libpng/ANNOUNCE

Libpng 1.6.0beta04 - December 29, 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

   1.6.0beta04.tar.xz (LZMA-compressed, recommended)
   1.6.0beta04.tar.gz
   1.6.0beta04.tar.bz2

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

   lp160b04.7z  (LZMA-compressed, recommended)
   lp160b04.zip

Other information:

   1.6.0beta04-README.txt
   1.6.0beta04-LICENSE.txt

Changes since the last public release (1.5.7):

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).
  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.
  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.

Version 1.6.0beta04 [December 29, 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.

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