
Libpng 1.2.6rc1 - August 4, 2004

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.

Changes since the last public release (1.2.5):

  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.
  Fixed potential overrun in pngerror.c by using strncpy instead of memcpy.
  Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu.
  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).
  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).
  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.
  #ifdef'ed out some redundancy in png_malloc_default().
  Use png_malloc instead of png_zalloc to allocate the pallete.
  Rearranged order of processing of color types in png_handle_tRNS().
  Added PNG_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 and
    PNG_SET_USER_LIMITS_SUPPORTED macro to override them..
  Fixed wrong cast of returns from png_get_user_width|height_max().
  Fixed buffer overflow vulnerability in png_handle_tRNS()
  Fixed integer arithmetic overflow vulnerability in png_read_png().
  Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
    duplicate chunk types to go undetected.

Send comments/corrections/commendations to
png-implement@ccrc.wustl.edu or to glennrp@users.sourceforge.net

Glenn R-P