Release libpng version 1.6.36

The new libpng license comprises the terms and conditions from the zlib
license, and the disclaimer from the Boost license.

The legacy libpng license, used until libpng-1.6.35, is appended to the
new license, following the precedent established in the Python Software
Foundation License version 2.

From now on, the list of contributing authors shall be maintained in a
separate AUTHORS file.

The lists of previous contributing authors, mentioned in the legacy
libpng license and considered to be an integral part of that license,
are kept intact, with no further updates.

ANNOUNCE

@@ -1,64 +1,77 @@
-Libpng 1.6.26 - October 20, 2016
+libpng 1.6.36 - December 1, 2018
+================================
 
-This is a public release of libpng, intended for use in production codes.
+This is a public release of libpng, intended for use in production code.
 
-Files available for download:
 
-Source files with LF line endings (for Unix/Linux) and with a
-"configure" script
+Files available for download
+----------------------------
 
-   libpng-1.6.26.tar.xz (LZMA-compressed, recommended)
-   libpng-1.6.26.tar.gz
+Source files with LF line endings (for Unix/Linux):
 
-Source files with CRLF line endings (for Windows), without the
-"configure" script
+ * libpng-1.6.36.tar.xz (LZMA-compressed, recommended)
+ * libpng-1.6.36.tar.gz
 
-   lpng1626.7z  (LZMA-compressed, recommended)
-   lpng1626.zip
+Source files with CRLF line endings (for Windows):
+
+ * lp1636.7z (LZMA-compressed, recommended)
+ * lp1636.zip
 
 Other information:
 
-   libpng-1.6.26-README.txt
-   libpng-1.6.26-LICENSE.txt
-   libpng-1.6.26-*.asc (armored detached GPG signatures)
+ * README.md
+ * LICENSE.md
+ * AUTHORS.md
+ * TRADEMARK.md
 
-Changes since the last public release (1.6.25):
 
-  Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
-    bugfix by John Bowler).
-  Do not issue a png_error() on read in png_set_pCAL() because png_handle_pCAL
-    has allocated memory that libpng needs to free.
-  Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c
-  Issue a png_benign_error instead of a png_error on ADLER32 mismatch
-    while decoding compressed data chunks.
-  Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngpriv.h, pngstruct.h, and
-    pngrutil.c.
-  If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
-    ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
-  Issue png_benign_error() on ADLER32 checksum mismatch instead of png_error().
-  Add tests/badcrc.png and tests/badadler.png to tests/pngtest.
-  Merged pngtest.c with libpng-1.7.0beta84/pngtest.c
-  Updated the documentation about CRC and ADLER32 handling.
-  Quieted 117 warnings from clang-3.8 in pngtrans.c, pngread.c,
-     pngwrite.c, pngunknown.c, and pngvalid.c.
-  Quieted the 144 remaining -Wconversion compiler warnings by
-    revising the png_isaligned() macro and trivial changes in png.c,
-    pngerror.c, pngget.c, pngmem.c, pngset.c, pngrtran.c, pngrutil.c,
-    pngwtran.c, pngwrite.c, and pngwutil.c.
-  Quieted (bogus?) clang warnings about "absolute value has no effect"
-    when PNG_USE_ABS is defined.
-  Fixed offsets in contrib/intel/intel_sse.patch
-  Changed integer constant 4294967294 to unsigned 4294967294U in pngconf.h
-    to avoid a signed/unsigned compare in the preprocessor.
-  Use zlib-1.2.8.1 inflateValidate() instead of inflateReset2() to
-    optionally avoid ADLER32 evaluation.
-  Cosmetic change, "ptr != 0" to "ptr != NULL" in png.c and pngrutil.c
-  Despammed email addresses (replaced "@" with " at ").
+IMPORTANT licensing update: libpng license v2
+---------------------------------------------
 
-Send comments/corrections/commendations to png-mng-implement at lists.sf.net
-(subscription required; visit
+The new libpng license comprises the terms and conditions from the zlib
+license, and the disclaimer from the Boost license.
+
+The legacy libpng license, used until libpng-1.6.35, is appended to the
+new license, following the precedent established in the Python Software
+Foundation License version 2.
+
+From now on, the list of contributing authors shall be maintained in a
+separate AUTHORS file.  The lists of previous contributing authors,
+mentioned in the legacy libpng license and considered to be an integral
+part of that license, are kept intact, with no further updates.
+
+
+Changes since the previous public release (version 1.6.35)
+----------------------------------------------------------
+
+ * Optimized png_do_expand_palette for ARM processors.
+   Improved performance by around 10-22% on a recent ARM Chromebook.
+   (Contributed by Richard Townsend, ARM Holdings)
+ * Fixed manipulation of machine-specific optimization options.
+   (Contributed by Vicki Pfau)
+ * Used memcpy instead of manual pointer arithmetic on Intel SSE2.
+   (Contributed by Samuel Williams)
+ * Fixed build errors with MSVC on ARM64.
+   (Contributed by Zhijie Liang)
+ * Fixed detection of libm in CMakeLists.
+   (Contributed by Cameron Cawley)
+ * Fixed incorrect creation of pkg-config file in CMakeLists.
+   (Contributed by Kyle Bentley)
+ * Fixed the CMake build on Windows MSYS by avoiding symlinks.
+ * Fixed a build warning on OpenBSD.
+   (Contributed by Theo Buehler)
+ * Fixed various typos in comments.
+   (Contributed by "luz.paz")
+ * Raised the minimum required CMake version from 3.0.2 to 3.1.
+ * Removed yet more of the vestigial support for pre-ANSI C compilers.
+ * Removed ancient makefiles for ancient systems that have been broken
+   across all previous libpng-1.6.x versions.
+ * Removed the Y2K compliance statement and the export control
+   information.
+ * Applied various code style and documentation fixes.
+
+
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net.
+Subscription is required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
-to subscribe)
-or to glennrp at users.sourceforge.net
-
-Glenn R-P
+to subscribe.

AUTHORS

@@ -0,0 +1,45 @@
+PNG REFERENCE LIBRARY AUTHORS
+=============================
+
+This is the list of PNG Reference Library ("libpng") Contributing
+Authors, for copyright and licensing purposes.
+
+ * Andreas Dilger
+ * Cosmin Truta
+ * Dave Martindale
+ * Eric S. Raymond
+ * Gilles Vollant
+ * Glenn Randers-Pehrson
+ * Greg Roelofs
+ * Guy Eric Schalnat
+ * James Yu
+ * John Bowler
+ * Kevin Bracey
+ * Magnus Holmgren
+ * Mandar Sahastrabuddhe
+ * Mans Rullgard
+ * Matt Sarett
+ * Mike Klein
+ * Paul Schmidt
+ * Sam Bushell
+ * Samuel Williams
+ * Simon-Pierre Cadieux
+ * Tim Wegner
+ * Tom Lane
+ * Tom Tanner
+ * Vadim Barkov
+ * Willem van Schaik
+ * Zhijie Liang
+ * Arm Holdings
+   - Richard Townsend
+ * Google Inc.
+   - Matt Sarett
+   - Mike Klein
+
+The build projects, the build scripts, the test scripts, and other
+files in the "projects", "scripts" and "tests" directories, have other
+copyright owners, but are released under the libpng license.
+
+Some files in the "contrib" directory, and some tools-generated files
+that are distributed with libpng, have other copyright owners, and are
+released under other open source licenses.

CHANGES

@@ -1,4 +1,3 @@
-#if 0
 CHANGES - changes for libpng
 
 version 0.1 [March 29, 1995]
@@ -833,7 +832,7 @@ Version 1.0.7beta11 [May 7, 2000]
   Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
     which are no longer used.
   Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
-    defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXT_SUPPORTED
+    defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXt_SUPPORTED
     is defined.
   Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
     overrun when old applications fill the info_ptr->text structure directly.
@@ -1454,7 +1453,7 @@ Version 1.2.6beta4 [July 28, 2004]
     sequential read support.
   Added some "#if PNG_WRITE_SUPPORTED" blocks.
   Added #ifdef to remove some redundancy in png_malloc_default().
-  Use png_malloc instead of png_zalloc to allocate the pallete.
+  Use png_malloc instead of png_zalloc to allocate the palette.
 
 Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
   Fixed buffer overflow vulnerability (CVE-2004-0597) in png_handle_tRNS().
@@ -3259,7 +3258,7 @@ Version 1.5.2beta01 [February 13, 2011]
   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.
+  Fixed gcc pedantic warnings.
   Handle longjmp in Cygwin.
   Fixed png_get_current_row_number() in the interlaced case.
   Cleaned up ALPHA flags and transformations.
@@ -3359,7 +3358,7 @@ Version 1.5.3beta05 [May 6, 2011]
   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.
+    optimization configurable.
   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
@@ -3643,7 +3642,7 @@ Version 1.5.6beta05 [October 12, 2011]
   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.
+  Removed two redundant tests for uninitialized 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.
@@ -3689,7 +3688,7 @@ Version 1.5.7beta01 [November 4, 2011]
     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
+    splits adjacent @ signs with a space; this changes the concatenation
     token from @-@-@ to PNG_JOIN; that should work with all compiler
     preprocessors.
   Paeth filter speed improvements from work by Siarhei Siamashka. This
@@ -3735,7 +3734,7 @@ Version 1.5.7beta03 [November 17, 2011]
     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
+    is desirable 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.
@@ -4061,7 +4060,7 @@ Version 1.6.0beta17 [March 10, 2012]
     possible to call png_inflate() incrementally.  A warning is no longer
     issued if the language tag or translated keyword in the iTXt chunk
     has zero length.
-  If benign errors are disabled use maximum window on ancilliary inflate.
+  If benign errors are disabled use maximum window on ancillary inflate.
     This works round a bug introduced in 1.5.4 where compressed ancillary
     chunks could end up with a too-small windowBits value in the deflate
     header.
@@ -4176,7 +4175,7 @@ Version 1.6.0beta27 [August 11, 2012]
     declared even though the functions are never actually defined.  This
     change provides a dummy definition so that the declarations work, yet any
     implementation will fail to compile because of an incomplete type.
-  Re-eliminated the use of strcpy() in pngtest.c.  An unncessary use of
+  Re-eliminated the use of strcpy() in pngtest.c.  An unnecessary use of
     strcpy() was accidentally re-introduced in libpng16; this change replaces
     it with strncpy().
   Eliminated use of png_sizeof(); use sizeof() instead.
@@ -4309,7 +4308,7 @@ Version 1.6.0beta31 [November 1, 2012]
     resulting in VS2010 having to update the files.
   Removed non-working ICC profile support code that was mostly added to
     libpng-1.6.0beta29 and beta30. There was too much code for too little
-    gain; implementing full ICC color correction may be desireable but is left
+    gain; implementing full ICC color correction may be desirable but is left
     up to applications.
 
 Version 1.6.0beta32 [November 25, 2012]
@@ -4592,7 +4591,7 @@ Version 1.6.3beta07 [June 8, 2013]
     the optimizations ('check' vs 'api') are exposed in the public header files
     except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
     decision about whether or not to use the optimizations.
-  Protect symbol prefixing against CC/CPPFLAGS/CFLAGS useage.
+  Protect symbol prefixing against CC/CPPFLAGS/CFLAGS usage.
     Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
     on __ARM_NEON__ from configure time to compile time.  This breaks symbol
     prefixing because the definition of the special png_init_filter_functions
@@ -5635,7 +5634,7 @@ Version 1.6.24beta02 [June 23, 2016]
     to All and adds a list of the warnings that need to be turned off.  This is
     semi-documentary; the intent is to tell libpng users which warnings have
     been examined and judged non-fixable at present.  The warning about
-    structure padding is fixable, but it would be a signficant change (moving
+    structure padding is fixable, but it would be a significant change (moving
     structure members around).
 
 Version 1.6.24beta03 [July 4, 2016]
@@ -5754,11 +5753,344 @@ Version 1.6.26 [October 20, 2016]
   Cosmetic change, "ptr != 0" to "ptr != NULL" in png.c and pngrutil.c
   Despammed email addresses (replaced "@" with " at ").
 
+Version 1.6.27beta01 [November 2, 2016]
+  Restrict the new ADLER32-skipping to IDAT chunks.  It broke iCCP chunk
+    handling: an erroneous iCCP chunk would throw a png_error and reject the
+    entire PNG image instead of rejecting just the iCCP chunk with a warning,
+    if built with zlib-1.2.8.1.
+
+Version 1.6.27rc01 [December 27, 2016]
+  Control ADLER32 checking with new PNG_IGNORE_ADLER32 option. Fixes
+    an endless loop when handling erroneous ADLER32 checksums; bug
+    introduced in libpng-1.6.26.
+  Removed the use of a macro containing the pre-processor 'defined'
+    operator.  It is unclear whether this is valid; a macro that
+    "generates" 'defined' is not permitted, but the use of the word
+    "generates" within the C90 standard seems to imply more than simple
+    substitution of an expression itself containing a well-formed defined
+    operation.
+  Added ARM support to CMakeLists.txt (Andreas Franek).
+
+Version 1.6.27 [December 29, 2016]
+  Fixed a potential null pointer dereference in png_set_text_2() (bug report
+    and patch by Patrick Keshishian, CVE-2016-10087).
+
+Version 1.6.28rc01 [January 3, 2017]
+  Fixed arm/aarch64 detection in CMakeLists.txt (Gianfranco Costamagna).
+  Added option to Cmake build allowing a custom location of zlib to be
+    specified in a scenario where libpng is being built as a subproject
+    alongside zlib by another project (Sam Serrels).
+  Changed png_ptr->options from a png_byte to png_uint_32, to accommodate
+    up to 16 options.
+
+Version 1.6.28rc02 [January 4, 2017]
+  Added "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
+  Moved SSE2 optimization code into the main libpng source directory.
+    Configure libpng with "configure --enable-intel-sse" or compile
+    libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
+
+Version 1.6.28rc03 [January 4, 2017]
+  Backed out the SSE optimization and last CMakeLists.txt to allow time for QA.
+
+Version 1.6.28 [January 5, 2017]
+  No changes.
+
+Version 1.6.29beta01 [January 12, 2017]
+  Readded "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
+  Moved SSE2 optimization code into the main libpng source directory.
+    Configure libpng with "configure --enable-intel-sse" or compile
+    libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
+  Simplified conditional compilation in pngvalid.c, for AIX (Michael Felt).
+
+Version 1.6.29beta02 [February 22, 2017]
+  Avoid conditional directives that break statements in pngrutil.c (Romero
+    Malaquias)
+  The contrib/examples/pngtopng.c recovery code was in the wrong "if"
+    branches; the comments were correct.
+  Added code for PowerPC VSX optimisation (Vadim Barkov).
+
+Version 1.6.29beta03 [March 1, 2017]
+  Avoid potential overflow of shift operations in png_do_expand() (Aaron Boxer).
+  Change test ZLIB_VERNUM >= 0x1281 to ZLIB_VERNUM >= 0x1290 in pngrutil.c
+    because Solaris 11 distributes zlib-1.2.8.f that is older than 1.2.8.1,
+    as suggested in zlib FAQ, item 24.
+  Suppress clang warnings about implicit sign changes in png.c
+
+Version 1.6.29 [March 16, 2017]
+  No changes.
+
+Version 1.6.30beta01 [April 1, 2017]
+  Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in
+    makefile.linux and makefile.solaris-x86 (Cosmin).
+  Revised documentation of png_get_error_ptr() in the libpng manual.
+  Silence clang -Wcomma and const drop warnings (Viktor Szakats).
+  Update Sourceforge URLs in documentation (https instead of http).
+
+Version 1.6.30beta02 [April 22, 2017]
+  Document need to check for integer overflow when allocating a pixel
+    buffer for multiple rows in contrib/gregbook, contrib/pngminus,
+    example.c, and in the manual (suggested by Jaeseung Choi). This
+    is similar to the bug reported against pngquant in CVE-2016-5735.
+  Removed reference to the obsolete PNG_SAFE_LIMITS macro in the documentation.
+
+Version 1.6.30beta03 [May 22, 2017]
+  Check for integer overflow in contrib/visupng and contrib/tools/genpng.
+  Do not double evaluate CMAKE_SYSTEM_PROCESSOR in CMakeLists.txt.
+  Test CMAKE_HOST_WIN32 instead of WIN32 in CMakeLists.txt.
+  Fix some URL in documentation.
+
+Version 1.6.30beta04 [June 7, 2017]
+  Avoid writing an empty IDAT when the last IDAT exactly fills the
+    compression buffer (bug report by Brian Baird). This bug was
+    introduced in libpng-1.6.0.
+
+Version 1.6.30rc01 [June 14, 2017]
+  No changes.
+
+Version 1.6.30rc02 [June 25, 2017]
+  Update copyright year in pnglibconf.h, make ltmain.sh executable.
+  Add a reference to the libpng.download site in README.
+
+Version 1.6.30 [June 28, 2017]
+  No changes.
+
+Version 1.6.31beta01 [July 5, 2017]
+  Guard the definition of _POSIX_SOURCE in pngpriv.h (AIX already defines it;
+    bug report by Michael Felt).
+  Revised pngpriv.h to work around failure to compile arm/filter_neon.S
+    ("typedef" directive is unrecognized by the assembler). The problem
+    was introduced in libpng-1.6.30beta01.
+  Added "Requires: zlib" to libpng.pc.in (Pieter Neerincx).
+  Added special case for FreeBSD in arm/filter_neon.S (Maya Rashish).
+
+Version 1.6.31beta02 [July 8, 2017]
+  Added instructions for disabling hardware optimizations in INSTALL.
+  Added "--enable-hardware-optimizations" configuration flag to enable
+    or disable all hardware optimizations with one flag.
+
+Version 1.6.31beta03 [July 9, 2017]
+  Updated CMakeLists.txt to add INTEL_SSE and MIPS_MSA platforms.
+  Changed "int" to "png_size_t" in intel/filter_sse2.c to prevent
+    possible integer overflow (Bug report by John Bowler).
+  Quieted "declaration after statement" warnings in intel/filter_sse2.c.
+  Added scripts/makefile-linux-opt, which has hardware optimizations enabled.
+
+Version 1.6.31beta04 [July 11, 2017]
+  Removed one of the GCC-7.1.0 'strict-overflow' warnings that result when
+    integers appear on both sides of a compare.  Worked around the others by
+    forcing the strict-overflow setting in the relevant functions to a level
+    where they are not reported (John Bowler).
+  Changed "FALL THROUGH" comments to "FALLTHROUGH" because GCC doesn't like
+    the space.
+  Worked around some C-style casts from (void*) because g++ 5.4.0 objects
+    to them.
+  Increased the buffer size for 'sprint' to pass the gcc 7.1.0 'sprint
+    overflow' check that is on by default with -Wall -Wextra.
+
+Version 1.6.31beta05 [July 13, 2017]
+  Added eXIf chunk support.
+
+Version 1.6.31beta06 [July 17, 2017]
+  Added a minimal eXIf chunk (with Orientation and FocalLengthIn35mmFilm
+    tags) to pngtest.png.
+
+Version 1.6.31beta07 [July 18, 2017]
+  Revised the eXIf chunk in pngtest.png to fix "Bad IFD1 Directory" warning.
+
+Version 1.6.31rc01 [July 19, 2017]
+  No changes.
+
+Version 1.6.31rc02 [July 25, 2017]
+  Fixed typo in example.c (png_free_image should be png_image_free) (Bug
+    report by John Smith)
+
+Version 1.6.31 [July 27, 2017]
+  No changes.
+
+Version 1.6.32beta01 [July 31, 2017]
+  Avoid possible NULL dereference in png_handle_eXIf when benign_errors
+    are allowed. Avoid leaking the input buffer "eXIf_buf".
+  Eliminated png_ptr->num_exif member from pngstruct.h and added num_exif
+    to arguments for png_get_eXIf() and png_set_eXIf().
+  Added calls to png_handle_eXIf(() in pngread.c and png_write_eXIf() in
+    pngwrite.c, and made various other fixes to png_write_eXIf().
+  Changed name of png_get_eXIF and png_set_eXIf() to png_get_eXIf_1() and
+    png_set_eXIf_1(), respectively, to avoid breaking API compatibility
+    with libpng-1.6.31.
+
+Version 1.6.32beta02 [August 1, 2017]
+  Updated contrib/libtests/pngunknown.c with eXIf chunk.
+
+Version 1.6.32beta03 [August 2, 2017]
+  Initialized btoa[] in pngstest.c
+  Stop memory leak when returning from png_handle_eXIf() with an error
+    (Bug report from the OSS-fuzz project).
+
+Version 1.6.32beta04 [August 2, 2017]
+  Replaced local eXIf_buf with info_ptr-eXIf_buf in png_handle_eXIf().
+  Update libpng.3 and libpng-manual.txt about eXIf functions.
+
+Version 1.6.32beta05 [August 2, 2017]
+  Restored png_get_eXIf() and png_set_eXIf() to maintain API compatibility.
+
+Version 1.6.32beta06 [August 2, 2017]
+  Removed png_get_eXIf_1() and png_set_eXIf_1().
+
+Version 1.6.32beta07 [August 3, 2017]
+  Check length of all chunks except IDAT against user limit to fix an
+    OSS-fuzz issue (Fixes CVE-2017-12652).
+
+Version 1.6.32beta08 [August 3, 2017]
+  Check length of IDAT against maximum possible IDAT size, accounting
+    for height, rowbytes, interlacing and zlib/deflate overhead.
+  Restored png_get_eXIf_1() and png_set_eXIf_1(), because strlen(eXIf_buf)
+    does not work (the eXIf chunk data can contain zeroes).
+
+Version 1.6.32beta09 [August 3, 2017]
+  Require cmake-2.8.8 in CMakeLists.txt. Revised symlink creation,
+    no longer using deprecated cmake LOCATION feature (Clifford Yapp).
+  Fixed five-byte error in the calculation of IDAT maximum possible size.
+  
+Version 1.6.32beta10 [August 5, 2017]
+  Moved chunk-length check into a png_check_chunk_length() private
+    function (Suggested by Max Stepin).
+  Moved bad pngs from tests to contrib/libtests/crashers
+  Moved testing of bad pngs into a separate tests/pngtest-badpngs script
+  Added the --xfail (expected FAIL) option to pngtest.c. It writes XFAIL
+    in the output but PASS for the libpng test.
+  Require cmake-3.0.2 in CMakeLists.txt (Clifford Yapp).
+  Fix "const" declaration info_ptr argument to png_get_eXIf_1() and the
+    num_exif argument to png_get_eXIf_1() (Github Issue 171).
+
+Version 1.6.32beta11 [August 7, 2017]
+  Added "eXIf" to "chunks_to_ignore[]" in png_set_keep_unknown_chunks().
+  Added huge_IDAT.png and empty_ancillary_chunks.png to testpngs/crashers.
+  Make pngtest --strict, --relax, --xfail options imply -m (multiple).
+  Removed unused chunk_name parameter from png_check_chunk_length().
+  Relocated setting free_me for eXIf data, to stop an OSS-fuzz leak.
+  Initialize profile_header[] in png_handle_iCCP() to fix OSS-fuzz issue.
+  Initialize png_ptr->row_buf[0] to 255 in png_read_row() to fix OSS-fuzz UMR.
+  Attempt to fix a UMR in png_set_text_2() to fix OSS-fuzz issue.
+  Increase minimum zlib stream from 9 to 14 in png_handle_iCCP(), to account
+    for the minimum 'deflate' stream, and relocate the test to a point
+    after the keyword has been read.
+  Check that the eXIf chunk has at least 2 bytes and begins with "II" or "MM".
+
+Version 1.6.32rc01 [August 18, 2017]
+  Added a set of "huge_xxxx_chunk.png" files to contrib/testpngs/crashers,
+    one for each known chunk type, with length = 2GB-1.
+  Check for 0 return from png_get_rowbytes() and added some (size_t) typecasts
+    in contrib/pngminus/*.c to stop some Coverity issues (162705, 162706,
+    and 162707).
+  Renamed chunks in contrib/testpngs/crashers to avoid having files whose
+    names differ only in case; this causes problems with some platforms
+    (github issue #172).
+
+Version 1.6.32rc02 [August 22, 2017]
+  Added contrib/oss-fuzz directory which contains files used by the oss-fuzz
+    project (https://github.com/google/oss-fuzz/tree/master/projects/libpng).
+
+Version 1.6.32 [August 24, 2017]
+  No changes.
+
+Version 1.6.33beta01 [August 28, 2017]
+  Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing
+    parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).
+  Fixed off-by-one error in png_do_check_palette_indexes() (Bug report
+    by Mick P., Source Forge Issue #269).
+
+Version 1.6.33beta02 [September 3, 2017]
+  Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
+    to fix shortlived oss-fuzz issue 3234.
+  Compute a larger limit on IDAT because some applications write a deflate
+    buffer for each row (Bug report by Andrew Church).
+  Use current date (DATE) instead of release-date (RDATE) in last
+    changed date of contrib/oss-fuzz files.
+  Enabled ARM support in CMakeLists.txt (Bernd Kuhls).
+
+Version 1.6.33beta03 [September 14, 2017]
+  Fixed incorrect typecast of some arguments to png_malloc() and
+    png_calloc() that were png_uint_32 instead of png_alloc_size_t
+    (Bug report by "irwir" in Github libpng issue #175).
+  Use pnglibconf.h.prebuilt when building for ANDROID with cmake (Github
+    issue 162, by rcdailey).
+
+Version 1.6.33rc01 [September 20, 2017]
+  Initialize memory allocated by png_inflate to zero, using memset, to
+    stop an oss-fuzz "use of uninitialized value" detection in png_set_text_2()
+    due to truncated iTXt or zTXt chunk.
+  Initialize memory allocated by png_read_buffer to zero, using memset, to
+    stop an oss-fuzz "use of uninitialized value" detection in
+    png_icc_check_tag_table() due to truncated iCCP chunk.
+  Removed a redundant test (suggested by "irwir" in Github issue #180).
+
+Version 1.6.33rc02 [September 23, 2017]
+  Added an interlaced version of each file in contrib/pngsuite.
+  Relocate new memset() call in pngrutil.c.
+  Removed more redundant tests (suggested by "irwir" in Github issue #180).
+  Add support for loading images with associated alpha in the Simplified
+    API (Samuel Williams).
+
+Version 1.6.33 [September 28, 2017]
+  Revert contrib/oss-fuzz/libpng_read_fuzzer.cc to libpng-1.6.32 state.
+  Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
+  Add end_info structure and png_read_end() to the libpng fuzzer.
+
+Version 1.6.34 [September 29, 2017]
+  Removed contrib/pngsuite/i*.png; some of them caused test failures.
+
+Version 1.6.35beta01 [March 6, 2018]
+  Restored 21 of the contrib/pngsuite/i*.png, which do not cause test
+    failures. Placed the remainder in contrib/pngsuite/interlaced/i*.png.
+  Added calls to png_set_*() transforms commonly used by browsers to
+    the fuzzer.
+  Removed some unnecessary brackets in pngrtran.c
+  Fixed miscellaneous typos (Patch by github user "luzpaz").
+  Change "ASM C" to "C ASM" in CMakeLists.txt
+  Fixed incorrect handling of bKGD chunk in sub-8-bit files (Cosmin)
+  Added hardware optimization directories to zip and 7z distributions.
+  Fixed incorrect bitmask for options.
+  Fixed many spelling typos.
+
+Version 1.6.35beta02 [March 28, 2018]
+  Make png_get_iCCP consistent with man page (allow compression-type argument
+  to be NULL, bug report by Lenard Szolnoki).
+
+Version 1.6.35 [July 15, 2018]
+  Replaced the remaining uses of png_size_t with size_t (Cosmin)
+  Fixed the calculation of row_factor in png_check_chunk_length
+    (reported by Thuan Pham in SourceForge issue #278)
+  Added missing parentheses to a macro definition
+    (suggested by "irwir" in GitHub issue #216)
+
+Version 1.6.36 [December 1, 2018]
+  Optimized png_do_expand_palette for ARM processors.
+  Improved performance by around 10-22% on a recent ARM Chromebook.
+  (Contributed by Richard Townsend, ARM Holdings)
+  Fixed manipulation of machine-specific optimization options.
+  (Contributed by Vicki Pfau)
+  Used memcpy instead of manual pointer arithmetic on Intel SSE2.
+  (Contributed by Samuel Williams)
+  Fixed build errors with MSVC on ARM64.
+  (Contributed by Zhijie Liang)
+  Fixed detection of libm in CMakeLists.
+  (Contributed by Cameron Cawley)
+  Fixed incorrect creation of pkg-config file in CMakeLists.
+  (Contributed by Kyle Bentley)
+  Fixed the CMake build on Windows MSYS by avoiding symlinks.
+  Fixed a build warning on OpenBSD.
+  (Contributed by Theo Buehler)
+  Fixed various typos in comments.
+  (Contributed by "luz.paz")
+  Raised the minimum required CMake version from 3.0.2 to 3.1.
+  Removed yet more of the vestigial support for pre-ANSI C compilers.
+  Removed ancient makefiles for ancient systems that have been broken
+  across all previous libpng-1.6.x versions.
+  Removed the Y2K compliance statement and the export control
+  information.
+  Applied various code style and documentation fixes.
+
 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
-#endif
+to subscribe).

CMakeLists.txt

@@ -1,58 +1,52 @@
 # CMakeLists.txt
 
-# Copyright (C) 2007,2009-2016 Glenn Randers-Pehrson
+# Copyright (C) 2018 Cosmin Truta
+# Copyright (C) 2007,2009-2018 Glenn Randers-Pehrson
 # Written by Christian Ehrlicher, 2007
 # Revised by Roger Lowman, 2009-2010
-# Revised by Clifford Yapp, 2011-2012
+# Revised by Clifford Yapp, 2011-2012,2017
 # Revised by Roger Leigh, 2016
+# Revised by Andreas Franek, 2016
+# Revised by Sam Serrels, 2017
+# Revised by Vadim Barkov, 2017
+# Revised by Vicky Pfau, 2018
+# Revised by Cameron Cawley, 2018
+# Revised by Cosmin Truta, 2018
+# Revised by Kyle Bentley, 2018
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
 # and license in png.h
 
-cmake_minimum_required(VERSION 2.8.3)
-cmake_policy(VERSION 2.8.3)
+cmake_minimum_required(VERSION 3.1)
+cmake_policy(VERSION 3.1)
 
-# Set MacOSX @rpath usage globally.
-if (POLICY CMP0020)
-  cmake_policy(SET CMP0020 NEW)
-endif(POLICY CMP0020)
-if (POLICY CMP0042)
-  cmake_policy(SET CMP0042 NEW)
-endif(POLICY CMP0042)
-# Use new variable expansion policy.
-if (POLICY CMP0053)
-  cmake_policy(SET CMP0053 NEW)
-endif(POLICY CMP0053)
-if (POLICY CMP0054)
-  cmake_policy(SET CMP0054 NEW)
-endif(POLICY CMP0054)
-
-set(CMAKE_CONFIGURATION_TYPES "Release;Debug;MinSizeRel;RelWithDebInfo")
-
-project(libpng C)
+project(libpng C ASM)
 enable_testing()
 
 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 6)
-set(PNGLIB_RELEASE 26)
+set(PNGLIB_RELEASE 36)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
-# needed packages
-find_package(ZLIB REQUIRED)
-include_directories(${ZLIB_INCLUDE_DIR})
+include(GNUInstallDirs)
 
-if(NOT WIN32)
-  find_library(M_LIBRARY
-    NAMES m
-    PATHS /usr/lib /usr/local/lib
-  )
-  if(NOT M_LIBRARY)
-    message(STATUS "math lib 'libm' not found; floating point support disabled")
-  endif()
+# needed packages
+
+# Allow users to specify location of Zlib.
+# Useful if zlib is being built alongside this as a sub-project.
+option(PNG_BUILD_ZLIB "Custom zlib Location, else find_package is used" OFF)
+
+if(NOT PNG_BUILD_ZLIB)
+  find_package(ZLIB REQUIRED)
+  include_directories(${ZLIB_INCLUDE_DIR})
+endif()
+
+if(UNIX AND NOT APPLE AND NOT BEOS AND NOT HAIKU)
+  find_library(M_LIBRARY m)
 else()
-  # not needed on windows
+  # libm is not needed and/or not available
   set(M_LIBRARY "")
 endif()
 
@@ -63,12 +57,145 @@ option(PNG_TESTS  "Build libpng tests" ON)
 
 # Many more configuration options could be added here
 option(PNG_FRAMEWORK "Build OS X framework" OFF)
-option(PNG_DEBUG     "Build with debug output" OFF)
-option(PNGARG        "Disable ANSI-C prototypes" OFF)
+option(PNG_DEBUG "Build with debug output" OFF)
+option(PNG_HARDWARE_OPTIMIZATIONS "Enable hardware optimizations" ON)
 
 set(PNG_PREFIX "" CACHE STRING "Prefix to add to the API function names")
 set(DFA_XTRA "" CACHE FILEPATH "File containing extra configuration settings")
 
+if(PNG_HARDWARE_OPTIMIZATIONS)
+
+# set definitions and sources for arm
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm" OR
+  CMAKE_SYSTEM_PROCESSOR MATCHES "^aarch64")
+  set(PNG_ARM_NEON_POSSIBLE_VALUES check on off)
+  set(PNG_ARM_NEON "check" CACHE STRING "Enable ARM NEON optimizations:
+     check: (default) use internal checking code;
+     off: disable the optimizations;
+     on: turn on unconditionally.")
+  set_property(CACHE PNG_ARM_NEON PROPERTY STRINGS
+     ${PNG_ARM_NEON_POSSIBLE_VALUES})
+  list(FIND PNG_ARM_NEON_POSSIBLE_VALUES ${PNG_ARM_NEON} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+            "PNG_ARM_NEON must be one of [${PNG_ARM_NEON_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_ARM_NEON} STREQUAL "off")
+    set(libpng_arm_sources
+      arm/arm_init.c
+      arm/filter_neon.S
+      arm/filter_neon_intrinsics.c
+      arm/palette_neon_intrinsics.c)
+
+    if(${PNG_ARM_NEON} STREQUAL "on")
+      add_definitions(-DPNG_ARM_NEON_OPT=2)
+    elseif(${PNG_ARM_NEON} STREQUAL "check")
+      add_definitions(-DPNG_ARM_NEON_CHECK_SUPPORTED)
+    endif()
+  else()
+    add_definitions(-DPNG_ARM_NEON_OPT=0)
+  endif()
+endif()
+
+# set definitions and sources for powerpc
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^powerpc*" OR
+   CMAKE_SYSTEM_PROCESSOR MATCHES "^ppc64*")
+  set(PNG_POWERPC_VSX_POSSIBLE_VALUES on off)
+  set(PNG_POWERPC_VSX "on" CACHE STRING "Enable POWERPC VSX optimizations:
+     off: disable the optimizations.")
+  set_property(CACHE PNG_POWERPC_VSX PROPERTY STRINGS
+     ${PNG_POWERPC_VSX_POSSIBLE_VALUES})
+  list(FIND PNG_POWERPC_VSX_POSSIBLE_VALUES ${PNG_POWERPC_VSX} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+            "PNG_POWERPC_VSX must be one of [${PNG_POWERPC_VSX_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_POWERPC_VSX} STREQUAL "off")
+    set(libpng_powerpc_sources
+      powerpc/powerpc_init.c
+      powerpc/filter_vsx_intrinsics.c)
+    if(${PNG_POWERPC_VSX} STREQUAL "on")
+      add_definitions(-DPNG_POWERPC_VSX_OPT=2)
+    endif()
+  else()
+    add_definitions(-DPNG_POWERPC_VSX_OPT=0)
+  endif()
+endif()
+
+# set definitions and sources for intel
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^i?86" OR
+   CMAKE_SYSTEM_PROCESSOR MATCHES "^x86_64*")
+  set(PNG_INTEL_SSE_POSSIBLE_VALUES on off)
+  set(PNG_INTEL_SSE "on" CACHE STRING "Enable INTEL_SSE optimizations:
+     off: disable the optimizations")
+  set_property(CACHE PNG_INTEL_SSE PROPERTY STRINGS
+     ${PNG_INTEL_SSE_POSSIBLE_VALUES})
+  list(FIND PNG_INTEL_SSE_POSSIBLE_VALUES ${PNG_INTEL_SSE} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+            "PNG_INTEL_SSE must be one of [${PNG_INTEL_SSE_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_INTEL_SSE} STREQUAL "off")
+    set(libpng_intel_sources
+      intel/intel_init.c
+      intel/filter_sse2_intrinsics.c)
+    if(${PNG_INTEL_SSE} STREQUAL "on")
+      add_definitions(-DPNG_INTEL_SSE_OPT=1)
+    endif()
+  else()
+    add_definitions(-DPNG_INTEL_SSE_OPT=0)
+  endif()
+endif()
+
+# set definitions and sources for MIPS
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "mipsel*" OR
+   CMAKE_SYSTEM_PROCESSOR MATCHES "mips64el*")
+  set(PNG_MIPS_MSA_POSSIBLE_VALUES on off)
+  set(PNG_MIPS_MSA "on" CACHE STRING "Enable MIPS_MSA optimizations:
+     off: disable the optimizations")
+  set_property(CACHE PNG_MIPS_MSA PROPERTY STRINGS
+     ${PNG_MIPS_MSA_POSSIBLE_VALUES})
+  list(FIND PNG_MIPS_MSA_POSSIBLE_VALUES ${PNG_MIPS_MSA} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+            "PNG_MIPS_MSA must be one of [${PNG_MIPS_MSA_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_MIPS_MSA} STREQUAL "off")
+    set(libpng_mips_sources
+      mips/mips_init.c
+      mips/filter_msa_intrinsics.c)
+    if(${PNG_MIPS_MSA} STREQUAL "on")
+      add_definitions(-DPNG_MIPS_MSA_OPT=2)
+    endif()
+  else()
+    add_definitions(-DPNG_MIPS_MSA_OPT=0)
+  endif()
+endif()
+
+else(PNG_HARDWARE_OPTIMIZATIONS)
+
+# set definitions and sources for arm
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm" OR
+   CMAKE_SYSTEM_PROCESSOR MATCHES "^aarch64")
+  add_definitions(-DPNG_ARM_NEON_OPT=0)
+endif()
+
+# set definitions and sources for powerpc
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^powerpc*" OR
+   CMAKE_SYSTEM_PROCESSOR MATCHES "^ppc64*")
+  add_definitions(-DPNG_POWERPC_VSX_OPT=0)
+endif()
+
+# set definitions and sources for intel
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^i?86" OR
+   CMAKE_SYSTEM_PROCESSOR MATCHES "^x86_64*")
+  add_definitions(-DPNG_INTEL_SSE_OPT=0)
+endif()
+
+# set definitions and sources for MIPS
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "mipsel*" OR
+   CMAKE_SYSTEM_PROCESSOR MATCHES "mips64el*")
+  add_definitions(-DPNG_MIPS_MSA_OPT=0)
+endif()
+
+endif(PNG_HARDWARE_OPTIMIZATIONS)
+
 # SET LIBNAME
 set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR})
 
@@ -124,17 +251,17 @@ function(symbol_prefix)
   foreach(line ${OUT})
     string(REGEX MATCH "^PREFIX=" found_match "${line}")
     if(found_match)
-      STRING(REGEX REPLACE "^PREFIX=(.*\)" "\\1" prefix "${line}")
+      string(REGEX REPLACE "^PREFIX=(.*\)" "\\1" prefix "${line}")
       string(REGEX MATCH "__USER_LABEL_PREFIX__" found_match "${prefix}")
       if(found_match)
-        STRING(REGEX REPLACE "(.*)__USER_LABEL_PREFIX__(.*)" "\\1\\2" prefix "${prefix}")
+        string(REGEX REPLACE "(.*)__USER_LABEL_PREFIX__(.*)" "\\1\\2" prefix "${prefix}")
       endif()
       set(SYMBOL_PREFIX "${prefix}")
     endif()
   endforeach()
 
-    message(STATUS "Symbol prefix: ${SYMBOL_PREFIX}")
-    set(SYMBOL_PREFIX "${SYMBOL_PREFIX}" PARENT_SCOPE)
+  message(STATUS "Symbol prefix: ${SYMBOL_PREFIX}")
+  set(SYMBOL_PREFIX "${SYMBOL_PREFIX}" PARENT_SCOPE)
 endfunction()
 
 if(UNIX)
@@ -145,7 +272,7 @@ find_program(AWK NAMES gawk awk)
 
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
 
-if(NOT AWK)
+if(NOT AWK OR ANDROID)
   # No awk available to generate sources; use pre-built pnglibconf.h
   configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt
                  ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h)
@@ -159,11 +286,11 @@ else()
     set(oneValueArgs INPUT OUTPUT)
     set(multiValueArgs DEPENDS)
     cmake_parse_arguments(_GC "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
-    if (NOT _GC_INPUT)
-      message(FATAL_ERROR "Invalid arguments.  generate_out requires input.")
+    if(NOT _GC_INPUT)
+      message(FATAL_ERROR "generate_chk: Missing INPUT argument")
     endif()
-    if (NOT _GC_OUTPUT)
-      message(FATAL_ERROR "Invalid arguments.  generate_out requires output.")
+    if(NOT _GC_OUTPUT)
+      message(FATAL_ERROR "generate_chk: Missing OUTPUT argument")
     endif()
 
     add_custom_command(OUTPUT "${_GC_OUTPUT}"
@@ -182,11 +309,11 @@ else()
     set(oneValueArgs INPUT OUTPUT)
     set(multiValueArgs DEPENDS)
     cmake_parse_arguments(_GO "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
-    if (NOT _GO_INPUT)
-      message(FATAL_ERROR "Invalid arguments.  generate_out requires input.")
+    if(NOT _GO_INPUT)
+      message(FATAL_ERROR "generate_out: Missing INPUT argument")
     endif()
-    if (NOT _GO_OUTPUT)
-      message(FATAL_ERROR "Invalid arguments.  generate_out requires output.")
+    if(NOT _GO_OUTPUT)
+      message(FATAL_ERROR "generate_out: Missing OUTPUT argument")
     endif()
 
     add_custom_command(OUTPUT "${_GO_OUTPUT}"
@@ -205,8 +332,8 @@ else()
     set(oneValueArgs OUTPUT)
     set(multiValueArgs DEPENDS)
     cmake_parse_arguments(_GSO "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
-    if (NOT _GSO_OUTPUT)
-      message(FATAL_ERROR "Invalid arguments.  generate_source requires output.")
+    if(NOT _GSO_OUTPUT)
+      message(FATAL_ERROR "generate_source: Missing OUTPUT argument")
     endif()
 
     add_custom_command(OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${_GSO_OUTPUT}"
@@ -307,7 +434,7 @@ else()
                     WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
 
   # A single target handles generation of all generated files.  If
-  # they are dependend upon separately by multiple targets, this
+  # they are depended upon separately by multiple targets, this
   # confuses parallel make (it would require a separate top-level
   # target for each file to track the dependencies properly).
   add_custom_target(genfiles DEPENDS
@@ -324,7 +451,7 @@ else()
     "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
     "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
     "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out")
-endif(NOT AWK)
+endif(NOT AWK OR ANDROID)
 
 # OUR SOURCES
 set(libpng_public_hdrs
@@ -338,7 +465,7 @@ set(libpng_private_hdrs
   pnginfo.h
   pngstruct.h
 )
-if(AWK)
+if(AWK AND NOT ANDROID)
   list(APPEND libpng_private_hdrs "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h")
 endif()
 set(libpng_sources
@@ -359,6 +486,10 @@ set(libpng_sources
   pngwrite.c
   pngwtran.c
   pngwutil.c
+  ${libpng_arm_sources}
+  ${libpng_intel_sources}
+  ${libpng_mips_sources}
+  ${libpng_powerpc_sources}
 )
 set(pngtest_sources
   pngtest.c
@@ -384,7 +515,7 @@ set(png_fix_itxt_sources
 
 if(MSVC)
   add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
-endif(MSVC)
+endif()
 
 if(PNG_DEBUG)
   add_definitions(-DPNG_DEBUG)
@@ -464,7 +595,7 @@ if(NOT PNG_LIB_TARGETS)
   message(SEND_ERROR
     "No library variant selected to build. "
     "Please enable at least one of the following options: "
-    " PNG_STATIC, PNG_SHARED, PNG_FRAMEWORK")
+    "PNG_STATIC, PNG_SHARED, PNG_FRAMEWORK")
 endif()
 
 if(PNG_SHARED AND WIN32)
@@ -477,11 +608,11 @@ function(png_add_test)
   set(multiValueArgs OPTIONS FILES)
   cmake_parse_arguments(_PAT "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
 
-  if (NOT _PAT_NAME)
-    message(FATAL_ERROR "Invalid arguments.  png_add_test requires name.")
+  if(NOT _PAT_NAME)
+    message(FATAL_ERROR "png_add_test: Missing NAME argument")
   endif()
-  if (NOT _PAT_COMMAND)
-    message(FATAL_ERROR "Invalid arguments.  png_add_test requires command.")
+  if(NOT _PAT_COMMAND)
+    message(FATAL_ERROR "png_add_test: Missing COMMAND argument")
   endif()
 
   set(TEST_OPTIONS "${_PAT_OPTIONS}")
@@ -489,19 +620,11 @@ function(png_add_test)
 
   configure_file("${CMAKE_CURRENT_SOURCE_DIR}/scripts/test.cmake.in"
                  "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake" @ONLY)
-  if(CMAKE_MAJOR_VERSION GREATER 2) # have generator expressions
-    add_test(NAME "${_PAT_NAME}"
-             COMMAND "${CMAKE_COMMAND}"
-             "-DLIBPNG=$<TARGET_FILE:png>"
-             "-DTEST_COMMAND=$<TARGET_FILE:${_PAT_COMMAND}>"
-             -P "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake")
-  else() # old 2.x add_test; limited and won't work well on Windows
-    # Note LIBPNG is a dummy value as there are no generator expressions
-    add_test("${_PAT_NAME}" "${CMAKE_COMMAND}"
-             "-DLIBPNG=${CMAKE_CURRENT_BINARY_DIR}/libpng.so"
-             "-DTEST_COMMAND=./${_PAT_COMMAND}"
-             -P "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake")
-  endif()
+  add_test(NAME "${_PAT_NAME}"
+           COMMAND "${CMAKE_COMMAND}"
+           "-DLIBPNG=$<TARGET_FILE:png>"
+           "-DTEST_COMMAND=$<TARGET_FILE:${_PAT_COMMAND}>"
+           -P "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake")
 endfunction()
 
 if(PNG_TESTS AND PNG_SHARED)
@@ -566,11 +689,11 @@ if(PNG_TESTS AND PNG_SHARED)
         set(TEST_PNG_VALID TRUE)
 
         if(TEST_PNG_ALPHA)
-          if (NOT "${alpha_type}" STREQUAL "alpha")
+          if(NOT "${alpha_type}" STREQUAL "alpha")
             set(TEST_PNG_VALID FALSE)
           endif()
         else()
-          if ("${alpha_type}" STREQUAL "alpha")
+          if("${alpha_type}" STREQUAL "alpha")
             set(TEST_PNG_VALID FALSE)
           endif()
         endif()
@@ -634,31 +757,51 @@ if(PNG_SHARED)
   list(APPEND PNG_BIN_TARGETS png-fix-itxt)
 endif()
 
-# Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set
-IF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
-  SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib")
-ENDIF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
-
 # Set a variable with CMake code which:
 # Creates a symlink from src to dest (if possible) or alternatively
 # copies if different.
-macro(CREATE_SYMLINK SRC_FILE DEST_FILE)
-  FILE(REMOVE ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
-  if(WIN32 AND NOT CYGWIN AND NOT MSYS)
-    ADD_CUSTOM_COMMAND(
-        OUTPUT ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}   ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
-        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}
-        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
-        DEPENDS ${PNG_LIB_TARGETS}
-        )
-    ADD_CUSTOM_TARGET(${DEST_FILE}_COPY ALL DEPENDS ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
-  else(WIN32 AND NOT CYGWIN AND NOT MSYS)
-    get_filename_component(LINK_TARGET "${SRC_FILE}" NAME)
-    execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_LIBRARY_OUTPUT_DIRECTORY})
-    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
-    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
-  endif(WIN32 AND NOT CYGWIN AND NOT MSYS)
-endmacro()
+include(CMakeParseArguments)
+
+function(create_symlink DEST_FILE)
+
+  cmake_parse_arguments(S "" "FILE;TARGET" "" ${ARGN})
+
+  if(NOT S_TARGET AND NOT S_FILE)
+    message(FATAL_ERROR "create_symlink: Missing TARGET or FILE argument")
+  endif()
+
+  if(S_TARGET AND S_FILE)
+    message(FATAL_ERROR "create_symlink: Both source file ${S_FILE} and build target ${S_TARGET} arguments are present; can only have one.")
+  endif()
+
+  if(S_FILE)
+    # If we don't need to symlink something that's coming from a build target,
+    # we can go ahead and symlink/copy at configure time.
+    if(CMAKE_HOST_WIN32 AND NOT CYGWIN)
+      execute_process(
+        COMMAND "${CMAKE_COMMAND}" -E copy_if_different ${S_FILE} ${DEST_FILE}
+        WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+    else()
+      execute_process(
+        COMMAND ${CMAKE_COMMAND} -E create_symlink ${S_FILE} ${DEST_FILE}
+        WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+    endif()
+  endif()
+
+  if(S_TARGET)
+    # We need to use generator expressions, which can be a bit tricky, so for
+    # simplicity make the symlink a POST_BUILD step and use the TARGET
+    # signature of add_custom_command.
+    if(CMAKE_HOST_WIN32 AND NOT CYGWIN)
+      add_custom_command(TARGET ${S_TARGET} POST_BUILD
+        COMMAND "${CMAKE_COMMAND}" -E copy_if_different $<TARGET_LINKER_FILE_NAME:${S_TARGET}> $<TARGET_LINKER_FILE_DIR:${S_TARGET}>/${DEST_FILE})
+    else()
+      add_custom_command(TARGET ${S_TARGET} POST_BUILD
+        COMMAND "${CMAKE_COMMAND}" -E create_symlink $<TARGET_LINKER_FILE_NAME:${S_TARGET}> $<TARGET_LINKER_FILE_DIR:${S_TARGET}>/${DEST_FILE})
+    endif()
+  endif()
+
+endfunction()
 
 # Create source generation scripts.
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/genchk.cmake.in
@@ -668,111 +811,97 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/genout.cmake.in
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/gensrc.cmake.in
                ${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake @ONLY)
 
-
 # libpng is a library so default to 'lib'
 if(NOT DEFINED CMAKE_INSTALL_LIBDIR)
   set(CMAKE_INSTALL_LIBDIR lib)
-endif(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+endif()
 
 # CREATE PKGCONFIG FILES
-# we use the same files like ./configure, so we have to set its vars
+# We use the same files like ./configure, so we have to set its vars.
 # Only do this on Windows for Cygwin - the files don't make much sense outside
-# a UNIX look alike
+# of a UNIX look-alike.
 if(NOT WIN32 OR CYGWIN OR MINGW)
   set(prefix      ${CMAKE_INSTALL_PREFIX})
   set(exec_prefix ${CMAKE_INSTALL_PREFIX})
-  set(libdir      ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
-  set(includedir  ${CMAKE_INSTALL_PREFIX}/include)
+  set(libdir      ${CMAKE_INSTALL_FULL_LIBDIR})
+  set(includedir  ${CMAKE_INSTALL_FULL_INCLUDEDIR})
   set(LIBS        "-lz -lm")
   configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
     ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY)
-  CREATE_SYMLINK(${PNGLIB_NAME}.pc libpng.pc)
+  create_symlink(libpng.pc FILE ${PNGLIB_NAME}.pc)
 
   configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in
     ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY)
-  CREATE_SYMLINK(${PNGLIB_NAME}-config libpng-config)
-endif(NOT WIN32 OR CYGWIN OR MINGW)
+  create_symlink(libpng-config FILE ${PNGLIB_NAME}-config)
+endif()
 
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(png PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.26
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.36
     VERSION 16.${PNGLIB_RELEASE}.0
     SOVERSION 16
     CLEAN_DIRECT_OUTPUT 1)
 endif()
 
-# If CMake > 2.4.x, we set a variable used below to export
-# targets to an export file.
-# TODO: Use VERSION_GREATER after our cmake_minimum_required >= 2.6.2
-if(CMAKE_MAJOR_VERSION GREATER 1 AND CMAKE_MINOR_VERSION GREATER 4)
-  set(PNG_EXPORT_RULE EXPORT libpng)
-elseif(CMAKE_MAJOR_VERSION GREATER 2) # future proof
-  set(PNG_EXPORT_RULE EXPORT libpng)
-endif()
-
 # INSTALL
-if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
+if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL)
   install(TARGETS ${PNG_LIB_TARGETS}
-      ${PNG_EXPORT_RULE}
-      RUNTIME DESTINATION bin
-      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
-      FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
+          EXPORT libpng
+          RUNTIME DESTINATION bin
+          LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+          ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+          FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
   if(PNG_SHARED)
     # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin
     if(CYGWIN OR MINGW)
-       get_target_property(BUILD_TARGET_LOCATION png LOCATION_${CMAKE_BUILD_TYPE})
-       CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_IMPORT_LIBRARY_SUFFIX})
-       install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}
-         DESTINATION ${CMAKE_INSTALL_LIBDIR})
-    endif(CYGWIN OR MINGW)
+      create_symlink(libpng${CMAKE_IMPORT_LIBRARY_SUFFIX} TARGET png)
+      install(FILES $<TARGET_LINKER_FILE_DIR:png>/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}
+              DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif()
 
     if(NOT WIN32)
-      get_target_property(BUILD_TARGET_LOCATION png LOCATION_${CMAKE_BUILD_TYPE})
-      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
-      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
-         DESTINATION ${CMAKE_INSTALL_LIBDIR})
-    endif(NOT WIN32)
-  endif(PNG_SHARED)
+      create_symlink(libpng${CMAKE_SHARED_LIBRARY_SUFFIX} TARGET png)
+      install(FILES $<TARGET_LINKER_FILE_DIR:png>/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
+              DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif()
+  endif()
 
   if(PNG_STATIC)
     if(NOT WIN32 OR CYGWIN OR MINGW)
-      get_target_property(BUILD_TARGET_LOCATION png_static LOCATION_${CMAKE_BUILD_TYPE})
-      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
-      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
-         DESTINATION ${CMAKE_INSTALL_LIBDIR})
-    endif(NOT WIN32 OR CYGWIN OR MINGW)
- endif()
+      create_symlink(libpng${CMAKE_STATIC_LIBRARY_SUFFIX} TARGET png_static)
+      install(FILES $<TARGET_LINKER_FILE_DIR:png_static>/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
+              DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif()
+  endif()
 endif()
 
-if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
-  install(FILES ${libpng_public_hdrs}   DESTINATION include)
-  install(FILES ${libpng_public_hdrs}   DESTINATION include/${PNGLIB_NAME})
+if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL)
+  install(FILES ${libpng_public_hdrs} DESTINATION include)
+  install(FILES ${libpng_public_hdrs} DESTINATION include/${PNGLIB_NAME})
 endif()
-if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL )
+if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL)
   if(NOT WIN32 OR CYGWIN OR MINGW)
     install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config DESTINATION bin)
-    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
-            DESTINATION bin)
-  endif(NOT WIN32 OR CYGWIN OR MINGW)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config DESTINATION bin)
+  endif()
 endif()
 
-if(NOT SKIP_INSTALL_PROGRAMS AND NOT SKIP_INSTALL_ALL )
+if(NOT SKIP_INSTALL_PROGRAMS AND NOT SKIP_INSTALL_ALL)
   install(TARGETS ${PNG_BIN_TARGETS}
-      RUNTIME DESTINATION bin)
+          RUNTIME DESTINATION bin)
 endif()
 
-if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
+if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL)
   # Install man pages
   if(NOT PNG_MAN_DIR)
     set(PNG_MAN_DIR "share/man")
   endif()
-  install(FILES libpng.3 libpngpf.3      DESTINATION ${PNG_MAN_DIR}/man3)
-  install(FILES png.5                    DESTINATION ${PNG_MAN_DIR}/man5)
+  install(FILES libpng.3 libpngpf.3 DESTINATION ${PNG_MAN_DIR}/man3)
+  install(FILES png.5 DESTINATION ${PNG_MAN_DIR}/man5)
   # Install pkg-config files
-  if(NOT WIN32 OR CYGWIN OR MINGW)
+  if(NOT CMAKE_HOST_WIN32 OR CYGWIN OR MINGW)
     install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc
             DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
     install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config
@@ -781,12 +910,11 @@ if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
             DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
     install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
             DESTINATION bin)
-  endif(NOT WIN32 OR CYGWIN OR MINGW)
+  endif()
 endif()
 
-# On versions of CMake that support it, create an export file CMake
-# users can include() to import our targets
-if(PNG_EXPORT_RULE AND NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL )
+# Create an export file that CMake users can include() to import our targets.
+if(NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL)
   install(EXPORT libpng DESTINATION lib/libpng FILE lib${PNG_LIB_NAME}.cmake)
 endif()
 
@@ -801,4 +929,3 @@ endif()
 # to create msvc import lib for mingw compiled shared lib
 # pexports libpng.dll > libpng.def
 # lib /def:libpng.def /machine:x86
-

INSTALL

@@ -16,10 +16,11 @@ Contents
       XI. Prepending a prefix to exported symbols
      XII. Configuring for compiler xxx:
     XIII. Removing unwanted object code
-     XIV. Changes to the build and configuration of libpng in libpng-1.5.x
-      XV. Setjmp/longjmp issues
-     XVI. Common linking failures
-    XVII. Other sources of information about libpng
+     XIV. Enabling or disabling hardware optimizations
+      XV. Changes to the build and configuration of libpng in libpng-1.5.x
+     XVI. Setjmp/longjmp issues
+    XVII. Common linking failures
+   XVIII. Other sources of information about libpng
 
 I. Simple installation
 
@@ -78,8 +79,8 @@ Or you can use one of the "projects" in the "projects" directory.
 
 Before installing libpng, you must first install zlib, if it
 is not already on your system.  zlib can usually be found
-wherever you got libpng; otherwise go to http://zlib.net.  You can place
-zlib in the same directory as libpng or in another directory.
+wherever you got libpng; otherwise go to https://zlib.net/.  You can
+place zlib in the same directory as libpng or in another directory.
 
 If your system already has a preinstalled zlib you will still need
 to have access to the zlib.h and zconf.h include files that
@@ -281,7 +282,57 @@ library to fail if they call functions not available in your library.
 The size of the library itself should not be an issue, because only
 those sections that are actually used will be loaded into memory.
 
-XIV. Changes to the build and configuration of libpng in libpng-1.5.x
+XIV. Enabling or disabling hardware optimizations
+
+Certain hardware capabilities, such as the Intel SSE instructions,
+are normally detected at run time. Enable them with configure options
+such as one of
+
+   --enable-arm-neon=yes
+   --enable-mips-msa=yes
+   --enable-intel-sse=yes
+   --enable-powerpc-vsx=yes
+
+or enable them all at once with
+
+   --enable-hardware-optimizations=yes
+
+or, if you are not using "configure", you can use one
+or more of
+
+   CPPFLAGS += "-DPNG_ARM_NEON"
+   CPPFLAGS += "-DPNG_MIPS_MSA"
+   CPPFLAGS += "-DPNG_INTEL_SSE"
+   CPPFLAGS += "-DPNG_POWERPC_VSX"
+
+See for example scripts/makefile.linux-opt
+
+If you wish to avoid using them,
+you can disable them via the configure option
+
+   --disable-hardware-optimizations
+
+to disable them all, or
+
+   --enable-intel-sse=no
+
+to disable a particular one,
+or via compiler-command options such as
+
+   CPPFLAGS += "-DPNG_ARM_NEON_OPT=0, -DPNG_MIPS_MSA_OPT=0,
+   -DPNG_INTEL_SSE_OPT=0, -DPNG_POWERPC_VSX_OPT=0"
+
+If you are using cmake, hardware optimizations are "on"
+by default. To disable them, use
+
+    cmake . -DPNG_ARM_NEON=no -DPNG_INTEL_SSE=no \
+            -DPNG_MIPS_MSA=no -DPNG_POWERPC_VSX=no
+
+or disable them all at once with
+
+    cmake . -DPNG_HARDWARE_OPTIMIZATIONS=no
+
+XV. Changes to the build and configuration of libpng in libpng-1.5.x
 
 Details of internal changes to the library code can be found in the CHANGES
 file and in the GIT repository logs.  These will be of no concern to the vast
@@ -372,7 +423,7 @@ $PREFIX/include directory).  Do not edit pnglibconf.h after you have built
 libpng, because than the settings would not accurately reflect the settings
 that were used to build libpng.
 
-XV. Setjmp/longjmp issues
+XVI. Setjmp/longjmp issues
 
 Libpng uses setjmp()/longjmp() for error handling.  Unfortunately setjmp()
 is known to be not thread-safe on some platforms and we don't know of
@@ -390,7 +441,7 @@ This requires setjmp/longjmp, so you must either build the library
 with PNG_SETJMP_SUPPORTED defined, or with PNG_SIMPLIFIED_READ_SUPPORTED
 and PNG_SIMPLIFIED_WRITE_SUPPORTED undefined.
 
-XVI. Common linking failures
+XVII. Common linking failures
 
 If your application fails to find libpng or zlib entries while linking:
 
@@ -402,7 +453,7 @@ If your application fails to find libpng or zlib entries while linking:
   If you are using the vstudio project, observe the WARNING in
   project/vstudio/README.txt.
 
-XVII. Other sources of information about libpng:
+XVIII. Other sources of information about libpng:
 
 Further information can be found in the README and libpng-manual.txt
 files, in the individual makefiles, in png.h, and the manual pages

LICENSE

@@ -1,50 +1,82 @@
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
+=========================================
 
-This copy of the libpng notices is provided for your convenience.  In case of
-any discrepancy between this copy and the notices in the file png.h that is
-included in the libpng distribution, the latter shall prevail.
+PNG Reference Library License version 2
+---------------------------------------
 
-COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+ * Copyright (c) 1995-2018 The PNG Reference Library Authors.
+ * Copyright (c) 2018 Cosmin Truta.
+ * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
+ * Copyright (c) 1996-1997 Andreas Dilger.
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 
-If you modify libpng you may insert additional notices immediately following
-this sentence.
+The software is supplied "as is", without warranty of any kind,
+express or implied, including, without limitation, the warranties
+of merchantability, fitness for a particular purpose, title, and
+non-infringement.  In no even shall the Copyright owners, or
+anyone distributing the software, be liable for any damages or
+other liability, whether in contract, tort or otherwise, arising
+from, out of, or in connection with the software, or the use or
+other dealings in the software, even if advised of the possibility
+of such damage.
 
-This code is released under the libpng license.
+Permission is hereby granted to use, copy, modify, and distribute
+this software, or portions hereof, for any purpose, without fee,
+subject to the following restrictions:
 
-libpng versions 1.0.7, July 1, 2000 through 1.6.26, October 20, 2016 are
-Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
+ 1. The origin of this software must not be misrepresented; you
+    must not claim that you wrote the original software.  If you
+    use this software in a product, an acknowledgment in the product
+    documentation would be appreciated, but is not required.
+
+ 2. Altered source versions must be plainly marked as such, and must
+    not be misrepresented as being the original software.
+
+ 3. This Copyright notice may not be removed or altered from any
+    source or altered source distribution.
+
+
+PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
+-----------------------------------------------------------------------
+
+libpng versions 1.0.7, July 1, 2000 through 1.6.35, July 15, 2018 are
+Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
 added to the list of Contributing Authors:
 
-   Simon-Pierre Cadieux
-   Eric S. Raymond
-   Mans Rullgard
-   Cosmin Truta
-   Gilles Vollant
-   James Yu
+    Simon-Pierre Cadieux
+    Eric S. Raymond
+    Mans Rullgard
+    Cosmin Truta
+    Gilles Vollant
+    James Yu
+    Mandar Sahastrabuddhe
+    Google Inc.
+    Vadim Barkov
 
 and with the following additions to the disclaimer:
 
-   There is no warranty against interference with your enjoyment of the
-   library or against infringement.  There is no warranty that our
-   efforts or the library will fulfill any of your particular purposes
-   or needs.  This library is provided with all faults, and the entire
-   risk of satisfactory quality, performance, accuracy, and effort is with
-   the user.
+    There is no warranty against interference with your enjoyment of
+    the library or against infringement.  There is no warranty that our
+    efforts or the library will fulfill any of your particular purposes
+    or needs.  This library is provided with all faults, and the entire
+    risk of satisfactory quality, performance, accuracy, and effort is
+    with the user.
 
 Some files in the "contrib" directory and some configure-generated
-files that are distributed with libpng have other copyright owners and
+files that are distributed with libpng have other copyright owners, and
 are released under other open source licenses.
 
 libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
 Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
 libpng-0.96, and are distributed according to the same disclaimer and
-license as libpng-0.96, with the following individuals added to the list
-of Contributing Authors:
+license as libpng-0.96, with the following individuals added to the
+list of Contributing Authors:
 
-   Tom Lane
-   Glenn Randers-Pehrson
-   Willem van Schaik
+    Tom Lane
+    Glenn Randers-Pehrson
+    Willem van Schaik
 
 libpng versions 0.89, June 1996, through 0.96, May 1997, are
 Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
@@ -52,14 +84,14 @@ and are distributed according to the same disclaimer and license as
 libpng-0.88, with the following individuals added to the list of
 Contributing Authors:
 
-   John Bowler
-   Kevin Bracey
-   Sam Bushell
-   Magnus Holmgren
-   Greg Roelofs
-   Tom Tanner
+    John Bowler
+    Kevin Bracey
+    Sam Bushell
+    Magnus Holmgren
+    Greg Roelofs
+    Tom Tanner
 
-Some files in the "scripts" directory have other copyright owners
+Some files in the "scripts" directory have other copyright owners,
 but are released under this license.
 
 libpng versions 0.5, May 1995, through 0.88, January 1996, are
@@ -68,63 +100,35 @@ Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 For the purposes of this copyright and license, "Contributing Authors"
 is defined as the following set of individuals:
 
-   Andreas Dilger
-   Dave Martindale
-   Guy Eric Schalnat
-   Paul Schmidt
-   Tim Wegner
+    Andreas Dilger
+    Dave Martindale
+    Guy Eric Schalnat
+    Paul Schmidt
+    Tim Wegner
 
-The PNG Reference Library is supplied "AS IS".  The Contributing Authors
-and Group 42, Inc. disclaim all warranties, expressed or implied,
-including, without limitation, the warranties of merchantability and of
-fitness for any purpose.  The Contributing Authors and Group 42, Inc.
-assume no liability for direct, indirect, incidental, special, exemplary,
-or consequential damages, which may result from the use of the PNG
-Reference Library, even if advised of the possibility of such damage.
+The PNG Reference Library is supplied "AS IS".  The Contributing
+Authors and Group 42, Inc. disclaim all warranties, expressed or
+implied, including, without limitation, the warranties of
+merchantability and of fitness for any purpose.  The Contributing
+Authors and Group 42, Inc. assume no liability for direct, indirect,
+incidental, special, exemplary, or consequential damages, which may
+result from the use of the PNG Reference Library, even if advised of
+the possibility of such damage.
 
 Permission is hereby granted to use, copy, modify, and distribute this
 source code, or portions hereof, for any purpose, without fee, subject
 to the following restrictions:
 
-  1. The origin of this source code must not be misrepresented.
+ 1. The origin of this source code must not be misrepresented.
 
-  2. Altered versions must be plainly marked as such and must not
-     be misrepresented as being the original source.
+ 2. Altered versions must be plainly marked as such and must not
+    be misrepresented as being the original source.
 
-  3. This Copyright notice may not be removed or altered from any
-     source or altered source distribution.
+ 3. This Copyright notice may not be removed or altered from any
+    source or altered source distribution.
 
-The Contributing Authors and Group 42, Inc. specifically permit, without
-fee, and encourage the use of this source code as a component to
-supporting the PNG file format in commercial products.  If you use this
-source code in a product, acknowledgment is not required but would be
-appreciated.
-
-END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
-
-TRADEMARK:
-
-The name "libpng" has not been registered by the Copyright owner
-as a trademark in any jurisdiction.  However, because libpng has
-been distributed and maintained world-wide, continually since 1995,
-the Copyright owner claims "common-law trademark protection" in any
-jurisdiction where common-law trademark is recognized.
-
-OSI CERTIFICATION:
-
-Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
-a certification mark of the Open Source Initiative. OSI has not addressed
-the additional disclaimers inserted at version 1.0.7.
-
-EXPORT CONTROL:
-
-The Copyright owner believes that the Export Control Classification
-Number (ECCN) for libpng is EAR99, which means not subject to export
-controls or International Traffic in Arms Regulations (ITAR) because
-it is open source, publicly available software, that does not contain
-any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
-734.7(b).
-
-Glenn Randers-Pehrson
-glennrp at users.sourceforge.net
-October 20, 2016
+The Contributing Authors and Group 42, Inc. specifically permit,
+without fee, and encourage the use of this source code as a component
+to supporting the PNG file format in commercial products.  If you use
+this source code in a product, acknowledgment is not required but would
+be appreciated.

Makefile.am

@@ -1,7 +1,7 @@
 # Makefile.am, the source file for Makefile.in (and hence Makefile), is
 #
+# Copyright (c) 2018 Cosmin Truta
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
-# Last changed in libpng 1.6.25 [October 20, 2016]
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -60,6 +60,7 @@ pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 # set of parameters:
 TESTS =\
    tests/pngtest\
+   tests/pngtest-badpngs\
    tests/pngvalid-gamma-16-to-8 tests/pngvalid-gamma-alpha-mode\
    tests/pngvalid-gamma-background tests/pngvalid-gamma-expand16-alpha-mode\
    tests/pngvalid-gamma-expand16-background\
@@ -94,7 +95,8 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c\
 
 if PNG_ARM_NEON
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
-	arm/filter_neon.S arm/filter_neon_intrinsics.c
+	arm/filter_neon.S arm/filter_neon_intrinsics.c \
+	arm/palette_neon_intrinsics.c
 endif
 
 if PNG_MIPS_MSA
@@ -102,6 +104,16 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/mips_init.c\
 	mips/filter_msa_intrinsics.c
 endif
 
+if PNG_INTEL_SSE
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += intel/intel_init.c\
+	intel/filter_sse2_intrinsics.c
+endif
+
+if PNG_POWERPC_VSX
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += powerpc/powerpc_init.c\
+        powerpc/filter_vsx_intrinsics.c
+endif
+
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
 
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined -export-dynamic \
@@ -136,7 +148,7 @@ pkgconfig_DATA = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc
 # from those directories being included.  This only works if the configure is
 # not done in the source directory!
 EXTRA_DIST= \
-	ANNOUNCE CHANGES INSTALL LICENSE README TODO \
+	ANNOUNCE AUTHORS CHANGES INSTALL LICENSE README TODO TRADEMARK \
 	pngtest.png pngbar.png pngnow.png pngbar.jpg autogen.sh \
 	${srcdir}/contrib ${srcdir}/projects ${srcdir}/scripts \
 	$(TESTS) $(XFAIL_TESTS) tests/pngstest \

README

@@ -1,15 +1,16 @@
-README for libpng version 1.6.26 - October 20, 2016 (shared library 16.0)
-See the note about version numbers near the top of png.h
+README for libpng version 1.6.36 - December 1, 2018
+===================================================
 
+See the note about version numbers near the top of png.h.
 See INSTALL for instructions on how to install libpng.
 
 Libpng comes in several distribution formats.  Get libpng-*.tar.gz or
-libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
-or lpng*.7z or lpng*.zip if you want DOS-style line endings.
+libpng-*.tar.xz or if you want UNIX-style line endings in the text
+files, or lpng*.7z or lpng*.zip if you want DOS-style line endings.
 
 Version 0.89 was the first official release of libpng.  Don't let the
-fact that it's the first release fool you.  The libpng library has been in
-extensive use and testing since mid-1995.  By late 1997 it had
+fact that it's the first release fool you.  The libpng library has been
+in extensive use and testing since mid-1995.  By late 1997 it had
 finally gotten to the stage where there hadn't been significant
 changes to the API in some time, and people have a bad feeling about
 libraries with versions < 1.0.  Version 1.0.0 was released in
@@ -23,7 +24,7 @@ earlier versions if you are using a shared library.  The type of the
 png_uint_32, which will affect shared-library applications that use
 this function.
 
-To avoid problems with changes to the internals of png info_struct,
+To avoid problems with changes to the internals of the png info_struct,
 new APIs have been made available in 0.95 to avoid direct application
 access to info_ptr.  These functions are the png_set_<chunk> and
 png_get_<chunk> functions.  These functions should be used when
@@ -60,94 +61,59 @@ the library action on the detection of chunk CRC errors.  It is possible
 to set different actions based on whether the CRC error occurred in a
 critical or an ancillary chunk.
 
-The changes made to the library, and bugs fixed are based on discussions
-on the PNG-implement mailing list and not on material submitted
-privately to Guy, Andreas, or Glenn.  They will forward any good
-suggestions to the list.
-
-For a detailed description on using libpng, read libpng-manual.txt.  For
-examples of libpng in a program, see example.c and pngtest.c.  For usage
-information and restrictions (what little they are) on libpng, see
-png.h.  For a description on using zlib (the compression library used by
-libpng) and zlib's restrictions, see zlib.h
+For a detailed description on using libpng, read libpng-manual.txt.
+For examples of libpng in a program, see example.c and pngtest.c.  For
+usage information and restrictions (what little they are) on libpng,
+see png.h.  For a description on using zlib (the compression library
+used by libpng) and zlib's restrictions, see zlib.h
 
 I have included a general makefile, as well as several machine and
-compiler specific ones, but you may have to modify one for your own needs.
+compiler specific ones, but you may have to modify one for your own
+needs.
 
 You should use zlib 1.0.4 or later to run this, but it MAY work with
 versions as old as zlib 0.95.  Even so, there are bugs in older zlib
 versions which can cause the output of invalid compression streams for
-some images.  You will definitely need zlib 1.0.4 or later if you are
-taking advantage of the MS-DOS "far" structure allocation for the small
-and medium memory models.  You should also note that zlib is a
-compression library that is useful for more things than just PNG files.
-You can use zlib as a drop-in replacement for fread() and fwrite() if
-you are so inclined.
+some images.
 
-zlib should be available at the same place that libpng is, or at zlib.net.
+You should also note that zlib is a compression library that is useful
+for more things than just PNG files.  You can use zlib as a drop-in
+replacement for fread() and fwrite(), if you are so inclined.
+
+zlib should be available at the same place that libpng is, or at
+https://zlib.net.
 
 You may also want a copy of the PNG specification.  It is available
 as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
-these at http://www.libpng.org/pub/png/documents/
+these at http://www.libpng.org/pub/png/pngdocs.html .
 
-This code is currently being archived at libpng.sf.net in the
-[DOWNLOAD] area, and at ftp://ftp.simplesystems.org.  If you can't find it
-in any of those places, e-mail me, and I'll help you find it.
+This code is currently being archived at libpng.sourceforge.io in the
+[DOWNLOAD] area, and at http://libpng.download/src .
 
-I am not a lawyer, but I believe that the Export Control Classification
-Number (ECCN) for libpng is EAR99, which means not subject to export
-controls or International Traffic in Arms Regulations (ITAR) because it
-is open source, publicly available software, that does not contain any
-encryption software.  See the EAR, paragraphs 734.3(b)(3) and 734.7(b).
-
-If you have any code changes, requests, problems, etc., please e-mail
-them to me.  Also, I'd appreciate any make files or project files,
-and any modifications you needed to make to get libpng to compile,
-along with a #define variable to tell what compiler/system you are on.
-If you needed to add transformations to libpng, or wish libpng would
-provide the image in a different way, drop me a note (and code, if
-possible), so I can consider supporting the transformation.
-Finally, if you get any warning messages when compiling libpng
-(note: not zlib), and they are easy to fix, I'd appreciate the
-fix.  Please mention "libpng" somewhere in the subject line.  Thanks.
-
-This release was created and will be supported by myself (of course
-based in a large way on Guy's and Andreas' earlier work), and the PNG
+This release, based in a large way on Glenn's, Guy's and Andreas'
+earlier work, was created and will be supported by myself and the PNG
 development group.
 
 Send comments/corrections/commendations to png-mng-implement at
 lists.sourceforge.net (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
-to subscribe) or to glennrp at users.sourceforge.net
+to subscribe).
 
-You can't reach Guy, the original libpng author, at the addresses
-given in previous versions of this document.  He and Andreas will
-read mail addressed to the png-implement list, however.
-
-Please do not send general questions about PNG.  Send them to
-png-mng-misc at lists.sf.net (subscription required; visit
+Send general questions about the PNG specification to png-mng-misc
+at lists.sourceforge.net (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
-subscribe).  If you have a question about something
-in the PNG specification that is related to using libpng, send it
-to me.  Send me any questions that start with "I was using libpng,
-and ...".  If in doubt, send questions to me.  I'll bounce them
-to others, if necessary.
-
-Please do not send suggestions on how to change PNG.  We have
-been discussing PNG for twenty years now, and it is official and
-finished.  If you have suggestions for libpng, however, I'll
-gladly listen.  Even if your suggestion is not used immediately,
-it may be used later.
+subscribe).
 
 Files in this distribution:
 
       ANNOUNCE      =>  Announcement of this version, with recent changes
+      AUTHORS       =>  List of contributing authors
       CHANGES       =>  Description of changes between libpng versions
       KNOWNBUG      =>  List of known bugs and deficiencies
       LICENSE       =>  License to use and redistribute libpng
       README        =>  This file
       TODO          =>  Things not implemented in the current library
-      Y2KINFO       =>  Statement of Y2K compliance
+      TRADEMARK     =>  Trademark information
       example.c     =>  Example code for using libpng functions
       libpng.3      =>  manual page for libpng (includes libpng-manual.txt)
       libpng-manual.txt  =>  Description of libpng and its functions
@@ -179,14 +145,16 @@ Files in this distribution:
       pngwtran.c    =>  Write data transformations
       pngwutil.c    =>  Write utility functions
       arm           =>  Contains optimized code for the ARM platform
+      powerpc       =>  Contains optimized code for the PowerPC platform
       contrib       =>  Contributions
        arm-neon         =>  Optimized code for ARM-NEON platform
+       powerpc-vsx      =>  Optimized code for POWERPC-VSX platform
        examples         =>  Example programs
        gregbook         =>  source code for PNG reading and writing, from
                             Greg Roelofs' "PNG: The Definitive Guide",
                             O'Reilly, 1999
-       intel            =>  Optimized code for INTEL-SSE2 platform
        libtests         =>  Test programs
+       mips-msa         =>  Optimized code for MIPS-MSA platform
        pngminim         =>  Minimal decoder, encoder, and progressive decoder
                             programs demonstrating use of pngusr.dfa
        pngminus         =>  Simple pnm2png and png2pnm programs
@@ -194,6 +162,8 @@ Files in this distribution:
        testpngs
        tools            =>  Various tools
        visupng          =>  Contains a MSVC workspace for VisualPng
+      intel             =>  Optimized code for INTEL-SSE2 platform
+      mips              =>  Optimized code for MIPS platform
       projects      =>  Contains project files and workspaces for
                         building a DLL
        owatcom          =>  Contains a WATCOM project for building libpng
@@ -204,15 +174,10 @@ Files in this distribution:
       scripts       =>  Directory containing scripts for building libpng:
                             (see scripts/README.txt for the list of scripts)
 
-Good luck, and happy coding.
+Good luck, and happy coding!
 
--Glenn Randers-Pehrson (current maintainer, since 1998)
- Internet: glennrp at users.sourceforge.net
-
--Andreas Eric Dilger (former maintainer, 1996-1997)
- Internet: adilger at enel.ucalgary.ca
- Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
-
--Guy Eric Schalnat (original author and former maintainer, 1995-1996)
- (formerly of Group 42, Inc)
- Internet: gschal at infinet.com
+ * Cosmin Truta (current maintainer, since 2018)
+ * Glenn Randers-Pehrson (former maintainer, 1998-2018)
+ * Andreas Eric Dilger (former maintainer, 1996-1997)
+ * Guy Eric Schalnat (original author and former maintainer, 1995-1996)
+   (formerly of Group 42, Inc.)

TODO

@@ -1,30 +1,23 @@
-/*
 TODO - list of things to do for libpng:
 
-Final bug fixes.
-Better C++ wrapper/full C++ implementation?
-Fix problem with C++ and EXTERN "C".
-cHRM transformation.
-Remove setjmp/longjmp usage in favor of returning error codes. As a start on
-  this, minimize the use of png_error(), replacing them with
-  png_warning(); return(0; or similar.
-Palette creation.
-Add "grayscale->palette" transformation and "palette->grayscale" detection.
-Improved dithering.
-Multi-lingual error and warning message support.
-Complete sRGB transformation (presently it simply uses gamma=0.45455).
-Man pages for function calls.
-Better documentation.
-Better filter selection
-   (counting huffman bits/precompression?  filter inertia?  filter costs?).
-Histogram creation.
-Text conversion between different code pages (Latin-1 -> Mac and DOS).
-Avoid building gamma tables whenever possible.
-Use greater precision when changing to linear gamma for compositing against
-  background and doing rgb-to-gray transformation.
-Investigate pre-incremented loop counters and other loop constructions.
-Add interpolated method of handling interlacing.
-Switch to the simpler zlib (zlib/libpng) license if legally possible.
-Extend pngvalid.c to validate more of the libpng transformations.
-
-*/
+* Fix all defects (duh!)
+* Better C++ wrapper / full C++ implementation (?)
+* Fix the problems with C++ and 'extern "C"'.
+* cHRM transformation.
+* Palette creation.
+* "grayscale->palette" transformation and "palette->grayscale" detection.
+* Improved dithering.
+* Multi-lingual error and warning message support.
+* Complete sRGB transformation.  (Currently it simply uses gamma=0.45455.)
+* Man pages for function calls.
+* Better documentation.
+* Better filter selection
+  (e.g., counting huffman bits/precompression; filter inertia; filter costs).
+* Histogram creation.
+* Text conversion between different code pages (e.g., Latin-1 -> Mac).
+* Avoid building gamma tables whenever possible.
+* Greater precision in changing to linear gamma for compositing against
+  background, and in doing rgb-to-gray transformations.
+* Investigate pre-incremented loop counters and other loop constructions.
+* Interpolated method of handling interlacing.
+* More validations for libpng transformations.

TRADEMARK

@@ -0,0 +1,8 @@
+TRADEMARK
+=========
+
+The name "libpng" has not been registered by the Copyright owners
+as a trademark in any jurisdiction.  However, because libpng has
+been distributed and maintained world-wide, continually since 1995,
+the Copyright owners claim "common-law trademark protection" in any
+jurisdiction where common-law trademark is recognized.

arm/arm_init.c

@@ -1,14 +1,15 @@
 
 /* arm_init.c - NEON optimised filter functions
  *
+ * Copyright (c) 2018 Cosmin Truta
  * Copyright (c) 2014,2016 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.22 [May 26, 2016]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  */
+
 /* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are
  * called.
  */

arm/filter_neon.S

@@ -1,9 +1,9 @@
 
 /* filter_neon.S - NEON optimised filter functions
  *
- * Copyright (c) 2014 Glenn Randers-Pehrson
+ * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2014,2017 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.16 [December 22, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -16,7 +16,7 @@
 #define PNG_VERSION_INFO_ONLY
 #include "../pngpriv.h"
 
-#if defined(__linux__) && defined(__ELF__)
+#if (defined(__linux__) || defined(__FreeBSD__)) && defined(__ELF__)
 .section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
 #endif
 

arm/filter_neon_intrinsics.c

@@ -1,12 +1,11 @@
 
 /* filter_neon_intrinsics.c - NEON optimised filter functions
  *
+ * Copyright (c) 2018 Cosmin Truta
  * Copyright (c) 2014,2016 Glenn Randers-Pehrson
  * Written by James Yu <james.yu at linaro.org>, October 2013.
  * Based on filter_neon.S, written by Mans Rullgard, 2011.
  *
- * Last changed in libpng 1.6.22 [May 26, 2016]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -19,7 +18,11 @@
 /* This code requires -mfpu=neon on the command line: */
 #if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
 
-#include <arm_neon.h>
+#if defined(_MSC_VER) && defined(_M_ARM64)
+#  include <arm64_neon.h>
+#else
+#  include <arm_neon.h>
+#endif
 
 /* libpng row pointers are not necessarily aligned to any particular boundary,
  * however this code will only work with appropriate alignment.  arm/arm_init.c
@@ -33,6 +36,11 @@
  * 'type'.  This is written this way just to hide the GCC strict aliasing
  * warning; note that the code is safe because there never is an alias between
  * the input and output pointers.
+ *
+ * When compiling with MSVC ARM64, the png_ldr macro can't be passed directly
+ * to vst4_lane_u32, because of an internal compiler error inside MSVC.
+ * To avoid this compiler bug, we use a temporary variable (vdest_val) to store
+ * the result of png_ldr.
  */
 #define png_ldr(type,pointer)\
    (temp_pointer = png_ptr(type,pointer), *temp_pointer)
@@ -125,12 +133,15 @@ png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row,
       uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp);
       uint8x8x4_t vrp = *vrpt;
       uint32x2x4_t *temp_pointer;
+      uint32x2x4_t vdest_val;
 
       vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
       vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]);
       vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]);
       vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]);
-      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+
+      vdest_val = png_ldr(uint32x2x4_t, &vdest);
+      vst4_lane_u32(png_ptr(uint32_t,rp), vdest_val, 0);
    }
 
    PNG_UNUSED(prev_row)
@@ -223,6 +234,7 @@ png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
       uint8x8x4_t *vrpt, *vppt;
       uint8x8x4_t vrp, vpp;
       uint32x2x4_t *temp_pointer;
+      uint32x2x4_t vdest_val;
 
       vtmp = vld4_u32(png_ptr(uint32_t,rp));
       vrpt = png_ptr(uint8x8x4_t,&vtmp);
@@ -240,7 +252,8 @@ png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
       vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]);
       vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
 
-      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+      vdest_val = png_ldr(uint32x2x4_t, &vdest);
+      vst4_lane_u32(png_ptr(uint32_t,rp), vdest_val, 0);
    }
 }
 
@@ -359,6 +372,7 @@ png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
       uint8x8x4_t *vrpt, *vppt;
       uint8x8x4_t vrp, vpp;
       uint32x2x4_t *temp_pointer;
+      uint32x2x4_t vdest_val;
 
       vtmp = vld4_u32(png_ptr(uint32_t,rp));
       vrpt = png_ptr(uint8x8x4_t,&vtmp);
@@ -378,7 +392,8 @@ png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
 
       vlast = vpp.val[3];
 
-      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+      vdest_val = png_ldr(uint32x2x4_t, &vdest);
+      vst4_lane_u32(png_ptr(uint32_t,rp), vdest_val, 0);
    }
 }
 

arm/palette_neon_intrinsics.c

@@ -0,0 +1,149 @@
+
+/* palette_neon_intrinsics.c - NEON optimised palette expansion functions
+ *
+ * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2017-2018 Arm Holdings. All rights reserved.
+ * Written by Richard Townsend <Richard.Townsend@arm.com>, February 2017.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+#if PNG_ARM_NEON_IMPLEMENTATION == 1
+
+#if defined(_MSC_VER) && defined(_M_ARM64)
+#  include <arm64_neon.h>
+#else
+#  include <arm_neon.h>
+#endif
+
+/* Build an RGBA palette from the RGB and separate alpha palettes. */
+void
+png_riffle_palette_rgba(png_structrp png_ptr, png_row_infop row_info)
+{
+   png_const_colorp palette = png_ptr->palette;
+   png_bytep riffled_palette = png_ptr->riffled_palette;
+   png_const_bytep trans_alpha = png_ptr->trans_alpha;
+   int num_trans = png_ptr->num_trans;
+   int i;
+
+   /* Initially black, opaque. */
+   uint8x16x4_t w = {{
+      vdupq_n_u8(0x00),
+      vdupq_n_u8(0x00),
+      vdupq_n_u8(0x00),
+      vdupq_n_u8(0xff),
+   }};
+
+   if (row_info->bit_depth != 8)
+   {
+      png_error(png_ptr, "bit_depth must be 8 for png_riffle_palette_rgba");
+      return;
+   }
+
+   /* First, riffle the RGB colours into a RGBA palette, the A value is
+    * set to opaque for now.
+    */
+   for (i = 0; i < (1 << row_info->bit_depth); i += 16)
+   {
+      uint8x16x3_t v = vld3q_u8((png_const_bytep)(palette + i));
+      w.val[0] = v.val[0];
+      w.val[1] = v.val[1];
+      w.val[2] = v.val[2];
+      vst4q_u8(riffled_palette + (i << 2), w);
+   }
+
+   /* Fix up the missing transparency values. */
+   for (i = 0; i < num_trans; i++)
+      riffled_palette[(i << 2) + 3] = trans_alpha[i];
+}
+
+/* Expands a palettized row into RGBA. */
+int
+png_do_expand_palette_neon_rgba(png_structrp png_ptr, png_row_infop row_info,
+    png_const_bytep row, png_bytepp ssp, png_bytepp ddp)
+{
+   png_uint_32 row_width = row_info->width;
+   const png_uint_32 *riffled_palette =
+      (const png_uint_32 *)png_ptr->riffled_palette;
+   const png_int_32 pixels_per_chunk = 4;
+   int i;
+
+   if (row_width < pixels_per_chunk)
+      return 0;
+
+   /* This function originally gets the last byte of the output row.
+    * The NEON part writes forward from a given position, so we have
+    * to seek this back by 4 pixels x 4 bytes.
+    */
+   *ddp = *ddp - ((pixels_per_chunk * sizeof(png_uint_32)) - 1);
+
+   for (i = 0; i < row_width; i += pixels_per_chunk)
+   {
+      uint32x4_t cur;
+      png_bytep sp = *ssp - i, dp = *ddp - (i << 2);
+      cur = vld1q_dup_u32 (riffled_palette + *(sp - 3));
+      cur = vld1q_lane_u32(riffled_palette + *(sp - 2), cur, 1);
+      cur = vld1q_lane_u32(riffled_palette + *(sp - 1), cur, 2);
+      cur = vld1q_lane_u32(riffled_palette + *(sp - 0), cur, 3);
+      vst1q_u32((void *)dp, cur);
+   }
+   if (i != row_width)
+   {
+      /* Remove the amount that wasn't processed. */
+      i -= pixels_per_chunk;
+   }
+
+   /* Decrement output pointers. */
+   *ssp = *ssp - i;
+   *ddp = *ddp - (i << 2);
+   return i;
+}
+
+/* Expands a palettized row into RGB format. */
+int
+png_do_expand_palette_neon_rgb(png_structrp png_ptr, png_row_infop row_info,
+    png_const_bytep row, png_bytepp ssp, png_bytepp ddp)
+{
+   png_uint_32 row_width = row_info->width;
+   png_const_bytep palette = (png_const_bytep)png_ptr->palette;
+   const png_uint_32 pixels_per_chunk = 8;
+   int i;
+
+   if (row_width <= pixels_per_chunk)
+      return 0;
+
+   /* Seeking this back by 8 pixels x 3 bytes. */
+   *ddp = *ddp - ((pixels_per_chunk * sizeof(png_color)) - 1);
+
+   for (i = 0; i < row_width; i += pixels_per_chunk)
+   {
+      uint8x8x3_t cur;
+      png_bytep sp = *ssp - i, dp = *ddp - ((i << 1) + i);
+      cur = vld3_dup_u8(palette + sizeof(png_color) * (*(sp - 7)));
+      cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 6)), cur, 1);
+      cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 5)), cur, 2);
+      cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 4)), cur, 3);
+      cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 3)), cur, 4);
+      cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 2)), cur, 5);
+      cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 1)), cur, 6);
+      cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 0)), cur, 7);
+      vst3_u8((void *)dp, cur);
+   }
+
+   if (i != row_width)
+   {
+      /* Remove the amount that wasn't processed. */
+      i -= pixels_per_chunk;
+   }
+
+   /* Decrement output pointers. */
+   *ssp = *ssp - i;
+   *ddp = *ddp - ((i << 1) + i);
+   return i;
+}
+
+#endif /* PNG_ARM_NEON_IMPLEMENTATION */

autogen.sh

@@ -194,7 +194,7 @@ case "$mode" in
       if test -d .git
       then
          exec >&2
-         echo "ERROR: running autoreconf on an initialized sytem"
+         echo "ERROR: running autoreconf on an initialized system"
          echo "  This is not necessary; it is only necessary to remake the"
          echo "  autotools generated files if Makefile.am or configure.ac"
          echo "  change and make does the right thing with:"

compile

@@ -0,0 +1,348 @@
+#! /bin/sh
+# Wrapper for compilers which do not understand '-c -o'.
+
+scriptversion=2018-03-07.03; # UTC
+
+# Copyright (C) 1999-2018 Free Software Foundation, Inc.
+# Written by Tom Tromey <tromey@cygnus.com>.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+# As a special exception to the GNU General Public License, if you
+# distribute this file as part of a program that contains a
+# configuration script generated by Autoconf, you may include it under
+# the same distribution terms that you use for the rest of that program.
+
+# This file is maintained in Automake, please report
+# bugs to <bug-automake@gnu.org> or send patches to
+# <automake-patches@gnu.org>.
+
+nl='
+'
+
+# We need space, tab and new line, in precisely that order.  Quoting is
+# there to prevent tools from complaining about whitespace usage.
+IFS=" ""	$nl"
+
+file_conv=
+
+# func_file_conv build_file lazy
+# Convert a $build file to $host form and store it in $file
+# Currently only supports Windows hosts. If the determined conversion
+# type is listed in (the comma separated) LAZY, no conversion will
+# take place.
+func_file_conv ()
+{
+  file=$1
+  case $file in
+    / | /[!/]*) # absolute file, and not a UNC file
+      if test -z "$file_conv"; then
+	# lazily determine how to convert abs files
+	case `uname -s` in
+	  MINGW*)
+	    file_conv=mingw
+	    ;;
+	  CYGWIN*)
+	    file_conv=cygwin
+	    ;;
+	  *)
+	    file_conv=wine
+	    ;;
+	esac
+      fi
+      case $file_conv/,$2, in
+	*,$file_conv,*)
+	  ;;
+	mingw/*)
+	  file=`cmd //C echo "$file " | sed -e 's/"\(.*\) " *$/\1/'`
+	  ;;
+	cygwin/*)
+	  file=`cygpath -m "$file" || echo "$file"`
+	  ;;
+	wine/*)
+	  file=`winepath -w "$file" || echo "$file"`
+	  ;;
+      esac
+      ;;
+  esac
+}
+
+# func_cl_dashL linkdir
+# Make cl look for libraries in LINKDIR
+func_cl_dashL ()
+{
+  func_file_conv "$1"
+  if test -z "$lib_path"; then
+    lib_path=$file
+  else
+    lib_path="$lib_path;$file"
+  fi
+  linker_opts="$linker_opts -LIBPATH:$file"
+}
+
+# func_cl_dashl library
+# Do a library search-path lookup for cl
+func_cl_dashl ()
+{
+  lib=$1
+  found=no
+  save_IFS=$IFS
+  IFS=';'
+  for dir in $lib_path $LIB
+  do
+    IFS=$save_IFS
+    if $shared && test -f "$dir/$lib.dll.lib"; then
+      found=yes
+      lib=$dir/$lib.dll.lib
+      break
+    fi
+    if test -f "$dir/$lib.lib"; then
+      found=yes
+      lib=$dir/$lib.lib
+      break
+    fi
+    if test -f "$dir/lib$lib.a"; then
+      found=yes
+      lib=$dir/lib$lib.a
+      break
+    fi
+  done
+  IFS=$save_IFS
+
+  if test "$found" != yes; then
+    lib=$lib.lib
+  fi
+}
+
+# func_cl_wrapper cl arg...
+# Adjust compile command to suit cl
+func_cl_wrapper ()
+{
+  # Assume a capable shell
+  lib_path=
+  shared=:
+  linker_opts=
+  for arg
+  do
+    if test -n "$eat"; then
+      eat=
+    else
+      case $1 in
+	-o)
+	  # configure might choose to run compile as 'compile cc -o foo foo.c'.
+	  eat=1
+	  case $2 in
+	    *.o | *.[oO][bB][jJ])
+	      func_file_conv "$2"
+	      set x "$@" -Fo"$file"
+	      shift
+	      ;;
+	    *)
+	      func_file_conv "$2"
+	      set x "$@" -Fe"$file"
+	      shift
+	      ;;
+	  esac
+	  ;;
+	-I)
+	  eat=1
+	  func_file_conv "$2" mingw
+	  set x "$@" -I"$file"
+	  shift
+	  ;;
+	-I*)
+	  func_file_conv "${1#-I}" mingw
+	  set x "$@" -I"$file"
+	  shift
+	  ;;
+	-l)
+	  eat=1
+	  func_cl_dashl "$2"
+	  set x "$@" "$lib"
+	  shift
+	  ;;
+	-l*)
+	  func_cl_dashl "${1#-l}"
+	  set x "$@" "$lib"
+	  shift
+	  ;;
+	-L)
+	  eat=1
+	  func_cl_dashL "$2"
+	  ;;
+	-L*)
+	  func_cl_dashL "${1#-L}"
+	  ;;
+	-static)
+	  shared=false
+	  ;;
+	-Wl,*)
+	  arg=${1#-Wl,}
+	  save_ifs="$IFS"; IFS=','
+	  for flag in $arg; do
+	    IFS="$save_ifs"
+	    linker_opts="$linker_opts $flag"
+	  done
+	  IFS="$save_ifs"
+	  ;;
+	-Xlinker)
+	  eat=1
+	  linker_opts="$linker_opts $2"
+	  ;;
+	-*)
+	  set x "$@" "$1"
+	  shift
+	  ;;
+	*.cc | *.CC | *.cxx | *.CXX | *.[cC]++)
+	  func_file_conv "$1"
+	  set x "$@" -Tp"$file"
+	  shift
+	  ;;
+	*.c | *.cpp | *.CPP | *.lib | *.LIB | *.Lib | *.OBJ | *.obj | *.[oO])
+	  func_file_conv "$1" mingw
+	  set x "$@" "$file"
+	  shift
+	  ;;
+	*)
+	  set x "$@" "$1"
+	  shift
+	  ;;
+      esac
+    fi
+    shift
+  done
+  if test -n "$linker_opts"; then
+    linker_opts="-link$linker_opts"
+  fi
+  exec "$@" $linker_opts
+  exit 1
+}
+
+eat=
+
+case $1 in
+  '')
+     echo "$0: No command.  Try '$0 --help' for more information." 1>&2
+     exit 1;
+     ;;
+  -h | --h*)
+    cat <<\EOF
+Usage: compile [--help] [--version] PROGRAM [ARGS]
+
+Wrapper for compilers which do not understand '-c -o'.
+Remove '-o dest.o' from ARGS, run PROGRAM with the remaining
+arguments, and rename the output as expected.
+
+If you are trying to build a whole package this is not the
+right script to run: please start by reading the file 'INSTALL'.
+
+Report bugs to <bug-automake@gnu.org>.
+EOF
+    exit $?
+    ;;
+  -v | --v*)
+    echo "compile $scriptversion"
+    exit $?
+    ;;
+  cl | *[/\\]cl | cl.exe | *[/\\]cl.exe | \
+  icl | *[/\\]icl | icl.exe | *[/\\]icl.exe )
+    func_cl_wrapper "$@"      # Doesn't return...
+    ;;
+esac
+
+ofile=
+cfile=
+
+for arg
+do
+  if test -n "$eat"; then
+    eat=
+  else
+    case $1 in
+      -o)
+	# configure might choose to run compile as 'compile cc -o foo foo.c'.
+	# So we strip '-o arg' only if arg is an object.
+	eat=1
+	case $2 in
+	  *.o | *.obj)
+	    ofile=$2
+	    ;;
+	  *)
+	    set x "$@" -o "$2"
+	    shift
+	    ;;
+	esac
+	;;
+      *.c)
+	cfile=$1
+	set x "$@" "$1"
+	shift
+	;;
+      *)
+	set x "$@" "$1"
+	shift
+	;;
+    esac
+  fi
+  shift
+done
+
+if test -z "$ofile" || test -z "$cfile"; then
+  # If no '-o' option was seen then we might have been invoked from a
+  # pattern rule where we don't need one.  That is ok -- this is a
+  # normal compilation that the losing compiler can handle.  If no
+  # '.c' file was seen then we are probably linking.  That is also
+  # ok.
+  exec "$@"
+fi
+
+# Name of file we expect compiler to create.
+cofile=`echo "$cfile" | sed 's|^.*[\\/]||; s|^[a-zA-Z]:||; s/\.c$/.o/'`
+
+# Create the lock directory.
+# Note: use '[/\\:.-]' here to ensure that we don't use the same name
+# that we are using for the .o file.  Also, base the name on the expected
+# object file name, since that is what matters with a parallel build.
+lockdir=`echo "$cofile" | sed -e 's|[/\\:.-]|_|g'`.d
+while true; do
+  if mkdir "$lockdir" >/dev/null 2>&1; then
+    break
+  fi
+  sleep 1
+done
+# FIXME: race condition here if user kills between mkdir and trap.
+trap "rmdir '$lockdir'; exit 1" 1 2 15
+
+# Run the compile.
+"$@"
+ret=$?
+
+if test -f "$cofile"; then
+  test "$cofile" = "$ofile" || mv "$cofile" "$ofile"
+elif test -f "${cofile}bj"; then
+  test "${cofile}bj" = "$ofile" || mv "${cofile}bj" "$ofile"
+fi
+
+rmdir "$lockdir"
+exit $ret
+
+# Local Variables:
+# mode: shell-script
+# sh-indentation: 2
+# eval: (add-hook 'before-save-hook 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-time-zone: "UTC0"
+# time-stamp-end: "; # UTC"
+# End:

config.h.in

@@ -0,0 +1,126 @@
+/* config.h.in.  Generated from configure.ac by autoheader.  */
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#undef HAVE_DLFCN_H
+
+/* Define to 1 if you have the `feenableexcept' function. */
+#undef HAVE_FEENABLEEXCEPT
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#undef HAVE_INTTYPES_H
+
+/* Define to 1 if you have the `m' library (-lm). */
+#undef HAVE_LIBM
+
+/* Define to 1 if you have the `z' library (-lz). */
+#undef HAVE_LIBZ
+
+/* Define to 1 if you have the <memory.h> header file. */
+#undef HAVE_MEMORY_H
+
+/* Define to 1 if you have the `pow' function. */
+#undef HAVE_POW
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#undef HAVE_STDINT_H
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#undef HAVE_STDLIB_H
+
+/* Define to 1 if you have the <strings.h> header file. */
+#undef HAVE_STRINGS_H
+
+/* Define to 1 if you have the <string.h> header file. */
+#undef HAVE_STRING_H
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#undef HAVE_SYS_STAT_H
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#undef HAVE_SYS_TYPES_H
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#undef HAVE_UNISTD_H
+
+/* Define to the sub-directory where libtool stores uninstalled libraries. */
+#undef LT_OBJDIR
+
+/* Name of package */
+#undef PACKAGE
+
+/* Define to the address where bug reports for this package should be sent. */
+#undef PACKAGE_BUGREPORT
+
+/* Define to the full name of this package. */
+#undef PACKAGE_NAME
+
+/* Define to the full name and version of this package. */
+#undef PACKAGE_STRING
+
+/* Define to the one symbol short name of this package. */
+#undef PACKAGE_TARNAME
+
+/* Define to the home page for this package. */
+#undef PACKAGE_URL
+
+/* Define to the version of this package. */
+#undef PACKAGE_VERSION
+
+/* Turn on ARM Neon optimizations at run-time */
+#undef PNG_ARM_NEON_API_SUPPORTED
+
+/* Check for ARM Neon support at run-time */
+#undef PNG_ARM_NEON_CHECK_SUPPORTED
+
+/* Enable ARM Neon optimizations */
+#undef PNG_ARM_NEON_OPT
+
+/* Enable Intel SSE optimizations */
+#undef PNG_INTEL_SSE_OPT
+
+/* Turn on MIPS MSA optimizations at run-time */
+#undef PNG_MIPS_MSA_API_SUPPORTED
+
+/* Check for MIPS MSA support at run-time */
+#undef PNG_MIPS_MSA_CHECK_SUPPORTED
+
+/* Enable MIPS MSA optimizations */
+#undef PNG_MIPS_MSA_OPT
+
+/* Turn on POWERPC VSX optimizations at run-time */
+#undef PNG_POWERPC_VSX_API_SUPPORTED
+
+/* Check for POWERPC VSX support at run-time */
+#undef PNG_POWERPC_VSX_CHECK_SUPPORTED
+
+/* Enable POWERPC VSX optimizations */
+#undef PNG_POWERPC_VSX_OPT
+
+/* Define to 1 if you have the ANSI C header files. */
+#undef STDC_HEADERS
+
+/* Define to 1 if your <sys/time.h> declares `struct tm'. */
+#undef TM_IN_SYS_TIME
+
+/* Version number of package */
+#undef VERSION
+
+/* Define to empty if `const' does not conform to ANSI C. */
+#undef const
+
+/* Define to the equivalent of the C99 'restrict' keyword, or to
+   nothing if this is not supported.  Do not define if restrict is
+   supported directly.  */
+#undef restrict
+/* Work around a bug in Sun C++: it does not support _Restrict or
+   __restrict__, even though the corresponding Sun C compiler ends up with
+   "#define restrict _Restrict" or "#define restrict __restrict__" in the
+   previous line.  Perhaps some future version of Sun C++ will work with
+   restrict; if so, hopefully it defines __RESTRICT like Sun C does.  */
+#if defined __SUNPRO_CC && !defined __RESTRICT
+# define _Restrict
+# define __restrict__
+#endif
+
+/* Define to `unsigned int' if <sys/types.h> does not define. */
+#undef size_t

configure.ac

@@ -1,7 +1,7 @@
 # configure.ac
 
+# Copyright (c) 2018 Cosmin Truta
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
-# Last changed in libpng 1.6.25 [October 20, 2016]
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -25,7 +25,7 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.26],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.36],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -46,10 +46,10 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
 
-PNGLIB_VERSION=1.6.26
+PNGLIB_VERSION=1.6.36
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=26
+PNGLIB_RELEASE=36
 
 dnl End of version number stuff
 
@@ -144,7 +144,6 @@ AC_C_RESTRICT
 
 # Checks for library functions.
 AC_FUNC_STRTOD
-AC_CHECK_FUNCS([memset], , AC_MSG_ERROR(memset not found in libc))
 AC_CHECK_FUNCS([pow], , AC_CHECK_LIB(m, pow, , AC_MSG_ERROR(cannot find pow)) )
 
 # Some later POSIX 1003.1 functions are required for test programs, failure here
@@ -300,6 +299,55 @@ AM_CONDITIONAL([DO_INSTALL_LIBPNG_CONFIG],
 # HOST SPECIFIC OPTIONS
 # =====================
 #
+# DEFAULT
+# =======
+#
+AC_ARG_ENABLE([hardware-optimizations],
+   AS_HELP_STRING([[[--enable-hardware-optimizations]]],
+      [Enable hardware optimizations: =no/off, yes/on:]),
+   [case "$enableval" in
+      no|off)
+         # disable hardware optimization on all systems:
+         enable_arm_neon=no
+         AC_DEFINE([PNG_ARM_NEON_OPT], [0],
+           [Disable ARM_NEON optimizations])
+         enable_mips_msa=no
+         AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
+           [Disable MIPS_MSA optimizations])
+         enable_powerpc_vsx=no
+         AC_DEFINE([PNG_POWERPC_VSX_OPT], [0],
+           [Disable POWERPC VSX optimizations])
+         enable_intel_sse=no
+         AC_DEFINE([PNG_INTEL_SSE_OPT], [0],
+           [Disable INTEL_SSE optimizations])
+         ;;
+      *)
+         # allow enabling hardware optimization on any system:
+         case "$host_cpu" in
+            arm*|aarch64*)
+              enable_arm_neon=yes
+              AC_DEFINE([PNG_ARM_NEON_OPT], [0],
+                [Enable ARM_NEON optimizations])
+              ;;
+            mipsel*|mips64el*)
+              enable_mips_msa=yes
+              AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
+                [Enable MIPS_MSA optimizations])
+              ;;
+            i?86|x86_64)
+              enable_intel_sse=yes
+              AC_DEFINE([PNG_INTEL_SSE_OPT], [1],
+                [Enable Intel SSE optimizations])
+              ;;
+            powerpc*|ppc64*)
+              enable_powerpc_vsx=yes
+              AC_DEFINE([PNG_POWERPC_VSX_OPT], [2],
+                [Enable POWERPC VSX optimizations])
+              ;;
+         esac
+         ;;
+   esac])
+
 # ARM
 # ===
 #
@@ -391,6 +439,89 @@ AM_CONDITIONAL([PNG_MIPS_MSA],
       mipsel*|mips64el*) :;;
     esac])
 
+# INTEL
+# =====
+#
+# INTEL SSE (SIMD) support.
+
+AC_ARG_ENABLE([intel-sse],
+   AS_HELP_STRING([[[--enable-intel-sse]]],
+      [Enable Intel SSE optimizations: =no/off, yes/on:]
+      [no/off: disable the optimizations;]
+      [yes/on: enable the optimizations.]
+      [If not specified: determined by the compiler.]),
+   [case "$enableval" in
+      no|off)
+         # disable the default enabling:
+         AC_DEFINE([PNG_INTEL_SSE_OPT], [0],
+                   [Disable Intel SSE optimizations])
+         # Prevent inclusion of the assembler files below:
+         enable_intel_sse=no;;
+      yes|on)
+         AC_DEFINE([PNG_INTEL_SSE_OPT], [1],
+                   [Enable Intel SSE optimizations]);;
+      *)
+         AC_MSG_ERROR([--enable-intel-sse=${enable_intel_sse}: invalid value])
+   esac])
+
+# Add Intel specific files to all builds where the host_cpu is Intel ('x86*')
+# or where Intel optimizations were explicitly requested (this allows a
+# fallback if a future host CPU does not match 'x86*')
+AM_CONDITIONAL([PNG_INTEL_SSE],
+   [test "$enable_intel_sse" != 'no' &&
+    case "$host_cpu" in
+      i?86|x86_64) :;;
+      *)    test "$enable_intel_sse" != '';;
+    esac])
+
+# PowerPC
+# ===
+#
+# PowerPC VSX (SIMD) support.
+
+AC_ARG_ENABLE([powerpc-vsx],
+AS_HELP_STRING([[[--enable-powerpc-vsx]]],
+      [Enable POWERPC VSX optimizations: =no/off, check, api, yes/on:]
+      [no/off: disable the optimizations; check: use internal checking code]
+      [api: disable by default, enable by a call to png_set_option]
+      [yes/on: turn on unconditionally.]
+      [If not specified: determined by the compiler.]),
+   [case "$enableval" in
+      no|off)
+         # disable the default enabling on __ppc64__ systems:
+         AC_DEFINE([PNG_POWERPC_VSX_OPT], [0],
+                   [Disable POWERPC VSX optimizations])
+         # Prevent inclusion of the platform specific files below:
+         enable_powerpc_vsx=no;;
+      check)
+         AC_DEFINE([PNG_POWERPC_VSX_CHECK_SUPPORTED], [],
+                   [Check for POWERPC VSX support at run-time])
+         AC_MSG_WARN([--enable-powerpc-vsx Please check contrib/powerpc/README file]
+            [for the list of supported OSes.]);;
+      api)
+         AC_DEFINE([PNG_POWERPC_VSX_API_SUPPORTED], [],
+                   [Turn on POWERPC VSX optimizations at run-time]);;
+      yes|on)
+         AC_DEFINE([PNG_POWERPC_VSX_OPT], [2],
+                   [Enable POWERPC VSX optimizations])
+         AC_MSG_WARN([--enable-powerpc-vsx: please specify 'check' or 'api', if]
+            [you want the optimizations unconditionally pass '-maltivec -mvsx']
+            [or '-mcpu=power8'to the compiler.]);;
+      *)
+         AC_MSG_ERROR([--enable-powerpc-vsx=${enable_powerpc_vsx}: invalid value])
+   esac])
+
+# Add PowerPC specific files to all builds where the host_cpu is powerpc('powerpc*') or
+# where POWERPC optimizations were explicitly requested (this allows a fallback if a
+# future host CPU does not match 'powerpc*')
+
+AM_CONDITIONAL([PNG_POWERPC_VSX],
+   [test "$enable_powerpc_vsx" != 'no' &&
+    case "$host_cpu" in
+      powerpc*|ppc64*) :;;
+    esac])
+
+
 AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])
 
 # Config files, substituting as above

contrib/arm-neon/android-ndk.c

@@ -17,7 +17,7 @@
  *
  * Documentation:
  *    http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
- *    http://code.google.com/p/android/issues/detail?id=49065
+ *    https://code.google.com/p/android/issues/detail?id=49065
  *
  * NOTE: this requires that libpng is built against the Android NDK and linked
  * with an implementation of the Android ARM 'cpu-features' library.  The code

contrib/arm-neon/linux.c

@@ -1,8 +1,8 @@
 /* contrib/arm-neon/linux.c
  *
- * Copyright (c) 2014 Glenn Randers-Pehrson
- * Written by John Bowler, 2014.
- * Last changed in libpng 1.6.16 [December 22, 2014]
+ * Last changed in libpng 1.6.31 [July 27, 2017]
+ * Copyright (c) 2014, 2017 Glenn Randers-Pehrson
+ * Written by John Bowler, 2014, 2017.
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -62,7 +62,7 @@ png_have_neon(png_structp png_ptr)
 
                counter=0;
                state = Feature;
-               /* FALL THROUGH */
+               /* FALLTHROUGH */
 
             case Feature:
                /* Match 'FEATURE', ASCII case insensitive. */
@@ -75,7 +75,7 @@ png_have_neon(png_structp png_ptr)
 
                /* did not match 'feature' */
                state = SkipLine;
-               /* FALL THROUGH */
+               /* FALLTHROUGH */
 
             case SkipLine:
             skipLine:
@@ -110,7 +110,7 @@ png_have_neon(png_structp png_ptr)
 
                state = Neon;
                counter = 0;
-               /* FALL THROUGH */
+               /* FALLTHROUGH */
 
             case Neon:
                /* Look for 'neon' tag */
@@ -122,7 +122,7 @@ png_have_neon(png_structp png_ptr)
                }
 
                state = SkipTag;
-               /* FALL THROUGH */
+               /* FALLTHROUGH */
 
             case SkipTag:
                /* Skip non-space characters */

contrib/conftest/pngcp.dfa

@@ -33,7 +33,7 @@ option WRITE_16BIT on
 option WRITE_FILTER on
 
 # pngcp needs this to preserve unknown chunks, switching all these on means that
-# pngcp can work without explicit known chunk reading suppport
+# pngcp can work without explicit known chunk reading support
 option UNKNOWN_CHUNKS on
 option SET_UNKNOWN_CHUNKS on
 option HANDLE_AS_UNKNOWN on
@@ -52,6 +52,6 @@ option TEXT on
 option USER_LIMITS on
 option SET_USER_LIMITS on
 
-# these are are just required for specific customizations
+# these are just required for specific customizations
 option WRITE_CUSTOMIZE_ZTXT_COMPRESSION on
 option WRITE_CUSTOMIZE_COMPRESSION on

contrib/examples/iccfrompng.c

@@ -10,7 +10,7 @@
  * without processing the image.  Notice that some header information may occur
  * after the image data. Textual data and comments are an example; the approach
  * in this file won't work reliably for such data because it only looks for the
- * information in the section of the file that preceeds the image data.
+ * information in the section of the file that precedes the image data.
  *
  * Compile and link against libpng and zlib, plus anything else required on the
  * system you use.

contrib/examples/pngpixel.c

@@ -42,7 +42,7 @@ component(png_const_bytep row, png_uint_32 x, unsigned int c,
    png_uint_32 bit_offset_hi = bit_depth * ((x >> 6) * channels);
    png_uint_32 bit_offset_lo = bit_depth * ((x & 0x3f) * channels + c);
 
-   row = (png_const_bytep)(((PNG_CONST png_byte (*)[8])row) + bit_offset_hi);
+   row = (png_const_bytep)(((const png_byte (*)[8])row) + bit_offset_hi);
    row += bit_offset_lo >> 3;
    bit_offset_lo &= 0x07;
 
@@ -73,7 +73,7 @@ static void
 print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
    png_uint_32 x)
 {
-   PNG_CONST unsigned int bit_depth = png_get_bit_depth(png_ptr, info_ptr);
+   unsigned int bit_depth = png_get_bit_depth(png_ptr, info_ptr);
 
    switch (png_get_color_type(png_ptr, info_ptr))
    {
@@ -87,7 +87,7 @@ print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
        */
       case PNG_COLOR_TYPE_PALETTE:
          {
-            PNG_CONST int index = component(row, x, 0, bit_depth, 1);
+            int index = component(row, x, 0, bit_depth, 1);
             png_colorp palette = NULL;
             int num_palette = 0;
 

contrib/examples/pngtopng.c

@@ -1,10 +1,12 @@
 /*- pngtopng
  *
- * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * COPYRIGHT: Written by John Cunningham Bowler, 2011, 2017.
  * To the extent possible under law, the author has waived all copyright and
  * related or neighboring rights to this work.  This work is published from:
  * United States.
  *
+ * Last changed in libpng 1.6.29 [March 16, 2017]
+ *
  * Read a PNG and write it out in a fixed format, using the 'simplified API'
  * that was introduced in libpng-1.6.0.
  *
@@ -59,26 +61,27 @@ int main(int argc, const char **argv)
                else
                   fprintf(stderr, "pngtopng: write %s: %s\n", argv[2],
                       image.message);
-
-               free(buffer);
             }
 
             else
-            {
                fprintf(stderr, "pngtopng: read %s: %s\n", argv[1],
                    image.message);
 
-               /* This is the only place where a 'free' is required; libpng does
-                * the cleanup on error and success, but in this case we couldn't
-                * complete the read because of running out of memory.
-                */
-               png_image_free(&image);
-            }
+            free(buffer);
          }
 
          else
+         {
             fprintf(stderr, "pngtopng: out of memory: %lu bytes\n",
                (unsigned long)PNG_IMAGE_SIZE(image));
+
+            /* This is the only place where a 'free' is required; libpng does
+             * the cleanup on error and success, but in this case we couldn't
+             * complete the read because of running out of memory and so libpng
+             * has not got to the point where it can do cleanup.
+             */
+            png_image_free(&image);
+         }
       }
 
       else

contrib/gregbook/README

@@ -55,7 +55,7 @@ mation and links to the latest version of the source code, and Chapters
 13-15 of the book for detailed discussion of the three programs.
 
 Greg Roelofs
-http://pobox.com/~newt/greg_contact.html
+https://pobox.com/~newt/greg_contact.html
 16 March 2008
 
 
@@ -63,7 +63,7 @@ BUILD INSTRUCTIONS
 
  - Prerequisites (in order of compilation):
 
-      - zlib            http://zlib.net/
+      - zlib            https://zlib.net/
       - libpng          http://www.libpng.org/pub/png/libpng.html
       - pngbook         http://www.libpng.org/pub/png/book/sources.html
 

contrib/gregbook/readpng.c

@@ -4,7 +4,7 @@
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2007,2017 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -264,6 +264,12 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
     *pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr);
     *pChannels = (int)png_get_channels(png_ptr, info_ptr);
 
+    /* Guard against integer overflow */
+    if (height > ((size_t)(-1))/rowbytes) {
+        fprintf(stderr, "readpng:  image_data buffer would be too large\n",
+        return NULL;
+    }
+
     if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
         png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
         return NULL;

contrib/gregbook/readpng2.c

@@ -55,6 +55,7 @@
 
    Changelog:
      2015-11-12 - Check return value of png_get_bKGD() (Glenn R-P)
+     2017-04-22 - Guard against integer overflow (Glenn R-P)
 
   ---------------------------------------------------------------------------*/
 
@@ -145,7 +146,7 @@ int readpng2_init(mainprog_info *mainprog_ptr)
         /* These byte strings were copied from png.h.  If a future version
          * of readpng2.c recognizes more chunks, add them to this list.
          */
-        static PNG_CONST png_byte chunks_to_process[] = {
+        static const png_byte chunks_to_process[] = {
             98,  75,  71,  68, '\0',  /* bKGD */
            103,  65,  77,  65, '\0',  /* gAMA */
            115,  82,  71,  66, '\0',  /* sRGB */

contrib/gregbook/readppm.c

@@ -9,7 +9,7 @@
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2007,2017 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -154,12 +154,17 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
     *pRowbytes = rowbytes = channels*width;
     *pChannels = channels;
 
-    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
+    Trace((stderr, "readpng_get_image:  rowbytes = %ld, height = %ld\n", rowbytes, height));
+
+    /* Guard against integer overflow */
+    if (height > ((size_t)(-1))/rowbytes) {
+        fprintf(stderr, PROGNAME ":  image_data buffer would be too large\n",
         return NULL;
     }
 
-    Trace((stderr, "readpng_get_image:  rowbytes = %ld, height = %ld\n", rowbytes, height));
-
+    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
+        return NULL;
+    }
 
     /* now we can go ahead and just read the whole image */
 

contrib/gregbook/rpng-win.c

@@ -24,10 +24,11 @@
     - 1.10:  enabled "message window"/console (thanks to David Geldreich)
     - 2.00:  dual-licensed (added GNU GPL)
     - 2.01:  fixed improper display of usage screen on PNG error(s)
+    - 2.02:  check for integer overflow (Glenn R-P)
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008, 2017 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -496,6 +497,12 @@ static int rpng_win_create_window(HINSTANCE hInst, int showmode)
 
     wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2;
 
+    /* Guard against integer overflow */
+    if (image_height > ((size_t)(-1))/wimage_rowbytes) {
+        fprintf(stderr, PROGNAME ":  image_data buffer would be too large\n");
+        return 4;   /* fail */
+    }
+
     if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
                               wimage_rowbytes*image_height)))
     {

contrib/gregbook/rpng-x.c

@@ -28,10 +28,11 @@
     - 2.01:  fixed improper display of usage screen on PNG error(s)
     - 2.02:  Added "void(argc);" statement to quiet pedantic compiler warnings
              about unused variable (GR-P)
+    - 2.03:  check for integer overflow (Glenn R-P)
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008, 2017 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors

contrib/gregbook/rpng2-win.c

@@ -33,12 +33,11 @@
     - 2.02:  fixed improper display of usage screen on PNG error(s); fixed
               unexpected-EOF and file-read-error cases
     - 2.03:  removed runtime MMX-enabling/disabling and obsolete -mmx* options
-    - 2.04:
-             (GR-P)
+    - 2.04:  check for integer overflow (Glenn R-P)
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008, 2017 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -650,6 +649,13 @@ static void rpng2_win_init()
     Trace((stderr, "  width  = %ld\n", rpng2_info.width))
     Trace((stderr, "  height = %ld\n", rpng2_info.height))
 
+    /* Guard against integer overflow */
+    if (rpng2_info.height > ((size_t)(-1))/rowbytes) {
+        fprintf(stderr, PROGNAME ":  image_data buffer would be too large\n",
+        readpng2_cleanup(&rpng2_info);
+        return;
+    }
+
     rpng2_info.image_data = (uch *)malloc(rowbytes * rpng2_info.height);
     if (!rpng2_info.image_data) {
         readpng2_cleanup(&rpng2_info);

contrib/gregbook/rpng2-x.c

@@ -44,9 +44,11 @@
     - 2.04:  Added "void(foo);" statements to quiet pedantic compiler warnings
              about unused variables (GR-P)
     - 2.05:  Use nanosleep() instead of usleep(), which is deprecated (GR-P).
+    - 2.06:  check for integer overflow (Glenn R-P)
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2010, 2014-2015 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2010, 2014-2015, 2017 Greg Roelofs.  All rights
+      reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -780,6 +782,13 @@ static void rpng2_x_init(void)
     Trace((stderr, "  width  = %ld\n", rpng2_info.width))
     Trace((stderr, "  height = %ld\n", rpng2_info.height))
 
+    /* Guard against integer overflow */
+    if (rpng2_info.height > ((size_t)(-1))/rpng2_info.rowbytes) {
+        fprintf(stderr, PROGNAME ":  image_data buffer would be too large\n");
+        readpng2_cleanup(&rpng2_info);
+        return;
+    }
+
     rpng2_info.image_data = (uch *)malloc(rowbytes * rpng2_info.height);
     if (!rpng2_info.image_data) {
         readpng2_cleanup(&rpng2_info);

contrib/gregbook/wpng.c

@@ -29,6 +29,7 @@
     - 1.04:  fixed DOS/OS2/Win32 detection, including partial Cygwin fix
               (see http://home.att.net/~perlspinr/diffs/GregBook_cygwin.diff)
     - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  check for integer overflow (Glenn R-P)
 
         [REPORTED BUG (win32 only):  "contrib/gregbook/wpng.c - cmd line
          dose not work!  In order to do something useful I needed to redirect
@@ -38,7 +39,7 @@
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2007, 2017 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -702,7 +703,18 @@ int main(int argc, char **argv)
     if (wpng_info.interlaced) {
         long i;
         ulg bytes;
-        ulg image_bytes = rowbytes * wpng_info.height;   /* overflow? */
+        ulg image_bytes;
+
+        /* Guard against integer overflow */
+        if (wpng_info_height > ((size_t)(-1)/rowbytes ||
+            wpng_info_height > ((ulg)(-1)/rowbytes) {
+            fprintf(stderr, PROGNAME ":  image_data buffer too large\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(5);
+        }
+
+        image_bytes = rowbytes * wpng_info.height;
 
         wpng_info.image_data = (uch *)malloc(image_bytes);
         wpng_info.row_pointers = (uch **)malloc(wpng_info.height*sizeof(uch *));

contrib/gregbook/writepng.c

@@ -4,7 +4,7 @@
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2007, 2017 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors

contrib/intel/INSTALL

@@ -1,158 +0,0 @@
-Enabling SSE support
-
-Copyright (c) 2016 Google, Inc.
-Written by Mike Klein, Matt Sarett
-
-This INSTALL file written by Glenn Randers-Pehrson, 2016.
-
-If you have moved intel_init.c and filter_sse2_intrinsics.c to a different
-directory, be sure to update the '#include "../../pngpriv.h"' line in both
-files if necessary to point to the correct relative location of pngpriv.h
-with respect to the new location of those files.
-
-To enable SSE support in libpng, follow the instructions in I, II, or III,
-below:
-
-I. Using patched "configure" scripts:
-
-First, apply intel_sse.patch in your build directory.
-
-   patch -i contrib/intel/intel_sse.patch -p1
-
-Then, if you are not building in a new GIT clone, e.g., in a tar
-distribution, remove any existing pre-built configure scripts:
-
-   ./configure --enable-maintainer-mode
-   make maintainer-clean
-   ./autogen.sh --maintainer --clean
-
-Finally, configure libpng with -DPNG_INTEL_SSE in CPPFLAGS:
-
-   ./autogen.sh --maintainer
-   CPPFLAGS="-DPNG_INTEL_SSE" ./configure [options]
-   make CPPFLAGS="-DPNG_INTEL_SSE" [options]
-   make
-
-II. Using a custom makefile:
-
-If you are using a custom makefile makefile, you will have to update it
-manually to include contrib/intel/*.o in the dependencies, and to define
-PNG_INTEL_SSE.
-
-III. Using manually updated "configure" scripts:
-
-If you prefer, manually edit pngpriv.h, configure.ac, and Makefile.am,
-following the instructions below, then follow the instructions in
-section II of INSTALL in the main libpng directory, then configure libpng
-with -DPNG_INTEL_SSE in CPPFLAGS.
-
-1. Add the following code to configure.ac under HOST SPECIFIC OPTIONS
-directly beneath the section for ARM:
-
------------------cut----------------
-# INTEL
-# =====
-#
-# INTEL SSE (SIMD) support.
-
-AC_ARG_ENABLE([intel-sse],
-   AS_HELP_STRING([[[--enable-intel-sse]]],
-      [Enable Intel SSE optimizations: =no/off, yes/on:]
-      [no/off: disable the optimizations;]
-      [yes/on: enable the optimizations.]
-      [If not specified: determined by the compiler.]),
-   [case "$enableval" in
-      no|off)
-         # disable the default enabling:
-         AC_DEFINE([PNG_INTEL_SSE_OPT], [0],
-                   [Disable Intel SSE optimizations])
-         # Prevent inclusion of the assembler files below:
-         enable_intel_sse=no;;
-      yes|on)
-         AC_DEFINE([PNG_INTEL_SSE_OPT], [1],
-                   [Enable Intel SSE optimizations]);;
-      *)
-         AC_MSG_ERROR([--enable-intel-sse=${enable_intel_sse}: invalid value])
-   esac])
-
-# Add Intel specific files to all builds where the host_cpu is Intel ('x86*')
-# or where Intel optimizations were explicitly requested (this allows a
-# fallback if a future host CPU does not match 'x86*')
-AM_CONDITIONAL([PNG_INTEL_SSE],
-   [test "$enable_intel_sse" != 'no' &&
-    case "$host_cpu" in
-      i?86|x86_64) :;;
-      *)    test "$enable_intel_sse" != '';;
-    esac])
------------------cut----------------
-
-2. Add the following code to Makefile.am under HOST SPECIFIC OPTIONS
-directly beneath the "if PNG_ARM_NEON ... endif" statement:
-
------------------cut----------------
-if PNG_INTEL_SSE
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += contrib/intel/intel_init.c\
-    contrib/intel/filter_sse2_intrinsics.c
-endif
------------------cut----------------
-
-3. Add the following lines to pngpriv.h, following the PNG_ARM_NEON_OPT
-code:
-
------------------cut----------------
-#ifndef PNG_INTEL_SSE_OPT
-#   ifdef PNG_INTEL_SSE
-      /* Only check for SSE if the build configuration has been modified to
-       * enable SSE optimizations.  This means that these optimizations will
-       * be off by default.  See contrib/intel for more details.
-       */
-#     if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
-       defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
-       (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
-#         define PNG_INTEL_SSE_OPT 1
-#      endif
-#   endif
-#endif
-
-#if PNG_INTEL_SSE_OPT > 0
-#   ifndef PNG_INTEL_SSE_IMPLEMENTATION
-#      if defined(__SSE4_1__) || defined(__AVX__)
-          /* We are not actually using AVX, but checking for AVX is the best
-             way we can detect SSE4.1 and SSSE3 on MSVC.
-          */
-#         define PNG_INTEL_SSE_IMPLEMENTATION 3
-#      elif defined(__SSSE3__)
-#         define PNG_INTEL_SSE_IMPLEMENTATION 2
-#      elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
-       (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
-#         define PNG_INTEL_SSE_IMPLEMENTATION 1
-#      else
-#         define PNG_INTEL_SSE_IMPLEMENTATION 0
-#      endif
-#   endif
-
-#   if PNG_INTEL_SSE_IMPLEMENTATION > 0
-#      define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
-#   endif
-#endif
-
------------------cut----------------
-
-4. Add the following lines to pngpriv.h, following the prototype for
-png_read_filter_row_paeth4_neon:
-
------------------cut----------------
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
-    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
-    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
-    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
-    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
-    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
-    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-
------------------cut----------------

contrib/intel/intel_sse.patch

@@ -1,190 +0,0 @@
-diff --git a/configure.ac b/configure.ac
---- a/configure.ac	2016-08-29 11:46:27.000000000 -0400
-+++ b/configure.ac	2016-08-29 16:57:03.866355018 -0400
-@@ -386,16 +386,51 @@ AC_ARG_ENABLE([mips-msa],
- # future host CPU does not match 'mips*')
- 
- AM_CONDITIONAL([PNG_MIPS_MSA],
-    [test "$enable_mips_msa" != 'no' &&
-     case "$host_cpu" in
-       mipsel*|mips64el*) :;;
-     esac])
- 
-+# INTEL
-+# =====
-+#
-+# INTEL SSE (SIMD) support.
-+
-+AC_ARG_ENABLE([intel-sse],
-+   AS_HELP_STRING([[[--enable-intel-sse]]],
-+      [Enable Intel SSE optimizations: =no/off, yes/on:]
-+      [no/off: disable the optimizations;]
-+      [yes/on: enable the optimizations.]
-+      [If not specified: determined by the compiler.]),
-+   [case "$enableval" in
-+      no|off)
-+         # disable the default enabling:
-+         AC_DEFINE([PNG_INTEL_SSE_OPT], [0],
-+                   [Disable Intel SSE optimizations])
-+         # Prevent inclusion of the assembler files below:
-+         enable_intel_sse=no;;
-+      yes|on)
-+         AC_DEFINE([PNG_INTEL_SSE_OPT], [1],
-+                   [Enable Intel SSE optimizations]);;
-+      *)
-+         AC_MSG_ERROR([--enable-intel-sse=${enable_intel_sse}: invalid value])
-+   esac])
-+
-+# Add Intel specific files to all builds where the host_cpu is Intel ('x86*')
-+# or where Intel optimizations were explicitly requested (this allows a
-+# fallback if a future host CPU does not match 'x86*')
-+AM_CONDITIONAL([PNG_INTEL_SSE],
-+   [test "$enable_intel_sse" != 'no' &&
-+    case "$host_cpu" in
-+      i?86|x86_64) :;;
-+      *)    test "$enable_intel_sse" != '';;
-+    esac])
-+
- AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])
- 
- # Config files, substituting as above
- AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in])
- AC_CONFIG_FILES([libpng-config:libpng-config.in],
-    [chmod +x libpng-config])
- 
- AC_OUTPUT
-diff --git a/Makefile.am b/Makefile.am
---- a/Makefile.am	2016-08-29 11:46:27.000000000 -0400
-+++ b/Makefile.am	2016-08-29 16:57:45.955528215 -0400
-@@ -97,16 +97,21 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SO
- 	arm/filter_neon.S arm/filter_neon_intrinsics.c
- endif
- 
- if PNG_MIPS_MSA
- libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/mips_init.c\
- 	mips/filter_msa_intrinsics.c
- endif
- 
-+if PNG_INTEL_SSE
-+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += contrib/intel/intel_init.c\
-+    contrib/intel/filter_sse2_intrinsics.c
-+endif
-+
- nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
- 
- libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined -export-dynamic \
- 	-version-number @PNGLIB_MAJOR@@PNGLIB_MINOR@:@PNGLIB_RELEASE@:0
- 
- if HAVE_LD_VERSION_SCRIPT
- #   Versioned symbols and restricted exports
- if HAVE_SOLARIS_LD
-diff --git a/pngpriv.h b/pngpriv.h
---- debug16/pngpriv.h	2016-08-30 10:46:36.000000000 -0400
-+++ libpng16/pngpriv.h	2016-08-30 11:57:25.672280202 -0400
-@@ -185,16 +185,52 @@
- #ifndef PNG_MIPS_MSA_OPT
- #  if defined(__mips_msa) && (__mips_isa_rev >= 5) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
- #     define PNG_MIPS_MSA_OPT 2
- #  else
- #     define PNG_MIPS_MSA_OPT 0
- #  endif
- #endif
- 
-+#ifndef PNG_INTEL_SSE_OPT
-+#   ifdef PNG_INTEL_SSE
-+      /* Only check for SSE if the build configuration has been modified to
-+       * enable SSE optimizations.  This means that these optimizations will
-+       * be off by default.  See contrib/intel for more details.
-+       */
-+#     if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
-+       defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
-+       (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
-+#         define PNG_INTEL_SSE_OPT 1
-+#      endif
-+#   endif
-+#endif
-+
-+#if PNG_INTEL_SSE_OPT > 0
-+#   ifndef PNG_INTEL_SSE_IMPLEMENTATION
-+#      if defined(__SSE4_1__) || defined(__AVX__)
-+          /* We are not actually using AVX, but checking for AVX is the best
-+             way we can detect SSE4.1 and SSSE3 on MSVC.
-+          */
-+#         define PNG_INTEL_SSE_IMPLEMENTATION 3
-+#      elif defined(__SSSE3__)
-+#         define PNG_INTEL_SSE_IMPLEMENTATION 2
-+#      elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
-+       (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
-+#         define PNG_INTEL_SSE_IMPLEMENTATION 1
-+#      else
-+#         define PNG_INTEL_SSE_IMPLEMENTATION 0
-+#      endif
-+#   endif
-+
-+#   if PNG_INTEL_SSE_IMPLEMENTATION > 0
-+#      define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
-+#   endif
-+#endif
-+
- #if PNG_MIPS_MSA_OPT > 0
- #  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_msa
- #  ifndef PNG_MIPS_MSA_IMPLEMENTATION
- #     if defined(__mips_msa)
- #        if defined(__clang__)
- #        elif defined(__GNUC__)
- #           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
- #              define PNG_MIPS_MSA_IMPLEMENTATION 2
-@@ -1251,16 +1287,31 @@ PNG_INTERNAL_FUNCTION(void,png_read_filt
- PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop
-     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
- PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop
-     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
- PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop
-     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
- #endif
- 
-+#if PNG_INTEL_SSE_IMPLEMENTATION > 0
-+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
-+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
-+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
-+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
-+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
-+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
-+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-+#endif
-+
- /* Choose the best filter to use and filter the row data */
- PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
-     png_row_infop row_info),PNG_EMPTY);
- 
- #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
- PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
-    png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
-    /* Read 'avail_out' bytes of data from the IDAT stream.  If the output buffer
-@@ -1986,16 +2037,21 @@ PNG_INTERNAL_FUNCTION(void, PNG_FILTER_O
- PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
-    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
- #endif
- 
- #if PNG_MIPS_MSA_OPT > 0
- PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_msa,
-    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
- #endif
-+
-+#  if PNG_INTEL_SSE_IMPLEMENTATION > 0
-+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
-+   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
-+#  endif
- #endif
- 
- PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
-    png_const_charp key, png_bytep new_key), PNG_EMPTY);
- 
- /* Maintainer: Put new private prototypes here ^ */
- 
- #include "pngdebug.h"

contrib/libtests/makepng.c

@@ -661,7 +661,7 @@ generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
       {
          case 1:
             {
-               const png_uint_32 luma = colors[1];
+               png_uint_32 luma = colors[1];
                png_uint_32 x;
 
                for (x=0; x<=size_max; ++x)
@@ -672,8 +672,8 @@ generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
 
          case 2:
             {
-               const png_uint_32 luma = colors[1];
-               const png_uint_32 alpha = colors[2];
+               png_uint_32 luma = colors[1];
+               png_uint_32 alpha = colors[2];
                png_uint_32 x;
 
                for (x=0; x<size_max; ++x)
@@ -688,9 +688,9 @@ generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
 
          case 3:
             {
-               const png_uint_32 red = colors[1];
-               const png_uint_32 green = colors[2];
-               const png_uint_32 blue = colors[3];
+               png_uint_32 red = colors[1];
+               png_uint_32 green = colors[2];
+               png_uint_32 blue = colors[3];
                png_uint_32 x;
 
                for (x=0; x<=size_max; ++x)
@@ -707,10 +707,10 @@ generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
 
          case 4:
             {
-               const png_uint_32 red = colors[1];
-               const png_uint_32 green = colors[2];
-               const png_uint_32 blue = colors[3];
-               const png_uint_32 alpha = colors[4];
+               png_uint_32 red = colors[1];
+               png_uint_32 green = colors[2];
+               png_uint_32 blue = colors[3];
+               png_uint_32 alpha = colors[4];
                png_uint_32 x;
 
                for (x=0; x<=size_max; ++x)
@@ -812,7 +812,7 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,
       png_error(png_ptr, "OOM allocating info structure");
 
    {
-      const unsigned int size =
+      unsigned int size =
          image_size_of_type(color_type, bit_depth, colors, small);
       unsigned int ysize;
       png_fixed_point real_gamma = 45455; /* For sRGB */
@@ -824,7 +824,7 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,
        */
       if (small)
       {
-         const unsigned int pixel_depth =
+         unsigned int pixel_depth =
             pixel_depth_of_type(color_type, bit_depth);
 
          if (pixel_depth <= 8U)
@@ -950,7 +950,7 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,
             int passes = 1;
 #        endif /* !WRITE_INTERLACING */
          int pass;
-         png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+         size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
 
          row = malloc(rowbytes);
 
@@ -1094,7 +1094,7 @@ load_file(png_const_charp name, png_bytepp result)
    return 0;
 }
 
-static png_size_t
+static size_t
 load_fake(png_charp param, png_bytepp profile)
 {
    char *endptr = NULL;
@@ -1164,7 +1164,7 @@ insert_iCCP(png_structp png_ptr, png_infop info_ptr, int nparams,
    {
       case '<':
          {
-            png_size_t filelen = load_file(params[1]+1, &profile);
+            size_t filelen = load_file(params[1]+1, &profile);
             if (filelen > 0xfffffffc) /* Maximum profile length */
             {
                fprintf(stderr, "%s: file too long (%lu) for an ICC profile\n",
@@ -1179,7 +1179,7 @@ insert_iCCP(png_structp png_ptr, png_infop info_ptr, int nparams,
       case '0': case '1': case '2': case '3': case '4':
       case '5': case '6': case '7': case '8': case '9':
          {
-            png_size_t fake_len = load_fake(params[1], &profile);
+            size_t fake_len = load_fake(params[1], &profile);
 
             if (fake_len > 0) /* else a simple parameter */
             {
@@ -1274,7 +1274,7 @@ set_text(png_structp png_ptr, png_infop info_ptr, png_textp text,
       case '5': case '6': case '7': case '8': case '9':
          {
             png_bytep data = NULL;
-            png_size_t fake_len = load_fake(param, &data);
+            size_t fake_len = load_fake(param, &data);
 
             if (fake_len > 0) /* else a simple parameter */
             {
@@ -1378,10 +1378,10 @@ static void
 insert_sBIT(png_structp png_ptr, png_infop info_ptr, int nparams,
       png_charpp params)
 {
-   const int ct = png_get_color_type(png_ptr, info_ptr);
-   const int c = (ct & PNG_COLOR_MASK_COLOR ? 3 : 1) +
+   int ct = png_get_color_type(png_ptr, info_ptr);
+   int c = (ct & PNG_COLOR_MASK_COLOR ? 3 : 1) +
       (ct & PNG_COLOR_MASK_ALPHA ? 1 : 0);
-   const unsigned int maxval =
+   unsigned int maxval =
       ct & PNG_COLOR_MASK_PALETTE ? 8U : png_get_bit_depth(png_ptr, info_ptr);
    png_color_8 sBIT;
 
@@ -1856,7 +1856,7 @@ main(int argc, char **argv)
 
    /* Check the colors */
    {
-      const unsigned int lim = (color_type == PNG_COLOR_TYPE_PALETTE ? 255U :
+      unsigned int lim = (color_type == PNG_COLOR_TYPE_PALETTE ? 255U :
          (1U<<bit_depth)-1);
       unsigned int i;
 

contrib/libtests/pngimage.c

@@ -551,7 +551,7 @@ struct display
    png_structp    original_pp;       /* used on the original read */
    png_infop      original_ip;       /* set by the original read */
 
-   png_size_t     original_rowbytes; /* of the original rows: */
+   size_t         original_rowbytes; /* of the original rows: */
    png_bytepp     original_rows;     /* from the original read */
 
    /* Original chunks valid */
@@ -807,7 +807,7 @@ display_cache_file(struct display *dp, const char *filename)
 
 static void
 buffer_read(struct display *dp, struct buffer *bp, png_bytep data,
-   png_size_t size)
+   size_t size)
 {
    struct buffer_list *last = bp->current;
    size_t read_count = bp->read_count;
@@ -855,7 +855,7 @@ buffer_read(struct display *dp, struct buffer *bp, png_bytep data,
 }
 
 static void PNGCBAPI
-read_function(png_structp pp, png_bytep data, png_size_t size)
+read_function(png_structp pp, png_bytep data, size_t size)
 {
    buffer_read(get_dp(pp), get_buffer(pp), data, size);
 }
@@ -927,7 +927,7 @@ update_display(struct display *dp)
    png_structp pp;
    png_infop   ip;
 
-   /* Now perform the initial read with a 0 tranform. */
+   /* Now perform the initial read with a 0 transform. */
    read_png(dp, &dp->original_file, "original read", 0/*no transform*/);
 
    /* Move the result to the 'original' fields */
@@ -1267,7 +1267,7 @@ compare_read(struct display *dp, int applied_transforms)
 #ifdef PNG_WRITE_PNG_SUPPORTED
 static void
 buffer_write(struct display *dp, struct buffer *buffer, png_bytep data,
-   png_size_t size)
+   size_t size)
    /* Generic write function used both from the write callback provided to
     * libpng and from the generic read code.
     */
@@ -1311,7 +1311,7 @@ buffer_write(struct display *dp, struct buffer *buffer, png_bytep data,
 }
 
 static void PNGCBAPI
-write_function(png_structp pp, png_bytep data, png_size_t size)
+write_function(png_structp pp, png_bytep data, size_t size)
 {
    buffer_write(get_dp(pp), get_buffer(pp), data, size);
 }
@@ -1446,7 +1446,7 @@ test_one_file(struct display *dp, const char *filename)
        * unsigned, because some transforms are negative on a 16-bit system.
        */
       unsigned int active = dp->active_transforms;
-      const int exhaustive = (dp->options & EXHAUSTIVE) != 0;
+      int exhaustive = (dp->options & EXHAUSTIVE) != 0;
       unsigned int current = first_transform(active);
       unsigned int bad_transforms = 0;
       unsigned int bad_combo = ~0U;    /* bitwise AND of failing transforms */
@@ -1572,7 +1572,7 @@ do_test(struct display *dp, const char *file)
 }
 
 int
-main(const int argc, const char * const * const argv)
+main(int argc, char **argv)
 {
    /* For each file on the command line test it with a range of transforms */
    int option_end, ilog = 0;
@@ -1674,7 +1674,7 @@ main(const int argc, const char * const * const argv)
          /* Here on any return, including failures, except user/internal issues
           */
          {
-            const int pass = (d.options & STRICT) ?
+            int pass = (d.options & STRICT) ?
                RESULT_STRICT(d.results) : RESULT_RELAXED(d.results);
 
             if (!pass)

contrib/libtests/pngstest.c

@@ -1,9 +1,8 @@
 /*-
  * pngstest.c
  *
- * Copyright (c) 2013-2016 John Cunningham Bowler
- *
- * Last changed in libpng 1.6.24 [August 4, 2016]
+ * Last changed in libpng 1.6.31 [July 27, 2017]
+ * Copyright (c) 2013-2017 John Cunningham Bowler
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -373,7 +372,7 @@ print_opts(png_uint_32 opts)
  */
 #define FORMAT_COUNT 64
 #define FORMAT_MASK 0x3f
-static PNG_CONST char * PNG_CONST format_names[FORMAT_COUNT] =
+static const char * const format_names[FORMAT_COUNT] =
 {
    "sRGB-gray",
    "sRGB-gray+alpha",
@@ -579,11 +578,11 @@ typedef struct
    int         stride_extra;
    FILE       *input_file;
    png_voidp   input_memory;
-   png_size_t  input_memory_size;
+   size_t      input_memory_size;
    png_bytep   buffer;
    ptrdiff_t   stride;
-   png_size_t  bufsize;
-   png_size_t  allocsize;
+   size_t      bufsize;
+   size_t      allocsize;
    char        tmpfile_name[32];
    png_uint_16 colormap[256*4];
 }
@@ -666,7 +665,7 @@ static void initimage(Image *image, png_uint_32 opts, const char *file_name,
 static void
 allocbuffer(Image *image)
 {
-   png_size_t size = PNG_IMAGE_BUFFER_SIZE(image->image, image->stride);
+   size_t size = PNG_IMAGE_BUFFER_SIZE(image->image, image->stride);
 
    if (size+32 > image->bufsize)
    {
@@ -1143,7 +1142,7 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
    }
 }
 
-/* Convertion between pixel formats.  The code above effectively eliminates the
+/* Conversion between pixel formats.  The code above effectively eliminates the
  * component ordering changes leaving three basic changes:
  *
  * 1) Remove an alpha channel by pre-multiplication or compositing on a
@@ -2037,7 +2036,7 @@ typedef struct
    /* Precalculated values: */
    int          in_opaque;   /* Value of input alpha that is opaque */
    int          is_palette;  /* Sample values come from the palette */
-   int          accumulate;  /* Accumlate component errors (don't log) */
+   int          accumulate;  /* Accumulate component errors (don't log) */
    int          output_8bit; /* Output is 8-bit (else 16-bit) */
 
    void (*in_gp)(Pixel*, png_const_voidp);
@@ -2347,8 +2346,8 @@ static int
 logpixel(const Transform *transform, png_uint_32 x, png_uint_32 y,
    const Pixel *in, const Pixel *calc, const Pixel *out, const char *reason)
 {
-   const png_uint_32 in_format = transform->in_image->image.format;
-   const png_uint_32 out_format = transform->out_image->image.format;
+   png_uint_32 in_format = transform->in_image->image.format;
+   png_uint_32 out_format = transform->out_image->image.format;
 
    png_uint_32 back_format = out_format & ~PNG_FORMAT_FLAG_ALPHA;
    const char *via_linear = "";
@@ -2603,17 +2602,17 @@ compare_two_images(Image *a, Image *b, int via_linear,
    ptrdiff_t strideb = b->stride;
    png_const_bytep rowa = a->buffer+16;
    png_const_bytep rowb = b->buffer+16;
-   const png_uint_32 width = a->image.width;
-   const png_uint_32 height = a->image.height;
-   const png_uint_32 formata = a->image.format;
-   const png_uint_32 formatb = b->image.format;
-   const unsigned int a_sample = PNG_IMAGE_SAMPLE_SIZE(formata);
-   const unsigned int b_sample = PNG_IMAGE_SAMPLE_SIZE(formatb);
+   png_uint_32 width = a->image.width;
+   png_uint_32 height = a->image.height;
+   png_uint_32 formata = a->image.format;
+   png_uint_32 formatb = b->image.format;
+   unsigned int a_sample = PNG_IMAGE_SAMPLE_SIZE(formata);
+   unsigned int b_sample = PNG_IMAGE_SAMPLE_SIZE(formatb);
    int alpha_added, alpha_removed;
    int bchannels;
-   int btoa[4];
    png_uint_32 y;
    Transform tr;
+   int btoa[4]={0,0,0,0};
 
    /* This should never happen: */
    if (width != b->image.width || height != b->image.height)
@@ -2727,7 +2726,7 @@ compare_two_images(Image *a, Image *b, int via_linear,
                result = 0;
          }
 
-         /* If reqested copy the error values back from the Transform. */
+         /* If requested, copy the error values back from the Transform. */
          if (a->opts & ACCUMULATE)
          {
             tr.error_ptr[0] = tr.error[0];
@@ -2746,22 +2745,27 @@ compare_two_images(Image *a, Image *b, int via_linear,
        */
       else if ((a->opts & ACCUMULATE) == 0)
       {
+#        ifdef __GNUC__
+#           define BYTE_CHARS 20 /* 2^32: GCC sprintf warning */
+#        else
+#           define BYTE_CHARS 3 /* 2^8: real maximum value */
+#        endif
          /* Check the original image first,
           * TODO: deal with input images with bad pixel values?
           */
          if (amax >= a->image.colormap_entries)
          {
-            char pindex[9];
-            sprintf(pindex, "%d[%lu]", amax,
-               (unsigned long)a->image.colormap_entries);
+            char pindex[3+2*BYTE_CHARS];
+            sprintf(pindex, "%d[%u]", amax,
+               (png_byte)/*SAFE*/a->image.colormap_entries);
             return logerror(a, a->file_name, ": bad pixel index: ", pindex);
          }
 
          else if (bmax >= b->image.colormap_entries)
          {
-            char pindex[9];
-            sprintf(pindex, "%d[%lu]", bmax,
-               (unsigned long)b->image.colormap_entries);
+            char pindex[3+2*BYTE_CHARS];
+            sprintf(pindex, "%d[%u]", bmax,
+               (png_byte)/*SAFE*/b->image.colormap_entries);
             return logerror(b, b->file_name, ": bad pixel index: ", pindex);
          }
       }
@@ -2786,8 +2790,7 @@ compare_two_images(Image *a, Image *b, int via_linear,
       (formata & (formatb ^ PNG_FORMAT_FLAG_COLOR) & PNG_FORMAT_FLAG_COLOR)))
    {
       /* Was an alpha channel changed? */
-      const png_uint_32 alpha_changed = (formata ^ formatb) &
-         PNG_FORMAT_FLAG_ALPHA;
+      png_uint_32 alpha_changed = (formata ^ formatb) & PNG_FORMAT_FLAG_ALPHA;
 
       /* Was an alpha channel removed?  (The third test.)  If so the direct
        * comparison is only possible if the input alpha is opaque.
@@ -2881,10 +2884,13 @@ compare_two_images(Image *a, Image *b, int via_linear,
                {
                   case 4:
                      if (pua[btoa[3]] != pub[3]) break;
+                     /* FALLTHROUGH */
                   case 3:
                      if (pua[btoa[2]] != pub[2]) break;
+                     /* FALLTHROUGH */
                   case 2:
                      if (pua[btoa[1]] != pub[1]) break;
+                     /* FALLTHROUGH */
                   case 1:
                      if (pua[btoa[0]] != pub[0]) break;
                      if (alpha_added != 4 && pub[alpha_added] != 65535) break;
@@ -2900,10 +2906,13 @@ compare_two_images(Image *a, Image *b, int via_linear,
                {
                   case 4:
                      if (psa[btoa[3]] != psb[3]) break;
+                     /* FALLTHROUGH */
                   case 3:
                      if (psa[btoa[2]] != psb[2]) break;
+                     /* FALLTHROUGH */
                   case 2:
                      if (psa[btoa[1]] != psb[1]) break;
+                     /* FALLTHROUGH */
                   case 1:
                      if (psa[btoa[0]] != psb[0]) break;
                      if (alpha_added != 4 && psb[alpha_added] != 255) break;
@@ -2922,7 +2931,7 @@ compare_two_images(Image *a, Image *b, int via_linear,
       }
    }
 
-   /* If reqested copy the error values back from the Transform. */
+   /* If requested, copy the error values back from the Transform. */
    if (a->opts & ACCUMULATE)
    {
       tr.error_ptr[0] = tr.error[0];
@@ -3617,7 +3626,7 @@ main(int argc, char **argv)
 
          if (arg[0] == '-')
          {
-            const int term = (arg[1] == '0' ? 0 : '\n');
+            int term = (arg[1] == '0' ? 0 : '\n');
             unsigned int ich = 0;
 
             /* Loop reading files, use a static buffer to simplify this and just

contrib/libtests/pngunknown.c

@@ -1,8 +1,8 @@
 
 /* pngunknown.c - test the read side unknown chunk handling
  *
- * Last changed in libpng 1.6.26 [October 20, 2016]
- * Copyright (c) 2015,2016 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 2015,2017 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
  * This code is released under the libpng license.
@@ -56,7 +56,7 @@
    defined(PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED)
 
 #if PNG_LIBPNG_VER < 10500
-/* This deliberately lacks the PNG_CONST. */
+/* This deliberately lacks the const. */
 typedef png_byte *png_const_bytep;
 
 /* This is copied from 1.5.1 png.h: */
@@ -85,7 +85,7 @@ typedef png_byte *png_const_bytep;
 #define PNG_WRITE_16BIT_SUPPORTED
 #define PNG_READ_16BIT_SUPPORTED
 
-/* This comes from pnglibconf.h afer 1.5: */
+/* This comes from pnglibconf.h after 1.5: */
 #define PNG_FP_1 100000
 #define PNG_GAMMA_THRESHOLD_FIXED\
    ((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1))
@@ -114,6 +114,7 @@ typedef png_byte *png_const_bytep;
 #define png_PLTE PNG_U32( 80,  76,  84,  69)
 #define png_bKGD PNG_U32( 98,  75,  71,  68)
 #define png_cHRM PNG_U32( 99,  72,  82,  77)
+#define png_eXIf PNG_U32(101,  88,  73, 102) /* registered July 2017 */
 #define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
 #define png_gAMA PNG_U32(103,  65,  77,  65)
 #define png_gIFg PNG_U32(103,  73,  70, 103)
@@ -210,6 +211,13 @@ static struct
          1,
 #     endif
       1,  START, 0 },
+   { "eXIf", PNG_INFO_eXIf, png_eXIf,
+#     ifdef PNG_READ_eXIf_SUPPORTED
+         0,
+#     else
+         1,
+#     endif
+      1,  END, 0 },
    { "gAMA", PNG_INFO_gAMA, png_gAMA,
 #     ifdef PNG_READ_gAMA_SUPPORTED
          0,
@@ -614,7 +622,7 @@ get_unknown(display *d, png_infop info_ptr, int after_IDAT)
                   ++(d->error_count);
                   break;
                }
-               /* FALL THROUGH (safe) */
+               /* FALLTHROUGH */ /* (safe) */
             case PNG_HANDLE_CHUNK_ALWAYS:
                break;
          }
@@ -1090,7 +1098,7 @@ static const char *standard_tests[] =
  "sTER", "sTER=if-safe", 0,
  "IDAT", "default=discard", "IDAT=save", 0,
  "sAPI", "bKGD=save", "cHRM=save", "gAMA=save", "all=discard", "iCCP=save",
-   "sBIT=save", "sRGB=save", 0,
+   "sBIT=save", "sRGB=save", "eXIf=save", 0,
  0/*end*/
 };
 

contrib/libtests/pngvalid.c

@@ -1,8 +1,8 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.26 [October 20, 2016]
- * Copyright (c) 2014-2016 John Cunningham Bowler
+ * Last changed in libpng 1.6.31 [July 27, 2017]
+ * Copyright (c) 2014-2017 John Cunningham Bowler
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -21,6 +21,7 @@
 #define _POSIX_SOURCE 1
 #define _ISOC99_SOURCE 1 /* For floating point */
 #define _GNU_SOURCE 1 /* For the floating point exception extension */
+#define _BSD_SOURCE 1 /* For the floating point exception extension */
 
 #include <signal.h>
 #include <stdio.h>
@@ -102,7 +103,7 @@ typedef png_byte *png_const_bytep;
 #define PNG_WRITE_16BIT_SUPPORTED
 #define PNG_READ_16BIT_SUPPORTED
 
-/* This comes from pnglibconf.h afer 1.5: */
+/* This comes from pnglibconf.h after 1.5: */
 #define PNG_FP_1 100000
 #define PNG_GAMMA_THRESHOLD_FIXED\
    ((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1))
@@ -711,7 +712,7 @@ typedef struct png_store_file
    unsigned int            IDAT_bits; /* Number of bits in IDAT size */
    png_uint_32             IDAT_size; /* Total size of IDAT data */
    png_uint_32             id;        /* must be correct (see FILEID) */
-   png_size_t              datacount; /* In this (the last) buffer */
+   size_t                  datacount; /* In this (the last) buffer */
    png_store_buffer        data;      /* Last buffer in file */
    int                     npalette;  /* Number of entries in palette */
    store_palette_entry*    palette;   /* May be NULL */
@@ -777,10 +778,10 @@ typedef struct png_store
    png_infop          piread;
    png_store_file*    current;  /* Set when reading */
    png_store_buffer*  next;     /* Set when reading */
-   png_size_t         readpos;  /* Position in *next */
+   size_t             readpos;  /* Position in *next */
    png_byte*          image;    /* Buffer for reading interlaced images */
-   png_size_t         cb_image; /* Size of this buffer */
-   png_size_t         cb_row;   /* Row size of the image(s) */
+   size_t             cb_image; /* Size of this buffer */
+   size_t             cb_row;   /* Row size of the image(s) */
    uLong              IDAT_crc;
    png_uint_32        IDAT_len; /* Used when re-chunking IDAT chunks */
    png_uint_32        IDAT_pos; /* Used when re-chunking IDAT chunks */
@@ -791,7 +792,7 @@ typedef struct png_store
    png_store_file*    saved;
    png_structp        pwrite;   /* Used when writing a new file */
    png_infop          piwrite;
-   png_size_t         writepos; /* Position in .new */
+   size_t             writepos; /* Position in .new */
    char               wname[FILE_NAME_SIZE];
    png_store_buffer   new;      /* The end of the new PNG file being written. */
    store_pool         write_memory_pool;
@@ -961,7 +962,7 @@ bits_of(png_uint_32 num)
    return b; /* 0..32 */
 }
 
-/* Main interface to file storeage, after writing a new PNG file (see the API
+/* Main interface to file storage, after writing a new PNG file (see the API
  * below) call store_storefile to store the result with the given name and id.
  */
 static void
@@ -1125,7 +1126,7 @@ static png_bytep
 store_image_row(const png_store* ps, png_const_structp pp, int nImage,
    png_uint_32 y)
 {
-   png_size_t coffset = (nImage * ps->image_h + y) * (ps->cb_row + 5) + 2;
+   size_t coffset = (nImage * ps->image_h + y) * (ps->cb_row + 5) + 2;
 
    if (ps->image == NULL)
       png_error(pp, "no allocated image");
@@ -1160,9 +1161,9 @@ store_image_free(png_store *ps, png_const_structp pp)
 
 static void
 store_ensure_image(png_store *ps, png_const_structp pp, int nImages,
-   png_size_t cbRow, png_uint_32 cRows)
+   size_t cbRow, png_uint_32 cRows)
 {
-   png_size_t cb = nImages * cRows * (cbRow + 5);
+   size_t cb = nImages * cRows * (cbRow + 5);
 
    if (ps->cb_image < cb)
    {
@@ -1234,7 +1235,7 @@ store_image_check(const png_store* ps, png_const_structp pp, int iImage)
       png_error(pp, "image overwrite");
    else
    {
-      png_size_t cbRow = ps->cb_row;
+      size_t cbRow = ps->cb_row;
       png_uint_32 rows = ps->image_h;
 
       image += iImage * (cbRow+5) * ps->image_h;
@@ -1278,7 +1279,7 @@ valid_chunktype(png_uint_32 chunktype)
 }
 
 static void PNGCBAPI
-store_write(png_structp ppIn, png_bytep pb, png_size_t st)
+store_write(png_structp ppIn, png_bytep pb, size_t st)
 {
    png_const_structp pp = ppIn;
    png_store *ps = voidcast(png_store*, png_get_io_ptr(pp));
@@ -1346,13 +1347,13 @@ store_write(png_structp ppIn, png_bytep pb, png_size_t st)
 
       else /* chunkpos >= 8 */
       {
-         png_size_t cb = st;
+         size_t cb = st;
 
          if (cb > STORE_BUFFER_SIZE - writepos)
             cb = STORE_BUFFER_SIZE - writepos;
 
          if (cb  > chunklen - chunkpos/* bytes left in chunk*/)
-            cb = (png_size_t)/*SAFE*/(chunklen - chunkpos);
+            cb = (size_t)/*SAFE*/(chunklen - chunkpos);
 
          memcpy(ps->new.buffer + writepos, pb, cb);
          chunkpos += (png_uint_32)/*SAFE*/cb;
@@ -1440,7 +1441,7 @@ store_read_buffer_next(png_store *ps)
  * during progressive read, where the io_ptr is set internally by libpng.
  */
 static void
-store_read_imp(png_store *ps, png_bytep pb, png_size_t st)
+store_read_imp(png_store *ps, png_bytep pb, size_t st)
 {
    if (ps->current == NULL || ps->next == NULL)
       png_error(ps->pread, "store state damaged");
@@ -1463,14 +1464,13 @@ store_read_imp(png_store *ps, png_bytep pb, png_size_t st)
    }
 }
 
-static png_size_t
-store_read_chunk(png_store *ps, png_bytep pb, const png_size_t max,
-      const png_size_t min)
+static size_t
+store_read_chunk(png_store *ps, png_bytep pb, size_t max, size_t min)
 {
    png_uint_32 chunklen = ps->chunklen;
    png_uint_32 chunktype = ps->chunktype;
    png_uint_32 chunkpos = ps->chunkpos;
-   png_size_t st = max;
+   size_t st = max;
 
    if (st > 0) do
    {
@@ -1601,8 +1601,8 @@ store_read_chunk(png_store *ps, png_bytep pb, const png_size_t max,
 
                store_read_imp(ps, pb, avail);
                ps->IDAT_crc = crc32(ps->IDAT_crc, pb, avail);
-               pb += (png_size_t)/*SAFE*/avail;
-               st -= (png_size_t)/*SAFE*/avail;
+               pb += (size_t)/*SAFE*/avail;
+               st -= (size_t)/*SAFE*/avail;
                chunkpos += (png_uint_32)/*SAFE*/avail;
                IDAT_size -= (png_uint_32)/*SAFE*/avail;
                IDAT_pos += (png_uint_32)/*SAFE*/avail;
@@ -1669,10 +1669,10 @@ store_read_chunk(png_store *ps, png_bytep pb, const png_size_t max,
 
          else /* Return chunk bytes, including the CRC */
          {
-            png_size_t avail = st;
+            size_t avail = st;
 
             if (avail > chunklen - chunkpos)
-               avail = (png_size_t)/*SAFE*/(chunklen - chunkpos);
+               avail = (size_t)/*SAFE*/(chunklen - chunkpos);
 
             store_read_imp(ps, pb, avail);
             pb += avail;
@@ -1698,7 +1698,7 @@ store_read_chunk(png_store *ps, png_bytep pb, const png_size_t max,
 }
 
 static void PNGCBAPI
-store_read(png_structp ppIn, png_bytep pb, png_size_t st)
+store_read(png_structp ppIn, png_bytep pb, size_t st)
 {
    png_const_structp pp = ppIn;
    png_store *ps = voidcast(png_store*, png_get_io_ptr(pp));
@@ -1724,7 +1724,7 @@ store_progressive_read(png_store *ps, png_structp pp, png_infop pi)
    while (store_read_buffer_avail(ps) > 0)
    {
       static png_uint_32 noise = 2;
-      png_size_t cb;
+      size_t cb;
       png_byte buffer[512];
 
       /* Generate 15 more bits of stuff: */
@@ -2590,7 +2590,7 @@ static double digitize(double value, int depth, int do_round)
     * rounding and 'do_round' should be 1, if it is 0 the digitized value will
     * be truncated.
     */
-   const unsigned int digitization_factor = (1U << depth) -1;
+   unsigned int digitization_factor = (1U << depth) - 1;
 
    /* Limiting the range is done as a convenience to the caller - it's easier to
     * do it once here than every time at the call site.
@@ -2991,7 +2991,7 @@ modifier_setbuffer(png_modifier *pm)
  * png_struct.
  */
 static void
-modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
+modifier_read_imp(png_modifier *pm, png_bytep pb, size_t st)
 {
    while (st > 0)
    {
@@ -3137,7 +3137,7 @@ modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
              */
             if (len+12 <= sizeof pm->buffer)
             {
-               png_size_t s = len+12-pm->buffer_count;
+               size_t s = len+12-pm->buffer_count;
                store_read_chunk(&pm->this, pm->buffer+pm->buffer_count, s, s);
                pm->buffer_count = len+12;
 
@@ -3196,7 +3196,7 @@ modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
 
 /* The callback: */
 static void PNGCBAPI
-modifier_read(png_structp ppIn, png_bytep pb, png_size_t st)
+modifier_read(png_structp ppIn, png_bytep pb, size_t st)
 {
    png_const_structp pp = ppIn;
    png_modifier *pm = voidcast(png_modifier*, png_get_io_ptr(pp));
@@ -3226,7 +3226,7 @@ modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi)
    for (;;)
    {
       static png_uint_32 noise = 1;
-      png_size_t cb, cbAvail;
+      size_t cb, cbAvail;
       png_byte buffer[512];
 
       /* Generate 15 more bits of stuff: */
@@ -3688,8 +3688,8 @@ init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette,
 
 #ifdef PNG_WRITE_tRNS_SUPPORTED
 static void
-set_random_tRNS(png_structp pp, png_infop pi, const png_byte colour_type,
-   const int bit_depth)
+set_random_tRNS(png_structp pp, png_infop pi, png_byte colour_type,
+   int bit_depth)
 {
    /* To make this useful the tRNS color needs to match at least one pixel.
     * Random values are fine for gray, including the 16-bit case where we know
@@ -3697,7 +3697,7 @@ set_random_tRNS(png_structp pp, png_infop pi, const png_byte colour_type,
     * method as only 65536 different RGB values are generated.
     */
    png_color_16 tRNS;
-   const png_uint_16 mask = (png_uint_16)((1U << bit_depth)-1);
+   png_uint_16 mask = (png_uint_16)((1U << bit_depth)-1);
 
    R8(tRNS); /* makes unset fields random */
 
@@ -4010,8 +4010,11 @@ check_interlace_type(int const interlace_type)
 #  define do_own_interlace 1
 #endif /* WRITE_INTERLACING tests */
 
-#define CAN_WRITE_INTERLACE\
-   PNG_LIBPNG_VER >= 10700 || defined PNG_WRITE_INTERLACING_SUPPORTED
+#if PNG_LIBPNG_VER >= 10700 || defined PNG_WRITE_INTERLACING_SUPPORTED
+#   define CAN_WRITE_INTERLACE 1
+#else
+#   define CAN_WRITE_INTERLACE 0
+#endif
 
 /* Do the same thing for read interlacing; this controls whether read tests do
  * their own de-interlace or use libpng.
@@ -4335,7 +4338,7 @@ make_size_image(png_store* const ps, png_byte const colour_type,
 
       /* Make a name and get an appropriate id for the store: */
       char name[FILE_NAME_SIZE];
-      const png_uint_32 id = FILEID(colour_type, bit_depth, 0/*palette*/,
+      png_uint_32 id = FILEID(colour_type, bit_depth, 0/*palette*/,
          interlace_type, w, h, do_interlace);
 
       standard_name_from_id(name, sizeof name, 0, id);
@@ -4411,7 +4414,7 @@ make_size_image(png_store* const ps, png_byte const colour_type,
          for (pass=0; pass<npasses; ++pass)
          {
             /* The following two are for checking the macros: */
-            const png_uint_32 wPass = PNG_PASS_COLS(w, pass);
+            png_uint_32 wPass = PNG_PASS_COLS(w, pass);
 
             /* If do_interlace is set we don't call png_write_row for every
              * row because some of them are empty.  In fact, for a 1x1 image,
@@ -4643,7 +4646,7 @@ make_error(png_store* const ps, png_byte const colour_type,
    Try
    {
       png_infop pi;
-      const png_structp pp = set_store_for_write(ps, &pi, name);
+      png_structp pp = set_store_for_write(ps, &pi, name);
       png_uint_32 w, h;
       gnu_volatile(pp)
 
@@ -4703,7 +4706,7 @@ make_error(png_store* const ps, png_byte const colour_type,
       else
       {
          /* Now write the whole image, just to make sure that the detected, or
-          * undetected, errro has not created problems inside libpng.  This
+          * undetected, error has not created problems inside libpng.  This
           * doesn't work if there was a png_error in png_write_info because that
           * can abort before PLTE was written.
           */
@@ -4998,7 +5001,7 @@ standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id,
    dp->npalette = 0;
    /* Preset the transparent color to black: */
    memset(&dp->transparent, 0, sizeof dp->transparent);
-   /* Preset the palette to full intensity/opaque througout: */
+   /* Preset the palette to full intensity/opaque throughout: */
    memset(dp->palette, 0xff, sizeof dp->palette);
 }
 
@@ -5267,7 +5270,7 @@ standard_info_part1(standard_display *dp, png_structp pp, png_infop pi)
     */
    standard_palette_validate(dp, pp, pi);
 
-   /* In any case always check for a tranparent color (notice that the
+   /* In any case always check for a transparent color (notice that the
     * colour type 3 case must not give a successful return on the get_tRNS call
     * with these arguments!)
     */
@@ -5466,14 +5469,14 @@ progressive_row(png_structp ppIn, png_bytep new_row, png_uint_32 y, int pass)
 
 static void
 sequential_row(standard_display *dp, png_structp pp, png_infop pi,
-    const int iImage, const int iDisplay)
+    int iImage, int iDisplay)
 {
-   const int         npasses = dp->npasses;
-   const int         do_interlace = dp->do_interlace &&
+   int npasses = dp->npasses;
+   int do_interlace = dp->do_interlace &&
       dp->interlace_type == PNG_INTERLACE_ADAM7;
-   const png_uint_32 height = standard_height(pp, dp->id);
-   const png_uint_32 width = standard_width(pp, dp->id);
-   const png_store*  ps = dp->ps;
+   png_uint_32 height = standard_height(pp, dp->id);
+   png_uint_32 width = standard_width(pp, dp->id);
+   const png_store* ps = dp->ps;
    int pass;
 
    for (pass=0; pass<npasses; ++pass)
@@ -5867,7 +5870,7 @@ test_size(png_modifier* const pm, png_byte const colour_type,
     */
    static const png_byte hinc[] = {1, 3, 11, 1, 5};
    static const png_byte winc[] = {1, 9, 5, 7, 1};
-   const int save_bdlo = bdlo;
+   int save_bdlo = bdlo;
 
    for (; bdlo <= bdhi; ++bdlo)
    {
@@ -6075,12 +6078,12 @@ image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type,
     png_byte bit_depth, png_uint_32 x, store_palette palette,
     const image_pixel *format /*from pngvalid transform of input*/)
 {
-   const png_byte sample_depth = (png_byte)(colour_type ==
-      PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth);
-   const unsigned int max = (1U<<sample_depth)-1;
-   const int swap16 = (format != 0 && format->swap16);
-   const int littleendian = (format != 0 && format->littleendian);
-   const int sig_bits = (format != 0 && format->sig_bits);
+   png_byte sample_depth =
+      (png_byte)(colour_type == PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth);
+   unsigned int max = (1U<<sample_depth)-1;
+   int swap16 = (format != 0 && format->swap16);
+   int littleendian = (format != 0 && format->littleendian);
+   int sig_bits = (format != 0 && format->sig_bits);
 
    /* Initially just set everything to the same number and the alpha to opaque.
     * Note that this currently assumes a simple palette where entry x has colour
@@ -6098,7 +6101,7 @@ image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type,
       /* This permits the caller to default to the sample value. */
       if (palette != 0)
       {
-         const unsigned int i = this->palette_index;
+         unsigned int i = this->palette_index;
 
          this->red = palette[i].red;
          this->green = palette[i].green;
@@ -6429,8 +6432,8 @@ static void
 image_transform_mod_end(const image_transform *this, image_pixel *that,
     png_const_structp pp, const transform_display *display)
 {
-   const unsigned int scale = (1U<<that->sample_depth)-1;
-   const int sig_bits = that->sig_bits;
+   unsigned int scale = (1U<<that->sample_depth)-1;
+   int sig_bits = that->sig_bits;
 
    UNUSED(this)
    UNUSED(pp)
@@ -6581,16 +6584,16 @@ transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
    {
    case PNG_COLOR_TYPE_PALETTE:
       if (dp->output_bit_depth > 8) goto error;
-      /*FALL THROUGH*/
+      /* FALLTHROUGH */
    case PNG_COLOR_TYPE_GRAY:
       if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 ||
          dp->output_bit_depth == 4)
          break;
-      /*FALL THROUGH*/
+      /* FALLTHROUGH */
    default:
       if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16)
          break;
-      /*FALL THROUGH*/
+      /* FALLTHROUGH */
    error:
       {
          char message[128];
@@ -6753,19 +6756,19 @@ transform_image_validate(transform_display *dp, png_const_structp pp,
 {
    /* Constants for the loop below: */
    const png_store* const ps = dp->this.ps;
-   const png_byte in_ct = dp->this.colour_type;
-   const png_byte in_bd = dp->this.bit_depth;
-   const png_uint_32 w = dp->this.w;
-   const png_uint_32 h = dp->this.h;
-   const png_byte out_ct = dp->output_colour_type;
-   const png_byte out_bd = dp->output_bit_depth;
-   const png_byte sample_depth = (png_byte)(out_ct ==
-      PNG_COLOR_TYPE_PALETTE ? 8 : out_bd);
-   const png_byte red_sBIT = dp->this.red_sBIT;
-   const png_byte green_sBIT = dp->this.green_sBIT;
-   const png_byte blue_sBIT = dp->this.blue_sBIT;
-   const png_byte alpha_sBIT = dp->this.alpha_sBIT;
-   const int have_tRNS = dp->this.is_transparent;
+   png_byte in_ct = dp->this.colour_type;
+   png_byte in_bd = dp->this.bit_depth;
+   png_uint_32 w = dp->this.w;
+   png_uint_32 h = dp->this.h;
+   png_byte out_ct = dp->output_colour_type;
+   png_byte out_bd = dp->output_bit_depth;
+   png_byte sample_depth =
+      (png_byte)(out_ct == PNG_COLOR_TYPE_PALETTE ? 8 : out_bd);
+   png_byte red_sBIT = dp->this.red_sBIT;
+   png_byte green_sBIT = dp->this.green_sBIT;
+   png_byte blue_sBIT = dp->this.blue_sBIT;
+   png_byte alpha_sBIT = dp->this.alpha_sBIT;
+   int have_tRNS = dp->this.is_transparent;
    double digitization_error;
 
    store_palette out_palette;
@@ -6777,7 +6780,7 @@ transform_image_validate(transform_display *dp, png_const_structp pp,
    store_image_check(dp->this.ps, pp, 0);
 
    /* Read the palette corresponding to the output if the output colour type
-    * indicates a palette, othewise set out_palette to garbage.
+    * indicates a palette, otherwise set out_palette to garbage.
     */
    if (out_ct == PNG_COLOR_TYPE_PALETTE)
    {
@@ -6926,7 +6929,7 @@ transform_end(png_structp ppIn, png_infop pi)
 
 /* A single test run. */
 static void
-transform_test(png_modifier *pmIn, const png_uint_32 idIn,
+transform_test(png_modifier *pmIn, png_uint_32 idIn,
     const image_transform* transform_listIn, const char * const name)
 {
    transform_display d;
@@ -7739,13 +7742,11 @@ image_transform_png_set_rgb_to_gray_ini(const image_transform *this,
           * NOTE: this number only affects the internal limit check in pngvalid,
           * it has no effect on the limits applied to the libpng values.
           */
-         that->pm->limit += pow(
-#        if DIGITIZE
-            2.0
-#        else
-            1.0
-#        endif
-            /255, data.gamma);
+#if DIGITIZE
+          that->pm->limit += pow( 2.0/255, data.gamma);
+#else
+          that->pm->limit += pow( 1.0/255, data.gamma);
+#endif
       }
    }
 
@@ -7763,7 +7764,7 @@ static void
 image_transform_png_set_rgb_to_gray_set(const image_transform *this,
     transform_display *that, png_structp pp, png_infop pi)
 {
-   const int error_action = 1; /* no error, no defines in png.h */
+   int error_action = 1; /* no error, no defines in png.h */
 
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
       png_set_rgb_to_gray(pp, error_action, data.red_to_set, data.green_to_set);
@@ -7904,10 +7905,10 @@ image_transform_png_set_rgb_to_gray_mod(const image_transform *this,
 #  if DIGITIZE
       {
          png_modifier *pm = display->pm;
-         const unsigned int sample_depth = that->sample_depth;
-         const unsigned int calc_depth = (pm->assume_16_bit_calculations ? 16 :
+         unsigned int sample_depth = that->sample_depth;
+         unsigned int calc_depth = (pm->assume_16_bit_calculations ? 16 :
             sample_depth);
-         const unsigned int gamma_depth =
+         unsigned int gamma_depth =
             (sample_depth == 16 ?
                display->max_gamma_8 :
                (pm->assume_16_bit_calculations ?
@@ -7990,7 +7991,7 @@ image_transform_png_set_rgb_to_gray_mod(const image_transform *this,
          /* Now calculate the actual gray values.  Although the error in the
           * coefficients depends on whether they were specified on the command
           * line (in which case truncation to 15 bits happened) or not (rounding
-          * was used) the maxium error in an individual coefficient is always
+          * was used) the maximum error in an individual coefficient is always
           * 2/32768, because even in the rounding case the requirement that
           * coefficients add up to 32768 can cause a larger rounding error.
           *
@@ -8001,7 +8002,7 @@ image_transform_png_set_rgb_to_gray_mod(const image_transform *this,
             b * data.blue_coefficient;
 
          {
-            const int do_round = data.gamma != 1 || calc_depth == 16;
+            int do_round = data.gamma != 1 || calc_depth == 16;
             const double ce = 2. / 32768;
 
             graylo = DD(rlo * (data.red_coefficient-ce) +
@@ -8206,7 +8207,7 @@ image_transform_png_set_rgb_to_gray_mod(const image_transform *this,
       that->bluef = that->greenf = that->redf = gray;
       that->bluee = that->greene = that->rede = err;
 
-      /* The sBIT is the minium of the three colour channel sBITs. */
+      /* The sBIT is the minimum of the three colour channel sBITs. */
       if (that->red_sBIT > that->green_sBIT)
          that->red_sBIT = that->green_sBIT;
       if (that->red_sBIT > that->blue_sBIT)
@@ -8625,7 +8626,7 @@ image_transform_png_set_filler_mod(const image_transform *this,
        (that->colour_type == PNG_COLOR_TYPE_RGB ||
         that->colour_type == PNG_COLOR_TYPE_GRAY))
    {
-      const unsigned int max = (1U << that->bit_depth)-1;
+      unsigned int max = (1U << that->bit_depth)-1;
       that->alpha = data.filler & max;
       that->alphaf = ((double)that->alpha) / max;
       that->alphae = 0;
@@ -8692,7 +8693,7 @@ image_transform_png_set_add_alpha_mod(const image_transform *this,
        (that->colour_type == PNG_COLOR_TYPE_RGB ||
         that->colour_type == PNG_COLOR_TYPE_GRAY))
    {
-      const unsigned int max = (1U << that->bit_depth)-1;
+      unsigned int max = (1U << that->bit_depth)-1;
       that->alpha = data.filler & max;
       that->alphaf = ((double)that->alpha) / max;
       that->alphae = 0;
@@ -8883,7 +8884,7 @@ image_transform_png_set_shift_set(const image_transform *this,
     * field is randomized independently.  This acts as a check that
     * libpng does use the correct field.
     */
-   const unsigned int depth = that->this.bit_depth;
+   unsigned int depth = that->this.bit_depth;
 
    data.red = (png_byte)/*SAFE*/(random_mod(depth)+1);
    data.green = (png_byte)/*SAFE*/(random_mod(depth)+1);
@@ -9298,12 +9299,12 @@ gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi)
          int mode = dp->do_background - ALPHA_MODE_OFFSET;
 
          /* The gamma value is the output gamma, and is in the standard,
-          * non-inverted, represenation.  It provides a default for the PNG file
+          * non-inverted, representation.  It provides a default for the PNG file
           * gamma, but since the file has a gAMA chunk this does not matter.
           */
          const double sg = dp->screen_gamma;
 #        ifndef PNG_FLOATING_POINT_SUPPORTED
-            const png_fixed_point g = fix(sg);
+            png_fixed_point g = fix(sg);
 #        endif
 
 #        ifdef PNG_FLOATING_POINT_SUPPORTED
@@ -9351,7 +9352,7 @@ gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi)
           */
          const double bg = dp->background_gamma;
 #        ifndef PNG_FLOATING_POINT_SUPPORTED
-            const png_fixed_point g = fix(bg);
+            png_fixed_point g = fix(bg);
 #        endif
 
 #        ifdef PNG_FLOATING_POINT_SUPPORTED
@@ -9425,7 +9426,7 @@ static void
 init_validate_info(validate_info *vi, gamma_display *dp, png_const_structp pp,
     int in_depth, int out_depth)
 {
-   const unsigned int outmax = (1U<<out_depth)-1;
+   unsigned int outmax = (1U<<out_depth)-1;
 
    vi->pp = pp;
    vi->dp = dp;
@@ -9587,14 +9588,14 @@ gamma_component_compose(int do_background, double input_sample, double alpha,
 /* This API returns the encoded *input* component, in the range 0..1 */
 static double
 gamma_component_validate(const char *name, const validate_info *vi,
-    const unsigned int id, const unsigned int od,
+    unsigned int id, unsigned int od,
     const double alpha /* <0 for the alpha channel itself */,
     const double background /* component background value */)
 {
-   const unsigned int isbit = id >> vi->isbit_shift;
-   const unsigned int sbit_max = vi->sbit_max;
-   const unsigned int outmax = vi->outmax;
-   const int do_background = vi->do_background;
+   unsigned int isbit = id >> vi->isbit_shift;
+   unsigned int sbit_max = vi->sbit_max;
+   unsigned int outmax = vi->outmax;
+   int do_background = vi->do_background;
 
    double i;
 
@@ -9745,7 +9746,7 @@ gamma_component_validate(const char *name, const validate_info *vi,
        *
        * pngvalid calculations:
        *  input_sample: linear result; i linearized and composed, range 0..1
-       *  encoded_sample: encoded result; input_sample scaled to ouput bit depth
+       *  encoded_sample: encoded result; input_sample scaled to output bit depth
        *
        * libpng calculations:
        *  output: linear result; od scaled to 0..1 and linearized
@@ -9993,9 +9994,9 @@ gamma_component_validate(const char *name, const validate_info *vi,
                case PNG_BACKGROUND_GAMMA_FILE:
                case PNG_BACKGROUND_GAMMA_UNIQUE:
                   use_background = (alpha >= 0 && alpha < 1);
-                  /*FALL THROUGH*/
 #           endif
 #           ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+               /* FALLTHROUGH */
                case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
                case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
                case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED:
@@ -10160,13 +10161,13 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
 {
    /* Get some constants derived from the input and output file formats: */
    const png_store* const ps = dp->this.ps;
-   const png_byte in_ct = dp->this.colour_type;
-   const png_byte in_bd = dp->this.bit_depth;
-   const png_uint_32 w = dp->this.w;
-   const png_uint_32 h = dp->this.h;
+   png_byte in_ct = dp->this.colour_type;
+   png_byte in_bd = dp->this.bit_depth;
+   png_uint_32 w = dp->this.w;
+   png_uint_32 h = dp->this.h;
    const size_t cbRow = dp->this.cbRow;
-   const png_byte out_ct = png_get_color_type(pp, pi);
-   const png_byte out_bd = png_get_bit_depth(pp, pi);
+   png_byte out_ct = png_get_color_type(pp, pi);
+   png_byte out_bd = png_get_bit_depth(pp, pi);
 
    /* There are three sources of error, firstly the quantization in the
     * file encoding, determined by sbit and/or the file depth, secondly
@@ -10182,10 +10183,10 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
     * Since the library must quantize the output to 8 or 16 bits there is
     * a fundamental limit on the accuracy of the output of +/-.5 - this
     * quantization limit is included in addition to the other limits
-    * specified by the paramaters to the API.  (Effectively, add .5
+    * specified by the parameters to the API.  (Effectively, add .5
     * everywhere.)
     *
-    * The behavior of the 'sbit' paramter is defined by section 12.5
+    * The behavior of the 'sbit' parameter is defined by section 12.5
     * (sample depth scaling) of the PNG spec.  That section forces the
     * decoder to assume that the PNG values have been scaled if sBIT is
     * present:
@@ -10207,11 +10208,11 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
     * The basic tests below do not do this, however if 'use_input_precision'
     * is set a subsequent test is performed above.
     */
-   const unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U;
+   unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U;
    int processing;
    png_uint_32 y;
    const store_palette_entry *in_palette = dp->this.palette;
-   const int in_is_transparent = dp->this.is_transparent;
+   int in_is_transparent = dp->this.is_transparent;
    int process_tRNS;
    int out_npalette = -1;
    int out_is_transparent = 0; /* Just refers to the palette case */
@@ -10259,9 +10260,9 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
             double alpha = 1; /* serves as a flag value */
 
             /* Record the palette index for index images. */
-            const unsigned int in_index =
+            unsigned int in_index =
                in_ct == 3 ? sample(std, 3, in_bd, x, 0, 0, 0) : 256;
-            const unsigned int out_index =
+            unsigned int out_index =
                out_ct == 3 ? sample(std, 3, out_bd, x, 0, 0, 0) : 256;
 
             /* Handle input alpha - png_set_background will cause the output
@@ -10270,7 +10271,7 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
             if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 ||
                 (in_ct == 3 && in_is_transparent))
             {
-               const unsigned int input_alpha = in_ct == 3 ?
+               unsigned int input_alpha = in_ct == 3 ?
                   dp->this.palette[in_index].alpha :
                   sample(std, in_ct, in_bd, x, samples_per_pixel, 0, 0);
 
@@ -10395,14 +10396,14 @@ gamma_end(png_structp ppIn, png_infop pi)
  * maxpc:  maximum percentage error (as a percentage)
  */
 static void
-gamma_test(png_modifier *pmIn, const png_byte colour_typeIn,
-    const png_byte bit_depthIn, const int palette_numberIn,
-    const int interlace_typeIn,
+gamma_test(png_modifier *pmIn, png_byte colour_typeIn,
+    png_byte bit_depthIn, int palette_numberIn,
+    int interlace_typeIn,
     const double file_gammaIn, const double screen_gammaIn,
-    const png_byte sbitIn, const int threshold_testIn,
+    png_byte sbitIn, int threshold_testIn,
     const char *name,
-    const int use_input_precisionIn, const int scale16In,
-    const int expand16In, const int do_backgroundIn,
+    int use_input_precisionIn, int scale16In,
+    int expand16In, int do_backgroundIn,
     const png_color_16 *bkgd_colorIn, double bkgd_gammaIn)
 {
    gamma_display d;
@@ -10606,11 +10607,11 @@ perform_gamma_threshold_tests(png_modifier *pm)
 }
 
 static void gamma_transform_test(png_modifier *pm,
-   const png_byte colour_type, const png_byte bit_depth,
-   const int palette_number,
-   const int interlace_type, const double file_gamma,
-   const double screen_gamma, const png_byte sbit,
-   const int use_input_precision, const int scale16)
+   png_byte colour_type, png_byte bit_depth,
+   int palette_number,
+   int interlace_type, const double file_gamma,
+   const double screen_gamma, png_byte sbit,
+   int use_input_precision, int scale16)
 {
    size_t pos = 0;
    char name[64];
@@ -10767,12 +10768,12 @@ static void perform_gamma_scale16_tests(png_modifier *pm)
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
    defined(PNG_READ_ALPHA_MODE_SUPPORTED)
 static void gamma_composition_test(png_modifier *pm,
-   const png_byte colour_type, const png_byte bit_depth,
-   const int palette_number,
-   const int interlace_type, const double file_gamma,
+   png_byte colour_type, png_byte bit_depth,
+   int palette_number,
+   int interlace_type, const double file_gamma,
    const double screen_gamma,
-   const int use_input_precision, const int do_background,
-   const int expand_16)
+   int use_input_precision, int do_background,
+   int expand_16)
 {
    size_t pos = 0;
    png_const_charp base;
@@ -11728,7 +11729,7 @@ int main(int argc, char **argv)
 
    /* Some default values (set the behavior for 'make check' here).
     * These values simply control the maximum error permitted in the gamma
-    * transformations.  The practial limits for human perception are described
+    * transformations.  The practical limits for human perception are described
     * below (the setting for maxpc16), however for 8 bit encodings it isn't
     * possible to meet the accepted capabilities of human vision - i.e. 8 bit
     * images can never be good enough, regardless of encoding.

contrib/libtests/readpng.c

@@ -60,7 +60,7 @@ read_png(FILE *fp)
    png_read_info(png_ptr, info_ptr);
 
    {
-      png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+      size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
 
       /* Failure to initialize these is harmless */
       row = malloc(rowbytes);

contrib/libtests/tarith.c

@@ -108,7 +108,7 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
 
    do
    {
-      png_size_t index;
+      size_t index;
       int state, failed = 0;
       char buffer[64];
 
@@ -176,7 +176,7 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
       }
       else if (PNG_FP_IS_POSITIVE(state) && !(test > 0))
       {
-         fprintf(stderr, "%g[%d] -> '%s' but postive value not so reported\n",
+         fprintf(stderr, "%g[%d] -> '%s' but positive value not so reported\n",
             test, precision, buffer);
          failed = 1;
          assert(!PNG_FP_IS_NEGATIVE(state));
@@ -329,10 +329,10 @@ static int check_one_character(checkfp_command *co, checkfp_control c, int ch)
 {
    /* Test this character (ch) to ensure the parser does the correct thing.
     */
-   png_size_t index = 0;
+   size_t index = 0;
    const char test = (char)ch;
-   const int number_is_valid = png_check_fp_number(&test, 1, &c.state, &index);
-   const int character_accepted = (index == 1);
+   int number_is_valid = png_check_fp_number(&test, 1, &c.state, &index);
+   int character_accepted = (index == 1);
 
    if (c.check_state != exponent && isdigit(ch) && ch != '0')
       c.is_zero = 0;

contrib/libtests/timepng.c

@@ -65,7 +65,7 @@ typedef struct
 }  io_data;
 
 static PNG_CALLBACK(void, read_and_copy,
-      (png_structp png_ptr, png_bytep buffer, png_size_t cb))
+      (png_structp png_ptr, png_bytep buffer, size_t cb))
 {
    io_data *io = (io_data*)png_get_io_ptr(png_ptr);
 
@@ -100,7 +100,7 @@ static void read_by_row(png_structp png_ptr, png_infop info_ptr,
    png_read_info(png_ptr, info_ptr);
 
    {
-      png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+      size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
 
       row = voidcast(png_bytep,malloc(rowbytes));
       display = voidcast(png_bytep,malloc(rowbytes));

contrib/oss-fuzz/Dockerfile

@@ -0,0 +1,25 @@
+# Copyright 2016 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+################################################################################
+
+FROM gcr.io/oss-fuzz-base/base-builder
+MAINTAINER glennrp@gmail.com
+RUN apt-get update && \
+    apt-get install -y make autoconf automake libtool
+
+RUN git clone --depth 1 https://github.com/madler/zlib.git
+RUN git clone --depth 1 https://github.com/glennrp/libpng.git
+RUN cp libpng/contrib/oss-fuzz/build.sh $SRC
+WORKDIR libpng

contrib/oss-fuzz/README.txt

@@ -0,0 +1,37 @@
+Last changed in libpng 1.6.33 [September 28, 2017]
+Copyright (c) 2017 Glenn Randers-Pehrson
+
+This code is released under the libpng license.
+For conditions of distribution and use, see the disclaimer
+and license in png.h
+
+Files in this directory are used by the oss-fuzz project
+(https://github.com/google/oss-fuzz/tree/master/projects/libpng).
+for "fuzzing" libpng.
+
+They were licensed by Google Inc, using the BSD-like Chromium license,
+which may be found at https://cs.chromium.org/chromium/src/LICENSE, or, if
+noted in the source, under the Apache-2.0 license, which may
+be found at http://www.apache.org/licenses/LICENSE-2.0 .
+If they have been modified, the derivatives are copyright Glenn Randers-Pehrson
+and are released under the same licenses as the originals.  Several of
+the original files (libpng_read_fuzzer.options, png.dict, project.yaml)
+had no licensing information; we assumed that these were under the Chromium
+license. Any new files are released under the libpng license (see png.h).
+
+The files are
+                            Original
+ Filename                   or derived   Copyright          License
+ =========================  ==========   ================   ==========
+ Dockerfile*                derived      2017, Glenn R-P    Apache 2.0
+ build.sh                   derived      2017, Glenn R-P    Apache 2.0
+ libpng_read_fuzzer.cc      derived      2017, Glenn R-P    Chromium
+ libpng_read_fuzzer.options original     2015, Chrome Devs  Chromium
+ png.dict                   original     2015, Chrome Devs  Chromium
+ README.txt (this file)     original     2017, Glenn R-P    libpng
+
+ * Dockerfile is a copy of the file used by oss-fuzz. build.sh,
+   png.dict and libpng_read_fuzzer.* are the actual files used by oss-fuzz,
+   which retrieves them from the libpng repository at Github.
+
+To do: exercise the progressive reader and the png encoder.

contrib/oss-fuzz/build.sh

@@ -0,0 +1,51 @@
+#!/bin/bash -eu
+# Copyright 2017-2018 Glenn Randers-Pehrson
+# Copyright 2016 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Last changed in libpng 1.6.35 [July 15, 2018]
+#
+# Revisions by Glenn Randers-Pehrson, 2017:
+# 1. Build only the library, not the tools (changed "make -j$(nproc) all" to
+#     "make -j$(nproc) libpng16.la").
+# 2. Disabled WARNING and WRITE options in pnglibconf.dfa.
+# 3. Build zlib alongside libpng
+################################################################################
+
+# Disable logging via library build configuration control.
+cat scripts/pnglibconf.dfa | \
+  sed -e "s/option STDIO/option STDIO disabled/" \
+      -e "s/option WARNING /option WARNING disabled/" \
+      -e "s/option WRITE enables WRITE_INT_FUNCTIONS/option WRITE disabled/" \
+> scripts/pnglibconf.dfa.temp
+mv scripts/pnglibconf.dfa.temp scripts/pnglibconf.dfa
+
+# build the libpng library.
+autoreconf -f -i
+./configure --with-libpng-prefix=OSS_FUZZ_
+make -j$(nproc) clean
+make -j$(nproc) libpng16.la
+
+# build libpng_read_fuzzer.
+$CXX $CXXFLAGS -std=c++11 -I. \
+     $SRC/libpng/contrib/oss-fuzz/libpng_read_fuzzer.cc \
+     -o $OUT/libpng_read_fuzzer \
+     -lFuzzingEngine .libs/libpng16.a -lz
+
+# add seed corpus.
+find $SRC/libpng -name "*.png" | grep -v crashers | \
+     xargs zip $OUT/libpng_read_fuzzer_seed_corpus.zip
+
+cp $SRC/libpng/contrib/oss-fuzz/*.dict \
+     $SRC/libpng/contrib/oss-fuzz/*.options $OUT/

contrib/oss-fuzz/libpng_read_fuzzer.cc

@@ -0,0 +1,190 @@
+
+// libpng_read_fuzzer.cc
+// Copyright 2017-2018 Glenn Randers-Pehrson
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that may
+// be found in the LICENSE file https://cs.chromium.org/chromium/src/LICENSE
+
+// Last changed in libpng 1.6.35 [July 15, 2018]
+
+// The modifications in 2017 by Glenn Randers-Pehrson include
+// 1. addition of a PNG_CLEANUP macro,
+// 2. setting the option to ignore ADLER32 checksums,
+// 3. adding "#include <string.h>" which is needed on some platforms
+//    to provide memcpy().
+// 4. adding read_end_info() and creating an end_info structure.
+// 5. adding calls to png_set_*() transforms commonly used by browsers.
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <vector>
+
+#define PNG_INTERNAL
+#include "png.h"
+
+#define PNG_CLEANUP \
+  if(png_handler.png_ptr) \
+  { \
+    if (png_handler.row_ptr) \
+      png_free(png_handler.png_ptr, png_handler.row_ptr); \
+    if (png_handler.end_info_ptr) \
+      png_destroy_read_struct(&png_handler.png_ptr, &png_handler.info_ptr,\
+        &png_handler.end_info_ptr); \
+    else if (png_handler.info_ptr) \
+      png_destroy_read_struct(&png_handler.png_ptr, &png_handler.info_ptr,\
+        nullptr); \
+    else \
+      png_destroy_read_struct(&png_handler.png_ptr, nullptr, nullptr); \
+    png_handler.png_ptr = nullptr; \
+    png_handler.row_ptr = nullptr; \
+    png_handler.info_ptr = nullptr; \
+    png_handler.end_info_ptr = nullptr; \
+  }
+
+struct BufState {
+  const uint8_t* data;
+  size_t bytes_left;
+};
+
+struct PngObjectHandler {
+  png_infop info_ptr = nullptr;
+  png_structp png_ptr = nullptr;
+  png_infop end_info_ptr = nullptr;
+  png_voidp row_ptr = nullptr;
+  BufState* buf_state = nullptr;
+
+  ~PngObjectHandler() {
+    if (row_ptr)
+      png_free(png_ptr, row_ptr);
+    if (end_info_ptr)
+      png_destroy_read_struct(&png_ptr, &info_ptr, &end_info_ptr);
+    else if (info_ptr) 
+      png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
+    else
+      png_destroy_read_struct(&png_ptr, nullptr, nullptr);
+    delete buf_state;
+  }
+};
+
+void user_read_data(png_structp png_ptr, png_bytep data, size_t length) {
+  BufState* buf_state = static_cast<BufState*>(png_get_io_ptr(png_ptr));
+  if (length > buf_state->bytes_left) {
+    png_error(png_ptr, "read error");
+  }
+  memcpy(data, buf_state->data, length);
+  buf_state->bytes_left -= length;
+  buf_state->data += length;
+}
+
+static const int kPngHeaderSize = 8;
+
+// Entry point for LibFuzzer.
+// Roughly follows the libpng book example:
+// http://www.libpng.org/pub/png/book/chapter13.html
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  if (size < kPngHeaderSize) {
+    return 0;
+  }
+
+  std::vector<unsigned char> v(data, data + size);
+  if (png_sig_cmp(v.data(), 0, kPngHeaderSize)) {
+    // not a PNG.
+    return 0;
+  }
+
+  PngObjectHandler png_handler;
+  png_handler.png_ptr = nullptr;
+  png_handler.row_ptr = nullptr;
+  png_handler.info_ptr = nullptr;
+  png_handler.end_info_ptr = nullptr;
+
+  png_handler.png_ptr = png_create_read_struct
+    (PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
+  if (!png_handler.png_ptr) {
+    return 0;
+  }
+
+  png_handler.info_ptr = png_create_info_struct(png_handler.png_ptr);
+  if (!png_handler.info_ptr) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  png_handler.end_info_ptr = png_create_info_struct(png_handler.png_ptr);
+  if (!png_handler.end_info_ptr) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  png_set_crc_action(png_handler.png_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
+#ifdef PNG_IGNORE_ADLER32
+  png_set_option(png_handler.png_ptr, PNG_IGNORE_ADLER32, PNG_OPTION_ON);
+#endif
+
+  // Setting up reading from buffer.
+  png_handler.buf_state = new BufState();
+  png_handler.buf_state->data = data + kPngHeaderSize;
+  png_handler.buf_state->bytes_left = size - kPngHeaderSize;
+  png_set_read_fn(png_handler.png_ptr, png_handler.buf_state, user_read_data);
+  png_set_sig_bytes(png_handler.png_ptr, kPngHeaderSize);
+
+  if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  // Reading.
+  png_read_info(png_handler.png_ptr, png_handler.info_ptr);
+
+  // reset error handler to put png_deleter into scope.
+  if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  png_uint_32 width, height;
+  int bit_depth, color_type, interlace_type, compression_type;
+  int filter_type;
+
+  if (!png_get_IHDR(png_handler.png_ptr, png_handler.info_ptr, &width,
+                    &height, &bit_depth, &color_type, &interlace_type,
+                    &compression_type, &filter_type)) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  // This is going to be too slow.
+  if (width && height > 100000000 / width) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  // Set several transforms that browsers typically use:
+  png_set_gray_to_rgb(png_handler.png_ptr);
+  png_set_expand(png_handler.png_ptr);
+  png_set_packing(png_handler.png_ptr);
+  png_set_scale_16(png_handler.png_ptr);
+  png_set_tRNS_to_alpha(png_handler.png_ptr);
+
+  int passes = png_set_interlace_handling(png_handler.png_ptr);
+
+  png_read_update_info(png_handler.png_ptr, png_handler.info_ptr);
+
+  png_handler.row_ptr = png_malloc(
+      png_handler.png_ptr, png_get_rowbytes(png_handler.png_ptr,
+                                            png_handler.info_ptr));
+
+  for (int pass = 0; pass < passes; ++pass) {
+    for (png_uint_32 y = 0; y < height; ++y) {
+      png_read_row(png_handler.png_ptr,
+                   static_cast<png_bytep>(png_handler.row_ptr), nullptr);
+    }
+  }
+
+  png_read_end(png_handler.png_ptr, png_handler.end_info_ptr);
+
+  PNG_CLEANUP
+  return 0;
+}

contrib/oss-fuzz/libpng_read_fuzzer.options

@@ -0,0 +1,2 @@
+[libfuzzer]
+dict = png.dict

contrib/oss-fuzz/png.dict

@@ -0,0 +1,39 @@
+#
+# AFL dictionary for PNG images
+# -----------------------------
+#
+# Just the basic, standard-originating sections; does not include vendor
+# extensions.
+#
+# Created by Michal Zalewski <lcamtuf@google.com>
+#
+
+header_png="\x89PNG\x0d\x0a\x1a\x0a"
+
+section_IDAT="IDAT"
+section_IEND="IEND"
+section_IHDR="IHDR"
+section_PLTE="PLTE"
+section_bKGD="bKGD"
+section_cHRM="cHRM"
+section_eXIf="eXIf"
+section_fRAc="fRAc"
+section_gAMA="gAMA"
+section_gIFg="gIFg"
+section_gIFt="gIFt"
+section_gIFx="gIFx"
+section_hIST="hIST"
+section_iCCP="iCCP"
+section_iTXt="iTXt"
+section_oFFs="oFFs"
+section_pCAL="pCAL"
+section_pHYs="pHYs"
+section_sBIT="sBIT"
+section_sCAL="sCAL"
+section_sPLT="sPLT"
+section_sRGB="sRGB"
+section_sTER="sTER"
+section_tEXt="tEXt"
+section_tIME="tIME"
+section_tRNS="tRNS"
+section_zTXt="zTXt"

contrib/pngminus/README

@@ -17,7 +17,7 @@ express or implied warranty.
 Some history
 ------------
 Soon after the creation of PNG in 1995, the need was felt for a set of
-pnmtopng / pngtopnm utilities. Independantly Alexander Lehmann and I
+pnmtopng / pngtopnm utilities. Independently Alexander Lehmann and I
 (Willem van Schaik) started such a project. Luckily we discovered this
 and merged the two together into pnmtopng.tar.gz, which is available
 from a/o ftp://ftp.simplesystems.org/pub/libpng/png/.

contrib/pngminus/png2pnm.bat

@@ -7,7 +7,7 @@ png2pnm.exe -noraw ..\pngsuite\basn0g16.png basn0g16.pgm
 REM -- full-color
 png2pnm.exe -noraw ..\pngsuite\basn2c08.png basn2c08.ppm
 png2pnm.exe -noraw ..\pngsuite\basn2c16.png basn2c16.ppm
-REM -- palletted
+REM -- paletted
 png2pnm.exe -noraw ..\pngsuite\basn3p01.png basn3p01.ppm
 png2pnm.exe -noraw ..\pngsuite\basn3p02.png basn3p02.ppm
 png2pnm.exe -noraw ..\pngsuite\basn3p04.png basn3p04.ppm
@@ -27,7 +27,7 @@ png2pnm.exe -raw ..\pngsuite\basn0g16.png rawn0g16.pgm
 REM -- full-color
 png2pnm.exe -raw ..\pngsuite\basn2c08.png rawn2c08.ppm
 png2pnm.exe -raw ..\pngsuite\basn2c16.png rawn2c16.ppm
-REM -- palletted
+REM -- paletted
 png2pnm.exe -raw ..\pngsuite\basn3p01.png rawn3p01.ppm
 png2pnm.exe -raw ..\pngsuite\basn3p02.png rawn3p02.ppm
 png2pnm.exe -raw ..\pngsuite\basn3p04.png rawn3p04.ppm

contrib/pngminus/png2pnm.c

@@ -1,8 +1,12 @@
 /*
  *  png2pnm.c --- conversion from PNG-file to PGM/PPM-file
- *  copyright (C) 1999 by Willem van Schaik <willem at schaik.com>
+ *  copyright (C) 1999,2017 by Willem van Schaik <willem at schaik.com>
  *
  *  version 1.0 - 1999.10.15 - First version.
+ *          1.1 - 2017.04.22 - Add buffer-size check (Glenn Randers-Pehrson)
+ *          1.2 - 2017.08.24 - Fix potential overflow in buffer-size check
+ *                             (Glenn Randers-Pehrson)
+ *          1.3 - 2017.08.28 - Add PNGMINUS_UNUSED (Christian Hesse)
  *
  *  Permission to use, copy, modify, and distribute this software and
  *  its documentation for any purpose and without fee is hereby granted,
@@ -41,6 +45,7 @@
 #define PNG_DEBUG 0
 #endif
 
+
 #include "png.h"
 
 /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
@@ -48,6 +53,14 @@
 #  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
 #endif
 
+#ifndef PNGMINUS_UNUSED
+/* Unused formal parameter warnings are silenced using the following macro
+ * which is expected to have no bad effects on performance (optimizing
+ * compilers will probably remove it entirely).
+ */
+#  define PNGMINUS_UNUSED(param) (void)param
+#endif
+
 /* function prototypes */
 
 int  main (int argc, char *argv[]);
@@ -320,14 +333,21 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
   /* row_bytes is the width x number of channels x (bit-depth / 8) */
   row_bytes = png_get_rowbytes (png_ptr, info_ptr);
 
+  if ((row_bytes == 0 || (size_t)height > ((size_t)(-1))/(size_t)row_bytes))
+  {
+    /* too big */ 
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
   if ((png_pixels = (png_byte *)
-     malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
+     malloc ((size_t)row_bytes * (size_t)height * sizeof (png_byte))) == NULL)
+  {
     png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
     return FALSE;
   }
 
   if ((row_pointers = (png_byte **)
-     malloc (height * sizeof (png_bytep))) == NULL)
+     malloc ((size_t)height * sizeof (png_bytep))) == NULL)
   {
     png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
     free (png_pixels);
@@ -408,7 +428,8 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
           if (raw)
             fputc ((int) *pix_ptr++ , alpha_file);
           else
-            if (bit_depth == 16){
+            if (bit_depth == 16)
+            {
               dep_16 = (long) *pix_ptr++;
               fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
             }
@@ -432,6 +453,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
   if (png_pixels != (unsigned char*) NULL)
     free (png_pixels);
 
+  PNGMINUS_UNUSED(raw); /* to quiet a Coverity defect */
   return TRUE;
 
 } /* end of source */

contrib/pngminus/png2pnm.sh

@@ -8,7 +8,7 @@
 # -- full-color
 ./png2pnm -noraw ../pngsuite/basn2c08.png basn2c08.ppm
 ./png2pnm -noraw ../pngsuite/basn2c16.png basn2c16.ppm
-# -- palletted
+# -- paletted
 ./png2pnm -noraw ../pngsuite/basn3p01.png basn3p01.ppm
 ./png2pnm -noraw ../pngsuite/basn3p02.png basn3p02.ppm
 ./png2pnm -noraw ../pngsuite/basn3p04.png basn3p04.ppm
@@ -28,7 +28,7 @@
 # -- full-color
 ./png2pnm -raw ../pngsuite/basn2c08.png rawn2c08.ppm
 ./png2pnm -raw ../pngsuite/basn2c16.png rawn2c16.ppm
-# -- palletted
+# -- paletted
 ./png2pnm -raw ../pngsuite/basn3p01.png rawn3p01.ppm
 ./png2pnm -raw ../pngsuite/basn3p02.png rawn3p02.ppm
 ./png2pnm -raw ../pngsuite/basn3p04.png rawn3p04.ppm

contrib/pngminus/pnm2png.bat

@@ -7,7 +7,7 @@ pnm2png.exe basn0g16.pgm basn0g16.png
 REM -- full-color
 pnm2png.exe basn2c08.ppm basn2c08.png
 pnm2png.exe basn2c16.ppm basn2c16.png
-REM -- palletted
+REM -- paletted
 pnm2png.exe basn3p01.ppm basn3p01.png
 pnm2png.exe basn3p02.ppm basn3p02.png
 pnm2png.exe basn3p04.ppm basn3p04.png
@@ -27,7 +27,7 @@ pnm2png.exe rawn0g16.pgm rawn0g16.png
 REM -- full-color
 pnm2png.exe rawn2c08.ppm rawn2c08.png
 pnm2png.exe rawn2c16.ppm rawn2c16.png
-REM -- palletted
+REM -- paletted
 pnm2png.exe rawn3p01.ppm rawn3p01.png
 pnm2png.exe rawn3p02.ppm rawn3p02.png
 pnm2png.exe rawn3p04.ppm rawn3p04.png

contrib/pngminus/pnm2png.c

@@ -1,9 +1,13 @@
 /*
  *  pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file
- *  copyright (C) 1999 by Willem van Schaik <willem at schaik.com>
+ *  copyright (C) 1999,2015,2017 by Willem van Schaik <willem at schaik.com>
  *
  *  version 1.0 - 1999.10.15 - First version.
  *  version 1.1 - 2015.07.29 - Fixed leaks (Glenn Randers-Pehrson)
+ *  version 1.2 - 2017.04.22 - Add buffer-size check
+ *          1.3 - 2017.08.24 - Fix potential overflow in buffer-size check
+ *                             (Glenn Randers-Pehrson)
+ *          1.4 - 2017.08.28 - Add PNGMINUS_UNUSED (Christian Hesse)
  *
  *  Permission to use, copy, modify, and distribute this software and
  *  its documentation for any purpose and without fee is hereby granted,
@@ -47,6 +51,15 @@
 #  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
 #endif
 
+#ifndef PNGMINUS_UNUSED
+/* Unused formal parameter warnings are silenced using the following macro
+ * which is expected to have no bad effects on performance (optimizing
+ * compilers will probably remove it entirely).
+ */
+#  define PNGMINUS_UNUSED(param) (void)param
+#endif
+
+
 /* function prototypes */
 
 int  main (int argc, char *argv[]);
@@ -370,11 +383,16 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
     row_bytes = (width * channels * bit_depth + 7) / 8;
   else
 #endif
-    /* row_bytes is the width x number of channels x (bit-depth / 8) */
+  /* row_bytes is the width x number of channels x (bit-depth / 8) */
     row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
 
+  if ((row_bytes == 0 || (size_t)height > ((size_t)(-1))/(size_t)row_bytes))
+  {
+    /* too big */ 
+    return FALSE;
+  }
   if ((png_pixels = (png_byte *)
-     malloc (row_bytes * height * sizeof (png_byte))) == NULL)
+     malloc ((size_t)row_bytes * (size_t)height * sizeof (png_byte))) == NULL)
     return FALSE;
 
   /* read data from PNM file */
@@ -383,7 +401,8 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   for (row = 0; row < (int) height; row++)
   {
 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
-    if (packed_bitmap) {
+    if (packed_bitmap)
+    {
       for (i = 0; i < (int) row_bytes; i++)
         /* png supports this format natively so no conversion is needed */
         *pix_ptr++ = get_data (pnm_file, 8);
@@ -504,6 +523,8 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   if (png_pixels != (unsigned char*) NULL)
     free (png_pixels);
 
+  PNGMINUS_UNUSED(raw); /* Quiet a Coverity defect */
+
   return TRUE;
 } /* end of pnm2png */
 
@@ -520,7 +541,8 @@ void get_token(FILE *pnm_file, char *token)
   do
   {
     ret = fgetc(pnm_file);
-    if (ret == '#') {
+    if (ret == '#')
+    {
       /* the rest of this line is a comment */
       do
       {

contrib/pngminus/pnm2png.sh

@@ -8,7 +8,7 @@
 # -- full-color
 ./pnm2png basn2c08.ppm basn2c08.png
 ./pnm2png basn2c16.ppm basn2c16.png
-# -- palletted
+# -- paletted
 ./pnm2png basn3p01.ppm basn3p01.png
 ./pnm2png basn3p02.ppm basn3p02.png
 ./pnm2png basn3p04.ppm basn3p04.png
@@ -28,7 +28,7 @@
 # -- full-color
 ./pnm2png rawn2c08.ppm rawn2c08.png
 ./pnm2png rawn2c16.ppm rawn2c16.png
-# -- palletted
+# -- paletted
 ./pnm2png rawn3p01.ppm rawn3p01.png
 ./pnm2png rawn3p02.ppm rawn3p02.png
 ./pnm2png rawn3p04.ppm rawn3p04.png

contrib/pngsuite/README

@@ -16,6 +16,8 @@ chunks, etc.
 The "ft*.png" images are "free/libre" replacements for the transparent
 corresponding t*.png images in the PngSuite.
 
+The "i*.png" images are the same images, but interlaced.
+
 The images in this directory represent the basic PNG color-types:
 grayscale (1-16 bit deep), full color (8 or 16 bit), paletted
 (1-8 bit) and grayscale or color images with alpha channel. You

contrib/pngsuite/bad_interlace_conversions.txt

@@ -0,0 +1,9 @@
+basn0g01.png
+basn0g02.png
+basn0g04.png
+basn3p01.png
+basn3p02.png
+basn3p04.png
+ftbbn0g01.png
+ftbbn0g02.png
+ftbbn0g04.png

contrib/pngsuite/interlaced/README

@@ -0,0 +1,2 @@
+
+These images fail the "pngimage-quick" and "pngimage-full" tests.

contrib/powerpc-vsx/README

@@ -0,0 +1,81 @@
+OPERATING SYSTEM SPECIFIC POWERPC DETECTION
+--------------------------------------------
+
+Detection of the ability to execute POWERPC on processor requires
+operating system support.  (The information is not available in user mode.)
+
+Currently only this feature is supported only for linux platform.
+
+HOW TO USE THIS
+---------------
+
+This directory contains C code fragments that can be included in powerpc/powerpc_init.c
+by setting the macro PNG_POWERPC_VSX_FILE to the file name in "" or <> at build
+time.  This setting is not recorded in pnglibconf.h and can be changed simply by
+rebuilding arm/arm_init.o with the required macro definition.
+
+For any of this code to be used the POWERPC code must be enabled and run time
+checks must be supported.  I.e.:
+
+#if PNG_POWERPC_VSX_OPT > 0
+#ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED
+
+This is done in a 'configure' build by passing configure the argument:
+
+   --enable-powerpc-vsx=check
+
+FILE FORMAT
+-----------
+
+Each file documents its testing status as of the last time it was tested (which
+may have been a long time ago):
+
+STATUS: one of:
+   SUPPORTED: This indicates that the file is included in the regularly
+         performed test builds and bugs are fixed when discovered.
+   COMPILED: This indicates that the code did compile at least once.  See the
+         more detailed description for the extent to which the result was
+         successful.
+   TESTED: This means the code was fully compiled into the libpng test programs
+         and these were run at least once.
+
+BUG REPORTS: an email address to which to send reports of problems
+
+The file is a fragment of C code. It should not define any 'extern' symbols;
+everything should be static.  It must define the function:
+
+static int png_have_vsx(png_structp png_ptr);
+
+That function must return 1 if POWERPC_VSX instructions are supported, 0 if not.
+It must not execute png_error unless it detects a bug.  A png_error will prevent
+the reading of the PNG and in the future, writing too.
+
+BUG REPORTS
+-----------
+
+If you mail a bug report for any file that is not SUPPORTED there may only be
+limited response.  Consider fixing it and sending a patch to fix the problem -
+this is more likely to result in action.
+
+CONTRIBUTIONS
+-------------
+
+You may send contributions of new implementations to
+png-mng-implement@sourceforge.net.  Please write code in strict C90 C where
+possible.  Obviously OS dependencies are to be expected.  If you submit code you
+must have the authors permission and it must have a license that is acceptable
+to the current maintainer; in particular that license must permit modification
+and redistribution.
+
+Please try to make the contribution a single file and give the file a clear and
+unambiguous name that identifies the target OS.  If multiple files really are
+required put them all in a sub-directory.
+
+You must also be prepared to handle bug reports from users of the code, either
+by joining the png-mng-implement mailing list or by providing an email for the
+"BUG REPORTS" entry or both.  Please make sure that the header of the file
+contains the STATUS and BUG REPORTS fields as above.
+
+Please list the OS requirements as precisely as possible.  Ideally you should
+also list the environment in which the code has been tested and certainly list
+any environments where you suspect it might not work.

contrib/powerpc-vsx/linux.c

@@ -0,0 +1,57 @@
+/* contrib/powerpc-vsx/linux.c
+ *
+ * Copyright (c) 2017 Glenn Randers-Pehrson
+ * Written by Vadim Barkov, 2017.
+ * Last changed in libpng 1.6.29 [March 16, 2017]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * STATUS: TESTED
+ * BUG REPORTS: png-mng-implement@sourceforge.net
+ *
+ * png_have_vsx implemented for Linux by reading the widely available
+ * pseudo-file /proc/cpuinfo. 
+ *
+ * This code is strict ANSI-C and is probably moderately portable; it does
+ * however use <stdio.h> and it assumes that /proc/cpuinfo is never localized.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include "png.h"
+
+#ifndef MAXLINE
+#  define MAXLINE 1024
+#endif
+
+static int
+png_have_vsx(png_structp png_ptr)
+{
+   FILE *f;
+
+   const char *string = "altivec supported";
+   char input[MAXLINE];
+   char *token = NULL;
+
+   PNG_UNUSED(png_ptr)
+
+   f = fopen("/proc/cpuinfo", "r");
+   if (f != NULL)
+   {
+      memset(input,0,MAXLINE);
+      while(fgets(input,MAXLINE,f) != NULL)
+      {
+         token = strstr(input,string);
+         if(token != NULL)
+            return 1;
+      }
+   }
+#ifdef PNG_WARNINGS_SUPPORTED
+   else
+      png_warning(png_ptr, "/proc/cpuinfo open failed");
+#endif
+   return 0;
+}

contrib/powerpc-vsx/linux_aux.c

@@ -0,0 +1,34 @@
+/* contrib/powerpc-vsx/linux_aux.c
+ *
+ * Copyright (c) 2017 Glenn Randers-Pehrson
+ * Written by Vadim Barkov, 2017.
+ * Last changed in libpng 1.6.29 [March 16, 2017]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * STATUS: TESTED
+ * BUG REPORTS: png-mng-implement@sourceforge.net
+ *
+ * png_have_vsx implemented for Linux by using the auxiliary vector mechanism.
+ *
+ * This code is strict ANSI-C and is probably moderately portable; it does
+ * however use <stdio.h> and it assumes that /proc/cpuinfo is never localized.
+ */
+
+#include "sys/auxv.h"
+#include "png.h"
+
+static int
+png_have_vsx(png_structp png_ptr)
+{
+   unsigned long auxv = getauxval(AT_HWCAP);
+
+   PNG_UNUSED(png_ptr)
+
+   if(auxv & (PPC_FEATURE_HAS_ALTIVEC|PPC_FEATURE_HAS_VSX))
+      return 1;
+   else
+      return 0;
+}