+Libpng 1.5.6 - November 3, 2011
-Libpng 1.2.6 - August 15, 2004
+This is a public release of libpng, intended for use in production codes.
-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:
-Changes since the last public release (1.2.5):
+Source files with LF line endings (for Unix/Linux) and with a
+"configure" script
- 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.
- 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.
- Changed some "keep the compiler happy" from empty statements to returns,
-Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution
- Revised makefile.darwin and makefile.solaris. Removed makefile.macosx.
- Revised pngtest's png_debug_malloc() to use png_malloc() instead of
- png_malloc_default() which is not supposed to be exported.
- Fixed old bug in RGB to Gray transformation.
- Fixed problem with 64-bit compilers by casting arguments to abs()
- to png_int_32.
- Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9).
- Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin)
- Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles.
- Added code to update the row_info->colortype in png_do_read_filler() (MSB).
- Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid
- trouble with some 64-bit compilers. Created PNG_OUT_OF_RANGE() macro.
- Revised documentation of png_set_keep_unknown_chunks().
- Check handle_as_unknown status in pngpread.c, as in pngread.c previously.
- Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h
- Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c
- Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
+ libpng-1.5.6.tar.xz (LZMA-compressed, recommended)
+ libpng-1.5.6.tar.gz
+ libpng-1.5.6.tar.bz2
-Send comments/corrections/commendations to
-png-implement@ccrc.wustl.edu or to glennrp@users.sourceforge.net
+Source files with CRLF line endings (for Windows), without the
+"configure" script
+
+ lpng156.7z (LZMA-compressed, recommended)
+ lpng156.zip
+
+Other information:
+
+ libpng-1.5.6-README.txt
+ libpng-1.5.6-LICENSE.txt
+
+Changes since the last public release (1.5.5):
+
+ 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_desgtroy_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.
+ Added a note in the manual the png_read_update_info() must be called only
+ once with a particular info_ptr.
+ 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.
+ Fixed typo in Makefile.in and Makefile.am ("-M Wl" should be "-M -Wl")."
+ 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.
+ 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.
+ Made png_ptr->prev_row an aligned pointer into png_ptr->big_prev_row
+ (Mans Rullgard).
+ Changed misleading "Missing PLTE before cHRM" warning to "Out of place cHRM"
+ Added PNG_LSR() and PNG_LSL() macros to defend against buggy compilers that
+ evaluate non-taken code branches and complain about out-of-range shifts.
+ Renamed the local variable 'byte' because it appears in a MSYS header
+ file.
+ Added #define PNG_ALIGN_TYPE PNG_ALIGN_NONE to contrib/pngminim/*/pngusr.h
+
+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