Release libpng version 1.6.41

Many build scripts, ports and other third-party add-ons that are
circulating around appear to be distributed under the MIT License.
Examples include the Vcpkg build system (including the libpng port)
and the Meson build definitions (including the libpng definition).

I am, therefore, relicensing our CI scripts once more, as the sole
author (so far), just in case that any of the CI code might travel
from/to such projects. Hopefully, this one last license will stick.

Signed-off-by: Cosmin Truta <ctruta@gmail.com>

.appveyor.yml

@@ -0,0 +1,78 @@
+version: 1.6.x-{build}
+
+branches:
+  except:
+    - /libpng[0-1][0-7]/
+
+image:
+  - Visual Studio 2022
+
+shallow_clone: true
+
+environment:
+  matrix:
+    - TOOLCHAIN: vstudio
+      AUTOMATION: cmake
+      ARCH: x86
+    - TOOLCHAIN: vstudio
+      AUTOMATION: cmake
+      ARCH: x64
+    - TOOLCHAIN: vstudio
+      AUTOMATION: cmake
+      ARCH: arm64
+    - TOOLCHAIN: llvm
+      AUTOMATION: cmake
+      ARCH: x64
+    - TOOLCHAIN: msys2
+      AUTOMATION: cmake
+      ARCH: i686
+    - TOOLCHAIN: msys2
+      AUTOMATION: cmake
+      ARCH: x86_64
+    - TOOLCHAIN: msys2
+      AUTOMATION: configure
+      ARCH: i686
+    - TOOLCHAIN: msys2
+      AUTOMATION: configure
+      ARCH: x86_64
+    - TOOLCHAIN: msys2
+      AUTOMATION: makefiles
+      ARCH: i686
+    - TOOLCHAIN: msys2
+      AUTOMATION: makefiles
+      ARCH: x86_64
+
+install:
+  - 'if "%TOOLCHAIN%"=="vstudio" C:\tools\vcpkg\vcpkg.exe install zlib:%ARCH%-windows'
+  - 'if "%TOOLCHAIN%"=="vstudio" C:\tools\vcpkg\vcpkg.exe integrate install'
+  - 'if "%TOOLCHAIN%"=="llvm" C:\tools\vcpkg\vcpkg.exe install zlib:%ARCH%-windows'
+  - 'if "%TOOLCHAIN%"=="llvm" C:\tools\vcpkg\vcpkg.exe integrate install'
+
+before_build:
+  - 'if "%TOOLCHAIN%"=="vstudio" set CI_CMAKE_GENERATOR=Visual Studio 17 2022'
+  - 'if "%TOOLCHAIN%"=="vstudio" set CI_CMAKE_TOOLCHAIN_FILE=C:\tools\vcpkg\scripts\buildsystems\vcpkg.cmake'
+  - 'if "%TOOLCHAIN%"=="vstudio" if "%ARCH%"=="x86" set CI_CMAKE_GENERATOR_PLATFORM=Win32'
+  - 'if "%TOOLCHAIN%"=="vstudio" if "%ARCH%"=="x64" set CI_CMAKE_GENERATOR_PLATFORM=x64'
+  - 'if "%TOOLCHAIN%"=="vstudio" if "%ARCH%"=="arm64" set CI_CMAKE_GENERATOR_PLATFORM=ARM64'
+  - 'if "%TOOLCHAIN%"=="vstudio" if "%ARCH%"=="arm64" set CI_CMAKE_VARS=-DPNG_TESTS=0'
+  - 'if "%TOOLCHAIN%"=="llvm" set CI_CMAKE_GENERATOR=Ninja'
+  - 'if "%TOOLCHAIN%"=="llvm" set CI_CMAKE_TOOLCHAIN_FILE=C:\tools\vcpkg\scripts\buildsystems\vcpkg.cmake'
+  - 'if "%TOOLCHAIN%"=="llvm" set CI_CC=clang.exe'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%AUTOMATION%"=="cmake" set CI_CMAKE_GENERATOR=Unix Makefiles'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%ARCH%"=="i686" set PATH=C:\msys64\mingw32\bin;%PATH%'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%ARCH%"=="x86_64" set PATH=C:\msys64\mingw64\bin;%PATH%'
+  - 'if "%TOOLCHAIN%"=="msys2" set CI_CC=%ARCH%-w64-mingw32-gcc.exe'
+  - 'set CI_CMAKE_BUILD_FLAGS=-j2'
+  - 'set CI_CTEST_FLAGS=-j2'
+  - 'set CI_MAKE_FLAGS=-j2'
+  - 'set CI_MAKEFILES=scripts/makefile.gcc scripts/makefile.msys scripts/makefile.std'
+
+build_script:
+  - 'if "%TOOLCHAIN%"=="vstudio" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\ci\ci_verify_cmake.sh"'
+  - 'if "%TOOLCHAIN%"=="llvm" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\ci\ci_verify_cmake.sh"'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%AUTOMATION%"=="cmake" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\ci\ci_verify_cmake.sh"'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%AUTOMATION%"=="configure" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\ci\ci_verify_configure.sh"'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%AUTOMATION%"=="makefiles" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\ci\ci_verify_makefiles.sh"'
+
+cache:
+  - C:\tools\vcpkg\installed

.gitignore

@@ -0,0 +1,79 @@
+# Prerequisites
+*.d
+
+# Precompiled headers
+*.gch
+*.pch
+
+# Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Linker output files
+*.exp
+*.ilk
+*.map
+
+# Compiled dynamic libraries
+*.dll
+*.dylib
+*.so
+*.so.*
+
+# Compiled static libraries
+*.a
+*.la
+*.lai
+*.lib
+
+# Compiled executables
+*.app/
+*.exe
+
+# Debug files
+*.dSYM/
+*.idb
+*.pdb
+*.su
+
+# Libpng configuration and build artifacts
+*.out
+.deps/
+.dirstamp
+/Makefile
+/autom4te.cache/
+/config.guess~
+/config.h.in~
+/config.log
+/config.status
+/config.sub~
+/configure~
+/install-sh~
+/libpng-config
+/libpng.pc
+/libpng.vers
+/libpng16-config
+/libpng16.pc
+/libtool
+/stamp-h1
+pnglibconf.[ch]
+pnglibconf.dfn
+pnglibconf.pre
+pngprefix.h
+
+# Libpng test artifacts
+png-fix-itxt
+pngcp
+pngfix
+pngimage
+pngstest
+pngtest
+pngunknown
+pngvalid
+timepng
+pngout.png
+
+# Libpng CI artifacts
+out/

.travis.yml

@@ -0,0 +1,33 @@
+branches:
+  except:
+    - /libpng[0-1][0-7]/
+
+language: c
+
+os:
+  - freebsd
+  - linux
+  - osx
+
+env:
+  - AUTOMATION=cmake CI_CMAKE_VARS="-DPNG_HARDWARE_OPTIMIZATIONS=ON"
+  - AUTOMATION=cmake CI_CMAKE_VARS="-DPNG_HARDWARE_OPTIMIZATIONS=OFF"
+  - AUTOMATION=configure CI_CONFIGURE_FLAGS="--enable-hardware-optimizations"
+  - AUTOMATION=configure CI_CONFIGURE_FLAGS="--disable-hardware-optimizations"
+  - AUTOMATION=makefiles
+
+matrix:
+  include:
+    - os: osx
+      env: AUTOMATION=cmake CI_CMAKE_GENERATOR=Xcode
+
+before_script:
+  - 'if test "$TRAVIS_OS_NAME" = "linux"; then export CI_CC="gcc"; else export CI_CC="clang"; fi'
+  - 'if test "$TRAVIS_OS_NAME" != "osx"; then export CI_SANITIZERS="address,undefined"; fi'
+  - 'export CI_MAKEFILES="scripts/makefile.$CI_CC scripts/makefile.std"'
+  - 'export CI_MAKE_FLAGS=-j2'
+  - 'export CI_CMAKE_BUILD_FLAGS=-j2'
+  - 'export CI_CTEST_FLAGS=-j2'
+
+script:
+  - './ci/ci_verify_$AUTOMATION.sh'

.yamllint.yml

@@ -0,0 +1,5 @@
+extends: default
+rules:
+  document-start: disable
+  document-end: disable
+  line-length: disable

ANNOUNCE

@@ -1,48 +1,66 @@
-Libpng 1.6.35 - July 15, 2018
+libpng 1.6.41 - January 24, 2024
+================================
 
 This is a public release of libpng, intended for use in production code.
 
-Files available for download:
+
+Files available for download
+----------------------------
 
 Source files with LF line endings (for Unix/Linux):
 
-   libpng-1.6.35.tar.xz (LZMA-compressed, recommended)
-   libpng-1.6.35.tar.gz
+ * libpng-1.6.41.tar.xz (LZMA-compressed, recommended)
+ * libpng-1.6.41.tar.gz (deflate-compressed)
 
 Source files with CRLF line endings (for Windows):
 
-   lp1635.7z  (LZMA-compressed, recommended)
-   lp1635.zip
+ * lpng1641.7z (LZMA-compressed, recommended)
+ * lpng1641.zip (deflate-compressed)
 
 Other information:
 
-   libpng-1.6.35-README.txt
-   libpng-1.6.35-LICENSE.txt
+ * README.md
+ * LICENSE.md
+ * AUTHORS.md
+ * TRADEMARK.md
 
-Changes since the last public release (1.6.34):
 
-  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.
-  Make png_get_iCCP consistent with man page (allow compression-type argument
-    to be NULL, bug report by Lenard Szolnoki).
-  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)
+Changes from version 1.6.40 to version 1.6.41
+---------------------------------------------
 
-Send comments/corrections/commendations to png-mng-implement at lists.sf.net
-(subscription required; visit
+ * Added SIMD-optimized code for the Loongarch LSX hardware.
+   (Contributed by GuXiWei, JinBo and ZhangLixia)
+ * Fixed the run-time discovery of MIPS MSA hardware.
+   (Contributed by Sui Jingfeng)
+ * Fixed an off-by-one error in the function `png_do_check_palette_indexes`,
+   which failed to recognize errors that might have existed in the first
+   column of a broken palette-encoded image. This was a benign regression
+   accidentally introduced in libpng-1.6.33. No pixel was harmed.
+   (Contributed by Adam Richter; reviewed by John Bowler)
+ * Fixed, improved and modernized the contrib/pngminus programs, i.e.,
+   png2pnm.c and pnm2png.c
+ * Removed old and peculiar portability hacks that were meant to silence
+   warnings issued by gcc version 7.1 alone.
+   (Contributed by John Bowler)
+ * Fixed and modernized the CMake file, and raised the minimum required
+   CMake version from 3.1 to 3.6.
+   (Contributed by Clinton Ingram, Timothy Lyanguzov, Tyler Kropp, et al.)
+ * Allowed the configure script to disable the building of auxiliary tools
+   and tests, thus catching up with the CMake file.
+   (Contributed by Carlo Bramini)
+ * Fixed a build issue on Mac.
+   (Contributed by Zixu Wang)
+ * Moved the Autoconf macro files to scripts/autoconf.
+ * Moved the CMake files (except for the main CMakeLists.txt) to
+   scripts/cmake and moved the list of their contributing authors to
+   scripts/cmake/AUTHORS.md
+ * Updated the CI configurations and scripts.
+ * Relicensed the CI scripts to the MIT License.
+ * Improved the test coverage.
+   (Contributed by John Bowler)
+
+
+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).
-
-Glenn R-P
+to subscribe.

AUTHORS

@@ -0,0 +1,60 @@
+PNG REFERENCE LIBRARY AUTHORS
+=============================
+
+This is the list of PNG Reference Library ("libpng") Contributing
+Authors, for copyright and licensing purposes.
+
+ * Adam Richter
+ * 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
+ * Pascal Massimino
+ * Paul Schmidt
+ * Philippe Antoine
+ * Qiang Zhou
+ * Sam Bushell
+ * Samuel Williams
+ * Simon-Pierre Cadieux
+ * Tim Wegner
+ * Tom Lane
+ * Tom Tanner
+ * Vadim Barkov
+ * Willem van Schaik
+ * Zhijie Liang
+ * Apple Inc.
+    - Zixu Wang (王子旭)
+ * Arm Holdings
+    - Richard Townsend
+ * Google Inc.
+    - Dan Field
+    - Leon Scroggins III
+    - Matt Sarett
+    - Mike Klein
+    - Sami Boukortt
+    - Wan-Teh Chang
+ * Loongson Technology Corporation Ltd.
+    - GuXiWei (顾希伟)
+    - JinBo (金波)
+    - ZhangLixia (张利霞)
+
+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 "ci" and "contrib" directories, as well as some
+of the tools-generated files that are distributed with libpng, have
+other copyright owners, and are released under other open source
+licenses.

CHANGES

@@ -204,7 +204,7 @@ Version 0.97 [January, 1998]
   Added simple sRGB support (Glenn R-P)
   Easier conditional compiling, e.g.,
     define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
-    all configurable options can be selected from command-line instead
+    all configurable options can be selected from command line instead
     of having to edit pngconf.h (Glenn R-P)
   Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
   Added more conditions for png_do_background, to avoid changing
@@ -942,7 +942,7 @@ Version 1.0.8 [July 24, 2000]
 Version 1.0.9beta1 [November 10, 2000]
   Fixed typo in scripts/makefile.hpux
   Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
-  Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
+  Fixed sequence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
   Changed "cdrom.com" in documentation to "libpng.org"
   Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
   Changed type of "params" from voidp to png_voidp in png_read|write_png().
@@ -2295,7 +2295,7 @@ Version 1.4.0beta58 [May 14, 2009]
   Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)
 
 Version 1.4.0beta59 [May 15, 2009]
-  Reformated sources in libpng style (3-space intentation, comment format)
+  Reformatted sources in libpng style (3-space indentation, comment format)
   Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
   Added sections about the git repository and our coding style to the
     documentation
@@ -2661,7 +2661,7 @@ Version 1.4.1beta06 [January 28, 2010]
 
 Version 1.4.1beta07 [February 6, 2010]
   Folded some long lines in the source files.
-  Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
+  Added definable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
     and a PNG_USER_LIMITS_SUPPORTED flag.
   Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as
     png_ptr->png_user_chunk_malloc_max.
@@ -3886,7 +3886,7 @@ Version 1.6.0beta06 [January 24, 2012]
 Version 1.6.0beta07 [January 28, 2012]
   Eliminated Intel icc/icl compiler warnings. The Intel (GCC derived)
     compiler issues slightly different warnings from those issued by the
-    current vesions of GCC. This eliminates those warnings by
+    current versions of GCC. This eliminates those warnings by
     adding/removing casts and small code rewrites.
   Updated configure.ac from autoupdate: added --enable-werror option.
     Also some layout regularization and removal of introduced tab characters
@@ -3919,7 +3919,7 @@ Version 1.6.0beta08 [February 1, 2012]
     version checking to configure.ac
   Improved pngstest speed by not doing redundant tests and add const to
     the background parameter of png_image_finish_read. The --background
-    option is now done automagically only when required, so that commandline
+    option is now done automagically only when required, so that command-line
     option no longer exists.
   Cleaned up pngpriv.h to consistently declare all functions and data.
     Also eliminated PNG_CONST_DATA, which is apparently not needed but we
@@ -4052,7 +4052,7 @@ Version 1.6.0beta16 [March 6, 2012]
     (in fact this is harmless, but the PNG data produced may be sub-optimal).
 
 Version 1.6.0beta17 [March 10, 2012]
-  Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition. 
+  Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition.
   Reject all iCCP chunks after the first, even if the first one is invalid.
   Deflate/inflate was reworked to move common zlib calls into single
     functions [rw]util.c.  A new shared keyword check routine was also added
@@ -4962,7 +4962,7 @@ Version 1.6.13beta01 [July 4, 2014]
   Changed "if defined(__ARM_NEON__)" to
     "if (defined(__ARM_NEON__) || defined(__ARM_NEON))" (James Wu).
   Fixed clang no-warning builds: png_digit was defined but never used.
-    
+
 Version 1.6.13beta02 [July 21, 2014]
   Fixed an incorrect separator ("/" should be "\") in scripts/makefile.vcwin32
     (bug report from Wolfgang S. Kechel).  Bug was introduced in libpng-1.6.11.
@@ -5453,7 +5453,7 @@ Version 1.6.21beta01 [December 11, 2015]
 Version 1.6.21beta02 [December 14, 2015]
   Moved png_check_keyword() from pngwutil.c to pngset.c
   Removed LE/BE dependencies in pngvalid, to 'fix' the current problem
-    in the BigEndian tests by not testing it, making the BE code the same 
+    in the BigEndian tests by not testing it, making the BE code the same
     as the LE version.
   Fixes to pngvalid for various reduced build configurations (eliminate unused
     statics) and a fix for the case in rgb_to_gray when the digitize option
@@ -5517,7 +5517,7 @@ Version 1.6.22beta03 [March 9, 2016]
   Added a common-law trademark notice and export control information
     to the LICENSE file, png.h, and the man page.
   Restored "& 0xff" in png_save_uint_16() and png_save_uint_32() that
-    were accidentally removed from libpng-1.6.17. 
+    were accidentally removed from libpng-1.6.17.
   Changed PNG_INFO_cHNK and PNG_FREE_cHNK from 0xnnnn to 0xnnnnU in png.h
     (Robert C. Seacord).
   Removed dubious "#if INT_MAX" test from png.h that was added to
@@ -5927,7 +5927,7 @@ Version 1.6.32beta03 [August 2, 2017]
     (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().
+  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]
@@ -5950,7 +5950,7 @@ 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).
@@ -6063,9 +6063,105 @@ Version 1.6.35 [July 15, 2018]
   Added missing parentheses to a macro definition
     (suggested by "irwir" in GitHub issue #216)
 
-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).
+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.
 
-Glenn R-P
+Version 1.6.37 [April 14, 2019]
+  Fixed a use-after-free vulnerability (CVE-2019-7317) in png_image_free.
+  Fixed a memory leak in the ARM NEON implementation of png_do_expand_palette.
+  Fixed a memory leak in pngtest.c.
+  Fixed two vulnerabilities (CVE-2018-14048, CVE-2018-14550) in
+    contrib/pngminus; refactor.
+  Changed the license of contrib/pngminus to MIT; refresh makefile and docs.
+    (Contributed by Willem van Schaik)
+  Fixed a typo in the libpng license v2.
+    (Contributed by Miguel Ojeda)
+  Added makefiles for AddressSanitizer-enabled builds.
+  Cleaned up various makefiles.
+
+Version 1.6.38 [September 14, 2022]
+  Added configurations and scripts for continuous integration.
+  Fixed various errors in the handling of tRNS, hIST and eXIf.
+  Implemented many stability improvements across all platforms.
+  Updated the internal documentation.
+
+Version 1.6.39 [November 20, 2022]
+  Changed the error handler of oversized chunks (i.e. larger than
+    PNG_USER_CHUNK_MALLOC_MAX) from png_chunk_error to png_benign_error.
+  Fixed a buffer overflow error in contrib/tools/pngfix.
+  Fixed a memory leak (CVE-2019-6129) in contrib/tools/pngcp.
+  Disabled the ARM Neon optimizations by default in the CMake file,
+    following the default behavior of the configure script.
+  Allowed configure.ac to work with the trunk version of autoconf.
+  Removed the support for "install" targets from the legacy makefiles;
+    removed the obsolete makefile.cegcc.
+  Cleaned up the code and updated the internal documentation.
+
+Version 1.6.40 [June 21, 2023]
+  Fixed the eXIf chunk multiplicity checks.
+  Fixed a memory leak in pCAL processing.
+  Corrected the validity report about tRNS inside png_get_valid().
+  Fixed various build issues on *BSD, Mac and Windows.
+  Updated the configurations and the scripts for continuous integration.
+  Cleaned up the code, the build scripts, and the documentation.
+
+Version 1.6.41 [January 24, 2024]
+  Added SIMD-optimized code for the Loongarch LSX hardware.
+    (Contributed by GuXiWei, JinBo and ZhangLixia)
+  Fixed the run-time discovery of MIPS MSA hardware.
+    (Contributed by Sui Jingfeng)
+  Fixed an off-by-one error in the function `png_do_check_palette_indexes`,
+    which failed to recognize errors that might have existed in the first
+    column of a broken palette-encoded image. This was a benign regression
+    accidentally introduced in libpng-1.6.33. No pixel was harmed.
+    (Contributed by Adam Richter; reviewed by John Bowler)
+  Fixed, improved and modernized the contrib/pngminus programs, i.e.,
+    png2pnm.c and pnm2png.c
+  Removed old and peculiar portability hacks that were meant to silence
+    warnings issued by gcc version 7.1 alone.
+    (Contributed by John Bowler)
+  Fixed and modernized the CMake file, and raised the minimum required
+    CMake version from 3.1 to 3.6.
+    (Contributed by Clinton Ingram, Timothy Lyanguzov, Tyler Kropp, et al.)
+  Allowed the configure script to disable the building of auxiliary tools
+    and tests, thus catching up with the CMake file.
+    (Contributed by Carlo Bramini)
+  Fixed a build issue on Mac.
+    (Contributed by Zixu Wang)
+  Moved the Autoconf macro files to scripts/autoconf.
+  Moved the CMake files (except for the main CMakeLists.txt) to
+    scripts/cmake and moved the list of their contributing authors to
+    scripts/cmake/AUTHORS.md
+  Updated the CI configurations and scripts.
+  Relicensed the CI scripts to the MIT License.
+  Improved the test coverage.
+    (Contributed by John Bowler)
+
+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.

INSTALL

@@ -128,16 +128,18 @@ Your directory structure should look like this:
           README
           *.h, *.c  => libpng source files
           CMakeLists.txt    =>  "cmake" script
+          ci
+             ci_*.sh
           configuration files:
              configure.ac, configure, Makefile.am, Makefile.in,
              autogen.sh, config.guess, ltmain.sh, missing, libpng.pc.in,
              libpng-config.in, aclocal.m4, config.h.in, config.sub,
-             depcomp, install-sh, mkinstalldirs, test-pngtest.sh
+             depcomp, install-sh, mkinstalldirs, test-pngtest.sh, etc.
           contrib
              arm-neon, conftest, examples, gregbook, libtests, pngminim,
              pngminus, pngsuite, tools, visupng
           projects
-             cbuilder5, owatcom, visualc71, vstudio, xcode
+             owatcom, visualc71, vstudio
           scripts
              makefile.*
              *.def (module definition files)
@@ -145,7 +147,7 @@ Your directory structure should look like this:
           pngtest.png
           etc.
       zlib
-          README, *.h, *.c contrib, etc.
+          README, *.h, *.c, contrib, etc.
 
 If the line endings in the files look funny, you may wish to get the other
 distribution of libpng.  It is available in both tar.gz (UNIX style line
@@ -153,28 +155,27 @@ endings) and zip (DOS style line endings) formats.
 
 VI. Building with project files
 
-If you are building libpng with MSVC, you can enter the
-libpng projects\visualc71 or vstudio directory and follow the instructions
-in README.txt.
+If you are building libpng with Microsoft Visual Studio, you can enter
+the directory projects\visualc71 or projects\vstudio and follow the
+instructions in README.txt.
 
-Otherwise enter the zlib directory and follow the instructions in zlib/README,
-then come back here and run "configure" or choose the appropriate
-makefile.sys in the scripts directory.
+Otherwise, enter the zlib directory and follow the instructions in
+zlib/README, then come back here and run "configure" or choose the
+appropriate makefile in the scripts directory.
 
 VII. Building with makefiles
 
 Copy the file (or files) that you need from the
 scripts directory into this directory, for example
 
-MSDOS example:
-
-    copy scripts\makefile.msc makefile
-    copy scripts\pnglibconf.h.prebuilt pnglibconf.h
-
 UNIX example:
 
-    cp scripts/makefile.std makefile
-    cp scripts/pnglibconf.h.prebuilt pnglibconf.h
+    cp scripts/makefile.std Makefile
+    make
+
+Windows example:
+
+    nmake -f scripts\makefile.vcwin32
 
 Read the makefile to see if you need to change any source or
 target directories to match your preferences.
@@ -191,36 +192,33 @@ test.  For more confidence, you can run another test by typing
 Also, you can run "pngtest -m contrib/pngsuite/*.png" and compare
 your output with the result shown in contrib/pngsuite/README.
 
-Most of the makefiles will allow you to run "make install" to
-put the library in its final resting place (if you want to
-do that, run "make install" in the zlib directory first if necessary).
-Some also allow you to run "make test-installed" after you have
-run "make install".
+Most of the makefiles used to allow you to run "make install" to put
+the library in its final resting place, but that feature is no longer
+supported.  The only tested and supported manners to install libpng are
+the conventional build and install procedures driven by the configure
+script or by the CMake file.
 
-VIII. Configuring libpng for 16-bit platforms
+VIII. Configuring for DOS and other 16-bit platforms
 
-You will want to look into zconf.h to tell zlib (and thus libpng) that
-it cannot allocate more than 64K at a time.  Even if you can, the memory
-won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
-
-IX. Configuring for DOS
+Officially, the support for 16-bit platforms has been removed.
 
 For DOS users who only have access to the lower 640K, you will
 have to limit zlib's memory usage via a png_set_compression_mem_level()
 call.  See zlib.h or zconf.h in the zlib library for more information.
 
-X. Configuring for Medium Model
+You may be or may not be in luck if you target the "large" memory model,
+but all the smaller models ("small", "compact" and "medium") are known
+to be unworkable.  For DOS users who have access beyond the lower 640K,
+a "flat" 32-bit DOS model (such as DJGPP) is strongly recommended.
 
-Libpng's support for medium model has been tested on most of the popular
-compilers.  Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
-defined, and FAR gets defined to far in pngconf.h, and you should be
-all set.  Everything in the library (except for zlib's structure) is
-expecting far data.  You must use the typedefs with the p or pp on
-the end for pointers (or at least look at them and be careful).  Make
-note that the rows of data are defined as png_bytepp, which is
-an "unsigned char far * far *".
+For DOS users who only have access to the lower 640K, you will have to
+limit zlib's memory usage via a png_set_compression_mem_level() call.
+You will also have to look into zconf.h to tell zlib (and thus libpng)
+that it cannot allocate more than 64K at a time.  Even if you can, the
+memory won't be accessible.  Therefore, you should limit zlib and libpng
+to 64K by defining MAXSEG_64K.
 
-XI. Prepending a prefix to exported symbols
+IX. Prepending a prefix to exported symbols
 
 Starting with libpng-1.6.0, you can configure libpng (when using the
 "configure" script) to prefix all exported symbols by means of the
@@ -231,7 +229,7 @@ identifier).  This creates a set of macros in pnglibconf.h, so this is
 transparent to applications; their function calls get transformed by
 the macros to use the modified names.
 
-XII. Configuring for compiler xxx:
+X. Configuring for compiler xxx:
 
 All includes for libpng are in pngconf.h.  If you need to add, change
 or delete an include, this is the place to do it.
@@ -243,7 +241,7 @@ As of libpng-1.5.0, pngpriv.h also includes three other private header
 files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
 that previously appeared in the public headers.
 
-XIII. Removing unwanted object code
+XI. Removing unwanted object code
 
 There are a bunch of #define's in pngconf.h that control what parts of
 libpng are compiled.  All the defines end in _SUPPORTED.  If you are
@@ -282,7 +280,7 @@ 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. Enabling or disabling hardware optimizations
+XII. 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
@@ -332,7 +330,7 @@ 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
+XIII. 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
@@ -423,7 +421,7 @@ $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.
 
-XVI. Setjmp/longjmp issues
+XIV. 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
@@ -441,7 +439,7 @@ 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.
 
-XVII. Common linking failures
+XV. Common linking failures
 
 If your application fails to find libpng or zlib entries while linking:
 
@@ -453,12 +451,13 @@ 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.
 
-XVIII. Other sources of information about libpng:
+XVI. 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
 libpng.3 and png.5.
 
+Copyright (c) 2022 Cosmin Truta
 Copyright (c) 1998-2002,2006-2016 Glenn Randers-Pehrson
 This document is released under the libpng license.
 For conditions of distribution and use, see the disclaimer

LICENSE

@@ -1,53 +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) 1995-2024 The PNG Reference Library Authors.
+ * Copyright (c) 2018-2024 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 event 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 1.6.35, July 15, 2018 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
-   Mandar Sahastrabuddhe
-   Google Inc.
-   Vadim Barkov
+    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,
@@ -55,14 +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
@@ -71,63 +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
-July 15, 2018
+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) 2018-2024 Cosmin Truta
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
-# Last changed in libpng 1.6.25 [September 1, 2016]
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -9,16 +9,24 @@
 
 PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
 
-ACLOCAL_AMFLAGS = -I scripts
+ACLOCAL_AMFLAGS = -I scripts/autoconf
 
 # test programs - run on make check, make distcheck
+if ENABLE_TESTS
 check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage pngcp
 if HAVE_CLOCK_GETTIME
 check_PROGRAMS += timepng
 endif
+else
+check_PROGRAMS=
+endif
 
 # Utilities - installed
+if ENABLE_TOOLS
 bin_PROGRAMS= pngfix png-fix-itxt
+else
+bin_PROGRAMS=
+endif
 
 # This ensures that pnglibconf.h gets built at the start of 'make all' or
 # 'make check', but it does not add dependencies to the individual programs,
@@ -30,6 +38,7 @@ bin_PROGRAMS= pngfix png-fix-itxt
 # always wrong and always very confusing.
 BUILT_SOURCES = pnglibconf.h
 
+if ENABLE_TESTS
 pngtest_SOURCES = pngtest.c
 pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 
@@ -48,19 +57,22 @@ pngimage_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 timepng_SOURCES = contrib/libtests/timepng.c
 timepng_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 
+pngcp_SOURCES = contrib/tools/pngcp.c
+pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+endif
+
+if ENABLE_TOOLS
 pngfix_SOURCES = contrib/tools/pngfix.c
 pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 
 png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
-
-pngcp_SOURCES = contrib/tools/pngcp.c
-pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+endif
 
 # Generally these are single line shell scripts to run a test with a particular
 # set of parameters:
+if ENABLE_TESTS
 TESTS =\
-   tests/pngtest\
-   tests/pngtest-badpngs\
+   tests/pngtest-all\
    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\
@@ -76,6 +88,7 @@ TESTS =\
    tests/pngunknown-discard tests/pngunknown-if-safe tests/pngunknown-sAPI\
    tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg\
    tests/pngimage-quick tests/pngimage-full
+endif
 
 # man pages
 dist_man_MANS= libpng.3 libpngpf.3 png.5
@@ -95,7 +108,8 @@ 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
@@ -103,6 +117,13 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/mips_init.c\
 	mips/filter_msa_intrinsics.c
 endif
 
+if PNG_MIPS_MMI
+if !PNG_MIPS_MSA
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/mips_init.c
+endif
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/filter_mmi_inline_assembly.c
+endif
+
 if PNG_INTEL_SSE
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += intel/intel_init.c\
 	intel/filter_sse2_intrinsics.c
@@ -113,6 +134,15 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += powerpc/powerpc_init.c\
         powerpc/filter_vsx_intrinsics.c
 endif
 
+if PNG_LOONGARCH_LSX
+noinst_LTLIBRARIES= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_SOURCES = loongarch/loongarch_lsx_init.c\
+	loongarch/filter_lsx_intrinsics.c
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_CFLAGS = -mlsx
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+# libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+endif
+
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
 
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined -export-dynamic \
@@ -133,6 +163,10 @@ else
   libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.sym
 endif
 
+if PNG_LOONGARCH_LSX
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES += libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+endif
+
 #distribute headers in /usr/include/libpng/*
 pkgincludedir= $(includedir)/$(PNGLIB_BASENAME)
 pkginclude_HEADERS= png.h pngconf.h
@@ -147,9 +181,9 @@ 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 \
+	${srcdir}/ci ${srcdir}/contrib ${srcdir}/projects ${srcdir}/scripts \
 	$(TESTS) $(XFAIL_TESTS) tests/pngstest \
 	CMakeLists.txt example.c libpng-manual.txt
 

Makefile.in

@@ -1,7 +1,7 @@
-# Makefile.in generated by automake 1.16.1 from Makefile.am.
+# Makefile.in generated by automake 1.16.5 from Makefile.am.
 # @configure_input@
 
-# Copyright (C) 1994-2018 Free Software Foundation, Inc.
+# Copyright (C) 1994-2021 Free Software Foundation, Inc.
 
 # This Makefile.in is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -16,8 +16,8 @@
 
 # Makefile.am, the source file for Makefile.in (and hence Makefile), is
 #
+# Copyright (c) 2018-2024 Cosmin Truta
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
-# Last changed in libpng 1.6.25 [September 1, 2016]
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -100,37 +100,43 @@ PRE_UNINSTALL = :
 POST_UNINSTALL = :
 build_triplet = @build@
 host_triplet = @host@
-check_PROGRAMS = pngtest$(EXEEXT) pngunknown$(EXEEXT) \
-	pngstest$(EXEEXT) pngvalid$(EXEEXT) pngimage$(EXEEXT) \
-	pngcp$(EXEEXT) $(am__EXEEXT_1)
-@HAVE_CLOCK_GETTIME_TRUE@am__append_1 = timepng
-bin_PROGRAMS = pngfix$(EXEEXT) png-fix-itxt$(EXEEXT)
+@ENABLE_TESTS_TRUE@check_PROGRAMS = pngtest$(EXEEXT) \
+@ENABLE_TESTS_TRUE@	pngunknown$(EXEEXT) pngstest$(EXEEXT) \
+@ENABLE_TESTS_TRUE@	pngvalid$(EXEEXT) pngimage$(EXEEXT) \
+@ENABLE_TESTS_TRUE@	pngcp$(EXEEXT) $(am__EXEEXT_1)
+@ENABLE_TESTS_TRUE@@HAVE_CLOCK_GETTIME_TRUE@am__append_1 = timepng
+@ENABLE_TOOLS_TRUE@bin_PROGRAMS = pngfix$(EXEEXT) \
+@ENABLE_TOOLS_TRUE@	png-fix-itxt$(EXEEXT)
 @PNG_ARM_NEON_TRUE@am__append_2 = arm/arm_init.c\
-@PNG_ARM_NEON_TRUE@	arm/filter_neon.S arm/filter_neon_intrinsics.c
+@PNG_ARM_NEON_TRUE@	arm/filter_neon.S arm/filter_neon_intrinsics.c \
+@PNG_ARM_NEON_TRUE@	arm/palette_neon_intrinsics.c
 
 @PNG_MIPS_MSA_TRUE@am__append_3 = mips/mips_init.c\
 @PNG_MIPS_MSA_TRUE@	mips/filter_msa_intrinsics.c
 
-@PNG_INTEL_SSE_TRUE@am__append_4 = intel/intel_init.c\
+@PNG_MIPS_MMI_TRUE@@PNG_MIPS_MSA_FALSE@am__append_4 = mips/mips_init.c
+@PNG_MIPS_MMI_TRUE@am__append_5 = mips/filter_mmi_inline_assembly.c
+@PNG_INTEL_SSE_TRUE@am__append_6 = intel/intel_init.c\
 @PNG_INTEL_SSE_TRUE@	intel/filter_sse2_intrinsics.c
 
-@PNG_POWERPC_VSX_TRUE@am__append_5 = powerpc/powerpc_init.c\
+@PNG_POWERPC_VSX_TRUE@am__append_7 = powerpc/powerpc_init.c\
 @PNG_POWERPC_VSX_TRUE@        powerpc/filter_vsx_intrinsics.c
 
 
 #   Versioned symbols and restricted exports
-@HAVE_LD_VERSION_SCRIPT_TRUE@@HAVE_SOLARIS_LD_TRUE@am__append_6 = -Wl,-M -Wl,libpng.vers
-@HAVE_LD_VERSION_SCRIPT_TRUE@@HAVE_SOLARIS_LD_FALSE@am__append_7 = -Wl,--version-script=libpng.vers
+@HAVE_LD_VERSION_SCRIPT_TRUE@@HAVE_SOLARIS_LD_TRUE@am__append_8 = -Wl,-M -Wl,libpng.vers
+@HAVE_LD_VERSION_SCRIPT_TRUE@@HAVE_SOLARIS_LD_FALSE@am__append_9 = -Wl,--version-script=libpng.vers
 #   Only restricted exports when possible
-@HAVE_LD_VERSION_SCRIPT_FALSE@am__append_8 = -export-symbols libpng.sym
-@DO_PNG_PREFIX_TRUE@am__append_9 = -DPNG_PREFIX='@PNG_PREFIX@'
+@HAVE_LD_VERSION_SCRIPT_FALSE@am__append_10 = -export-symbols libpng.sym
+@PNG_LOONGARCH_LSX_TRUE@am__append_11 = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+@DO_PNG_PREFIX_TRUE@am__append_12 = -DPNG_PREFIX='@PNG_PREFIX@'
 subdir = .
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
-am__aclocal_m4_deps = $(top_srcdir)/scripts/libtool.m4 \
-	$(top_srcdir)/scripts/ltoptions.m4 \
-	$(top_srcdir)/scripts/ltsugar.m4 \
-	$(top_srcdir)/scripts/ltversion.m4 \
-	$(top_srcdir)/scripts/lt~obsolete.m4 \
+am__aclocal_m4_deps = $(top_srcdir)/scripts/autoconf/libtool.m4 \
+	$(top_srcdir)/scripts/autoconf/ltoptions.m4 \
+	$(top_srcdir)/scripts/autoconf/ltsugar.m4 \
+	$(top_srcdir)/scripts/autoconf/ltversion.m4 \
+	$(top_srcdir)/scripts/autoconf/lt~obsolete.m4 \
 	$(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
@@ -146,7 +152,8 @@ am__installdirs = "$(DESTDIR)$(bindir)" "$(DESTDIR)$(libdir)" \
 	"$(DESTDIR)$(bindir)" "$(DESTDIR)$(man3dir)" \
 	"$(DESTDIR)$(man5dir)" "$(DESTDIR)$(pkgconfigdir)" \
 	"$(DESTDIR)$(pkgincludedir)" "$(DESTDIR)$(pkgincludedir)"
-@HAVE_CLOCK_GETTIME_TRUE@am__EXEEXT_1 = timepng$(EXEEXT)
+@ENABLE_TESTS_TRUE@@HAVE_CLOCK_GETTIME_TRUE@am__EXEEXT_1 =  \
+@ENABLE_TESTS_TRUE@@HAVE_CLOCK_GETTIME_TRUE@	timepng$(EXEEXT)
 PROGRAMS = $(bin_PROGRAMS)
 am__vpath_adj_setup = srcdirstrip=`echo "$(srcdir)" | sed 's|.|.|g'`;
 am__vpath_adj = case $$p in \
@@ -175,31 +182,36 @@ am__uninstall_files_from_dir = { \
     || { echo " ( cd '$$dir' && rm -f" $$files ")"; \
          $(am__cd) "$$dir" && rm -f $$files; }; \
   }
-LTLIBRARIES = $(lib_LTLIBRARIES)
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD =
+LTLIBRARIES = $(lib_LTLIBRARIES) $(noinst_LTLIBRARIES)
 am__libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES_DIST = png.c \
 	pngerror.c pngget.c pngmem.c pngpread.c pngread.c pngrio.c \
 	pngrtran.c pngrutil.c pngset.c pngtrans.c pngwio.c pngwrite.c \
 	pngwtran.c pngwutil.c png.h pngconf.h pngdebug.h pnginfo.h \
 	pngpriv.h pngstruct.h pngusr.dfa arm/arm_init.c \
 	arm/filter_neon.S arm/filter_neon_intrinsics.c \
-	mips/mips_init.c mips/filter_msa_intrinsics.c \
+	arm/palette_neon_intrinsics.c mips/mips_init.c \
+	mips/filter_msa_intrinsics.c mips/filter_mmi_inline_assembly.c \
 	intel/intel_init.c intel/filter_sse2_intrinsics.c \
 	powerpc/powerpc_init.c powerpc/filter_vsx_intrinsics.c
 am__dirstamp = $(am__leading_dot)dirstamp
 @PNG_ARM_NEON_TRUE@am__objects_1 = arm/arm_init.lo arm/filter_neon.lo \
-@PNG_ARM_NEON_TRUE@	arm/filter_neon_intrinsics.lo
+@PNG_ARM_NEON_TRUE@	arm/filter_neon_intrinsics.lo \
+@PNG_ARM_NEON_TRUE@	arm/palette_neon_intrinsics.lo
 @PNG_MIPS_MSA_TRUE@am__objects_2 = mips/mips_init.lo \
 @PNG_MIPS_MSA_TRUE@	mips/filter_msa_intrinsics.lo
-@PNG_INTEL_SSE_TRUE@am__objects_3 = intel/intel_init.lo \
+@PNG_MIPS_MMI_TRUE@@PNG_MIPS_MSA_FALSE@am__objects_3 =  \
+@PNG_MIPS_MMI_TRUE@@PNG_MIPS_MSA_FALSE@	mips/mips_init.lo
+@PNG_MIPS_MMI_TRUE@am__objects_4 = mips/filter_mmi_inline_assembly.lo
+@PNG_INTEL_SSE_TRUE@am__objects_5 = intel/intel_init.lo \
 @PNG_INTEL_SSE_TRUE@	intel/filter_sse2_intrinsics.lo
-@PNG_POWERPC_VSX_TRUE@am__objects_4 = powerpc/powerpc_init.lo \
+@PNG_POWERPC_VSX_TRUE@am__objects_6 = powerpc/powerpc_init.lo \
 @PNG_POWERPC_VSX_TRUE@	powerpc/filter_vsx_intrinsics.lo
 am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS = png.lo pngerror.lo \
 	pngget.lo pngmem.lo pngpread.lo pngread.lo pngrio.lo \
 	pngrtran.lo pngrutil.lo pngset.lo pngtrans.lo pngwio.lo \
 	pngwrite.lo pngwtran.lo pngwutil.lo $(am__objects_1) \
-	$(am__objects_2) $(am__objects_3) $(am__objects_4)
+	$(am__objects_2) $(am__objects_3) $(am__objects_4) \
+	$(am__objects_5) $(am__objects_6)
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS =
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS =  \
 	$(am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS) \
@@ -213,33 +225,69 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LINK = $(LIBTOOL) $(AM_V_lt) \
 	$(CCLD) $(AM_CFLAGS) $(CFLAGS) \
 	$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS) $(LDFLAGS) -o \
 	$@
-am_png_fix_itxt_OBJECTS = contrib/tools/png-fix-itxt.$(OBJEXT)
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_LIBADD =
+am__libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_SOURCES_DIST =  \
+	loongarch/loongarch_lsx_init.c \
+	loongarch/filter_lsx_intrinsics.c
+@PNG_LOONGARCH_LSX_TRUE@am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_OBJECTS = loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.lo \
+@PNG_LOONGARCH_LSX_TRUE@	loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_OBJECTS =  \
+	$(am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_OBJECTS)
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_LINK = $(LIBTOOL) $(AM_V_lt) \
+	--tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=link \
+	$(CCLD) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_CFLAGS) \
+	$(CFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@
+@PNG_LOONGARCH_LSX_TRUE@am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_rpath =
+am__png_fix_itxt_SOURCES_DIST = contrib/tools/png-fix-itxt.c
+@ENABLE_TOOLS_TRUE@am_png_fix_itxt_OBJECTS =  \
+@ENABLE_TOOLS_TRUE@	contrib/tools/png-fix-itxt.$(OBJEXT)
 png_fix_itxt_OBJECTS = $(am_png_fix_itxt_OBJECTS)
 png_fix_itxt_LDADD = $(LDADD)
-am_pngcp_OBJECTS = contrib/tools/pngcp.$(OBJEXT)
+am__pngcp_SOURCES_DIST = contrib/tools/pngcp.c
+@ENABLE_TESTS_TRUE@am_pngcp_OBJECTS = contrib/tools/pngcp.$(OBJEXT)
 pngcp_OBJECTS = $(am_pngcp_OBJECTS)
-pngcp_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-am_pngfix_OBJECTS = contrib/tools/pngfix.$(OBJEXT)
+@ENABLE_TESTS_TRUE@pngcp_DEPENDENCIES =  \
+@ENABLE_TESTS_TRUE@	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+am__pngfix_SOURCES_DIST = contrib/tools/pngfix.c
+@ENABLE_TOOLS_TRUE@am_pngfix_OBJECTS = contrib/tools/pngfix.$(OBJEXT)
 pngfix_OBJECTS = $(am_pngfix_OBJECTS)
-pngfix_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-am_pngimage_OBJECTS = contrib/libtests/pngimage.$(OBJEXT)
+@ENABLE_TOOLS_TRUE@pngfix_DEPENDENCIES =  \
+@ENABLE_TOOLS_TRUE@	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+am__pngimage_SOURCES_DIST = contrib/libtests/pngimage.c
+@ENABLE_TESTS_TRUE@am_pngimage_OBJECTS =  \
+@ENABLE_TESTS_TRUE@	contrib/libtests/pngimage.$(OBJEXT)
 pngimage_OBJECTS = $(am_pngimage_OBJECTS)
-pngimage_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-am_pngstest_OBJECTS = contrib/libtests/pngstest.$(OBJEXT)
+@ENABLE_TESTS_TRUE@pngimage_DEPENDENCIES =  \
+@ENABLE_TESTS_TRUE@	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+am__pngstest_SOURCES_DIST = contrib/libtests/pngstest.c
+@ENABLE_TESTS_TRUE@am_pngstest_OBJECTS =  \
+@ENABLE_TESTS_TRUE@	contrib/libtests/pngstest.$(OBJEXT)
 pngstest_OBJECTS = $(am_pngstest_OBJECTS)
-pngstest_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-am_pngtest_OBJECTS = pngtest.$(OBJEXT)
+@ENABLE_TESTS_TRUE@pngstest_DEPENDENCIES =  \
+@ENABLE_TESTS_TRUE@	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+am__pngtest_SOURCES_DIST = pngtest.c
+@ENABLE_TESTS_TRUE@am_pngtest_OBJECTS = pngtest.$(OBJEXT)
 pngtest_OBJECTS = $(am_pngtest_OBJECTS)
-pngtest_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-am_pngunknown_OBJECTS = contrib/libtests/pngunknown.$(OBJEXT)
+@ENABLE_TESTS_TRUE@pngtest_DEPENDENCIES =  \
+@ENABLE_TESTS_TRUE@	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+am__pngunknown_SOURCES_DIST = contrib/libtests/pngunknown.c
+@ENABLE_TESTS_TRUE@am_pngunknown_OBJECTS =  \
+@ENABLE_TESTS_TRUE@	contrib/libtests/pngunknown.$(OBJEXT)
 pngunknown_OBJECTS = $(am_pngunknown_OBJECTS)
-pngunknown_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-am_pngvalid_OBJECTS = contrib/libtests/pngvalid.$(OBJEXT)
+@ENABLE_TESTS_TRUE@pngunknown_DEPENDENCIES =  \
+@ENABLE_TESTS_TRUE@	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+am__pngvalid_SOURCES_DIST = contrib/libtests/pngvalid.c
+@ENABLE_TESTS_TRUE@am_pngvalid_OBJECTS =  \
+@ENABLE_TESTS_TRUE@	contrib/libtests/pngvalid.$(OBJEXT)
 pngvalid_OBJECTS = $(am_pngvalid_OBJECTS)
-pngvalid_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-am_timepng_OBJECTS = contrib/libtests/timepng.$(OBJEXT)
+@ENABLE_TESTS_TRUE@pngvalid_DEPENDENCIES =  \
+@ENABLE_TESTS_TRUE@	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+am__timepng_SOURCES_DIST = contrib/libtests/timepng.c
+@ENABLE_TESTS_TRUE@am_timepng_OBJECTS =  \
+@ENABLE_TESTS_TRUE@	contrib/libtests/timepng.$(OBJEXT)
 timepng_OBJECTS = $(am_timepng_OBJECTS)
-timepng_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TESTS_TRUE@timepng_DEPENDENCIES =  \
+@ENABLE_TESTS_TRUE@	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 SCRIPTS = $(bin_SCRIPTS)
 AM_V_P = $(am__v_P_@AM_V@)
 am__v_P_ = $(am__v_P_@AM_DEFAULT_V@)
@@ -266,6 +314,7 @@ am__depfiles_remade = ./$(DEPDIR)/png.Plo ./$(DEPDIR)/pngerror.Plo \
 	./$(DEPDIR)/pngwtran.Plo ./$(DEPDIR)/pngwutil.Plo \
 	arm/$(DEPDIR)/arm_init.Plo arm/$(DEPDIR)/filter_neon.Plo \
 	arm/$(DEPDIR)/filter_neon_intrinsics.Plo \
+	arm/$(DEPDIR)/palette_neon_intrinsics.Plo \
 	contrib/libtests/$(DEPDIR)/pngimage.Po \
 	contrib/libtests/$(DEPDIR)/pngstest.Po \
 	contrib/libtests/$(DEPDIR)/pngunknown.Po \
@@ -276,6 +325,9 @@ am__depfiles_remade = ./$(DEPDIR)/png.Plo ./$(DEPDIR)/pngerror.Plo \
 	contrib/tools/$(DEPDIR)/pngfix.Po \
 	intel/$(DEPDIR)/filter_sse2_intrinsics.Plo \
 	intel/$(DEPDIR)/intel_init.Plo \
+	loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.Plo \
+	loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.Plo \
+	mips/$(DEPDIR)/filter_mmi_inline_assembly.Plo \
 	mips/$(DEPDIR)/filter_msa_intrinsics.Plo \
 	mips/$(DEPDIR)/mips_init.Plo \
 	powerpc/$(DEPDIR)/filter_vsx_intrinsics.Plo \
@@ -311,14 +363,18 @@ am__v_CCLD_0 = @echo "  CCLD    " $@;
 am__v_CCLD_1 = 
 SOURCES = $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES) \
 	$(nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES) \
+	$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_SOURCES) \
 	$(png_fix_itxt_SOURCES) $(pngcp_SOURCES) $(pngfix_SOURCES) \
 	$(pngimage_SOURCES) $(pngstest_SOURCES) $(pngtest_SOURCES) \
 	$(pngunknown_SOURCES) $(pngvalid_SOURCES) $(timepng_SOURCES)
 DIST_SOURCES =  \
 	$(am__libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES_DIST) \
-	$(png_fix_itxt_SOURCES) $(pngcp_SOURCES) $(pngfix_SOURCES) \
-	$(pngimage_SOURCES) $(pngstest_SOURCES) $(pngtest_SOURCES) \
-	$(pngunknown_SOURCES) $(pngvalid_SOURCES) $(timepng_SOURCES)
+	$(am__libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_SOURCES_DIST) \
+	$(am__png_fix_itxt_SOURCES_DIST) $(am__pngcp_SOURCES_DIST) \
+	$(am__pngfix_SOURCES_DIST) $(am__pngimage_SOURCES_DIST) \
+	$(am__pngstest_SOURCES_DIST) $(am__pngtest_SOURCES_DIST) \
+	$(am__pngunknown_SOURCES_DIST) $(am__pngvalid_SOURCES_DIST) \
+	$(am__timepng_SOURCES_DIST)
 am__can_run_installinfo = \
   case $$AM_UPDATE_INFO_DIR in \
     n|no|NO) false;; \
@@ -330,8 +386,8 @@ NROFF = nroff
 MANS = $(dist_man_MANS)
 DATA = $(pkgconfig_DATA)
 HEADERS = $(nodist_pkginclude_HEADERS) $(pkginclude_HEADERS)
-am__tagged_files = $(HEADERS) $(SOURCES) $(TAGS_FILES) \
-	$(LISP)config.h.in
+am__tagged_files = $(HEADERS) $(SOURCES) $(TAGS_FILES) $(LISP) \
+	config.h.in
 # Read a list of newline-separated strings from the standard input,
 # and print each of them once, without duplicates.  Input order is
 # *not* preserved.
@@ -348,9 +404,6 @@ am__define_uniq_tagged_files = \
   unique=`for i in $$list; do \
     if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
   done | $(am__uniquify_input)`
-ETAGS = etags
-CTAGS = ctags
-CSCOPE = cscope
 AM_RECURSIVE_TARGETS = cscope check recheck
 am__tty_colors_dummy = \
   mgn= red= grn= lgn= blu= brg= std=; \
@@ -507,6 +560,7 @@ am__set_TESTS_bases = \
   bases='$(TEST_LOGS)'; \
   bases=`for i in $$bases; do echo $$i; done | sed 's/\.log$$//'`; \
   bases=`echo $$bases`
+AM_TESTSUITE_SUMMARY_HEADER = ' for $(PACKAGE_STRING)'
 RECHECK_LOGS = $(TEST_LOGS)
 TEST_SUITE_LOG = test-suite.log
 TEST_EXTENSIONS = @EXEEXT@ .test
@@ -530,7 +584,7 @@ TEST_LOG_COMPILE = $(TEST_LOG_COMPILER) $(AM_TEST_LOG_FLAGS) \
 	$(TEST_LOG_FLAGS)
 am__DIST_COMMON = $(dist_man_MANS) $(srcdir)/Makefile.in \
 	$(srcdir)/config.h.in $(srcdir)/libpng-config.in \
-	$(srcdir)/libpng.pc.in INSTALL README TODO compile \
+	$(srcdir)/libpng.pc.in AUTHORS INSTALL README TODO compile \
 	config.guess config.sub depcomp install-sh ltmain.sh missing \
 	test-driver
 DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
@@ -546,6 +600,8 @@ am__post_remove_distdir = $(am__remove_distdir)
 DIST_ARCHIVES = $(distdir).tar.gz $(distdir).tar.xz
 GZIP_ENV = --best
 DIST_TARGETS = dist-xz dist-gzip
+# Exists only to be overridden by the user if desired.
+AM_DISTCHECK_DVI_TARGET = dvi
 distuninstallcheck_listfiles = find . -type f -print
 am__distuninstallcheck_listfiles = $(distuninstallcheck_listfiles) \
   | sed 's|^\./|$(prefix)/|' | grep -v '$(infodir)/dir$$'
@@ -570,6 +626,8 @@ CCDEPMODE = @CCDEPMODE@
 CFLAGS = @CFLAGS@
 CPP = @CPP@
 CPPFLAGS = @CPPFLAGS@
+CSCOPE = @CSCOPE@
+CTAGS = @CTAGS@
 CYGPATH_W = @CYGPATH_W@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
@@ -587,8 +645,10 @@ ECHO_C = @ECHO_C@
 ECHO_N = @ECHO_N@
 ECHO_T = @ECHO_T@
 EGREP = @EGREP@
+ETAGS = @ETAGS@
 EXEEXT = @EXEEXT@
 FGREP = @FGREP@
+FILECMD = @FILECMD@
 GREP = @GREP@
 INSTALL = @INSTALL@
 INSTALL_DATA = @INSTALL_DATA@
@@ -632,7 +692,6 @@ PNGLIB_VERSION = @PNGLIB_VERSION@
 # AM_CFLAGS)
 PNG_COPTS = @PNG_COPTS@
 PNG_PREFIX = @PNG_PREFIX@
-POW_LIB = @POW_LIB@
 RANLIB = @RANLIB@
 SED = @SED@
 SET_MAKE = @SET_MAKE@
@@ -691,6 +750,7 @@ pkgconfigdir = @pkgconfigdir@
 prefix = @prefix@
 program_transform_name = @program_transform_name@
 psdir = @psdir@
+runstatedir = @runstatedir@
 sbindir = @sbindir@
 sharedstatedir = @sharedstatedir@
 srcdir = @srcdir@
@@ -700,7 +760,7 @@ top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 PNGLIB_BASENAME = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
-ACLOCAL_AMFLAGS = -I scripts
+ACLOCAL_AMFLAGS = -I scripts/autoconf
 
 # This ensures that pnglibconf.h gets built at the start of 'make all' or
 # 'make check', but it does not add dependencies to the individual programs,
@@ -711,44 +771,43 @@ ACLOCAL_AMFLAGS = -I scripts
 # result in the installed (system) pnglibconf.h being used and the result is
 # always wrong and always very confusing.
 BUILT_SOURCES = pnglibconf.h
-pngtest_SOURCES = pngtest.c
-pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-pngvalid_SOURCES = contrib/libtests/pngvalid.c
-pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-pngstest_SOURCES = contrib/libtests/pngstest.c
-pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-pngunknown_SOURCES = contrib/libtests/pngunknown.c
-pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-pngimage_SOURCES = contrib/libtests/pngimage.c
-pngimage_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-timepng_SOURCES = contrib/libtests/timepng.c
-timepng_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-pngfix_SOURCES = contrib/tools/pngfix.c
-pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
-pngcp_SOURCES = contrib/tools/pngcp.c
-pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TESTS_TRUE@pngtest_SOURCES = pngtest.c
+@ENABLE_TESTS_TRUE@pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TESTS_TRUE@pngvalid_SOURCES = contrib/libtests/pngvalid.c
+@ENABLE_TESTS_TRUE@pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TESTS_TRUE@pngstest_SOURCES = contrib/libtests/pngstest.c
+@ENABLE_TESTS_TRUE@pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TESTS_TRUE@pngunknown_SOURCES = contrib/libtests/pngunknown.c
+@ENABLE_TESTS_TRUE@pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TESTS_TRUE@pngimage_SOURCES = contrib/libtests/pngimage.c
+@ENABLE_TESTS_TRUE@pngimage_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TESTS_TRUE@timepng_SOURCES = contrib/libtests/timepng.c
+@ENABLE_TESTS_TRUE@timepng_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TESTS_TRUE@pngcp_SOURCES = contrib/tools/pngcp.c
+@ENABLE_TESTS_TRUE@pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TOOLS_TRUE@pngfix_SOURCES = contrib/tools/pngfix.c
+@ENABLE_TOOLS_TRUE@pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+@ENABLE_TOOLS_TRUE@png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
 
 # Generally these are single line shell scripts to run a test with a particular
 # 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\
-   tests/pngvalid-gamma-expand16-transform tests/pngvalid-gamma-sbit\
-   tests/pngvalid-gamma-threshold tests/pngvalid-gamma-transform\
-   tests/pngvalid-progressive-size\
-   tests/pngvalid-progressive-interlace-standard\
-   tests/pngvalid-transform\
-   tests/pngvalid-progressive-standard tests/pngvalid-standard\
-   tests/pngstest-1.8 tests/pngstest-1.8-alpha tests/pngstest-linear\
-   tests/pngstest-linear-alpha tests/pngstest-none tests/pngstest-none-alpha\
-   tests/pngstest-sRGB tests/pngstest-sRGB-alpha tests/pngunknown-IDAT\
-   tests/pngunknown-discard tests/pngunknown-if-safe tests/pngunknown-sAPI\
-   tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg\
-   tests/pngimage-quick tests/pngimage-full
+@ENABLE_TESTS_TRUE@TESTS = \
+@ENABLE_TESTS_TRUE@   tests/pngtest-all\
+@ENABLE_TESTS_TRUE@   tests/pngvalid-gamma-16-to-8 tests/pngvalid-gamma-alpha-mode\
+@ENABLE_TESTS_TRUE@   tests/pngvalid-gamma-background tests/pngvalid-gamma-expand16-alpha-mode\
+@ENABLE_TESTS_TRUE@   tests/pngvalid-gamma-expand16-background\
+@ENABLE_TESTS_TRUE@   tests/pngvalid-gamma-expand16-transform tests/pngvalid-gamma-sbit\
+@ENABLE_TESTS_TRUE@   tests/pngvalid-gamma-threshold tests/pngvalid-gamma-transform\
+@ENABLE_TESTS_TRUE@   tests/pngvalid-progressive-size\
+@ENABLE_TESTS_TRUE@   tests/pngvalid-progressive-interlace-standard\
+@ENABLE_TESTS_TRUE@   tests/pngvalid-transform\
+@ENABLE_TESTS_TRUE@   tests/pngvalid-progressive-standard tests/pngvalid-standard\
+@ENABLE_TESTS_TRUE@   tests/pngstest-1.8 tests/pngstest-1.8-alpha tests/pngstest-linear\
+@ENABLE_TESTS_TRUE@   tests/pngstest-linear-alpha tests/pngstest-none tests/pngstest-none-alpha\
+@ENABLE_TESTS_TRUE@   tests/pngstest-sRGB tests/pngstest-sRGB-alpha tests/pngunknown-IDAT\
+@ENABLE_TESTS_TRUE@   tests/pngunknown-discard tests/pngunknown-if-safe tests/pngunknown-sAPI\
+@ENABLE_TESTS_TRUE@   tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg\
+@ENABLE_TESTS_TRUE@   tests/pngimage-quick tests/pngimage-full
 
 
 # man pages
@@ -764,14 +823,24 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c \
 	pngrutil.c pngset.c pngtrans.c pngwio.c pngwrite.c pngwtran.c \
 	pngwutil.c png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h \
 	pngstruct.h pngusr.dfa $(am__append_2) $(am__append_3) \
-	$(am__append_4) $(am__append_5)
+	$(am__append_4) $(am__append_5) $(am__append_6) \
+	$(am__append_7)
+@PNG_LOONGARCH_LSX_TRUE@noinst_LTLIBRARIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+@PNG_LOONGARCH_LSX_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_SOURCES = loongarch/loongarch_lsx_init.c\
+@PNG_LOONGARCH_LSX_TRUE@	loongarch/filter_lsx_intrinsics.c
+
+@PNG_LOONGARCH_LSX_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_CFLAGS = -mlsx
+@PNG_LOONGARCH_LSX_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+# libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
 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 \
-	$(am__append_6) $(am__append_7) $(am__append_8)
-@HAVE_LD_VERSION_SCRIPT_FALSE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.sym
-@HAVE_LD_VERSION_SCRIPT_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.vers
+	$(am__append_8) $(am__append_9) $(am__append_10)
+@HAVE_LD_VERSION_SCRIPT_FALSE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES =  \
+@HAVE_LD_VERSION_SCRIPT_FALSE@	libpng.sym $(am__append_11)
+@HAVE_LD_VERSION_SCRIPT_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES =  \
+@HAVE_LD_VERSION_SCRIPT_TRUE@	libpng.vers $(am__append_11)
 pkginclude_HEADERS = png.h pngconf.h
 nodist_pkginclude_HEADERS = pnglibconf.h
 pkgconfig_DATA = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc
@@ -780,9 +849,9 @@ 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 \
+	${srcdir}/ci ${srcdir}/contrib ${srcdir}/projects ${srcdir}/scripts \
 	$(TESTS) $(XFAIL_TESTS) tests/pngstest \
 	CMakeLists.txt example.c libpng-manual.txt
 
@@ -805,7 +874,7 @@ SUFFIXES = .chk .out
 SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0' \
 	-DPNGLIB_VERSION='@PNGLIB_VERSION@' \
 	-DSYMBOL_PREFIX='$(SYMBOL_PREFIX)' -DPNG_NO_USE_READ_MACROS \
-	-DPNG_BUILDING_SYMBOL_TABLE $(am__append_9)
+	-DPNG_BUILDING_SYMBOL_TABLE $(am__append_12)
 
 # EXT_LIST is a list of the possibly library directory extensions, this exists
 # because we can't find a good way of discovering the file extensions that are
@@ -962,6 +1031,17 @@ clean-libLTLIBRARIES:
 	  echo rm -f $${locs}; \
 	  rm -f $${locs}; \
 	}
+
+clean-noinstLTLIBRARIES:
+	-test -z "$(noinst_LTLIBRARIES)" || rm -f $(noinst_LTLIBRARIES)
+	@list='$(noinst_LTLIBRARIES)'; \
+	locs=`for p in $$list; do echo $$p; done | \
+	      sed 's|^[^/]*$$|.|; s|/[^/]*$$||; s|$$|/so_locations|' | \
+	      sort -u`; \
+	test -z "$$locs" || { \
+	  echo rm -f $${locs}; \
+	  rm -f $${locs}; \
+	}
 arm/$(am__dirstamp):
 	@$(MKDIR_P) arm
 	@: > arm/$(am__dirstamp)
@@ -972,6 +1052,8 @@ arm/arm_init.lo: arm/$(am__dirstamp) arm/$(DEPDIR)/$(am__dirstamp)
 arm/filter_neon.lo: arm/$(am__dirstamp) arm/$(DEPDIR)/$(am__dirstamp)
 arm/filter_neon_intrinsics.lo: arm/$(am__dirstamp) \
 	arm/$(DEPDIR)/$(am__dirstamp)
+arm/palette_neon_intrinsics.lo: arm/$(am__dirstamp) \
+	arm/$(DEPDIR)/$(am__dirstamp)
 mips/$(am__dirstamp):
 	@$(MKDIR_P) mips
 	@: > mips/$(am__dirstamp)
@@ -981,6 +1063,8 @@ mips/$(DEPDIR)/$(am__dirstamp):
 mips/mips_init.lo: mips/$(am__dirstamp) mips/$(DEPDIR)/$(am__dirstamp)
 mips/filter_msa_intrinsics.lo: mips/$(am__dirstamp) \
 	mips/$(DEPDIR)/$(am__dirstamp)
+mips/filter_mmi_inline_assembly.lo: mips/$(am__dirstamp) \
+	mips/$(DEPDIR)/$(am__dirstamp)
 intel/$(am__dirstamp):
 	@$(MKDIR_P) intel
 	@: > intel/$(am__dirstamp)
@@ -1004,6 +1088,19 @@ powerpc/filter_vsx_intrinsics.lo: powerpc/$(am__dirstamp) \
 
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la: $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES) $(EXTRA_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES) 
 	$(AM_V_CCLD)$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LINK) -rpath $(libdir) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD) $(LIBS)
+loongarch/$(am__dirstamp):
+	@$(MKDIR_P) loongarch
+	@: > loongarch/$(am__dirstamp)
+loongarch/$(DEPDIR)/$(am__dirstamp):
+	@$(MKDIR_P) loongarch/$(DEPDIR)
+	@: > loongarch/$(DEPDIR)/$(am__dirstamp)
+loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.lo:  \
+	loongarch/$(am__dirstamp) loongarch/$(DEPDIR)/$(am__dirstamp)
+loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo:  \
+	loongarch/$(am__dirstamp) loongarch/$(DEPDIR)/$(am__dirstamp)
+
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la: $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_OBJECTS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_DEPENDENCIES) $(EXTRA_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_DEPENDENCIES) 
+	$(AM_V_CCLD)$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_LINK) $(am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_rpath) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_OBJECTS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_LIBADD) $(LIBS)
 contrib/tools/$(am__dirstamp):
 	@$(MKDIR_P) contrib/tools
 	@: > contrib/tools/$(am__dirstamp)
@@ -1113,6 +1210,8 @@ mostlyclean-compile:
 	-rm -f contrib/tools/*.$(OBJEXT)
 	-rm -f intel/*.$(OBJEXT)
 	-rm -f intel/*.lo
+	-rm -f loongarch/*.$(OBJEXT)
+	-rm -f loongarch/*.lo
 	-rm -f mips/*.$(OBJEXT)
 	-rm -f mips/*.lo
 	-rm -f powerpc/*.$(OBJEXT)
@@ -1140,6 +1239,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@arm/$(DEPDIR)/arm_init.Plo@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@arm/$(DEPDIR)/filter_neon.Plo@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@arm/$(DEPDIR)/filter_neon_intrinsics.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@arm/$(DEPDIR)/palette_neon_intrinsics.Plo@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@contrib/libtests/$(DEPDIR)/pngimage.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@contrib/libtests/$(DEPDIR)/pngstest.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@contrib/libtests/$(DEPDIR)/pngunknown.Po@am__quote@ # am--include-marker
@@ -1150,6 +1250,9 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@contrib/tools/$(DEPDIR)/pngfix.Po@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@intel/$(DEPDIR)/filter_sse2_intrinsics.Plo@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@intel/$(DEPDIR)/intel_init.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@mips/$(DEPDIR)/filter_mmi_inline_assembly.Plo@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@mips/$(DEPDIR)/filter_msa_intrinsics.Plo@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@mips/$(DEPDIR)/mips_init.Plo@am__quote@ # am--include-marker
 @AMDEP_TRUE@@am__include@ @am__quote@powerpc/$(DEPDIR)/filter_vsx_intrinsics.Plo@am__quote@ # am--include-marker
@@ -1209,6 +1312,20 @@ am--depfiles: $(am__depfiles_remade)
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@	$(AM_V_CC@am__nodep@)$(LTCOMPILE) -c -o $@ $<
 
+loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.lo: loongarch/loongarch_lsx_init.c
+@am__fastdepCC_TRUE@	$(AM_V_CC)$(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_CFLAGS) $(CFLAGS) -MT loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.lo -MD -MP -MF loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.Tpo -c -o loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.lo `test -f 'loongarch/loongarch_lsx_init.c' || echo '$(srcdir)/'`loongarch/loongarch_lsx_init.c
+@am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.Tpo loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.Plo
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	$(AM_V_CC)source='loongarch/loongarch_lsx_init.c' object='loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.lo' libtool=yes @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(AM_V_CC@am__nodep@)$(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_CFLAGS) $(CFLAGS) -c -o loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.lo `test -f 'loongarch/loongarch_lsx_init.c' || echo '$(srcdir)/'`loongarch/loongarch_lsx_init.c
+
+loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo: loongarch/filter_lsx_intrinsics.c
+@am__fastdepCC_TRUE@	$(AM_V_CC)$(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_CFLAGS) $(CFLAGS) -MT loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo -MD -MP -MF loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.Tpo -c -o loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo `test -f 'loongarch/filter_lsx_intrinsics.c' || echo '$(srcdir)/'`loongarch/filter_lsx_intrinsics.c
+@am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.Tpo loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.Plo
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	$(AM_V_CC)source='loongarch/filter_lsx_intrinsics.c' object='loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo' libtool=yes @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(AM_V_CC@am__nodep@)$(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_CFLAGS) $(CFLAGS) -c -o loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo `test -f 'loongarch/filter_lsx_intrinsics.c' || echo '$(srcdir)/'`loongarch/filter_lsx_intrinsics.c
+
 mostlyclean-libtool:
 	-rm -f *.lo
 
@@ -1216,6 +1333,7 @@ clean-libtool:
 	-rm -rf .libs _libs
 	-rm -rf arm/.libs arm/_libs
 	-rm -rf intel/.libs intel/_libs
+	-rm -rf loongarch/.libs loongarch/_libs
 	-rm -rf mips/.libs mips/_libs
 	-rm -rf powerpc/.libs powerpc/_libs
 
@@ -1537,7 +1655,7 @@ $(TEST_SUITE_LOG): $(TEST_LOGS)
 	  test x"$$VERBOSE" = x || cat $(TEST_SUITE_LOG);		\
 	fi;								\
 	echo "$${col}$$br$${std}"; 					\
-	echo "$${col}Testsuite summary for $(PACKAGE_STRING)$${std}";	\
+	echo "$${col}Testsuite summary"$(AM_TESTSUITE_SUMMARY_HEADER)"$${std}";	\
 	echo "$${col}$$br$${std}"; 					\
 	create_testsuite_report --maybe-color;				\
 	echo "$$col$$br$$std";						\
@@ -1571,16 +1689,9 @@ recheck: all $(check_PROGRAMS)
 	        am__force_recheck=am--force-recheck \
 	        TEST_LOGS="$$log_list"; \
 	exit $$?
-tests/pngtest.log: tests/pngtest
-	@p='tests/pngtest'; \
-	b='tests/pngtest'; \
-	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
-	--log-file $$b.log --trs-file $$b.trs \
-	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
-	"$$tst" $(AM_TESTS_FD_REDIRECT)
-tests/pngtest-badpngs.log: tests/pngtest-badpngs
-	@p='tests/pngtest-badpngs'; \
-	b='tests/pngtest-badpngs'; \
+tests/pngtest-all.log: tests/pngtest-all
+	@p='tests/pngtest-all'; \
+	b='tests/pngtest-all'; \
 	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
 	--log-file $$b.log --trs-file $$b.trs \
 	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
@@ -1816,7 +1927,6 @@ tests/pngimage-full.log: tests/pngimage-full
 @am__EXEEXT_TRUE@	--log-file $$b.log --trs-file $$b.trs \
 @am__EXEEXT_TRUE@	$(am__common_driver_flags) $(AM_TEST_LOG_DRIVER_FLAGS) $(TEST_LOG_DRIVER_FLAGS) -- $(TEST_LOG_COMPILE) \
 @am__EXEEXT_TRUE@	"$$tst" $(AM_TESTS_FD_REDIRECT)
-
 distdir: $(BUILT_SOURCES)
 	$(MAKE) $(AM_MAKEFLAGS) distdir-am
 
@@ -1877,6 +1987,10 @@ dist-xz: distdir
 	tardir=$(distdir) && $(am__tar) | XZ_OPT=$${XZ_OPT--e} xz -c >$(distdir).tar.xz
 	$(am__post_remove_distdir)
 
+dist-zstd: distdir
+	tardir=$(distdir) && $(am__tar) | zstd -c $${ZSTD_CLEVEL-$${ZSTD_OPT--19}} >$(distdir).tar.zst
+	$(am__post_remove_distdir)
+
 dist-tarZ: distdir
 	@echo WARNING: "Support for distribution archives compressed with" \
 		       "legacy program 'compress' is deprecated." >&2
@@ -1919,6 +2033,8 @@ distcheck: dist
 	  eval GZIP= gzip $(GZIP_ENV) -dc $(distdir).shar.gz | unshar ;;\
 	*.zip*) \
 	  unzip $(distdir).zip ;;\
+	*.tar.zst*) \
+	  zstd -dc $(distdir).tar.zst | $(am__untar) ;;\
 	esac
 	chmod -R a-w $(distdir)
 	chmod u+w $(distdir)
@@ -1934,7 +2050,7 @@ distcheck: dist
 	    $(DISTCHECK_CONFIGURE_FLAGS) \
 	    --srcdir=../.. --prefix="$$dc_install_base" \
 	  && $(MAKE) $(AM_MAKEFLAGS) \
-	  && $(MAKE) $(AM_MAKEFLAGS) dvi \
+	  && $(MAKE) $(AM_MAKEFLAGS) $(AM_DISTCHECK_DVI_TARGET) \
 	  && $(MAKE) $(AM_MAKEFLAGS) check \
 	  && $(MAKE) $(AM_MAKEFLAGS) install \
 	  && $(MAKE) $(AM_MAKEFLAGS) installcheck \
@@ -1994,13 +2110,16 @@ all-am: Makefile $(PROGRAMS) $(LTLIBRARIES) $(SCRIPTS) $(MANS) $(DATA) \
 		$(HEADERS) config.h
 install-binPROGRAMS: install-libLTLIBRARIES
 
+install-checkPROGRAMS: install-libLTLIBRARIES
+
 installdirs:
 	for dir in "$(DESTDIR)$(bindir)" "$(DESTDIR)$(libdir)" "$(DESTDIR)$(bindir)" "$(DESTDIR)$(man3dir)" "$(DESTDIR)$(man5dir)" "$(DESTDIR)$(pkgconfigdir)" "$(DESTDIR)$(pkgincludedir)" "$(DESTDIR)$(pkgincludedir)"; do \
 	  test -z "$$dir" || $(MKDIR_P) "$$dir"; \
 	done
 install: $(BUILT_SOURCES)
 	$(MAKE) $(AM_MAKEFLAGS) install-am
-install-exec: install-exec-am
+install-exec: $(BUILT_SOURCES)
+	$(MAKE) $(AM_MAKEFLAGS) install-exec-am
 install-data: install-data-am
 uninstall: uninstall-am
 
@@ -2037,6 +2156,8 @@ distclean-generic:
 	-rm -f contrib/tools/$(am__dirstamp)
 	-rm -f intel/$(DEPDIR)/$(am__dirstamp)
 	-rm -f intel/$(am__dirstamp)
+	-rm -f loongarch/$(DEPDIR)/$(am__dirstamp)
+	-rm -f loongarch/$(am__dirstamp)
 	-rm -f mips/$(DEPDIR)/$(am__dirstamp)
 	-rm -f mips/$(am__dirstamp)
 	-rm -f powerpc/$(DEPDIR)/$(am__dirstamp)
@@ -2053,7 +2174,8 @@ maintainer-clean-generic:
 clean: clean-am
 
 clean-am: clean-binPROGRAMS clean-checkPROGRAMS clean-generic \
-	clean-libLTLIBRARIES clean-libtool mostlyclean-am
+	clean-libLTLIBRARIES clean-libtool clean-noinstLTLIBRARIES \
+	mostlyclean-am
 
 distclean: distclean-am
 	-rm -f $(am__CONFIG_DISTCLEAN_FILES)
@@ -2076,6 +2198,7 @@ distclean: distclean-am
 	-rm -f arm/$(DEPDIR)/arm_init.Plo
 	-rm -f arm/$(DEPDIR)/filter_neon.Plo
 	-rm -f arm/$(DEPDIR)/filter_neon_intrinsics.Plo
+	-rm -f arm/$(DEPDIR)/palette_neon_intrinsics.Plo
 	-rm -f contrib/libtests/$(DEPDIR)/pngimage.Po
 	-rm -f contrib/libtests/$(DEPDIR)/pngstest.Po
 	-rm -f contrib/libtests/$(DEPDIR)/pngunknown.Po
@@ -2086,6 +2209,9 @@ distclean: distclean-am
 	-rm -f contrib/tools/$(DEPDIR)/pngfix.Po
 	-rm -f intel/$(DEPDIR)/filter_sse2_intrinsics.Plo
 	-rm -f intel/$(DEPDIR)/intel_init.Plo
+	-rm -f loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.Plo
+	-rm -f loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.Plo
+	-rm -f mips/$(DEPDIR)/filter_mmi_inline_assembly.Plo
 	-rm -f mips/$(DEPDIR)/filter_msa_intrinsics.Plo
 	-rm -f mips/$(DEPDIR)/mips_init.Plo
 	-rm -f powerpc/$(DEPDIR)/filter_vsx_intrinsics.Plo
@@ -2160,6 +2286,7 @@ maintainer-clean: maintainer-clean-am
 	-rm -f arm/$(DEPDIR)/arm_init.Plo
 	-rm -f arm/$(DEPDIR)/filter_neon.Plo
 	-rm -f arm/$(DEPDIR)/filter_neon_intrinsics.Plo
+	-rm -f arm/$(DEPDIR)/palette_neon_intrinsics.Plo
 	-rm -f contrib/libtests/$(DEPDIR)/pngimage.Po
 	-rm -f contrib/libtests/$(DEPDIR)/pngstest.Po
 	-rm -f contrib/libtests/$(DEPDIR)/pngunknown.Po
@@ -2170,6 +2297,9 @@ maintainer-clean: maintainer-clean-am
 	-rm -f contrib/tools/$(DEPDIR)/pngfix.Po
 	-rm -f intel/$(DEPDIR)/filter_sse2_intrinsics.Plo
 	-rm -f intel/$(DEPDIR)/intel_init.Plo
+	-rm -f loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.Plo
+	-rm -f loongarch/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-loongarch_lsx_init.Plo
+	-rm -f mips/$(DEPDIR)/filter_mmi_inline_assembly.Plo
 	-rm -f mips/$(DEPDIR)/filter_msa_intrinsics.Plo
 	-rm -f mips/$(DEPDIR)/mips_init.Plo
 	-rm -f powerpc/$(DEPDIR)/filter_vsx_intrinsics.Plo
@@ -2199,21 +2329,22 @@ uninstall-am: uninstall-binPROGRAMS uninstall-binSCRIPTS \
 uninstall-man: uninstall-man3 uninstall-man5
 
 .MAKE: all check check-am install install-am install-data-am \
-	install-exec-am install-strip uninstall-am
+	install-exec install-exec-am install-strip uninstall-am
 
 .PHONY: CTAGS GTAGS TAGS all all-am am--depfiles am--refresh check \
 	check-TESTS check-am clean clean-binPROGRAMS \
 	clean-checkPROGRAMS clean-cscope clean-generic \
-	clean-libLTLIBRARIES clean-libtool cscope cscopelist-am ctags \
-	ctags-am dist dist-all dist-bzip2 dist-gzip dist-hook \
-	dist-lzip dist-shar dist-tarZ dist-xz dist-zip distcheck \
-	distclean distclean-compile distclean-generic distclean-hdr \
-	distclean-libtool distclean-tags distcleancheck distdir \
-	distuninstallcheck dvi dvi-am html html-am info info-am \
-	install install-am install-binPROGRAMS install-binSCRIPTS \
-	install-data install-data-am install-data-hook install-dvi \
-	install-dvi-am install-exec install-exec-am install-exec-hook \
-	install-html install-html-am install-info install-info-am \
+	clean-libLTLIBRARIES clean-libtool clean-noinstLTLIBRARIES \
+	cscope cscopelist-am ctags ctags-am dist dist-all dist-bzip2 \
+	dist-gzip dist-hook dist-lzip dist-shar dist-tarZ dist-xz \
+	dist-zip dist-zstd distcheck distclean distclean-compile \
+	distclean-generic distclean-hdr distclean-libtool \
+	distclean-tags distcleancheck distdir distuninstallcheck dvi \
+	dvi-am html html-am info info-am install install-am \
+	install-binPROGRAMS install-binSCRIPTS install-data \
+	install-data-am install-data-hook install-dvi install-dvi-am \
+	install-exec install-exec-am install-exec-hook install-html \
+	install-html-am install-info install-info-am \
 	install-libLTLIBRARIES install-man install-man3 install-man5 \
 	install-nodist_pkgincludeHEADERS install-pdf install-pdf-am \
 	install-pkgconfigDATA install-pkgincludeHEADERS install-ps \

README

@@ -1,56 +1,88 @@
-README for libpng version 1.6.35 - July 15, 2018 (shared library 16.0)
-See the note about version numbers near the top of png.h
+README for libpng version 1.6.41
+================================
 
-See INSTALL for instructions on how to install libpng.
+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 comes in several distribution formats.  Get `libpng-*.tar.gz`
+or `libpng-*.tar.xz` 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
-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
-March 1998.
+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`.
 
-****
-Note that some of the changes to the png_info structure render this
+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 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/pngdocs.html .
+
+This code is currently being archived at https://libpng.sourceforge.io
+in the download area, and at http://libpng.download/src .
+
+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 and commendations to `png-mng-implement`
+at `lists.sourceforge.net`.  (Subscription is required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe.)
+
+Send general questions about the PNG specification to `png-mng-misc`
+at `lists.sourceforge.net`.  (Subscription is required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-misc
+to subscribe.)
+
+Historical notes
+----------------
+
+The libpng library has been in extensive use and testing since mid-1995.
+Version 0.89, published a year later, was the first official release.
+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 below 1.0.  Version 1.0.0 was
+released in March 1998.
+
+Note that some of the changes to the `png_info` structure render this
 version of the library binary incompatible with libpng-0.89 or
 earlier versions if you are using a shared library.  The type of the
-"filler" parameter for png_set_filler() has changed from png_byte to
-png_uint_32, which will affect shared-library applications that use
-this function.
+`filler` parameter for `png_set_filler()` has changed from `png_byte`
+to `png_uint_32`, which will affect shared-library applications that
+use this function.
 
-To avoid problems with changes to the internals of the png info_struct,
+To avoid problems with changes to the internals of the `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
-accessing/storing the info_struct data, rather than manipulating it
+access to `info_ptr`.  These functions are the `png_set_<chunk>` and
+`png_get_<chunk>` functions.  These functions should be used when
+accessing/storing the `info_struct` data, rather than manipulating it
 directly, to avoid such problems in the future.
 
 It is important to note that the APIs did not make current programs
 that access the info struct directly incompatible with the new
 library, through libpng-1.2.x.  In libpng-1.4.x, which was meant to
-be a transitional release, members of the png_struct and the
-info_struct can still be accessed, but the compiler will issue a
+be a transitional release, members of the `png_struct` and the
+`info_struct` can still be accessed, but the compiler will issue a
 warning about deprecated usage.  Since libpng-1.5.0, direct access
 to these structs is not allowed, and the definitions of the structs
-reside in private pngstruct.h and pnginfo.h header files that are not
-accessible to applications.  It is strongly suggested that new
-programs use the new APIs (as shown in example.c and pngtest.c), and
-older programs be converted to the new format, to facilitate upgrades
-in the future.
-****
-
-Additions since 0.90 include the ability to compile libpng as a
-Windows DLL, and new APIs for accessing data in the info struct.
-Experimental functions include the ability to set weighting and cost
-factors for row filter selection, direct reads of integers from buffers
-on big-endian processors that support misaligned data access, faster
-methods of doing alpha composition, and more accurate 16->8 bit color
-conversion.
+reside in private `pngstruct.h` and `pnginfo.h` header files that are
+not accessible to applications.  It is strongly suggested that new
+programs use the new APIs (as shown in `example.c` and `pngtest.c`),
+and older programs be converted to the new format, to facilitate
+upgrades in the future.
 
 The additions since 0.89 include the ability to read from a PNG stream
 which has had some (or all) of the signature bytes read by the calling
@@ -60,163 +92,91 @@ 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.
+The additions since 0.90 include the ability to compile libpng as a
+Windows DLL, and new APIs for accessing data in the `info_struct`.
+Experimental functions included the ability to set weighting and cost
+factors for row filter selection, direct reads of integers from buffers
+on big-endian processors that support misaligned data access, faster
+methods of doing alpha composition, and more accurate 16-to-8 bit color
+conversion.  Some of these experimental functions, such as the weighted
+filter heuristics, have since been removed.
 
-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
+Files included in this distribution
+-----------------------------------
 
-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.
+    ANNOUNCE      =>  Announcement of this version, with recent changes
+    AUTHORS       =>  List of contributing authors
+    CHANGES       =>  Description of changes between libpng versions
+    INSTALL       =>  Instructions to install libpng
+    LICENSE       =>  License to use and redistribute libpng
+    README        =>  This file
+    TODO          =>  Things not implemented in the current library
+    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
+    libpngpf.3    =>  Manual page for libpng's private functions (deprecated)
+    png.5         =>  Manual page for the PNG format
+    png.c         =>  Basic interface functions common to library
+    png.h         =>  Library function and interface declarations (public)
+    pngpriv.h     =>  Library function and interface declarations (private)
+    pngconf.h     =>  System specific library configuration (public)
+    pngstruct.h   =>  png_struct declaration (private)
+    pnginfo.h     =>  png_info struct declaration (private)
+    pngdebug.h    =>  debugging macros (private)
+    pngerror.c    =>  Error/warning message I/O functions
+    pngget.c      =>  Functions for retrieving info from struct
+    pngmem.c      =>  Memory handling functions
+    pngbar.png    =>  PNG logo, 88x31
+    pngnow.png    =>  PNG logo, 98x31
+    pngpread.c    =>  Progressive reading functions
+    pngread.c     =>  Read data/helper high-level functions
+    pngrio.c      =>  Lowest-level data read I/O functions
+    pngrtran.c    =>  Read data transformation functions
+    pngrutil.c    =>  Read data utility functions
+    pngset.c      =>  Functions for storing data into the info_struct
+    pngtest.c     =>  Library test program
+    pngtest.png   =>  Library test sample image
+    pngtrans.c    =>  Common data transformation functions
+    pngwio.c      =>  Lowest-level write I/O functions
+    pngwrite.c    =>  High-level write functions
+    pngwtran.c    =>  Write data transformations
+    pngwutil.c    =>  Write utility functions
+    arm/          =>  Optimized code for the ARM platform
+    intel/        =>  Optimized code for the INTEL-SSE2 platform
+    mips/         =>  Optimized code for the MIPS platform
+    powerpc/      =>  Optimized code for the PowerPC platform
+    ci/           =>  Scripts for continuous integration
+    contrib/      =>  External contributions
+        arm-neon/     =>  Optimized code for the ARM-NEON platform
+        mips-msa/     =>  Optimized code for the MIPS-MSA platform
+        powerpc-vsx/  =>  Optimized code for the POWERPC-VSX platform
+        examples/     =>  Examples of libpng usage
+        gregbook/     =>  Source code for PNG reading and writing, from
+                          "PNG: The Definitive Guide" by Greg Roelofs,
+                          O'Reilly, 1999
+        libtests/     =>  Test programs
+        oss-fuzz/     =>  Files used by the OSS-Fuzz project for fuzz-testing
+                          libpng
+        pngminim/     =>  Minimal decoder, encoder, and progressive decoder
+                          programs demonstrating the use of pngusr.dfa
+        pngminus/     =>  Simple pnm2png and png2pnm programs
+        pngsuite/     =>  Test images
+        testpngs/     =>  Test images
+        tools/        =>  Various tools
+        visupng/      =>  VisualPng, a Windows viewer for PNG images
+    projects/     =>  Project files and workspaces for various IDEs
+        owatcom/      =>  OpenWatcom project
+        visualc71/    =>  Microsoft Visual C++ 7.1 workspace
+        vstudio/      =>  Microsoft Visual Studio workspace
+    scripts/      =>  Scripts and makefiles for building libpng
+                      (see scripts/README.txt for the complete list)
+    tests/        =>  Test scripts
 
-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.
+Good luck, and happy coding!
 
-zlib should be available at the same place that libpng is, or at 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/pngdocs.html .
-
-This code is currently being archived at libpng.sourceforge.io in the
-[DOWNLOAD] area, and at http://libpng.download/src .  If you
-can't find it in any of those places, e-mail me, and I'll help you find it.
-
-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
-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).
-
-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
-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.
-
-Files in this distribution:
-
-      ANNOUNCE      =>  Announcement of this version, with recent changes
-      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
-      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
-      libpngpf.3    =>  manual page for libpng's private functions
-      png.5         =>  manual page for the PNG format
-      png.c         =>  Basic interface functions common to library
-      png.h         =>  Library function and interface declarations (public)
-      pngpriv.h     =>  Library function and interface declarations (private)
-      pngconf.h     =>  System specific library configuration (public)
-      pngstruct.h   =>  png_struct declaration (private)
-      pnginfo.h     =>  png_info struct declaration (private)
-      pngdebug.h    =>  debugging macros (private)
-      pngerror.c    =>  Error/warning message I/O functions
-      pngget.c      =>  Functions for retrieving info from struct
-      pngmem.c      =>  Memory handling functions
-      pngbar.png    =>  PNG logo, 88x31
-      pngnow.png    =>  PNG logo, 98x31
-      pngpread.c    =>  Progressive reading functions
-      pngread.c     =>  Read data/helper high-level functions
-      pngrio.c      =>  Lowest-level data read I/O functions
-      pngrtran.c    =>  Read data transformation functions
-      pngrutil.c    =>  Read data utility functions
-      pngset.c      =>  Functions for storing data into the info_struct
-      pngtest.c     =>  Library test program
-      pngtest.png   =>  Library test sample image
-      pngtrans.c    =>  Common data transformation functions
-      pngwio.c      =>  Lowest-level write I/O functions
-      pngwrite.c    =>  High-level write functions
-      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
-       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
-       pngsuite         =>  Test images
-       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
-       visualc71        =>  Contains a Microsoft Visual C++ (MSVC)
-                            workspace for building libpng and zlib
-       vstudio          =>  Contains a Microsoft Visual C++ (MSVC)
-                            workspace for building libpng and zlib
-      scripts       =>  Directory containing scripts for building libpng:
-                            (see scripts/README.txt for the list of scripts)
-
-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.
-Extend pngvalid.c to validate more of the libpng transformations.
-Refactor preprocessor conditionals to compile entire statements
-
-*/
+* 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.

aclocal.m4

@@ -1,6 +1,6 @@
-# generated automatically by aclocal 1.16.1 -*- Autoconf -*-
+# generated automatically by aclocal 1.16.5 -*- Autoconf -*-
 
-# Copyright (C) 1996-2018 Free Software Foundation, Inc.
+# Copyright (C) 1996-2021 Free Software Foundation, Inc.
 
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -14,13 +14,13 @@
 m4_ifndef([AC_CONFIG_MACRO_DIRS], [m4_defun([_AM_CONFIG_MACRO_DIRS], [])m4_defun([AC_CONFIG_MACRO_DIRS], [_AM_CONFIG_MACRO_DIRS($@)])])
 m4_ifndef([AC_AUTOCONF_VERSION],
   [m4_copy([m4_PACKAGE_VERSION], [AC_AUTOCONF_VERSION])])dnl
-m4_if(m4_defn([AC_AUTOCONF_VERSION]), [2.69],,
-[m4_warning([this file was generated for autoconf 2.69.
+m4_if(m4_defn([AC_AUTOCONF_VERSION]), [2.72],,
+[m4_warning([this file was generated for autoconf 2.72.
 You have another version of autoconf.  It may work, but is not guaranteed to.
 If you have problems, you may need to regenerate the build system entirely.
 To do so, use the procedure documented by the package, typically 'autoreconf'.])])
 
-# Copyright (C) 2002-2018 Free Software Foundation, Inc.
+# Copyright (C) 2002-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -35,7 +35,7 @@ AC_DEFUN([AM_AUTOMAKE_VERSION],
 [am__api_version='1.16'
 dnl Some users find AM_AUTOMAKE_VERSION and mistake it for a way to
 dnl require some minimum version.  Point them to the right macro.
-m4_if([$1], [1.16.1], [],
+m4_if([$1], [1.16.5], [],
       [AC_FATAL([Do not call $0, use AM_INIT_AUTOMAKE([$1]).])])dnl
 ])
 
@@ -51,14 +51,14 @@ m4_define([_AM_AUTOCONF_VERSION], [])
 # Call AM_AUTOMAKE_VERSION and AM_AUTOMAKE_VERSION so they can be traced.
 # This function is AC_REQUIREd by AM_INIT_AUTOMAKE.
 AC_DEFUN([AM_SET_CURRENT_AUTOMAKE_VERSION],
-[AM_AUTOMAKE_VERSION([1.16.1])dnl
+[AM_AUTOMAKE_VERSION([1.16.5])dnl
 m4_ifndef([AC_AUTOCONF_VERSION],
   [m4_copy([m4_PACKAGE_VERSION], [AC_AUTOCONF_VERSION])])dnl
 _AM_AUTOCONF_VERSION(m4_defn([AC_AUTOCONF_VERSION]))])
 
 # Figure out how to run the assembler.                      -*- Autoconf -*-
 
-# Copyright (C) 2001-2018 Free Software Foundation, Inc.
+# Copyright (C) 2001-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -78,7 +78,7 @@ _AM_IF_OPTION([no-dependencies],, [_AM_DEPENDENCIES([CCAS])])dnl
 
 # AM_AUX_DIR_EXPAND                                         -*- Autoconf -*-
 
-# Copyright (C) 2001-2018 Free Software Foundation, Inc.
+# Copyright (C) 2001-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -130,7 +130,7 @@ am_aux_dir=`cd "$ac_aux_dir" && pwd`
 
 # AM_CONDITIONAL                                            -*- Autoconf -*-
 
-# Copyright (C) 1997-2018 Free Software Foundation, Inc.
+# Copyright (C) 1997-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -161,7 +161,7 @@ AC_CONFIG_COMMANDS_PRE(
 Usually this means the macro was only invoked conditionally.]])
 fi])])
 
-# Copyright (C) 1999-2018 Free Software Foundation, Inc.
+# Copyright (C) 1999-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -352,7 +352,7 @@ _AM_SUBST_NOTMAKE([am__nodep])dnl
 
 # Generate code to set up dependency tracking.              -*- Autoconf -*-
 
-# Copyright (C) 1999-2018 Free Software Foundation, Inc.
+# Copyright (C) 1999-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -391,7 +391,9 @@ AC_DEFUN([_AM_OUTPUT_DEPENDENCY_COMMANDS],
   done
   if test $am_rc -ne 0; then
     AC_MSG_FAILURE([Something went wrong bootstrapping makefile fragments
-    for automatic dependency tracking.  Try re-running configure with the
+    for automatic dependency tracking.  If GNU make was not used, consider
+    re-running the configure script with MAKE="gmake" (or whatever is
+    necessary).  You can also try re-running configure with the
     '--disable-dependency-tracking' option to at least be able to build
     the package (albeit without support for automatic dependency tracking).])
   fi
@@ -418,7 +420,7 @@ AC_DEFUN([AM_OUTPUT_DEPENDENCY_COMMANDS],
 
 # Do all the work for Automake.                             -*- Autoconf -*-
 
-# Copyright (C) 1996-2018 Free Software Foundation, Inc.
+# Copyright (C) 1996-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -446,6 +448,10 @@ m4_defn([AC_PROG_CC])
 # release and drop the old call support.
 AC_DEFUN([AM_INIT_AUTOMAKE],
 [AC_PREREQ([2.65])dnl
+m4_ifdef([_$0_ALREADY_INIT],
+  [m4_fatal([$0 expanded multiple times
+]m4_defn([_$0_ALREADY_INIT]))],
+  [m4_define([_$0_ALREADY_INIT], m4_expansion_stack)])dnl
 dnl Autoconf wants to disallow AM_ names.  We explicitly allow
 dnl the ones we care about.
 m4_pattern_allow([^AM_[A-Z]+FLAGS$])dnl
@@ -482,7 +488,7 @@ m4_ifval([$3], [_AM_SET_OPTION([no-define])])dnl
 [_AM_SET_OPTIONS([$1])dnl
 dnl Diagnose old-style AC_INIT with new-style AM_AUTOMAKE_INIT.
 m4_if(
-  m4_ifdef([AC_PACKAGE_NAME], [ok]):m4_ifdef([AC_PACKAGE_VERSION], [ok]),
+  m4_ifset([AC_PACKAGE_NAME], [ok]):m4_ifset([AC_PACKAGE_VERSION], [ok]),
   [ok:ok],,
   [m4_fatal([AC_INIT should be called with package and version arguments])])dnl
  AC_SUBST([PACKAGE], ['AC_PACKAGE_TARNAME'])dnl
@@ -534,6 +540,20 @@ AC_PROVIDE_IFELSE([AC_PROG_OBJCXX],
 		  [m4_define([AC_PROG_OBJCXX],
 			     m4_defn([AC_PROG_OBJCXX])[_AM_DEPENDENCIES([OBJCXX])])])dnl
 ])
+# Variables for tags utilities; see am/tags.am
+if test -z "$CTAGS"; then
+  CTAGS=ctags
+fi
+AC_SUBST([CTAGS])
+if test -z "$ETAGS"; then
+  ETAGS=etags
+fi
+AC_SUBST([ETAGS])
+if test -z "$CSCOPE"; then
+  CSCOPE=cscope
+fi
+AC_SUBST([CSCOPE])
+
 AC_REQUIRE([AM_SILENT_RULES])dnl
 dnl The testsuite driver may need to know about EXEEXT, so add the
 dnl 'am__EXEEXT' conditional if _AM_COMPILER_EXEEXT was seen.  This
@@ -615,7 +635,7 @@ for _am_header in $config_headers :; do
 done
 echo "timestamp for $_am_arg" >`AS_DIRNAME(["$_am_arg"])`/stamp-h[]$_am_stamp_count])
 
-# Copyright (C) 2001-2018 Free Software Foundation, Inc.
+# Copyright (C) 2001-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -636,7 +656,7 @@ if test x"${install_sh+set}" != xset; then
 fi
 AC_SUBST([install_sh])])
 
-# Copyright (C) 2003-2018 Free Software Foundation, Inc.
+# Copyright (C) 2003-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -658,7 +678,7 @@ AC_SUBST([am__leading_dot])])
 # Add --enable-maintainer-mode option to configure.         -*- Autoconf -*-
 # From Jim Meyering
 
-# Copyright (C) 1996-2018 Free Software Foundation, Inc.
+# Copyright (C) 1996-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -693,7 +713,7 @@ AC_MSG_CHECKING([whether to enable maintainer-specific portions of Makefiles])
 
 # Check to see how 'make' treats includes.	            -*- Autoconf -*-
 
-# Copyright (C) 2001-2018 Free Software Foundation, Inc.
+# Copyright (C) 2001-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -736,7 +756,7 @@ AC_SUBST([am__quote])])
 
 # Fake the existence of programs that GNU maintainers use.  -*- Autoconf -*-
 
-# Copyright (C) 1997-2018 Free Software Foundation, Inc.
+# Copyright (C) 1997-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -757,12 +777,7 @@ AC_DEFUN([AM_MISSING_HAS_RUN],
 [AC_REQUIRE([AM_AUX_DIR_EXPAND])dnl
 AC_REQUIRE_AUX_FILE([missing])dnl
 if test x"${MISSING+set}" != xset; then
-  case $am_aux_dir in
-  *\ * | *\	*)
-    MISSING="\${SHELL} \"$am_aux_dir/missing\"" ;;
-  *)
-    MISSING="\${SHELL} $am_aux_dir/missing" ;;
-  esac
+  MISSING="\${SHELL} '$am_aux_dir/missing'"
 fi
 # Use eval to expand $SHELL
 if eval "$MISSING --is-lightweight"; then
@@ -775,7 +790,7 @@ fi
 
 # Helper functions for option handling.                     -*- Autoconf -*-
 
-# Copyright (C) 2001-2018 Free Software Foundation, Inc.
+# Copyright (C) 2001-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -804,7 +819,7 @@ AC_DEFUN([_AM_SET_OPTIONS],
 AC_DEFUN([_AM_IF_OPTION],
 [m4_ifset(_AM_MANGLE_OPTION([$1]), [$2], [$3])])
 
-# Copyright (C) 1999-2018 Free Software Foundation, Inc.
+# Copyright (C) 1999-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -851,7 +866,7 @@ AC_LANG_POP([C])])
 # For backward compatibility.
 AC_DEFUN_ONCE([AM_PROG_CC_C_O], [AC_REQUIRE([AC_PROG_CC])])
 
-# Copyright (C) 2001-2018 Free Software Foundation, Inc.
+# Copyright (C) 2001-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -870,7 +885,7 @@ AC_DEFUN([AM_RUN_LOG],
 
 # Check to make sure that the build environment is sane.    -*- Autoconf -*-
 
-# Copyright (C) 1996-2018 Free Software Foundation, Inc.
+# Copyright (C) 1996-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -951,7 +966,7 @@ AC_CONFIG_COMMANDS_PRE(
 rm -f conftest.file
 ])
 
-# Copyright (C) 2009-2018 Free Software Foundation, Inc.
+# Copyright (C) 2009-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -1011,7 +1026,7 @@ AC_SUBST([AM_BACKSLASH])dnl
 _AM_SUBST_NOTMAKE([AM_BACKSLASH])dnl
 ])
 
-# Copyright (C) 2001-2018 Free Software Foundation, Inc.
+# Copyright (C) 2001-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -1039,7 +1054,7 @@ fi
 INSTALL_STRIP_PROGRAM="\$(install_sh) -c -s"
 AC_SUBST([INSTALL_STRIP_PROGRAM])])
 
-# Copyright (C) 2006-2018 Free Software Foundation, Inc.
+# Copyright (C) 2006-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -1058,7 +1073,7 @@ AC_DEFUN([AM_SUBST_NOTMAKE], [_AM_SUBST_NOTMAKE($@)])
 
 # Check how to create a tarball.                            -*- Autoconf -*-
 
-# Copyright (C) 2004-2018 Free Software Foundation, Inc.
+# Copyright (C) 2004-2021 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -1189,8 +1204,8 @@ AC_SUBST([am__tar])
 AC_SUBST([am__untar])
 ]) # _AM_PROG_TAR
 
-m4_include([scripts/libtool.m4])
-m4_include([scripts/ltoptions.m4])
-m4_include([scripts/ltsugar.m4])
-m4_include([scripts/ltversion.m4])
-m4_include([scripts/lt~obsolete.m4])
+m4_include([scripts/autoconf/libtool.m4])
+m4_include([scripts/autoconf/ltoptions.m4])
+m4_include([scripts/autoconf/ltsugar.m4])
+m4_include([scripts/autoconf/ltversion.m4])
+m4_include([scripts/autoconf/lt~obsolete.m4])

arm/arm_init.c

@@ -1,17 +1,16 @@
 
 /* arm_init.c - NEON optimised filter functions
  *
+ * Copyright (c) 2018-2022 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.
- */
+
+/* This module requires POSIX 1003.1 functions. */
 #define _POSIX_SOURCE 1
 
 #include "../pngpriv.h"
@@ -32,21 +31,26 @@
  * has partial support is contrib/arm-neon/linux.c - a generic Linux
  * implementation which reads /proc/cpufino.
  */
+#include <signal.h> /* for sig_atomic_t */
+
 #ifndef PNG_ARM_NEON_FILE
-#  ifdef __linux__
-#     define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
+#  if defined(__aarch64__) || defined(_M_ARM64)
+     /* ARM Neon is expected to be unconditionally available on ARM64. */
+#    error "PNG_ARM_NEON_CHECK_SUPPORTED must not be defined on ARM64"
+#  elif defined(__ARM_NEON__) || defined(__ARM_NEON)
+     /* ARM Neon is expected to be available on the target CPU architecture. */
+#    error "PNG_ARM_NEON_CHECK_SUPPORTED must not be defined on this CPU arch"
+#  elif defined(__linux__)
+#    define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
+#  else
+#    error "No support for run-time ARM Neon checking; use compile-time options"
 #  endif
 #endif
 
-#ifdef PNG_ARM_NEON_FILE
-
-#include <signal.h> /* for sig_atomic_t */
 static int png_have_neon(png_structp png_ptr);
-#include PNG_ARM_NEON_FILE
-
-#else  /* PNG_ARM_NEON_FILE */
-#  error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks"
-#endif /* PNG_ARM_NEON_FILE */
+#ifdef PNG_ARM_NEON_FILE
+#  include PNG_ARM_NEON_FILE
+#endif
 #endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
 
 #ifndef PNG_ALIGNED_MEMORY_SUPPORTED

arm/filter_neon.S

@@ -1,9 +1,9 @@
 
 /* filter_neon.S - NEON optimised filter functions
  *
+ * Copyright (c) 2018 Cosmin Truta
  * Copyright (c) 2014,2017 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.31 [July 27, 2017]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

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(__clang__) && 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 +1,151 @@
+
+/* palette_neon_intrinsics.c - NEON optimised palette expansion functions
+ *
+ * Copyright (c) 2018-2019 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(__clang__) && defined(_M_ARM64)
+#  include <arm64_neon.h>
+#else
+#  include <arm_neon.h>
+#endif
+
+/* Build an RGBA8 palette from the separate RGB and alpha palettes. */
+void
+png_riffle_palette_neon(png_structrp png_ptr)
+{
+   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),
+   }};
+
+   png_debug(1, "in png_riffle_palette_neon");
+
+   /* First, riffle the RGB colours into an RGBA8 palette.
+    * The alpha component is set to opaque for now.
+    */
+   for (i = 0; i < 256; 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 RGBA8. */
+int
+png_do_expand_palette_rgba8_neon(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_uint_32 pixels_per_chunk = 4;
+   png_uint_32 i;
+
+   png_debug(1, "in png_do_expand_palette_rgba8_neon");
+
+   PNG_UNUSED(row)
+   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 RGB8. */
+int
+png_do_expand_palette_rgb8_neon(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;
+   png_uint_32 i;
+
+   png_debug(1, "in png_do_expand_palette_rgb8_neon");
+
+   PNG_UNUSED(row)
+   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

@@ -77,13 +77,14 @@ libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in
    config.sub configure depcomp install-sh ltmain.sh missing\
    test-driver"
 #
-# Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
+# Files generated by versions of autoconf >2.68 or automake >1.13 (i.e. later
 # versions than those required by configure.ac):
 libpng_autotools_extra="compile config.h.in~"
 #
 # These are separate because 'maintainer-clean' does not remove them.
-libpng_libtool_files="scripts/libtool.m4 scripts/ltoptions.m4\
-   scripts/ltsugar.m4 scripts/ltversion.m4 scripts/lt~obsolete.m4"
+libpng_libtool_files="scripts/autoconf/libtool.m4 scripts/autoconf/ltoptions.m4\
+   scripts/autoconf/ltsugar.m4 scripts/autoconf/ltversion.m4\
+   scripts/autoconf/lt~obsolete.m4"
 
 libpng_autotools_dirs="autom4te.cache" # not required
 #

ci/.shellcheckrc

@@ -0,0 +1,11 @@
+# Disable the "variable appears unused" warning caused by the use of getopts
+# with an obligatory (but unused) variable name in the main function.
+disable=SC2034
+
+# Disable all the "quote to prevent globbing or word splitting" advice.
+# We need word splitting for well-known variables like MAKEFLAGS and CFLAGS.
+disable=SC2086,SC2206
+
+# Disable the "possible misspelling" warnings that might be flagged, e.g.,
+# inside function ci_trace_build.
+disable=SC2153

ci/LICENSE_MIT.txt

@@ -0,0 +1,19 @@
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

ci/ci_lint_ci.sh

@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+set -e
+
+# Copyright (c) 2019-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+# shellcheck source="ci/lib/ci.lib.sh"
+source "$(dirname "$0")/lib/ci.lib.sh"
+cd "$CI_TOPLEVEL_DIR"
+
+CI_SHELLCHECK="$(command -v shellcheck || true)"
+CI_YAMLLINT="$(command -v yamllint || true)"
+CI_LINT_COUNTER=0
+
+function ci_lint_ci_config_files {
+    ci_info "linting: CI config files"
+    local MY_FILE
+    if [[ -x $CI_YAMLLINT ]]
+    then
+        ci_spawn "$CI_YAMLLINT" --version
+        for MY_FILE in "$CI_TOPLEVEL_DIR"/.*.yml
+        do
+            ci_spawn "$CI_YAMLLINT" --strict "$MY_FILE" ||
+                CI_LINT_COUNTER=$((CI_LINT_COUNTER + 1))
+        done
+    else
+        ci_warn "program not found: 'yamllint'; skipping checks"
+    fi
+}
+
+function ci_lint_ci_scripts {
+    ci_info "linting: CI scripts"
+    local MY_FILE
+    if [[ -x $CI_SHELLCHECK ]]
+    then
+        ci_spawn "$CI_SHELLCHECK" --version
+        for MY_FILE in "$CI_SCRIPT_DIR"/*.sh
+        do
+            ci_spawn "$CI_SHELLCHECK" -x "$MY_FILE" ||
+                CI_LINT_COUNTER=$((CI_LINT_COUNTER + 1))
+        done
+    else
+        ci_warn "program not found: 'shellcheck'; skipping checks"
+    fi
+}
+
+function ci_lint_ci_scripts_license {
+    ci_info "linting: CI scripts license"
+    ci_spawn grep -F "MIT License" ci/LICENSE_MIT.txt || {
+        ci_warn "bad or missing CI license file: '$CI_SCRIPT_DIR/LICENSE_MIT.txt'"
+        CI_LINT_COUNTER=$((CI_LINT_COUNTER + 1))
+    }
+}
+
+function usage {
+    echo "usage: $CI_SCRIPT_NAME"
+    exit 0
+}
+
+function main {
+    local opt
+    while getopts ":" opt
+    do
+        # This ain't a while-loop. It only pretends to be.
+        [[ $1 == -[?h]* || $1 == --help ]] && usage
+        ci_err "unknown option: '$1'"
+    done
+    shift $((OPTIND - 1))
+    # And... go!
+    [[ $# -eq 0 ]] || ci_err "unexpected argument: '$1'"
+    ci_lint_ci_config_files
+    ci_lint_ci_scripts
+    ci_lint_ci_scripts_license
+    if [[ $CI_LINT_COUNTER -eq 0 ]]
+    then
+        ci_info "success!"
+        exit 0
+    else
+        ci_info "failed on $CI_LINT_COUNTER file(s)"
+        exit 1
+    fi
+}
+
+main "$@"

ci/ci_verify_cmake.sh

@@ -0,0 +1,194 @@
+#!/usr/bin/env bash
+set -e
+
+# Copyright (c) 2019-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+# shellcheck source="ci/lib/ci.lib.sh"
+source "$(dirname "$0")/lib/ci.lib.sh"
+cd "$CI_TOPLEVEL_DIR"
+
+CI_SRC_DIR="$CI_TOPLEVEL_DIR"
+CI_OUT_DIR="$CI_TOPLEVEL_DIR/out"
+CI_BUILD_DIR="$CI_OUT_DIR/ci_verify_cmake.$CI_TARGET_SYSTEM.$CI_TARGET_ARCH.build"
+CI_INSTALL_DIR="$CI_OUT_DIR/ci_verify_cmake.$CI_TARGET_SYSTEM.$CI_TARGET_ARCH.install"
+
+# Keep the following relative paths in sync with the absolute paths.
+# We use them for the benefit of native Windows tools that might be
+# otherwise confused by the path encoding used by Bash-on-Windows.
+CI_BUILD_TO_SRC_RELDIR="../.."
+CI_BUILD_TO_INSTALL_RELDIR="../ci_verify_cmake.$CI_TARGET_SYSTEM.$CI_TARGET_ARCH.install"
+
+function ci_init_build {
+    # Ensure that the mandatory variables are initialized.
+    CI_CMAKE="${CI_CMAKE:-cmake}"
+    CI_CTEST="${CI_CTEST:-ctest}"
+    CI_CMAKE_BUILD_TYPE="${CI_CMAKE_BUILD_TYPE:-Release}"
+    [[ -x $(command -v ninja) ]] &&
+        CI_CMAKE_GENERATOR="${CI_CMAKE_GENERATOR:-Ninja}"
+    if [[ $CI_CMAKE_GENERATOR == "Visual Studio"* ]]
+    then
+        # Clean up incidental mixtures of Windows and Bash-on-Windows
+        # environment variables, to avoid confusing MSBuild.
+        [[ $TEMP && ( $Temp || $temp ) ]] && unset TEMP
+        [[ $TMP && ( $Tmp || $tmp ) ]] && unset TMP
+        # Ensure that CI_CMAKE_GENERATOR_PLATFORM is initialized for this generator.
+        [[ $CI_CMAKE_GENERATOR_PLATFORM ]] ||
+            ci_err_internal "missing \$CI_CMAKE_GENERATOR_PLATFORM"
+    fi
+}
+
+function ci_trace_build {
+    ci_info "## START OF CONFIGURATION ##"
+    ci_info "build arch: $CI_BUILD_ARCH"
+    ci_info "build system: $CI_BUILD_SYSTEM"
+    [[ "$CI_TARGET_SYSTEM.$CI_TARGET_ARCH" != "$CI_BUILD_SYSTEM.$CI_BUILD_ARCH" ]] && {
+        ci_info "target arch: $CI_TARGET_ARCH"
+        ci_info "target system: $CI_TARGET_SYSTEM"
+    }
+    ci_info "source directory: $CI_SRC_DIR"
+    ci_info "build directory: $CI_BUILD_DIR"
+    ci_info "install directory: $CI_INSTALL_DIR"
+    ci_info "environment option: \$CI_CMAKE: '$CI_CMAKE'"
+    ci_info "environment option: \$CI_CMAKE_GENERATOR: '$CI_CMAKE_GENERATOR'"
+    ci_info "environment option: \$CI_CMAKE_GENERATOR_PLATFORM: '$CI_CMAKE_GENERATOR_PLATFORM'"
+    ci_info "environment option: \$CI_CMAKE_BUILD_TYPE: '$CI_CMAKE_BUILD_TYPE'"
+    ci_info "environment option: \$CI_CMAKE_BUILD_FLAGS: '$CI_CMAKE_BUILD_FLAGS'"
+    ci_info "environment option: \$CI_CMAKE_TOOLCHAIN_FILE: '$CI_CMAKE_TOOLCHAIN_FILE'"
+    ci_info "environment option: \$CI_CMAKE_VARS: '$CI_CMAKE_VARS'"
+    ci_info "environment option: \$CI_CTEST: '$CI_CTEST'"
+    ci_info "environment option: \$CI_CTEST_FLAGS: '$CI_CTEST_FLAGS'"
+    ci_info "environment option: \$CI_CC: '$CI_CC'"
+    ci_info "environment option: \$CI_CC_FLAGS: '$CI_CC_FLAGS'"
+    ci_info "environment option: \$CI_AR: '$CI_AR'"
+    ci_info "environment option: \$CI_RANLIB: '$CI_RANLIB'"
+    ci_info "environment option: \$CI_SANITIZERS: '$CI_SANITIZERS'"
+    ci_info "environment option: \$CI_NO_TEST: '$CI_NO_TEST'"
+    ci_info "environment option: \$CI_NO_INSTALL: '$CI_NO_INSTALL'"
+    ci_info "environment option: \$CI_NO_CLEAN: '$CI_NO_CLEAN'"
+    ci_info "executable: \$CI_CMAKE: $(command -V "$CI_CMAKE")"
+    ci_info "executable: \$CI_CTEST: $(command -V "$CI_CTEST")"
+    [[ $CI_CC ]] &&
+        ci_info "executable: \$CI_CC: $(command -V "$CI_CC")"
+    [[ $CI_AR ]] &&
+        ci_info "executable: \$CI_AR: $(command -V "$CI_AR")"
+    [[ $CI_RANLIB ]] &&
+        ci_info "executable: \$CI_RANLIB: $(command -V "$CI_RANLIB")"
+    ci_info "## END OF CONFIGURATION ##"
+}
+
+function ci_cleanup_old_build {
+    if [[ -e $CI_BUILD_DIR || -e $CI_INSTALL_DIR ]]
+    then
+        ci_info "## START OF PRE-BUILD CLEANUP ##"
+        ci_spawn rm -fr "$CI_BUILD_DIR"
+        ci_spawn rm -fr "$CI_INSTALL_DIR"
+        ci_info "## END OF PRE-BUILD CLEANUP ##"
+    fi
+}
+
+function ci_build {
+    ci_info "## START OF BUILD ##"
+    ci_spawn "$(command -v "$CI_CMAKE")" --version
+    ci_spawn "$(command -v "$CI_CTEST")" --version
+    [[ $CI_CMAKE_GENERATOR == *"Ninja"* ]] &&
+        ci_spawn "$(command -v ninja)" --version
+    # Initialize ALL_CC_FLAGS as a string.
+    local ALL_CC_FLAGS="$CI_CC_FLAGS"
+    [[ $CI_SANITIZERS ]] &&
+        ALL_CC_FLAGS="-fsanitize=$CI_SANITIZERS $ALL_CC_FLAGS"
+    # Initialize ALL_CMAKE_VARS, ALL_CMAKE_BUILD_FLAGS and ALL_CTEST_FLAGS as arrays.
+    local ALL_CMAKE_VARS=()
+    [[ $CI_CMAKE_TOOLCHAIN_FILE ]] &&
+        ALL_CMAKE_VARS+=(-DCMAKE_TOOLCHAIN_FILE="$CI_CMAKE_TOOLCHAIN_FILE")
+    [[ $CI_CC ]] &&
+        ALL_CMAKE_VARS+=(-DCMAKE_C_COMPILER="$CI_CC")
+    [[ $ALL_CC_FLAGS ]] &&
+        ALL_CMAKE_VARS+=(-DCMAKE_C_FLAGS="$ALL_CC_FLAGS")
+    [[ $CI_AR ]] && {
+        # Use the full path of CI_AR to work around a CMake error.
+        ALL_CMAKE_VARS+=(-DCMAKE_AR="$(command -v "$CI_AR")")
+    }
+    [[ $CI_RANLIB ]] && {
+        # Use the full path of CI_RANLIB to work around a CMake error.
+        ALL_CMAKE_VARS+=(-DCMAKE_RANLIB="$(command -v "$CI_RANLIB")")
+    }
+    ALL_CMAKE_VARS+=(-DCMAKE_BUILD_TYPE="$CI_CMAKE_BUILD_TYPE")
+    ALL_CMAKE_VARS+=(-DCMAKE_VERBOSE_MAKEFILE=ON)
+    ALL_CMAKE_VARS+=($CI_CMAKE_VARS)
+    local ALL_CMAKE_BUILD_FLAGS=($CI_CMAKE_BUILD_FLAGS)
+    local ALL_CTEST_FLAGS=($CI_CTEST_FLAGS)
+    # Export the CMake environment variables.
+    [[ $CI_CMAKE_GENERATOR ]] &&
+        ci_spawn export CMAKE_GENERATOR="$CI_CMAKE_GENERATOR"
+    [[ $CI_CMAKE_GENERATOR_PLATFORM ]] &&
+        ci_spawn export CMAKE_GENERATOR_PLATFORM="$CI_CMAKE_GENERATOR_PLATFORM"
+    # Build!
+    # Use $CI_BUILD_TO_SRC_RELDIR and $CI_BUILD_TO_INSTALL_RELDIR
+    # instead of $CI_SRC_DIR and $CI_INSTALL_DIR from this point onwards.
+    ci_spawn mkdir -p "$CI_BUILD_DIR"
+    ci_spawn cd "$CI_BUILD_DIR"
+    [[ $CI_BUILD_TO_SRC_RELDIR -ef $CI_SRC_DIR ]] ||
+        ci_err_internal "bad or missing \$CI_BUILD_TO_SRC_RELDIR"
+    ci_spawn mkdir -p "$CI_INSTALL_DIR"
+    [[ $CI_BUILD_TO_INSTALL_RELDIR -ef $CI_INSTALL_DIR ]] ||
+        ci_err_internal "bad or missing \$CI_BUILD_TO_INSTALL_RELDIR"
+    # Spawn "cmake ...".
+    ci_spawn "$CI_CMAKE" -DCMAKE_INSTALL_PREFIX="$CI_BUILD_TO_INSTALL_RELDIR" \
+                         "${ALL_CMAKE_VARS[@]}" \
+                         "$CI_BUILD_TO_SRC_RELDIR"
+    # Spawn "cmake --build ...".
+    ci_spawn "$CI_CMAKE" --build . \
+                         --config "$CI_CMAKE_BUILD_TYPE" \
+                         "${ALL_CMAKE_BUILD_FLAGS[@]}"
+    ci_expr $((CI_NO_TEST)) || {
+        # Spawn "ctest" if testing is not disabled.
+        ci_spawn "$CI_CTEST" --build-config "$CI_CMAKE_BUILD_TYPE" \
+                             "${ALL_CTEST_FLAGS[@]}"
+    }
+    ci_expr $((CI_NO_INSTALL)) || {
+        # Spawn "cmake --build ... --target install" if installation is not disabled.
+        ci_spawn "$CI_CMAKE" --build . \
+                             --config "$CI_CMAKE_BUILD_TYPE" \
+                             --target install \
+                             "${ALL_CMAKE_BUILD_FLAGS[@]}"
+    }
+    ci_expr $((CI_NO_CLEAN)) || {
+        # Spawn "make --build ... --target clean" if cleaning is not disabled.
+        ci_spawn "$CI_CMAKE" --build . \
+                             --config "$CI_CMAKE_BUILD_TYPE" \
+                             --target clean \
+                             "${ALL_CMAKE_BUILD_FLAGS[@]}"
+    }
+    ci_info "## END OF BUILD ##"
+}
+
+function usage {
+    echo "usage: $CI_SCRIPT_NAME"
+    exit 0
+}
+
+function main {
+    local opt
+    while getopts ":" opt
+    do
+        # This ain't a while-loop. It only pretends to be.
+        [[ $1 == -[?h]* || $1 == --help ]] && usage
+        ci_err "unknown option: '$1'"
+    done
+    shift $((OPTIND - 1))
+    ci_init_build
+    ci_trace_build
+    [[ $# -eq 0 ]] || {
+        ci_info "note: this program accepts environment options only"
+        ci_err "unexpected argument: '$1'"
+    }
+    ci_cleanup_old_build
+    ci_build
+}
+
+main "$@"

ci/ci_verify_configure.sh

@@ -0,0 +1,148 @@
+#!/usr/bin/env bash
+set -e
+
+# Copyright (c) 2019-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+# shellcheck source="ci/lib/ci.lib.sh"
+source "$(dirname "$0")/lib/ci.lib.sh"
+cd "$CI_TOPLEVEL_DIR"
+
+CI_SRC_DIR="$CI_TOPLEVEL_DIR"
+CI_OUT_DIR="$CI_TOPLEVEL_DIR/out"
+CI_BUILD_DIR="$CI_OUT_DIR/ci_verify_configure.$CI_TARGET_SYSTEM.$CI_TARGET_ARCH.build"
+CI_INSTALL_DIR="$CI_OUT_DIR/ci_verify_configure.$CI_TARGET_SYSTEM.$CI_TARGET_ARCH.install"
+
+function ci_init_build {
+    # Ensure that the mandatory variables are initialized.
+    CI_MAKE="${CI_MAKE:-make}"
+    [[ "$CI_TARGET_SYSTEM.$CI_TARGET_ARCH" != "$CI_BUILD_SYSTEM.$CI_BUILD_ARCH" ]] || {
+        # For native builds, set CI_CC to "cc" by default if the cc command is available.
+        # The configure script defaults CC to "gcc", which is not always a good idea.
+        [[ -x $(command -v cc) ]] && CI_CC="${CI_CC:-cc}"
+    }
+    # Ensure that the CI_ variables that cannot be customized reliably are not initialized.
+    [[ ! $CI_CONFIGURE_VARS ]] ||
+        ci_err "unsupported: \$CI_CONFIGURE_VARS='$CI_CONFIGURE_VARS'"
+    [[ ! $CI_MAKE_VARS ]] ||
+        ci_err "unsupported: \$CI_MAKE_VARS='$CI_MAKE_VARS'"
+}
+
+function ci_trace_build {
+    ci_info "## START OF CONFIGURATION ##"
+    ci_info "build arch: $CI_BUILD_ARCH"
+    ci_info "build system: $CI_BUILD_SYSTEM"
+    [[ "$CI_TARGET_SYSTEM.$CI_TARGET_ARCH" != "$CI_BUILD_SYSTEM.$CI_BUILD_ARCH" ]] && {
+        ci_info "target arch: $CI_TARGET_ARCH"
+        ci_info "target system: $CI_TARGET_SYSTEM"
+    }
+    ci_info "source directory: $CI_SRC_DIR"
+    ci_info "build directory: $CI_BUILD_DIR"
+    ci_info "install directory: $CI_INSTALL_DIR"
+    ci_info "environment option: \$CI_CONFIGURE_FLAGS: '$CI_CONFIGURE_FLAGS'"
+    ci_info "environment option: \$CI_MAKE: '$CI_MAKE'"
+    ci_info "environment option: \$CI_MAKE_FLAGS: '$CI_MAKE_FLAGS'"
+    ci_info "environment option: \$CI_CC: '$CI_CC'"
+    ci_info "environment option: \$CI_CC_FLAGS: '$CI_CC_FLAGS'"
+    ci_info "environment option: \$CI_CPP: '$CI_CPP'"
+    ci_info "environment option: \$CI_CPP_FLAGS: '$CI_CPP_FLAGS'"
+    ci_info "environment option: \$CI_AR: '$CI_AR'"
+    ci_info "environment option: \$CI_RANLIB: '$CI_RANLIB'"
+    ci_info "environment option: \$CI_LD: '$CI_LD'"
+    ci_info "environment option: \$CI_LD_FLAGS: '$CI_LD_FLAGS'"
+    ci_info "environment option: \$CI_SANITIZERS: '$CI_SANITIZERS'"
+    ci_info "environment option: \$CI_NO_TEST: '$CI_NO_TEST'"
+    ci_info "environment option: \$CI_NO_INSTALL: '$CI_NO_INSTALL'"
+    ci_info "environment option: \$CI_NO_CLEAN: '$CI_NO_CLEAN'"
+    ci_info "executable: \$CI_MAKE: $(command -V "$CI_MAKE")"
+    [[ $CI_CC ]] &&
+        ci_info "executable: \$CI_CC: $(command -V "$CI_CC")"
+    [[ $CI_CPP ]] &&
+        ci_info "executable: \$CI_CPP: $(command -V "$CI_CPP")"
+    [[ $CI_AR ]] &&
+        ci_info "executable: \$CI_AR: $(command -V "$CI_AR")"
+    [[ $CI_RANLIB ]] &&
+        ci_info "executable: \$CI_RANLIB: $(command -V "$CI_RANLIB")"
+    [[ $CI_LD ]] &&
+        ci_info "executable: \$CI_LD: $(command -V "$CI_LD")"
+    ci_info "## END OF CONFIGURATION ##"
+}
+
+function ci_cleanup_old_build {
+    if [[ -e $CI_BUILD_DIR || -e $CI_INSTALL_DIR ]]
+    then
+        ci_info "## START OF PRE-BUILD CLEANUP ##"
+        ci_spawn rm -fr "$CI_BUILD_DIR"
+        ci_spawn rm -fr "$CI_INSTALL_DIR"
+        ci_info "## END OF PRE-BUILD CLEANUP ##"
+    fi
+}
+
+function ci_build {
+    ci_info "## START OF BUILD ##"
+    # Export the configure build environment.
+    [[ $CI_CC ]] && ci_spawn export CC="$CI_CC"
+    [[ $CI_CC_FLAGS ]] && ci_spawn export CFLAGS="$CI_CC_FLAGS"
+    [[ $CI_CPP ]] && ci_spawn export CPP="$CI_CPP"
+    [[ $CI_CPP_FLAGS ]] && ci_spawn export CPPFLAGS="$CI_CPP_FLAGS"
+    [[ $CI_AR ]] && ci_spawn export AR="$CI_AR"
+    [[ $CI_RANLIB ]] && ci_spawn export RANLIB="$CI_RANLIB"
+    [[ $CI_LD ]] && ci_spawn export LD="$CI_LD"
+    [[ $CI_LD_FLAGS ]] && ci_spawn export LDFLAGS="$CI_LD_FLAGS"
+    [[ $CI_SANITIZERS ]] && {
+        ci_spawn export CFLAGS="-fsanitize=$CI_SANITIZERS ${CFLAGS:-"-O2"}"
+        ci_spawn export LDFLAGS="-fsanitize=$CI_SANITIZERS $LDFLAGS"
+    }
+    # Build!
+    ci_spawn mkdir -p "$CI_BUILD_DIR"
+    ci_spawn cd "$CI_BUILD_DIR"
+    # Spawn "configure".
+    ci_spawn "$CI_SRC_DIR/configure" --prefix="$CI_INSTALL_DIR" $CI_CONFIGURE_FLAGS
+    # Spawn "make".
+    ci_spawn "$CI_MAKE" $CI_MAKE_FLAGS
+    ci_expr $((CI_NO_TEST)) || {
+        # Spawn "make test" if testing is not disabled.
+        ci_spawn "$CI_MAKE" $CI_MAKE_FLAGS test
+    }
+    ci_expr $((CI_NO_INSTALL)) || {
+        # Spawn "make install" if installation is not disabled.
+        ci_spawn "$CI_MAKE" $CI_MAKE_FLAGS install
+    }
+    ci_expr $((CI_NO_CLEAN)) || {
+        # Spawn "make clean" and "make distclean" if cleaning is not disabled.
+        ci_spawn "$CI_MAKE" $CI_MAKE_FLAGS clean
+        ci_spawn "$CI_MAKE" $CI_MAKE_FLAGS distclean
+    }
+    ci_info "## END OF BUILD ##"
+}
+
+function usage {
+    echo "usage: $CI_SCRIPT_NAME"
+    exit 0
+}
+
+function main {
+    local opt
+    while getopts ":" opt
+    do
+        # This ain't a while-loop. It only pretends to be.
+        [[ $1 == -[?h]* || $1 == --help ]] && usage
+        ci_err "unknown option: '$1'"
+    done
+    shift $((OPTIND - 1))
+    # And... go!
+    ci_init_build
+    ci_trace_build
+    [[ $# -eq 0 ]] || {
+        ci_info "note: this program accepts environment options only"
+        ci_err "unexpected argument: '$1'"
+    }
+    ci_cleanup_old_build
+    ci_build
+}
+
+main "$@"

ci/ci_verify_makefiles.sh

@@ -0,0 +1,163 @@
+#!/usr/bin/env bash
+set -e
+
+# Copyright (c) 2019-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+# shellcheck source="ci/lib/ci.lib.sh"
+source "$(dirname "$0")/lib/ci.lib.sh"
+cd "$CI_TOPLEVEL_DIR"
+
+CI_SRC_DIR="$CI_TOPLEVEL_DIR"
+
+function ci_init_build {
+    # Ensure that the mandatory variables are initialized.
+    CI_MAKE="${CI_MAKE:-make}"
+    case "$CI_CC" in
+    ( *clang* )
+        CI_MAKEFILES="${CI_MAKEFILES:-"scripts/makefile.clang"}" ;;
+    ( *gcc* )
+        CI_MAKEFILES="${CI_MAKEFILES:-"scripts/makefile.gcc"}" ;;
+    ( * )
+        CI_MAKEFILES="${CI_MAKEFILES:-"scripts/makefile.std"}" ;;
+    esac
+}
+
+function ci_trace_build {
+    ci_info "## START OF CONFIGURATION ##"
+    ci_info "build arch: $CI_BUILD_ARCH"
+    ci_info "build system: $CI_BUILD_SYSTEM"
+    [[ "$CI_TARGET_SYSTEM.$CI_TARGET_ARCH" != "$CI_BUILD_SYSTEM.$CI_BUILD_ARCH" ]] && {
+        ci_info "target arch: $CI_TARGET_ARCH"
+        ci_info "target system: $CI_TARGET_SYSTEM"
+    }
+    ci_info "source directory: $CI_SRC_DIR"
+    ci_info "environment option: \$CI_MAKEFILES: '$CI_MAKEFILES'"
+    ci_info "environment option: \$CI_MAKE: '$CI_MAKE'"
+    ci_info "environment option: \$CI_MAKE_FLAGS: '$CI_MAKE_FLAGS'"
+    ci_info "environment option: \$CI_MAKE_VARS: '$CI_MAKE_VARS'"
+    ci_info "environment option: \$CI_CC: '$CI_CC'"
+    ci_info "environment option: \$CI_CC_FLAGS: '$CI_CC_FLAGS'"
+    ci_info "environment option: \$CI_CPP: '$CI_CPP'"
+    ci_info "environment option: \$CI_CPP_FLAGS: '$CI_CPP_FLAGS'"
+    ci_info "environment option: \$CI_AR: '$CI_AR'"
+    ci_info "environment option: \$CI_RANLIB: '$CI_RANLIB'"
+    ci_info "environment option: \$CI_LD: '$CI_LD'"
+    ci_info "environment option: \$CI_LD_FLAGS: '$CI_LD_FLAGS'"
+    ci_info "environment option: \$CI_LIBS: '$CI_LIBS'"
+    ci_info "environment option: \$CI_SANITIZERS: '$CI_SANITIZERS'"
+    ci_info "environment option: \$CI_NO_TEST: '$CI_NO_TEST'"
+    ci_info "environment option: \$CI_NO_CLEAN: '$CI_NO_CLEAN'"
+    ci_info "executable: \$CI_MAKE: $(command -V "$CI_MAKE")"
+    [[ $CI_CC ]] &&
+        ci_info "executable: \$CI_CC: $(command -V "$CI_CC")"
+    [[ $CI_CPP ]] &&
+        ci_info "executable: \$CI_CPP: $(command -V "$CI_CPP")"
+    [[ $CI_AR ]] &&
+        ci_info "executable: \$CI_AR: $(command -V "$CI_AR")"
+    [[ $CI_RANLIB ]] &&
+        ci_info "executable: \$CI_RANLIB: $(command -V "$CI_RANLIB")"
+    [[ $CI_LD ]] &&
+        ci_info "executable: \$CI_LD: $(command -V "$CI_LD")"
+    ci_info "## END OF CONFIGURATION ##"
+}
+
+function ci_cleanup_old_build {
+    # Any old makefile-based build will most likely leave a mess
+    # of object files behind if interrupted, e.g., via Ctrl+C.
+    # There may be other files behind, depending on what makefile
+    # had been used. We cannot easily enumerate all of those.
+    # Fortunately, for a clean makefiles-based build, it should be
+    # sufficient to remove the old object files only.
+    ci_info "## START OF PRE-BUILD CLEANUP ##"
+    local MY_FILE
+    find "$CI_SRC_DIR" -maxdepth 1 \( -iname "*.o" -o -iname "*.obj" \) |
+        while IFS="" read -r MY_FILE
+        do
+            ci_spawn rm -fr "$MY_FILE"
+        done
+    ci_info "## END OF PRE-BUILD CLEANUP ##"
+}
+
+function ci_build {
+    ci_info "## START OF BUILD ##"
+    # Initialize ALL_CC_FLAGS and ALL_LD_FLAGS as strings.
+    local ALL_CC_FLAGS="$CI_CC_FLAGS"
+    local ALL_LD_FLAGS="$CI_LD_FLAGS"
+    [[ $CI_SANITIZERS ]] && {
+        ALL_CC_FLAGS="-fsanitize=$CI_SANITIZERS ${ALL_CC_FLAGS:-"-O2"}"
+        ALL_LD_FLAGS="-fsanitize=$CI_SANITIZERS $ALL_LD_FLAGS"
+    }
+    # Initialize ALL_MAKE_FLAGS and ALL_MAKE_VARS as arrays.
+    local ALL_MAKE_FLAGS=($CI_MAKE_FLAGS)
+    local ALL_MAKE_VARS=()
+    [[ $CI_CC ]] && ALL_MAKE_VARS+=(CC="$CI_CC")
+    [[ $ALL_CC_FLAGS ]] && ALL_MAKE_VARS+=(CFLAGS="$ALL_CC_FLAGS")
+    [[ $CI_CPP ]] && ALL_MAKE_VARS+=(CPP="$CI_CPP")
+    [[ $CI_CPP_FLAGS ]] && ALL_MAKE_VARS+=(CPPFLAGS="$CI_CPP_FLAGS")
+    [[ $CI_AR ]] && ALL_MAKE_VARS+=(
+        AR="${CI_AR:-ar}"
+        AR_RC="${CI_AR:-ar} rc"
+    )
+    [[ $CI_RANLIB ]] && ALL_MAKE_VARS+=(RANLIB="$CI_RANLIB")
+    [[ $CI_LD ]] && ALL_MAKE_VARS+=(LD="$CI_LD")
+    [[ $ALL_LD_FLAGS ]] && ALL_MAKE_VARS+=(LDFLAGS="$ALL_LD_FLAGS")
+    [[ $CI_LIBS ]] && ALL_MAKE_VARS+=(LIBS="$CI_LIBS")
+    ALL_MAKE_VARS+=($CI_MAKE_VARS)
+    # Build!
+    local MY_MAKEFILE
+    for MY_MAKEFILE in $CI_MAKEFILES
+    do
+        ci_info "using makefile: $MY_MAKEFILE"
+        # Spawn "make".
+        ci_spawn "$CI_MAKE" -f "$MY_MAKEFILE" \
+                            "${ALL_MAKE_FLAGS[@]}" \
+                            "${ALL_MAKE_VARS[@]}"
+        ci_expr $((CI_NO_TEST)) || {
+            # Spawn "make test" if testing is not disabled.
+            ci_spawn "$CI_MAKE" -f "$MY_MAKEFILE" \
+                                "${ALL_MAKE_FLAGS[@]}" \
+                                "${ALL_MAKE_VARS[@]}" \
+                                test
+        }
+        ci_expr $((CI_NO_CLEAN)) || {
+            # Spawn "make clean" if cleaning is not disabled.
+            ci_spawn "$CI_MAKE" -f "$MY_MAKEFILE" \
+                                "${ALL_MAKE_FLAGS[@]}" \
+                                "${ALL_MAKE_VARS[@]}" \
+                                clean
+        }
+    done
+    ci_info "## END OF BUILD ##"
+}
+
+function usage {
+    echo "usage: $CI_SCRIPT_NAME"
+    exit 0
+}
+
+function main {
+    local opt
+    while getopts ":" opt
+    do
+        # This ain't a while-loop. It only pretends to be.
+        [[ $1 == -[?h]* || $1 == --help ]] && usage
+        ci_err "unknown option: '$1'"
+    done
+    shift $((OPTIND - 1))
+    # And... go!
+    ci_init_build
+    ci_trace_build
+    [[ $# -eq 0 ]] || {
+        ci_info "note: this program accepts environment options only"
+        ci_err "unexpected argument: '$1'"
+    }
+    ci_cleanup_old_build
+    ci_build
+}
+
+main "$@"

ci/lib/ci.lib.sh

@@ -0,0 +1,90 @@
+# Copyright (c) 2019-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+test -f "$BASH_SOURCE" ||
+    echo >&2 "warning: this module requires Bash version 3 or newer"
+test "${#BASH_SOURCE[@]}" -gt 1 ||
+    echo >&2 "warning: this module should be sourced from a Bash script"
+
+# Reset the locale to avoid surprises from locale-dependent commands.
+export LC_ALL=C
+export LANG=C
+export LANGUAGE=C
+
+# Reset CDPATH to avoid surprises from the "cd" command.
+export CDPATH=""
+
+# Initialize the global constants CI_SCRIPT_{NAME,DIR} and CI_TOPLEVEL_DIR.
+CI_SCRIPT_NAME="$(basename -- "$0")"
+CI_SCRIPT_DIR="$(cd "$(dirname -- "$0")" && pwd)"
+CI_TOPLEVEL_DIR="$(cd "$(dirname -- "${BASH_SOURCE[0]}")/../.." && pwd)"
+
+# Initialize the global constants CI_BUILD_{...} for the host build platform.
+CI_BUILD_ARCH="${CI_BUILD_ARCH:-"$(uname -m | tr 'A-Z/\.-' 'a-z____')"}"
+CI_BUILD_SYSTEM="${CI_BUILD_SYSTEM:-"$(uname -s | tr 'A-Z/\.-' 'a-z____')"}"
+
+# Initialize the global constants CI_TARGET_{...} for the target platform.
+CI_TARGET_ARCH="${CI_TARGET_ARCH:-"$CI_BUILD_ARCH"}"
+CI_TARGET_SYSTEM="${CI_TARGET_SYSTEM:-"$CI_BUILD_SYSTEM"}"
+
+function ci_info {
+    printf >&2 "%s: %s\\n" "$CI_SCRIPT_NAME" "$*"
+}
+
+function ci_warn {
+    printf >&2 "%s: warning: %s\\n" "$CI_SCRIPT_NAME" "$*"
+}
+
+function ci_err {
+    printf >&2 "%s: error: %s\\n" "$CI_SCRIPT_NAME" "$*"
+    exit 2
+}
+
+function ci_err_internal {
+    printf >&2 "%s: internal error: %s\\n" "$CI_SCRIPT_NAME" "$*"
+    printf >&2 "ABORTED\\n"
+    # Exit with the conventional SIGABRT code.
+    exit 134
+}
+
+function ci_expr {
+    if [[ ${*:-0} == [0-9] ]]
+    then
+        # This is the same as in the else-branch below, albeit much faster
+        # for our intended use cases.
+        return $((!$1))
+    else
+        # The funny-looking compound command "... && return $? || return $?"
+        # allows the execution to continue uninterrupted under "set -e".
+        expr >/dev/null "$@" && return $? || return $?
+    fi
+}
+
+function ci_spawn {
+    printf >&2 "%s: executing:" "$CI_SCRIPT_NAME"
+    printf >&2 " %q" "$@"
+    printf >&2 "\\n"
+    "$@"
+}
+
+# Ensure that the internal initialization is correct.
+[[ $CI_TOPLEVEL_DIR/ci/lib/ci.lib.sh -ef ${BASH_SOURCE[0]} ]] ||
+    ci_err_internal "bad or missing \$CI_TOPLEVEL_DIR"
+[[ $CI_SCRIPT_DIR/$CI_SCRIPT_NAME -ef $0 ]] ||
+    ci_err_internal "bad or missing \$CI_SCRIPT_DIR/\$CI_SCRIPT_NAME"
+[[ $CI_BUILD_ARCH && $CI_BUILD_SYSTEM ]] ||
+    ci_err_internal "missing \$CI_BUILD_ARCH or \$CI_BUILD_SYSTEM"
+[[ $CI_TARGET_ARCH && $CI_TARGET_SYSTEM ]] ||
+    ci_err_internal "missing \$CI_TARGET_ARCH or \$CI_TARGET_SYSTEM"
+
+# Ensure that the user initialization is correct.
+[[ ${CI_NO_TEST:-0} == [01] ]] ||
+    ci_err "bad boolean option: \$CI_NO_TEST: '$CI_NO_TEST'"
+[[ ${CI_NO_INSTALL:-0} == [01] ]] ||
+    ci_err "bad boolean option: \$CI_NO_INSTALL: '$CI_NO_INSTALL'"
+[[ ${CI_NO_CLEAN:-0} == [01] ]] ||
+    ci_err "bad boolean option: \$CI_NO_CLEAN: '$CI_NO_CLEAN'"

compile

@@ -3,7 +3,7 @@
 
 scriptversion=2018-03-07.03; # UTC
 
-# Copyright (C) 1999-2018 Free Software Foundation, Inc.
+# Copyright (C) 1999-2021 Free Software Foundation, Inc.
 # Written by Tom Tromey <tromey@cygnus.com>.
 #
 # This program is free software; you can redistribute it and/or modify
@@ -53,7 +53,7 @@ func_file_conv ()
 	  MINGW*)
 	    file_conv=mingw
 	    ;;
-	  CYGWIN*)
+	  CYGWIN* | MSYS*)
 	    file_conv=cygwin
 	    ;;
 	  *)
@@ -67,7 +67,7 @@ func_file_conv ()
 	mingw/*)
 	  file=`cmd //C echo "$file " | sed -e 's/"\(.*\) " *$/\1/'`
 	  ;;
-	cygwin/*)
+	cygwin/* | msys/*)
 	  file=`cygpath -m "$file" || echo "$file"`
 	  ;;
 	wine/*)

config.h.in

@@ -3,30 +3,27 @@
 /* Define to 1 if you have the <dlfcn.h> header file. */
 #undef HAVE_DLFCN_H
 
-/* Define to 1 if you have the `feenableexcept' function. */
+/* 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). */
+/* Define to 1 if you have the 'm' library (-lm). */
 #undef HAVE_LIBM
 
-/* Define to 1 if you have the `z' library (-lz). */
+/* 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 `memset' function. */
-#undef HAVE_MEMSET
-
-/* Define to 1 if you have the `pow' function. */
+/* 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 <stdio.h> header file. */
+#undef HAVE_STDIO_H
+
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
@@ -81,6 +78,18 @@
 /* Enable Intel SSE optimizations */
 #undef PNG_INTEL_SSE_OPT
 
+/* Enable LOONGARCH LSX optimizations */
+#undef PNG_LOONGARCH_LSX_OPT
+
+/* Turn on MIPS MMI optimizations at run-time */
+#undef PNG_MIPS_MMI_API_SUPPORTED
+
+/* Check for MIPS MMI support at run-time */
+#undef PNG_MIPS_MMI_CHECK_SUPPORTED
+
+/* Enable MIPS MMI optimizations */
+#undef PNG_MIPS_MMI_OPT
+
 /* Turn on MIPS MSA optimizations at run-time */
 #undef PNG_MIPS_MSA_API_SUPPORTED
 
@@ -99,31 +108,28 @@
 /* Enable POWERPC VSX optimizations */
 #undef PNG_POWERPC_VSX_OPT
 
-/* Define to 1 if you have the ANSI C header files. */
+/* Define to 1 if all of the C89 standard headers exist (not just the ones
+   required in a freestanding environment). This macro is provided for
+   backward compatibility; new code need not use it. */
 #undef STDC_HEADERS
 
-/* Define to 1 if your <sys/time.h> declares `struct tm'. */
+/* 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.  */
+   supported only 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
+/* Work around a bug in older versions of Sun C++, which did not
+   #define __restrict__ or support _Restrict or __restrict__
+   even though the corresponding Sun C compiler ended up with
+   "#define restrict _Restrict" or "#define restrict __restrict__"
+   in the previous line.  This workaround can be removed once
+   we assume Oracle Developer Studio 12.5 (2016) or later.  */
+#if defined __SUNPRO_CC && !defined __RESTRICT && !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) 2018-2024 Cosmin Truta
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
-# Last changed in libpng 1.6.25 [September 1, 2016]
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -25,8 +25,8 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.35],[png-mng-implement@lists.sourceforge.net])
-AC_CONFIG_MACRO_DIR([scripts])
+AC_INIT([libpng],[1.6.41],[png-mng-implement@lists.sourceforge.net])
+AC_CONFIG_MACRO_DIR([scripts/autoconf])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
 # color-tests requires automake 1.11 or later
@@ -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=1.6.35
+PNGLIB_VERSION=1.6.41
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=35
+PNGLIB_RELEASE=41
 
 dnl End of version number stuff
 
@@ -89,9 +89,27 @@ fi
 DFNCPP="$CPP"
 AC_SUBST(DFNCPP)
 
-# -Werror cannot be passed to GCC in CFLAGS because configure will fail (it
-# checks the compiler with a program that generates a warning), add the
-# following option to deal with this
+AC_ARG_ENABLE([tests],
+   AS_HELP_STRING([--disable-tests],
+      [do not build the test programs (default is to build)]),
+      [enable_tests="$enableval"],
+      [enable_tests=yes])
+
+AM_CONDITIONAL([ENABLE_TESTS],
+   [test "$enable_tests" != "no"])
+
+AC_ARG_ENABLE([tools],
+   AS_HELP_STRING([--disable-tools],
+      [do not build the auxiliary tools (default is to build)]),
+      [enable_tools="$enableval"],
+      [enable_tools=yes])
+
+AM_CONDITIONAL([ENABLE_TOOLS],
+   [test "$enable_tools" != "no"])
+
+# -Werror cannot be passed to GCC in CFLAGS because configure will fail
+# (it checks the compiler with a program that generates a warning).
+# Add the following option to deal with this:
 AC_ARG_VAR(PNG_COPTS,
    [additional flags for the C compiler, use this for options that would]
    [cause configure itself to fail])
@@ -114,10 +132,10 @@ AC_ARG_ENABLE(werror,
       CFLAGS="$sav_CFLAGS"
     fi],)
 
-# For GCC 5 the default mode for C is -std=gnu11 instead of -std=gnu89
-# In pngpriv.h we request just the POSIX 1003.1 and C89 APIs by defining _POSIX_SOURCE to 1
-# This is incompatible with the new default mode, so we test for that and force the 
-# "-std=c89" compiler option:
+# For GCC 5 the default mode for C is -std=gnu11 instead of -std=gnu89.
+# In pngpriv.h we request just the POSIX 1003.1 and C89 APIs by defining
+# _POSIX_SOURCE to 1. This is incompatible with the new default mode, so
+# we test for that and force the "-std=c89" compiler option:
 AC_MSG_CHECKING([if we need to force back C standard to C89])
 AC_COMPILE_IFELSE(
    [AC_LANG_PROGRAM([
@@ -133,23 +151,17 @@ AC_COMPILE_IFELSE(
    CFLAGS="$CFLAGS -std=c89"
 ])
 
-# Checks for header files.
-AC_HEADER_STDC
-
-# Checks for typedefs, structures, and compiler characteristics.
-AC_C_CONST
-AC_TYPE_SIZE_T
+# Checks for structures and compiler characteristics.
 AC_STRUCT_TM
 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)) )
+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
-# is soft (the corresponding test program is not built).
-AC_CHECK_FUNC([clock_gettime],,[AC_MSG_WARN([not building timepng])])
+# Some later POSIX 1003.1 functions are required for test programs, failure
+# here is soft (the corresponding test program is not built).
+AC_CHECK_FUNC([clock_gettime], , [AC_MSG_WARN([not building timepng])])
 AM_CONDITIONAL([HAVE_CLOCK_GETTIME], [test "$ac_cv_func_clock_gettime" = "yes"])
 
 AC_ARG_WITH(zlib-prefix,
@@ -157,8 +169,9 @@ AC_ARG_WITH(zlib-prefix,
       [prefix that may have been used in installed zlib]),
       [ZPREFIX=${withval}],
       [ZPREFIX='z_'])
-AC_CHECK_LIB(z, zlibVersion, ,
-    AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, , AC_MSG_ERROR(zlib not installed)))
+AC_CHECK_LIB([z], [zlibVersion], ,
+  [AC_CHECK_LIB([z], [${ZPREFIX}zlibVersion], ,
+     [AC_MSG_ERROR([zlib not installed])])])
 
 # The following is for pngvalid, to ensure it catches FP errors even on
 # platforms that don't enable FP exceptions, the function appears in the math
@@ -297,7 +310,7 @@ AC_ARG_ENABLE([unversioned-libpng-config],
 AM_CONDITIONAL([DO_INSTALL_LIBPNG_CONFIG],
    [test "$enable_unversioned_libpng_config" != "no"])
 
-# HOST SPECIFIC OPTIONS
+# HOST-SPECIFIC OPTIONS
 # =====================
 #
 # DEFAULT
@@ -315,24 +328,33 @@ AC_ARG_ENABLE([hardware-optimizations],
          enable_mips_msa=no
          AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
            [Disable MIPS_MSA optimizations])
+         enable_mips_mmi=no
+         AC_DEFINE([PNG_MIPS_MMI_OPT], [0],
+           [Disable MIPS_MMI 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])
+         enable_loongarch_lsx=no
+         AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [0],
+           [Disable LOONGARCH_LSX optimizations])
          ;;
       *)
          # allow enabling hardware optimization on any system:
          case "$host_cpu" in
             arm*|aarch64*)
               enable_arm_neon=yes
-              AC_DEFINE([PNG_ARM_NEON_OPT], [0],
+              AC_DEFINE([PNG_ARM_NEON_OPT], [2],
                 [Enable ARM_NEON optimizations])
               ;;
             mipsel*|mips64el*)
+              enable_mips_mmi=yes
               enable_mips_msa=yes
-              AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
+              AC_DEFINE([PNG_MIPS_MMI_OPT], [1],
+                [Enable MIPS_MMI optimizations])
+              AC_DEFINE([PNG_MIPS_MSA_OPT], [2],
                 [Enable MIPS_MSA optimizations])
               ;;
             i?86|x86_64)
@@ -345,6 +367,11 @@ AC_ARG_ENABLE([hardware-optimizations],
               AC_DEFINE([PNG_POWERPC_VSX_OPT], [2],
                 [Enable POWERPC VSX optimizations])
               ;;
+            loongarch*)
+              enable_loongarch_lsx=yes
+              AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [1],
+                [Enable LOONGARCH_LSX optimizations])
+              ;;
          esac
          ;;
    esac])
@@ -367,7 +394,7 @@ AC_ARG_ENABLE([arm-neon],
          AC_DEFINE([PNG_ARM_NEON_OPT], [0],
                    [Disable ARM Neon optimizations])
          # Prevent inclusion of the assembler files below:
-         enable_arm_neon=no;;
+         enable_arm_neon=no ;;
       check)
          AC_DEFINE([PNG_ARM_NEON_CHECK_SUPPORTED], [],
                    [Check for ARM Neon support at run-time]);;
@@ -384,19 +411,19 @@ AC_ARG_ENABLE([arm-neon],
          AC_MSG_ERROR([--enable-arm-neon=${enable_arm_neon}: invalid value])
    esac])
 
-# Add ARM specific files to all builds where the host_cpu is arm ('arm*') or
-# where ARM optimizations were explicitly requested (this allows a fallback if a
-# future host CPU does not match 'arm*')
+# Add ARM-specific files to all builds where $host_cpu is arm ('arm*') or
+# where ARM optimizations were explicitly requested (this allows a fallback
+# if a future host CPU does not match 'arm*')
 
 AM_CONDITIONAL([PNG_ARM_NEON],
    [test "$enable_arm_neon" != 'no' &&
     case "$host_cpu" in
-      arm*|aarch64*) :;;
-      *)    test "$enable_arm_neon" != '';;
+      arm*|aarch64*) : ;;
+      *)    test "$enable_arm_neon" != '' ;;
     esac])
 
 # MIPS
-# ===
+# ====
 #
 # MIPS MSA (SIMD) support.
 
@@ -413,7 +440,7 @@ AC_ARG_ENABLE([mips-msa],
          AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
                    [Disable MIPS MSA optimizations])
          # Prevent inclusion of the assembler files below:
-         enable_mips_msa=no;;
+         enable_mips_msa=no ;;
       check)
          AC_DEFINE([PNG_MIPS_MSA_CHECK_SUPPORTED], [],
                    [Check for MIPS MSA support at run-time]);;
@@ -430,12 +457,57 @@ AC_ARG_ENABLE([mips-msa],
          AC_MSG_ERROR([--enable-mips-msa=${enable_mips_msa}: invalid value])
    esac])
 
+# Add MIPS-specific files to all builds where $host_cpu is mips ('mips*') or
+# where MIPS optimizations were explicitly requested (this allows a fallback
+# if a future host CPU does not match 'mips*')
+
+AM_CONDITIONAL([PNG_MIPS_MSA],
+   [test "$enable_mips_msa" != 'no' &&
+    case "$host_cpu" in
+      mipsel*|mips64el*) : ;;
+    esac])
+
+# MIPS
+# ===
+#
+# MIPS MMI (SIMD) support.
+
+AC_ARG_ENABLE([mips-mmi],
+   AS_HELP_STRING([[[--enable-mips-mmi]]],
+      [Enable MIPS MMI optimizations: =no/off, check, api, yes/on:]
+      [no/off: disable the optimizations; check: use internal checking code]
+      [(deprecated and poorly supported); api: disable by default, enable by]
+      [a call to png_set_option; yes/on: turn on unconditionally.]
+      [If not specified: determined by the compiler.]),
+   [case "$enableval" in
+      no|off)
+         # disable the default enabling on __mips_mmi systems:
+         AC_DEFINE([PNG_MIPS_MMI_OPT], [0],
+                   [Disable MIPS MMI optimizations])
+         # Prevent inclusion of the assembler files below:
+         enable_mips_mmi=no;;
+      check)
+         AC_DEFINE([PNG_MIPS_MMI_CHECK_SUPPORTED], [],
+                   [Check for MIPS MMI support at run-time]);;
+      api)
+         AC_DEFINE([PNG_MIPS_MMI_API_SUPPORTED], [],
+                   [Turn on MIPS MMI optimizations at run-time]);;
+      yes|on)
+         AC_DEFINE([PNG_MIPS_MMI_OPT], [1],
+                   [Enable MIPS MMI optimizations])
+         AC_MSG_WARN([--enable-mips-mmi: please specify 'check' or 'api', if]
+            [you want the optimizations unconditionally pass '-mloongson-mmi -march=loongson3a']
+            [to the compiler.]);;
+      *)
+         AC_MSG_ERROR([--enable-mips-mmi=${enable_mips_mmi}: invalid value])
+   esac])
+
 # Add MIPS specific files to all builds where the host_cpu is mips ('mips*') or
 # where MIPS optimizations were explicitly requested (this allows a fallback if a
 # future host CPU does not match 'mips*')
 
-AM_CONDITIONAL([PNG_MIPS_MSA],
-   [test "$enable_mips_msa" != 'no' &&
+AM_CONDITIONAL([PNG_MIPS_MMI],
+   [test "$enable_mips_mmi" != 'no' &&
     case "$host_cpu" in
       mipsel*|mips64el*) :;;
     esac])
@@ -457,7 +529,7 @@ AC_ARG_ENABLE([intel-sse],
          AC_DEFINE([PNG_INTEL_SSE_OPT], [0],
                    [Disable Intel SSE optimizations])
          # Prevent inclusion of the assembler files below:
-         enable_intel_sse=no;;
+         enable_intel_sse=no ;;
       yes|on)
          AC_DEFINE([PNG_INTEL_SSE_OPT], [1],
                    [Enable Intel SSE optimizations]);;
@@ -465,18 +537,18 @@ AC_ARG_ENABLE([intel-sse],
          AC_MSG_ERROR([--enable-intel-sse=${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*')
+# Add Intel-specific files to all builds where $host_cpu is Intel ('x86*') or
+# where Intel optimizations were explicitly requested (this allows a fallback
+# if a future host CPU does not match 'x86*')
 AM_CONDITIONAL([PNG_INTEL_SSE],
    [test "$enable_intel_sse" != 'no' &&
     case "$host_cpu" in
-      i?86|x86_64) :;;
-      *)    test "$enable_intel_sse" != '';;
+      i?86|x86_64) : ;;
+      *)    test "$enable_intel_sse" != '' ;;
     esac])
 
 # PowerPC
-# ===
+# =======
 #
 # PowerPC VSX (SIMD) support.
 
@@ -492,8 +564,8 @@ AS_HELP_STRING([[[--enable-powerpc-vsx]]],
          # 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;;
+         # 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])
@@ -507,21 +579,83 @@ AS_HELP_STRING([[[--enable-powerpc-vsx]]],
                    [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.]);;
+            [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*')
+# Add PowerPC-specific files to all builds where $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*) :;;
+      powerpc*|ppc64*) : ;;
     esac])
 
+# LOONGARCH
+# ===
+#
+# LOONGARCH LSX (SIMD) support
+
+if test "$LSX_CFLAGS" = ''; then
+    LSX_CFLAGS="-mlsx"
+fi
+
+compiler_support_loongarch_lsx=no
+AC_MSG_CHECKING(whether to use loongarch LSX intrinsics)
+save_CFLAGS=$CFLAGS
+CFLAGS="$CFLAGS $LSX_CFLAGS"
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+#include<lsxintrin.h>
+int main(){
+    __m128i a, b, c;
+    a = __lsx_vadd_w(b, c);
+    return 0;
+}]])],compiler_support_loongarch_lsx=yes)
+CFLAGS=$save_CFLAGS
+AC_MSG_RESULT($compiler_support_loongarch_lsx)
+
+AC_ARG_ENABLE([loongarch-lsx],
+   AS_HELP_STRING([[[--enable-loongarch-lsx]]],
+      [Enable LOONGARCH LSX optimizations: =no/off, yes/on:]
+      [no/off: disable the optimizations;]
+      [yes/on: turn on unconditionally.]
+      [If not specified: determined by the compiler.]),
+   [case "$enableval" in
+      no|off)
+         # disable the default enabling on __loongarch_simd systems:
+         AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [0],
+                   [Disable LOONGARCH LSX optimizations])
+         # Prevent inclusion of the assembler files below:
+         enable_loongarch_lsx=no;;
+      yes|on)
+         AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [1],
+                   [Enable LOONGARCH LSX optimizations])
+         ;;
+      *)
+         AC_MSG_ERROR([--enable-loongarch-lsx=${enable_loongarch_lsx}: invalid value])
+   esac])
+
+if test "$enable_loongarch_lsx" != 'no'; then
+   if test $compiler_support_loongarch_lsx = yes; then
+      AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [1], [Enable LOONGARCH LSX optimizations])
+   else
+      AC_MSG_WARN([Compiler does not support loongarch LSX.])
+   fi
+fi
+
+# Add LOONGARCH specific files to all builds where the host_cpu is loongarch ('loongarch*') or
+# where LOONGARCH optimizations were explicitly requested (this allows a fallback if a
+# future host CPU does not match 'loongarch*')
+
+AM_CONDITIONAL([PNG_LOONGARCH_LSX],
+   [test "$enable_loongarch_lsx" != 'no' && test $compiler_support_loongarch_lsx = yes &&
+    case "$host_cpu" in
+      loongarch*) :;;
+      *)    test "$enable_loongarch_lsx" != '';;
+    esac])
 
 AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])
 

contrib/arm-neon/android-ndk.c

@@ -2,7 +2,6 @@
  *
  * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by John Bowler, 2014.
- * Last changed in libpng 1.6.10 [March 6, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -24,6 +23,7 @@
  * has been compiled only, not linked: no version of the library has been found,
  * only the header files exist in the NDK.
  */
+
 #include <cpu-features.h>
 
 static int

contrib/arm-neon/linux-auxv.c

@@ -2,7 +2,6 @@
  *
  * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.10 [March 6, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -22,6 +21,7 @@
  * This generic __linux__ implementation requires reading /proc/self/auxv and
  * looking at each element for one that records NEON capabilities.
  */
+
 #include <unistd.h> /* for POSIX 1003.1 */
 #include <errno.h>  /* for EINTR */
 

contrib/arm-neon/linux.c

@@ -1,6 +1,5 @@
 /* contrib/arm-neon/linux.c
  *
- * Last changed in libpng 1.6.31 [July 27, 2017]
  * Copyright (c) 2014, 2017 Glenn Randers-Pehrson
  * Written by John Bowler, 2014, 2017.
  *
@@ -19,6 +18,7 @@
  * 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>
 
 static int

contrib/conftest/pngcp.dfa

@@ -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/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

@@ -5,8 +5,6 @@
  * 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.
  *

contrib/gregbook/readpng2.c

@@ -146,7 +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/libtests/gentests.sh

@@ -2,8 +2,6 @@
 #
 # Copyright (c) 2013 John Cunningham Bowler
 #
-# Last changed in libpng 1.6.0 [February 14, 2013]
-#
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
 # and license in png.h

contrib/libtests/makepng.c

@@ -3,8 +3,6 @@
 /* Copyright: */
 #define COPYRIGHT "\251 2013,2015 John Cunningham Bowler"
 /*
- * Last changed in libpng 1.6.20 [November 24, 2015]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -299,25 +297,28 @@ generate_palette(png_colorp palette, png_bytep trans, int bit_depth,
             unsigned int x, y;
             volatile unsigned int ip = 0;
 
-            for (x=0; x<size; ++x) for (y=0; y<size; ++y)
+            for (x=0; x<size; ++x)
             {
-               ip = x + (size * y);
+               for (y=0; y<size; ++y)
+               {
+                  ip = x + (size * y);
 
-               /* size is at most 16, so the scaled value below fits in 16 bits
-                */
-#              define interp(pos, c1, c2) ((pos * c1) + ((size-pos) * c2))
-#              define xyinterp(x, y, c1, c2, c3, c4) (((size * size / 2) +\
-                  (interp(x, c1, c2) * y + (size-y) * interp(x, c3, c4))) /\
-                  (size*size))
+                  /* size is at most 16, so the scaled value below fits in 16 bits
+                  */
+#                 define interp(pos, c1, c2) ((pos * c1) + ((size-pos) * c2))
+#                 define xyinterp(x, y, c1, c2, c3, c4) (((size * size / 2) +\
+                     (interp(x, c1, c2) * y + (size-y) * interp(x, c3, c4))) /\
+                     (size*size))
 
-               set_color(palette+ip, trans+ip,
-                  /* color:    green, red,blue,white */
-                  xyinterp(x, y,   0, 255,   0, 255),
-                  xyinterp(x, y, 255,   0,   0, 255),
-                  xyinterp(x, y,   0,   0, 255, 255),
-                  /* alpha:        0, 102, 204, 255) */
-                  xyinterp(x, y,   0, 102, 204, 255),
-                  gamma_table);
+                  set_color(palette+ip, trans+ip,
+                     /* color:    green, red,blue,white */
+                     xyinterp(x, y,   0, 255,   0, 255),
+                     xyinterp(x, y, 255,   0,   0, 255),
+                     xyinterp(x, y,   0,   0, 255, 255),
+                     /* alpha:        0, 102, 204, 255) */
+                     xyinterp(x, y,   0, 102, 204, 255),
+                     gamma_table);
+               }
             }
 
             return ip+1;
@@ -396,7 +397,7 @@ generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
       image_size_of_type(color_type, bit_depth, colors, small)-1;
    png_uint_32 depth_max = (1U << bit_depth)-1; /* up to 65536 */
 
-   if (colors[0] == 0) if (small)
+   if (colors[0] == 0 && small)
    {
       unsigned int pixel_depth = pixel_depth_of_type(color_type, bit_depth);
 
@@ -495,7 +496,7 @@ generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
          case 32:
          case 48:
          case 64:
-            /* The rows are filled by an alogorithm similar to the above, in the
+            /* The rows are filled by an algorithm similar to the above, in the
              * first row pixel bytes are all equal, increasing from 0 by 1 for
              * each pixel.  In the second row the bytes within a pixel are
              * incremented 1,3,5,7,... from the previous row byte.  Using an odd
@@ -661,7 +662,7 @@ 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 +673,8 @@ 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 +689,9 @@ 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 +708,10 @@ 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 +813,7 @@ 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 +825,7 @@ 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)
@@ -858,10 +859,13 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,
       {
          unsigned int i;
 
-         if (real_gamma == 45455) for (i=0; i<256; ++i)
+         if (real_gamma == 45455)
          {
-            gamma_table[i] = (png_byte)i;
-            conv = 1.;
+            for (i=0; i<256; ++i)
+            {
+               gamma_table[i] = (png_byte)i;
+               conv = 1.;
+            }
          }
 
          else
@@ -1378,10 +1382,10 @@ 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;
 
@@ -1430,10 +1434,13 @@ find_parameters(png_const_charp what, png_charp param, png_charp *list,
    for (i=0; *param && i<nparams; ++i)
    {
       list[i] = param;
-      while (*++param) if (*param == '\n' || *param == ':')
+      while (*++param)
       {
-         *param++ = 0; /* Terminate last parameter */
-         break;        /* And start a new one. */
+         if (*param == '\n' || *param == ':')
+         {
+            *param++ = 0; /* Terminate last parameter */
+            break;        /* And start a new one. */
+         }
       }
    }
 
@@ -1856,7 +1863,7 @@ 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;
 
@@ -1869,7 +1876,7 @@ main(int argc, char **argv)
          }
    }
 
-   /* small and colors are incomparible (will probably crash if both are used at
+   /* small and colors are incompatible (will probably crash if both are used at
     * the same time!)
     */
    if (small && colors[0] != 0)

contrib/libtests/pngimage.c

@@ -1,9 +1,9 @@
+
 /* pngimage.c
  *
+ * Copyright (c) 2021 Cosmin Truta
  * Copyright (c) 2015,2016 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.24 [August 4, 2016]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -12,6 +12,7 @@
  * using png_read_png and then write with png_write_png.  Test all possible
  * transforms.
  */
+
 #include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
@@ -317,11 +318,10 @@ transform_name(int t)
 
    t &= -t; /* first set bit */
 
-   for (i=0; i<TTABLE_SIZE; ++i) if (transform_info[i].name != NULL)
-   {
-      if ((transform_info[i].transform & t) != 0)
-         return transform_info[i].name;
-   }
+   for (i=0; i<TTABLE_SIZE; ++i)
+      if (transform_info[i].name != NULL)
+         if ((transform_info[i].transform & t) != 0)
+            return transform_info[i].name;
 
    return "invalid transform";
 }
@@ -338,13 +338,16 @@ validate_T(void)
 {
    unsigned int i;
 
-   for (i=0; i<TTABLE_SIZE; ++i) if (transform_info[i].name != NULL)
+   for (i=0; i<TTABLE_SIZE; ++i)
    {
-      if (transform_info[i].when & TRANSFORM_R)
-         read_transforms |= transform_info[i].transform;
+      if (transform_info[i].name != NULL)
+      {
+         if (transform_info[i].when & TRANSFORM_R)
+            read_transforms |= transform_info[i].transform;
 
-      if (transform_info[i].when & TRANSFORM_W)
-         write_transforms |= transform_info[i].transform;
+         if (transform_info[i].when & TRANSFORM_W)
+            write_transforms |= transform_info[i].transform;
+      }
    }
 
    /* Reversible transforms are those which are supported on both read and
@@ -962,21 +965,24 @@ update_display(struct display *dp)
       int bd = dp->bit_depth;
       unsigned int i;
 
-      for (i=0; i<TTABLE_SIZE; ++i) if (transform_info[i].name != NULL)
+      for (i=0; i<TTABLE_SIZE; ++i)
       {
-         int transform = transform_info[i].transform;
+         if (transform_info[i].name != NULL)
+         {
+            int transform = transform_info[i].transform;
 
-         if ((transform_info[i].valid_chunks == 0 ||
-               (transform_info[i].valid_chunks & chunks) != 0) &&
-            (transform_info[i].color_mask_required & ct) ==
-               transform_info[i].color_mask_required &&
-            (transform_info[i].color_mask_absent & ct) == 0 &&
-            (transform_info[i].bit_depths & bd) != 0 &&
-            (transform_info[i].when & TRANSFORM_R) != 0)
-            active |= transform;
+            if ((transform_info[i].valid_chunks == 0 ||
+                  (transform_info[i].valid_chunks & chunks) != 0) &&
+               (transform_info[i].color_mask_required & ct) ==
+                  transform_info[i].color_mask_required &&
+               (transform_info[i].color_mask_absent & ct) == 0 &&
+               (transform_info[i].bit_depths & bd) != 0 &&
+               (transform_info[i].when & TRANSFORM_R) != 0)
+               active |= transform;
 
-         else if ((transform_info[i].when & TRANSFORM_R) != 0)
-            inactive |= transform;
+            else if ((transform_info[i].when & TRANSFORM_R) != 0)
+               inactive |= transform;
+         }
       }
 
       /* Some transforms appear multiple times in the table; the 'active' status
@@ -1000,8 +1006,9 @@ compare_read(struct display *dp, int applied_transforms)
    int interlace_method, compression_method, filter_method;
    const char *e = NULL;
 
-   png_get_IHDR(dp->read_pp, dp->read_ip, &width, &height, &bit_depth,
-      &color_type, &interlace_method, &compression_method, &filter_method);
+   if (!png_get_IHDR(dp->read_pp, dp->read_ip, &width, &height, &bit_depth,
+      &color_type, &interlace_method, &compression_method, &filter_method))
+      display_log(dp, LIBPNG_BUG, "png_get_IHDR failed");
 
 #  define C(item) if (item != dp->item) \
       display_log(dp, APP_WARNING, "IHDR " #item "(%lu) changed to %lu",\
@@ -1081,8 +1088,9 @@ compare_read(struct display *dp, int applied_transforms)
                size_t x;
 
                /* Find the first error */
-               for (x=0; x<rowbytes-1; ++x) if (row[x] != orig[x])
-                  break;
+               for (x=0; x<rowbytes-1; ++x)
+                  if (row[x] != orig[x])
+                     break;
 
                display_log(dp, APP_FAIL,
                   "byte(%lu,%lu) changed 0x%.2x -> 0x%.2x",
@@ -1137,6 +1145,7 @@ compare_read(struct display *dp, int applied_transforms)
                display_log(dp, LIBPNG_ERROR, "invalid colour type %d",
                   color_type);
                /*NOTREACHED*/
+               memset(sig_bits, 0, sizeof(sig_bits));
                bpp = 0;
                break;
          }
@@ -1198,7 +1207,7 @@ compare_read(struct display *dp, int applied_transforms)
                sig_bits[0] = (png_byte)b;
                break;
 
-            case 4: /* Relicate twice */
+            case 4: /* Replicate twice */
                /* Value is 1, 2, 3 or 4 */
                b = 0xf & ((0xf << 4) >> sig_bits[0]);
                b |= b << 4;
@@ -1446,7 +1455,7 @@ 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 +1581,7 @@ 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 +1683,7 @@ 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)
@@ -1686,8 +1695,9 @@ main(const int argc, const char * const * const argv)
 
                printf("%s: pngimage ", pass ? "PASS" : "FAIL");
 
-               for (j=1; j<option_end; ++j) if (j != ilog)
-                  printf("%s ", argv[j]);
+               for (j=1; j<option_end; ++j)
+                  if (j != ilog)
+                     printf("%s ", argv[j]);
 
                printf("%s\n", d.filename);
             }

contrib/libtests/pngstest.c

@@ -1,7 +1,7 @@
-/*-
- * pngstest.c
+
+/* pngstest.c
  *
- * Last changed in libpng 1.6.31 [July 27, 2017]
+ * Copyright (c) 2021 Cosmin Truta
  * Copyright (c) 2013-2017 John Cunningham Bowler
  *
  * This code is released under the libpng license.
@@ -10,8 +10,9 @@
  *
  * Test for the PNG 'simplified' APIs.
  */
+
 #define _ISOC90_SOURCE 1
-#define MALLOC_CHECK_ 2/*glibc facility: turn on debugging*/
+#define MALLOC_CHECK_ 2 /*glibc facility: turn on debugging*/
 
 #include <stddef.h>
 #include <stdlib.h>
@@ -372,7 +373,7 @@ 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",
@@ -1150,7 +1151,7 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
  *
  * 2) Remove color by mapping to grayscale.  (Grayscale to color is a no-op.)
  *
- * 3) Convert between 8-bit and 16-bit components.  (Both directtions are
+ * 3) Convert between 8-bit and 16-bit components.  (Both directions are
  *    relevant.)
  *
  * This gives the following base format conversion matrix:
@@ -2346,8 +2347,8 @@ 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 = "";
@@ -2602,12 +2603,12 @@ 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;
    png_uint_32 y;
@@ -2701,7 +2702,7 @@ compare_two_images(Image *a, Image *b, int via_linear,
             {
                if ((a->opts & ACCUMULATE) == 0)
                {
-                  char pindex[9];
+                  char pindex[16];
                   sprintf(pindex, "%lu[%lu]", (unsigned long)y,
                      (unsigned long)a->image.colormap_entries);
                   logerror(a, a->file_name, ": bad pixel index: ", pindex);
@@ -2712,12 +2713,12 @@ compare_two_images(Image *a, Image *b, int via_linear,
             else if (y >= b->image.colormap_entries)
             {
                if ((b->opts & ACCUMULATE) == 0)
-                  {
-                  char pindex[9];
+               {
+                  char pindex[16];
                   sprintf(pindex, "%lu[%lu]", (unsigned long)y,
                      (unsigned long)b->image.colormap_entries);
                   logerror(b, b->file_name, ": bad pixel index: ", pindex);
-                  }
+               }
                result = 0;
             }
 
@@ -2726,7 +2727,7 @@ 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];
@@ -2790,8 +2791,7 @@ 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.
@@ -2821,8 +2821,11 @@ compare_two_images(Image *a, Image *b, int via_linear,
          bchannels = component_loc(bloc, formatb);
 
          /* Hence the btoa array. */
-         for (i=0; i<4; ++i) if (bloc[i] < 4)
-            btoa[bloc[i]] = aloc[i]; /* may be '4' for alpha */
+         for (i=0; i<4; ++i)
+         {
+            if (bloc[i] < 4)
+               btoa[bloc[i]] = aloc[i]; /* may be '4' for alpha */
+         }
 
          if (alpha_added)
             alpha_added = bloc[0]; /* location of alpha channel in image b */
@@ -2932,7 +2935,7 @@ 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];
@@ -3210,10 +3213,10 @@ write_one_file(Image *output, Image *image, int convert_to_8bit)
    else if (image->opts & USE_FILE)
    {
 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
-      static int counter = 0;
+      static unsigned int counter = 0;
       char name[32];
 
-      sprintf(name, "%s%d.png", tmpf, ++counter);
+      sprintf(name, "%s%u.png", tmpf, ++counter);
 
       if (png_image_write_to_file(&image->image, name, convert_to_8bit,
          image->buffer+16, (png_int_32)image->stride, image->colormap))
@@ -3627,7 +3630,7 @@ 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

@@ -1,7 +1,7 @@
 
 /* pngunknown.c - test the read side unknown chunk handling
  *
- * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 2021 Cosmin Truta
  * Copyright (c) 2015,2017 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
@@ -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: */
@@ -370,7 +370,9 @@ find_by_flag(png_uint_32 flag)
 {
    int i = NINFO;
 
-   while (--i >= 0) if (chunk_info[i].flag == flag) return i;
+   while (--i >= 0)
+      if (chunk_info[i].flag == flag)
+         return i;
 
    fprintf(stderr, "pngunknown: internal error\n");
    exit(4);
@@ -547,27 +549,30 @@ read_callback(png_structp pp, png_unknown_chunkp pc)
 
       case PNG_HANDLE_CHUNK_AS_DEFAULT:
       case PNG_HANDLE_CHUNK_NEVER:
-         discard = 1/*handled; discard*/;
+         discard = 1; /*handled; discard*/
          break;
 
       case PNG_HANDLE_CHUNK_IF_SAFE:
       case PNG_HANDLE_CHUNK_ALWAYS:
-         discard = 0/*not handled; keep*/;
+         discard = 0; /*not handled; keep*/
          break;
    }
 
    /* Also store information about this chunk in the display, the relevant flag
     * is set if the chunk is to be kept ('not handled'.)
     */
-   if (chunk >= 0) if (!discard) /* stupidity to stop a GCC warning */
+   if (chunk >= 0)
    {
-      png_uint_32 flag = chunk_info[chunk].flag;
+      if (!discard) /* stupidity to stop a GCC warning */
+      {
+         png_uint_32 flag = chunk_info[chunk].flag;
 
-      if (pc->location & PNG_AFTER_IDAT)
-         d->after_IDAT |= flag;
+         if (pc->location & PNG_AFTER_IDAT)
+            d->after_IDAT |= flag;
 
-      else
-         d->before_IDAT |= flag;
+         else
+            d->before_IDAT |= flag;
+      }
    }
 
    /* However if there is no support to store unknown chunks don't ask libpng to
@@ -841,8 +846,9 @@ check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
             {
                png_uint_32 y;
 
-               for (y=0; y<height; ++y) if (PNG_ROW_IN_INTERLACE_PASS(y, ipass))
-                  png_read_row(d->png_ptr, NULL, NULL);
+               for (y=0; y<height; ++y)
+                  if (PNG_ROW_IN_INTERLACE_PASS(y, ipass))
+                     png_read_row(d->png_ptr, NULL, NULL);
             }
          }
       } /* interlaced */
@@ -1091,15 +1097,15 @@ perform_one_test_safe(FILE *fp, int argc, const char **argv,
 
 static const char *standard_tests[] =
 {
- "discard", "default=discard", 0,
- "save", "default=save", 0,
- "if-safe", "default=if-safe", 0,
- "vpAg", "vpAg=if-safe", 0,
- "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", "eXIf=save", 0,
- 0/*end*/
+   "discard", "default=discard", NULL,
+   "save", "default=save", NULL,
+   "if-safe", "default=if-safe", NULL,
+   "vpAg", "vpAg=if-safe", NULL,
+   "sTER", "sTER=if-safe", NULL,
+   "IDAT", "default=discard", "IDAT=save", NULL,
+   "sAPI", "bKGD=save", "cHRM=save", "gAMA=save", "all=discard", "iCCP=save",
+      "sBIT=save", "sRGB=save", "eXIf=save", NULL,
+   NULL /*end*/
 };
 
 static PNG_NORETURN void
@@ -1115,7 +1121,7 @@ int
 main(int argc, const char **argv)
 {
    FILE *fp;
-   png_uint_32 default_flags[4/*valid,unknown{before,after}*/];
+   png_uint_32 default_flags[4]; /*valid,unknown{before,after}*/
    int strict = 0, default_tests = 0;
    const char *count_argv = "default=save";
    const char *touch_file = NULL;
@@ -1153,8 +1159,9 @@ main(int argc, const char **argv)
    /* GCC BUG: if (default_tests && argc != 1) triggers some weird GCC argc
     * optimization which causes warnings with -Wstrict-overflow!
     */
-   else if (default_tests) if (argc != 1)
-      usage(d.program, "extra arguments");
+   else if (default_tests)
+      if (argc != 1)
+         usage(d.program, "extra arguments");
 
    /* The name of the test file is the last argument; remove it. */
    d.file = argv[--argc];
@@ -1216,7 +1223,11 @@ main(int argc, const char **argv)
          const char *result;
          int arg_count = 0;
 
-         while (*next) ++next, ++arg_count;
+         while (*next != NULL)
+         {
+            ++next;
+            ++arg_count;
+         }
 
          perform_one_test_safe(fp, arg_count, test, default_flags, &d,
             this_test);

contrib/libtests/pngvalid.c

@@ -1,7 +1,7 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.31 [July 27, 2017]
+ * Copyright (c) 2021 Cosmin Truta
  * Copyright (c) 2014-2017 John Cunningham Bowler
  *
  * This code is released under the libpng license.
@@ -21,6 +21,8 @@
 #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 */
+#define _DEFAULT_SOURCE 1 /* For the floating point exception extension */
 
 #include <signal.h>
 #include <stdio.h>
@@ -961,7 +963,7 @@ 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
@@ -2589,7 +2591,7 @@ 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.
@@ -3687,8 +3689,8 @@ 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
@@ -3696,7 +3698,7 @@ 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 */
 
@@ -4337,7 +4339,7 @@ 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);
@@ -4413,7 +4415,7 @@ 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,
@@ -4645,7 +4647,7 @@ 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)
 
@@ -4705,7 +4707,7 @@ 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.
           */
@@ -5468,14 +5470,14 @@ 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)
@@ -5821,8 +5823,9 @@ test_standard(png_modifier* const pm, png_byte const colour_type,
       for (interlace_type = PNG_INTERLACE_NONE;
            interlace_type < INTERLACE_LAST; ++interlace_type)
       {
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
-            interlace_type, 0, 0, 0), do_read_interlace, pm->use_update_info);
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+            0/*palette*/, interlace_type, 0, 0, 0), do_read_interlace,
+            pm->use_update_info);
 
          if (fail(pm))
             return 0;
@@ -5869,53 +5872,56 @@ 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)
    {
       png_uint_32 h, w;
 
-      for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo])
+      for (h=1; h<=16; h+=hinc[bdlo])
       {
-         /* First test all the 'size' images against the sequential
-          * reader using libpng to deinterlace (where required.)  This
-          * validates the write side of libpng.  There are four possibilities
-          * to validate.
-          */
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
-            PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/,
-            pm->use_update_info);
+         for (w=1; w<=16; w+=winc[bdlo])
+         {
+            /* First test all the 'size' images against the sequential
+            * reader using libpng to deinterlace (where required.)  This
+            * validates the write side of libpng.  There are four possibilities
+            * to validate.
+            */
+            standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+               0/*palette*/, PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/,
+               pm->use_update_info);
 
-         if (fail(pm))
-            return 0;
+            if (fail(pm))
+               return 0;
 
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
-            PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/,
-            pm->use_update_info);
+            standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+               0/*palette*/, PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/,
+               pm->use_update_info);
 
-         if (fail(pm))
-            return 0;
+            if (fail(pm))
+               return 0;
 
-         /* Now validate the interlaced read side - do_interlace true,
-          * in the progressive case this does actually make a difference
-          * to the code used in the non-interlaced case too.
-          */
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
-            PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/,
-            pm->use_update_info);
+            /* Now validate the interlaced read side - do_interlace true,
+            * in the progressive case this does actually make a difference
+            * to the code used in the non-interlaced case too.
+            */
+            standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+               0/*palette*/, PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/,
+               pm->use_update_info);
 
-         if (fail(pm))
-            return 0;
+            if (fail(pm))
+               return 0;
 
-#     if CAN_WRITE_INTERLACE
-         /* Validate the pngvalid code itself: */
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
-            PNG_INTERLACE_ADAM7, w, h, 1), 1/*do_interlace*/,
-            pm->use_update_info);
+#        if CAN_WRITE_INTERLACE
+            /* Validate the pngvalid code itself: */
+            standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+               0/*palette*/, PNG_INTERLACE_ADAM7, w, h, 1), 1/*do_interlace*/,
+               pm->use_update_info);
 
-         if (fail(pm))
-            return 0;
-#     endif
+            if (fail(pm))
+               return 0;
+#        endif
+         }
       }
    }
 
@@ -5926,45 +5932,48 @@ test_size(png_modifier* const pm, png_byte const colour_type,
    {
       png_uint_32 h, w;
 
-      for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo])
+      for (h=1; h<=16; h+=hinc[bdlo])
       {
-#     ifdef PNG_READ_INTERLACING_SUPPORTED
-         /* Test with pngvalid generated interlaced images first; we have
-          * already verify these are ok (unless pngvalid has self-consistent
-          * read/write errors, which is unlikely), so this detects errors in the
-          * read side first:
-          */
-#     if CAN_WRITE_INTERLACE
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
-            PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/,
-            pm->use_update_info);
+         for (w=1; w<=16; w+=winc[bdlo])
+         {
+#        ifdef PNG_READ_INTERLACING_SUPPORTED
+            /* Test with pngvalid generated interlaced images first; we have
+            * already verify these are ok (unless pngvalid has self-consistent
+            * read/write errors, which is unlikely), so this detects errors in
+            * the read side first:
+            */
+#        if CAN_WRITE_INTERLACE
+            standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+               0/*palette*/, PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/,
+               pm->use_update_info);
 
-         if (fail(pm))
-            return 0;
-#     endif
-#     endif /* READ_INTERLACING */
+            if (fail(pm))
+               return 0;
+#        endif
+#        endif /* READ_INTERLACING */
 
-#     ifdef PNG_WRITE_INTERLACING_SUPPORTED
-         /* Test the libpng write side against the pngvalid read side: */
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
-            PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/,
-            pm->use_update_info);
+#        ifdef PNG_WRITE_INTERLACING_SUPPORTED
+            /* Test the libpng write side against the pngvalid read side: */
+            standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+               0/*palette*/, PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/,
+               pm->use_update_info);
 
-         if (fail(pm))
-            return 0;
-#     endif
+            if (fail(pm))
+               return 0;
+#        endif
 
-#     ifdef PNG_READ_INTERLACING_SUPPORTED
-#     ifdef PNG_WRITE_INTERLACING_SUPPORTED
-         /* Test both together: */
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
-            PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/,
-            pm->use_update_info);
+#        ifdef PNG_READ_INTERLACING_SUPPORTED
+#        ifdef PNG_WRITE_INTERLACING_SUPPORTED
+            /* Test both together: */
+            standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+               0/*palette*/, PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/,
+               pm->use_update_info);
 
-         if (fail(pm))
-            return 0;
-#     endif
-#     endif /* READ_INTERLACING */
+            if (fail(pm))
+               return 0;
+#        endif
+#        endif /* READ_INTERLACING */
+         }
       }
    }
 
@@ -6077,12 +6086,12 @@ 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
@@ -6100,7 +6109,7 @@ 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;
@@ -6431,8 +6440,8 @@ 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)
@@ -6710,7 +6719,7 @@ transform_range_check(png_const_structp pp, unsigned int r, unsigned int g,
    unsigned int out, png_byte sample_depth, double err, double limit,
    const char *name, double digitization_error)
 {
-   /* Compare the scaled, digitzed, values of our local calculation (in+-err)
+   /* Compare the scaled, digitized, values of our local calculation (in+-err)
     * with the digitized values libpng produced;  'sample_depth' is the actual
     * digitization depth of the libpng output colors (the bit depth except for
     * palette images where it is always 8.)  The check on 'err' is to detect
@@ -6755,19 +6764,19 @@ 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;
@@ -6928,7 +6937,7 @@ 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;
@@ -7634,7 +7643,7 @@ image_transform_png_set_rgb_to_gray_ini(const image_transform *this,
 
    else
    {
-      /* The default (built in) coeffcients, as above: */
+      /* The default (built in) coefficients, as above: */
 #     if PNG_LIBPNG_VER < 10700
          data.red_coefficient = 6968 / 32768.;
          data.green_coefficient = 23434 / 32768.;
@@ -7763,7 +7772,7 @@ 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 +7913,10 @@ 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 ?
@@ -8001,7 +8010,7 @@ 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) +
@@ -8625,7 +8634,7 @@ 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 +8701,7 @@ 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 +8892,7 @@ 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);
@@ -9056,7 +9065,7 @@ image_transform_reset_count(void)
 static int
 image_transform_test_counter(png_uint_32 counter, unsigned int max)
 {
-   /* Test the list to see if there is any point contining, given a current
+   /* Test the list to see if there is any point continuing, given a current
     * counter and a 'max' value.
     */
    image_transform *next = image_transform_first;
@@ -9298,12 +9307,12 @@ 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 +9360,7 @@ 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 +9434,7 @@ 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 +9596,14 @@ 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;
 
@@ -10160,13 +10169,13 @@ 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
@@ -10207,11 +10216,11 @@ 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 +10268,9 @@ 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 +10279,7 @@ 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 +10404,14 @@ 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 +10615,11 @@ 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];
@@ -10648,16 +10657,21 @@ static void perform_gamma_transform_tests(png_modifier *pm)
    {
       unsigned int i, j;
 
-      for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j)
-         if (i != j)
+      for (i=0; i<pm->ngamma_tests; ++i)
+      {
+         for (j=0; j<pm->ngamma_tests; ++j)
          {
-            gamma_transform_test(pm, colour_type, bit_depth, palette_number,
-               pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], 0/*sBIT*/,
-               pm->use_input_precision, 0 /*do not scale16*/);
+            if (i != j)
+            {
+               gamma_transform_test(pm, colour_type, bit_depth, palette_number,
+                  pm->interlace_type, 1/pm->gammas[i], pm->gammas[j],
+                  0/*sBIT*/, pm->use_input_precision, 0/*do not scale16*/);
 
-            if (fail(pm))
-               return;
+               if (fail(pm))
+                  return;
+            }
          }
+      }
    }
 }
 
@@ -10686,14 +10700,17 @@ static void perform_gamma_sbit_tests(png_modifier *pm)
          {
             unsigned int j;
 
-            for (j=0; j<pm->ngamma_tests; ++j) if (i != j)
+            for (j=0; j<pm->ngamma_tests; ++j)
             {
-               gamma_transform_test(pm, colour_type, bit_depth, npalette,
-                  pm->interlace_type, 1/pm->gammas[i], pm->gammas[j],
-                  sbit, pm->use_input_precision_sbit, 0 /*scale16*/);
+               if (i != j)
+               {
+                  gamma_transform_test(pm, colour_type, bit_depth, npalette,
+                     pm->interlace_type, 1/pm->gammas[i], pm->gammas[j],
+                     sbit, pm->use_input_precision_sbit, 0 /*scale16*/);
 
-               if (fail(pm))
-                  return;
+                  if (fail(pm))
+                     return;
+               }
             }
          }
       }
@@ -10767,12 +10784,12 @@ 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;
@@ -10945,14 +10962,17 @@ perform_gamma_composition_tests(png_modifier *pm, int do_background,
       unsigned int i, j;
 
       /* Don't skip the i==j case here - it's relevant. */
-      for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j)
+      for (i=0; i<pm->ngamma_tests; ++i)
       {
-         gamma_composition_test(pm, colour_type, bit_depth, palette_number,
-            pm->interlace_type, 1/pm->gammas[i], pm->gammas[j],
-            pm->use_input_precision, do_background, expand_16);
+         for (j=0; j<pm->ngamma_tests; ++j)
+         {
+            gamma_composition_test(pm, colour_type, bit_depth, palette_number,
+               pm->interlace_type, 1/pm->gammas[i], pm->gammas[j],
+               pm->use_input_precision, do_background, expand_16);
 
-         if (fail(pm))
-            return;
+            if (fail(pm))
+               return;
+         }
       }
    }
 }
@@ -11055,7 +11075,7 @@ perform_gamma_test(png_modifier *pm, int summary)
          pm->calculations_use_input_precision = 0;
 
       if (summary)
-         summarize_gamma_errors(pm, 0/*who*/, 1/*low bit depth*/, 1/*indexed*/);
+         summarize_gamma_errors(pm, NULL/*who*/, 1/*low bit depth*/, 1/*indexed*/);
 
       if (fail(pm))
          return;
@@ -11181,8 +11201,10 @@ png_pass_start_row(int pass)
 {
    int x, y;
    ++pass;
-   for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass)
-      return y;
+   for (y=0; y<8; ++y)
+      for (x=0; x<8; ++x)
+         if (adam7[y][x] == pass)
+            return y;
    return 0xf;
 }
 
@@ -11191,8 +11213,10 @@ png_pass_start_col(int pass)
 {
    int x, y;
    ++pass;
-   for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass)
-      return x;
+   for (x=0; x<8; ++x)
+      for (y=0; y<8; ++y)
+         if (adam7[y][x] == pass)
+            return x;
    return 0xf;
 }
 
@@ -11201,18 +11225,24 @@ png_pass_row_shift(int pass)
 {
    int x, y, base=(-1), inc=8;
    ++pass;
-   for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass)
+   for (y=0; y<8; ++y)
    {
-      if (base == (-1))
-         base = y;
-      else if (base == y)
-         {}
-      else if (inc == y-base)
-         base=y;
-      else if (inc == 8)
-         inc = y-base, base=y;
-      else if (inc != y-base)
-         return 0xff; /* error - more than one 'inc' value! */
+      for (x=0; x<8; ++x)
+      {
+         if (adam7[y][x] == pass)
+         {
+            if (base == (-1))
+               base = y;
+            else if (base == y)
+               {}
+            else if (inc == y-base)
+               base=y;
+            else if (inc == 8)
+               inc = y-base, base=y;
+            else if (inc != y-base)
+               return 0xff; /* error - more than one 'inc' value! */
+         }
+      }
    }
 
    if (base == (-1)) return 0xfe; /* error - no row in pass! */
@@ -11235,18 +11265,24 @@ png_pass_col_shift(int pass)
 {
    int x, y, base=(-1), inc=8;
    ++pass;
-   for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass)
+   for (x=0; x<8; ++x)
    {
-      if (base == (-1))
-         base = x;
-      else if (base == x)
-         {}
-      else if (inc == x-base)
-         base=x;
-      else if (inc == 8)
-         inc = x-base, base=x;
-      else if (inc != x-base)
-         return 0xff; /* error - more than one 'inc' value! */
+      for (y=0; y<8; ++y)
+      {
+         if (adam7[y][x] == pass)
+         {
+            if (base == (-1))
+               base = x;
+            else if (base == x)
+               {}
+            else if (inc == x-base)
+               base=x;
+            else if (inc == 8)
+               inc = x-base, base=x;
+            else if (inc != x-base)
+               return 0xff; /* error - more than one 'inc' value! */
+         }
+      }
    }
 
    if (base == (-1)) return 0xfe; /* error - no row in pass! */
@@ -11310,8 +11346,9 @@ png_row_in_interlace_pass(png_uint_32 y, int pass)
    int x;
    y &= 7;
    ++pass;
-   for (x=0; x<8; ++x) if (adam7[y][x] == pass)
-      return 1;
+   for (x=0; x<8; ++x)
+      if (adam7[y][x] == pass)
+         return 1;
 
    return 0;
 }
@@ -11323,8 +11360,9 @@ png_col_in_interlace_pass(png_uint_32 x, int pass)
    int y;
    x &= 7;
    ++pass;
-   for (y=0; y<8; ++y) if (adam7[y][x] == pass)
-      return 1;
+   for (y=0; y<8; ++y)
+      if (adam7[y][x] == pass)
+         return 1;
 
    return 0;
 }
@@ -11338,11 +11376,17 @@ png_pass_rows(png_uint_32 height, int pass)
 
    height &= 7;
    ++pass;
-   for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass)
+   for (y=0; y<8; ++y)
    {
-      rows += tiles;
-      if (y < height) ++rows;
-      break; /* i.e. break the 'x', column, loop. */
+      for (x=0; x<8; ++x)
+      {
+         if (adam7[y][x] == pass)
+         {
+            rows += tiles;
+            if (y < height) ++rows;
+            break; /* i.e. break the 'x', column, loop. */
+         }
+      }
    }
 
    return rows;
@@ -11357,11 +11401,17 @@ png_pass_cols(png_uint_32 width, int pass)
 
    width &= 7;
    ++pass;
-   for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass)
+   for (x=0; x<8; ++x)
    {
-      cols += tiles;
-      if (x < width) ++cols;
-      break; /* i.e. break the 'y', row, loop. */
+      for (y=0; y<8; ++y)
+      {
+         if (adam7[y][x] == pass)
+         {
+            cols += tiles;
+            if (x < width) ++cols;
+            break; /* i.e. break the 'y', row, loop. */
+         }
+      }
    }
 
    return cols;
@@ -11718,7 +11768,7 @@ int main(int argc, char **argv)
 
    /* The following allows results to pass if they correspond to anything in the
     * transformed range [input-.5,input+.5]; this is is required because of the
-    * way libpng treates the 16_TO_8 flag when building the gamma tables in
+    * way libpng treats the 16_TO_8 flag when building the gamma tables in
     * releases up to 1.6.0.
     *
     * TODO: review this
@@ -11809,21 +11859,21 @@ int main(int argc, char **argv)
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
       else if (strncmp(*argv, "--transform-disable=",
          sizeof "--transform-disable") == 0)
-         {
+      {
          pm.test_transform = 1;
          transform_disable(*argv + sizeof "--transform-disable");
-         }
+      }
 
       else if (strncmp(*argv, "--transform-enable=",
          sizeof "--transform-enable") == 0)
-         {
+      {
          pm.test_transform = 1;
          transform_enable(*argv + sizeof "--transform-enable");
-         }
+      }
 #endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
       else if (strcmp(*argv, "--gamma") == 0)
-         {
+      {
          /* Just do two gamma tests here (2.2 and linear) for speed: */
          pm.ngamma_tests = 2U;
          pm.test_gamma_threshold = 1;
@@ -11832,7 +11882,7 @@ int main(int argc, char **argv)
          pm.test_gamma_scale16 = 1;
          pm.test_gamma_background = 1; /* composition */
          pm.test_gamma_alpha_mode = 1;
-         }
+      }
 
       else if (strcmp(*argv, "--nogamma") == 0)
          pm.ngamma_tests = 0;

contrib/libtests/readpng.c

@@ -1,9 +1,8 @@
+
 /* readpng.c
  *
  * Copyright (c) 2013 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h

contrib/libtests/tarith.c

@@ -1,10 +1,9 @@
 
 /* tarith.c
  *
+ * Copyright (c) 2021 Cosmin Truta
  * Copyright (c) 2011-2013 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.0 [February 14, 2013]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -88,6 +87,7 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
    int    minorarith = 0;
 
    while (--argc > 0)
+   {
       if (strcmp(*++argv, "-a") == 0)
          showall = 1;
       else if (strcmp(*argv, "-e") == 0 && argc > 0)
@@ -105,6 +105,7 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
          fprintf(stderr, "unknown argument %s\n", *argv);
          return 1;
       }
+   }
 
    do
    {
@@ -130,8 +131,8 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
        */
       if (buffer[precision+7] != 71)
       {
-         fprintf(stderr, "%g[%d] -> '%s'[%lu] buffer overflow\n", test,
-            precision, buffer, (unsigned long)strlen(buffer));
+         fprintf(stderr, "%g[%d] -> '%s'[%lu] buffer overflow\n",
+            test, precision, buffer, (unsigned long)strlen(buffer));
          failed = 1;
       }
 
@@ -146,16 +147,16 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
          if (test >= 0 && strcmp(buffer, "inf") ||
              test <  0 && strcmp(buffer, "-inf"))
          {
-            fprintf(stderr, "%g[%d] -> '%s' but expected 'inf'\n", test,
-               precision, buffer);
+            fprintf(stderr, "%g[%d] -> '%s' but expected 'inf'\n",
+               test, precision, buffer);
             failed = 1;
          }
       }
       else if (!png_check_fp_number(buffer, precision+10, &state, &index) ||
           buffer[index] != 0)
       {
-         fprintf(stderr, "%g[%d] -> '%s' but has bad format ('%c')\n", test,
-         precision, buffer, buffer[index]);
+         fprintf(stderr, "%g[%d] -> '%s' but has bad format ('%c')\n",
+            test, precision, buffer, buffer[index]);
          failed = 1;
       }
       else if (PNG_FP_IS_NEGATIVE(state) && !(test < 0))
@@ -187,7 +188,7 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
          /* Check the result against the original. */
          double out = atof(buffer);
          double change = fabs((out - test)/test);
-         double allow = .5/pow(10,
+         double allow = .5 / pow(10,
             (precision >= DBL_DIG) ? DBL_DIG-1 : precision-1);
 
          /* NOTE: if you hit this error case are you compiling with gcc
@@ -257,8 +258,9 @@ skip:
    }
    while (--count);
 
-   printf("Tested %d finite values, %d non-finite, %d OK (%d failed) %d minor "
-      "arithmetic errors\n", finite, nonfinite, ok, failcount, minorarith);
+   printf("Tested %d finite values, %d non-finite, %d OK (%d failed) "
+      "%d minor arithmetic errors\n",
+      finite, nonfinite, ok, failcount, minorarith);
    printf(" Error with >=%d digit precision %.2f%%\n", DBL_DIG, max_abs);
    printf(" Error with < %d digit precision %.2f%%\n", DBL_DIG, max);
 
@@ -331,8 +333,8 @@ static int check_one_character(checkfp_command *co, checkfp_control c, int ch)
     */
    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;
@@ -371,8 +373,8 @@ static int check_one_character(checkfp_command *co, checkfp_control c, int ch)
    /* This should never fail (it's a serious bug if it does): */
    if (index != 0 && index != 1)
    {
-      fprintf(stderr, "%s: read beyond end of string (%lu)\n", co->number,
-         (unsigned long)index);
+      fprintf(stderr, "%s: read beyond end of string (%lu)\n",
+         co->number, (unsigned long)index);
       return 0;
    }
 
@@ -503,8 +505,8 @@ static int check_one_character(checkfp_command *co, checkfp_control c, int ch)
       if (number_is_valid != c.number_was_valid)
       {
          fprintf(stderr,
-            "%s: character '%c' [0x%.2x] changed number validity\n", co->number,
-            ch, ch);
+            "%s: character '%c' [0x%.2x] changed number validity\n",
+            co->number, ch, ch);
          return 0;
       }
 
@@ -521,10 +523,13 @@ static int check_all_characters(checkfp_command *co, checkfp_control c)
 {
    int ch;
 
-   if (c.cnumber+4 < sizeof co->number) for (ch=0; ch<256; ++ch)
+   if (c.cnumber+4 < sizeof co->number)
    {
-      if (!check_one_character(co, c, ch))
-         return 0;
+      for (ch=0; ch<256; ++ch)
+      {
+         if (!check_one_character(co, c, ch))
+            return 0;
+      }
    }
 
    return 1;
@@ -539,10 +544,13 @@ static int check_some_characters(checkfp_command *co, checkfp_control c,
 
    if (c.cnumber+4 < sizeof co->number && c.limit >= 0)
    {
-      if (c.limit > 0) for (i=0; tests[i]; ++i)
+      if (c.limit > 0)
       {
-         if (!check_one_character(co, c, tests[i]))
-               return 0;
+         for (i=0; tests[i]; ++i)
+         {
+            if (!check_one_character(co, c, tests[i]))
+                  return 0;
+         }
       }
 
       /* At the end check all the characters. */
@@ -616,10 +624,10 @@ int validation_muldiv(int count, int argc, char **argv)
    png_int_32 times, div;
 
    while (--argc > 0)
-      {
-         fprintf(stderr, "unknown argument %s\n", *++argv);
-         return 1;
-      }
+   {
+      fprintf(stderr, "unknown argument %s\n", *++argv);
+      return 1;
+   }
 
    /* Find out about the random number generator. */
    randbuffer = RAND_MAX;
@@ -687,25 +695,25 @@ int validation_muldiv(int count, int argc, char **argv)
         ok = 0, ++overflow, fpround = fp/*misleading*/;
 
       if (verbose)
-         fprintf(stderr, "TEST %d * %d / %d -> %lld (%s)\n", a, times, div,
-            fp, ok ? "ok" : "overflow");
+         fprintf(stderr, "TEST %d * %d / %d -> %lld (%s)\n",
+            a, times, div, fp, ok ? "ok" : "overflow");
 
       ++tested;
       if (png_muldiv(&result, a, times, div) != ok)
       {
          ++error;
          if (ok)
-             fprintf(stderr, "%d * %d / %d -> overflow (expected %lld)\n", a,
-                times, div, fp);
+             fprintf(stderr, "%d * %d / %d -> overflow (expected %lld)\n",
+                a, times, div, fp);
          else
-             fprintf(stderr, "%d * %d / %d -> %d (expected overflow %lld)\n", a,
-                times, div, result, fp);
+             fprintf(stderr, "%d * %d / %d -> %d (expected overflow %lld)\n",
+                a, times, div, result, fp);
       }
       else if (ok && result != fpround)
       {
          ++error;
-         fprintf(stderr, "%d * %d / %d -> %d not %lld\n", a, times, div, result,
-            fp);
+         fprintf(stderr, "%d * %d / %d -> %d not %lld\n",
+            a, times, div, result, fp);
       }
       else
          ++passed;
@@ -721,8 +729,8 @@ int validation_muldiv(int count, int argc, char **argv)
    }
    while (--count > 0);
 
-   printf("%d tests including %d overflows, %d passed, %d failed (%d 64-bit "
-      "errors)\n", tested, overflow, passed, error, error64);
+   printf("%d tests including %d overflows, %d passed, %d failed "
+      "(%d 64-bit errors)\n", tested, overflow, passed, error, error64);
    return 0;
 }
 
@@ -821,8 +829,9 @@ int validation_gamma(int argc, char **argv)
          {
             if (error > .68) /* By experiment error is less than .68 */
             {
-               fprintf(stderr, "16-bit log error: %d: got %u, expected %f"
-                  " error: %f\n", i, png_log16bit(i), correct, error);
+               fprintf(stderr,
+                  "16-bit log error: %d: got %u, expected %f error: %f\n",
+                  i, png_log16bit(i), correct, error);
             }
          }
       }
@@ -841,8 +850,9 @@ int validation_gamma(int argc, char **argv)
             maxerr = fabs(error);
          if (fabs(error) > 1883) /* By experiment. */
          {
-            fprintf(stderr, "32-bit exp error: %d: got %u, expected %f"
-                  " error: %f\n", i, png_exp(i), correct, error);
+            fprintf(stderr,
+               "32-bit exp error: %d: got %u, expected %f error: %f\n",
+               i, png_exp(i), correct, error);
          }
       }
 
@@ -859,8 +869,9 @@ int validation_gamma(int argc, char **argv)
             maxerr = fabs(error);
          if (fabs(error) > .50002) /* By experiment */
          {
-            fprintf(stderr, "8-bit exp error: %d: got %u, expected %f"
-                  " error: %f\n", i, png_exp8bit(i), correct, error);
+            fprintf(stderr,
+               "8-bit exp error: %d: got %u, expected %f error: %f\n",
+               i, png_exp8bit(i), correct, error);
          }
       }
 
@@ -877,8 +888,9 @@ int validation_gamma(int argc, char **argv)
             maxerr = fabs(error);
          if (fabs(error) > .524) /* By experiment */
          {
-            fprintf(stderr, "16-bit exp error: %d: got %u, expected %f"
-                  " error: %f\n", i, png_exp16bit(i), correct, error);
+            fprintf(stderr,
+               "16-bit exp error: %d: got %u, expected %f error: %f\n",
+               i, png_exp16bit(i), correct, error);
          }
       }
 
@@ -940,7 +952,7 @@ int validation_gamma(int argc, char **argv)
 
 /**************************** VALIDATION TESTS ********************************/
 /* Various validation routines are included herein, they require some
- * definition for png_warning and png_error, seetings of VALIDATION:
+ * definition for png_warning and png_error, settings of VALIDATION:
  *
  * 1: validates the ASCII to floating point conversions
  * 2: validates png_muldiv

contrib/libtests/timepng.c

@@ -1,9 +1,8 @@
+
 /* timepng.c
  *
  * Copyright (c) 2013,2016 John Cunningham Bowler
  *
- * 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
@@ -528,7 +527,7 @@ int main(int argc, char **argv)
       }
    }
 
-   else if (nfiles == 0) /* Read from stdin withoout --dissemble */
+   else if (nfiles == 0) /* Read from stdin without --dissemble */
    {
       char filename[FILENAME_MAX+1];
 

contrib/mips-mmi/linux.c

@@ -0,0 +1,142 @@
+
+/* contrib/mips-mmi/linux.c
+ *
+ * Copyright (c) 2024 Cosmin Truta
+ * Written by guxiwei, 2023
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/auxv.h>
+
+/*
+ * parse_r var, r - Helper assembler macro for parsing register names.
+ *
+ * This converts the register name in $n form provided in \r to the
+ * corresponding register number, which is assigned to the variable \var. It is
+ * needed to allow explicit encoding of instructions in inline assembly where
+ * registers are chosen by the compiler in $n form, allowing us to avoid using
+ * fixed register numbers.
+ *
+ * It also allows newer instructions (not implemented by the assembler) to be
+ * transparently implemented using assembler macros, instead of needing separate
+ * cases depending on toolchain support.
+ *
+ * Simple usage example:
+ * __asm__ __volatile__("parse_r __rt, %0\n\t"
+ *                      ".insn\n\t"
+ *                      "# di    %0\n\t"
+ *                      ".word   (0x41606000 | (__rt << 16))"
+ *                      : "=r" (status);
+ */
+
+/* Match an individual register number and assign to \var */
+#define _IFC_REG(n)                                \
+        ".ifc        \\r, $" #n "\n\t"             \
+        "\\var        = " #n "\n\t"                \
+        ".endif\n\t"
+
+__asm__(".macro        parse_r var r\n\t"
+        "\\var        = -1\n\t"
+        _IFC_REG(0)  _IFC_REG(1)  _IFC_REG(2)  _IFC_REG(3)
+        _IFC_REG(4)  _IFC_REG(5)  _IFC_REG(6)  _IFC_REG(7)
+        _IFC_REG(8)  _IFC_REG(9)  _IFC_REG(10) _IFC_REG(11)
+        _IFC_REG(12) _IFC_REG(13) _IFC_REG(14) _IFC_REG(15)
+        _IFC_REG(16) _IFC_REG(17) _IFC_REG(18) _IFC_REG(19)
+        _IFC_REG(20) _IFC_REG(21) _IFC_REG(22) _IFC_REG(23)
+        _IFC_REG(24) _IFC_REG(25) _IFC_REG(26) _IFC_REG(27)
+        _IFC_REG(28) _IFC_REG(29) _IFC_REG(30) _IFC_REG(31)
+        ".iflt        \\var\n\t"
+        ".error        \"Unable to parse register name \\r\"\n\t"
+        ".endif\n\t"
+        ".endm");
+
+#define HWCAP_LOONGSON_CPUCFG (1 << 14)
+
+static int cpucfg_available(void)
+{
+    return getauxval(AT_HWCAP) & HWCAP_LOONGSON_CPUCFG;
+}
+
+static int strstart(const char *str, const char *pfx, const char **ptr)
+{
+    while (*pfx && *pfx == *str) {
+        pfx++;
+        str++;
+    }
+    if (!*pfx && ptr)
+        *ptr = str;
+    return !*pfx;
+}
+
+/* Most toolchains have no CPUCFG support yet */
+static uint32_t read_cpucfg(uint32_t reg)
+{
+        uint32_t __res;
+
+        __asm__ __volatile__(
+                "parse_r __res,%0\n\t"
+                "parse_r reg,%1\n\t"
+                ".insn \n\t"
+                ".word (0xc8080118 | (reg << 21) | (__res << 11))\n\t"
+                :"=r"(__res)
+                :"r"(reg)
+                :
+                );
+        return __res;
+}
+
+#define LOONGSON_CFG1 0x1
+
+#define LOONGSON_CFG1_MMI    (1 << 4)
+
+static int cpu_flags_cpucfg(void)
+{
+    int flags = 0;
+    uint32_t cfg1 = read_cpucfg(LOONGSON_CFG1);
+
+    if (cfg1 & LOONGSON_CFG1_MMI)
+        flags = 1;
+
+    return flags;
+}
+
+static int cpu_flags_cpuinfo(void)
+{
+    FILE *f = fopen("/proc/cpuinfo", "r");
+    char buf[200];
+    int flags = 0;
+
+    if (!f)
+        return flags;
+
+    while (fgets(buf, sizeof(buf), f)) {
+        /* Legacy kernel may not export MMI in ASEs implemented */
+        if (strstart(buf, "cpu model", NULL)) {
+            if (strstr(buf, "Loongson-3 "))
+                flags = 1;
+            break;
+        }
+        if (strstart(buf, "ASEs implemented", NULL)) {
+            if (strstr(buf, " loongson-mmi"))
+                flags = 1;
+            break;
+        }
+    }
+    fclose(f);
+    return flags;
+}
+
+static int png_have_mmi()
+{
+    if (cpucfg_available())
+        return cpu_flags_cpucfg();
+    else
+        return cpu_flags_cpuinfo();
+    return 0;
+}

contrib/mips-msa/linux.c

@@ -1,64 +1,55 @@
+
 /* contrib/mips-msa/linux.c
  *
+ * Copyright (c) 2020-2023 Cosmin Truta
  * Copyright (c) 2016 Glenn Randers-Pehrson
  * Written by Mandar Sahastrabuddhe, 2016.
- * Last changed in libpng 1.6.25beta03 [August 29, 2016]
+ * Updated by Sui Jingfeng, 2021.
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  *
- * SEE contrib/mips-msa/README before reporting bugs
+ * On Linux, png_have_msa is implemented by reading the pseudo-file
+ * "/proc/self/auxv".
+ *
+ * See contrib/mips-msa/README before reporting bugs.
  *
  * STATUS: SUPPORTED
  * BUG REPORTS: png-mng-implement@sourceforge.net
- *
- * png_have_msa 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 <elf.h>
+#include <fcntl.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 static int
 png_have_msa(png_structp png_ptr)
 {
-   FILE *f = fopen("/proc/cpuinfo", "rb");
+   Elf64_auxv_t aux;
+   int fd;
+   int has_msa = 0;
 
-   char *string = "msa";
-   char word[10];
-
-   if (f != NULL)
+   fd = open("/proc/self/auxv", O_RDONLY);
+   if (fd >= 0)
    {
-      while(!feof(f))
+      while (read(fd, &aux, sizeof(Elf64_auxv_t)) == sizeof(Elf64_auxv_t))
       {
-         int ch = fgetc(f);
-         static int i = 0;
-
-         while(!(ch <= 32))
+         if (aux.a_type == AT_HWCAP)
          {
-            word[i++] = ch;
-            ch = fgetc(f);
+            uint64_t hwcap = aux.a_un.a_val;
+
+            has_msa = (hwcap >> 1) & 1;
+            break;
          }
-
-         int val = strcmp(string, word);
-
-         if (val == 0)
-            return 1;
-
-         i = 0;
-         memset(word, 0, 10);
       }
-
-      fclose(f);
+      close(fd);
    }
 #ifdef PNG_WARNINGS_SUPPORTED
    else
-      png_warning(png_ptr, "/proc/cpuinfo open failed");
+      png_warning(png_ptr, "/proc/self/auxv open failed");
 #endif
-   return 0;
+
+   return has_msa;
 }

contrib/oss-fuzz/README.txt

@@ -1,4 +1,3 @@
-Last changed in libpng 1.6.33 [September 28, 2017]
 Copyright (c) 2017 Glenn Randers-Pehrson
 
 This code is released under the libpng license.

contrib/oss-fuzz/build.sh

@@ -1,4 +1,5 @@
 #!/bin/bash -eu
+
 # Copyright 2017-2018 Glenn Randers-Pehrson
 # Copyright 2016 Google Inc.
 #
@@ -14,8 +15,6 @@
 # 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").

contrib/oss-fuzz/libpng_read_fuzzer.cc

@@ -5,8 +5,6 @@
 // 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,
@@ -17,6 +15,7 @@
 
 #include <stddef.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include <vector>
@@ -60,7 +59,7 @@ struct PngObjectHandler {
       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) 
+    else if (info_ptr)
       png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
     else
       png_destroy_read_struct(&png_ptr, nullptr, nullptr);
@@ -78,6 +77,22 @@ void user_read_data(png_structp png_ptr, png_bytep data, size_t length) {
   buf_state->data += length;
 }
 
+void* limited_malloc(png_structp, png_alloc_size_t size) {
+  // libpng may allocate large amounts of memory that the fuzzer reports as
+  // an error. In order to silence these errors, make libpng fail when trying
+  // to allocate a large amount. This allocator used to be in the Chromium
+  // version of this fuzzer.
+  // This number is chosen to match the default png_user_chunk_malloc_max.
+  if (size > 8000000)
+    return nullptr;
+
+  return malloc(size);
+}
+
+void default_free(png_structp, png_voidp ptr) {
+  return free(ptr);
+}
+
 static const int kPngHeaderSize = 8;
 
 // Entry point for LibFuzzer.
@@ -118,6 +133,9 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     return 0;
   }
 
+  // Use a custom allocator that fails for large allocations to avoid OOM.
+  png_set_mem_fn(png_handler.png_ptr, nullptr, limited_malloc, default_free);
+
   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);

contrib/pngminus/.gitignore

@@ -0,0 +1,11 @@
+# Compiled executables
+png2pnm
+png2pnm.exe
+png2pnm-static*
+pnm2png
+pnm2png.exe
+pnm2png-static*
+
+# Test artifacts
+*.png
+*.p[abgnp]m

contrib/pngminus/CHANGES.txt

@@ -0,0 +1,14 @@
+
+pnm2png / png2pnm --- conversion from PBM/PGM/PPM-file to PNG-file
+copyright (C) 1999-2019 by Willem van Schaik <willem at schaik dot com>
+
+version 1.0 - 1999.10.15 - First version.
+        1.1 - 2015.07.29 - Fix memory leaks (Glenn Randers-Pehrson)
+        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)
+        1.5 - 2018.08.05 - Fix buffer overflow in tokenizer (Cosmin Truta)
+        1.6 - 2018.08.05 - Improve portability and fix style (Cosmin Truta)
+        1.7 - 2019.01.22 - Change license to MIT (Willem van Schaik)
+        1.8 - 2024.01.09 - Fix, improve, modernize (Cosmin Truta)

contrib/pngminus/CMakeLists.txt

@@ -0,0 +1,41 @@
+# Copyright (c) 2018-2024 Cosmin Truta
+#
+# This software is released under the MIT license. For conditions of
+# distribution and use, see the LICENSE file part of this package.
+
+cmake_minimum_required(VERSION 3.5)
+
+project(PNGMINUS C)
+
+option(PNGMINUS_USE_SYSTEM_PNG
+       "Use the libpng build found in the system" OFF)
+
+add_executable(png2pnm png2pnm.c)
+add_executable(pnm2png pnm2png.c)
+
+if(PNGMINUS_USE_SYSTEM_PNG)
+    # Use the system libpng.
+    find_package(PNG REQUIRED)
+    target_link_libraries(png2pnm PRIVATE PNG::PNG)
+    target_link_libraries(pnm2png PRIVATE PNG::PNG)
+else()
+    # Build and use the internal libpng.
+    # Configure libpng for static linking, to produce single-file executables.
+    set(PNG_STATIC ON
+        CACHE STRING "Build the internal libpng as a static library" FORCE)
+    set(PNG_SHARED OFF
+        CACHE STRING "Build the internal libpng as a shared library" FORCE)
+    set(PNG_FRAMEWORK OFF
+        CACHE STRING "Build the internal libpng as a framework bundle" FORCE)
+    add_subdirectory(../.. libpng)
+    target_include_directories(png2pnm PRIVATE
+        "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/../..>"
+        "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/libpng>"
+    )
+    target_include_directories(pnm2png PRIVATE
+        "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/../..>"
+        "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/libpng>"
+    )
+    target_link_libraries(png2pnm PRIVATE png_static)
+    target_link_libraries(pnm2png PRIVATE png_static)
+endif()

contrib/pngminus/LICENSE.txt

@@ -0,0 +1,22 @@
+
+pnm2png / png2pnm --- conversion from PBM/PGM/PPM-file to PNG-file
+
+copyright (C) 1999-2019 by Willem van Schaik <willem at schaik dot com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+The software is provided "as is", without warranty of any kind, express or
+implied, including but not limited to the warranties of merchantability,
+fitness for a particular purpose and noninfringement. In no event shall the
+authors or copyright holders be liable for any claim, damages or other
+liability, whether in an action of contract, tort or otherwise, arising from,
+out of or in connection with the software or the use or other dealings in the
+software.

contrib/pngminus/Makefile

@@ -0,0 +1,62 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# Linux / Unix
+
+#CC = cc
+CC = gcc
+LD = $(CC)
+
+RM = rm -f
+
+PNGINC = -I../..
+PNGLIB_SHARED = -L../.. -lpng
+PNGLIB_STATIC = ../../libpng.a
+
+# Uncomment the following if you have a custom zlib build at ../../../zlib
+#ZINC = -I../../../zlib
+#ZLIB_SHARED = -L../../../zlib -lz
+#ZLIB_STATIC = ../../../zlib/libz.a
+
+# Use the system zlib otherwise
+ZLIB_SHARED = -lz
+ZLIB_STATIC = -lz
+
+CPPFLAGS = $(PNGINC) $(ZINC)
+CFLAGS =
+LDFLAGS =
+LIBS_SHARED = $(PNGLIB_SHARED) $(ZLIB_SHARED)
+LIBS_STATIC = $(PNGLIB_STATIC) $(ZLIB_STATIC)
+
+EXEEXT =
+#EXEEXT = .exe
+
+# dependencies
+
+all: png2pnm$(EXEEXT) pnm2png$(EXEEXT) png2pnm-static$(EXEEXT) pnm2png-static$(EXEEXT)
+
+png2pnm.o: png2pnm.c
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) png2pnm.c
+
+pnm2png.o: pnm2png.c
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) pnm2png.c
+
+png2pnm$(EXEEXT): png2pnm.o
+	$(LD) $(LDFLAGS) -o png2pnm$(EXEEXT) png2pnm.o $(LIBS_SHARED) -lm
+
+pnm2png$(EXEEXT): pnm2png.o
+	$(LD) $(LDFLAGS) -o pnm2png$(EXEEXT) pnm2png.o $(LIBS_SHARED) -lm
+
+png2pnm-static$(EXEEXT): png2pnm.o
+	$(LD) $(LDFLAGS) -o png2pnm-static$(EXEEXT) png2pnm.o $(LIBS_STATIC) -lm
+
+pnm2png-static$(EXEEXT): pnm2png.o
+	$(LD) $(LDFLAGS) -o pnm2png-static$(EXEEXT) pnm2png.o $(LIBS_STATIC) -lm
+
+clean:
+	$(RM) png2pnm.o
+	$(RM) pnm2png.o
+	$(RM) png2pnm$(EXEEXT)
+	$(RM) pnm2png$(EXEEXT)
+	$(RM) png2pnm-static$(EXEEXT)
+	$(RM) pnm2png-static$(EXEEXT)
+
+# End of makefile for png2pnm / pnm2png

contrib/pngminus/README.txt

@@ -1,26 +1,16 @@
 PngMinus
 --------
-(copyright Willem van Schaik, 1999)
+(copyright Willem van Schaik, 1999-2019)
 
 
-License
--------
-
-Permission to use, copy, modify, and distribute this software and
-its documentation for any purpose and without fee is hereby granted,
-provided that the above copyright notice appear in all copies and
-that both that copyright notice and this permission notice appear in
-supporting documentation. This software is provided "as is" without
-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. 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/.
+and merged the two, which later became part of NetPBM, available from
+SourceForge.
 
 These two utilities have many, many options and make use of most of the
 features of PNG, like gamma, alpha, sbit, text-chunks, etc. This makes
@@ -35,8 +25,8 @@ makes the whole setup a bit bulky. But that's unavoidable given the many
 features of pnmtopng.
 
 
-What now
---------
+What now (1999)
+---------------
 At this moment libpng is in a very stable state and can do much of the
 work done in pnmtopng. Also, pnmtopng needs to be upgraded to the new
 interface of libpng. Hence, it is time for a rewrite from the ground up
@@ -49,8 +39,8 @@ a small prototype that contains only the basic functionality. It doesn't
 have any of the options to read or write special chunks and it will do
 no gamma correction. But this makes it also a simple program that is
 quite easy to understand and can serve well as a template for other
-software developments. (By now there are of course a couple of programs,
-like Greg Roelofs' rpng/wpng, that can be used just as good.)
+software developments. By now there are of course a couple of programs,
+like Greg Roelofs' rpng/wpng, that can be used just as good.
 
 
 Can and can not
@@ -60,7 +50,8 @@ PngMinus. Because I started this development in good-old Turbo-C, I
 avoided the use the netpbm library, which requires DOS extenders. Again,
 another reason to call it PngMinus (minus netpbm :-). So, part of the
 program are some elementary routines to read / write pgm- and ppm-files.
-It does not read b&w pbm-files.
+It does not handle B&W pbm-files, but instead you could do pgm with bit-
+depth 1.
 
 The downside of this approach is that you can not use them on images
 that require blocks of memory bigger than 64k (the DOS version). For
@@ -96,58 +87,34 @@ To list the options type "png2pnm -h" or "pnm2png -h".
 
 Just like Scandinavian furniture
 --------------------------------
-You have to put it together yourself. I did test the software under
-MS-DOS with Turbo-C 3.0 and under RedHat Linux 4.2 with gcc. In both
-cases I used libpng-1.0.4 and zlib-1.1.3. Later versions should be OK,
-however some older libpng versions have a bug in pngmem.c when using
-Turbo-C 3.0 (see below).
+You have to put it together yourself. I developed the software on MS-DOS
+with Turbo-C 3.0 and RedHat Linux 4.2 with gcc. In both cases I used
+libpng-1.0.4 and zlib-1.1.3. By now (2019) it is twenty years later and
+more current versions are OK.
 
-You can build it using one of the two makefiles (make -f makefile.###)
-or use the batch/script files pngminus.bat / pngminus.sh. This assumes
-that you have built the libraries in ../libpng and ../zlib. Using Linux,
-make sure that you have built libpng with makefile.std and not
-makefile.linux (also called .lnx in earlier versions of libpng). The
-latter creates a .so shared-library, while the PngMinus makefile assumes
-a normal .a static library.
+The makefile assumes that the libpng libraries can be found in ../.. and
+libz in ../../../zlib. But you can change this to for example ../libpng
+and ../zlib. The makefile creates two versions of each program, one with
+static library support and the other using shared libraries.
 
 If you create a ../pngsuite directory and then store the basn####.png
 files from PngSuite (http://www.schaik.com/pngsuite/) in there, you can
-test in one go the proper functioning of PngMinus, see png2pnm.bat and
-pnm2png.bat (or the .sh versions).
+test the proper functioning of PngMinus by running pngminus.sh.
 
 
 Warranty
 -------
 Please, remember that this was just a small experiment to learn a few
-things. It will have many unforeseen features <vbg>. Who said bugs? Use
-it when you are in need for something simple or when you want to start
-developing your own stuff.
-
-
-The Turbo bug
--------------
-** pngmem.old
-          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
-          hptr += 16L;
-** pngmem.c
-          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
-          hptr = hptr + 16L;
-**
-
-** pngmem.old
-          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
-          hptr += (png_uint_32)65536L;
-** pngmem.c
-          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
-          hptr = hptr + 65536L;
-**
+things. It will have many unforeseen features <vbg> ... who said bugs? Use
+it when you are in need for something simple or when you want a starting
+point for developing your own stuff.
 
 
 The end
 -------
 Willem van Schaik
-mailto:willem at schaik.com
+mailto:willem at schaik dot com
 http://www.schaik.com/png/
--------
-Oct 1999
+
+Oct 1999, Jan 2019
 

contrib/pngminus/makefile.std

@@ -1,66 +0,0 @@
-# Makefile for PngMinus (png2pnm and pnm2png)
-# Linux / Unix
-
-#CC=cc
-CC=gcc
-LD=$(CC)
-
-RM=rm -f
-
-#PNGPATH = /usr/local
-#PNGINC = -I$(PNGPATH)/include/libpng16
-#PNGLIB = -L$(PNGPATH)/lib -lpng16
-#PNGLIBS = $(PNGPATH)/lib/libpng16.a
-PNGINC = -I../..
-PNGLIB = -L../.. -lpng
-PNGLIBS = ../../libpng.a
-
-#ZPATH = /usr/local
-#ZINC = -I$(ZPATH)/include
-#ZLIB = -L$(ZPATH)/lib -lz
-#ZLIBS = $(ZPATH)/lib/libz.a
-ZINC = -I../../../zlib
-ZLIB = -L../../../zlib -lz
-ZLIBS = ../../../zlib/libz.a
-
-CPPFLAGS=$(PNGINC) $(ZINC)
-CFLAGS=
-LDLIBS=$(PNGLIB) $(ZLIB)
-LDLIBSS=$(PNGLIBS) $(ZLIBS)
-C=.c
-O=.o
-L=.a
-E=
-
-# dependencies
-
-#all: png2pnm$(E) pnm2png$(E)
-all: png2pnm$(E) pnm2png$(E) png2pnm-static$(E) pnm2png-static$(E)
-
-png2pnm$(O): png2pnm$(C)
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) png2pnm$(C)
-
-png2pnm$(E): png2pnm$(O)
-	$(LD) $(LDFLAGS) -o png2pnm$(E) png2pnm$(O) $(LDLIBS) -lm
-
-png2pnm-static$(E): png2pnm$(O)
-	$(LD) $(LDFLAGS) -o png2pnm-static$(E) png2pnm$(O) $(LDLIBSS) -lm
-
-pnm2png$(O): pnm2png$(C)
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) pnm2png$(C)
-
-pnm2png$(E): pnm2png$(O)
-	$(LD) $(LDFLAGS) -o pnm2png$(E) pnm2png$(O) $(LDLIBS) -lm
-
-pnm2png-static$(E): pnm2png$(O)
-	$(LD) $(LDFLAGS) -o pnm2png-static$(E) pnm2png$(O) $(LDLIBSS) -lm
-
-clean:
-	$(RM) png2pnm$(O)
-	$(RM) pnm2png$(O)
-	$(RM) png2pnm$(E)
-	$(RM) pnm2png$(E)
-	$(RM) png2pnm-static$(E)
-	$(RM) pnm2png-static$(E)
-
-# End of makefile for png2pnm / pnm2png

contrib/pngminus/makefile.tc3

@@ -1,38 +0,0 @@
-# Makefile for PngMinus (png2pnm and pnm2png)
-# TurboC++ 3.0
-
-CC=tcc -Ic:\tc3\inc
-LD=tcc -Lc:\tc3\lib
-LB=tlib
-RM=del
-CP=copy
-MODEL=l
-CPPFLAGS=-I..\libpng -I..\zlib
-CFLAGS=-O -m$(MODEL)
-LDFLAGS=-m$(MODEL) -L..\libpng -L..\zlib
-C=.c
-O=.obj
-L=.lib
-E=.exe
-
-# dependencies
-
-all: png2pnm$(E) pnm2png$(E)
-
-png2pnm$(O): png2pnm$(C)
-        $(CC) -c $(CPPFLAGS) $(CFLAGS) png2pnm$(C)
-
-png2pnm$(E): png2pnm$(O)
-        $(LD) $(LDFLAGS) png2pnm$(O) libpng$(L) zlib$(L)
-
-pnm2png$(O): pnm2png$(C)
-        $(CC) -c $(CPPFLAGS) $(CFLAGS) pnm2png$(C)
-
-pnm2png$(E): pnm2png$(O)
-        $(LD) $(LDFLAGS) pnm2png$(O) libpng$(L) zlib$(L)
-
-clean:
-        $(RM) *$(O)
-        $(RM) *$(E)
-
-# End of makefile for png2pnm / pnm2png

contrib/pngminus/png2pnm.c

@@ -1,85 +1,52 @@
 /*
  *  png2pnm.c --- conversion from PNG-file to PGM/PPM-file
- *  copyright (C) 1999,2017 by Willem van Schaik <willem at schaik.com>
+ *  copyright (C) 1999-2019 by Willem van Schaik <willem at schaik dot 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,
- *  provided that the above copyright notice appear in all copies and
- *  that both that copyright notice and this permission notice appear in
- *  supporting documentation. This software is provided "as is" without
- *  express or implied warranty.
+ *  This software is released under the MIT license. For conditions of
+ *  distribution and use, see the LICENSE file part of this package.
  */
 
 #include <stdio.h>
 #include <stdlib.h>
-#ifdef __TURBOC__
-#include <mem.h>
 #include <fcntl.h>
-#endif
-#include <zlib.h>
 
 #ifndef BOOL
 #define BOOL unsigned char
 #endif
 #ifndef TRUE
-#define TRUE (BOOL) 1
+#define TRUE ((BOOL) 1)
 #endif
 #ifndef FALSE
-#define FALSE (BOOL) 0
+#define FALSE ((BOOL) 0)
 #endif
 
-#ifdef __TURBOC__
-#define STDIN  0
-#define STDOUT 1
-#define STDERR 2
-#endif
-
-/* to make png2pnm verbose so we can find problems (needs to be before png.h) */
-#ifndef PNG_DEBUG
-#define PNG_DEBUG 0
-#endif
-
-
 #include "png.h"
 
-/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
-#ifndef png_jmpbuf
-#  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[]);
+int main (int argc, char *argv[]);
 void usage ();
-BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw,
-   BOOL alpha);
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
+              BOOL raw, BOOL alpha);
+BOOL do_png2pnm (png_struct *png_ptr, png_info *info_ptr,
+                 FILE *pnm_file, FILE *alpha_file,
+                 BOOL raw, BOOL alpha);
 
 /*
  *  main
  */
 
-int main(int argc, char *argv[])
+int main (int argc, char *argv[])
 {
   FILE *fp_rd = stdin;
   FILE *fp_wr = stdout;
   FILE *fp_al = NULL;
+  const char *fname_wr = NULL;
+  const char *fname_al = NULL;
   BOOL raw = TRUE;
   BOOL alpha = FALSE;
   int argi;
+  int ret;
 
   for (argi = 1; argi < argc; argi++)
   {
@@ -98,22 +65,23 @@ int main(int argc, char *argv[])
           argi++;
           if ((fp_al = fopen (argv[argi], "wb")) == NULL)
           {
+            fname_al = argv[argi];
             fprintf (stderr, "PNM2PNG\n");
-            fprintf (stderr, "Error:  can not create alpha-channel file %s\n",
-               argv[argi]);
+            fprintf (stderr, "Error:  cannot create alpha-channel file %s\n",
+                     argv[argi]);
             exit (1);
           }
           break;
         case 'h':
         case '?':
-          usage();
-          exit(0);
+          usage ();
+          exit (0);
           break;
         default:
           fprintf (stderr, "PNG2PNM\n");
           fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
-          usage();
-          exit(1);
+          usage ();
+          exit (1);
           break;
       } /* end switch */
     }
@@ -121,17 +89,18 @@ int main(int argc, char *argv[])
     {
       if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
       {
-             fprintf (stderr, "PNG2PNM\n");
-            fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
-            exit (1);
+        fprintf (stderr, "PNG2PNM\n");
+        fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
+        exit (1);
       }
     }
     else if (fp_wr == stdout)
     {
+      fname_wr = argv[argi];
       if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
       {
         fprintf (stderr, "PNG2PNM\n");
-        fprintf (stderr, "Error:  can not create file %s\n", argv[argi]);
+        fprintf (stderr, "Error:  cannot create file %s\n", argv[argi]);
         exit (1);
       }
     }
@@ -139,30 +108,21 @@ int main(int argc, char *argv[])
     {
       fprintf (stderr, "PNG2PNM\n");
       fprintf (stderr, "Error:  too many parameters\n");
-      usage();
-      exit(1);
+      usage ();
+      exit (1);
     }
   } /* end for */
 
-#ifdef __TURBOC__
+#if defined(O_BINARY) && (O_BINARY != 0)
   /* set stdin/stdout if required to binary */
   if (fp_rd == stdin)
-  {
-    setmode (STDIN, O_BINARY);
-  }
+    setmode (fileno (stdin), O_BINARY);
   if ((raw) && (fp_wr == stdout))
-  {
-    setmode (STDOUT, O_BINARY);
-  }
+    setmode (fileno (stdout), O_BINARY);
 #endif
 
   /* call the conversion program itself */
-  if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
-  {
-    fprintf (stderr, "PNG2PNM\n");
-    fprintf (stderr, "Error:  unsuccessful conversion of PNG-image\n");
-    exit(1);
-  }
+  ret = png2pnm (fp_rd, fp_wr, fp_al, raw, alpha);
 
   /* close input file */
   fclose (fp_rd);
@@ -172,6 +132,17 @@ int main(int argc, char *argv[])
   if (alpha)
     fclose (fp_al);
 
+  if (!ret)
+  {
+    fprintf (stderr, "PNG2PNM\n");
+    fprintf (stderr, "Error:  unsuccessful conversion of PNG-image\n");
+    if (fname_wr)
+      remove (fname_wr); /* no broken output file shall remain behind */
+    if (fname_al)
+      remove (fname_al); /* ditto */
+    exit (1);
+  }
+
   return 0;
 }
 
@@ -179,23 +150,18 @@ int main(int argc, char *argv[])
  *  usage
  */
 
-void usage()
+void usage ()
 {
   fprintf (stderr, "PNG2PNM\n");
   fprintf (stderr, "   by Willem van Schaik, 1999\n");
-#ifdef __TURBOC__
-  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
-#else
-  fprintf (stderr, "   for Linux (and Unix) compilers\n");
-#endif
   fprintf (stderr, "Usage:  png2pnm [options] <file>.png [<file>.pnm]\n");
   fprintf (stderr, "   or:  ... | png2pnm [options]\n");
   fprintf (stderr, "Options:\n");
   fprintf (stderr,
-     "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
+      "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
   fprintf (stderr, "   -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
   fprintf (stderr,
-     "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
+      "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
   fprintf (stderr, "   -h | -?  print this help-information\n");
 }
 
@@ -204,79 +170,70 @@ void usage()
  */
 
 BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
-    volatile BOOL raw, BOOL alpha)
+              BOOL raw, BOOL alpha)
 {
-  png_struct    *png_ptr = NULL;
-  png_info        *info_ptr = NULL;
-  png_byte      buf[8];
-  png_byte      *png_pixels = NULL;
-  png_byte      **row_pointers = NULL;
-  png_byte      *pix_ptr = NULL;
-  png_uint_32   row_bytes;
+  png_struct    *png_ptr;
+  png_info      *info_ptr;
+  BOOL          ret;
 
+  /* initialize the libpng context for reading from png_file */
+
+  png_ptr = png_create_read_struct (png_get_libpng_ver(NULL),
+                                    NULL, NULL, NULL);
+  if (!png_ptr)
+    return FALSE; /* out of memory */
+
+  info_ptr = png_create_info_struct (png_ptr);
+  if (!info_ptr)
+  {
+    png_destroy_read_struct (&png_ptr, NULL, NULL);
+    return FALSE; /* out of memory */
+  }
+
+  if (setjmp (png_jmpbuf (png_ptr)))
+  {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE; /* generic libpng error */
+  }
+
+  png_init_io (png_ptr, png_file);
+
+  /* do the actual conversion */
+  ret = do_png2pnm (png_ptr, info_ptr, pnm_file, alpha_file, raw, alpha);
+
+  /* clean up the libpng structures and their internally-managed data */
+  png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+
+  return ret;
+}
+
+/*
+ *  do_png2pnm - does the conversion in a fully-initialized libpng context
+ */
+
+BOOL do_png2pnm (png_struct *png_ptr, png_info *info_ptr,
+                 FILE *pnm_file, FILE *alpha_file,
+                 BOOL raw, BOOL alpha)
+{
+  png_byte      **row_pointers;
+  png_byte      *pix_ptr;
   png_uint_32   width;
   png_uint_32   height;
   int           bit_depth;
   int           channels;
   int           color_type;
   int           alpha_present;
-  int           row, col;
-  int           ret;
-  int           i;
+  png_uint_32   row, col, i;
   long          dep_16;
 
-  /* read and check signature in PNG file */
-  ret = fread (buf, 1, 8, png_file);
-  if (ret != 8)
-    return FALSE;
+  /* set up the image transformations that are necessary for the PNM format */
 
-  ret = png_sig_cmp (buf, 0, 8);
-  if (ret)
-    return FALSE;
+  /* set up (if applicable) the expansion of paletted images to full-color rgb,
+   * and the expansion of transparency maps to full alpha-channel */
+  png_set_expand (png_ptr);
 
-  /* create png and info structures */
-
-  png_ptr = png_create_read_struct (png_get_libpng_ver(NULL),
-    NULL, NULL, NULL);
-  if (!png_ptr)
-    return FALSE;   /* out of memory */
-
-  info_ptr = png_create_info_struct (png_ptr);
-  if (!info_ptr)
-  {
-    png_destroy_read_struct (&png_ptr, NULL, NULL);
-    return FALSE;   /* out of memory */
-  }
-
-  if (setjmp (png_jmpbuf(png_ptr)))
-  {
-    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
-    return FALSE;
-  }
-
-  /* set up the input control for C streams */
-  png_init_io (png_ptr, png_file);
-  png_set_sig_bytes (png_ptr, 8);  /* we already read the 8 signature bytes */
-
-  /* read the file information */
-  png_read_info (png_ptr, info_ptr);
-
-  /* get size and bit-depth of the PNG-image */
-  png_get_IHDR (png_ptr, info_ptr,
-    &width, &height, &bit_depth, &color_type,
-    NULL, NULL, NULL);
-
-  /* set-up the transformations */
-
-  /* transform paletted images into full-color rgb */
-  if (color_type == PNG_COLOR_TYPE_PALETTE)
-    png_set_expand (png_ptr);
-  /* expand images to bit-depth 8 (only applicable for grayscale images) */
-  if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
-    png_set_expand (png_ptr);
-  /* transform transparency maps into full alpha-channel */
-  if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
-    png_set_expand (png_ptr);
+  /* set up (if applicable) the expansion of grayscale images to bit-depth 8 */
+  png_set_expand_gray_1_2_4_to_8 (png_ptr);
 
 #ifdef NJET
   /* downgrade 16-bit images to 8-bit */
@@ -284,32 +241,24 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
     png_set_strip_16 (png_ptr);
   /* transform grayscale images into full-color */
   if (color_type == PNG_COLOR_TYPE_GRAY ||
-    color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
     png_set_gray_to_rgb (png_ptr);
-  /* only if file has a file gamma, we do a correction */
-  if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
-    png_set_gamma (png_ptr, (double) 2.2, file_gamma);
-#endif
-
-  /* all transformations have been registered; now update info_ptr data,
-   * get rowbytes and channels, and allocate image memory */
-
-  png_read_update_info (png_ptr, info_ptr);
-
-  /* get the new color-type and bit-depth (after expansion/stripping) */
-  png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
-    NULL, NULL, NULL);
-
-  /* check for 16-bit files */
-  if (bit_depth == 16)
+  /* if the PNG image has a gAMA chunk then gamma-correct the output image */
   {
-    raw = FALSE;
-#ifdef __TURBOC__
-    pnm_file->flags &= ~((unsigned) _F_BIN);
-#endif
+    double file_gamma;
+    if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
+      png_set_gamma (png_ptr, (double) 2.2, file_gamma);
   }
+#endif
 
-  /* calculate new number of channels and store alpha-presence */
+  /* read the image file, with all of the above image transforms applied */
+  png_read_png (png_ptr, info_ptr, 0, NULL);
+
+  /* get the image size, bit-depth and color-type */
+  png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+                NULL, NULL, NULL);
+
+  /* calculate the number of channels and store alpha-presence */
   if (color_type == PNG_COLOR_TYPE_GRAY)
     channels = 1;
   else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
@@ -326,47 +275,12 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
   if (alpha && !alpha_present)
   {
     fprintf (stderr, "PNG2PNM\n");
-    fprintf (stderr, "Error:  PNG-file doesn't contain alpha channel\n");
-    exit (1);
-  }
-
-  /* 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 ((size_t)row_bytes * (size_t)height * sizeof (png_byte))) == NULL)
-  {
-    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    fprintf (stderr, "Warning:  no alpha channel in PNG file\n");
     return FALSE;
   }
 
-  if ((row_pointers = (png_byte **)
-     malloc ((size_t)height * sizeof (png_bytep))) == NULL)
-  {
-    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
-    free (png_pixels);
-    png_pixels = NULL;
-    return FALSE;
-  }
-
-  /* set the individual row_pointers to point at the correct offsets */
-  for (i = 0; i < ((int) height); i++)
-    row_pointers[i] = png_pixels + i * row_bytes;
-
-  /* now we can go ahead and just read the whole image */
-  png_read_image (png_ptr, row_pointers);
-
-  /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
-  png_read_end (png_ptr, info_ptr);
-
-  /* clean up after the read, and free any memory allocated - REQUIRED */
-  png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL);
+  /* get address of internally-allocated image data */
+  row_pointers = png_get_rows (png_ptr, info_ptr);
 
   /* write header of PNM file */
 
@@ -397,46 +311,67 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
   }
 
   /* write data to PNM file */
-  pix_ptr = png_pixels;
 
-  for (row = 0; row < (int) height; row++)
+  for (row = 0; row < height; row++)
   {
-    for (col = 0; col < (int) width; col++)
+    pix_ptr = row_pointers[row];
+    for (col = 0; col < width; col++)
     {
-      for (i = 0; i < (channels - alpha_present); i++)
+      for (i = 0; i < (png_uint_32) (channels - alpha_present); i++)
       {
         if (raw)
-          fputc ((int) *pix_ptr++ , pnm_file);
+        {
+          fputc ((int) *pix_ptr++, pnm_file);
+          if (bit_depth == 16)
+            fputc ((int) *pix_ptr++, pnm_file);
+        }
         else
-          if (bit_depth == 16){
-            dep_16 = (long) *pix_ptr++;
-            fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++));
+        {
+          if (bit_depth == 16)
+          {
+            dep_16 = ((long) *pix_ptr++) << 8;
+            dep_16 += ((long) *pix_ptr++);
+            fprintf (pnm_file, "%ld ", dep_16);
           }
           else
+          {
             fprintf (pnm_file, "%ld ", (long) *pix_ptr++);
+          }
+        }
       }
       if (alpha_present)
       {
         if (!alpha)
         {
-          pix_ptr++; /* alpha */
+          /* skip the alpha-channel */
+          pix_ptr++;
           if (bit_depth == 16)
             pix_ptr++;
         }
-        else /* output alpha-channel as pgm file */
+        else
         {
+          /* output the alpha-channel as pgm file */
           if (raw)
-            fputc ((int) *pix_ptr++ , alpha_file);
+          {
+            fputc ((int) *pix_ptr++, alpha_file);
+            if (bit_depth == 16)
+              fputc ((int) *pix_ptr++, alpha_file);
+          }
           else
+          {
             if (bit_depth == 16)
             {
-              dep_16 = (long) *pix_ptr++;
-              fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
+              dep_16 = ((long) *pix_ptr++) << 8;
+              dep_16 += ((long) *pix_ptr++);
+              fprintf (alpha_file, "%ld ", dep_16);
             }
             else
+            {
               fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
+            }
+          }
         }
-      } /* if alpha_present */
+      } /* end if alpha_present */
 
       if (!raw)
         if (col % 4 == 3)
@@ -448,13 +383,5 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
         fprintf (pnm_file, "\n");
   } /* end for row */
 
-  if (row_pointers != (unsigned char**) NULL)
-    free (row_pointers);
-  if (png_pixels != (unsigned char*) NULL)
-    free (png_pixels);
-
-  PNGMINUS_UNUSED(raw); /* to quiet a Coverity defect */
   return TRUE;
-
 } /* end of source */
-

contrib/pngminus/pnm2png.c

@@ -1,87 +1,57 @@
 /*
  *  pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file
- *  copyright (C) 1999,2015,2017 by Willem van Schaik <willem at schaik.com>
+ *  copyright (C) 1999-2019 by Willem van Schaik <willem at schaik dot 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,
- *  provided that the above copyright notice appear in all copies and
- *  that both that copyright notice and this permission notice appear in
- *  supporting documentation. This software is provided "as is" without
- *  express or implied warranty.
+ *  This software is released under the MIT license. For conditions of
+ *  distribution and use, see the LICENSE file part of this package.
  */
 
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
-#ifdef __TURBOC__
-#include <mem.h>
 #include <fcntl.h>
-#endif
-#include <zlib.h>
 
 #ifndef BOOL
 #define BOOL unsigned char
 #endif
 #ifndef TRUE
-#define TRUE (BOOL) 1
+#define TRUE ((BOOL) 1)
 #endif
 #ifndef FALSE
-#define FALSE (BOOL) 0
-#endif
-
-#define STDIN  0
-#define STDOUT 1
-#define STDERR 2
-
-/* to make pnm2png verbose so we can find problems (needs to be before png.h) */
-#ifndef PNG_DEBUG
-#define PNG_DEBUG 0
+#define FALSE ((BOOL) 0)
 #endif
 
 #include "png.h"
 
-/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
-#ifndef png_jmpbuf
-#  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[]);
+int main (int argc, char *argv[]);
 void usage ();
-BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
-    BOOL alpha);
-void get_token(FILE *pnm_file, char *token);
-png_uint_32 get_data (FILE *pnm_file, int depth);
-png_uint_32 get_value (FILE *pnm_file, int depth);
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file,
+              BOOL interlace, BOOL alpha);
+BOOL do_pnm2png (png_struct *png_ptr, png_info *info_ptr,
+                 FILE *pnm_file, FILE *alpha_file,
+                 BOOL interlace, BOOL alpha);
+int fscan_pnm_magic (FILE *pnm_file, char *magic_buf, size_t magic_buf_size);
+int fscan_pnm_token (FILE *pnm_file, char *token_buf, size_t token_buf_size);
+int fscan_pnm_uint_32 (FILE *pnm_file, png_uint_32 *num_ptr);
+png_uint_32 get_pnm_data (FILE *pnm_file, int depth);
+png_uint_32 get_pnm_value (FILE *pnm_file, int depth);
 
 /*
  *  main
  */
 
-int main(int argc, char *argv[])
+int main (int argc, char *argv[])
 {
   FILE *fp_rd = stdin;
   FILE *fp_al = NULL;
   FILE *fp_wr = stdout;
+  const char *fname_wr = NULL;
   BOOL interlace = FALSE;
   BOOL alpha = FALSE;
   int argi;
+  int ret;
 
   for (argi = 1; argi < argc; argi++)
   {
@@ -99,20 +69,20 @@ int main(int argc, char *argv[])
           {
             fprintf (stderr, "PNM2PNG\n");
             fprintf (stderr, "Error:  alpha-channel file %s does not exist\n",
-               argv[argi]);
+                     argv[argi]);
             exit (1);
           }
           break;
         case 'h':
         case '?':
-          usage();
-          exit(0);
+          usage ();
+          exit (0);
           break;
         default:
           fprintf (stderr, "PNM2PNG\n");
           fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
-          usage();
-          exit(1);
+          usage ();
+          exit (1);
           break;
       } /* end switch */
     }
@@ -127,10 +97,11 @@ int main(int argc, char *argv[])
     }
     else if (fp_wr == stdout)
     {
+      fname_wr = argv[argi];
       if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
       {
         fprintf (stderr, "PNM2PNG\n");
-        fprintf (stderr, "Error:  can not create PNG-file %s\n", argv[argi]);
+        fprintf (stderr, "Error:  cannot create PNG-file %s\n", argv[argi]);
         exit (1);
       }
     }
@@ -138,30 +109,23 @@ int main(int argc, char *argv[])
     {
       fprintf (stderr, "PNM2PNG\n");
       fprintf (stderr, "Error:  too many parameters\n");
-      usage();
+      usage ();
       exit (1);
     }
   } /* end for */
 
-#ifdef __TURBOC__
-  /* set stdin/stdout to binary, we're reading the PNM always! in binary format */
+#if defined(O_BINARY) && (O_BINARY != 0)
+  /* set stdin/stdout to binary,
+   * we're reading the PNM always! in binary format
+   */
   if (fp_rd == stdin)
-  {
-    setmode (STDIN, O_BINARY);
-  }
+    setmode (fileno (stdin), O_BINARY);
   if (fp_wr == stdout)
-  {
-    setmode (STDOUT, O_BINARY);
-  }
+    setmode (fileno (stdout), O_BINARY);
 #endif
 
   /* call the conversion program itself */
-  if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
-  {
-    fprintf (stderr, "PNM2PNG\n");
-    fprintf (stderr, "Error:  unsuccessful converting to PNG-image\n");
-    exit (1);
-  }
+  ret = pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha);
 
   /* close input file */
   fclose (fp_rd);
@@ -171,6 +135,15 @@ int main(int argc, char *argv[])
   if (alpha)
     fclose (fp_al);
 
+  if (!ret)
+  {
+    fprintf (stderr, "PNM2PNG\n");
+    fprintf (stderr, "Error:  unsuccessful converting to PNG-image\n");
+    if (fname_wr)
+      remove (fname_wr); /* no broken output file shall remain behind */
+    exit (1);
+  }
+
   return 0;
 }
 
@@ -178,15 +151,10 @@ int main(int argc, char *argv[])
  *  usage
  */
 
-void usage()
+void usage ()
 {
   fprintf (stderr, "PNM2PNG\n");
   fprintf (stderr, "   by Willem van Schaik, 1999\n");
-#ifdef __TURBOC__
-  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
-#else
-  fprintf (stderr, "   for Linux (and Unix) compilers\n");
-#endif
   fprintf (stderr, "Usage:  pnm2png [options] <file>.<pnm> [<file>.png]\n");
   fprintf (stderr, "   or:  ... | pnm2png [options]\n");
   fprintf (stderr, "Options:\n");
@@ -200,103 +168,101 @@ void usage()
  *  pnm2png
  */
 
-BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
-     BOOL alpha)
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file,
+              BOOL interlace, BOOL alpha)
 {
-  png_struct    *png_ptr = NULL;
-  png_info      *info_ptr = NULL;
-  png_byte      *png_pixels = NULL;
-  png_byte      **row_pointers = NULL;
-  png_byte      *pix_ptr = NULL;
-  volatile png_uint_32   row_bytes;
+  png_struct    *png_ptr;
+  png_info      *info_ptr;
+  BOOL          ret;
 
-  char          type_token[16];
-  char          width_token[16];
-  char          height_token[16];
-  char          maxval_token[16];
-  volatile int    color_type=1;
-  unsigned long   ul_width=0, ul_alpha_width=0;
-  unsigned long   ul_height=0, ul_alpha_height=0;
-  unsigned long   ul_maxval=0;
-  volatile png_uint_32   width=0, height=0;
-  volatile png_uint_32   alpha_width=0, alpha_height=0;
-  png_uint_32   maxval;
-  volatile int           bit_depth = 0;
-  int           channels=0;
-  int           alpha_depth = 0;
-  int           alpha_present=0;
-  int           row, col;
-  BOOL          raw, alpha_raw = FALSE;
-#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  /* initialize the libpng context for writing to png_file */
+
+  png_ptr = png_create_write_struct (png_get_libpng_ver(NULL),
+                                     NULL, NULL, NULL);
+  if (!png_ptr)
+    return FALSE; /* out of memory */
+
+  info_ptr = png_create_info_struct (png_ptr);
+  if (!info_ptr)
+  {
+    png_destroy_write_struct (&png_ptr, NULL);
+    return FALSE; /* out of memory */
+  }
+
+  if (setjmp (png_jmpbuf (png_ptr)))
+  {
+    png_destroy_write_struct (&png_ptr, &info_ptr);
+    return FALSE; /* generic libpng error */
+  }
+
+  png_init_io (png_ptr, png_file);
+
+  /* do the actual conversion */
+  ret = do_pnm2png (png_ptr, info_ptr, pnm_file, alpha_file, interlace, alpha);
+
+  /* clean up the libpng structures and their internally-managed data */
+  png_destroy_write_struct (&png_ptr, &info_ptr);
+
+  return ret;
+}
+
+/*
+ *  do_pnm2png - does the conversion in a fully-initialized libpng context
+ */
+
+BOOL do_pnm2png (png_struct *png_ptr, png_info *info_ptr,
+                 FILE *pnm_file, FILE *alpha_file,
+                 BOOL interlace, BOOL alpha)
+{
+  png_byte      **row_pointers;
+  png_byte      *pix_ptr;
+  int           bit_depth;
+  int           color_type;
+  int           channels;
+  char          magic_token[4];
+  BOOL          raw;
+  png_uint_32   width, height, maxval;
+  png_uint_32   row_bytes;
+  png_uint_32   row, col;
+  png_uint_32   val16, i;
+  png_uint_32   alpha_width = 0, alpha_height = 0;
+  int           alpha_depth = 0, alpha_present = 0;
+  BOOL          alpha_raw = FALSE;
   BOOL          packed_bitmap = FALSE;
-#endif
-  png_uint_32   tmp16;
-  int           i;
 
   /* read header of PNM file */
 
-  get_token(pnm_file, type_token);
-  if (type_token[0] != 'P')
-  {
-    return FALSE;
-  }
-  else if ((type_token[1] == '1') || (type_token[1] == '4'))
-  {
-#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
-    raw = (type_token[1] == '4');
-    color_type = PNG_COLOR_TYPE_GRAY;
-    get_token(pnm_file, width_token);
-    sscanf (width_token, "%lu", &ul_width);
-    width = (png_uint_32) ul_width;
-    get_token(pnm_file, height_token);
-    sscanf (height_token, "%lu", &ul_height);
-    height = (png_uint_32) ul_height;
-    bit_depth = 1;
-    packed_bitmap = TRUE;
-#else
-    fprintf (stderr, "PNM2PNG built without PNG_WRITE_INVERT_SUPPORTED and \n");
-    fprintf (stderr, "PNG_WRITE_PACK_SUPPORTED can't read PBM (P1,P4) files\n");
-#endif
-  }
-  else if ((type_token[1] == '2') || (type_token[1] == '5'))
-  {
-    raw = (type_token[1] == '5');
-    color_type = PNG_COLOR_TYPE_GRAY;
-    get_token(pnm_file, width_token);
-    sscanf (width_token, "%lu", &ul_width);
-    width = (png_uint_32) ul_width;
-    get_token(pnm_file, height_token);
-    sscanf (height_token, "%lu", &ul_height);
-    height = (png_uint_32) ul_height;
-    get_token(pnm_file, maxval_token);
-    sscanf (maxval_token, "%lu", &ul_maxval);
-    maxval = (png_uint_32) ul_maxval;
+  if (fscan_pnm_magic (pnm_file, magic_token, sizeof (magic_token)) != 1)
+    return FALSE; /* not a PNM file */
 
-    if (maxval <= 1)
-      bit_depth = 1;
-    else if (maxval <= 3)
-      bit_depth = 2;
-    else if (maxval <= 15)
-      bit_depth = 4;
-    else if (maxval <= 255)
-      bit_depth = 8;
-    else /* if (maxval <= 65535) */
-      bit_depth = 16;
-  }
-  else if ((type_token[1] == '3') || (type_token[1] == '6'))
+  if ((magic_token[1] == '1') || (magic_token[1] == '4'))
   {
-    raw = (type_token[1] == '6');
-    color_type = PNG_COLOR_TYPE_RGB;
-    get_token(pnm_file, width_token);
-    sscanf (width_token, "%lu", &ul_width);
-    width = (png_uint_32) ul_width;
-    get_token(pnm_file, height_token);
-    sscanf (height_token, "%lu", &ul_height);
-    height = (png_uint_32) ul_height;
-    get_token(pnm_file, maxval_token);
-    sscanf (maxval_token, "%lu", &ul_maxval);
-    maxval = (png_uint_32) ul_maxval;
-    if (maxval <= 1)
+    if ((fscan_pnm_uint_32 (pnm_file, &width) != 1) ||
+        (fscan_pnm_uint_32 (pnm_file, &height) != 1))
+      return FALSE; /* bad PBM file header */
+  } else if ((magic_token[1] == '2') || (magic_token[1] == '5') ||
+             (magic_token[1] == '3') || (magic_token[1] == '6'))
+  {
+    if ((fscan_pnm_uint_32 (pnm_file, &width) != 1) ||
+        (fscan_pnm_uint_32 (pnm_file, &height) != 1) ||
+        (fscan_pnm_uint_32 (pnm_file, &maxval) != 1))
+      return FALSE; /* bad PGM/PPM file header */
+  }
+
+  if ((magic_token[1] == '1') || (magic_token[1] == '4'))
+  {
+    raw = (magic_token[1] == '4');
+    bit_depth = 1;
+    color_type = PNG_COLOR_TYPE_GRAY;
+    packed_bitmap = TRUE;
+  }
+  else if ((magic_token[1] == '2') || (magic_token[1] == '5'))
+  {
+    raw = (magic_token[1] == '5');
+    color_type = PNG_COLOR_TYPE_GRAY;
+    if (maxval == 0)
+      return FALSE;
+    else if (maxval == 1)
       bit_depth = 1;
     else if (maxval <= 3)
       bit_depth = 2;
@@ -304,8 +270,34 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
       bit_depth = 4;
     else if (maxval <= 255)
       bit_depth = 8;
-    else /* if (maxval <= 65535) */
+    else if (maxval <= 65535U)
       bit_depth = 16;
+    else /* maxval > 65535U */
+      return FALSE;
+  }
+  else if ((magic_token[1] == '3') || (magic_token[1] == '6'))
+  {
+    raw = (magic_token[1] == '6');
+    color_type = PNG_COLOR_TYPE_RGB;
+    if (maxval == 0)
+      return FALSE;
+    else if (maxval == 1)
+      bit_depth = 1;
+    else if (maxval <= 3)
+      bit_depth = 2;
+    else if (maxval <= 15)
+      bit_depth = 4;
+    else if (maxval <= 255)
+      bit_depth = 8;
+    else if (maxval <= 65535U)
+      bit_depth = 16;
+    else /* maxval > 65535U */
+      return FALSE;
+  }
+  else if (magic_token[1] == '7')
+  {
+    fprintf (stderr, "PNM2PNG can't read PAM (P7) files\n");
+    return FALSE;
   }
   else
   {
@@ -316,49 +308,36 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
 
   if (alpha)
   {
-    if (color_type == PNG_COLOR_TYPE_GRAY)
-      color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
-    if (color_type == PNG_COLOR_TYPE_RGB)
-      color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+    if ((fscan_pnm_magic (alpha_file, magic_token, sizeof (magic_token)) != 1)
+        || ((magic_token[1] != '2') && (magic_token[1] != '5')))
+      return FALSE; /* not a PGM file */
 
-    get_token(alpha_file, type_token);
-    if (type_token[0] != 'P')
-    {
+    if ((fscan_pnm_uint_32 (alpha_file, &alpha_width) != 1) ||
+        (fscan_pnm_uint_32 (alpha_file, &alpha_height) != 1) ||
+        (fscan_pnm_uint_32 (alpha_file, &maxval) != 1))
+      return FALSE; /* bad PGM file header */
+
+    if ((alpha_width != width) || (alpha_height != height))
+      return FALSE; /* mismatched PGM dimensions */
+
+    alpha_raw = (magic_token[1] == '5');
+    color_type |= PNG_COLOR_MASK_ALPHA;
+    if (maxval == 0)
       return FALSE;
-    }
-    else if ((type_token[1] == '2') || (type_token[1] == '5'))
-    {
-      alpha_raw = (type_token[1] == '5');
-      get_token(alpha_file, width_token);
-      sscanf (width_token, "%lu", &ul_alpha_width);
-      alpha_width=(png_uint_32) ul_alpha_width;
-      if (alpha_width != width)
-        return FALSE;
-      get_token(alpha_file, height_token);
-      sscanf (height_token, "%lu", &ul_alpha_height);
-      alpha_height = (png_uint_32) ul_alpha_height;
-      if (alpha_height != height)
-        return FALSE;
-      get_token(alpha_file, maxval_token);
-      sscanf (maxval_token, "%lu", &ul_maxval);
-      maxval = (png_uint_32) ul_maxval;
-      if (maxval <= 1)
-        alpha_depth = 1;
-      else if (maxval <= 3)
-        alpha_depth = 2;
-      else if (maxval <= 15)
-        alpha_depth = 4;
-      else if (maxval <= 255)
-        alpha_depth = 8;
-      else /* if (maxval <= 65535) */
-        alpha_depth = 16;
-      if (alpha_depth != bit_depth)
-        return FALSE;
-    }
-    else
-    {
+    else if (maxval == 1)
+      alpha_depth = 1;
+    else if (maxval <= 3)
+      alpha_depth = 2;
+    else if (maxval <= 15)
+      alpha_depth = 4;
+    else if (maxval <= 255)
+      alpha_depth = 8;
+    else if (maxval <= 65535U)
+      alpha_depth = 16;
+    else /* maxval > 65535U */
+      return FALSE;
+    if (alpha_depth != bit_depth)
       return FALSE;
-    }
   } /* end if alpha */
 
   /* calculate the number of channels and store alpha-presence */
@@ -370,219 +349,259 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
     channels = 3;
   else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
     channels = 4;
-#if 0
   else
-    channels = 0; /* cannot happen */
-#endif
+    return FALSE; /* NOTREACHED */
 
   alpha_present = (channels - 1) % 2;
 
-#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
   if (packed_bitmap)
+  {
     /* row data is as many bytes as can fit width x channels x bit_depth */
     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 = width * channels * ((bit_depth <= 8) ? 1 : 2);
-
-  if ((row_bytes == 0 || (size_t)height > ((size_t)(-1))/(size_t)row_bytes))
   {
-    /* too big */ 
+    /* 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 ((size_t)row_bytes * (size_t)height * sizeof (png_byte))) == NULL)
-    return FALSE;
 
-  /* read data from PNM file */
-  pix_ptr = png_pixels;
-
-  for (row = 0; row < (int) height; row++)
+  /* allocate the rows using the same memory layout as libpng, and transfer
+   * their ownership to libpng, with the responsibility to clean everything up;
+   * please note the use of png_calloc instead of png_malloc */
+  row_pointers = (png_byte **)
+                 png_calloc (png_ptr, height * sizeof (png_byte *));
+  png_set_rows (png_ptr, info_ptr, row_pointers);
+  png_data_freer (png_ptr, info_ptr, PNG_DESTROY_WILL_FREE_DATA, PNG_FREE_ALL);
+  for (row = 0; row < height; row++)
   {
-#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+    /* the individual rows should only be allocated after all the previous
+     * steps completed successfully, because libpng must handle correctly
+     * any image allocation left incomplete after an out-of-memory error */
+    row_pointers[row] = (png_byte *) png_malloc (png_ptr, row_bytes);
+  }
+
+  /* read the data from PNM file */
+
+  for (row = 0; row < height; row++)
+  {
+    pix_ptr = row_pointers[row];
     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);
-    } else
-#endif
-    {
-      for (col = 0; col < (int) width; col++)
+      for (i = 0; i < row_bytes; i++)
       {
-        for (i = 0; i < (channels - alpha_present); i++)
+        /* png supports this format natively so no conversion is needed */
+        *pix_ptr++ = get_pnm_data (pnm_file, 8);
+      }
+    }
+    else
+    {
+      for (col = 0; col < width; col++)
+      {
+        for (i = 0; i < (png_uint_32) (channels - alpha_present); i++)
         {
           if (raw)
-            *pix_ptr++ = get_data (pnm_file, bit_depth);
+          {
+            *pix_ptr++ = get_pnm_data (pnm_file, bit_depth);
+            if (bit_depth == 16)
+              *pix_ptr++ = get_pnm_data (pnm_file, bit_depth);
+          }
           else
+          {
             if (bit_depth <= 8)
-              *pix_ptr++ = get_value (pnm_file, bit_depth);
+            {
+              *pix_ptr++ = get_pnm_value (pnm_file, bit_depth);
+            }
             else
             {
-              tmp16 = get_value (pnm_file, bit_depth);
-              *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
+              val16 = get_pnm_value (pnm_file, bit_depth);
+              *pix_ptr = (png_byte) ((val16 >> 8) & 0xFF);
               pix_ptr++;
-              *pix_ptr = (png_byte) (tmp16 & 0xFF);
+              *pix_ptr = (png_byte) (val16 & 0xFF);
               pix_ptr++;
             }
+          }
         }
 
         if (alpha) /* read alpha-channel from pgm file */
         {
           if (alpha_raw)
-            *pix_ptr++ = get_data (alpha_file, alpha_depth);
+          {
+            *pix_ptr++ = get_pnm_data (alpha_file, alpha_depth);
+            if (alpha_depth == 16)
+              *pix_ptr++ = get_pnm_data (alpha_file, alpha_depth);
+          }
           else
+          {
             if (alpha_depth <= 8)
-              *pix_ptr++ = get_value (alpha_file, bit_depth);
+            {
+              *pix_ptr++ = get_pnm_value (alpha_file, bit_depth);
+            }
             else
             {
-              tmp16 = get_value (alpha_file, bit_depth);
-              *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
-              *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
+              val16 = get_pnm_value (alpha_file, bit_depth);
+              *pix_ptr++ = (png_byte) ((val16 >> 8) & 0xFF);
+              *pix_ptr++ = (png_byte) (val16 & 0xFF);
             }
-        } /* if alpha */
-      } /* if packed_bitmap */
+          }
+        } /* end if alpha */
+      } /* end if packed_bitmap */
     } /* end for col */
   } /* end for row */
 
-  /* prepare the standard PNG structures */
-  png_ptr = png_create_write_struct (png_get_libpng_ver(NULL), NULL, NULL,
-      NULL);
-  if (!png_ptr)
-  {
-    free (png_pixels);
-    png_pixels = NULL;
-    return FALSE;
-  }
-  info_ptr = png_create_info_struct (png_ptr);
-  if (!info_ptr)
-  {
-    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
-    free (png_pixels);
-    png_pixels = NULL;
-    return FALSE;
-  }
+  /* we're going to write more or less the same PNG as the input file */
+  png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
+                (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
+                PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
-#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
   if (packed_bitmap == TRUE)
   {
     png_set_packing (png_ptr);
     png_set_invert_mono (png_ptr);
   }
-#endif
-
-  /* setjmp() must be called in every function that calls a PNG-reading libpng function */
-  if (setjmp (png_jmpbuf(png_ptr)))
-  {
-    png_destroy_write_struct (&png_ptr, &info_ptr);
-    free (png_pixels);
-    png_pixels = NULL;
-    return FALSE;
-  }
-
-  /* initialize the png structure */
-  png_init_io (png_ptr, png_file);
-
-  /* we're going to write more or less the same PNG as the input file */
-  png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
-    (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
-    PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
   /* write the file header information */
   png_write_info (png_ptr, info_ptr);
 
-  /* if needed we will allocate memory for an new array of row-pointers */
-  if (row_pointers == (unsigned char**) NULL)
-  {
-    if ((row_pointers = (png_byte **)
-        malloc (height * sizeof (png_bytep))) == NULL)
-    {
-      png_destroy_write_struct (&png_ptr, &info_ptr);
-      free (png_pixels);
-      png_pixels = NULL;
-      return FALSE;
-    }
-  }
-
-  /* set the individual row_pointers to point at the correct offsets */
-  for (i = 0; i < (int) height; i++)
-    row_pointers[i] = png_pixels + i * row_bytes;
-
   /* write out the entire image data in one call */
   png_write_image (png_ptr, row_pointers);
 
   /* write the additional chunks to the PNG file (not really needed) */
   png_write_end (png_ptr, info_ptr);
 
-  /* clean up after the write, and free any memory allocated */
-  png_destroy_write_struct (&png_ptr, &info_ptr);
-
-  if (row_pointers != (unsigned char**) NULL)
-    free (row_pointers);
-  if (png_pixels != (unsigned char*) NULL)
-    free (png_pixels);
-
-  PNGMINUS_UNUSED(raw); /* Quiet a Coverity defect */
-
   return TRUE;
 } /* end of pnm2png */
 
 /*
- * get_token() - gets the first string after whitespace
+ * fscan_pnm_magic - like fscan_pnm_token below, but expects the magic string
+ *                   to start immediately, without any comment or whitespace,
+ *                   and to match the regex /^P[1-9]$/
  */
 
-void get_token(FILE *pnm_file, char *token)
+int fscan_pnm_magic (FILE *pnm_file, char *magic_buf, size_t magic_buf_size)
 {
-  int i = 0;
+  int ret;
+
+  ret = fgetc (pnm_file);
+  if (ret == EOF) return 0;
+  ungetc (ret, pnm_file);
+  if (ret != 'P') return 0;
+
+  /* the string buffer must be at least four bytes long, i.e., the capacity
+   * required for strings of at least three characters long, i.e., the minimum
+   * required for ensuring that our magic string is exactly two characters long
+   */
+  if (magic_buf_size < 4) return -1;
+
+  ret = fscan_pnm_token (pnm_file, magic_buf, magic_buf_size);
+  if (ret < 1) return ret;
+
+  if ((magic_buf[1] < '1') || (magic_buf[1] > '9')) return 0;
+  if (magic_buf[2] != '\0') return 0;
+
+  return 1;
+}
+
+/*
+ * fscan_pnm_token - extracts the first string token after whitespace,
+ *                   and (like fscanf) returns the number of successful
+ *                   extractions, which can be either 0 or 1
+ */
+
+int fscan_pnm_token (FILE *pnm_file, char *token_buf, size_t token_buf_size)
+{
+  size_t i = 0;
   int ret;
 
   /* remove white-space and comment lines */
   do
   {
-    ret = fgetc(pnm_file);
+    ret = fgetc (pnm_file);
     if (ret == '#')
     {
       /* the rest of this line is a comment */
       do
       {
-        ret = fgetc(pnm_file);
+        ret = fgetc (pnm_file);
       }
       while ((ret != '\n') && (ret != '\r') && (ret != EOF));
     }
     if (ret == EOF) break;
-    token[i] = (unsigned char) ret;
+    token_buf[i] = (char) ret;
   }
-  while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
+  while ((ret == '\n') || (ret == '\r') || (ret == ' '));
 
   /* read string */
   do
   {
-    ret = fgetc(pnm_file);
+    ret = fgetc (pnm_file);
     if (ret == EOF) break;
-    i++;
-    token[i] = (unsigned char) ret;
+    if (ret == '0')
+    {
+      /* avoid storing more than one leading '0' in the token buffer,
+       * to ensure that all valid (in-range) numeric inputs can fit in. */
+      if ((i == 0) && (token_buf[i] == '0')) continue;
+    }
+    if (++i == token_buf_size - 1) break;
+    token_buf[i] = (char) ret;
   }
-  while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
+  while ((ret != '\n') && (ret != '\r') && (ret != ' '));
 
-  token[i] = '\0';
-
-  return;
+  token_buf[i] = '\0';
+  return (i > 0) ? 1 : 0;
 }
 
 /*
- * get_data() - takes first byte and converts into next pixel value,
- *        taking as much bits as defined by bit-depth and
- *        using the bit-depth to fill up a byte (0Ah -> AAh)
+ * fscan_pnm_uint_32 - like fscan_token above, but expects the extracted token
+ *                     to be numeric, and converts it to an unsigned 32-bit int
  */
 
-png_uint_32 get_data (FILE *pnm_file, int depth)
+int fscan_pnm_uint_32 (FILE *pnm_file, png_uint_32 *num_ptr)
+{
+  char token[16];
+  unsigned long token_value;
+  int ret;
+
+  ret = fscan_pnm_token (pnm_file, token, sizeof (token));
+  if (ret < 1) return ret;
+
+  if ((token[0] < '0') && (token[0] > '9'))
+    return 0; /* the token starts with junk, or a +/- sign, which is invalid */
+
+  ret = sscanf (token, "%lu%*c", &token_value);
+  if (ret != 1)
+    return 0; /* the token ends with junk */
+
+  *num_ptr = (png_uint_32) token_value;
+
+#if ULONG_MAX > 0xFFFFFFFFUL
+  /* saturate the converted number, following the fscanf convention */
+  if (token_value > 0xFFFFFFFFUL)
+    *num_ptr = 0xFFFFFFFFUL;
+#endif
+
+  return 1;
+}
+
+/*
+ *  get_pnm_data - takes first byte and converts into next pixel value,
+ *                 taking as many bits as defined by bit-depth and
+ *                 using the bit-depth to fill up a byte (0x0A -> 0xAA)
+ */
+
+png_uint_32 get_pnm_data (FILE *pnm_file, int depth)
 {
   static int bits_left = 0;
   static int old_value = 0;
   static int mask = 0;
-  int i;
   png_uint_32 ret_value;
+  int i;
 
   if (mask == 0)
     for (i = 0; i < depth; i++)
@@ -590,7 +609,11 @@ png_uint_32 get_data (FILE *pnm_file, int depth)
 
   if (bits_left <= 0)
   {
+    /* FIXME:
+     * signal the premature end of file, instead of pretending to read zeroes
+     */
     old_value = fgetc (pnm_file);
+    if (old_value == EOF) return 0;
     bits_left = 8;
   }
 
@@ -605,25 +628,28 @@ png_uint_32 get_data (FILE *pnm_file, int depth)
 }
 
 /*
- * get_value() - takes first (numeric) string and converts into number,
- *         using the bit-depth to fill up a byte (0Ah -> AAh)
+ *  get_pnm_value - takes first (numeric) string and converts into number,
+ *                  using the bit-depth to fill up a byte (0x0A -> 0xAA)
  */
 
-png_uint_32 get_value (FILE *pnm_file, int depth)
+png_uint_32 get_pnm_value (FILE *pnm_file, int depth)
 {
   static png_uint_32 mask = 0;
-  png_byte token[16];
-  unsigned long ul_ret_value;
   png_uint_32 ret_value;
-  int i = 0;
+  int i;
 
   if (mask == 0)
     for (i = 0; i < depth; i++)
       mask = (mask << 1) | 0x01;
 
-  get_token (pnm_file, (char *) token);
-  sscanf ((const char *) token, "%lu", &ul_ret_value);
-  ret_value = (png_uint_32) ul_ret_value;
+  if (fscan_pnm_uint_32 (pnm_file, &ret_value) != 1)
+  {
+    /* FIXME:
+     * signal the invalid numeric tokens or the premature end of file,
+     * instead of pretending to read zeroes
+     */
+    return 0;
+  }
 
   ret_value &= mask;
 
@@ -635,4 +661,3 @@ png_uint_32 get_value (FILE *pnm_file, int depth)
 }
 
 /* end of source */
-

contrib/pngminus/test_pngminus.bat

@@ -1,4 +1,4 @@
-make -f makefile.tc3
+make
 call png2pnm.bat
 call pnm2png.bat
 

contrib/pngminus/test_pngminus.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-make -f makefile.std
+make
 sh png2pnm.sh
 sh pnm2png.sh
 

contrib/powerpc-vsx/linux.c

@@ -2,7 +2,6 @@
  *
  * 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
@@ -12,7 +11,7 @@
  * BUG REPORTS: png-mng-implement@sourceforge.net
  *
  * png_have_vsx implemented for Linux by reading the widely available
- * pseudo-file /proc/cpuinfo. 
+ * 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.

contrib/powerpc-vsx/linux_aux.c

@@ -2,7 +2,6 @@
  *
  * 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
@@ -23,14 +22,12 @@
 static int
 png_have_vsx(png_structp png_ptr)
 {
-
-   const unsigned long auxv = getauxval( AT_HWCAP );
+   unsigned long auxv = getauxval(AT_HWCAP);
 
    PNG_UNUSED(png_ptr)
 
-   if(auxv & (PPC_FEATURE_HAS_ALTIVEC|PPC_FEATURE_HAS_VSX ))
+   if(auxv & (PPC_FEATURE_HAS_ALTIVEC|PPC_FEATURE_HAS_VSX))
       return 1;
    else
       return 0;
 }
-

contrib/testpngs/makepngs.sh

@@ -1,12 +1,10 @@
-#!/bin/sh
-#
+#!/usr/bin/env bash
+
 # Make a set of test PNG files, MAKEPNG is the name of the makepng executable
 # built from contrib/libtests/makepng.c
 
 # Copyright (c) 2015 John Cunningham Bowler
 
-# Last changed in libpng 1.6.20 [December 3, 2015]
-
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
 # and license in png.h

contrib/tools/checksum-icc.c

@@ -2,8 +2,6 @@
  *
  * Copyright (c) 2013 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.0 [February 14, 2013]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -11,8 +9,8 @@
  * Generate crc32 and adler32 checksums of the given input files, used to
  * generate check-codes for use when matching ICC profiles within libpng.
  */
-#include <stdio.h>
 
+#include <stdio.h>
 #include <zlib.h>
 
 static int

contrib/tools/chkfmt.sh

@@ -1,21 +1,28 @@
 #!/bin/sh
 
-# chkfmt
+# chkfmt.sh
 #
-# COPYRIGHT: Written by John Cunningham Bowler, 2010.
+# COPYRIGHT:
+# Written by John Cunningham Bowler, 2010.
+# Revised by Cosmin Truta, 2022.
 # 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.
+# related or neighboring rights to this work.  The author published this work
+# from the United States.
 #
-# Check the format of the source files in the current directory - checks for a
-# line length of 80 characters max and no tab characters.
+# Check the format of the source files in the current directory:
+#
+#  * The lines should not exceed a predefined maximum length.
+#  * Tab characters should appear only where necessary (e.g. in makefiles).
 #
 # Optionally arguments are files or directories to check.
 #
-# -v: output the long lines (makes fixing them easier)
-# -e: spawn an editor for each file that needs a change ($EDITOR must be
-#     defined).  When using -e the script MUST be run from an interactive
-#     command line.
+#  -v: output the long lines (makes fixing them easier)
+#  -e: spawn an editor for each file that needs a change ($EDITOR must be
+#      defined).  When using -e the script MUST be run from an interactive
+#      command line.
+
+script_name=`basename "$0"`
+
 verbose=
 edit=
 vers=
@@ -32,14 +39,14 @@ test "$1" = "-e" && {
       # Copy the standard streams for the editor
       exec 3>&0 4>&1 5>&2
    else
-      echo "chkfmt -e: EDITOR must be defined" >&2
+      echo "$script_name -e: EDITOR must be defined" >&2
       exit 1
    fi
 }
 
 # Function to edit a single file - if the file isn't changed ask the user
-# whether or not to continue.  This stuff only works if the script is run from
-# the command line (otherwise, don't specify -e or you will be sorry).
+# whether or not to continue.  This stuff only works if the script is run
+# from the command line (otherwise, don't specify -e or you will be sorry).
 doed(){
    cp "$file" "$file".orig
    "$EDITOR" "$file" 0>&3 1>&4 2>&5 3>&- 4>&- 5>&- || exit 1
@@ -53,19 +60,22 @@ doed(){
    return 0
 }
 
-# In beta versions the version string which appears in files can be a little
-# long and cause spuriously overlong lines.  To avoid this substitute the version
-# string with a 'standard' version a.b.cc before checking for long lines.
+# In beta versions, the version string which appears in files can be a little
+# long and cause spuriously overlong lines.  To avoid this, substitute the
+# version string with a placeholder string "a.b.cc" before checking for long
+# lines.
+# (Starting from libpng version 1.6.36, we switched to a conventional Git
+# workflow, and we are no longer publishing beta versions.)
 if test -r png.h
 then
    vers="`sed -n -e \
    's/^#define PNG_LIBPNG_VER_STRING .\([0-9]\.[0-9]\.[0-9][0-9a-z]*\).$/\1/p' \
    png.h`"
-   echo "chkfmt: checking version $vers"
+   echo "$script_name: checking version $vers"
 fi
 if test -z "$vers"
 then
-   echo "chkfmt: png.h not found, ignoring version number" >&2
+   echo "$script_name: png.h not found, ignoring version number" >&2
 fi
 
 test -n "$1" || set -- .
@@ -89,13 +99,16 @@ find "$@" \( -type d \( -name '.git' -o -name '.libs' -o -name 'projects' \) \
          check_tabs=
          line_length=100;;
       *.awk)
-         # Includes literal tabs
+         # Allow literal tabs.
          check_tabs=
-         # The following is arbitrary
+         # Mainframe line printer, anyone?
          line_length=132;;
+      */ci_*.sh)
+         check_tabs=yes
+         line_length=100;;
       *contrib/*/*.[ch])
          check_tabs=yes
-         line_length=96;;
+         line_length=100;;
       *)
          check_tabs=yes
          line_length=80;;

contrib/tools/cvtcolor.c

@@ -1,7 +1,4 @@
-/*-
- * convert.c
- *
- * Last changed in libpng 1.6.0 [February 14, 2013]
+/* convert.c
  *
  * COPYRIGHT: Written by John Cunningham Bowler, 2013.
  * To the extent possible under law, the author has waived all copyright and
@@ -10,6 +7,7 @@
  *
  * Convert 8-bit sRGB or 16-bit linear values to another format.
  */
+
 #define _ISOC99_SOURCE 1
 
 #include <stdlib.h>

contrib/tools/genpng.c

@@ -1,4 +1,4 @@
-/*- genpng
+/* genpng
  *
  * COPYRIGHT: Written by John Cunningham Bowler, 2015.
  * Revised by Glenn Randers-Pehrson, 2017, to add buffer-size check.
@@ -69,6 +69,7 @@
  * joins are mitres; the outside of the lines are continued to the point of
  * intersection.
  */
+
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
@@ -453,7 +454,7 @@ check_square(const struct arg *arg, double x, double y)
  * { inside_circle_filled, check_circle_filled },
  * { inside_circle, check_circle }
  *
- * The functions here are analoguous to the square ones; however, they check
+ * The functions here are analogous to the square ones; however, they check
  * the corresponding ellipse as opposed to the rectangle.
  */
 static int

contrib/tools/intgamma.sh

@@ -1,13 +1,11 @@
 #!/bin/sh
-#
+
 # intgamma.sh
 #
-# Last changed in libpng 1.6.0 [February 14, 2013]
-#
 # COPYRIGHT: Written by John Cunningham Bowler, 2013.
 # 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.
+# related or neighboring rights to this work.  The author published this work
+# from the United States.
 #
 # Shell script to generate png.c 8-bit and 16-bit log tables (see the code in
 # png.c for details).
@@ -17,11 +15,11 @@
 # (0..255) value and a similar table for the exponent calculation.
 #
 # "bc" must be on the path when the script is executed, and the math library
-# (-lm) must be available
-#
-# function to print out a list of numbers as integers; the function truncates
-# the integers which must be one-per-line
-function print(){
+# (-lm) must be available.
+
+# Function to print out a list of numbers as integers; the function truncates
+# the integers which must be one-per-line.
+print(){
    awk 'BEGIN{
       str = ""
    }

contrib/tools/makesRGB.c

@@ -1,6 +1,4 @@
 /* makesRGB.c -- build sRGB-to-linear and linear-to-sRGB conversion tables
- *
- * Last changed in libpng 1.6.0 [February 14, 2013]
  *
  * COPYRIGHT: Written by John Cunningham Bowler, 2013.
  * To the extent possible under law, the author has waived all copyright and
@@ -14,6 +12,7 @@
  * approximation to the 8-bit sRGB encoded value.  Calculate the error in these
  * tables and display it.
  */
+
 #define _C99_SOURCE 1
 #include <stdio.h>
 #include <math.h>
@@ -388,7 +387,7 @@ main(int argc, char **argv)
 
    if (!test_only)
    {
-      printf("PNG_CONST png_uint_16 png_sRGB_table[256] =\n{\n   ");
+      printf("const png_uint_16 png_sRGB_table[256] =\n{\n   ");
       for (i=0; i<255; )
       {
          do
@@ -401,7 +400,7 @@ main(int argc, char **argv)
       printf("%d\n};\n\n", png_sRGB_table[i]);
 
 
-      printf("PNG_CONST png_uint_16 png_sRGB_base[512] =\n{\n   ");
+      printf("const png_uint_16 png_sRGB_base[512] =\n{\n   ");
       for (i=0; i<511; )
       {
          do
@@ -413,7 +412,7 @@ main(int argc, char **argv)
       }
       printf("%d\n};\n\n", png_sRGB_base[i]);
 
-      printf("PNG_CONST png_byte png_sRGB_delta[512] =\n{\n   ");
+      printf("const png_byte png_sRGB_delta[512] =\n{\n   ");
       for (i=0; i<511; )
       {
          do

contrib/tools/png-fix-itxt.c

@@ -1,8 +1,6 @@
-
-/* png-fix-itxt version 1.0.0
+/* png-fix-itxt
  *
  * Copyright 2015 Glenn Randers-Pehrson
- * Last changed in libpng 1.6.18 [July 23, 2015]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -10,7 +8,7 @@
  *
  * Usage:
  *
- *     png-fix-itxt.exe < bad.png > good.png
+ *     png-fix-itxt < bad.png > good.png
  *
  * Fixes a PNG file written with libpng-1.6.0 or 1.6.1 that has one or more
  * uncompressed iTXt chunks.  Assumes that the actual length is greater

contrib/tools/pngcp.c

@@ -1,8 +1,6 @@
 /* pngcp.c
  *
- * Copyright (c) 2016 John Cunningham Bowler
- *
- * Last changed in libpng 1.6.24 [August 4, 2016]
+ * Copyright (c) 2016,2022,2024 John Cunningham Bowler
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -14,7 +12,12 @@
  *
  * For a more extensive example that uses the transforms see
  * contrib/libtests/pngimage.c in the libpng distribution.
+ *
+ * This code is not intended for installation in a release system; the command
+ * line options are not documented and most of the behavior is intended for
+ * testing libpng performance, both speed and compression.
  */
+
 #include "pnglibconf.h" /* To find how libpng was configured. */
 
 #ifdef PNG_PNGCP_TIMING_SUPPORTED
@@ -85,16 +88,6 @@
 #  define voidcast(type, value) (value)
 #endif /* __cplusplus */
 
-#ifdef __GNUC__
-   /* Many versions of GCC erroneously report that local variables unmodified
-    * within the scope of a setjmp may be clobbered.  This hacks round the
-    * problem (sometimes) without harming other compilers.
-    */
-#  define gv volatile
-#else
-#  define gv
-#endif
-
 /* 'CLOCK_PROCESS_CPUTIME_ID' is one of the clock timers for clock_gettime.  It
  * need not be supported even when clock_gettime is available.  It returns the
  * 'CPU' time the process has consumed.  'CPU' time is assumed to include time
@@ -336,7 +329,7 @@ static const option options[] =
 #  define VLC(name) VLCIDAT(name) VLCiCCP(name) VLCzTXt(name)
 
 #  ifdef PNG_SW_COMPRESS_png_level
-      /* The libpng compression level isn't searched because it justs sets the
+      /* The libpng compression level isn't searched because it just sets the
        * other things that are searched!
        */
       VLO("compression", compression, 0)
@@ -392,6 +385,7 @@ struct display
 {
    jmp_buf          error_return;      /* Where to go to on error */
    unsigned int     errset;            /* error_return is set */
+   int              errlevel;          /* error level from longjmp */
 
    const char      *operation;         /* What is happening */
    const char      *filename;          /* The name of the original file */
@@ -503,10 +497,10 @@ display_init(struct display *dp)
 }
 
 static void
-display_clean_read(struct display *dp)
+display_clean_read(struct display *dp, int freeinfo)
 {
    if (dp->read_pp != NULL)
-      png_destroy_read_struct(&dp->read_pp, NULL, NULL);
+      png_destroy_read_struct(&dp->read_pp, freeinfo ? &dp->ip : NULL, NULL);
 
    if (dp->fp != NULL)
    {
@@ -517,7 +511,7 @@ display_clean_read(struct display *dp)
 }
 
 static void
-display_clean_write(struct display *dp)
+display_clean_write(struct display *dp, int freeinfo)
 {
    if (dp->fp != NULL)
    {
@@ -527,14 +521,14 @@ display_clean_write(struct display *dp)
    }
 
    if (dp->write_pp != NULL)
-      png_destroy_write_struct(&dp->write_pp, dp->tsp > 0 ? NULL : &dp->ip);
+      png_destroy_write_struct(&dp->write_pp, freeinfo ? &dp->ip : NULL);
 }
 
 static void
 display_clean(struct display *dp)
 {
-   display_clean_read(dp);
-   display_clean_write(dp);
+   display_clean_read(dp, 1/*freeinfo*/);
+   display_clean_write(dp, 1/*freeinfo*/);
    dp->output_file = NULL;
 
 #  if PNG_LIBPNG_VER < 10700 && defined PNG_TEXT_SUPPORTED
@@ -631,7 +625,10 @@ display_log(struct display *dp, error_level level, const char *fmt, ...)
    if (level > APP_FAIL || (level > ERRORS && !(dp->options & CONTINUE)))
    {
       if (dp->errset)
+      {
+         dp->errlevel = level;
          longjmp(dp->error_return, level);
+      }
 
       else
          exit(99);
@@ -735,7 +732,7 @@ option_index(struct display *dp, const char *opt, size_t len)
 static int
 get_option(struct display *dp, const char *opt, int *value)
 {
-   const png_byte i = option_index(dp, opt, strlen(opt));
+   png_byte i = option_index(dp, opt, strlen(opt));
 
    if (dp->entry[i]) /* option was set on command line */
    {
@@ -778,7 +775,7 @@ static void
 set_opt_string(struct display *dp, unsigned int sp)
    /* Add the appropriate option string to dp->curr. */
 {
-   dp->stack[sp].opt_string_end = set_opt_string_(dp, sp, dp->stack[sp].opt, 
+   dp->stack[sp].opt_string_end = set_opt_string_(dp, sp, dp->stack[sp].opt,
       options[dp->stack[sp].opt].values[dp->stack[sp].entry].name);
 }
 
@@ -789,7 +786,7 @@ record_opt(struct display *dp, png_byte opt, const char *entry_name)
     * numerical value.
     */
 {
-   const unsigned int sp = dp->csp; /* stack entry of next searched option */
+   unsigned int sp = dp->csp; /* stack entry of next searched option */
 
    if (sp >= dp->tsp)
    {
@@ -797,7 +794,7 @@ record_opt(struct display *dp, png_byte opt, const char *entry_name)
        * searched entry or the start of the dp->curr buffer if there is nothing
        * on the stack yet (sp == 0).
        */
-      const int offset = set_opt_string_(dp, sp, opt, entry_name);
+      int offset = set_opt_string_(dp, sp, opt, entry_name);
 
       if (sp > 0)
          dp->stack[sp-1].opt_string_end = offset;
@@ -1222,7 +1219,7 @@ advance_opt(struct display *dp, png_byte opt, int search)
 }
 
 static int
-getallopts_(struct display *dp, const png_byte opt, int *value, int record)
+getallopts_(struct display *dp, png_byte opt, int *value, int record)
    /* Like getop but iterate over all the values if the option was set to "all".
     */
 {
@@ -1259,7 +1256,7 @@ getsearchopts(struct display *dp, const char *opt_str, int *value)
    /* As above except that if the option was not set try a search */
 {
    png_byte istrat;
-   const png_byte opt = option_index(dp, opt_str, strlen(opt_str));
+   png_byte opt = option_index(dp, opt_str, strlen(opt_str));
    int record = options[opt].search;
    const char *entry_name;
 
@@ -1745,7 +1742,17 @@ read_function(png_structp pp, png_bytep data, size_t size)
 static void
 read_png(struct display *dp, const char *filename)
 {
-   display_clean_read(dp); /* safety */
+   /* This is an assumption of the code; it may happen if a previous write fails
+    * and there is a bug in the cleanup handling below (look for setjmp).
+    * Passing freeinfo==1 to display_clean_read below avoids a second error
+    * on dp->ip != NULL below.
+    */
+   if (dp->read_pp != NULL)
+   {
+      display_log(dp, APP_FAIL, "unexpected png_read_struct");
+      display_clean_read(dp, 1/*freeinfo*/); /* recovery */
+   }
+
    display_start_read(dp, filename);
 
    dp->read_pp = png_create_read_struct(PNG_LIBPNG_VER_STRING, dp,
@@ -1769,6 +1776,13 @@ read_png(struct display *dp, const char *filename)
          png_set_check_for_invalid_index(dp->read_pp, -1/*off completely*/);
 #  endif /* IGNORE_INDEX */
 
+   if (dp->ip != NULL)
+   {
+      /* UNEXPECTED: some problem in the display_clean function calls! */
+      display_log(dp, APP_FAIL, "read_png: freeing old info struct");
+      png_destroy_info_struct(dp->read_pp, &dp->ip);
+   }
+
    /* The png_read_png API requires us to make the info struct, but it does the
     * call to png_read_info.
     */
@@ -1848,7 +1862,14 @@ read_png(struct display *dp, const char *filename)
    }
 #endif /* FIX_INDEX */
 
-   display_clean_read(dp);
+   /* NOTE: dp->ip is where all the information about the PNG that was just read
+    * is stored.  It can be used to write and write again a single PNG file,
+    * however be aware that prior to libpng 1.7 text chunks could only be
+    * written once; this is a bug which would require a significant code rewrite
+    * to fix, it has been there in several versions of libpng (it was introduced
+    * to fix another bug involving duplicate writes of the text chunks.)
+    */
+   display_clean_read(dp, 0/*freeiinfo*/);
    dp->operation = "none";
 }
 
@@ -1975,7 +1996,21 @@ set_text_compression(struct display *dp)
 static void
 write_png(struct display *dp, const char *destname)
 {
-   display_clean_write(dp); /* safety */
+   /* If this test fails png_write_png would fail *silently* below; this
+    * is not helpful, so catch the problem now and give up:
+    */
+   if (dp->ip == NULL)
+      display_log(dp, INTERNAL_ERROR, "missing png_info");
+
+   /* This is an assumption of the code; it may happen if a previous
+    * write fails and there is a bug in the cleanup handling below.
+    */
+   if (dp->write_pp != NULL)
+   {
+      display_log(dp, APP_FAIL, "unexpected png_write_struct");
+      display_clean_write(dp, 0/*!freeinfo*/);
+   }
+
    display_start_write(dp, destname);
 
    dp->write_pp = png_create_write_struct(PNG_LIBPNG_VER_STRING, dp,
@@ -2073,10 +2108,6 @@ write_png(struct display *dp, const char *destname)
                destname == NULL ? "stdout" : destname, strerror(errno));
    }
 
-   /* Clean it on the way out - if control returns to the caller then the
-    * written_file contains the required data.
-    */
-   display_clean_write(dp);
    dp->operation = "none";
 }
 
@@ -2220,7 +2251,7 @@ cp_one_file(struct display *dp, const char *filename, const char *destname)
    strcpy(dp->best, dp->curr);
    dp->best_size = dp->write_size;
 
-   if (dp->nsp > 0) /* interating over lists */
+   if (dp->nsp > 0) /* iterating over lists */
    {
       char *tmpname, tmpbuf[(sizeof dp->namebuf) + 4];
       assert(dp->curr[0] == ' ' && dp->tsp > 0);
@@ -2243,6 +2274,10 @@ cp_one_file(struct display *dp, const char *filename, const char *destname)
       /* Loop to find the best option. */
       do
       {
+         /* Clean before each write_png; this just removes *dp->write_pp which
+          * cannot be reused.
+          */
+         display_clean_write(dp, 0/*!freeinfo*/);
          write_png(dp, tmpname);
 
          /* And compare the sizes (the write function makes sure write_size
@@ -2272,17 +2307,14 @@ cp_one_file(struct display *dp, const char *filename, const char *destname)
       /* Do this for the 'sizes' option so that it reports the correct size. */
       dp->write_size = dp->best_size;
    }
+
+   display_clean_write(dp, 1/*freeinfo*/);
 }
 
 static int
-cppng(struct display *dp, const char *file, const char *gv dest)
-   /* Exists solely to isolate the setjmp clobbers which some versions of GCC
-    * erroneously generate.
-    */
+cppng(struct display *dp, const char *file, const char *dest)
 {
-   int ret = setjmp(dp->error_return);
-
-   if (ret == 0)
+   if (setjmp(dp->error_return) == 0)
    {
       dp->errset = 1;
       cp_one_file(dp, file, dest);
@@ -2294,15 +2326,16 @@ cppng(struct display *dp, const char *file, const char *gv dest)
    {
       dp->errset = 0;
 
-      if (ret < ERRORS) /* shouldn't longjmp on warnings */
-         display_log(dp, INTERNAL_ERROR, "unexpected return code %d", ret);
+      if (dp->errlevel < ERRORS) /* shouldn't longjmp on warnings */
+         display_log(dp, INTERNAL_ERROR, "unexpected return code %d",
+               dp->errlevel);
 
-      return ret;
+      return dp->errlevel;
    }
 }
 
 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;
@@ -2379,7 +2412,7 @@ 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/tools/pngfix.c

@@ -1,7 +1,6 @@
 /* pngfix.c
  *
- * Last changed in libpng 1.6.31 [July 27, 2017]
- * Copyright (c) 2014-2017 John Cunningham Bowler
+ * Copyright (c) 2014-2017,2024 John Cunningham Bowler
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -10,6 +9,7 @@
  * Tool to check and fix the zlib inflate 'too far back' problem.
  * See the usage message for more information.
  */
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -20,19 +20,6 @@
 
 #define implies(x,y) assert(!(x) || (y))
 
-#ifdef __GNUC__
-   /* This is used to fix the error:
-    *
-    * pngfix.c:
-    * In function 'zlib_advance':
-    * pngfix.c:181:13: error: assuming signed overflow does not
-    *   occur when simplifying conditional to constant [-Werror=strict-overflow]
-    */
-#  define FIX_GCC volatile
-#else
-#  define FIX_GCC
-#endif
-
 #define PROGRAM_NAME "pngfix"
 
 /* Define the following to use this program against your installed libpng,
@@ -218,7 +205,7 @@ uarb_inc(uarb num, int in_digits, png_int_32 add)
     * in_digits+1 if add is known to be in the range -65535..65535.
     */
 {
-   FIX_GCC int out_digits = 0;
+   int out_digits = 0;
 
    while (out_digits < in_digits)
    {
@@ -263,7 +250,7 @@ uarb_add32(uarb num, int in_digits, png_uint_32 add)
 }
 
 static int
-uarb_mult_digit(uarb acc, int a_digits, uarb num, FIX_GCC int n_digits,
+uarb_mult_digit(uarb acc, int a_digits, uarb num, int n_digits,
    png_uint_16 val)
    /* Primitive one-digit multiply - 'val' must be 0..65535. Note that this
     * primitive is a multiply and accumulate - the result of *num * val is added
@@ -336,7 +323,7 @@ uarb_shift(uarb inout, int ndigits, unsigned int right_shift)
     * 1..15
     */
 {
-   FIX_GCC int i = ndigits;
+   int i = ndigits;
    png_uint_16 carry = 0;
 
    assert(right_shift >= 1 && right_shift <= 15);
@@ -351,7 +338,7 @@ uarb_shift(uarb inout, int ndigits, unsigned int right_shift)
       inout[i] = temp;
 
       /* The shift may reduce ndigits */
-      if (i == ndigits-1 && temp == 0)
+      if (i+1 == ndigits && temp == 0)
          ndigits = i;
    }
 
@@ -772,7 +759,7 @@ skip_chunk_type(const struct global *global, png_uint_32 type)
          return 0;
 
       /* Chunks that specify gamma encoding which should therefore only be
-       * removed the the user insists:
+       * removed if the user insists:
        */
       case png_gAMA: case png_sRGB:
          if (global->skip >= SKIP_ALL)
@@ -867,7 +854,7 @@ struct file
     * signature (in length,type).
     *
     * When a chunk control structure is instantiated these values are copied
-    * into the structure and can then be overritten with the data for the next
+    * into the structure and can then be overwritten with the data for the next
     * chunk.
     */
    fpos_t         data_pos;      /* Position of first byte of chunk data */
@@ -1005,10 +992,18 @@ file_end(struct file *file)
 
    if (file->out != NULL)
    {
-      /* NOTE: this is bitwise |, all the following functions must execute and
-       * must succeed.
+      /* On some systems 'fclose' deletes the FILE struct (making it
+       * inaccessbile).  There is no guarantee that fclose returns an error
+       * code from fflush or, indeed, from the FILE error indicator.  There is
+       * also no explicit (or clear) guarantee in the standard that anything
+       * other than a read or write operation sets the error indicator; fflush
+       * is not a read or write operation, so both conditions must be checked
+       * to ensure the close succeeded and in ANSI-C conformant code they must
+       * be checked before the fclose call.
        */
-      if (ferror(file->out) | fflush(file->out) | fclose(file->out))
+      const int err = fflush(file->out) || ferror(file->out);
+
+      if (fclose(file->out) || err)
       {
          perror(file->out_name);
          emit_error(file, READ_ERROR_CODE, "output write error");
@@ -1598,7 +1593,7 @@ chunk_init(struct chunk * const chunk, struct file * const file)
    chunk->chunk_length = file->length;
    chunk->chunk_type = file->type;
 
-   /* Compresssed/uncompressed size information (from the zlib control structure
+   /* Compressed/uncompressed size information (from the zlib control structure
     * that is used to check the compressed data in a chunk.)
     */
    chunk->uncompressed_digits = 0;
@@ -2514,7 +2509,7 @@ zlib_run(struct zlib *zlib)
        */
       for (;;)
       {
-         const unsigned int count = list->count;
+         unsigned int count = list->count;
          unsigned int i;
 
          for (i = 0; i<count; ++i)
@@ -2791,7 +2786,7 @@ process_chunk(struct file *file, png_uint_32 file_crc, png_uint_32 next_length,
     * to read_chunk.
     */
 {
-   const png_uint_32 type = file->type;
+   png_uint_32 type = file->type;
 
    if (file->global->verbose > 1)
    {
@@ -2929,7 +2924,7 @@ process_chunk(struct file *file, png_uint_32 file_crc, png_uint_32 next_length,
    }
 
    /* Control reaches this point if the chunk must be skipped.  For chunks other
-    * than IDAT this means that the zlib compressed data is fatally damanged and
+    * than IDAT this means that the zlib compressed data is fatally damaged and
     * the chunk will not be passed to libpng.  For IDAT it means that the end of
     * the IDAT stream has not yet been reached and we must handle the next
     * (IDAT) chunk.  If the LZ data in an IDAT stream cannot be read 'stop' must
@@ -3152,7 +3147,7 @@ read_chunk(struct file *file)
       }
    }
 
-   /* Control gets to here if the the stream seems invalid or damaged in some
+   /* Control gets to here if the stream seems invalid or damaged in some
     * way.  Either there was a problem reading all the expected data (this
     * chunk's data, its CRC and the length and type of the next chunk) or the
     * next chunk length/type are invalid.  Notice that the cases that end up
@@ -3710,7 +3705,7 @@ usage(const char *prog)
 "            practice most programs will ignore it.",
 "        bKGD [transform]: This is used by libpng transforms."
 "    --max=<number>:",
-"      Use IDAT chunks sized <number>.  If no number is given the the IDAT",
+"      Use IDAT chunks sized <number>.  If no number is given the IDAT",
 "      chunks will be the maximum size permitted; 2^31-1 bytes.  If the option",
 "      is omitted the original chunk sizes will not be changed.  When the",
 "      option is given --strip=unsafe is set automatically. This may be",
@@ -3961,6 +3956,14 @@ main(int argc, const char **argv)
       {
          size_t outlen = strlen(*argv);
 
+         if (outlen > FILENAME_MAX)
+         {
+            fprintf(stderr, "%s: output file name too long: %s%s%s\n",
+               prog, prefix, *argv, suffix ? suffix : "");
+            global.status_code |= WRITE_ERROR;
+            continue;
+         }
+
          if (outfile == NULL) /* else this takes precedence */
          {
             /* Consider the prefix/suffix options */
@@ -4046,4 +4049,4 @@ main(void)
    return 77;
 }
 #endif /* PNG_SETJMP_SUPPORTED */
-
+/* vi: set textwidth=80 shiftwidth=3 softtabstop=-1 expandtab: */

contrib/tools/reindent

@@ -1,25 +0,0 @@
-#!/bin/sh
-
-# reindent a libpng C source
-
-# COPYRIGHT: Written by Glenn Randers-Pehrson, 2016.
-# 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.
-
-# Usage:
-# reindent inputtabsize outputtabsize inputcontinuestring outputcontinuestring
-#
-# Assumes that continued lines begin with indentation plus one space, and
-# that continued comments begin with indentation plus " *".
-#
-# eg, to change libpng coding style from 3-space indentation with 4-space
-# continuations to 4-space indentation with 2-space continuations:
-#
-#  reindent 3 4 "\t " "  " < example.c > example.c_4_2
-# and to restore the file back to libpng coding style
-#  reindent 4 3 "  " "    " < example.c_4_2 > example.c_3_4
-
-unexpand --first-only --t $1 | \
-   sed -e "/^	*$3[^\*]/{s/$3/$4/}" | \
-   expand -t $2

contrib/tools/sRGB.h

@@ -1,7 +1,4 @@
-/*-
- * sRGB.h
- *
- * Last changed in libpng 1.6.0 [February 14, 2013]
+/* sRGB.h
  *
  * COPYRIGHT: Written by John Cunningham Bowler, 2013.
  * To the extent possible under law, the author has waived all copyright and
@@ -16,6 +13,7 @@
  * (in fact the source of the numbers is the wikipedia article at
  * https://en.wikipedia.org/wiki/SRGB).
  */
+
 static double
 sRGB_from_linear(double l)
 {

contrib/visupng/VisualPng.c

@@ -103,7 +103,7 @@ int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
         return 0;
     }
 
-    /* if filename given on commandline, store it */
+    /* if filename given on command line, store it */
     if ((szCmdLine != NULL) && (*szCmdLine != '\0'))
         if (szCmdLine[0] == '"')
             strncpy (szCmdFileName, szCmdLine + 1, strlen(szCmdLine) - 2);

depcomp

@@ -3,7 +3,7 @@
 
 scriptversion=2018-03-07.03; # UTC
 
-# Copyright (C) 1999-2018 Free Software Foundation, Inc.
+# Copyright (C) 1999-2021 Free Software Foundation, Inc.
 
 # 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

install-sh

@@ -1,7 +1,7 @@
 #!/bin/sh
 # install - install a program, script, or datafile
 
-scriptversion=2018-03-11.20; # UTC
+scriptversion=2023-11-23.18; # UTC
 
 # This originates from X11R5 (mit/util/scripts/install.sh), which was
 # later released in X11R6 (xc/config/util/install.sh) with the
@@ -69,6 +69,11 @@ posix_mkdir=
 # Desired mode of installed file.
 mode=0755
 
+# Create dirs (including intermediate dirs) using mode 755.
+# This is like GNU 'install' as of coreutils 8.32 (2020).
+mkdir_umask=22
+
+backupsuffix=
 chgrpcmd=
 chmodcmd=$chmodprog
 chowncmd=
@@ -99,19 +104,29 @@ Options:
      --version  display version info and exit.
 
   -c            (ignored)
-  -C            install only if different (preserve the last data modification time)
+  -C            install only if different (preserve data modification time)
   -d            create directories instead of installing files.
   -g GROUP      $chgrpprog installed files to GROUP.
   -m MODE       $chmodprog installed files to MODE.
   -o USER       $chownprog installed files to USER.
+  -p            pass -p to $cpprog.
   -s            $stripprog installed files.
+  -S SUFFIX     attempt to back up existing files, with suffix SUFFIX.
   -t DIRECTORY  install into DIRECTORY.
   -T            report an error if DSTFILE is a directory.
 
 Environment variables override the default commands:
   CHGRPPROG CHMODPROG CHOWNPROG CMPPROG CPPROG MKDIRPROG MVPROG
   RMPROG STRIPPROG
-"
+
+By default, rm is invoked with -f; when overridden with RMPROG,
+it's up to you to specify -f if you want it.
+
+If -S is not specified, no backups are attempted.
+
+Report bugs to <bug-automake@gnu.org>.
+GNU Automake home page: <https://www.gnu.org/software/automake/>.
+General help using GNU software: <https://www.gnu.org/gethelp/>."
 
 while test $# -ne 0; do
   case $1 in
@@ -137,8 +152,13 @@ while test $# -ne 0; do
     -o) chowncmd="$chownprog $2"
         shift;;
 
+    -p) cpprog="$cpprog -p";;
+
     -s) stripcmd=$stripprog;;
 
+    -S) backupsuffix="$2"
+        shift;;
+
     -t)
         is_target_a_directory=always
         dst_arg=$2
@@ -255,6 +275,10 @@ do
     dstdir=$dst
     test -d "$dstdir"
     dstdir_status=$?
+    # Don't chown directories that already exist.
+    if test $dstdir_status = 0; then
+      chowncmd=""
+    fi
   else
 
     # Waiting for this to be detected by the "$cpprog $src $dsttmp" command
@@ -301,22 +325,6 @@ do
   if test $dstdir_status != 0; then
     case $posix_mkdir in
       '')
-        # Create intermediate dirs using mode 755 as modified by the umask.
-        # This is like FreeBSD 'install' as of 1997-10-28.
-        umask=`umask`
-        case $stripcmd.$umask in
-          # Optimize common cases.
-          *[2367][2367]) mkdir_umask=$umask;;
-          .*0[02][02] | .[02][02] | .[02]) mkdir_umask=22;;
-
-          *[0-7])
-            mkdir_umask=`expr $umask + 22 \
-              - $umask % 100 % 40 + $umask % 20 \
-              - $umask % 10 % 4 + $umask % 2
-            `;;
-          *) mkdir_umask=$umask,go-w;;
-        esac
-
         # With -d, create the new directory with the user-specified mode.
         # Otherwise, rely on $mkdir_umask.
         if test -n "$dir_arg"; then
@@ -326,52 +334,49 @@ do
         fi
 
         posix_mkdir=false
-        case $umask in
-          *[123567][0-7][0-7])
-            # POSIX mkdir -p sets u+wx bits regardless of umask, which
-            # is incompatible with FreeBSD 'install' when (umask & 300) != 0.
-            ;;
-          *)
-            # Note that $RANDOM variable is not portable (e.g. dash);  Use it
-            # here however when possible just to lower collision chance.
-            tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
+	# The $RANDOM variable is not portable (e.g., dash).  Use it
+	# here however when possible just to lower collision chance.
+	tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
 
-            trap 'ret=$?; rmdir "$tmpdir/a/b" "$tmpdir/a" "$tmpdir" 2>/dev/null; exit $ret' 0
+	trap '
+	  ret=$?
+	  rmdir "$tmpdir/a/b" "$tmpdir/a" "$tmpdir" 2>/dev/null
+	  exit $ret
+	' 0
 
-            # Because "mkdir -p" follows existing symlinks and we likely work
-            # directly in world-writeable /tmp, make sure that the '$tmpdir'
-            # directory is successfully created first before we actually test
-            # 'mkdir -p' feature.
-            if (umask $mkdir_umask &&
-                $mkdirprog $mkdir_mode "$tmpdir" &&
-                exec $mkdirprog $mkdir_mode -p -- "$tmpdir/a/b") >/dev/null 2>&1
-            then
-              if test -z "$dir_arg" || {
-                   # Check for POSIX incompatibilities with -m.
-                   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
-                   # other-writable bit of parent directory when it shouldn't.
-                   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
-                   test_tmpdir="$tmpdir/a"
-                   ls_ld_tmpdir=`ls -ld "$test_tmpdir"`
-                   case $ls_ld_tmpdir in
-                     d????-?r-*) different_mode=700;;
-                     d????-?--*) different_mode=755;;
-                     *) false;;
-                   esac &&
-                   $mkdirprog -m$different_mode -p -- "$test_tmpdir" && {
-                     ls_ld_tmpdir_1=`ls -ld "$test_tmpdir"`
-                     test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
-                   }
-                 }
-              then posix_mkdir=:
-              fi
-              rmdir "$tmpdir/a/b" "$tmpdir/a" "$tmpdir"
-            else
-              # Remove any dirs left behind by ancient mkdir implementations.
-              rmdir ./$mkdir_mode ./-p ./-- "$tmpdir" 2>/dev/null
-            fi
-            trap '' 0;;
-        esac;;
+	# Because "mkdir -p" follows existing symlinks and we likely work
+	# directly in world-writeable /tmp, make sure that the '$tmpdir'
+	# directory is successfully created first before we actually test
+	# 'mkdir -p'.
+	if (umask $mkdir_umask &&
+	    $mkdirprog $mkdir_mode "$tmpdir" &&
+	    exec $mkdirprog $mkdir_mode -p -- "$tmpdir/a/b") >/dev/null 2>&1
+	then
+	  if test -z "$dir_arg" || {
+	       # Check for POSIX incompatibilities with -m.
+	       # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
+	       # other-writable bit of parent directory when it shouldn't.
+	       # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
+	       test_tmpdir="$tmpdir/a"
+	       ls_ld_tmpdir=`ls -ld "$test_tmpdir"`
+	       case $ls_ld_tmpdir in
+		 d????-?r-*) different_mode=700;;
+		 d????-?--*) different_mode=755;;
+		 *) false;;
+	       esac &&
+	       $mkdirprog -m$different_mode -p -- "$test_tmpdir" && {
+		 ls_ld_tmpdir_1=`ls -ld "$test_tmpdir"`
+		 test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
+	       }
+	     }
+	  then posix_mkdir=:
+	  fi
+	  rmdir "$tmpdir/a/b" "$tmpdir/a" "$tmpdir"
+	else
+	  # Remove any dirs left behind by ancient mkdir implementations.
+	  rmdir ./$mkdir_mode ./-p ./-- "$tmpdir" 2>/dev/null
+	fi
+	trap '' 0;;
     esac
 
     if
@@ -382,7 +387,7 @@ do
     then :
     else
 
-      # The umask is ridiculous, or mkdir does not conform to POSIX,
+      # mkdir does not conform to POSIX,
       # or it failed possibly due to a race condition.  Create the
       # directory the slow way, step by step, checking for races as we go.
 
@@ -411,7 +416,7 @@ do
           prefixes=
         else
           if $posix_mkdir; then
-            (umask=$mkdir_umask &&
+            (umask $mkdir_umask &&
              $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir") && break
             # Don't fail if two instances are running concurrently.
             test -d "$prefix" || exit 1
@@ -451,7 +456,18 @@ do
     trap 'ret=$?; rm -f "$dsttmp" "$rmtmp" && exit $ret' 0
 
     # Copy the file name to the temp name.
-    (umask $cp_umask && $doit_exec $cpprog "$src" "$dsttmp") &&
+    (umask $cp_umask &&
+     { test -z "$stripcmd" || {
+	 # Create $dsttmp read-write so that cp doesn't create it read-only,
+	 # which would cause strip to fail.
+	 if test -z "$doit"; then
+	   : >"$dsttmp" # No need to fork-exec 'touch'.
+	 else
+	   $doit touch "$dsttmp"
+	 fi
+       }
+     } &&
+     $doit_exec $cpprog "$src" "$dsttmp") &&
 
     # and set any options; do chmod last to preserve setuid bits.
     #
@@ -477,6 +493,13 @@ do
     then
       rm -f "$dsttmp"
     else
+      # If $backupsuffix is set, and the file being installed
+      # already exists, attempt a backup.  Don't worry if it fails,
+      # e.g., if mv doesn't support -f.
+      if test -n "$backupsuffix" && test -f "$dst"; then
+        $doit $mvcmd -f "$dst" "$dst$backupsuffix" 2>/dev/null
+      fi
+
       # Rename the file to the real destination.
       $doit $mvcmd -f "$dsttmp" "$dst" 2>/dev/null ||
 
@@ -491,9 +514,9 @@ do
         # file should still install successfully.
         {
           test ! -f "$dst" ||
-          $doit $rmcmd -f "$dst" 2>/dev/null ||
+          $doit $rmcmd "$dst" 2>/dev/null ||
           { $doit $mvcmd -f "$dst" "$rmtmp" 2>/dev/null &&
-            { $doit $rmcmd -f "$rmtmp" 2>/dev/null; :; }
+            { $doit $rmcmd "$rmtmp" 2>/dev/null; :; }
           } ||
           { echo "$0: cannot unlink or rename $dst" >&2
             (exit 1); exit 1

intel/filter_sse2_intrinsics.c

@@ -1,12 +1,11 @@
 
 /* filter_sse2_intrinsics.c - SSE2 optimized filter functions
  *
+ * Copyright (c) 2018 Cosmin Truta
  * Copyright (c) 2016-2017 Glenn Randers-Pehrson
  * Written by Mike Klein and Matt Sarett
  * Derived from arm/filter_neon_intrinsics.c
  *
- * Last changed in libpng 1.6.31 [July 27, 2017]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -29,39 +28,25 @@
  */
 
 static __m128i load4(const void* p) {
-   return _mm_cvtsi32_si128(*(const int*)p);
+   int tmp;
+   memcpy(&tmp, p, sizeof(tmp));
+   return _mm_cvtsi32_si128(tmp);
 }
 
 static void store4(void* p, __m128i v) {
-   *(int*)p = _mm_cvtsi128_si32(v);
+   int tmp = _mm_cvtsi128_si32(v);
+   memcpy(p, &tmp, sizeof(int));
 }
 
 static __m128i load3(const void* p) {
-   /* We'll load 2 bytes, then 1 byte,
-    * then mask them together, and finally load into SSE.
-    */
-   const png_uint_16* p01 = (png_const_uint_16p)p;
-   const png_byte*    p2  = (const png_byte*)(p01+1);
-
-   png_uint_32 v012 = (png_uint_32)(*p01)
-                    | (png_uint_32)(*p2) << 16;
-   return load4(&v012);
+   png_uint_32 tmp = 0;
+   memcpy(&tmp, p, 3);
+   return _mm_cvtsi32_si128(tmp);
 }
 
 static void store3(void* p, __m128i v) {
-   /* We'll pull from SSE as a 32-bit int, then write
-    * its bottom two bytes, then its third byte.
-    */
-   png_uint_32 v012;
-   png_uint_16* p01;
-   png_byte*    p2;
-
-   store4(&v012, v);
-
-   p01 = (png_uint_16p)p;
-   p2  = (png_byte*)(p01+1);
-   *p01 = (png_uint_16)v012;
-   *p2  = (png_byte)(v012 >> 16);
+   int tmp = _mm_cvtsi128_si32(v);
+   memcpy(p, &tmp, 3);
 }
 
 void png_read_filter_row_sub3_sse2(png_row_infop row_info, png_bytep row,
@@ -274,7 +259,7 @@ void png_read_filter_row_paeth3_sse2(png_row_infop row_info, png_bytep row,
       a = d; d = _mm_unpacklo_epi8(load4(row ), zero);
 
       /* (p-a) == (a+b-c - a) == (b-c) */
-   
+
       pa = _mm_sub_epi16(b,c);
 
       /* (p-b) == (a+b-c - b) == (a-c) */

intel/intel_init.c

@@ -1,12 +1,11 @@
 
 /* intel_init.c - SSE2 optimized filter functions
  *
+ * Copyright (c) 2018 Cosmin Truta
  * Copyright (c) 2016-2017 Glenn Randers-Pehrson
  * Written by Mike Klein and Matt Sarett, Google, Inc.
  * Derived from arm/arm_init.c
  *
- * 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