+Version 1.5.4beta08 [June 23, 2011]
+ Fixed pngvalid if ACCURATE_SCALE is defined.
+ Updated scripts/pnglibconf.h.prebuilt.
+
+Version 1.5.4rc01 [June 30, 2011]
+ Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.
+
+Version 1.5.4 [July 7, 2011]
+ No changes.
+
+Version 1.5.5beta01 [July 13, 2011]
+ Fixed some typos and made other minor changes in the manual.
+ Updated contrib/pngminus/makefile.std (Samuli Souminen)
+
+Version 1.5.5beta02 [July 14, 2011]
+ Revised Makefile.am and Makefile.in to look in the right directory for
+ pnglibconf.h.prebuilt
+
+Version 1.5.5beta03 [July 27, 2011]
+ Enabled compilation with g++ compiler. This compiler does not recognize
+ the file extension, so it always compiles with C++ rules. Made minor
+ changes to pngrutil.c to cast results where C++ expects it but C does not.
+ Minor editing of libpng.3 and libpng-manual.txt.
+
+Version 1.5.5beta04 [July 29, 2011]
+ Revised CMakeLists.txt (Clifford Yapp)
+ Updated commentary about the png_rgb_to_gray() default coefficients
+ in the manual and in pngrtran.c
+
+Version 1.5.5beta05 [August 17, 2011]
+ Prevent unexpected API exports from non-libpng DLLs on Windows. The "_DLL"
+ is removed from the test of whether a DLL is being built (this erroneously
+ caused the libpng APIs to be marked as DLL exports in static builds under
+ Microsoft Visual Studio). Almost all of the libpng building configuration
+ is moved from pngconf.h to pngpriv.h, but PNG_DLL_EXPORT remains in
+ pngconf.h, though, so that it is colocated with the import definition (it
+ is no longer used anywhere in the installed headers). The VStudio project
+ definitions have been cleaned up: "_USRDLL" has been removed from the
+ static library builds (this was incorrect), and PNG_USE_DLL has been added
+ to pngvalid to test the functionality (pngtest does not supply it,
+ deliberately). The spurious "_EXPORTS" has been removed from the
+ libpng build (all these errors were a result of copy/paste between project
+ configurations.)
+ Added new types and internal functions for CIE RGB end point handling to
+ pngpriv.h (functions yet to be implemented).
+
+Version 1.5.5beta06 [August 26, 2011]
+ Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set in CMakeLists.txt
+ (Clifford Yap)
+ Fixes to rgb_to_gray and cHRM XYZ APIs (John Bowler):
+ The rgb_to_gray code had errors when combined with gamma correction.
+ Some pixels were treated as true grey when they weren't and such pixels
+ and true grey ones were not gamma corrected (the original value of the
+ red component was used instead). APIs to get and set cHRM using color
+ space end points have been added and the rgb_to_gray code that defaults
+ based on cHRM, and the divide-by-zero bug in png_handle_cHRM (CERT
+ VU#477046, CVE-2011-3328, introduced in 1.5.4) have been corrected.
+ A considerable number of tests has been added to pngvalid for the
+ rgb_to_gray transform.
+ Arithmetic errors in rgb_to_gray whereby the calculated gray value was
+ truncated to the bit depth rather than rounded have been fixed except in
+ the 8-bit non-gamma-corrected case (where consistency seems more important
+ than correctness.) The code still has considerable inaccuracies in the
+ 8-bit case because 8-bit linear arithmetic is used.
+
+Version 1.5.5beta07 [September 7, 2011]
+ Added "$(ARCH)" option to makefile.darwin
+ Added SunOS support to configure.ac and Makefile.am
+ Changed png_chunk_benign_error() to png_warning() in png.c, in
+ png_XYZ_from_xy_checked().
+
+Version 1.5.5beta08 [September 10, 2011]
+ Fixed 64-bit compilation errors (gcc). The errors fixed relate
+ to conditions where types that are 32 bits in the GCC 32-bit
+ world (uLong and png_size_t) become 64 bits in the 64-bit
+ world. This produces potential truncation errors which the
+ compiler correctly flags.
+ Relocated new HAVE_SOLARIS_LD definition in configure.ac
+ Constant changes for 64-bit compatibility (removal of L suffixes). The
+ 16-bit cases still use "L" as we don't have a 16-bit test system.
+
+Version 1.5.5rc01 [September 15, 2011]
+ Removed "L" suffixes in pngpriv.h
+
+Version 1.5.5 [September 22, 2011]
+ No changes.
+
+Version 1.5.6beta01 [September 22, 2011]
+ Fixed some 64-bit type conversion warnings in pngrtran.c
+ Moved row_info from png_struct to a local variable.
+ The various interlace mask arrays have been made into arrays of
+ bytes and made PNG_CONST and static (previously some arrays were
+ marked PNG_CONST and some weren't).
+ Additional checks have been added to the transform code to validate the
+ pixel depths after the transforms on both read and write.
+ Removed some redundant code from pngwrite.c, in png_destroy_write_struct().
+ Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4].
+ This removes the need to allocate temporary strings for chunk names on
+ the stack in the read/write code. Unknown chunk handling still uses the
+ string form because this is exposed in the API.
+
+Version 1.5.6beta02 [September 26, 2011]
+ Added a note in the manual the png_read_update_info() must be called only
+ once with a particular info_ptr.
+ Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro.
+
+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 unitialized 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 (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.
+
+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 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)
+ 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 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.
+ 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.
+