Harden a vestigial check against overflow inside png_zalloc

Reported-by: Sergio Atienza Pastor, MTP Métodos y Tecnología
Bump version to 1.6.51.git
2025-07-10 18:04:09 +02:00 · 2025-07-03 22:42:11 +03:00 · 2025-07-02 20:24:24 +03:00 · 2025-07-01 23:50:00 +03:00 · 2025-07-01 22:57:36 +03:00 · 2025-06-30 23:46:32 +03:00
226 changed files with 10630 additions and 6759 deletions
--- a/.appveyor.yml
+++ b/.appveyor.yml
@ -2,8 +2,8 @@ version: 1.6.x-{build}

 branches:
  except:
-    - /libpng[0-1][0-7]/
-    - /v[0-1][.][0-7][.][0-9]+/
+    - /libpng[0-1][0-8]/
+    - /v[0-1][.][0-8][.][0-9]+/

 image:
  - Visual Studio 2022
@ -48,6 +48,7 @@ install:
  - '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'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%AUTOMATION%"=="cmake" C:\msys64\usr\bin\pacman.exe -S --noconfirm mingw-w64-%ARCH%-cmake mingw-w64-%ARCH%-ninja'

 before_build:
  - 'if "%TOOLCHAIN%"=="vstudio" set CI_CMAKE_GENERATOR=Visual Studio 17 2022'
@ -58,11 +59,11 @@ before_build:
  - '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'
+  - 'if "%TOOLCHAIN%"=="llvm" set CI_CC=clang'
+  - 'if "%TOOLCHAIN%"=="msys2" set CI_CMAKE_GENERATOR=Ninja'
+  - 'if "%TOOLCHAIN%"=="msys2" set CI_CC=gcc'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%ARCH%"=="i686" set MSYSTEM=MINGW32'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%ARCH%"=="x86_64" set MSYSTEM=MINGW64'
  - 'set CI_CMAKE_BUILD_FLAGS=-j2'
  - 'set CI_CTEST_FLAGS=-j2'
  - 'set CI_MAKE_FLAGS=-j2'
@ -76,4 +77,5 @@ build_script:
  - '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
+  - 'C:\tools\vcpkg\installed'
+  - 'C:\msys64\var\cache\pacman'
--- a/.cmake-format.yaml
+++ b/.cmake-format.yaml
@ -0,0 +1,94 @@
+# https://pypi.org/project/cmakelang
+# https://github.com/cheshirekow/cmake_format
+
+# ----------------------
+# Options for formatting
+# ----------------------
+
+# How wide to allow formatted cmake files
+# TODO: Reflow the CMake files to allow setting the maximum line width to 100.
+line_width: 255
+
+# How many spaces to tab for indent
+tab_size: 2
+
+# If true, lines are indented using tab characters (utf-8 0x09) instead of
+# <tab_size> space characters (utf-8 0x20). In cases where the layout would
+# require a fractional tab character, the behavior of the fractional
+# indentation is governed by <fractional_tab_policy>
+use_tabchars: false
+
+# If <use_tabchars> is True, then the value of this variable indicates how
+# fractional indentions are handled during whitespace replacement. If set to
+# 'use-space', fractional indentation is left as spaces (utf-8 0x20). If set
+# to `round-up` fractional indentation is replaced with a single tab character
+# (utf-8 0x09) effectively shifting the column to the next tabstop
+fractional_tab_policy: "use-space"
+
+# Enable comment markup parsing and reflow
+enable_markup: false
+
+# -------------------
+# Options for linting
+# -------------------
+
+# Lint codes to disable
+disabled_codes: [
+  # TODO:
+  # Reconcile the CMake variable names with the patterns below, then
+  # re-enable the "invalid variable name XXX" messages.
+  "C0103",
+
+  # TODO:
+  # Add brief COMMENT arguments to the `add_custom_target` commands.
+  "C0113",
+]
+
+# Regular expression pattern describing valid function names
+function_pattern: "[0-9a-z_]+"
+
+# Regular expression pattern describing valid macro names
+macro_pattern: "[0-9A-Z_]+"
+
+# Regular expression pattern describing valid names for variables with global
+# (cache) scope
+global_var_pattern: "[A-Z][0-9A-Z_]+"
+
+# Regular expression pattern describing valid names for variables with global
+# scope (but internal semantic)
+internal_var_pattern: "_[A-Z][0-9A-Z_]+"
+
+# Regular expression pattern describing valid names for variables with local
+# scope
+local_var_pattern: "[a-z][a-z0-9_]+"
+
+# Regular expression pattern describing valid names for privatedirectory
+# variables
+private_var_pattern: "_[0-9a-z_]+"
+
+# Regular expression pattern describing valid names for public directory
+# variables
+public_var_pattern: "[A-Z][0-9A-Z_]+"
+
+# Regular expression pattern describing valid names for function/macro
+# arguments and loop variables.
+argument_var_pattern: "[a-z][a-z0-9_]+"
+
+# Regular expression pattern describing valid names for keywords used in
+# functions or macros
+keyword_pattern: "[A-Z][0-9A-Z_]+"
+
+# In the heuristic for C0201, how many conditionals to match within a loop in
+# before considering the loop a parser
+max_conditionals_custom_parser: 2
+
+# Require at least this many newlines between statements;
+# require no more than this many newlines between statements;
+# etc.
+min_statement_spacing: 1
+max_statement_spacing: 2
+max_returns: 6
+max_branches: 12
+max_arguments: 5
+max_localvars: 15
+max_statements: 50
--- a/.editorconfig
+++ b/.editorconfig
@ -8,29 +8,41 @@ insert_final_newline = true
 trim_trailing_whitespace = true

 [*.txt]
+indent_size = unset
 indent_style = space

 [*.[chS]]
+indent_size = 3
 indent_style = space
 max_doc_length = 80
 max_line_length = 80

 [*.dfa]
+indent_size = 3
 indent_style = space
 max_doc_length = 80
 max_line_length = 80

-[*.{awk,cmake}]
+[*.awk]
+indent_size = 3
 indent_style = space
 max_doc_length = 80
 max_line_length = 100

-[*.{in,sh}]
+[*.cmake]
+indent_size = 2
+indent_style = space
+max_doc_length = 80
+max_line_length = 100
+
+[*.sh]
+indent_size = 4
 indent_style = space
 max_doc_length = 100
 max_line_length = 100

-[{Makefile.in,ltmain.sh}]
+[{Makefile.in,aclocal.m4,ltmain.sh}]
+indent_size = unset
 indent_style = unset
 insert_final_newline = unset
 max_doc_length = unset
--- a/.editorconfig-checker.json
+++ b/.editorconfig-checker.json
@ -0,0 +1,9 @@
+{
+  "Disable": {
+    "IndentSize": true
+  },
+  "Exclude": [
+    ".git/",
+    "out/"
+  ]
+}
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@ -4,9 +4,11 @@ on:
  push:
    branches:
      - libpng16
+      - libpng18
  pull_request:
    branches:
      - libpng16
+      - libpng18

 jobs:
  lint:
@ -21,6 +23,8 @@ jobs:
          restore-keys: ${{ runner.os }}-pip-
      - name: Install yamllint
        run: pip install yamllint
+      - name: Install editorconfig-checker
+        uses: editorconfig-checker/action-editorconfig-checker@main
      - name: Check out the code
        uses: actions/checkout@v4
      - name: Run the linting script
--- a/.gitignore
+++ b/.gitignore
@ -31,6 +31,7 @@
 # Compiled executables
 *.app/
 *.exe
+a.out

 # Debug files
 *.dSYM/
@ -38,42 +39,121 @@
 *.pdb
 *.su

-# Libpng configuration and build artifacts
+# Tag files
+TAGS
+.TAGS
+!TAGS/
+tags
+.tags
+!tags/
+gtags.files
+GTAGS
+GRTAGS
+GPATH
+GSYMS
+cscope.files
+cscope.out
+cscope.*.out
+
+# Text editing and text processing artifacts
+\#*\#
+.\#*
+[._]*.sw[a-p]
+[._]sw[a-p]
+*.bak
+*.orig
+*.rej
+*.tmp
+*~
+
+# IDE files and directories
+## Eclipse
+.cproject/
+.project/
+.settings/
+## Embarcadero RAD Studio
+*.cbproj.*
+__recovery/
+## JetBrains
+.idea/
+## NetBeans
+nbbuild/
+nbdist/
+nbproject/
+## Visual Studio
+.vs/
+### Visual Studio user files
+*.rsuser
+*.sln.docstates
+*.suo
+*.user
+*.userprefs
+### Visual Studio cache files (for older versions)
+*.aps
+*.ncb
+*.opensdf
+*.sdf
+*.VC.db
+*.VC.opendb
+ipch/
+## Visual Studio Code
+.vscode/*
+!.vscode/extensions.json
+!.vscode/launch.json
+!.vscode/settings.json
+!.vscode/tasks.json
+## (Various)
+*.*cache
+*.cache*
+[._]*_history
+.history/
+[Bb]ackup*/
+
+# Build, test and CI output directories
+*[Dd]ebug/
+[Dd]ebug*/
+*[Rr]elease/
+[Rr]elease*/
+[._]build*/
+/[Bb]uild*/
+/[Oo]ut/
+
+# Libpng configuration and auxiliary build artifacts
 *.out
-.deps/
+*out.png
+[._]deps/
+[._]libs/
 .dirstamp
 /Makefile
 /autom4te.cache/
-/config.guess~
-/config.h.in~
+/config*~
+/config.h
 /config.log
 /config.status
-/config.sub~
-/configure~
-/install-sh~
-/libpng-config
-/libpng.pc
+/install*~
+/libpng*-config
+/libpng*.pc
 /libpng.vers
-/libpng16-config
-/libpng16.pc
 /libtool
 /stamp-h1
+CMake*.json
+!CMakePresets.json
+CMakeLists.txt.*
 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/
+# Libpng test programs, scripts and artifacts
+/test-suite.log
+/tests/*.log
+/tests/*.trs
+/png-fix-itxt
+/pngcp
+/pngfix
+/pngimage
+/pngstest
+/pngtest
+/pngunknown
+/pngvalid
+/timepng
--- a/.travis.yml
+++ b/.travis.yml
@ -1,34 +0,0 @@
-branches:
-  except:
-    - /libpng[0-1][0-7]/
-    - /v[0-1][.][0-7][.][0-9]+/
-
-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'
--- a/56
+++ b/56
@ -1,5 +1,13 @@
-libpng 1.6.43 - February 23, 2024
-=================================
+libpng 1.6.51.git
+=================
+
+This is a development version, not intended to be a public release.
+It will be replaced by a public release, or by another development
+version, at a later time.
+
+
+libpng 1.6.50 - July 1, 2025
+============================

 This is a public release of libpng, intended for use in production code.

@ -9,13 +17,13 @@ Files available for download

 Source files with LF line endings (for Unix/Linux):

- * libpng-1.6.43.tar.xz (LZMA-compressed, recommended)
- * libpng-1.6.43.tar.gz (deflate-compressed)
+ * libpng-1.6.50.tar.xz (LZMA-compressed, recommended)
+ * libpng-1.6.50.tar.gz (deflate-compressed)

 Source files with CRLF line endings (for Windows):

- * lpng1643.7z (LZMA-compressed, recommended)
- * lpng1643.zip (deflate-compressed)
+ * lpng1650.7z (LZMA-compressed, recommended)
+ * lpng1650.zip (deflate-compressed)

 Other information:

@ -25,36 +33,18 @@ Other information:
 * TRADEMARK.md


-Changes from version 1.6.42 to version 1.6.43
+Changes from version 1.6.49 to version 1.6.50
 ---------------------------------------------

- * Fixed the row width check in png_check_IHDR().
-   This corrected a bug that was specific to the 16-bit platforms,
-   and removed a spurious compiler warning from the 64-bit builds.
-   (Reported by Jacek Caban; fixed by John Bowler)
- * Added eXIf chunk support to the push-mode reader in pngpread.c.
-   (Contributed by Chris Blume)
- * Added contrib/pngexif for the benefit of the users who would like
-   to inspect the content of eXIf chunks.
- * Added contrib/conftest/basic.dfa, a basic build-time configuration.
+ * Improved the detection of the RVV Extension on the RISC-V platform.
+   (Contributed by Filip Wasil)
+ * Replaced inline ASM with C intrinsics in the RVV code.
+   (Contributed by Filip Wasil)
+ * Fixed a decoder defect in which unknown chunks trailing IDAT, set
+   to go through the unknown chunk handler, incorrectly triggered
+   out-of-place IEND errors.
   (Contributed by John Bowler)
- * Fixed a preprocessor condition in pngread.c that broke build-time
-   configurations like contrib/conftest/pngcp.dfa.
-   (Contributed by John Bowler)
- * Added CMake build support for LoongArch LSX.
-   (Contributed by GuXiWei)
- * Fixed a CMake build error that occurred under a peculiar state of the
-   dependency tree. This was a regression introduced in libpng-1.6.41.
-   (Contributed by Dan Rosser)
- * Marked the installed libpng headers as system headers in CMake.
-   (Contributed by Benjamin Buch)
- * Updated the build support for RISCOS.
-   (Contributed by Cameron Cawley)
- * Updated the makefiles to allow cross-platform builds to initialize
-   conventional make variables like AR and ARFLAGS.
- * Added various improvements to the CI scripts in areas like version
-   consistency verification and text linting.
- * Added version consistency verification to pngtest.c also.
+ * Fixed the CMake file for cross-platform builds that require `libm`.


 Send comments/corrections/commendations to png-mng-implement at lists.sf.net.
--- a/7
+++ b/7
@ -17,8 +17,10 @@ Authors, for copyright and licensing purposes.
 * James Yu
 * John Bowler
 * Kevin Bracey
+ * Lucas Chollet
 * Magnus Holmgren
 * Mandar Sahastrabuddhe
+ * Manfred Schlaegl
 * Mans Rullgard
 * Matt Sarett
 * Mike Klein
@ -39,8 +41,9 @@ Authors, for copyright and licensing purposes.
    - Zixu Wang (王子旭)
 * Arm Holdings
    - Richard Townsend
- * Google Inc.
+ * Google LLC
    - Dan Field
+    - Dragoș Tiselice
    - Leon Scroggins III
    - Matt Sarett
    - Mike Klein
@ -50,6 +53,8 @@ Authors, for copyright and licensing purposes.
    - GuXiWei (顾希伟)
    - JinBo (金波)
    - ZhangLixia (张利霞)
+ * Samsung Group
+    - Filip Wasil

 The build projects, the build scripts, the test scripts, and other
 files in the "projects", "scripts" and "tests" directories, have
--- a/84
+++ b/84
@ -6196,6 +6196,90 @@ Version 1.6.43 [February 23, 2024]
    consistency verification and text linting.
  Added version consistency verification to pngtest.c also.

+Version 1.6.44 [September 12, 2024]
+  Hardened calculations in chroma handling to prevent overflows, and
+    relaxed a constraint in cHRM validation to accomodate the standard
+    ACES AP1 set of color primaries.
+    (Contributed by John Bowler)
+  Removed the ASM implementation of ARM Neon optimizations and updated
+    the build accordingly. Only the remaining C implementation shall be
+    used from now on, thus ensuring the support of the PAC/BTI security
+    features on ARM64.
+    (Contributed by Ross Burton and John Bowler)
+  Fixed the pickup of the PNG_HARDWARE_OPTIMIZATIONS option in the
+    CMake build on FreeBSD/amd64. This is an important performance fix
+    on this platform.
+  Applied various fixes and improvements to the CMake build.
+    (Contributed by Eric Riff, Benjamin Buch and Erik Scholz)
+  Added fuzzing targets for the simplified read API.
+    (Contributed by Mikhail Khachayants)
+  Fixed a build error involving pngtest.c under a custom config.
+    This was a regression introduced in a code cleanup in libpng-1.6.43.
+    (Contributed by Ben Wagner)
+  Fixed and improved the config files for AppVeyor CI and Travis CI.
+
+Version 1.6.45 [January 7, 2025]
+  Added support for the cICP chunk.
+    (Contributed by Lucas Chollet and John Bowler)
+  Adjusted and improved various checks in colorspace calculations.
+    (Contributed by John Bowler)
+  Rearranged the write order of colorspace chunks for better conformance
+    with the PNG v3 draft specification.
+    (Contributed by John Bowler)
+  Raised the minimum required CMake version from 3.6 to 3.14.
+  Forked off a development branch for libpng version 1.8.
+
+Version 1.6.46 [January 23, 2025]
+  Added support for the mDCV and cLLI chunks.
+    (Contributed by John Bowler)
+  Fixed a build issue affecting C89 compilers.
+    This was a regression introduced in libpng-1.6.45.
+    (Contributed by John Bowler)
+  Added makefile.c89, specifically for testing C89 compilers.
+  Cleaned up contrib/pngminus: corrected an old typo, removed an old
+    workaround, and updated the CMake file.
+
+Version 1.6.47 [February 18, 2025]
+  Modified the behaviour of colorspace chunks in order to adhere
+    to the new precedence rules formulated in the latest draft of
+    the PNG Specification.
+    (Contributed by John Bowler)
+  Fixed a latent bug in `png_write_iCCP`.
+    This would have been a read-beyond-end-of-malloc vulnerability,
+    introduced early in the libpng-1.6.0 development, yet (fortunately!)
+    it was inaccessible before the above-mentioned modification of the
+    colorspace precedence rules, due to pre-existing colorspace checks.
+    (Reported by Bob Friesenhahn; fixed by John Bowler)
+
+Version 1.6.48 [April 30, 2025]
+  Fixed the floating-point version of the mDCv setter `png_set_mDCv`.
+    (Reported by Mohit Bakshi; fixed by John Bowler)
+  Added #error directives to discourage the inclusion of private
+    libpng implementation header files in PNG-supporting applications.
+  Added the CMake build option `PNG_LIBCONF_HEADER`, to be used as an
+    alternative to `DFA_XTRA`.
+  Removed the Travis CI configuration files, with heartfelt thanks for
+    their generous support of our project over the past five years!
+
+Version 1.6.49 [June 12, 2025]
+  Added SIMD-optimized code for the RISC-V Vector Extension (RVV).
+    (Contributed by Manfred Schlaegl, Dragos Tiselice and Filip Wasil)
+  Added various fixes and improvements to the build scripts and to
+    the sample code.
+
+Version 1.6.50 [July 1, 2025]
+  Improved the detection of the RVV Extension on the RISC-V platform.
+    (Contributed by Filip Wasil)
+  Replaced inline ASM with C intrinsics in the RVV code.
+    (Contributed by Filip Wasil)
+  Fixed a decoder defect in which unknown chunks trailing IDAT, set
+    to go through the unknown chunk handler, incorrectly triggered
+    out-of-place IEND errors.
+    (Contributed by John Bowler)
+  Fixed the CMake file for cross-platform builds that require `libm`.
+
+Version 1.6.51 [TODO]
+
 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
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
--- a/11
+++ b/11
@ -1,4 +1,3 @@
-
    Installing libpng

 Contents
@ -137,7 +136,7 @@ Your directory structure should look like this:
             depcomp, install-sh, mkinstalldirs, test-pngtest.sh, etc.
          contrib
             arm-neon, conftest, examples, gregbook, libtests, pngminim,
-             pngminus, pngsuite, tools, visupng
+             pngminus, pngsuite, tools, visupng, riscv-rvv
          projects
             owatcom, visualc71, vstudio
          scripts
@ -290,6 +289,7 @@ such as one of
   --enable-mips-msa=yes
   --enable-intel-sse=yes
   --enable-powerpc-vsx=yes
+   --enable-riscv-rvv=yes

 or enable them all at once with

@ -302,6 +302,7 @@ or more of
   CPPFLAGS += "-DPNG_MIPS_MSA"
   CPPFLAGS += "-DPNG_INTEL_SSE"
   CPPFLAGS += "-DPNG_POWERPC_VSX"
+   CPPFLAGS += "-DPNG_RISCV_RVV"

 See for example scripts/makefile.linux-opt

@ -318,13 +319,15 @@ to disable a particular one,
 or via compiler-command options such as

   CPPFLAGS += "-DPNG_ARM_NEON_OPT=0, -DPNG_MIPS_MSA_OPT=0,
-   -DPNG_INTEL_SSE_OPT=0, -DPNG_POWERPC_VSX_OPT=0"
+   -DPNG_INTEL_SSE_OPT=0, -DPNG_POWERPC_VSX_OPT=0,
+   -DPNG_RISCV_RVV_OPT=0"

 If you are using cmake, hardware optimizations are "on"
 by default. To disable them, use

    cmake . -DPNG_ARM_NEON=no -DPNG_INTEL_SSE=no \
-            -DPNG_MIPS_MSA=no -DPNG_POWERPC_VSX=no
+            -DPNG_MIPS_MSA=no -DPNG_POWERPC_VSX=no \
+            -DPNG_RISCV_RVV=no

 or disable them all at once with

--- a/4
+++ b/4
@ -4,8 +4,8 @@ COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
 PNG Reference Library License version 2
 ---------------------------------------

- * Copyright (c) 1995-2024 The PNG Reference Library Authors.
- * Copyright (c) 2018-2024 Cosmin Truta.
+ * Copyright (c) 1995-2025 The PNG Reference Library Authors.
+ * Copyright (c) 2018-2025 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.
--- a/Makefile.am
+++ b/Makefile.am
@ -1,6 +1,6 @@
 # Makefile.am, the source file for Makefile.in (and hence Makefile), is
 #
-# Copyright (c) 2018-2024 Cosmin Truta
+# Copyright (c) 2018-2025 Cosmin Truta
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
@ -108,7 +108,7 @@ 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_intrinsics.c \
 	arm/palette_neon_intrinsics.c
 endif

@ -134,13 +134,20 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += powerpc/powerpc_init.c\
        powerpc/filter_vsx_intrinsics.c
 endif

+if PNG_RISCV_RVV
+noinst_LTLIBRARIES= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv.la
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_SOURCES = riscv/riscv_init.c\
+        riscv/filter_rvv_intrinsics.c
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_CFLAGS = -march=rv64gv
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv.la
+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
@ -163,6 +170,10 @@ else
  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.sym
 endif

+if PNG_RISCV_RVV
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES += libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv.la
+endif
+
 if PNG_LOONGARCH_LSX
  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES += libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
 endif
@ -199,7 +210,7 @@ MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.guess config.h.in \
 config.sub configure depcomp install-sh ltmain.sh missing

 # PNG_COPTS give extra options for the C compiler to be used on all compilation
-# steps (unless targe_CFLAGS is specified; that will take precedence over
+# steps (unless target_CFLAGS is specified; that will take precedence over
 # AM_CFLAGS)
 PNG_COPTS = @PNG_COPTS@
 AM_CFLAGS = ${PNG_COPTS}
--- a/Makefile.in
+++ b/Makefile.in
@ -1,7 +1,7 @@
-# Makefile.in generated by automake 1.16.5 from Makefile.am.
+# Makefile.in generated by automake 1.18.1 from Makefile.am.
 # @configure_input@

-# Copyright (C) 1994-2021 Free Software Foundation, Inc.
+# Copyright (C) 1994-2025 Free Software Foundation, Inc.

 # This Makefile.in is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -16,7 +16,7 @@

 # Makefile.am, the source file for Makefile.in (and hence Makefile), is
 #
-# Copyright (c) 2018-2024 Cosmin Truta
+# Copyright (c) 2018-2025 Cosmin Truta
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
@ -83,6 +83,8 @@ am__make_running_with_option = \
  test $$has_opt = yes
 am__make_dryrun = (target_option=n; $(am__make_running_with_option))
 am__make_keepgoing = (target_option=k; $(am__make_running_with_option))
+am__rm_f = rm -f $(am__rm_f_notfound)
+am__rm_rf = rm -rf $(am__rm_f_notfound)
 pkgdatadir = $(datadir)/@PACKAGE@
 pkglibdir = $(libdir)/@PACKAGE@
 pkglibexecdir = $(libexecdir)/@PACKAGE@
@ -108,7 +110,7 @@ host_triplet = @host@
@ENABLE_TOOLS_TRUE@bin_PROGRAMS = pngfix$(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_intrinsics.c \
@PNG_ARM_NEON_TRUE@	arm/palette_neon_intrinsics.c

@PNG_MIPS_MSA_TRUE@am__append_3 = mips/mips_init.c\
@ -128,8 +130,9 @@ host_triplet = @host@
@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_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@'
+@PNG_RISCV_RVV_TRUE@am__append_11 = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv.la
+@PNG_LOONGARCH_LSX_TRUE@am__append_12 = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+@DO_PNG_PREFIX_TRUE@am__append_13 = -DPNG_PREFIX='@PNG_PREFIX@'
 subdir = .
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/scripts/autoconf/libtool.m4 \
@ -177,10 +180,9 @@ am__base_list = \
  sed '$$!N;$$!N;$$!N;$$!N;$$!N;$$!N;$$!N;s/\n/ /g' | \
  sed '$$!N;$$!N;$$!N;$$!N;s/\n/ /g'
 am__uninstall_files_from_dir = { \
-  test -z "$$files" \
-    || { test ! -d "$$dir" && test ! -f "$$dir" && test ! -r "$$dir"; } \
-    || { echo " ( cd '$$dir' && rm -f" $$files ")"; \
-         $(am__cd) "$$dir" && rm -f $$files; }; \
+  { test ! -d "$$dir" && test ! -f "$$dir" && test ! -r "$$dir"; } \
+  || { echo " ( cd '$$dir' && rm -f" $$files ")"; \
+       $(am__cd) "$$dir" && echo $$files | $(am__xargs_n) 40 $(am__rm_f); }; \
  }
 LTLIBRARIES = $(lib_LTLIBRARIES) $(noinst_LTLIBRARIES)
 am__libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES_DIST = png.c \
@ -188,13 +190,13 @@ am__libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES_DIST = png.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 \
-	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
+	arm/filter_neon_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@am__objects_1 = arm/arm_init.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 \
@ -238,6 +240,18 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_LINK = $(LIBTOOL) $(AM_V_lt) \
 	$(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 =
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_LIBADD =
+am__libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_SOURCES_DIST =  \
+	riscv/riscv_init.c riscv/filter_rvv_intrinsics.c
+@PNG_RISCV_RVV_TRUE@am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_OBJECTS = riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.lo \
+@PNG_RISCV_RVV_TRUE@	riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.lo
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_OBJECTS =  \
+	$(am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_OBJECTS)
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_LINK = $(LIBTOOL) $(AM_V_lt) \
+	--tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=link \
+	$(CCLD) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_CFLAGS) \
+	$(CFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@
+@PNG_RISCV_RVV_TRUE@am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_rpath =
 am__png_fix_itxt_SOURCES_DIST = contrib/tools/png-fix-itxt.c
@ENABLE_TOOLS_TRUE@am_png_fix_itxt_OBJECTS =  \
@ENABLE_TOOLS_TRUE@	contrib/tools/png-fix-itxt.$(OBJEXT)
@ -312,7 +326,7 @@ am__depfiles_remade = ./$(DEPDIR)/png.Plo ./$(DEPDIR)/pngerror.Plo \
 	./$(DEPDIR)/pngtest.Po ./$(DEPDIR)/pngtrans.Plo \
 	./$(DEPDIR)/pngwio.Plo ./$(DEPDIR)/pngwrite.Plo \
 	./$(DEPDIR)/pngwtran.Plo ./$(DEPDIR)/pngwutil.Plo \
-	arm/$(DEPDIR)/arm_init.Plo arm/$(DEPDIR)/filter_neon.Plo \
+	arm/$(DEPDIR)/arm_init.Plo \
 	arm/$(DEPDIR)/filter_neon_intrinsics.Plo \
 	arm/$(DEPDIR)/palette_neon_intrinsics.Plo \
 	contrib/libtests/$(DEPDIR)/pngimage.Po \
@ -331,18 +345,10 @@ am__depfiles_remade = ./$(DEPDIR)/png.Plo ./$(DEPDIR)/pngerror.Plo \
 	mips/$(DEPDIR)/filter_msa_intrinsics.Plo \
 	mips/$(DEPDIR)/mips_init.Plo \
 	powerpc/$(DEPDIR)/filter_vsx_intrinsics.Plo \
-	powerpc/$(DEPDIR)/powerpc_init.Plo
+	powerpc/$(DEPDIR)/powerpc_init.Plo \
+	riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.Plo \
+	riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.Plo
 am__mv = mv -f
-CPPASCOMPILE = $(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) \
-	$(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CCASFLAGS) $(CCASFLAGS)
-LTCPPASCOMPILE = $(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) \
-	$(LIBTOOLFLAGS) --mode=compile $(CCAS) $(DEFS) \
-	$(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) \
-	$(AM_CCASFLAGS) $(CCASFLAGS)
-AM_V_CPPAS = $(am__v_CPPAS_@AM_V@)
-am__v_CPPAS_ = $(am__v_CPPAS_@AM_DEFAULT_V@)
-am__v_CPPAS_0 = @echo "  CPPAS   " $@;
-am__v_CPPAS_1 = 
 COMPILE = $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) \
 	$(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)
 LTCOMPILE = $(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) \
@ -364,12 +370,14 @@ 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) \
+	$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_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) \
 	$(am__libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_SOURCES_DIST) \
+	$(am__libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_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) \
@ -513,12 +521,13 @@ am__sh_e_setup = case $$- in *e*) set +e;; esac
 # Default flags passed to test drivers.
 am__common_driver_flags = \
  --color-tests "$$am__color_tests" \
+  $$am__collect_skipped_logs \
  --enable-hard-errors "$$am__enable_hard_errors" \
  --expect-failure "$$am__expect_failure"
 # To be inserted before the command running the test.  Creates the
 # directory for the log if needed.  Stores in $dir the directory
 # containing $f, in $tst the test, in $log the log.  Executes the
-# developer- defined test setup AM_TESTS_ENVIRONMENT (if any), and
+# developer-defined test setup AM_TESTS_ENVIRONMENT (if any), and
 # passes TESTS_ENVIRONMENT.  Set up options for the wrapper that
 # will run the test scripts (or their associated LOG_COMPILER, if
 # thy have one).
@ -537,6 +546,11 @@ if test -f "./$$f"; then dir=./;			\
 elif test -f "$$f"; then dir=;				\
 else dir="$(srcdir)/"; fi;				\
 tst=$$dir$$f; log='$@'; 				\
+if test -n '$(IGNORE_SKIPPED_LOGS)'; then		\
+  am__collect_skipped_logs='--collect-skipped-logs no';	\
+else							\
+  am__collect_skipped_logs='';				\
+fi;							\
 if test -n '$(DISABLE_HARD_ERRORS)'; then		\
  am__enable_hard_errors=no; 				\
 else							\
@ -592,20 +606,22 @@ distdir = $(PACKAGE)-$(VERSION)
 top_distdir = $(distdir)
 am__remove_distdir = \
  if test -d "$(distdir)"; then \
-    find "$(distdir)" -type d ! -perm -200 -exec chmod u+w {} ';' \
-      && rm -rf "$(distdir)" \
+    find "$(distdir)" -type d ! -perm -700 -exec chmod u+rwx {} ';' \
+      ; rm -rf "$(distdir)" \
      || { sleep 5 && rm -rf "$(distdir)"; }; \
  else :; fi
 am__post_remove_distdir = $(am__remove_distdir)
 DIST_ARCHIVES = $(distdir).tar.gz $(distdir).tar.xz
-GZIP_ENV = --best
+GZIP_ENV = -9
 DIST_TARGETS = dist-xz dist-gzip
 # Exists only to be overridden by the user if desired.
 AM_DISTCHECK_DVI_TARGET = dvi
 distuninstallcheck_listfiles = find . -type f -print
 am__distuninstallcheck_listfiles = $(distuninstallcheck_listfiles) \
  | sed 's|^\./|$(prefix)/|' | grep -v '$(infodir)/dir$$'
-distcleancheck_listfiles = find . -type f -print
+distcleancheck_listfiles = \
+  find . \( -type f -a \! \
+            \( -name .nfs* -o -name .smb* -o -name .__afs* \) \) -print

 #distribute headers in /usr/include/libpng/*
 pkgincludedir = $(includedir)/$(PNGLIB_BASENAME)
@ -688,7 +704,7 @@ PNGLIB_RELEASE = @PNGLIB_RELEASE@
 PNGLIB_VERSION = @PNGLIB_VERSION@

 # PNG_COPTS give extra options for the C compiler to be used on all compilation
-# steps (unless targe_CFLAGS is specified; that will take precedence over
+# steps (unless target_CFLAGS is specified; that will take precedence over
 # AM_CFLAGS)
 PNG_COPTS = @PNG_COPTS@
 PNG_PREFIX = @PNG_PREFIX@
@ -709,8 +725,10 @@ ac_ct_DUMPBIN = @ac_ct_DUMPBIN@
 am__include = @am__include@
 am__leading_dot = @am__leading_dot@
 am__quote = @am__quote@
+am__rm_f_notfound = @am__rm_f_notfound@
 am__tar = @am__tar@
 am__untar = @am__untar@
+am__xargs_n = @am__xargs_n@

 # generate the -config scripts if required
 binconfigs = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
@ -826,21 +844,28 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c \
 	$(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_RISCV_RVV_TRUE@noinst_LTLIBRARIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv.la
+@PNG_RISCV_RVV_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_SOURCES = riscv/riscv_init.c\
+@PNG_RISCV_RVV_TRUE@        riscv/filter_rvv_intrinsics.c
+
+@PNG_RISCV_RVV_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_CFLAGS = -march=rv64gv
+@PNG_LOONGARCH_LSX_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+@PNG_RISCV_RVV_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv.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_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_FALSE@	libpng.sym $(am__append_11) \
+@HAVE_LD_VERSION_SCRIPT_FALSE@	$(am__append_12)
@HAVE_LD_VERSION_SCRIPT_TRUE@libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES =  \
-@HAVE_LD_VERSION_SCRIPT_TRUE@	libpng.vers $(am__append_11)
+@HAVE_LD_VERSION_SCRIPT_TRUE@	libpng.vers $(am__append_11) \
+@HAVE_LD_VERSION_SCRIPT_TRUE@	$(am__append_12)
 pkginclude_HEADERS = png.h pngconf.h
 nodist_pkginclude_HEADERS = pnglibconf.h
 pkgconfig_DATA = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc
@ -874,7 +899,7 @@ SUFFIXES = .chk .out
 SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0' \
 	-DPNGLIB_VERSION='@PNGLIB_VERSION@' \
 	-DSYMBOL_PREFIX='$(SYMBOL_PREFIX)' -DPNG_NO_USE_READ_MACROS \
-	-DPNG_BUILDING_SYMBOL_TABLE $(am__append_12)
+	-DPNG_BUILDING_SYMBOL_TABLE $(am__append_13)

 # 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
@ -885,7 +910,7 @@ all: $(BUILT_SOURCES) config.h
 	$(MAKE) $(AM_MAKEFLAGS) all-am

 .SUFFIXES:
-.SUFFIXES: .chk .out .S .c .lo .log .o .obj .test .test$(EXEEXT) .trs
+.SUFFIXES: .chk .out .c .lo .log .o .obj .test .test$(EXEEXT) .trs
 am--refresh: Makefile
 	@:
 $(srcdir)/Makefile.in: @MAINTAINER_MODE_TRUE@ $(srcdir)/Makefile.am  $(am__configure_deps)
@ -925,12 +950,12 @@ config.h: stamp-h1
 	@test -f $@ || $(MAKE) $(AM_MAKEFLAGS) stamp-h1

 stamp-h1: $(srcdir)/config.h.in $(top_builddir)/config.status
-	@rm -f stamp-h1
-	cd $(top_builddir) && $(SHELL) ./config.status config.h
+	$(AM_V_at)rm -f stamp-h1
+	$(AM_V_GEN)cd $(top_builddir) && $(SHELL) ./config.status config.h
 $(srcdir)/config.h.in: @MAINTAINER_MODE_TRUE@ $(am__configure_deps) 
-	($(am__cd) $(top_srcdir) && $(AUTOHEADER))
-	rm -f stamp-h1
-	touch $@
+	$(AM_V_GEN)($(am__cd) $(top_srcdir) && $(AUTOHEADER))
+	$(AM_V_at)rm -f stamp-h1
+	$(AM_V_at)touch $@

 distclean-hdr:
 	-rm -f config.h stamp-h1
@ -977,25 +1002,15 @@ uninstall-binPROGRAMS:
 	`; \
 	test -n "$$list" || exit 0; \
 	echo " ( cd '$(DESTDIR)$(bindir)' && rm -f" $$files ")"; \
-	cd "$(DESTDIR)$(bindir)" && rm -f $$files
+	cd "$(DESTDIR)$(bindir)" && $(am__rm_f) $$files

 clean-binPROGRAMS:
-	@list='$(bin_PROGRAMS)'; test -n "$$list" || exit 0; \
-	echo " rm -f" $$list; \
-	rm -f $$list || exit $$?; \
-	test -n "$(EXEEXT)" || exit 0; \
-	list=`for p in $$list; do echo "$$p"; done | sed 's/$(EXEEXT)$$//'`; \
-	echo " rm -f" $$list; \
-	rm -f $$list
+	$(am__rm_f) $(bin_PROGRAMS)
+	test -z "$(EXEEXT)" || $(am__rm_f) $(bin_PROGRAMS:$(EXEEXT)=)

 clean-checkPROGRAMS:
-	@list='$(check_PROGRAMS)'; test -n "$$list" || exit 0; \
-	echo " rm -f" $$list; \
-	rm -f $$list || exit $$?; \
-	test -n "$(EXEEXT)" || exit 0; \
-	list=`for p in $$list; do echo "$$p"; done | sed 's/$(EXEEXT)$$//'`; \
-	echo " rm -f" $$list; \
-	rm -f $$list
+	$(am__rm_f) $(check_PROGRAMS)
+	test -z "$(EXEEXT)" || $(am__rm_f) $(check_PROGRAMS:$(EXEEXT)=)

 install-libLTLIBRARIES: $(lib_LTLIBRARIES)
 	@$(NORMAL_INSTALL)
@ -1022,44 +1037,39 @@ uninstall-libLTLIBRARIES:
 	done

 clean-libLTLIBRARIES:
-	-test -z "$(lib_LTLIBRARIES)" || rm -f $(lib_LTLIBRARIES)
+	-$(am__rm_f) $(lib_LTLIBRARIES)
 	@list='$(lib_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}; \
-	}
+	echo rm -f $${locs}; \
+	$(am__rm_f) $${locs}

 clean-noinstLTLIBRARIES:
-	-test -z "$(noinst_LTLIBRARIES)" || rm -f $(noinst_LTLIBRARIES)
+	-$(am__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}; \
-	}
+	echo rm -f $${locs}; \
+	$(am__rm_f) $${locs}
 arm/$(am__dirstamp):
 	@$(MKDIR_P) arm
-	@: > arm/$(am__dirstamp)
+	@: >>arm/$(am__dirstamp)
 arm/$(DEPDIR)/$(am__dirstamp):
 	@$(MKDIR_P) arm/$(DEPDIR)
-	@: > arm/$(DEPDIR)/$(am__dirstamp)
+	@: >>arm/$(DEPDIR)/$(am__dirstamp)
 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/$(am__dirstamp)
+	@: >>mips/$(am__dirstamp)
 mips/$(DEPDIR)/$(am__dirstamp):
 	@$(MKDIR_P) mips/$(DEPDIR)
-	@: > mips/$(DEPDIR)/$(am__dirstamp)
+	@: >>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)
@ -1067,20 +1077,20 @@ mips/filter_mmi_inline_assembly.lo: mips/$(am__dirstamp) \
 	mips/$(DEPDIR)/$(am__dirstamp)
 intel/$(am__dirstamp):
 	@$(MKDIR_P) intel
-	@: > intel/$(am__dirstamp)
+	@: >>intel/$(am__dirstamp)
 intel/$(DEPDIR)/$(am__dirstamp):
 	@$(MKDIR_P) intel/$(DEPDIR)
-	@: > intel/$(DEPDIR)/$(am__dirstamp)
+	@: >>intel/$(DEPDIR)/$(am__dirstamp)
 intel/intel_init.lo: intel/$(am__dirstamp) \
 	intel/$(DEPDIR)/$(am__dirstamp)
 intel/filter_sse2_intrinsics.lo: intel/$(am__dirstamp) \
 	intel/$(DEPDIR)/$(am__dirstamp)
 powerpc/$(am__dirstamp):
 	@$(MKDIR_P) powerpc
-	@: > powerpc/$(am__dirstamp)
+	@: >>powerpc/$(am__dirstamp)
 powerpc/$(DEPDIR)/$(am__dirstamp):
 	@$(MKDIR_P) powerpc/$(DEPDIR)
-	@: > powerpc/$(DEPDIR)/$(am__dirstamp)
+	@: >>powerpc/$(DEPDIR)/$(am__dirstamp)
 powerpc/powerpc_init.lo: powerpc/$(am__dirstamp) \
 	powerpc/$(DEPDIR)/$(am__dirstamp)
 powerpc/filter_vsx_intrinsics.lo: powerpc/$(am__dirstamp) \
@ -1090,10 +1100,10 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la: $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_O
 	$(AM_V_CCLD)$(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/$(am__dirstamp)
 loongarch/$(DEPDIR)/$(am__dirstamp):
 	@$(MKDIR_P) loongarch/$(DEPDIR)
-	@: > loongarch/$(DEPDIR)/$(am__dirstamp)
+	@: >>loongarch/$(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:  \
@ -1101,12 +1111,25 @@ loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo:  \

 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) $(LIBS)
+riscv/$(am__dirstamp):
+	@$(MKDIR_P) riscv
+	@: >>riscv/$(am__dirstamp)
+riscv/$(DEPDIR)/$(am__dirstamp):
+	@$(MKDIR_P) riscv/$(DEPDIR)
+	@: >>riscv/$(DEPDIR)/$(am__dirstamp)
+riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.lo:  \
+	riscv/$(am__dirstamp) riscv/$(DEPDIR)/$(am__dirstamp)
+riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.lo:  \
+	riscv/$(am__dirstamp) riscv/$(DEPDIR)/$(am__dirstamp)
+
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv.la: $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_OBJECTS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_DEPENDENCIES) $(EXTRA_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_DEPENDENCIES) 
+	$(AM_V_CCLD)$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_LINK) $(am_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_rpath) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_OBJECTS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la_LIBADD) $(LIBS)
 contrib/tools/$(am__dirstamp):
 	@$(MKDIR_P) contrib/tools
-	@: > contrib/tools/$(am__dirstamp)
+	@: >>contrib/tools/$(am__dirstamp)
 contrib/tools/$(DEPDIR)/$(am__dirstamp):
 	@$(MKDIR_P) contrib/tools/$(DEPDIR)
-	@: > contrib/tools/$(DEPDIR)/$(am__dirstamp)
+	@: >>contrib/tools/$(DEPDIR)/$(am__dirstamp)
 contrib/tools/png-fix-itxt.$(OBJEXT): contrib/tools/$(am__dirstamp) \
 	contrib/tools/$(DEPDIR)/$(am__dirstamp)

@ -1127,10 +1150,10 @@ pngfix$(EXEEXT): $(pngfix_OBJECTS) $(pngfix_DEPENDENCIES) $(EXTRA_pngfix_DEPENDE
 	$(AM_V_CCLD)$(LINK) $(pngfix_OBJECTS) $(pngfix_LDADD) $(LIBS)
 contrib/libtests/$(am__dirstamp):
 	@$(MKDIR_P) contrib/libtests
-	@: > contrib/libtests/$(am__dirstamp)
+	@: >>contrib/libtests/$(am__dirstamp)
 contrib/libtests/$(DEPDIR)/$(am__dirstamp):
 	@$(MKDIR_P) contrib/libtests/$(DEPDIR)
-	@: > contrib/libtests/$(DEPDIR)/$(am__dirstamp)
+	@: >>contrib/libtests/$(DEPDIR)/$(am__dirstamp)
 contrib/libtests/pngimage.$(OBJEXT): contrib/libtests/$(am__dirstamp) \
 	contrib/libtests/$(DEPDIR)/$(am__dirstamp)

@ -1216,6 +1239,8 @@ mostlyclean-compile:
 	-rm -f mips/*.lo
 	-rm -f powerpc/*.$(OBJEXT)
 	-rm -f powerpc/*.lo
+	-rm -f riscv/*.$(OBJEXT)
+	-rm -f riscv/*.lo

 distclean-compile:
 	-rm -f *.tab.c
@ -1237,7 +1262,6 @@ distclean-compile:
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pngwtran.Plo@am__quote@ # am--include-marker
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pngwutil.Plo@am__quote@ # am--include-marker
@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/$(DEPDIR)/pngimage.Po@am__quote@ # am--include-marker
@ -1257,37 +1281,15 @@ distclean-compile:
@AMDEP_TRUE@@am__include@ @am__quote@mips/$(DEPDIR)/mips_init.Plo@am__quote@ # am--include-marker
@AMDEP_TRUE@@am__include@ @am__quote@powerpc/$(DEPDIR)/filter_vsx_intrinsics.Plo@am__quote@ # am--include-marker
@AMDEP_TRUE@@am__include@ @am__quote@powerpc/$(DEPDIR)/powerpc_init.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.Plo@am__quote@ # am--include-marker

 $(am__depfiles_remade):
 	@$(MKDIR_P) $(@D)
-	@echo '# dummy' >$@-t && $(am__mv) $@-t $@
+	@: >>$@

 am--depfiles: $(am__depfiles_remade)

-.S.o:
-@am__fastdepCCAS_TRUE@	$(AM_V_CPPAS)depbase=`echo $@ | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.o$$||'`;\
-@am__fastdepCCAS_TRUE@	$(CPPASCOMPILE) -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ $< &&\
-@am__fastdepCCAS_TRUE@	$(am__mv) $$depbase.Tpo $$depbase.Po
-@AMDEP_TRUE@@am__fastdepCCAS_FALSE@	$(AM_V_CPPAS)source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
-@AMDEP_TRUE@@am__fastdepCCAS_FALSE@	DEPDIR=$(DEPDIR) $(CCASDEPMODE) $(depcomp) @AMDEPBACKSLASH@
-@am__fastdepCCAS_FALSE@	$(AM_V_CPPAS@am__nodep@)$(CPPASCOMPILE) -c -o $@ $<
-
-.S.obj:
-@am__fastdepCCAS_TRUE@	$(AM_V_CPPAS)depbase=`echo $@ | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.obj$$||'`;\
-@am__fastdepCCAS_TRUE@	$(CPPASCOMPILE) -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ `$(CYGPATH_W) '$<'` &&\
-@am__fastdepCCAS_TRUE@	$(am__mv) $$depbase.Tpo $$depbase.Po
-@AMDEP_TRUE@@am__fastdepCCAS_FALSE@	$(AM_V_CPPAS)source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
-@AMDEP_TRUE@@am__fastdepCCAS_FALSE@	DEPDIR=$(DEPDIR) $(CCASDEPMODE) $(depcomp) @AMDEPBACKSLASH@
-@am__fastdepCCAS_FALSE@	$(AM_V_CPPAS@am__nodep@)$(CPPASCOMPILE) -c -o $@ `$(CYGPATH_W) '$<'`
-
-.S.lo:
-@am__fastdepCCAS_TRUE@	$(AM_V_CPPAS)depbase=`echo $@ | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.lo$$||'`;\
-@am__fastdepCCAS_TRUE@	$(LTCPPASCOMPILE) -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ $< &&\
-@am__fastdepCCAS_TRUE@	$(am__mv) $$depbase.Tpo $$depbase.Plo
-@AMDEP_TRUE@@am__fastdepCCAS_FALSE@	$(AM_V_CPPAS)source='$<' object='$@' libtool=yes @AMDEPBACKSLASH@
-@AMDEP_TRUE@@am__fastdepCCAS_FALSE@	DEPDIR=$(DEPDIR) $(CCASDEPMODE) $(depcomp) @AMDEPBACKSLASH@
-@am__fastdepCCAS_FALSE@	$(AM_V_CPPAS@am__nodep@)$(LTCPPASCOMPILE) -c -o $@ $<
-
 .c.o:
@am__fastdepCC_TRUE@	$(AM_V_CC)depbase=`echo $@ | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.o$$||'`;\
@am__fastdepCC_TRUE@	$(COMPILE) -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ $< &&\
@ -1326,6 +1328,20 @@ loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo: loo
@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(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

+riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.lo: riscv/riscv_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@rvv_la_CFLAGS) $(CFLAGS) -MT riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.lo -MD -MP -MF riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.Tpo -c -o riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.lo `test -f 'riscv/riscv_init.c' || echo '$(srcdir)/'`riscv/riscv_init.c
+@am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.Tpo riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.Plo
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	$(AM_V_CC)source='riscv/riscv_init.c' object='riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.lo' libtool=yes @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(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@rvv_la_CFLAGS) $(CFLAGS) -c -o riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.lo `test -f 'riscv/riscv_init.c' || echo '$(srcdir)/'`riscv/riscv_init.c
+
+riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.lo: riscv/filter_rvv_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@rvv_la_CFLAGS) $(CFLAGS) -MT riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.lo -MD -MP -MF riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.Tpo -c -o riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.lo `test -f 'riscv/filter_rvv_intrinsics.c' || echo '$(srcdir)/'`riscv/filter_rvv_intrinsics.c
+@am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.Tpo riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.Plo
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	$(AM_V_CC)source='riscv/filter_rvv_intrinsics.c' object='riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.lo' libtool=yes @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(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@rvv_la_CFLAGS) $(CFLAGS) -c -o riscv/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.lo `test -f 'riscv/filter_rvv_intrinsics.c' || echo '$(srcdir)/'`riscv/filter_rvv_intrinsics.c
+
 mostlyclean-libtool:
 	-rm -f *.lo

@ -1336,6 +1352,7 @@ clean-libtool:
 	-rm -rf loongarch/.libs loongarch/_libs
 	-rm -rf mips/.libs mips/_libs
 	-rm -rf powerpc/.libs powerpc/_libs
+	-rm -rf riscv/.libs riscv/_libs

 distclean-libtool:
 	-rm -f libtool config.lt
@ -1561,7 +1578,6 @@ distclean-tags:
 am--fnord $(TEST_LOGS) $(TEST_LOGS:.log=.trs): $(am__force_recheck)
 am--force-recheck:
 	@:
-
 $(TEST_SUITE_LOG): $(TEST_LOGS)
 	@$(am__set_TESTS_bases); \
 	am__f_ok () { test -f "$$1" && test -r "$$1"; }; \
@ -1637,10 +1653,37 @@ $(TEST_SUITE_LOG): $(TEST_LOGS)
 	  result_count $$1 "XPASS:" $$xpass "$$red"; \
 	  result_count $$1 "ERROR:" $$error "$$mgn"; \
 	}; \
+	output_system_information () \
+	{ \
+          echo;                                     \
+	  { uname -a | $(AWK) '{                    \
+  printf "System information (uname -a):";          \
+  for (i = 1; i < NF; ++i)                          \
+    {                                               \
+      if (i != 2)                                   \
+        printf " %s", $$i;                          \
+    }                                               \
+  printf "\n";                                      \
+}'; } 2>&1;                                         \
+	  if test -r /etc/os-release; then          \
+	    echo "Distribution information (/etc/os-release):"; \
+	    sed 8q /etc/os-release;                 \
+	  elif test -r /etc/issue; then             \
+	    echo "Distribution information (/etc/issue):";      \
+	    cat /etc/issue;                         \
+	  fi;                                       \
+	}; \
+	please_report () \
+	{ \
+echo "Some test(s) failed.  Please report this to $(PACKAGE_BUGREPORT),";    \
+echo "together with the test-suite.log file (gzipped) and your system";      \
+echo "information.  Thanks.";                                                \
+	}; \
 	{								\
 	  echo "$(PACKAGE_STRING): $(subdir)/$(TEST_SUITE_LOG)" |	\
 	    $(am__rst_title);						\
 	  create_testsuite_report --no-color;				\
+	  output_system_information;                                    \
 	  echo;								\
 	  echo ".. contents:: :depth: 2";				\
 	  echo;								\
@ -1660,26 +1703,25 @@ $(TEST_SUITE_LOG): $(TEST_LOGS)
 	create_testsuite_report --maybe-color;				\
 	echo "$$col$$br$$std";						\
 	if $$success; then :; else					\
-	  echo "$${col}See $(subdir)/$(TEST_SUITE_LOG)$${std}";		\
+	  echo "$${col}See $(subdir)/$(TEST_SUITE_LOG) for debugging.$${std}";\
 	  if test -n "$(PACKAGE_BUGREPORT)"; then			\
-	    echo "$${col}Please report to $(PACKAGE_BUGREPORT)$${std}";	\
+	    please_report | sed -e "s/^/$${col}/" -e s/'$$'/"$${std}"/; \
 	  fi;								\
 	  echo "$$col$$br$$std";					\
 	fi;								\
 	$$success || exit 1

 check-TESTS: $(check_PROGRAMS)
-	@list='$(RECHECK_LOGS)';           test -z "$$list" || rm -f $$list
-	@list='$(RECHECK_LOGS:.log=.trs)'; test -z "$$list" || rm -f $$list
-	@test -z "$(TEST_SUITE_LOG)" || rm -f $(TEST_SUITE_LOG)
+	@$(am__rm_f) $(RECHECK_LOGS)
+	@$(am__rm_f) $(RECHECK_LOGS:.log=.trs)
+	@$(am__rm_f) $(TEST_SUITE_LOG)
 	@set +e; $(am__set_TESTS_bases); \
 	log_list=`for i in $$bases; do echo $$i.log; done`; \
-	trs_list=`for i in $$bases; do echo $$i.trs; done`; \
-	log_list=`echo $$log_list`; trs_list=`echo $$trs_list`; \
+	log_list=`echo $$log_list`; \
 	$(MAKE) $(AM_MAKEFLAGS) $(TEST_SUITE_LOG) TEST_LOGS="$$log_list"; \
 	exit $$?;
 recheck: all $(check_PROGRAMS)
-	@test -z "$(TEST_SUITE_LOG)" || rm -f $(TEST_SUITE_LOG)
+	@$(am__rm_f) $(TEST_SUITE_LOG)
 	@set +e; $(am__set_TESTS_bases); \
 	bases=`for i in $$bases; do echo $$i; done \
 	         | $(am__list_recheck_tests)` || exit 1; \
@ -1927,12 +1969,13 @@ tests/pngimage-full.log: tests/pngimage-full
@am__EXEEXT_TRUE@	--log-file $$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

 distdir-am: $(DISTFILES)
 	$(am__remove_distdir)
-	test -d "$(distdir)" || mkdir "$(distdir)"
+	$(AM_V_at)$(MKDIR_P) "$(distdir)"
 	@srcdirstrip=`echo "$(srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
 	topsrcdirstrip=`echo "$(top_srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
 	list='$(DISTFILES)'; \
@ -1980,6 +2023,10 @@ dist-bzip2: distdir
 	tardir=$(distdir) && $(am__tar) | BZIP2=$${BZIP2--9} bzip2 -c >$(distdir).tar.bz2
 	$(am__post_remove_distdir)

+dist-bzip3: distdir
+	tardir=$(distdir) && $(am__tar) | bzip3 -c >$(distdir).tar.bz3
+	$(am__post_remove_distdir)
+
 dist-lzip: distdir
 	tardir=$(distdir) && $(am__tar) | lzip -c $${LZIP_OPT--9} >$(distdir).tar.lz
 	$(am__post_remove_distdir)
@ -2020,9 +2067,11 @@ dist dist-all:
 distcheck: dist
 	case '$(DIST_ARCHIVES)' in \
 	*.tar.gz*) \
-	  eval GZIP= gzip $(GZIP_ENV) -dc $(distdir).tar.gz | $(am__untar) ;;\
+	  eval GZIP= gzip -dc $(distdir).tar.gz | $(am__untar) ;;\
 	*.tar.bz2*) \
 	  bzip2 -dc $(distdir).tar.bz2 | $(am__untar) ;;\
+	*.tar.bz3*) \
+	  bzip3 -dc $(distdir).tar.bz3 | $(am__untar) ;;\
 	*.tar.lz*) \
 	  lzip -dc $(distdir).tar.lz | $(am__untar) ;;\
 	*.tar.xz*) \
@ -2030,7 +2079,7 @@ distcheck: dist
 	*.tar.Z*) \
 	  uncompress -c $(distdir).tar.Z | $(am__untar) ;;\
 	*.shar.gz*) \
-	  eval GZIP= gzip $(GZIP_ENV) -dc $(distdir).shar.gz | unshar ;;\
+	  eval GZIP= gzip -dc $(distdir).shar.gz | unshar ;;\
 	*.zip*) \
 	  unzip $(distdir).zip ;;\
 	*.tar.zst*) \
@ -2138,36 +2187,38 @@ install-strip:
 	    "INSTALL_PROGRAM_ENV=STRIPPROG='$(STRIP)'" install; \
 	fi
 mostlyclean-generic:
-	-test -z "$(TEST_LOGS)" || rm -f $(TEST_LOGS)
-	-test -z "$(TEST_LOGS:.log=.trs)" || rm -f $(TEST_LOGS:.log=.trs)
-	-test -z "$(TEST_SUITE_LOG)" || rm -f $(TEST_SUITE_LOG)
+	-$(am__rm_f) $(TEST_LOGS)
+	-$(am__rm_f) $(TEST_LOGS:.log=.trs)
+	-$(am__rm_f) $(TEST_SUITE_LOG)

 clean-generic:
-	-test -z "$(CLEANFILES)" || rm -f $(CLEANFILES)
+	-$(am__rm_f) $(CLEANFILES)

 distclean-generic:
-	-test -z "$(CONFIG_CLEAN_FILES)" || rm -f $(CONFIG_CLEAN_FILES)
-	-test . = "$(srcdir)" || test -z "$(CONFIG_CLEAN_VPATH_FILES)" || rm -f $(CONFIG_CLEAN_VPATH_FILES)
-	-rm -f arm/$(DEPDIR)/$(am__dirstamp)
-	-rm -f arm/$(am__dirstamp)
-	-rm -f contrib/libtests/$(DEPDIR)/$(am__dirstamp)
-	-rm -f contrib/libtests/$(am__dirstamp)
-	-rm -f contrib/tools/$(DEPDIR)/$(am__dirstamp)
-	-rm -f contrib/tools/$(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)/$(am__dirstamp)
-	-rm -f powerpc/$(am__dirstamp)
+	-$(am__rm_f) $(CONFIG_CLEAN_FILES)
+	-test . = "$(srcdir)" || $(am__rm_f) $(CONFIG_CLEAN_VPATH_FILES)
+	-$(am__rm_f) arm/$(DEPDIR)/$(am__dirstamp)
+	-$(am__rm_f) arm/$(am__dirstamp)
+	-$(am__rm_f) contrib/libtests/$(DEPDIR)/$(am__dirstamp)
+	-$(am__rm_f) contrib/libtests/$(am__dirstamp)
+	-$(am__rm_f) contrib/tools/$(DEPDIR)/$(am__dirstamp)
+	-$(am__rm_f) contrib/tools/$(am__dirstamp)
+	-$(am__rm_f) intel/$(DEPDIR)/$(am__dirstamp)
+	-$(am__rm_f) intel/$(am__dirstamp)
+	-$(am__rm_f) loongarch/$(DEPDIR)/$(am__dirstamp)
+	-$(am__rm_f) loongarch/$(am__dirstamp)
+	-$(am__rm_f) mips/$(DEPDIR)/$(am__dirstamp)
+	-$(am__rm_f) mips/$(am__dirstamp)
+	-$(am__rm_f) powerpc/$(DEPDIR)/$(am__dirstamp)
+	-$(am__rm_f) powerpc/$(am__dirstamp)
+	-$(am__rm_f) riscv/$(DEPDIR)/$(am__dirstamp)
+	-$(am__rm_f) riscv/$(am__dirstamp)

 maintainer-clean-generic:
 	@echo "This command is intended for maintainers to use"
 	@echo "it deletes files that may require special tools to rebuild."
-	-test -z "$(BUILT_SOURCES)" || rm -f $(BUILT_SOURCES)
-	-test -z "$(MAINTAINERCLEANFILES)" || rm -f $(MAINTAINERCLEANFILES)
+	-$(am__rm_f) $(BUILT_SOURCES)
+	-$(am__rm_f) $(MAINTAINERCLEANFILES)
@DO_INSTALL_LIBPNG_CONFIG_FALSE@@DO_INSTALL_LINKS_FALSE@install-exec-hook:
@DO_INSTALL_LIBPNG_PC_FALSE@@DO_INSTALL_LINKS_FALSE@install-data-hook:
@DO_INSTALL_LIBPNG_CONFIG_FALSE@@DO_INSTALL_LIBPNG_PC_FALSE@@DO_INSTALL_LINKS_FALSE@uninstall-hook:
@ -2179,7 +2230,7 @@ clean-am: clean-binPROGRAMS clean-checkPROGRAMS clean-generic \

 distclean: distclean-am
 	-rm -f $(am__CONFIG_DISTCLEAN_FILES)
-		-rm -f ./$(DEPDIR)/png.Plo
+	-rm -f ./$(DEPDIR)/png.Plo
 	-rm -f ./$(DEPDIR)/pngerror.Plo
 	-rm -f ./$(DEPDIR)/pngget.Plo
 	-rm -f ./$(DEPDIR)/pngmem.Plo
@ -2196,7 +2247,6 @@ distclean: distclean-am
 	-rm -f ./$(DEPDIR)/pngwtran.Plo
 	-rm -f ./$(DEPDIR)/pngwutil.Plo
 	-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/$(DEPDIR)/pngimage.Po
@ -2216,6 +2266,8 @@ distclean: distclean-am
 	-rm -f mips/$(DEPDIR)/mips_init.Plo
 	-rm -f powerpc/$(DEPDIR)/filter_vsx_intrinsics.Plo
 	-rm -f powerpc/$(DEPDIR)/powerpc_init.Plo
+	-rm -f riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.Plo
+	-rm -f riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.Plo
 	-rm -f Makefile
 distclean-am: clean-am distclean-compile distclean-generic \
 	distclean-hdr distclean-libtool distclean-tags
@ -2267,7 +2319,7 @@ installcheck-am:
 maintainer-clean: maintainer-clean-am
 	-rm -f $(am__CONFIG_DISTCLEAN_FILES)
 	-rm -rf $(top_srcdir)/autom4te.cache
-		-rm -f ./$(DEPDIR)/png.Plo
+	-rm -f ./$(DEPDIR)/png.Plo
 	-rm -f ./$(DEPDIR)/pngerror.Plo
 	-rm -f ./$(DEPDIR)/pngget.Plo
 	-rm -f ./$(DEPDIR)/pngmem.Plo
@ -2284,7 +2336,6 @@ maintainer-clean: maintainer-clean-am
 	-rm -f ./$(DEPDIR)/pngwtran.Plo
 	-rm -f ./$(DEPDIR)/pngwutil.Plo
 	-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/$(DEPDIR)/pngimage.Po
@ -2304,6 +2355,8 @@ maintainer-clean: maintainer-clean-am
 	-rm -f mips/$(DEPDIR)/mips_init.Plo
 	-rm -f powerpc/$(DEPDIR)/filter_vsx_intrinsics.Plo
 	-rm -f powerpc/$(DEPDIR)/powerpc_init.Plo
+	-rm -f riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-filter_rvv_intrinsics.Plo
+	-rm -f riscv/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.Plo
 	-rm -f Makefile
 maintainer-clean-am: distclean-am maintainer-clean-generic

@ -2336,15 +2389,15 @@ uninstall-man: uninstall-man3 uninstall-man5
 	clean-checkPROGRAMS clean-cscope clean-generic \
 	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 \
+	dist-bzip3 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 \
@ -2548,3 +2601,10 @@ all-am: $(check_PROGRAMS)
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.
 .NOEXPORT:
+
+# Tell GNU make to disable its built-in pattern rules.
+%:: %,v
+%:: RCS/%,v
+%:: RCS/%
+%:: s.%
+%:: SCCS/s.%
--- a/8
+++ b/8
@ -1,5 +1,5 @@
-README for libpng version 1.6.43
-================================
+README for libpng version 1.6.51.git
+====================================

 See the note about version numbers near the top of `png.h`.
 See `INSTALL` for instructions on how to install libpng.
@ -147,6 +147,7 @@ Files included in this distribution
    loongarch/    =>  Optimized code for LoongArch LSX
    mips/         =>  Optimized code for MIPS MSA and MIPS MMI
    powerpc/      =>  Optimized code for PowerPC VSX
+    riscv/        =>  Optimized code for the RISC-V platform
    ci/           =>  Scripts for continuous integration
    contrib/      =>  External contributions
        arm-neon/     =>  Optimized code for the ARM-NEON platform
@ -157,13 +158,12 @@ Files included in this distribution
                          "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
        pngexif/      =>  Program to inspect the EXIF information in PNG files
        pngminim/     =>  Minimal decoder, encoder, and progressive decoder
                          programs demonstrating the use of pngusr.dfa
        pngminus/     =>  Simple pnm2png and png2pnm programs
        pngsuite/     =>  Test images
+        riscv-rvv/    =>  Optimized code for the RISC-V Vector platform
        testpngs/     =>  Test images
        tools/        =>  Various tools
        visupng/      =>  VisualPng, a Windows viewer for PNG images
--- a/43
+++ b/43
@ -1,23 +1,22 @@
-TODO - list of things to do for libpng:
+TODO list for libpng
+--------------------

-* 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.
+ * Fix all defects (duh!)
+ * 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 to 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.
--- a/aclocal.m4
+++ b/aclocal.m4
@ -1,6 +1,6 @@
-# generated automatically by aclocal 1.16.5 -*- Autoconf -*-
+# generated automatically by aclocal 1.18.1 -*- Autoconf -*-

-# Copyright (C) 1996-2021 Free Software Foundation, Inc.
+# Copyright (C) 1996-2025 Free Software Foundation, Inc.

 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -20,7 +20,7 @@ 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) 2002-2021 Free Software Foundation, Inc.
+# Copyright (C) 2002-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -32,10 +32,10 @@ To do so, use the procedure documented by the package, typically 'autoreconf'.])
 # generated from the m4 files accompanying Automake X.Y.
 # (This private macro should not be called outside this file.)
 AC_DEFUN([AM_AUTOMAKE_VERSION],
-[am__api_version='1.16'
+[am__api_version='1.18'
 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], [1.16.5], [],
+m4_if([$1], [1.18.1], [],
      [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([1.16.5])dnl
+[AM_AUTOMAKE_VERSION([1.18.1])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) 2001-2021 Free Software Foundation, Inc.
+# Copyright (C) 2001-2025 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) 2001-2021 Free Software Foundation, Inc.
+# Copyright (C) 2001-2025 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) 1997-2021 Free Software Foundation, Inc.
+# Copyright (C) 1997-2025 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) 1999-2021 Free Software Foundation, Inc.
+# Copyright (C) 1999-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -293,7 +293,7 @@ AC_CACHE_CHECK([dependency style of $depcc],
      # icc doesn't choke on unknown options, it will just issue warnings
      # or remarks (even with -Werror).  So we grep stderr for any message
      # that says an option was ignored or not supported.
-      # When given -MP, icc 7.0 and 7.1 complain thusly:
+      # When given -MP, icc 7.0 and 7.1 complain thus:
      #   icc: Command line warning: ignoring option '-M'; no argument required
      # The diagnosis changed in icc 8.0:
      #   icc: Command line remark: option '-MP' not supported
@ -352,7 +352,7 @@ _AM_SUBST_NOTMAKE([am__nodep])dnl

 # Generate code to set up dependency tracking.              -*- Autoconf -*-

-# Copyright (C) 1999-2021 Free Software Foundation, Inc.
+# Copyright (C) 1999-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -420,7 +420,7 @@ AC_DEFUN([AM_OUTPUT_DEPENDENCY_COMMANDS],

 # Do all the work for Automake.                             -*- Autoconf -*-

-# Copyright (C) 1996-2021 Free Software Foundation, Inc.
+# Copyright (C) 1996-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -520,8 +520,9 @@ AC_REQUIRE([AC_PROG_AWK])dnl
 AC_REQUIRE([AC_PROG_MAKE_SET])dnl
 AC_REQUIRE([AM_SET_LEADING_DOT])dnl
 _AM_IF_OPTION([tar-ustar], [_AM_PROG_TAR([ustar])],
-	      [_AM_IF_OPTION([tar-pax], [_AM_PROG_TAR([pax])],
-			     [_AM_PROG_TAR([v7])])])
+  [_AM_IF_OPTION([tar-pax], [_AM_PROG_TAR([pax])],
+    [_AM_IF_OPTION([tar-v7], [_AM_PROG_TAR([v7])],
+      [_AM_PROG_TAR([ustar])])])])
 _AM_IF_OPTION([no-dependencies],,
 [AC_PROVIDE_IFELSE([AC_PROG_CC],
 		  [_AM_DEPENDENCIES([CC])],
@ -554,7 +555,7 @@ if test -z "$CSCOPE"; then
 fi
 AC_SUBST([CSCOPE])

-AC_REQUIRE([AM_SILENT_RULES])dnl
+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
 dnl macro is hooked onto _AC_COMPILER_EXEEXT early, see below.
@ -562,47 +563,9 @@ AC_CONFIG_COMMANDS_PRE(dnl
 [m4_provide_if([_AM_COMPILER_EXEEXT],
  [AM_CONDITIONAL([am__EXEEXT], [test -n "$EXEEXT"])])])dnl

-# POSIX will say in a future version that running "rm -f" with no argument
-# is OK; and we want to be able to make that assumption in our Makefile
-# recipes.  So use an aggressive probe to check that the usage we want is
-# actually supported "in the wild" to an acceptable degree.
-# See automake bug#10828.
-# To make any issue more visible, cause the running configure to be aborted
-# by default if the 'rm' program in use doesn't match our expectations; the
-# user can still override this though.
-if rm -f && rm -fr && rm -rf; then : OK; else
-  cat >&2 <<'END'
-Oops!
+AC_REQUIRE([_AM_PROG_RM_F])
+AC_REQUIRE([_AM_PROG_XARGS_N])

-Your 'rm' program seems unable to run without file operands specified
-on the command line, even when the '-f' option is present.  This is contrary
-to the behaviour of most rm programs out there, and not conforming with
-the upcoming POSIX standard: <http://austingroupbugs.net/view.php?id=542>
-
-Please tell bug-automake@gnu.org about your system, including the value
-of your $PATH and any error possibly output before this message.  This
-can help us improve future automake versions.
-
-END
-  if test x"$ACCEPT_INFERIOR_RM_PROGRAM" = x"yes"; then
-    echo 'Configuration will proceed anyway, since you have set the' >&2
-    echo 'ACCEPT_INFERIOR_RM_PROGRAM variable to "yes"' >&2
-    echo >&2
-  else
-    cat >&2 <<'END'
-Aborting the configuration process, to ensure you take notice of the issue.
-
-You can download and install GNU coreutils to get an 'rm' implementation
-that behaves properly: <https://www.gnu.org/software/coreutils/>.
-
-If you want to complete the configuration process using your problematic
-'rm' anyway, export the environment variable ACCEPT_INFERIOR_RM_PROGRAM
-to "yes", and re-run configure.
-
-END
-    AC_MSG_ERROR([Your 'rm' program is bad, sorry.])
-  fi
-fi
 dnl The trailing newline in this macro's definition is deliberate, for
 dnl backward compatibility and to allow trailing 'dnl'-style comments
 dnl after the AM_INIT_AUTOMAKE invocation. See automake bug#16841.
@ -635,7 +598,7 @@ for _am_header in $config_headers :; do
 done
 echo "timestamp for $_am_arg" >`AS_DIRNAME(["$_am_arg"])`/stamp-h[]$_am_stamp_count])

-# Copyright (C) 2001-2021 Free Software Foundation, Inc.
+# Copyright (C) 2001-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -656,7 +619,7 @@ if test x"${install_sh+set}" != xset; then
 fi
 AC_SUBST([install_sh])])

-# Copyright (C) 2003-2021 Free Software Foundation, Inc.
+# Copyright (C) 2003-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -678,7 +641,7 @@ AC_SUBST([am__leading_dot])])
 # Add --enable-maintainer-mode option to configure.         -*- Autoconf -*-
 # From Jim Meyering

-# Copyright (C) 1996-2021 Free Software Foundation, Inc.
+# Copyright (C) 1996-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -713,7 +676,7 @@ AC_MSG_CHECKING([whether to enable maintainer-specific portions of Makefiles])

 # Check to see how 'make' treats includes.	            -*- Autoconf -*-

-# Copyright (C) 2001-2021 Free Software Foundation, Inc.
+# Copyright (C) 2001-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -756,7 +719,7 @@ AC_SUBST([am__quote])])

 # Fake the existence of programs that GNU maintainers use.  -*- Autoconf -*-

-# Copyright (C) 1997-2021 Free Software Foundation, Inc.
+# Copyright (C) 1997-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -790,7 +753,7 @@ fi

 # Helper functions for option handling.                     -*- Autoconf -*-

-# Copyright (C) 2001-2021 Free Software Foundation, Inc.
+# Copyright (C) 2001-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -819,7 +782,7 @@ AC_DEFUN([_AM_SET_OPTIONS],
 AC_DEFUN([_AM_IF_OPTION],
 [m4_ifset(_AM_MANGLE_OPTION([$1]), [$2], [$3])])

-# Copyright (C) 1999-2021 Free Software Foundation, Inc.
+# Copyright (C) 1999-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -851,7 +814,10 @@ AC_CACHE_CHECK(
      break
    fi
  done
-  rm -f core conftest*
+  # aligned with autoconf, so not including core; see bug#72225.
+  rm -f -r a.out a.exe b.out conftest.$ac_ext conftest.$ac_objext \
+    conftest.dSYM conftest1.$ac_ext conftest1.$ac_objext conftest1.dSYM \
+    conftest2.$ac_ext conftest2.$ac_objext conftest2.dSYM
  unset am_i])
 if test "$am_cv_prog_cc_c_o" != yes; then
   # Losing compiler, so override with the script.
@ -866,7 +832,23 @@ AC_LANG_POP([C])])
 # For backward compatibility.
 AC_DEFUN_ONCE([AM_PROG_CC_C_O], [AC_REQUIRE([AC_PROG_CC])])

-# Copyright (C) 2001-2021 Free Software Foundation, Inc.
+# Copyright (C) 2022-2025 Free Software Foundation, Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# _AM_PROG_RM_F
+# ---------------
+# Check whether 'rm -f' without any arguments works.
+# https://bugs.gnu.org/10828
+AC_DEFUN([_AM_PROG_RM_F],
+[am__rm_f_notfound=
+AS_IF([(rm -f && rm -fr && rm -rf) 2>/dev/null], [], [am__rm_f_notfound='""'])
+AC_SUBST(am__rm_f_notfound)
+])
+
+# Copyright (C) 2001-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -885,26 +867,181 @@ AC_DEFUN([AM_RUN_LOG],

 # Check to make sure that the build environment is sane.    -*- Autoconf -*-

-# Copyright (C) 1996-2021 Free Software Foundation, Inc.
+# Copyright (C) 1996-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.

+# _AM_SLEEP_FRACTIONAL_SECONDS
+# ----------------------------
+AC_DEFUN([_AM_SLEEP_FRACTIONAL_SECONDS], [dnl
+AC_CACHE_CHECK([whether sleep supports fractional seconds],
+               am_cv_sleep_fractional_seconds, [dnl
+AS_IF([sleep 0.001 2>/dev/null], [am_cv_sleep_fractional_seconds=yes],
+                                 [am_cv_sleep_fractional_seconds=no])
+])])
+
+# _AM_FILESYSTEM_TIMESTAMP_RESOLUTION
+# -----------------------------------
+# Determine the filesystem's resolution for file modification
+# timestamps.  The coarsest we know of is FAT, with a resolution
+# of only two seconds, even with the most recent "exFAT" extensions.
+# The finest (e.g. ext4 with large inodes, XFS, ZFS) is one
+# nanosecond, matching clock_gettime.  However, it is probably not
+# possible to delay execution of a shell script for less than one
+# millisecond, due to process creation overhead and scheduling
+# granularity, so we don't check for anything finer than that. (See below.)
+AC_DEFUN([_AM_FILESYSTEM_TIMESTAMP_RESOLUTION], [dnl
+AC_REQUIRE([_AM_SLEEP_FRACTIONAL_SECONDS])
+AC_CACHE_CHECK([filesystem timestamp resolution],
+               am_cv_filesystem_timestamp_resolution, [dnl
+# Default to the worst case.
+am_cv_filesystem_timestamp_resolution=2
+
+# Only try to go finer than 1 sec if sleep can do it.
+# Don't try 1 sec, because if 0.01 sec and 0.1 sec don't work,
+# - 1 sec is not much of a win compared to 2 sec, and
+# - it takes 2 seconds to perform the test whether 1 sec works.
+# 
+# Instead, just use the default 2s on platforms that have 1s resolution,
+# accept the extra 1s delay when using $sleep in the Automake tests, in
+# exchange for not incurring the 2s delay for running the test for all
+# packages.
+#
+am_try_resolutions=
+if test "$am_cv_sleep_fractional_seconds" = yes; then
+  # Even a millisecond often causes a bunch of false positives,
+  # so just try a hundredth of a second. The time saved between .001 and
+  # .01 is not terribly consequential.
+  am_try_resolutions="0.01 0.1 $am_try_resolutions"
+fi
+
+# In order to catch current-generation FAT out, we must *modify* files
+# that already exist; the *creation* timestamp is finer.  Use names
+# that make ls -t sort them differently when they have equal
+# timestamps than when they have distinct timestamps, keeping
+# in mind that ls -t prints the *newest* file first.
+rm -f conftest.ts?
+: > conftest.ts1
+: > conftest.ts2
+: > conftest.ts3
+
+# Make sure ls -t actually works.  Do 'set' in a subshell so we don't
+# clobber the current shell's arguments. (Outer-level square brackets
+# are removed by m4; they're present so that m4 does not expand
+# <dollar><star>; be careful, easy to get confused.)
+if (
+     set X `[ls -t conftest.ts[12]]` &&
+     {
+       test "$[]*" != "X conftest.ts1 conftest.ts2" ||
+       test "$[]*" != "X conftest.ts2 conftest.ts1";
+     }
+); then :; else
+  # If neither matched, then we have a broken ls.  This can happen
+  # if, for instance, CONFIG_SHELL is bash and it inherits a
+  # broken ls alias from the environment.  This has actually
+  # happened.  Such a system could not be considered "sane".
+  _AS_ECHO_UNQUOTED(
+    ["Bad output from ls -t: \"`[ls -t conftest.ts[12]]`\""],
+    [AS_MESSAGE_LOG_FD])
+  AC_MSG_FAILURE([ls -t produces unexpected output.
+Make sure there is not a broken ls alias in your environment.])
+fi
+
+for am_try_res in $am_try_resolutions; do
+  # Any one fine-grained sleep might happen to cross the boundary
+  # between two values of a coarser actual resolution, but if we do
+  # two fine-grained sleeps in a row, at least one of them will fall
+  # entirely within a coarse interval.
+  echo alpha > conftest.ts1
+  sleep $am_try_res
+  echo beta > conftest.ts2
+  sleep $am_try_res
+  echo gamma > conftest.ts3
+
+  # We assume that 'ls -t' will make use of high-resolution
+  # timestamps if the operating system supports them at all.
+  if (set X `ls -t conftest.ts?` &&
+      test "$[]2" = conftest.ts3 &&
+      test "$[]3" = conftest.ts2 &&
+      test "$[]4" = conftest.ts1); then
+    #
+    # Ok, ls -t worked. If we're at a resolution of 1 second, we're done,
+    # because we don't need to test make.
+    make_ok=true
+    if test $am_try_res != 1; then
+      # But if we've succeeded so far with a subsecond resolution, we
+      # have one more thing to check: make. It can happen that
+      # everything else supports the subsecond mtimes, but make doesn't;
+      # notably on macOS, which ships make 3.81 from 2006 (the last one
+      # released under GPLv2). https://bugs.gnu.org/68808
+      # 
+      # We test $MAKE if it is defined in the environment, else "make".
+      # It might get overridden later, but our hope is that in practice
+      # it does not matter: it is the system "make" which is (by far)
+      # the most likely to be broken, whereas if the user overrides it,
+      # probably they did so with a better, or at least not worse, make.
+      # https://lists.gnu.org/archive/html/automake/2024-06/msg00051.html
+      #
+      # Create a Makefile (real tab character here):
+      rm -f conftest.mk
+      echo 'conftest.ts1: conftest.ts2' >conftest.mk
+      echo '	touch conftest.ts2' >>conftest.mk
+      #
+      # Now, running
+      #   touch conftest.ts1; touch conftest.ts2; make
+      # should touch ts1 because ts2 is newer. This could happen by luck,
+      # but most often, it will fail if make's support is insufficient. So
+      # test for several consecutive successes.
+      #
+      # (We reuse conftest.ts[12] because we still want to modify existing
+      # files, not create new ones, per above.)
+      n=0
+      make=${MAKE-make}
+      until test $n -eq 3; do
+        echo one > conftest.ts1
+        sleep $am_try_res
+        echo two > conftest.ts2 # ts2 should now be newer than ts1
+        if $make -f conftest.mk | grep 'up to date' >/dev/null; then
+          make_ok=false
+          break # out of $n loop
+        fi
+        n=`expr $n + 1`
+      done
+    fi
+    #
+    if $make_ok; then
+      # Everything we know to check worked out, so call this resolution good.
+      am_cv_filesystem_timestamp_resolution=$am_try_res
+      break # out of $am_try_res loop
+    fi
+    # Otherwise, we'll go on to check the next resolution.
+  fi
+done
+rm -f conftest.ts?
+# (end _am_filesystem_timestamp_resolution)
+])])
+
 # AM_SANITY_CHECK
 # ---------------
 AC_DEFUN([AM_SANITY_CHECK],
-[AC_MSG_CHECKING([whether build environment is sane])
+[AC_REQUIRE([_AM_FILESYSTEM_TIMESTAMP_RESOLUTION])
+# This check should not be cached, as it may vary across builds of
+# different projects.
+AC_MSG_CHECKING([whether build environment is sane])
 # Reject unsafe characters in $srcdir or the absolute working directory
 # name.  Accept space and tab only in the latter.
 am_lf='
 '
 case `pwd` in
  *[[\\\"\#\$\&\'\`$am_lf]]*)
+    AC_MSG_RESULT([no])
    AC_MSG_ERROR([unsafe absolute working directory name]);;
 esac
 case $srcdir in
  *[[\\\"\#\$\&\'\`$am_lf\ \	]]*)
+    AC_MSG_RESULT([no])
    AC_MSG_ERROR([unsafe srcdir value: '$srcdir']);;
 esac

@ -913,49 +1050,40 @@ esac
 # symlink; some systems play weird games with the mod time of symlinks
 # (eg FreeBSD returns the mod time of the symlink's containing
 # directory).
-if (
-   am_has_slept=no
-   for am_try in 1 2; do
-     echo "timestamp, slept: $am_has_slept" > conftest.file
-     set X `ls -Lt "$srcdir/configure" conftest.file 2> /dev/null`
-     if test "$[*]" = "X"; then
-	# -L didn't work.
-	set X `ls -t "$srcdir/configure" conftest.file`
-     fi
-     if test "$[*]" != "X $srcdir/configure conftest.file" \
-	&& test "$[*]" != "X conftest.file $srcdir/configure"; then
+am_build_env_is_sane=no
+am_has_slept=no
+rm -f conftest.file
+for am_try in 1 2; do
+  echo "timestamp, slept: $am_has_slept" > conftest.file
+  if (
+    set X `ls -Lt "$srcdir/configure" conftest.file 2> /dev/null`
+    if test "$[]*" = "X"; then
+      # -L didn't work.
+      set X `ls -t "$srcdir/configure" conftest.file`
+    fi
+    test "$[]2" = conftest.file
+  ); then
+    am_build_env_is_sane=yes
+    break
+  fi
+  # Just in case.
+  sleep "$am_cv_filesystem_timestamp_resolution"
+  am_has_slept=yes
+done

-	# If neither matched, then we have a broken ls.  This can happen
-	# if, for instance, CONFIG_SHELL is bash and it inherits a
-	# broken ls alias from the environment.  This has actually
-	# happened.  Such a system could not be considered "sane".
-	AC_MSG_ERROR([ls -t appears to fail.  Make sure there is not a broken
-  alias in your environment])
-     fi
-     if test "$[2]" = conftest.file || test $am_try -eq 2; then
-       break
-     fi
-     # Just in case.
-     sleep 1
-     am_has_slept=yes
-   done
-   test "$[2]" = conftest.file
-   )
-then
-   # Ok.
-   :
-else
-   AC_MSG_ERROR([newly created file is older than distributed files!
+AC_MSG_RESULT([$am_build_env_is_sane])
+if test "$am_build_env_is_sane" = no; then
+  AC_MSG_ERROR([newly created file is older than distributed files!
 Check your system clock])
 fi
-AC_MSG_RESULT([yes])
+
 # If we didn't sleep, we still need to ensure time stamps of config.status and
 # generated files are strictly newer.
 am_sleep_pid=
-if grep 'slept: no' conftest.file >/dev/null 2>&1; then
-  ( sleep 1 ) &
+AS_IF([test -e conftest.file || grep 'slept: no' conftest.file >/dev/null 2>&1],, [dnl
+  ( sleep "$am_cv_filesystem_timestamp_resolution" ) &
  am_sleep_pid=$!
-fi
+])
 AC_CONFIG_COMMANDS_PRE(
  [AC_MSG_CHECKING([that generated files are newer than configure])
   if test -n "$am_sleep_pid"; then
@ -966,18 +1094,18 @@ AC_CONFIG_COMMANDS_PRE(
 rm -f conftest.file
 ])

-# Copyright (C) 2009-2021 Free Software Foundation, Inc.
+# Copyright (C) 2009-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.

-# AM_SILENT_RULES([DEFAULT])
-# --------------------------
-# Enable less verbose build rules; with the default set to DEFAULT
-# ("yes" being less verbose, "no" or empty being verbose).
-AC_DEFUN([AM_SILENT_RULES],
-[AC_ARG_ENABLE([silent-rules], [dnl
+# _AM_SILENT_RULES
+# ----------------
+# Enable less verbose build rules support.
+AC_DEFUN([_AM_SILENT_RULES],
+[AM_DEFAULT_VERBOSITY=1
+AC_ARG_ENABLE([silent-rules], [dnl
 AS_HELP_STRING(
  [--enable-silent-rules],
  [less verbose build output (undo: "make V=1")])
@ -985,11 +1113,6 @@ AS_HELP_STRING(
  [--disable-silent-rules],
  [verbose build output (undo: "make V=0")])dnl
 ])
-case $enable_silent_rules in @%:@ (((
-  yes) AM_DEFAULT_VERBOSITY=0;;
-   no) AM_DEFAULT_VERBOSITY=1;;
-    *) AM_DEFAULT_VERBOSITY=m4_if([$1], [yes], [0], [1]);;
-esac
 dnl
 dnl A few 'make' implementations (e.g., NonStop OS and NextStep)
 dnl do not support nested variable expansions.
@ -1008,14 +1131,6 @@ am__doit:
 else
  am_cv_make_support_nested_variables=no
 fi])
-if test $am_cv_make_support_nested_variables = yes; then
-  dnl Using '$V' instead of '$(V)' breaks IRIX make.
-  AM_V='$(V)'
-  AM_DEFAULT_V='$(AM_DEFAULT_VERBOSITY)'
-else
-  AM_V=$AM_DEFAULT_VERBOSITY
-  AM_DEFAULT_V=$AM_DEFAULT_VERBOSITY
-fi
 AC_SUBST([AM_V])dnl
 AM_SUBST_NOTMAKE([AM_V])dnl
 AC_SUBST([AM_DEFAULT_V])dnl
@ -1024,9 +1139,37 @@ AC_SUBST([AM_DEFAULT_VERBOSITY])dnl
 AM_BACKSLASH='\'
 AC_SUBST([AM_BACKSLASH])dnl
 _AM_SUBST_NOTMAKE([AM_BACKSLASH])dnl
+dnl Delay evaluation of AM_DEFAULT_VERBOSITY to the end to allow multiple calls
+dnl to AM_SILENT_RULES to change the default value.
+AC_CONFIG_COMMANDS_PRE([dnl
+case $enable_silent_rules in @%:@ (((
+  yes) AM_DEFAULT_VERBOSITY=0;;
+   no) AM_DEFAULT_VERBOSITY=1;;
+esac
+if test $am_cv_make_support_nested_variables = yes; then
+  dnl Using '$V' instead of '$(V)' breaks IRIX make.
+  AM_V='$(V)'
+  AM_DEFAULT_V='$(AM_DEFAULT_VERBOSITY)'
+else
+  AM_V=$AM_DEFAULT_VERBOSITY
+  AM_DEFAULT_V=$AM_DEFAULT_VERBOSITY
+fi
+])dnl
 ])

-# Copyright (C) 2001-2021 Free Software Foundation, Inc.
+# AM_SILENT_RULES([DEFAULT])
+# --------------------------
+# Set the default verbosity level to DEFAULT ("yes" being less verbose, "no" or
+# empty being verbose).
+AC_DEFUN([AM_SILENT_RULES],
+[AC_REQUIRE([_AM_SILENT_RULES])
+AM_DEFAULT_VERBOSITY=m4_if([$1], [yes], [0], [1])m4_newline
+dnl We intentionally force a newline after the assignment, since a) nothing
+dnl good can come of more text following, and b) that was the behavior
+dnl before 1.17. See https://bugs.gnu.org/72267.
+])
+
+# Copyright (C) 2001-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -1054,7 +1197,7 @@ fi
 INSTALL_STRIP_PROGRAM="\$(install_sh) -c -s"
 AC_SUBST([INSTALL_STRIP_PROGRAM])])

-# Copyright (C) 2006-2021 Free Software Foundation, Inc.
+# Copyright (C) 2006-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -1073,7 +1216,7 @@ AC_DEFUN([AM_SUBST_NOTMAKE], [_AM_SUBST_NOTMAKE($@)])

 # Check how to create a tarball.                            -*- Autoconf -*-

-# Copyright (C) 2004-2021 Free Software Foundation, Inc.
+# Copyright (C) 2004-2025 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -1119,15 +1262,19 @@ m4_if([$1], [v7],
      am_uid=`id -u || echo unknown`
      am_gid=`id -g || echo unknown`
      AC_MSG_CHECKING([whether UID '$am_uid' is supported by ustar format])
-      if test $am_uid -le $am_max_uid; then
-         AC_MSG_RESULT([yes])
+      if test x$am_uid = xunknown; then
+        AC_MSG_WARN([ancient id detected; assuming current UID is ok, but dist-ustar might not work])
+      elif test $am_uid -le $am_max_uid; then
+        AC_MSG_RESULT([yes])
      else
-         AC_MSG_RESULT([no])
-         _am_tools=none
+        AC_MSG_RESULT([no])
+        _am_tools=none
      fi
      AC_MSG_CHECKING([whether GID '$am_gid' is supported by ustar format])
-      if test $am_gid -le $am_max_gid; then
-         AC_MSG_RESULT([yes])
+      if test x$gm_gid = xunknown; then
+        AC_MSG_WARN([ancient id detected; assuming current GID is ok, but dist-ustar might not work])
+      elif test $am_gid -le $am_max_gid; then
+        AC_MSG_RESULT([yes])
      else
        AC_MSG_RESULT([no])
        _am_tools=none
@ -1204,6 +1351,26 @@ AC_SUBST([am__tar])
 AC_SUBST([am__untar])
 ]) # _AM_PROG_TAR

+# Copyright (C) 2022-2025 Free Software Foundation, Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# _AM_PROG_XARGS_N
+# ----------------
+# Check whether 'xargs -n' works.  It should work everywhere, so the fallback
+# is not optimized at all as we never expect to use it.
+AC_DEFUN([_AM_PROG_XARGS_N],
+[AC_CACHE_CHECK([xargs -n works], am_cv_xargs_n_works, [dnl
+AS_IF([test "`echo 1 2 3 | xargs -n2 echo`" = "1 2
+3"], [am_cv_xargs_n_works=yes], [am_cv_xargs_n_works=no])])
+AS_IF([test "$am_cv_xargs_n_works" = yes], [am__xargs_n='xargs -n'], [dnl
+  am__xargs_n='am__xargs_n () { shift; sed "s/ /\\n/g" | while read am__xargs_n_arg; do "$@" "$am__xargs_n_arg"; done; }'
+])dnl
+AC_SUBST(am__xargs_n)
+])
+
 m4_include([scripts/autoconf/libtool.m4])
 m4_include([scripts/autoconf/ltoptions.m4])
 m4_include([scripts/autoconf/ltsugar.m4])
--- a/arm/arm_init.c
+++ b/arm/arm_init.c
@ -1,4 +1,3 @@
-
 /* arm_init.c - NEON optimised filter functions
 *
 * Copyright (c) 2018-2022 Cosmin Truta
@ -36,14 +35,14 @@
 #ifndef PNG_ARM_NEON_FILE
 #  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"
+#    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"
+#    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"
+#    error No support for run-time ARM Neon checking; use compile-time options
 #  endif
 #endif

@ -54,7 +53,7 @@ static int png_have_neon(png_structp png_ptr);
 #endif /* PNG_ARM_NEON_CHECK_SUPPORTED */

 #ifndef PNG_ALIGNED_MEMORY_SUPPORTED
-#  error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED"
+#  error ALIGNED_MEMORY is required; please define PNG_ALIGNED_MEMORY_SUPPORTED
 #endif

 void
--- a/arm/filter_neon.S
+++ b/arm/filter_neon.S
@ -1,253 +1,60 @@
-
-/* filter_neon.S - NEON optimised filter functions
+/* filter_neon.S - placeholder file
 *
- * Copyright (c) 2018 Cosmin Truta
- * Copyright (c) 2014,2017 Glenn Randers-Pehrson
- * Written by Mans Rullgard, 2011.
+ * Copyright (c) 2024 Cosmin Truta
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
 * and license in png.h
 */

+/* IMPORTANT NOTE:
+ *
+ * Historically, the hand-coded assembler implementation of Neon optimizations
+ * in this module had not been in sync with the intrinsics-based implementation
+ * in filter_neon_intrinsics.c and palette_neon_intrinsics.c, at least since
+ * the introduction of riffled palette optimizations. Moreover, the assembler
+ * code used to work on 32-bit ARM only, and it caused problems, even if empty,
+ * on 64-bit ARM.
+ *
+ * All references to this module from our internal build scripts and projects
+ * have been removed.
+ *
+ * For the external projects that might still expect this module to be present,
+ * we leave this stub in place, for the remaining lifetime of libpng-1.6.x.
+ * Everything should continue to function normally, as long as there are no
+ * deliberate attempts to use the old hand-made assembler code. A build error
+ * will be raised otherwise.
+ */
+
 /* This is required to get the symbol renames, which are #defines, and the
 * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION.
 */
 #define PNG_VERSION_INFO_ONLY
 #include "../pngpriv.h"

-#if (defined(__linux__) || defined(__FreeBSD__)) && defined(__ELF__)
-.section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
-#endif
-
 #ifdef PNG_READ_SUPPORTED
-
-/* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for
- * ARM64).  The code in arm/filter_neon_intrinsics.c supports ARM64, however it
- * only works if -mfpu=neon is specified on the GCC command line.  See pngpriv.h
- * for the logic which sets PNG_USE_ARM_NEON_ASM:
- */
 #if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */
-
 #if PNG_ARM_NEON_OPT > 0

-#ifdef __ELF__
-#   define ELF
+#if defined(__clang__)
+#define GNUC_VERSION 0 /* not gcc, although it might pretend to be */
+#elif defined(__GNUC__)
+#define GNUC_MAJOR (__GNUC__ + 0)
+#define GNUC_MINOR (__GNUC_MINOR__ + 0)
+#define GNUC_PATCHLEVEL (__GNUC_PATCHLEVEL__ + 0)
+#define GNUC_VERSION (GNUC_MAJOR * 10000 + GNUC_MINOR * 100 + GNUC_PATCHLEVEL)
 #else
-#   define ELF @
+#define GNUC_VERSION 0 /* not gcc */
 #endif

-        .arch armv7-a
-        .fpu  neon
+#if (GNUC_VERSION > 0) && (GNUC_VERSION < 40300)
+#error "PNG_ARM_NEON is not supported with gcc versions earlier than 4.3.0"
+#elif GNUC_VERSION == 40504
+#error "PNG_ARM_NEON is not supported with gcc version 4.5.4"
+#else
+#error "Please use 'arm/*_neon_intrinsics.c' for PNG_ARM_NEON support"
+#endif

-.macro  func    name, export=0
-    .macro endfunc
-ELF     .size   \name, . - \name
-        .endfunc
-        .purgem endfunc
-    .endm
-        .text
-
-        /* Explicitly specifying alignment here because some versions of
-         * GAS don't align code correctly.  This is harmless in correctly
-         * written versions of GAS.
-         */
-        .align 2
-
-    .if \export
-        .global \name
-    .endif
-ELF     .type   \name, STT_FUNC
-        .func   \name
-\name:
-.endm
-
-func    png_read_filter_row_sub4_neon, export=1
-        ldr             r3,  [r0, #4]           @ rowbytes
-        vmov.i8         d3,  #0
-1:
-        vld4.32         {d4[],d5[],d6[],d7[]},    [r1,:128]
-        vadd.u8         d0,  d3,  d4
-        vadd.u8         d1,  d0,  d5
-        vadd.u8         d2,  d1,  d6
-        vadd.u8         d3,  d2,  d7
-        vst4.32         {d0[0],d1[0],d2[0],d3[0]},[r1,:128]!
-        subs            r3,  r3,  #16
-        bgt             1b
-
-        bx              lr
-endfunc
-
-func    png_read_filter_row_sub3_neon, export=1
-        ldr             r3,  [r0, #4]           @ rowbytes
-        vmov.i8         d3,  #0
-        mov             r0,  r1
-        mov             r2,  #3
-        mov             r12, #12
-        vld1.8          {q11},    [r0], r12
-1:
-        vext.8          d5,  d22, d23, #3
-        vadd.u8         d0,  d3,  d22
-        vext.8          d6,  d22, d23, #6
-        vadd.u8         d1,  d0,  d5
-        vext.8          d7,  d23, d23, #1
-        vld1.8          {q11},    [r0], r12
-        vst1.32         {d0[0]},  [r1,:32], r2
-        vadd.u8         d2,  d1,  d6
-        vst1.32         {d1[0]},  [r1], r2
-        vadd.u8         d3,  d2,  d7
-        vst1.32         {d2[0]},  [r1], r2
-        vst1.32         {d3[0]},  [r1], r2
-        subs            r3,  r3,  #12
-        bgt             1b
-
-        bx              lr
-endfunc
-
-func    png_read_filter_row_up_neon, export=1
-        ldr             r3,  [r0, #4]           @ rowbytes
-1:
-        vld1.8          {q0}, [r1,:128]
-        vld1.8          {q1}, [r2,:128]!
-        vadd.u8         q0,  q0,  q1
-        vst1.8          {q0}, [r1,:128]!
-        subs            r3,  r3,  #16
-        bgt             1b
-
-        bx              lr
-endfunc
-
-func    png_read_filter_row_avg4_neon, export=1
-        ldr             r12, [r0, #4]           @ rowbytes
-        vmov.i8         d3,  #0
-1:
-        vld4.32         {d4[],d5[],d6[],d7[]},    [r1,:128]
-        vld4.32         {d16[],d17[],d18[],d19[]},[r2,:128]!
-        vhadd.u8        d0,  d3,  d16
-        vadd.u8         d0,  d0,  d4
-        vhadd.u8        d1,  d0,  d17
-        vadd.u8         d1,  d1,  d5
-        vhadd.u8        d2,  d1,  d18
-        vadd.u8         d2,  d2,  d6
-        vhadd.u8        d3,  d2,  d19
-        vadd.u8         d3,  d3,  d7
-        vst4.32         {d0[0],d1[0],d2[0],d3[0]},[r1,:128]!
-        subs            r12, r12, #16
-        bgt             1b
-
-        bx              lr
-endfunc
-
-func    png_read_filter_row_avg3_neon, export=1
-        push            {r4,lr}
-        ldr             r12, [r0, #4]           @ rowbytes
-        vmov.i8         d3,  #0
-        mov             r0,  r1
-        mov             r4,  #3
-        mov             lr,  #12
-        vld1.8          {q11},    [r0], lr
-1:
-        vld1.8          {q10},    [r2], lr
-        vext.8          d5,  d22, d23, #3
-        vhadd.u8        d0,  d3,  d20
-        vext.8          d17, d20, d21, #3
-        vadd.u8         d0,  d0,  d22
-        vext.8          d6,  d22, d23, #6
-        vhadd.u8        d1,  d0,  d17
-        vext.8          d18, d20, d21, #6
-        vadd.u8         d1,  d1,  d5
-        vext.8          d7,  d23, d23, #1
-        vld1.8          {q11},    [r0], lr
-        vst1.32         {d0[0]},  [r1,:32], r4
-        vhadd.u8        d2,  d1,  d18
-        vst1.32         {d1[0]},  [r1], r4
-        vext.8          d19, d21, d21, #1
-        vadd.u8         d2,  d2,  d6
-        vhadd.u8        d3,  d2,  d19
-        vst1.32         {d2[0]},  [r1], r4
-        vadd.u8         d3,  d3,  d7
-        vst1.32         {d3[0]},  [r1], r4
-        subs            r12, r12, #12
-        bgt             1b
-
-        pop             {r4,pc}
-endfunc
-
-.macro  paeth           rx,  ra,  rb,  rc
-        vaddl.u8        q12, \ra, \rb           @ a + b
-        vaddl.u8        q15, \rc, \rc           @ 2*c
-        vabdl.u8        q13, \rb, \rc           @ pa
-        vabdl.u8        q14, \ra, \rc           @ pb
-        vabd.u16        q15, q12, q15           @ pc
-        vcle.u16        q12, q13, q14           @ pa <= pb
-        vcle.u16        q13, q13, q15           @ pa <= pc
-        vcle.u16        q14, q14, q15           @ pb <= pc
-        vand            q12, q12, q13           @ pa <= pb && pa <= pc
-        vmovn.u16       d28, q14
-        vmovn.u16       \rx, q12
-        vbsl            d28, \rb, \rc
-        vbsl            \rx, \ra, d28
-.endm
-
-func    png_read_filter_row_paeth4_neon, export=1
-        ldr             r12, [r0, #4]           @ rowbytes
-        vmov.i8         d3,  #0
-        vmov.i8         d20, #0
-1:
-        vld4.32         {d4[],d5[],d6[],d7[]},    [r1,:128]
-        vld4.32         {d16[],d17[],d18[],d19[]},[r2,:128]!
-        paeth           d0,  d3,  d16, d20
-        vadd.u8         d0,  d0,  d4
-        paeth           d1,  d0,  d17, d16
-        vadd.u8         d1,  d1,  d5
-        paeth           d2,  d1,  d18, d17
-        vadd.u8         d2,  d2,  d6
-        paeth           d3,  d2,  d19, d18
-        vmov            d20, d19
-        vadd.u8         d3,  d3,  d7
-        vst4.32         {d0[0],d1[0],d2[0],d3[0]},[r1,:128]!
-        subs            r12, r12, #16
-        bgt             1b
-
-        bx              lr
-endfunc
-
-func    png_read_filter_row_paeth3_neon, export=1
-        push            {r4,lr}
-        ldr             r12, [r0, #4]           @ rowbytes
-        vmov.i8         d3,  #0
-        vmov.i8         d4,  #0
-        mov             r0,  r1
-        mov             r4,  #3
-        mov             lr,  #12
-        vld1.8          {q11},    [r0], lr
-1:
-        vld1.8          {q10},    [r2], lr
-        paeth           d0,  d3,  d20, d4
-        vext.8          d5,  d22, d23, #3
-        vadd.u8         d0,  d0,  d22
-        vext.8          d17, d20, d21, #3
-        paeth           d1,  d0,  d17, d20
-        vst1.32         {d0[0]},  [r1,:32], r4
-        vext.8          d6,  d22, d23, #6
-        vadd.u8         d1,  d1,  d5
-        vext.8          d18, d20, d21, #6
-        paeth           d2,  d1,  d18, d17
-        vext.8          d7,  d23, d23, #1
-        vld1.8          {q11},    [r0], lr
-        vst1.32         {d1[0]},  [r1], r4
-        vadd.u8         d2,  d2,  d6
-        vext.8          d19, d21, d21, #1
-        paeth           d3,  d2,  d19, d18
-        vst1.32         {d2[0]},  [r1], r4
-        vmov            d4,  d19
-        vadd.u8         d3,  d3,  d7
-        vst1.32         {d3[0]},  [r1], r4
-        subs            r12, r12, #12
-        bgt             1b
-
-        pop             {r4,pc}
-endfunc
 #endif /* PNG_ARM_NEON_OPT > 0 */
-#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 */
 #endif /* READ */
--- a/arm/filter_neon_intrinsics.c
+++ b/arm/filter_neon_intrinsics.c
@ -1,4 +1,3 @@
-
 /* filter_neon_intrinsics.c - NEON optimised filter functions
 *
 * Copyright (c) 2018 Cosmin Truta
--- a/arm/palette_neon_intrinsics.c
+++ b/arm/palette_neon_intrinsics.c
@ -1,4 +1,3 @@
-
 /* palette_neon_intrinsics.c - NEON optimised palette expansion functions
 *
 * Copyright (c) 2018-2019 Cosmin Truta
@ -64,7 +63,7 @@ png_do_expand_palette_rgba8_neon(png_structrp png_ptr, png_row_infop row_info,
 {
   png_uint_32 row_width = row_info->width;
   const png_uint_32 *riffled_palette =
-      (const png_uint_32 *)png_ptr->riffled_palette;
+      png_aligncastconst(png_const_uint_32p, png_ptr->riffled_palette);
   const png_uint_32 pixels_per_chunk = 4;
   png_uint_32 i;

--- a/ci/README.md
+++ b/ci/README.md
@ -0,0 +1,25 @@
+Scripts for the Continuous Integration of the PNG Reference Library
+===================================================================
+
+Copyright Notice
+----------------
+
+Copyright (c) 2019-2025 Cosmin Truta.
+
+Use, modification and distribution are subject to the MIT License.
+Please see the accompanying file `LICENSE_MIT.txt` or visit
+https://opensource.org/license/mit
+
+File List
+---------
+
+    LICENSE_MIT.txt         ==>  The License file
+    README.md               ==>  This file
+    ci_lint.sh              ==>  Lint the source code
+    ci_shellify.sh          ==>  Convert select definitions to shell syntax
+    ci_verify_cmake.sh      ==>  Verify the build driven by CMakeLists.txt
+    ci_verify_configure.sh  ==>  Verify the build driven by configure
+    ci_verify_makefiles.sh  ==>  Verify the build driven by scripts/makefile.*
+    ci_verify_version.sh    ==>  Verify the consistency of version definitions
+    lib/ci.lib.sh           ==>  Shell utilities for the main ci_*.sh scripts
+    targets/*/ci_env.*.sh   ==>  Shell environments for cross-platform testing
--- a/ci/ci_lint.sh
+++ b/ci/ci_lint.sh
@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -o errexit -o pipefail -o posix

-# Copyright (c) 2019-2024 Cosmin Truta.
+# Copyright (c) 2019-2025 Cosmin Truta.
 #
 # Use, modification and distribution are subject to the MIT License.
 # Please see the accompanying file LICENSE_MIT.txt
@ -61,7 +61,7 @@ function ci_lint_ci_scripts {
    }
    ci_info "## LINTING: CI scripts ##"
    ci_spawn "$CI_SHELLCHECK" --version
-    find ./ci -maxdepth 1 -name "*.sh" | {
+    find ./ci -name "ci_*.sh" -not -name "ci_env.*.sh" | {
        local my_file
        while IFS="" read -r my_file
        do
@ -80,7 +80,7 @@ function ci_lint_text_files {
    }
    ci_info "## LINTING: text files ##"
    ci_spawn "$CI_EDITORCONFIG_CHECKER" --version
-    ci_spawn "$CI_EDITORCONFIG_CHECKER" || {
+    ci_spawn "$CI_EDITORCONFIG_CHECKER" --config .editorconfig-checker.json || {
        # Linting failed.
        return 1
    }
@ -93,7 +93,9 @@ function ci_lint_yaml_files {
    }
    ci_info "## LINTING: YAML files ##"
    ci_spawn "$CI_YAMLLINT" --version
-    find . \( -iname "*.yml" -o -iname "*.yaml" \) -not -path "./out/*" | {
+    # Considering that the YAML format is an extension of the JSON format,
+    # we can lint both the YAML files and the plain JSON files here.
+    find . \( -iname "*.yml" -o -iname "*.yaml" -o -iname "*.json" \) -not -path "./out/*" | {
        local my_file
        while IFS="" read -r my_file
        do
--- a/ci/ci_shellify.sh
+++ b/ci/ci_shellify.sh
@ -1,92 +0,0 @@
-#!/usr/bin/env bash
-set -o errexit -o pipefail -o posix
-
-# 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"
-
-function ci_shellify_c {
-    # Convert C preprocessor text, specifically originating
-    # from png.h, to shell scripting text.
-    # Select only the easy-to-parse definitions of PNG_LIBPNG_*.
-    sed -n -e '/^\# *define * PNG_LIBPNG_[^ ]* * ["0-9A-Za-z_]/ p' |
-        sed -e 's/^\# *define * PNG\([^ ]*\) * \([^ ]*\)/PNG\1=\2/' \
-            -e 's/=PNG\([0-9A-Za-z_]*\)/=\${PNG\1}/' \
-            -e 's/^\([^ ]*=[^ ]*\).*$/export \1;/'
-}
-
-function ci_shellify_autoconf {
-    # Convert autoconf (M4) text, specifically originating
-    # from configure.ac, to shell scripting text.
-    # Select only the easy-to-parse definitions of PNGLIB_*.
-    sed -n -e '/^ *PNGLIB_[^ ]*=[$"0-9A-Za-z_]/ p' |
-        sed -e 's/^ *PNG\([0-9A-Za-z_]*\)=\([^# ]*\).*$/PNG\1=\2/' \
-            -e 's/^\([^ ]*=[^ ]*\).*$/export \1;/'
-}
-
-function ci_shellify_cmake {
-    # Convert CMake lists text, specifically originating
-    # from CMakeLists.txt, to shell scripting text.
-    # Select only the easy-to-parse definitions of PNGLIB_*.
-    sed -n -e '/^ *set *(PNGLIB_[^ ]* * [$"0-9A-Za-z_].*)/ p' |
-        sed -e 's/^ *set *(PNG\([^ ]*\) * \([^() ]*\)).*$/PNG\1=\2/' \
-            -e 's/^\([^ ]*=[^ ]*\).*$/export \1;/'
-}
-
-function ci_shellify {
-    local arg filename
-    for arg in "$@"
-    do
-        test -f "$arg" || ci_err "no such file: '$arg'"
-        filename="$(basename -- "$arg")"
-        case "$filename" in
-        ( *.[ch] )
-            [[ $filename == png.h ]] || {
-                ci_err "unable to shellify: '$filename' (expecting: 'png.h')"
-            }
-            ci_shellify_c <"$arg" ;;
-        ( config* | *.ac )
-            [[ $filename == configure.ac ]] || {
-                ci_err "unable to shellify: '$filename' (expecting: 'configure.ac')"
-            }
-            ci_shellify_autoconf <"$arg" ;;
-        ( *CMake* | *cmake* | *.txt )
-            [[ $filename == [Cc][Mm]ake[Ll]ists.txt ]] || {
-                ci_err "unable to shellify: '$filename' (expecting: 'CMakeLists.txt')"
-            }
-            ci_shellify_cmake <"$arg" ;;
-        ( * )
-            ci_err "unable to shellify: '$arg'" ;;
-        esac
-    done
-}
-
-function usage {
-    echo "usage: $CI_SCRIPT_NAME [<options>] <files>..."
-    echo "options: -?|-h|--help"
-    echo "files: png.h|configure.ac|CMakeLists.txt"
-    exit "${@:-0}"
-}
-
-function main {
-    local opt
-    while getopts ":" opt
-    do
-        # This ain't a while-loop. It only pretends to be.
-        [[ $1 == -[?h]* || $1 == --help || $1 == --help=* ]] && usage 0
-        ci_err "unknown option: '$1'"
-    done
-    shift $((OPTIND - 1))
-    [[ $# -eq 0 ]] && usage 2
-    # And... go!
-    ci_shellify "$@"
-}
-
-main "$@"
--- a/ci/ci_verify_cmake.sh
+++ b/ci/ci_verify_cmake.sh
@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -o errexit -o pipefail -o posix

-# Copyright (c) 2019-2024 Cosmin Truta.
+# Copyright (c) 2019-2025 Cosmin Truta.
 #
 # Use, modification and distribution are subject to the MIT License.
 # Please see the accompanying file LICENSE_MIT.txt
@ -17,12 +17,6 @@ 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="${CI_CMAKE:-cmake}"
@ -70,6 +64,7 @@ function ci_trace_build {
    ci_info "environment option: \$CI_RANLIB: '$CI_RANLIB'"
    ci_info "environment option: \$CI_SANITIZERS: '$CI_SANITIZERS'"
    ci_info "environment option: \$CI_FORCE: '$CI_FORCE'"
+    ci_info "environment option: \$CI_NO_BUILD: '$CI_NO_BUILD'"
    ci_info "environment option: \$CI_NO_TEST: '$CI_NO_TEST'"
    ci_info "environment option: \$CI_NO_INSTALL: '$CI_NO_INSTALL'"
    ci_info "environment option: \$CI_NO_CLEAN: '$CI_NO_CLEAN'"
@ -148,40 +143,35 @@ function ci_build {
    all_cmake_build_flags+=($CI_CMAKE_BUILD_FLAGS)
    all_ctest_flags+=($CI_CTEST_FLAGS)
    # And... 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_spawn "$CI_CMAKE" -B "$CI_BUILD_DIR" \
+                         -S . \
+                         -DCMAKE_INSTALL_PREFIX="$CI_INSTALL_DIR" \
+                         "${all_cmake_vars[@]}"
+    ci_expr $((CI_NO_BUILD)) || {
+        # Spawn "cmake --build ...".
+        ci_spawn "$CI_CMAKE" --build "$CI_BUILD_DIR" \
+                             --config "$CI_CMAKE_BUILD_TYPE" \
+                             "${all_cmake_build_flags[@]}"
+    }
    ci_expr $((CI_NO_TEST)) || {
        # Spawn "ctest" if testing is not disabled.
+        ci_spawn pushd "$CI_BUILD_DIR"
        ci_spawn "$CI_CTEST" --build-config "$CI_CMAKE_BUILD_TYPE" \
                             "${all_ctest_flags[@]}"
+        ci_spawn popd
    }
    ci_expr $((CI_NO_INSTALL)) || {
        # Spawn "cmake --build ... --target install" if installation is not disabled.
-        ci_spawn "$CI_CMAKE" --build . \
+        ci_spawn "$CI_CMAKE" --build "$CI_BUILD_DIR" \
                             --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 . \
+        ci_spawn "$CI_CMAKE" --build "$CI_BUILD_DIR" \
                             --config "$CI_CMAKE_BUILD_TYPE" \
                             --target clean \
                             "${all_cmake_build_flags[@]}"
--- a/ci/ci_verify_configure.sh
+++ b/ci/ci_verify_configure.sh
@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -o errexit -o pipefail -o posix

-# Copyright (c) 2019-2024 Cosmin Truta.
+# Copyright (c) 2019-2025 Cosmin Truta.
 #
 # Use, modification and distribution are subject to the MIT License.
 # Please see the accompanying file LICENSE_MIT.txt
@ -58,6 +58,7 @@ function ci_trace_build {
    ci_info "environment option: \$CI_LD_FLAGS: '$CI_LD_FLAGS'"
    ci_info "environment option: \$CI_SANITIZERS: '$CI_SANITIZERS'"
    ci_info "environment option: \$CI_FORCE: '$CI_FORCE'"
+    ci_info "environment option: \$CI_NO_BUILD: '$CI_NO_BUILD'"
    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: '$CI_NO_CLEAN'"
@ -122,13 +123,19 @@ function ci_build {
        ci_spawn export CFLAGS="${CFLAGS:-"-O2"} -fsanitize=$CI_SANITIZERS"
        ci_spawn export LDFLAGS="${LDFLAGS}${LDFLAGS:+" "}-fsanitize=$CI_SANITIZERS"
    }
+    # Spawn "autogen.sh" if the configure script is not available.
+    [[ -x "$CI_SRC_DIR/configure" ]] || {
+        ci_spawn "$CI_SRC_DIR/autogen.sh" --maintainer
+    }
    # And... 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 $((CI_NO_BUILD)) || {
+        # Spawn "make".
+        ci_spawn "$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
--- a/ci/ci_verify_makefiles.sh
+++ b/ci/ci_verify_makefiles.sh
@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -o errexit -o pipefail -o posix

-# Copyright (c) 2019-2024 Cosmin Truta.
+# Copyright (c) 2019-2025 Cosmin Truta.
 #
 # Use, modification and distribution are subject to the MIT License.
 # Please see the accompanying file LICENSE_MIT.txt
@ -51,6 +51,7 @@ function ci_trace_build {
    ci_info "environment option: \$CI_LIBS: '$CI_LIBS'"
    ci_info "environment option: \$CI_SANITIZERS: '$CI_SANITIZERS'"
    ci_info "environment option: \$CI_FORCE: '$CI_FORCE'"
+    ci_info "environment option: \$CI_NO_BUILD: '$CI_NO_BUILD'"
    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")"
@ -145,10 +146,12 @@ function ci_build {
    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 $((CI_NO_BUILD)) || {
+            # Spawn "make".
+            ci_spawn "$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" \
--- a/ci/ci_verify_version.sh
+++ b/ci/ci_verify_version.sh
@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -o errexit -o pipefail -o posix

-# Copyright (c) 2019-2024 Cosmin Truta.
+# Copyright (c) 2019-2025 Cosmin Truta.
 #
 # Use, modification and distribution are subject to the MIT License.
 # Please see the accompanying file LICENSE_MIT.txt
@ -12,33 +12,43 @@ set -o errexit -o pipefail -o posix
 source "$(dirname "$0")/lib/ci.lib.sh"
 cd "$CI_TOPLEVEL_DIR"

-function ci_init_shellify {
-    [[ -f $CI_SCRIPT_DIR/ci_shellify.sh ]] || {
-        ci_err_internal "missing script: '$CI_SCRIPT_DIR/ci_shellify.sh'"
-    }
-}
+# Declare the global environments collected from various sources.
+declare CI_ENV_LIBPNG_VER        # collected from png.h
+declare CI_ENV_AUTOCONF_VER      # collected from configure.ac
+declare CI_ENV_CMAKE_VER         # collected from CMakeLists.txt
+declare CI_ENV_LIBPNGCONFIG_VER  # collected from scripts/libpng-config-head.in

 function ci_run_shellify {
+    local my_script my_result
+    my_script="$CI_SCRIPT_DIR/libexec/ci_shellify_${1#--}.sh"
+    shift 1
+    [[ -f $my_script ]] || {
+        ci_err_internal "missing script: '$my_script'"
+    }
    ci_info "shellifying:" "$@"
-    local my_result
-    "$BASH" "$CI_SCRIPT_DIR/ci_shellify.sh" "$@"
+    "$BASH" "$my_script" "$@"
    echo "$my_result" | "$BASH" --posix || ci_err "bad shellify output"
    echo "$my_result"
 }

-function ci_verify_version {
+function ci_init_version_verification {
    ci_info "## START OF VERIFICATION ##"
-    local my_env_libpng_ver my_env_autoconf_ver my_env_cmake_ver my_expect
-    ci_init_shellify
-    my_env_libpng_ver="$(ci_run_shellify png.h)"
-    echo "$my_env_libpng_ver"
-    my_env_autoconf_ver="$(ci_run_shellify configure.ac)"
-    echo "$my_env_autoconf_ver"
-    my_env_cmake_ver="$(ci_run_shellify CMakeLists.txt)"
-    echo "$my_env_cmake_ver"
-    ci_info "## VERIFYING: png.h version definitions ##"
-    eval "$my_env_libpng_ver"
-    local my_expect="${PNG_LIBPNG_VER_MAJOR}.${PNG_LIBPNG_VER_MINOR}.${PNG_LIBPNG_VER_RELEASE}"
+    CI_ENV_LIBPNG_VER="$(ci_run_shellify --c png.h)"
+    echo "$CI_ENV_LIBPNG_VER"
+    CI_ENV_AUTOCONF_VER="$(ci_run_shellify --autoconf configure.ac)"
+    echo "$CI_ENV_AUTOCONF_VER"
+    CI_ENV_CMAKE_VER="$(ci_run_shellify --cmake CMakeLists.txt)"
+    echo "$CI_ENV_CMAKE_VER"
+    CI_ENV_LIBPNGCONFIG_VER="$(ci_run_shellify --shell scripts/libpng-config-head.in)"
+    echo "$CI_ENV_LIBPNGCONFIG_VER"
+}
+
+# shellcheck disable=SC2154
+function ci_do_version_verification {
+    local my_expect
+    ci_info "## VERIFYING: version definitions in 'png.h' ##"
+    eval "$CI_ENV_LIBPNG_VER"
+    my_expect="${PNG_LIBPNG_VER_MAJOR}.${PNG_LIBPNG_VER_MINOR}.${PNG_LIBPNG_VER_RELEASE}"
    if [[ "$PNG_LIBPNG_VER_STRING" == "$my_expect"* ]]
    then
        ci_info "matched: \$PNG_LIBPNG_VER_STRING == $my_expect*"
@ -77,7 +87,7 @@ function ci_verify_version {
    else
        ci_err "mismatched: \$PNG_LIBPNG_VER_BUILD != [01]"
    fi
-    ci_info "## VERIFYING: png.h build definitions ##"
+    ci_info "## VERIFYING: build definitions in 'png.h' ##"
    my_expect="${PNG_LIBPNG_VER_MAJOR}.${PNG_LIBPNG_VER_MINOR}.${PNG_LIBPNG_VER_RELEASE}"
    if [[ "$PNG_LIBPNG_VER_STRING" == "$my_expect" ]]
    then
@ -89,9 +99,9 @@ function ci_verify_version {
        fi
        if [[ $PNG_LIBPNG_BUILD_BASE_TYPE -eq $PNG_LIBPNG_BUILD_STABLE ]]
        then
-            ci_info "matched: \$PNG_LIBPNG_BUILD_BASE_TYPE -eq \$PNG_LIBPNG_BUILD_BETA"
+            ci_info "matched: \$PNG_LIBPNG_BUILD_BASE_TYPE -eq \$PNG_LIBPNG_BUILD_STABLE"
        else
-            ci_err "mismatched: \$PNG_LIBPNG_BUILD_BASE_TYPE -ne \$PNG_LIBPNG_BUILD_BETA"
+            ci_err "mismatched: \$PNG_LIBPNG_BUILD_BASE_TYPE -ne \$PNG_LIBPNG_BUILD_STABLE"
        fi
    elif [[ "$PNG_LIBPNG_VER_STRING" == "$my_expect".git ]]
    then
@ -101,28 +111,28 @@ function ci_verify_version {
        else
            ci_err "mismatched: \$PNG_LIBPNG_VER_BUILD -eq 0"
        fi
-        if [[ $PNG_LIBPNG_BUILD_BASE_TYPE -eq $PNG_LIBPNG_BUILD_BETA ]]
+        if [[ $PNG_LIBPNG_BUILD_BASE_TYPE -ne $PNG_LIBPNG_BUILD_STABLE ]]
        then
-            ci_info "matched: \$PNG_LIBPNG_BUILD_BASE_TYPE -eq \$PNG_LIBPNG_BUILD_BETA"
+            ci_info "matched: \$PNG_LIBPNG_BUILD_BASE_TYPE -ne \$PNG_LIBPNG_BUILD_STABLE"
        else
-            ci_err "mismatched: \$PNG_LIBPNG_BUILD_BASE_TYPE -ne \$PNG_LIBPNG_BUILD_BETA"
+            ci_err "mismatched: \$PNG_LIBPNG_BUILD_BASE_TYPE -eq \$PNG_LIBPNG_BUILD_STABLE"
        fi
    else
        ci_err "unexpected: \$PNG_LIBPNG_VER_STRING == '$PNG_LIBPNG_VER_STRING'"
    fi
-    ci_info "## VERIFYING: png.h type definitions ##"
+    ci_info "## VERIFYING: type definitions in 'png.h' ##"
    my_expect="$(echo "png_libpng_version_${PNG_LIBPNG_VER_STRING}" | tr . _)"
    ci_spawn grep -w -e "$my_expect" png.h
-    ci_info "## VERIFYING: configure.ac version definitions ##"
-    eval "$my_env_autoconf_ver"
+    ci_info "## VERIFYING: version definitions in 'configure.ac' ##"
+    eval "$CI_ENV_AUTOCONF_VER"
    if [[ "$PNGLIB_VERSION" == "$PNG_LIBPNG_VER_STRING" ]]
    then
        ci_info "matched: \$PNGLIB_VERSION == \$PNG_LIBPNG_VER_STRING"
    else
        ci_err "mismatched: \$PNGLIB_VERSION != \$PNG_LIBPNG_VER_STRING"
    fi
-    ci_info "## VERIFYING: CMakeLists.txt version definitions ##"
-    eval "$my_env_cmake_ver"
+    ci_info "## VERIFYING: version definitions in 'CMakeLists.txt' ##"
+    eval "$CI_ENV_CMAKE_VER"
    if [[ "$PNGLIB_VERSION" == "$PNG_LIBPNG_VER_STRING" && "$PNGLIB_SUBREVISION" == 0 ]]
    then
        ci_info "matched: \$PNGLIB_VERSION == \$PNG_LIBPNG_VER_STRING"
@ -133,8 +143,26 @@ function ci_verify_version {
    else
        ci_err "mismatched: \$PNGLIB_VERSION != \$PNG_LIBPNG_VER_STRING"
    fi
+    ci_info "## VERIFYING: version definitions in 'scripts/libpng-config-head.in' ##"
+    eval "$CI_ENV_LIBPNGCONFIG_VER"
+    if [[ "$version" == "$PNG_LIBPNG_VER_STRING" ]]
+    then
+        ci_info "matched: \$version == \$PNG_LIBPNG_VER_STRING"
+    else
+        ci_err "mismatched: \$version != \$PNG_LIBPNG_VER_STRING"
+    fi
+}
+
+function ci_finish_version_verification {
    ci_info "## END OF VERIFICATION ##"
-    ci_info "success!"
+    # Relying on "set -o errexit" to not reach here in case of error.
+    ci_info "## SUCCESS ##"
+}
+
+function ci_verify_version {
+    ci_init_version_verification
+    ci_do_version_verification
+    ci_finish_version_verification
 }

 function usage {
--- a/ci/lib/ci.lib.sh
+++ b/ci/lib/ci.lib.sh
@ -1,4 +1,4 @@
-# Copyright (c) 2019-2024 Cosmin Truta.
+# Copyright (c) 2019-2025 Cosmin Truta.
 #
 # Use, modification and distribution are subject to the MIT License.
 # Please see the accompanying file LICENSE_MIT.txt
@ -91,6 +91,9 @@ function ci_spawn {
 [[ ${CI_FORCE:-0} == [01] ]] || {
    ci_err "bad boolean option: \$CI_FORCE: '$CI_FORCE'"
 }
+[[ ${CI_NO_BUILD:-0} == [01] ]] || {
+    ci_err "bad boolean option: \$CI_NO_BUILD: '$CI_NO_BUILD'"
+}
 [[ ${CI_NO_TEST:-0} == [01] ]] || {
    ci_err "bad boolean option: \$CI_NO_TEST: '$CI_NO_TEST'"
 }
@ -100,3 +103,9 @@ function ci_spawn {
 [[ ${CI_NO_CLEAN:-0} == [01] ]] || {
    ci_err "bad boolean option: \$CI_NO_CLEAN: '$CI_NO_CLEAN'"
 }
+if ci_expr $((CI_NO_BUILD))
+then
+    ci_expr $((CI_NO_TEST && CI_NO_INSTALL)) || {
+        ci_err "\$CI_NO_BUILD requires \$CI_NO_TEST and \$CI_NO_INSTALL"
+    }
+fi
--- a/ci/libexec/ci_shellify_autoconf.sh
+++ b/ci/libexec/ci_shellify_autoconf.sh
@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+set -o errexit -o pipefail -o posix
+
+# Copyright (c) 2019-2025 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+# shellcheck source=ci/lib/ci.lib.sh
+source "$(dirname "$0")/../lib/ci.lib.sh"
+
+function ci_shellify_autoconf {
+    # Convert autoconf (M4) text, specifically originating
+    # from configure.ac, to shell scripting text.
+    # Select only the easy-to-parse definitions of PNGLIB_*.
+    sed -n -e '/^ *PNGLIB_[^ ]*=[$"0-9A-Za-z_]/ p' |
+        sed -e 's/^ *PNG\([0-9A-Za-z_]*\)=\([^# ]*\).*$/PNG\1=\2/' \
+            -e 's/^\([^ ]*=[^ ]*\).*$/export \1;/'
+}
+
+function usage {
+    echo "usage: $CI_SCRIPT_NAME [<options>] configure.ac"
+    echo "options: -?|-h|--help"
+    exit "${@:-0}"
+}
+
+function main {
+    local opt
+    while getopts ":" opt
+    do
+        # This ain't a while-loop. It only pretends to be.
+        [[ $1 == -[?h]* || $1 == --help || $1 == --help=* ]] && usage 0
+        ci_err "unknown option: '$1'"
+    done
+    shift $((OPTIND - 1))
+    [[ $# -eq 0 ]] && usage 2
+    [[ $# -eq 1 ]] || ci_err "too many operands"
+    # And... go!
+    test -e "$1" || ci_err "no such file: '$1'"
+    [[ $(basename -- "$1") == configure.ac ]] || {
+        ci_err "incorrect operand: '$1' (expecting: 'configure.ac')"
+    }
+    ci_shellify_autoconf <"$1"
+}
+
+main "$@"
--- a/ci/libexec/ci_shellify_c.sh
+++ b/ci/libexec/ci_shellify_c.sh
@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+set -o errexit -o pipefail -o posix
+
+# Copyright (c) 2019-2025 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"
+
+function ci_shellify_c {
+    # Convert C preprocessor text, specifically originating
+    # from png.h, to shell scripting text.
+    # Select only the easy-to-parse definitions of PNG_LIBPNG_*.
+    sed -n -e '/^\# *define * PNG_LIBPNG_[^ ]* * ["0-9A-Za-z_]/ p' |
+        sed -e 's/^\# *define * PNG\([^ ]*\) * \([^ ]*\)/PNG\1=\2/' \
+            -e 's/=PNG\([0-9A-Za-z_]*\)/=\${PNG\1}/' \
+            -e 's/^\([^ ]*=[^ ]*\).*$/export \1;/'
+}
+
+function usage {
+    echo "usage: $CI_SCRIPT_NAME [<options>] png.h"
+    echo "options: -?|-h|--help"
+    exit "${@:-0}"
+}
+
+function main {
+    local opt
+    while getopts ":" opt
+    do
+        # This ain't a while-loop. It only pretends to be.
+        [[ $1 == -[?h]* || $1 == --help || $1 == --help=* ]] && usage 0
+        ci_err "unknown option: '$1'"
+    done
+    shift $((OPTIND - 1))
+    [[ $# -eq 0 ]] && usage 2
+    [[ $# -eq 1 ]] || ci_err "too many operands"
+    # And... go!
+    test -e "$1" || ci_err "no such file: '$1'"
+    [[ $(basename -- "$1") == png.h ]] || {
+        ci_err "incorrect operand: '$1' (expecting: 'png.h')"
+    }
+    ci_shellify_c <"$1"
+}
+
+main "$@"
--- a/ci/libexec/ci_shellify_cmake.sh
+++ b/ci/libexec/ci_shellify_cmake.sh
@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+set -o errexit -o pipefail -o posix
+
+# Copyright (c) 2019-2025 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 "$0")/../lib/ci.lib.sh"
+
+function ci_shellify_cmake {
+    # Convert CMake lists text, specifically originating
+    # from CMakeLists.txt, to shell scripting text.
+    # Select only the easy-to-parse definitions of PNGLIB_*.
+    sed -n -e '/^ *set *(PNGLIB_[^ ]* * [$"0-9A-Za-z_].*)/ p' |
+        sed -e 's/^ *set *(PNG\([^ ]*\) * \([^() ]*\)).*$/PNG\1=\2/' \
+            -e 's/^\([^ ]*=[^ ]*\).*$/export \1;/'
+}
+
+function usage {
+    echo "usage: $CI_SCRIPT_NAME [<options>] CMakeLists.txt"
+    echo "options: -?|-h|--help"
+    exit "${@:-0}"
+}
+
+function main {
+    local opt
+    while getopts ":" opt
+    do
+        # This ain't a while-loop. It only pretends to be.
+        [[ $1 == -[?h]* || $1 == --help || $1 == --help=* ]] && usage 0
+        ci_err "unknown option: '$1'"
+    done
+    shift $((OPTIND - 1))
+    [[ $# -eq 0 ]] && usage 2
+    [[ $# -eq 1 ]] || ci_err "too many operands"
+    # And... go!
+    test -e "$1" || ci_err "no such file: '$1'"
+    filename="$(basename -- "$1")"
+    [[ $filename == [Cc][Mm]ake[Ll]ists.txt ]] || {
+        ci_err "incorrect operand: '$1' (expecting: 'CMakeLists.txt')"
+    }
+    ci_shellify_cmake <"$1"
+}
+
+main "$@"
--- a/ci/libexec/ci_shellify_shell.sh
+++ b/ci/libexec/ci_shellify_shell.sh
@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+set -o errexit -o pipefail -o posix
+
+# Copyright (c) 2019-2025 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 "$0")/../lib/ci.lib.sh"
+
+function ci_shellify_shell {
+    # Convert shell scripting text to shell scripting text.
+    # Select only the easy-to-parse version definitions.
+    sed -n -e '/^ *[A-Za-z_][0-9A-Za-z_]*=[0-9][^ #]* *$/ p' |
+        sed -e 's/^ *\([^ ]*=[^ ]*\) *$/export \1;/'
+}
+
+function usage {
+    echo "usage: $CI_SCRIPT_NAME [<options>] libpng-config-head.in"
+    echo "options: -?|-h|--help"
+    exit "${@:-0}"
+}
+
+function main {
+    local opt
+    while getopts ":" opt
+    do
+        # This ain't a while-loop. It only pretends to be.
+        [[ $1 == -[?h]* || $1 == --help || $1 == --help=* ]] && usage 0
+        ci_err "unknown option: '$1'"
+    done
+    shift $((OPTIND - 1))
+    [[ $# -eq 0 ]] && usage 2
+    [[ $# -eq 1 ]] || ci_err "too many operands"
+    # And... go!
+    test -e "$1" || ci_err "no such file: '$1'"
+    [[ $(basename -- "$1") == libpng-config-head.in ]] || {
+        ci_err "incorrect operand: '$1' (expecting: 'libpng-config-head.in')"
+    }
+    ci_shellify_shell <"$1"
+}
+
+main "$@"
--- a/ci/targets/android/ci_env.aarch64-linux-android.sh
+++ b/ci/targets/android/ci_env.aarch64-linux-android.sh
@ -0,0 +1,16 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=aarch64
+export CI_TARGET_ARCHVER=aarch64
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=android
+export CI_TARGET_ABIVER=android29
+
+export CI_CC="$CI_TARGET_ARCHVER-$CI_TARGET_SYSTEM-$CI_TARGET_ABIVER-clang"
+export CI_AR="llvm-ar"
+export CI_RANLIB="llvm-ranlib"
--- a/ci/targets/android/ci_env.armv7a-linux-androideabi.sh
+++ b/ci/targets/android/ci_env.armv7a-linux-androideabi.sh
@ -0,0 +1,16 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=arm
+export CI_TARGET_ARCHVER=armv7a
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=androideabi
+export CI_TARGET_ABIVER=androideabi29
+
+export CI_CC="$CI_TARGET_ARCHVER-$CI_TARGET_SYSTEM-$CI_TARGET_ABIVER-clang"
+export CI_AR="llvm-ar"
+export CI_RANLIB="llvm-ranlib"
--- a/ci/targets/android/ci_env.i686-linux-android.sh
+++ b/ci/targets/android/ci_env.i686-linux-android.sh
@ -0,0 +1,16 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=i686
+export CI_TARGET_ARCHVER=i686
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=android
+export CI_TARGET_ABIVER=android29
+
+export CI_CC="$CI_TARGET_ARCHVER-$CI_TARGET_SYSTEM-$CI_TARGET_ABIVER-clang"
+export CI_AR="llvm-ar"
+export CI_RANLIB="llvm-ranlib"
--- a/ci/targets/android/ci_env.x86_64-linux-android.sh
+++ b/ci/targets/android/ci_env.x86_64-linux-android.sh
@ -0,0 +1,16 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=x86_64
+export CI_TARGET_ARCHVER=x86_64
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=android
+export CI_TARGET_ABIVER=android29
+
+export CI_CC="$CI_TARGET_ARCHVER-$CI_TARGET_SYSTEM-$CI_TARGET_ABIVER-clang"
+export CI_AR="llvm-ar"
+export CI_RANLIB="llvm-ranlib"
--- a/ci/targets/cygwin/ci_env.i686-pc-cygwin.sh
+++ b/ci/targets/cygwin/ci_env.i686-pc-cygwin.sh
@ -0,0 +1,18 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=i686
+export CI_TARGET_SYSTEM=cygwin
+
+export CI_CC="$CI_TARGET_ARCH-pc-$CI_TARGET_SYSTEM-gcc"
+export CI_AR="$CI_CC-ar"
+export CI_RANLIB="$CI_CC-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=CYGWIN
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/cygwin/ci_env.x86_64-pc-cygwin.sh
+++ b/ci/targets/cygwin/ci_env.x86_64-pc-cygwin.sh
@ -0,0 +1,18 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=x86_64
+export CI_TARGET_SYSTEM=cygwin
+
+export CI_CC="$CI_TARGET_ARCH-pc-$CI_TARGET_SYSTEM-gcc"
+export CI_AR="$CI_CC-ar"
+export CI_RANLIB="$CI_CC-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=CYGWIN
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/darwin/ci_env.arm64-apple-darwin.sh
+++ b/ci/targets/darwin/ci_env.arm64-apple-darwin.sh
@ -0,0 +1,15 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=arm64
+export CI_TARGET_SYSTEM=darwin
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Darwin
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+    -DCMAKE_OSX_ARCHITECTURES=$CI_TARGET_ARCH
+"
--- a/ci/targets/darwin/ci_env.x86_64-apple-darwin.sh
+++ b/ci/targets/darwin/ci_env.x86_64-apple-darwin.sh
@ -0,0 +1,15 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=x86_64
+export CI_TARGET_SYSTEM=darwin
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Darwin
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+    -DCMAKE_OSX_ARCHITECTURES=$CI_TARGET_ARCH
+"
--- a/ci/targets/freebsd/ci_env.aarch64-unknown-freebsd.sh
+++ b/ci/targets/freebsd/ci_env.aarch64-unknown-freebsd.sh
@ -0,0 +1,14 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=aarch64
+export CI_TARGET_SYSTEM=freebsd
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=FreeBSD
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/freebsd/ci_env.i686-unknown-freebsd.sh
+++ b/ci/targets/freebsd/ci_env.i686-unknown-freebsd.sh
@ -0,0 +1,14 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=i686
+export CI_TARGET_SYSTEM=freebsd
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=FreeBSD
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/freebsd/ci_env.riscv64-unknown-freebsd.sh
+++ b/ci/targets/freebsd/ci_env.riscv64-unknown-freebsd.sh
@ -0,0 +1,14 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=riscv64
+export CI_TARGET_SYSTEM=freebsd
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=FreeBSD
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/freebsd/ci_env.x86_64-unknown-freebsd.sh
+++ b/ci/targets/freebsd/ci_env.x86_64-unknown-freebsd.sh
@ -0,0 +1,14 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=x86_64
+export CI_TARGET_SYSTEM=freebsd
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=FreeBSD
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.aarch64-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.aarch64-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=aarch64
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.arm-linux-gnueabi.sh
+++ b/ci/targets/linux/ci_env.arm-linux-gnueabi.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=arm
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnueabi
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.arm-linux-gnueabihf.sh
+++ b/ci/targets/linux/ci_env.arm-linux-gnueabihf.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=arm
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnueabihf
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.i686-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.i686-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=i686
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.mips-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.mips-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=mips
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.mips64-linux-gnuabi64.sh
+++ b/ci/targets/linux/ci_env.mips64-linux-gnuabi64.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=mips64
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnuabi64
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.mips64el-linux-gnuabi64.sh
+++ b/ci/targets/linux/ci_env.mips64el-linux-gnuabi64.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=mips64el
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnuabi64
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.mipsel-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.mipsel-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=mipsel
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.mipsisa32r6-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.mipsisa32r6-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=mipsisa32r6
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.mipsisa32r6el-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.mipsisa32r6el-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=mipsisa32r6el
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.mipsisa64r6-linux-gnuabi64.sh
+++ b/ci/targets/linux/ci_env.mipsisa64r6-linux-gnuabi64.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=mipsisa64r6
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnuabi64
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.mipsisa64r6el-linux-gnuabi64.sh
+++ b/ci/targets/linux/ci_env.mipsisa64r6el-linux-gnuabi64.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=mipsisa64r6el
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnuabi64
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.powerpc-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.powerpc-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=powerpc
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.powerpc64-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.powerpc64-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=powerpc64
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.powerpc64le-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.powerpc64le-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=powerpc64le
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.riscv64-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.riscv64-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=riscv64
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/linux/ci_env.x86_64-linux-gnu.sh
+++ b/ci/targets/linux/ci_env.x86_64-linux-gnu.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=x86_64
+export CI_TARGET_SYSTEM=linux
+export CI_TARGET_ABI=gnu
+
+export CI_GCC="${CI_GCC-gcc}"
+
+export CI_CC="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-$CI_GCC"
+export CI_AR="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ar"
+export CI_RANLIB="$CI_TARGET_ARCH-$CI_TARGET_SYSTEM-$CI_TARGET_ABI-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Linux
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/msdos/ci_env.i386-pc-msdoswatcom.sh
+++ b/ci/targets/msdos/ci_env.i386-pc-msdoswatcom.sh
@ -0,0 +1,18 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=i386
+export CI_TARGET_SYSTEM=msdoswatcom
+
+export CI_CC="wcl386"
+
+# Open Watcom V2 CMake build
+# https://github.com/open-watcom/open-watcom-v2/discussions/716
+export CI_CMAKE_GENERATOR="Watcom WMake"
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=DOS
+"
--- a/ci/targets/msdos/ci_env.i586-pc-msdosdjgpp.sh
+++ b/ci/targets/msdos/ci_env.i586-pc-msdosdjgpp.sh
@ -0,0 +1,18 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=i586
+export CI_TARGET_SYSTEM=msdosdjgpp
+
+export CI_CC="$CI_TARGET_ARCH-pc-$CI_TARGET_SYSTEM-gcc"
+export CI_AR="$CI_CC-ar"
+export CI_RANLIB="$CI_CC-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Generic
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/msdos/ci_env.i86-pc-msdoswatcom.sh
+++ b/ci/targets/msdos/ci_env.i86-pc-msdoswatcom.sh
@ -0,0 +1,19 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=i86
+export CI_TARGET_SYSTEM=msdoswatcom
+
+export CI_CC="wcl"
+
+# Open Watcom V2 CMake build
+# https://github.com/open-watcom/open-watcom-v2/discussions/716
+export CI_CMAKE_GENERATOR="Watcom WMake"
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=DOS
+    -DCMAKE_SYSTEM_PROCESSOR=I86
+"
--- a/ci/targets/windows/ci_env.aarch64-windows-llvm.sh
+++ b/ci/targets/windows/ci_env.aarch64-windows-llvm.sh
@ -0,0 +1,18 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=aarch64
+export CI_TARGET_SYSTEM=windows
+
+export CI_CC="clang"
+export CI_AR="llvm-ar"
+export CI_RANLIB="llvm-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Windows
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/windows/ci_env.i686-w64-mingw32.sh
+++ b/ci/targets/windows/ci_env.i686-w64-mingw32.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=i686
+export CI_TARGET_SYSTEM=mingw32
+
+# The output of `uname -s` on MSYS2 is understandable, and so is
+# CI_TARGET_SYSTEM above, in simplified form. (See also Cygwin.)
+# But aside from that, the Mingw-w64 nomenclature is rather messy.
+export CI_CC="$CI_TARGET_ARCH-w64-mingw32-gcc"
+export CI_AR="$CI_CC-ar"
+export CI_RANLIB="$CI_CC-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Windows
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/windows/ci_env.i686-windows-llvm.sh
+++ b/ci/targets/windows/ci_env.i686-windows-llvm.sh
@ -0,0 +1,18 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=i686
+export CI_TARGET_SYSTEM=windows
+
+export CI_CC="clang"
+export CI_AR="llvm-ar"
+export CI_RANLIB="llvm-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Windows
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/windows/ci_env.x86_64-w64-mingw32.sh
+++ b/ci/targets/windows/ci_env.x86_64-w64-mingw32.sh
@ -0,0 +1,21 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=x86_64
+export CI_TARGET_SYSTEM=mingw64
+
+# The output of `uname -s` on MSYS2 is understandable, and so is
+# CI_TARGET_SYSTEM above, in simplified form. (See also Cygwin.)
+# But aside from that, the Mingw-w64 nomenclature is rather messy.
+export CI_CC="$CI_TARGET_ARCH-w64-mingw32-gcc"
+export CI_AR="$CI_CC-ar"
+export CI_RANLIB="$CI_CC-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Windows
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/ci/targets/windows/ci_env.x86_64-windows-llvm.sh
+++ b/ci/targets/windows/ci_env.x86_64-windows-llvm.sh
@ -0,0 +1,18 @@
+# Copyright (c) 2023-2024 Cosmin Truta.
+#
+# Use, modification and distribution are subject to the MIT License.
+# Please see the accompanying file LICENSE_MIT.txt
+#
+# SPDX-License-Identifier: MIT
+
+export CI_TARGET_ARCH=x86_64
+export CI_TARGET_SYSTEM=windows
+
+export CI_CC="clang"
+export CI_AR="llvm-ar"
+export CI_RANLIB="llvm-ranlib"
+
+export CI_CMAKE_VARS="
+    -DCMAKE_SYSTEM_NAME=Windows
+    -DCMAKE_SYSTEM_PROCESSOR=$CI_TARGET_ARCH
+"
--- a/42
+++ b/42
@ -1,9 +1,9 @@
 #! /bin/sh
 # Wrapper for compilers which do not understand '-c -o'.

-scriptversion=2018-03-07.03; # UTC
+scriptversion=2025-06-18.21; # UTC

-# Copyright (C) 1999-2021 Free Software Foundation, Inc.
+# Copyright (C) 1999-2025 Free Software Foundation, Inc.
 # Written by Tom Tromey <tromey@cygnus.com>.
 #
 # This program is free software; you can redistribute it and/or modify
@ -37,11 +37,11 @@ IFS=" ""	$nl"

 file_conv=

-# func_file_conv build_file lazy
+# func_file_conv build_file unneeded_conversions
 # Convert a $build file to $host form and store it in $file
 # Currently only supports Windows hosts. If the determined conversion
-# type is listed in (the comma separated) LAZY, no conversion will
-# take place.
+# type is listed in (the comma separated) UNNEEDED_CONVERSIONS, no
+# conversion will take place.
 func_file_conv ()
 {
  file=$1
@ -51,9 +51,20 @@ func_file_conv ()
 	# lazily determine how to convert abs files
 	case `uname -s` in
 	  MINGW*)
-	    file_conv=mingw
+	    if test -n "$MSYSTEM" && (cygpath --version) >/dev/null 2>&1; then
+	      # MSYS2 environment.
+	      file_conv=cygwin
+	    else
+	      # Original MinGW environment.
+	      file_conv=mingw
+	    fi
 	    ;;
-	  CYGWIN* | MSYS*)
+	  MSYS*)
+	    # Old MSYS environment, or MSYS2 with 32-bit MSYS2 shell.
+	    file_conv=cygwin
+	    ;;
+	  CYGWIN*)
+	    # Cygwin environment.
 	    file_conv=cygwin
 	    ;;
 	  *)
@ -63,12 +74,14 @@ func_file_conv ()
      fi
      case $file_conv/,$2, in
 	*,$file_conv,*)
+	  # This is the optimization mentioned above:
+	  # If UNNEEDED_CONVERSIONS contains $file_conv, don't convert.
 	  ;;
 	mingw/*)
 	  file=`cmd //C echo "$file " | sed -e 's/"\(.*\) " *$/\1/'`
 	  ;;
-	cygwin/* | msys/*)
-	  file=`cygpath -m "$file" || echo "$file"`
+	cygwin/*)
+	  file=`cygpath -w "$file" || echo "$file"`
 	  ;;
 	wine/*)
 	  file=`winepath -w "$file" || echo "$file"`
@ -143,7 +156,7 @@ func_cl_wrapper ()
 	  # configure might choose to run compile as 'compile cc -o foo foo.c'.
 	  eat=1
 	  case $2 in
-	    *.o | *.[oO][bB][jJ])
+	    *.o | *.lo | *.[oO][bB][jJ])
 	      func_file_conv "$2"
 	      set x "$@" -Fo"$file"
 	      shift
@ -248,14 +261,17 @@ If you are trying to build a whole package this is not the
 right script to run: please start by reading the file 'INSTALL'.

 Report bugs to <bug-automake@gnu.org>.
+GNU Automake home page: <https://www.gnu.org/software/automake/>.
+General help using GNU software: <https://www.gnu.org/gethelp/>.
 EOF
    exit $?
    ;;
  -v | --v*)
-    echo "compile $scriptversion"
+    echo "compile (GNU Automake) $scriptversion"
    exit $?
    ;;
  cl | *[/\\]cl | cl.exe | *[/\\]cl.exe | \
+  clang-cl | *[/\\]clang-cl | clang-cl.exe | *[/\\]clang-cl.exe | \
  icl | *[/\\]icl | icl.exe | *[/\\]icl.exe )
    func_cl_wrapper "$@"      # Doesn't return...
    ;;
@ -340,9 +356,9 @@ exit $ret
 # Local Variables:
 # mode: shell-script
 # sh-indentation: 2
-# eval: (add-hook 'before-save-hook 'time-stamp)
+# eval: (add-hook 'before-save-hook 'time-stamp nil t)
 # time-stamp-start: "scriptversion="
-# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-format: "%Y-%02m-%02d.%02H"
 # time-stamp-time-zone: "UTC0"
 # time-stamp-end: "; # UTC"
 # End:
--- a/config.guess
+++ b/config.guess
@ -1,10 +1,10 @@
 #! /bin/sh
 # Attempt to guess a canonical system name.
-#   Copyright 1992-2023 Free Software Foundation, Inc.
+#   Copyright 1992-2024 Free Software Foundation, Inc.

 # shellcheck disable=SC2006,SC2268 # see below for rationale

-timestamp='2023-08-22'
+timestamp='2024-07-27'

 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@ -60,7 +60,7 @@ version="\
 GNU config.guess ($timestamp)

 Originally written by Per Bothner.
-Copyright 1992-2023 Free Software Foundation, Inc.
+Copyright 1992-2024 Free Software Foundation, Inc.

 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE."
@ -123,7 +123,7 @@ set_cc_for_build() {
    dummy=$tmp/dummy
    case ${CC_FOR_BUILD-},${HOST_CC-},${CC-} in
 	,,)    echo "int x;" > "$dummy.c"
-	       for driver in cc gcc c89 c99 ; do
+	       for driver in cc gcc c17 c99 c89 ; do
 		   if ($driver -c -o "$dummy.o" "$dummy.c") >/dev/null 2>&1 ; then
 		       CC_FOR_BUILD=$driver
 		       break
@ -165,6 +165,8 @@ Linux|GNU|GNU/*)
 	LIBC=dietlibc
 	#elif defined(__GLIBC__)
 	LIBC=gnu
+	#elif defined(__LLVM_LIBC__)
+	LIBC=llvm
 	#else
 	#include <stdarg.h>
 	/* First heuristic to detect musl libc.  */
@ -632,7 +634,8 @@ EOF
 		sed 's/^		//' << EOF > "$dummy.c"
 		#include <sys/systemcfg.h>

-		main()
+		int
+		main ()
 			{
 			if (!__power_pc())
 				exit(1);
@ -716,7 +719,8 @@ EOF
 		#include <stdlib.h>
 		#include <unistd.h>

-		int main ()
+		int
+		main ()
 		{
 		#if defined(_SC_KERNEL_BITS)
 		    long bits = sysconf(_SC_KERNEL_BITS);
@ -1593,6 +1597,9 @@ EOF
    *:Unleashed:*:*)
 	GUESS=$UNAME_MACHINE-unknown-unleashed$UNAME_RELEASE
 	;;
+    *:Ironclad:*:*)
+	GUESS=$UNAME_MACHINE-unknown-ironclad
+	;;
 esac

 # Do we have a guess based on uname results?
@ -1616,6 +1623,7 @@ cat > "$dummy.c" <<EOF
 #endif
 #endif
 #endif
+int
 main ()
 {
 #if defined (sony)
--- a/config.h.in
+++ b/config.h.in
@ -108,6 +108,9 @@
 /* Enable POWERPC VSX optimizations */
 #undef PNG_POWERPC_VSX_OPT

+/* Enable RISCV RVV optimizations */
+#undef PNG_RISCV_RVV_OPT
+
 /* 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. */
--- a/config.sub
+++ b/config.sub
--- a/1841
+++ b/1841
--- a/configure.ac
+++ b/configure.ac
@ -25,7 +25,7 @@ AC_PREREQ([2.68])

 dnl Version number stuff here:

-AC_INIT([libpng],[1.6.43],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.51.git],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts/autoconf])

 # libpng does not follow GNU file name conventions (hence 'foreign')
@ -46,17 +46,17 @@ 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=1.6.43
+PNGLIB_VERSION=1.6.51.git
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=43
+PNGLIB_RELEASE=51

 dnl End of version number stuff

 AC_CONFIG_SRCDIR([pngget.c])
 AC_CONFIG_HEADERS([config.h])

-# Check for basic programs.
+# Check the basic programs.
 AC_LANG([C])
 AC_PROG_CC
 AM_PROG_AS
@ -343,6 +343,9 @@ AC_ARG_ENABLE([hardware-optimizations],
         enable_loongarch_lsx=no
         AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [0],
           [Disable LOONGARCH_LSX optimizations])
+         enable_riscv_rvv=no
+         AC_DEFINE([PNG_RISCV_RVV_OPT], [0],
+           [Disable RISC-V Vector optimizations])
         ;;
      *)
         # allow enabling hardware optimization on any system:
@ -375,6 +378,11 @@ AC_ARG_ENABLE([hardware-optimizations],
              AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [1],
                [Enable LOONGARCH_LSX optimizations])
              ;;
+            riscv64)
+              enable_riscv_rvv=yes
+              AC_DEFINE([PNG_RISCV_RVV_OPT], [2],
+                [Enable RISC-V Vector optimizations])
+              ;;
         esac
         ;;
   esac])
@ -661,6 +669,76 @@ AM_CONDITIONAL([PNG_LOONGARCH_LSX],
      *)    test "$enable_loongarch_lsx" != '' ;;
    esac])

+# RISC-V
+# ======
+#
+# RISC-V Vector support.
+
+AC_ARG_ENABLE([riscv-rvv],
+AS_HELP_STRING([[[--enable-riscv-rvv]]],
+      [Enable RISC-V Vector optimizations: =no/off, check, api, yes/on:]
+      [no/off: disable the optimizations; check: use internal checking code]
+      [api: disable by default, enable by a call to png_set_option]
+      [yes/on: turn on. If not specified: determined by the compiler.]),
+   [case "$enableval" in
+      no|off)
+         # disable the default enabling on __riscv systems:
+         AC_DEFINE([PNG_RISCV_RVV_OPT], [0],
+                   [Disable RISC-V Vector optimizations])
+         # Prevent inclusion of the platform-specific files below:
+         enable_riscv_rvv=no ;;
+      yes|on)
+         AC_DEFINE([PNG_RISCV_RVV_OPT], [2],
+                   [Enable RISC-V Vector optimizations])
+         AC_MSG_WARN([--enable-riscv-rvv:]
+            [if you want the optimizations pass e.g. '-march=rv64gv1p0' to the compiler.]);;
+      *)
+         AC_MSG_ERROR([--enable-riscv-rvv=${enable_riscv_rvv}: invalid value])
+   esac])
+
+if test "$enable_riscv_rvv" != "no" &&
+   case "$host_cpu" in
+      riscv64) : ;;
+      *)    test "$enable_riscv_rvv" != '' ;;
+   esac
+then
+   compiler_support_riscv_rvv=no
+   AC_MSG_CHECKING(whether to use RISC-V RVV intrinsics)
+
+   AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+#include <riscv_vector.h>
+#include <asm/hwcap.h>
+#ifndef COMPAT_HWCAP_ISA_V /* added in linux-6.5 */
+#error "COMPAT_HWCAP_ISA_V is not available"
+#endif
+int main() {
+   const float src[] = { 0.0f, 0.0f, 0.0f, 0.0f };
+   uint64_t ptr[2] = {0x0908060504020100, 0xFFFFFFFF0E0D0C0A};
+   vuint8m1_t a = __riscv_vreinterpret_v_u64m1_u8m1(__riscv_vle64_v_u64m1(ptr, 2));
+   vfloat32m1_t val = __riscv_vle32_v_f32m1((const float*)(src), 4);
+   return (int)__riscv_vfmv_f_s_f32m1_f32(val);
+}]])],compiler_support_riscv_rvv=yes)
+   AC_MSG_RESULT($compiler_support_riscv_rvv)
+   if test "$compiler_support_riscv_rvv" = "yes"; then
+      AC_DEFINE([PNG_RISCV_RVV_OPT], [1],
+                [Enable RISCV RVV optimizations])
+   else
+      AC_MSG_WARN([Compiler does not support riscv rvv.])
+   fi
+fi
+
+# Add RISC-V-specific files to all builds where $host_cpu is riscv ('riscv64')
+# or where RISC-V optimizations were explicitly requested (this allows a fallback
+# if a future host CPU does not match 'riscv64')
+
+AM_CONDITIONAL([PNG_RISCV_RVV],
+   [test "$enable_riscv_rvv" != "no" &&
+    test "$compiler_support_riscv_rvv" = "yes" &&
+    case "$host_cpu" in
+      riscv64) : ;;
+      *)    test "$compiler_support_riscv_rvv" != '' ;;
+    esac])
+
 AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])

 # Config files, substituting as above
--- a/contrib/.editorconfig
+++ b/contrib/.editorconfig
@ -3,5 +3,7 @@
 root = false

 [*.[ch]]
+indent_size = unset
+indent_style = unset
 max_doc_length = unset
 max_line_length = unset
--- a/contrib/README.txt
+++ b/contrib/README.txt
@ -1,3 +1,5 @@
+External contributions to libpng
+--------------------------------

 This "contrib" directory contains contributions which are not necessarily under
 the libpng license, although all are open source.  They are not part of
--- a/contrib/conftest/fixed.dfa
+++ b/contrib/conftest/fixed.dfa
@ -0,0 +1,15 @@
+# fixed.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2025
+# Usage rights:
+#  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.
+#
+# Test the standard libpng configuration without floating point (the internal
+# fixed point implementations are used instead).
+#
+option FLOATING_ARITHMETIC off
+option FLOATING_POINT off
--- a/contrib/conftest/float-fixed.dfa
+++ b/contrib/conftest/float-fixed.dfa
@ -0,0 +1,14 @@
+# fixed-float.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2025
+# Usage rights:
+#  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.
+#
+# Test the standard libpng configuration with the fixed point internal
+# implementation in place of the default floating point
+#
+option FLOATING_ARITHMETIC off
--- a/contrib/conftest/nocompile-limits.dfa
+++ b/contrib/conftest/nocompile-limits.dfa
@ -0,0 +1,21 @@
+# nolimits.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2025
+#
+# Usage rights:
+#  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.
+#
+# Build libpng without any limits and without run-time settable limits.  Turning
+# USER_LIMITS off reduces libpng code size by allowing compile-time elimination
+# of some checking code.
+#
+option USER_LIMITS off
+
+@# define PNG_USER_WIDTH_MAX PNG_UINT_31_MAX
+@# define PNG_USER_HEIGHT_MAX PNG_UINT_31_MAX
+@# define PNG_USER_CHUNK_CACHE_MAX 0
+@# define PNG_USER_CHUNK_MALLOC_MAX 0
--- a/contrib/conftest/nolimits.dfa
+++ b/contrib/conftest/nolimits.dfa
@ -0,0 +1,19 @@
+# nolimits.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2025
+#
+# Usage rights:
+#  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.
+#
+# Build libpng without any limits.  With these settigs run-time limits are still
+# possible.
+#
+@# define PNG_USER_WIDTH_MAX PNG_UINT_31_MAX
+@# define PNG_USER_HEIGHT_MAX PNG_UINT_31_MAX
+@# define PNG_USER_CHUNK_CACHE_MAX 0
+@# define PNG_USER_CHUNK_MALLOC_MAX 0
+
--- a/contrib/conftest/read-full.dfa
+++ b/contrib/conftest/read-full.dfa
@ -0,0 +1,13 @@
+# read-full.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2025
+# Usage rights:
+#  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.
+#
+# Build libpng with no write support and full read support.
+#
+option WRITE off
--- a/contrib/conftest/write-full.dfa
+++ b/contrib/conftest/write-full.dfa
@ -0,0 +1,13 @@
+# write-full.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2025
+# Usage rights:
+#  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.
+#
+# Build libpng with no read support and full write support.
+#
+option READ off
--- a/contrib/examples/.clang-format
+++ b/contrib/examples/.clang-format
@ -0,0 +1,143 @@
+---
+Language: Cpp
+AccessModifierOffset: -3
+AlignAfterOpenBracket: Align
+AlignArrayOfStructures: None
+AlignConsecutiveAssignments:
+  Enabled: false
+AlignConsecutiveBitFields:
+  Enabled: false
+AlignConsecutiveDeclarations:
+  Enabled: false
+AlignConsecutiveMacros:
+  Enabled: false
+AlignConsecutiveShortCaseStatements:
+  Enabled: false
+AlignEscapedNewlines: DontAlign
+AlignOperands: false
+AlignTrailingComments:
+  Kind: Never
+  OverEmptyLines: 0
+AllowAllArgumentsOnNextLine: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowBreakBeforeNoexceptSpecifier: Never
+AllowShortBlocksOnASingleLine: Never
+AllowShortCaseExpressionOnASingleLine: true
+AllowShortCaseLabelsOnASingleLine: true
+AllowShortCompoundRequirementOnASingleLine: true
+AllowShortEnumsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: None
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLambdasOnASingleLine: All
+AllowShortLoopsOnASingleLine: false
+AllowShortNamespacesOnASingleLine: false
+AlwaysBreakBeforeMultilineStrings: false
+BinPackArguments: true
+BinPackParameters: BinPack
+BitFieldColonSpacing: Both
+BraceWrapping:
+  AfterCaseLabel: true
+  AfterClass: true
+  AfterControlStatement: Always
+  AfterEnum: true
+  AfterExternBlock: false
+  AfterFunction: true
+  AfterNamespace: false
+  AfterObjCDeclaration: true
+  AfterStruct: true
+  AfterUnion: true
+  BeforeCatch: true
+  BeforeElse: true
+  BeforeLambdaBody: false
+  BeforeWhile: false
+  IndentBraces: false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakAdjacentStringLiterals: true
+BreakAfterAttributes: Leave
+BreakAfterJavaFieldAnnotations: false
+BreakAfterReturnType: TopLevel
+BreakArrays: true
+BreakBeforeBinaryOperators: None
+BreakBeforeConceptDeclarations: Always
+BreakBeforeBraces: Custom
+BreakBeforeTernaryOperators: false
+BreakStringLiterals: false
+BreakTemplateDeclarations: MultiLine
+ColumnLimit: 79
+ContinuationIndentWidth: 3
+DerivePointerAlignment: true
+EmptyLineAfterAccessModifier: Never
+EmptyLineBeforeAccessModifier: LogicalBlock
+FixNamespaceComments: true
+IncludeBlocks: Preserve
+IndentAccessModifiers: false
+IndentCaseBlocks: true
+IndentCaseLabels: true
+IndentExportBlock: true
+IndentExternBlock: AfterExternBlock
+IndentGotoLabels: false
+IndentPPDirectives: None
+IndentRequiresClause: true
+IndentWidth: 3
+IndentWrappedFunctionNames: false
+KeepEmptyLines:
+  AtEndOfFile: false
+  AtStartOfBlock: false
+  AtStartOfFile: false
+KeepFormFeed: false
+MaxEmptyLinesToKeep: 2
+NamespaceIndentation: None
+PackConstructorInitializers: Never
+PointerAlignment: Left
+QualifierAlignment: Custom
+QualifierOrder: [static, inline, constexpr, const, volatile, restrict, type]
+ReferenceAlignment: Pointer
+ReflowComments: Never
+RequiresClausePosition: OwnLine
+RequiresExpressionIndentation: OuterScope
+SortIncludes: false
+SortUsingDeclarations: LexicographicNumeric
+SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: true
+SpaceAroundPointerQualifiers: Default
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCaseColon: false
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeJsonColon: false
+SpaceBeforeParens: ControlStatements
+SpaceBeforeParensOptions:
+  AfterControlStatements: true
+  AfterFunctionDefinitionName: false
+  AfterFunctionDeclarationName: false
+  AfterOverloadedOperator: false
+  AfterPlacementOperator: true
+  AfterRequiresInClause: false
+  AfterRequiresInExpression: false
+  BeforeNonEmptyParentheses: false
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceBeforeSquareBrackets: false
+SpaceInEmptyBlock: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: Never
+SpacesInContainerLiterals: true
+SpacesInLineCommentPrefix:
+  Minimum: 1
+  Maximum: -1
+SpacesInParens: Never
+SpacesInParensOptions:
+  ExceptDoubleParentheses: false
+  InCStyleCasts: false
+  InConditionalStatements: false
+  InEmptyParentheses: false
+  Other: false
+SpacesInSquareBrackets: false
+Standard: Latest
+TabWidth: 8
+UseTab: Never
+WrapNamespaceBodyWithEmptyLines: Leave
+...
--- a/contrib/examples/README.txt
+++ b/contrib/examples/README.txt
@ -1,4 +1,3 @@
-
 This directory (contrib/examples) contains examples of libpng usage.

 NO COPYRIGHT RIGHTS ARE CLAIMED TO ANY OF THE FILES IN THIS DIRECTORY.
--- a/contrib/examples/iccfrompng.c
+++ b/contrib/examples/iccfrompng.c
@ -26,8 +26,9 @@

 #include <png.h>

-#if defined(PNG_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED) && \
-    defined (PNG_iCCP_SUPPORTED)
+#if !defined(PNG_iCCP_SUPPORTED) || !defined(PNG_READ_SUPPORTED)
+#error This program requires libpng supporting the iCCP chunk and the read API
+#endif


 static int verbose = 1;
@ -36,7 +37,8 @@ static png_byte no_profile[] = "no profile";
 static png_bytep
 extract(FILE *fp, png_uint_32 *proflen)
 {
-   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+   png_structp png_ptr =
+      png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
   png_infop info_ptr = NULL;
   png_bytep result = NULL;

@ -69,7 +71,7 @@ extract(FILE *fp, png_uint_32 *proflen)
      png_bytep profile;

      if (png_get_iCCP(png_ptr, info_ptr, &name, &compression_type, &profile,
-         proflen) & PNG_INFO_iCCP)
+                       proflen) & PNG_INFO_iCCP)
      {
         result = malloc(*proflen);
         if (result != NULL)
@ -107,7 +109,7 @@ extract_one_file(const char *filename)
            const char *ep = strrchr(filename, '.');

            if (ep != NULL)
-               len = ep-filename;
+               len = ep - filename;

            else
               len = strlen(filename);
@ -119,14 +121,14 @@ extract_one_file(const char *filename)
            FILE *of;

            memcpy(output, filename, len);
-            strcpy(output+len, ".icc");
+            strcpy(output + len, ".icc");

            of = fopen(output, "wb");
            if (of != NULL)
            {
               if (fwrite(profile, proflen, 1, of) == 1 &&
-                  fflush(of) == 0 &&
-                  fclose(of) == 0)
+                   fflush(of) == 0 &&
+                   fclose(of) == 0)
               {
                  if (verbose)
                     printf("%s -> %s\n", filename, output);
@ -161,6 +163,9 @@ extract_one_file(const char *filename)
   else
      fprintf(stderr, "%s: could not open file\n", filename);

+   if (fp != NULL)
+      fclose(fp);
+
   return result;
 }

@ -170,7 +175,7 @@ main(int argc, char **argv)
   int i;
   int extracted = 0;

-   for (i=1; i<argc; ++i)
+   for (i = 1; i < argc; ++i)
   {
      if (strcmp(argv[i], "-q") == 0)
         verbose = 0;
@ -182,4 +187,3 @@ main(int argc, char **argv)
   /* Exit code is true if any extract succeeds */
   return extracted == 0;
 }
-#endif /* READ && STDIO && iCCP */
--- a/contrib/examples/pngpixel.c
+++ b/contrib/examples/pngpixel.c
@ -15,8 +15,8 @@
 * images.  Normally you would call png_set_interlace_handling() to have libpng
 * deal with the interlace for you, but that obliges you to buffer half of the
 * image to assemble the interlaced rows.  In this code
- * png_set_interlace_handling() is not called and, instead, the code handles the
- * interlace passes directly looking for the required pixel.
+ * png_set_interlace_handling() is not called and, instead, the code handles
+ * the interlace passes directly looking for the required pixel.
 */
 #include <stdlib.h>
 #include <stdio.h>
@ -27,34 +27,37 @@
 */
 #include "../../png.h"

-#if defined(PNG_READ_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_SUPPORTED)
+#if !defined(PNG_READ_SUPPORTED) || !defined(PNG_SEQUENTIAL_READ_SUPPORTED)
+#error This program requires libpng supporting the read and sequential read API
+#endif
+

 /* Return component 'c' of pixel 'x' from the given row. */
 static unsigned int
 component(png_const_bytep row, png_uint_32 x, unsigned int c,
-   unsigned int bit_depth, unsigned int channels)
+          unsigned int bit_depth, unsigned int channels)
 {
-   /* PNG images can be up to 2^31 pixels wide, but this means they can be up to
-    * 2^37 bits wide (for a 64-bit pixel - the largest possible) and hence 2^34
-    * bytes wide.  Since the row fitted into memory, however, the following must
+   /* PNG images can be up to 2^31 pixels wide, which means they can be up to
+    * 2^37 bits wide (for a 64-bit pixel - the largest possible) and hence
+    * 2^34 bytes wide.  Since the row fitted into memory, the following must
    * work:
    */
   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)(((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;

   /* PNG pixels are packed into bytes to put the first pixel in the highest
-    * bits of the byte and into two bytes for 16-bit values with the high 8 bits
-    * first, so:
+    * bits of the byte, and into two bytes for 16-bit values with the high
+    * 8 bits first, so:
    */
   switch (bit_depth)
   {
-      case 1: return (row[0] >> (7-bit_offset_lo)) & 0x01;
-      case 2: return (row[0] >> (6-bit_offset_lo)) & 0x03;
-      case 4: return (row[0] >> (4-bit_offset_lo)) & 0x0f;
+      case 1: return (row[0] >> (7 - bit_offset_lo)) & 0x01;
+      case 2: return (row[0] >> (6 - bit_offset_lo)) & 0x03;
+      case 4: return (row[0] >> (4 - bit_offset_lo)) & 0x0f;
      case 8: return row[0];
      case 16: return (row[0] << 8) + row[1];
      default:
@ -71,7 +74,7 @@ component(png_const_bytep row, png_uint_32 x, unsigned int c,
 */
 static void
 print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
-   png_uint_32 x)
+            png_uint_32 x)
 {
   unsigned int bit_depth = png_get_bit_depth(png_ptr, info_ptr);

@ -92,22 +95,24 @@ print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
            int num_palette = 0;

            if ((png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette) &
-               PNG_INFO_PLTE) && num_palette > 0 && palette != NULL)
+                 PNG_INFO_PLTE) &&
+                (num_palette > 0) &&
+                (palette != NULL))
            {
               png_bytep trans_alpha = NULL;
               int num_trans = 0;
               if ((png_get_tRNS(png_ptr, info_ptr, &trans_alpha, &num_trans,
-                  NULL) & PNG_INFO_tRNS) && num_trans > 0 &&
-                  trans_alpha != NULL)
+                                 NULL) & PNG_INFO_tRNS) &&
+                   (num_trans > 0) &&
+                   (trans_alpha != NULL))
                  printf("INDEXED %u = %d %d %d %d\n", index,
-                     palette[index].red, palette[index].green,
-                     palette[index].blue,
-                     index < num_trans ? trans_alpha[index] : 255);
+                         palette[index].red, palette[index].green,
+                         palette[index].blue,
+                         index < num_trans ? trans_alpha[index] : 255);

               else /* no transparency */
-                  printf("INDEXED %u = %d %d %d\n", index,
-                     palette[index].red, palette[index].green,
-                     palette[index].blue);
+                  printf("INDEXED %u = %d %d %d\n", index, palette[index].red,
+                         palette[index].green, palette[index].blue);
            }

            else
@ -117,20 +122,20 @@ print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,

      case PNG_COLOR_TYPE_RGB:
         printf("RGB %u %u %u\n", component(row, x, 0, bit_depth, 3),
-            component(row, x, 1, bit_depth, 3),
-            component(row, x, 2, bit_depth, 3));
+                component(row, x, 1, bit_depth, 3),
+                component(row, x, 2, bit_depth, 3));
         return;

      case PNG_COLOR_TYPE_GRAY_ALPHA:
         printf("GRAY+ALPHA %u %u\n", component(row, x, 0, bit_depth, 2),
-            component(row, x, 1, bit_depth, 2));
+                component(row, x, 1, bit_depth, 2));
         return;

      case PNG_COLOR_TYPE_RGB_ALPHA:
         printf("RGBA %u %u %u %u\n", component(row, x, 0, bit_depth, 4),
-            component(row, x, 1, bit_depth, 4),
-            component(row, x, 2, bit_depth, 4),
-            component(row, x, 3, bit_depth, 4));
+                component(row, x, 1, bit_depth, 4),
+                component(row, x, 2, bit_depth, 4),
+                component(row, x, 3, bit_depth, 4));
         return;

      default:
@ -138,7 +143,8 @@ print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
   }
 }

-int main(int argc, const char **argv)
+int
+main(int argc, const char **argv)
 {
   /* This program uses the default, <setjmp.h> based, libpng error handling
    * mechanism, therefore any local variable that exists before the call to
@ -146,7 +152,7 @@ int main(int argc, const char **argv)
    * be declared with 'volatile' to ensure that their values don't get
    * destroyed by longjmp:
    */
-   volatile int result = 1/*fail*/;
+   volatile int result = 1 /*fail*/;

   if (argc == 4)
   {
@ -163,8 +169,8 @@ int main(int argc, const char **argv)
          * writes error messages to stderr.  Creating the png_struct is a
          * little tricky; just copy the following code.
          */
-         png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
-            NULL, NULL, NULL);
+         png_structp png_ptr =
+            png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);

         if (png_ptr != NULL)
         {
@ -184,11 +190,11 @@ int main(int argc, const char **argv)
                     compression_method, filter_method;
                  png_bytep row_tmp;

-                  /* Now associate the recently opened (FILE*) with the default
-                   * libpng initialization functions.  Sometimes libpng is
-                   * compiled without stdio support (it can be difficult to do
-                   * in some environments); in that case you will have to write
-                   * your own read callback to read data from the (FILE*).
+                  /* Now associate the recently opened FILE object with the
+                   * default libpng initialization functions.  Sometimes libpng
+                   * is compiled without stdio support (it can be difficult to
+                   * do in some environments); in that case you will have to
+                   * write your own read callback to read data from the stream.
                   */
                  png_init_io(png_ptr, f);

@ -202,21 +208,21 @@ int main(int argc, const char **argv)
                   * space.  In this case png_malloc is used - it will not
                   * return if memory isn't available.
                   */
-                  row = png_malloc(png_ptr, png_get_rowbytes(png_ptr,
-                     info_ptr));
+                  row =
+                     png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));

-                  /* To avoid the overhead of using a volatile auto copy row_tmp
+                  /* Avoid the overhead of using a volatile auto copy row_tmp
                   * to a local here - just use row for the png_free below.
                   */
                  row_tmp = row;

-                  /* All the information we need is in the header is returned by
-                   * png_get_IHDR, if this fails we can now use 'png_error' to
+                  /* All the information we need is in the header returned by
+                   * png_get_IHDR.  If this fails, we can use 'png_error' to
                   * signal the error and return control to the setjmp above.
                   */
                  if (png_get_IHDR(png_ptr, info_ptr, &width, &height,
-                     &bit_depth, &color_type, &interlace_method,
-                     &compression_method, &filter_method))
+                                   &bit_depth, &color_type, &interlace_method,
+                                   &compression_method, &filter_method))
                  {
                     int passes, pass;

@ -242,7 +248,7 @@ int main(int argc, const char **argv)
                     /* Now read the pixels, pass-by-pass, row-by-row: */
                     png_start_read_image(png_ptr);

-                     for (pass=0; pass<passes; ++pass)
+                     for (pass = 0; pass < passes; ++pass)
                     {
                        png_uint_32 ystart, xstart, ystep, xstep;
                        png_uint_32 py;
@ -299,19 +305,27 @@ int main(int argc, const char **argv)
                            * are, of course, much better ways of doing this
                            * than using a for loop:
                            */
-                           if (y == py) for (px = xstart, ppx = 0;
-                              px < width; px += xstep, ++ppx) if (x == px)
+                           if (y == py)
                           {
-                              /* 'ppx' is the index of the pixel in the row
-                               * buffer.
-                               */
-                              print_pixel(png_ptr, info_ptr, row_tmp, ppx);
+                              for (px = xstart, ppx = 0;
+                                   px < width;
+                                   px += xstep, ++ppx)
+                              {
+                                 if (x == px)
+                                 {
+                                    /* 'ppx' is the index of the pixel in the
+                                     * row buffer.
+                                     */
+                                    print_pixel(png_ptr, info_ptr, row_tmp,
+                                                ppx);

-                              /* Now terminate the loops early - we have
-                               * found and handled the required data.
-                               */
-                              goto pass_loop_end;
-                           } /* x loop */
+                                    /* Now terminate the loops early - we have
+                                     * found and handled the required data.
+                                     */
+                                    goto pass_loop_end;
+                                 } /* x loop */
+                              }
+                           }
                        } /* y loop */
                     } /* pass loop */

@ -323,7 +337,6 @@ int main(int argc, const char **argv)

                  else
                     png_error(png_ptr, "pngpixel: png_get_IHDR failed");
-
               }

               else
@ -349,7 +362,8 @@ int main(int argc, const char **argv)
            }

            else
-               fprintf(stderr, "pngpixel: out of memory allocating png_info\n");
+               fprintf(stderr,
+                       "pngpixel: out of memory allocating png_info\n");

            png_destroy_read_struct(&png_ptr, NULL, NULL);
         }
@ -368,4 +382,3 @@ int main(int argc, const char **argv)

   return result;
 }
-#endif /* READ && SEQUENTIAL_READ */
--- a/contrib/examples/pngtopng.c
+++ b/contrib/examples/pngtopng.c
@ -8,8 +8,8 @@
 * Read a PNG and write it out in a fixed format, using the 'simplified API'
 * that was introduced in libpng-1.6.0.
 *
- * This sample code is just the code from the top of 'example.c' with some error
- * handling added.  See example.c for more comments.
+ * This sample code is just the code from 'example.c' with some error handling
+ * added.  See example.c in the top-level libpng directory for more comments.
 */
 #include <stddef.h>
 #include <stdlib.h>
@ -20,10 +20,15 @@
 * ensure the code picks up the local libpng implementation:
 */
 #include "../../png.h"
-#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && \
-    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)

-int main(int argc, const char **argv)
+#if !defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
+    !defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+#error This program requires libpng supporting the simplified read/write API
+#endif
+
+
+int
+main(int argc, const char **argv)
 {
   int result = 1;

@ -48,22 +53,22 @@ int main(int argc, const char **argv)

         if (buffer != NULL)
         {
-            if (png_image_finish_read(&image, NULL/*background*/, buffer,
-               0/*row_stride*/, NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP */))
+            if (png_image_finish_read(&image, NULL /*background*/, buffer,
+                                      0 /*row_stride*/, NULL /*colormap */))
            {
-               if (png_image_write_to_file(&image, argv[2],
-                  0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
-                  NULL/*colormap*/))
+               if (png_image_write_to_file(
+                      &image, argv[2], 0 /*convert_to_8bit*/, buffer,
+                      0 /*row_stride*/, NULL /*colormap*/))
                  result = 0;

               else
                  fprintf(stderr, "pngtopng: write %s: %s\n", argv[2],
-                      image.message);
+                          image.message);
            }

            else
               fprintf(stderr, "pngtopng: read %s: %s\n", argv[1],
-                   image.message);
+                       image.message);

            free(buffer);
         }
@ -71,7 +76,7 @@ int main(int argc, const char **argv)
         else
         {
            fprintf(stderr, "pngtopng: out of memory: %lu bytes\n",
-               (unsigned long)PNG_IMAGE_SIZE(image));
+                    (unsigned long)PNG_IMAGE_SIZE(image));

            /* This is the only place where a 'free' is required; libpng does
             * the cleanup on error and success, but in this case we couldn't
@ -93,4 +98,3 @@ int main(int argc, const char **argv)

   return result;
 }
-#endif /* READ && WRITE */
--- a/contrib/examples/simpleover.c
+++ b/contrib/examples/simpleover.c
@ -6,9 +6,9 @@
 * United States.
 *
 * Read several PNG files, which should have an alpha channel or transparency
- * information, and composite them together to produce one or more 16-bit linear
- * RGBA intermediates.  This involves doing the correct 'over' composition to
- * combine the alpha channels and corresponding data.
+ * information, and composite them together to produce one or more 16-bit
+ * linear RGBA intermediates.  This involves doing the 'over' compositing
+ * operation to combine the alpha channels and corresponding data.
 *
 * Finally read an output (background) PNG using the 24-bit RGB format (the
 * PNG will be composited on green (#00ff00) by default if it has an alpha
@ -28,8 +28,8 @@
 * correctly.  Apart from the libpng Simplified API the only work done in here
 * is to combine multiple input PNG images into a single sprite; this involves
 * a Porter-Duff 'over' operation and the input PNG images may, as a result,
- * be regarded as being layered one on top of the other with the first (leftmost
- * on the command line) being at the bottom and the last on the top.
+ * be regarded as being layered one on top of the other with the first
+ * (leftmost on the command line) being at the bottom and the last on the top.
 */
 #include <stddef.h>
 #include <stdlib.h>
@ -44,54 +44,61 @@
 */
 #include "../../png.h"

-#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+#if !defined(PNG_SIMPLIFIED_READ_SUPPORTED)
+#error This program requires libpng supporting the simplified read API
+#endif

 #define sprite_name_chars 15
-struct sprite {
-   FILE         *file;
-   png_uint_16p  buffer;
-   unsigned int  width;
-   unsigned int  height;
-   char          name[sprite_name_chars+1];
+struct sprite
+{
+   FILE *file;
+   png_uint_16p buffer;
+   unsigned int width;
+   unsigned int height;
+   char name[sprite_name_chars + 1];
 };

 #if 0 /* div by 65535 test program */
 #include <math.h>
 #include <stdio.h>

-int main(void) {
+int
+main(void)
+{
   double err = 0;
   unsigned int xerr = 0;
   unsigned int r = 32769;
+   unsigned int x = 0;
+
+   do
   {
-      unsigned int x = 0;
+      unsigned int t = x + (x >> 16) /*+ (x >> 31)*/ + r;
+      double v = x, errtest;

-      do {
-         unsigned int t = x + (x >> 16) /*+ (x >> 31)*/ + r;
-         double v = x, errtest;
+      if (t < x)
+      {
+         fprintf(stderr, "overflow: %u+%u -> %u\n", x, r, t);
+         return 1;
+      }

-         if (t < x) {
-            fprintf(stderr, "overflow: %u+%u -> %u\n", x, r, t);
-            return 1;
+      v /= 65535;
+      errtest = v;
+      t >>= 16;
+      errtest -= t;
+
+      if (errtest > err)
+      {
+         err = errtest;
+         xerr = x;
+
+         if (errtest >= .5)
+         {
+            fprintf(stderr, "error: %u/65535 = %f, not %u, error %f\n",
+                    x, v, t, errtest);
+            return 0;
         }
-
-         v /= 65535;
-         errtest = v;
-         t >>= 16;
-         errtest -= t;
-
-         if (errtest > err) {
-            err = errtest;
-            xerr = x;
-
-            if (errtest >= .5) {
-               fprintf(stderr, "error: %u/65535 = %f, not %u, error %f\n",
-                     x, v, t, errtest);
-               return 0;
-            }
-         }
-      } while (++x <= 65535U*65535U);
-   }
+      }
+   } while (++x <= 65535U * 65535U);

   printf("error %f @ %u\n", err, xerr);

@ -101,7 +108,7 @@ int main(void) {

 static void
 sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
-   png_imagep image, const png_uint_16 *buffer)
+          png_imagep image, const png_uint_16 *buffer)
 {
   /* This is where the Porter-Duff 'Over' operator is evaluated; change this
    * code to change the operator (this could be parameterized).  Any other
@ -112,8 +119,8 @@ sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
   /* Check for an x or y offset that pushes any part of the image beyond the
    * right or bottom of the sprite:
    */
-   if ((y_offset < 0 || (unsigned)/*SAFE*/y_offset < sprite->height) &&
-       (x_offset < 0 || (unsigned)/*SAFE*/x_offset < sprite->width))
+   if ((y_offset < 0 || /*SAFE*/ (unsigned)y_offset < sprite->height) &&
+       (x_offset < 0 || /*SAFE*/ (unsigned)x_offset < sprite->width))
   {
      unsigned int y = 0;

@ -130,7 +137,7 @@ sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
         do
         {
            /* In and out are RGBA values, so: */
-            const png_uint_16 *in_pixel = buffer + (y * image->width + x)*4;
+            const png_uint_16 *in_pixel = buffer + (y * image->width + x) * 4;
            png_uint_32 in_alpha = in_pixel[3];

            /* This is the optimized Porter-Duff 'Over' operation, when the
@ -139,10 +146,10 @@ sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
            if (in_alpha > 0)
            {
               png_uint_16 *out_pixel = sprite->buffer +
-                  ((y+y_offset) * sprite->width + (x+x_offset))*4;
+                  ((y + y_offset) * sprite->width + (x + x_offset)) * 4;

               /* This is the weight to apply to the output: */
-               in_alpha = 65535-in_alpha;
+               in_alpha = 65535 - in_alpha;

               if (in_alpha > 0)
               {
@ -159,9 +166,9 @@ sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
                   */
                  png_uint_32 tmp;

-#                 define compose(c)\
-                     tmp = out_pixel[c] * in_alpha;\
-                     tmp = (tmp + (tmp >> 16) + 32769) >> 16;\
+#                 define compose(c) \
+                     tmp = out_pixel[c] * in_alpha; \
+                     tmp = (tmp + (tmp >> 16) + 32769) >> 16; \
                     out_pixel[c] = tmp + in_pixel[c]

                  /* The following is very vectorizable... */
@ -172,15 +179,15 @@ sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
               }

               else
-                  out_pixel[0] = in_pixel[0],
-                  out_pixel[1] = in_pixel[1],
-                  out_pixel[2] = in_pixel[2],
+               {
+                  out_pixel[0] = in_pixel[0];
+                  out_pixel[1] = in_pixel[1];
+                  out_pixel[2] = in_pixel[2];
                  out_pixel[3] = in_pixel[3];
+               }
            }
-         }
-         while (++x < image->width);
-      }
-      while (++y < image->height);
+         } while (++x < image->width);
+      } while (++y < image->height);
   }
 }

@ -224,9 +231,8 @@ create_sprite(struct sprite *sprite, int *argc, const char ***argv)

            if (buffer != NULL)
            {
-               if (png_image_finish_read(&image, NULL/*background*/, buffer,
-                  0/*row_stride*/,
-                  NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP*/))
+               if (png_image_finish_read(&image, NULL /*background*/, buffer,
+                                         0 /*row_stride*/, NULL /*colormap*/))
               {
                  /* This is the place where the Porter-Duff 'Over' operator
                   * needs to be done by this code.  In fact, any image
@ -245,14 +251,14 @@ create_sprite(struct sprite *sprite, int *argc, const char ***argv)
               {
                  free(buffer);
                  fprintf(stderr, "simpleover: read %s: %s\n", (*argv)[0],
-                      image.message);
+                          image.message);
               }
            }

            else
            {
               fprintf(stderr, "simpleover: out of memory: %lu bytes\n",
-                  (unsigned long)PNG_IMAGE_SIZE(image));
+                       (unsigned long)PNG_IMAGE_SIZE(image));

               /* png_image_free must be called if we abort the Simplified API
                * read because of a problem detected in this code.  If problems
@ -290,8 +296,9 @@ create_sprite(struct sprite *sprite, int *argc, const char ***argv)
      save.flags = PNG_IMAGE_FLAG_FAST;
      save.colormap_entries = 0;

-      if (png_image_write_to_stdio(&save, sprite->file, 1/*convert_to_8_bit*/,
-          sprite->buffer, 0/*row_stride*/, NULL/*colormap*/))
+      if (png_image_write_to_stdio(&save, sprite->file, 1 /*convert_to_8_bit*/,
+                                   sprite->buffer, 0 /*row_stride*/,
+                                   NULL /*colormap*/))
      {
         /* Success; the buffer is no longer needed: */
         free(sprite->buffer);
@ -301,19 +308,20 @@ create_sprite(struct sprite *sprite, int *argc, const char ***argv)

      else
         fprintf(stderr, "simpleover: write sprite %s: %s\n", sprite->name,
-            save.message);
+                 save.message);
   }

   else
-      fprintf(stderr, "simpleover: sprite %s: could not allocate tmpfile: %s\n",
-         sprite->name, strerror(errno));
+      fprintf(stderr,
+              "simpleover: sprite %s: could not allocate tmpfile: %s\n",
+              sprite->name, strerror(errno));

   return 0; /* fail */
 }

 static int
 add_sprite(png_imagep output, png_bytep out_buf, struct sprite *sprite,
-   int *argc, const char ***argv)
+           int *argc, const char ***argv)
 {
   /* Given a --add argument naming this sprite, perform the operations listed
    * in the following arguments.  The arguments are expected to have the form
@ -334,13 +342,13 @@ add_sprite(png_imagep output, png_bytep out_buf, struct sprite *sprite,
          * will fit.
          */
         if (x < 0 || y < 0 ||
-             (unsigned)/*SAFE*/x >= output->width ||
-             (unsigned)/*SAFE*/y >= output->height ||
-             sprite->width > output->width-x ||
-             sprite->height > output->height-y)
+             /*SAFE*/ (unsigned)x >= output->width ||
+             /*SAFE*/ (unsigned)y >= output->height ||
+             sprite->width > output->width - x ||
+             sprite->height > output->height - y)
         {
            fprintf(stderr, "simpleover: sprite %s @ (%d,%d) outside image\n",
-               sprite->name, x, y);
+                    sprite->name, x, y);
            /* Could just skip this, but for the moment it is an error */
            return 0; /* error */
         }
@ -359,10 +367,10 @@ add_sprite(png_imagep output, png_bytep out_buf, struct sprite *sprite,
            {
               in.format = PNG_FORMAT_RGB; /* force compose */

-               if (png_image_finish_read(&in, NULL/*background*/,
-                  out_buf + (y*output->width + x)*3/*RGB*/,
-                  output->width*3/*row_stride*/,
-                  NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP*/))
+               if (png_image_finish_read(
+                      &in, NULL /*background*/,
+                      out_buf + (y * output->width + x) * 3 /*RGB*/,
+                      output->width * 3 /*row_stride*/, NULL /*colormap*/))
               {
                  ++*argv, --*argc;
                  continue;
@ -371,7 +379,7 @@ add_sprite(png_imagep output, png_bytep out_buf, struct sprite *sprite,

            /* The read failed: */
            fprintf(stderr, "simpleover: add sprite %s: %s\n", sprite->name,
-                in.message);
+                    in.message);
            return 0; /* error */
         }
      }
@ -379,7 +387,7 @@ add_sprite(png_imagep output, png_bytep out_buf, struct sprite *sprite,
      else
      {
         fprintf(stderr, "simpleover: --add='%s': invalid position %s\n",
-               sprite->name, (*argv)[0]);
+                 sprite->name, (*argv)[0]);
         return 0; /* error */
      }
   }
@ -389,10 +397,10 @@ add_sprite(png_imagep output, png_bytep out_buf, struct sprite *sprite,

 static int
 simpleover_process(png_imagep output, png_bytep out_buf, int argc,
-   const char **argv)
+                   const char **argv)
 {
   int result = 1; /* success */
-#  define csprites 10/*limit*/
+#  define csprites 10 /*limit*/
 #  define str(a) #a
   int nsprites = 0;
   struct sprite sprites[csprites];
@ -412,23 +420,25 @@ simpleover_process(png_imagep output, png_bytep out_buf, int argc,
            sprites[nsprites].width = sprites[nsprites].height = 0;
            sprites[nsprites].name[0] = 0;

-            n = sscanf(argv[0], "--sprite=%u,%u,%" str(sprite_name_chars) "s%c",
-                &sprites[nsprites].width, &sprites[nsprites].height,
-                sprites[nsprites].name, &tombstone);
+            n = sscanf(argv[0],
+                       "--sprite=%u,%u,%" str(sprite_name_chars) "s%c",
+                       &sprites[nsprites].width, &sprites[nsprites].height,
+                       sprites[nsprites].name, &tombstone);

            if ((n == 2 || n == 3) &&
-                sprites[nsprites].width > 0 && sprites[nsprites].height > 0)
+                (sprites[nsprites].width > 0) &&
+                (sprites[nsprites].height > 0))
            {
               size_t buf_size, tmp;

               /* Default a name if not given. */
               if (sprites[nsprites].name[0] == 0)
-                  sprintf(sprites[nsprites].name, "sprite-%d", nsprites+1);
+                  sprintf(sprites[nsprites].name, "sprite-%d", nsprites + 1);

               /* Allocate a buffer for the sprite and calculate the buffer
                * size:
                */
-               buf_size = sizeof (png_uint_16 [4]);
+               buf_size = sizeof(png_uint_16[4]);
               buf_size *= sprites[nsprites].width;
               buf_size *= sprites[nsprites].height;

@ -437,7 +447,7 @@ simpleover_process(png_imagep output, png_bytep out_buf, int argc,
               tmp /= sprites[nsprites].width;
               tmp /= sprites[nsprites].height;

-               if (tmp == sizeof (png_uint_16 [4]))
+               if (tmp == sizeof(png_uint_16[4]))
               {
                  sprites[nsprites].buffer = malloc(buf_size);
                  /* This buffer must be initialized to transparent: */
@ -448,7 +458,7 @@ simpleover_process(png_imagep output, png_bytep out_buf, int argc,
                     sprites[nsprites].file = NULL;
                     ++argv, --argc;

-                     if (create_sprite(sprites+nsprites++, &argc, &argv))
+                     if (create_sprite(sprites + nsprites++, &argc, &argv))
                     {
                        result = 1; /* still ok */
                        continue;
@ -466,7 +476,8 @@ simpleover_process(png_imagep output, png_bytep out_buf, int argc,
            else
            {
               fprintf(stderr, "simpleover: %s: invalid sprite (%u,%u)\n",
-                  argv[0], sprites[nsprites].width, sprites[nsprites].height);
+                       argv[0],
+                       sprites[nsprites].width, sprites[nsprites].height);
               break;
            }
         }
@ -480,7 +491,7 @@ simpleover_process(png_imagep output, png_bytep out_buf, int argc,

      else if (strncmp(argv[0], "--add=", 6) == 0)
      {
-         const char *name = argv[0]+6;
+         const char *name = argv[0] + 6;
         int isprite = nsprites;

         ++argv, --argc;
@ -489,7 +500,8 @@ simpleover_process(png_imagep output, png_bytep out_buf, int argc,
         {
            if (strcmp(sprites[isprite].name, name) == 0)
            {
-               if (!add_sprite(output, out_buf, sprites+isprite, &argc, &argv))
+               if (!add_sprite(output, out_buf, sprites + isprite,
+                               &argc, &argv))
                  goto out; /* error in add_sprite */

               break;
@ -498,7 +510,8 @@ simpleover_process(png_imagep output, png_bytep out_buf, int argc,

         if (isprite < 0) /* sprite not found */
         {
-            fprintf(stderr, "simpleover: --add='%s': sprite not found\n", name);
+            fprintf(stderr, "simpleover: --add='%s': sprite not found\n",
+                    name);
            break;
         }
      }
@ -526,7 +539,8 @@ out:
   return result;
 }

-int main(int argc, const char **argv)
+int
+main(int argc, const char **argv)
 {
   int result = 1; /* default to fail */

@ -536,7 +550,7 @@ int main(int argc, const char **argv)
      const char *output = NULL;
      png_image image;

-      if (argc > 2 && argv[2][0] != '-'/*an operation*/)
+      if (argc > 2 && argv[2][0] != '-' /*an operation*/)
      {
         output = argv[2];
         argi = 3;
@ -558,7 +572,7 @@ int main(int argc, const char **argv)
            png_color background = {0, 0xff, 0}; /* fully saturated green */

            if (png_image_finish_read(&image, &background, buffer,
-               0/*row_stride*/, NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP */))
+                                      0 /*row_stride*/, NULL /*colormap*/))
            {
               /* At this point png_image_finish_read has cleaned up the
                * allocated data in png_image, and only the buffer needs to be
@ -566,22 +580,24 @@ int main(int argc, const char **argv)
                *
                * Perform the remaining operations:
                */
-               if (simpleover_process(&image, buffer, argc-argi, argv+argi))
+               if (simpleover_process(&image, buffer,
+                                      argc - argi, argv + argi))
               {
                  /* Write the output: */
                  if ((output != NULL &&
-                       png_image_write_to_file(&image, output,
-                        0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
-                        NULL/*colormap*/)) ||
+                       png_image_write_to_file(
+                          &image, output, 0 /*convert_to_8bit*/, buffer,
+                          0 /*row_stride*/, NULL /*colormap*/)) ||
                      (output == NULL &&
-                       png_image_write_to_stdio(&image, stdout,
-                        0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
-                        NULL/*colormap*/)))
+                       png_image_write_to_stdio(
+                          &image, stdout, 0 /*convert_to_8bit*/, buffer,
+                          0 /*row_stride*/, NULL /*colormap*/)))
                     result = 0;

                  else
                     fprintf(stderr, "simpleover: write %s: %s\n",
-                        output == NULL ? "stdout" : output, image.message);
+                             output == NULL ? "stdout" : output,
+                             image.message);
               }

               /* else simpleover_process writes an error message */
@ -589,7 +605,7 @@ int main(int argc, const char **argv)

            else
               fprintf(stderr, "simpleover: read %s: %s\n", argv[1],
-                   image.message);
+                       image.message);

            free(buffer);
         }
@ -597,7 +613,7 @@ int main(int argc, const char **argv)
         else
         {
            fprintf(stderr, "simpleover: out of memory: %lu bytes\n",
-               (unsigned long)PNG_IMAGE_SIZE(image));
+                    (unsigned long)PNG_IMAGE_SIZE(image));

            /* This is the only place where a 'free' is required; libpng does
             * the cleanup on error and success, but in this case we couldn't
@ -617,7 +633,8 @@ int main(int argc, const char **argv)
   else
   {
      /* Usage message */
-      fprintf(stderr,
+      fprintf(
+         stderr,
         "simpleover: usage: simpleover background.png [output.png]\n"
         "  Output 'background.png' as a 24-bit RGB PNG file in 'output.png'\n"
         "   or, if not given, stdout.  'background.png' will be composited\n"
@ -628,13 +645,13 @@ int main(int argc, const char **argv)
         "   --sprite=width,height,name {[--at=x,y] {sprite.png}}\n"
         "    Produce a transparent sprite of size (width,height) and with\n"
         "     name 'name'.\n"
-         "    For each sprite.png composite it using a Porter-Duff 'Over'\n"
-         "     operation at offset (x,y) in the sprite (defaulting to (0,0)).\n"
+         "    For each sprite.png composite it is using a Porter-Duff 'Over'\n"
+         "     operation at offset (x,y) in the sprite, defaulting to (0,0).\n"
         "     Input PNGs will be truncated to the area of the sprite.\n"
         "\n"
         "   --add='name' {x,y}\n"
         "    Optionally, before output, composite a sprite, 'name', which\n"
-         "     must have been previously produced using --sprite, at each\n"
+         "     must have been previously produced using --sprite at each\n"
         "     offset (x,y) in the output image.  Each sprite must fit\n"
         "     completely within the output image.\n"
         "\n"
@ -645,4 +662,3 @@ int main(int argc, const char **argv)

   return result;
 }
-#endif /* SIMPLIFIED_READ */
--- a/contrib/libtests/pngimage.c
+++ b/contrib/libtests/pngimage.c
@ -1,4 +1,3 @@
-
 /* pngimage.c
 *
 * Copyright (c) 2021 Cosmin Truta
@ -543,6 +542,7 @@ typedef enum
 struct display
 {
   jmp_buf        error_return;      /* Where to go to on error */
+   error_level    error_code;        /* Set before longjmp */

   const char    *filename;          /* The name of the original file */
   const char    *operation;         /* Operation being performed */
@ -763,7 +763,10 @@ display_log(struct display *dp, error_level level, const char *fmt, ...)

   /* Errors cause this routine to exit to the fail code */
   if (level > APP_FAIL || (level > ERRORS && !(dp->options & CONTINUE)))
+   {
+      dp->error_code = level;
      longjmp(dp->error_return, level);
+    }
 }

 /* error handler callbacks for libpng */
@ -1019,7 +1022,12 @@ compare_read(struct display *dp, int applied_transforms)
   C(height);
   C(bit_depth);
   C(color_type);
-   C(interlace_method);
+#  ifdef PNG_WRITE_INTERLACING_SUPPORTED
+      /* If write interlace has been disabled, the PNG file is still
+       * written correctly, but as a regular (not-interlaced) PNG.
+       */
+      C(interlace_method);
+#  endif
   C(compression_method);
   C(filter_method);

@ -1566,18 +1574,19 @@ static int
 do_test(struct display *dp, const char *file)
   /* Exists solely to isolate the setjmp clobbers */
 {
-   int ret = setjmp(dp->error_return);
+   dp->error_code = VERBOSE; /* The "lowest" level */

-   if (ret == 0)
+   if (setjmp(dp->error_return) == 0)
   {
      test_one_file(dp, file);
      return 0;
   }

-   else if (ret < ERRORS) /* shouldn't longjmp on warnings */
-      display_log(dp, INTERNAL_ERROR, "unexpected return code %d", ret);
+   else if (dp->error_code < ERRORS) /* shouldn't longjmp on warnings */
+      display_log(dp, INTERNAL_ERROR, "unexpected return code %d",
+                  dp->error_code);

-   return ret;
+   return dp->error_code;
 }

 int
@ -1677,7 +1686,11 @@ main(int argc, char **argv)
            int ret = do_test(&d, argv[i]);

            if (ret > QUIET) /* abort on user or internal error */
+            {
+               display_clean(&d);
+               display_destroy(&d);
               return 99;
+            }
         }

         /* Here on any return, including failures, except user/internal issues
--- a/contrib/libtests/pngstest.c
+++ b/contrib/libtests/pngstest.c
@ -1,4 +1,3 @@
-
 /* pngstest.c
 *
 * Copyright (c) 2021 Cosmin Truta
@ -596,7 +595,8 @@ newimage(Image *image)
   memset(image, 0, sizeof *image);
 }

-/* Reset the image to be read again - only needs to rewind the FILE* at present.
+/* Reset the image to be read again - only needs to rewind the FILE object at
+ * present.
 */
 static void
 resetimage(Image *image)
@ -3500,7 +3500,7 @@ main(int argc, char **argv)
   int retval = 0;
   int c;

-#if PNG_LIBPNG_VER >= 10700
+#if PNG_LIBPNG_VER == 10700
      /* This error should not exist in 1.7 or later: */
      opts |= GBG_ERROR;
 #endif
--- a/contrib/libtests/pngunknown.c
+++ b/contrib/libtests/pngunknown.c
@ -1,4 +1,3 @@
-
 /* pngunknown.c - test the read side unknown chunk handling
 *
 * Copyright (c) 2021 Cosmin Truta
@ -114,6 +113,8 @@ typedef png_byte *png_const_bytep;
 #define png_PLTE PNG_U32( 80,  76,  84,  69)
 #define png_bKGD PNG_U32( 98,  75,  71,  68)
 #define png_cHRM PNG_U32( 99,  72,  82,  77)
+#define png_cICP PNG_U32( 99,  73,  67,  80) /* PNGv3 */
+#define png_cLLI PNG_U32( 99,  76,  76,  73) /* PNGv3 */
 #define png_eXIf PNG_U32(101,  88,  73, 102) /* registered July 2017 */
 #define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
 #define png_gAMA PNG_U32(103,  65,  77,  65)
@ -123,6 +124,7 @@ typedef png_byte *png_const_bytep;
 #define png_hIST PNG_U32(104,  73,  83,  84)
 #define png_iCCP PNG_U32(105,  67,  67,  80)
 #define png_iTXt PNG_U32(105,  84,  88, 116)
+#define png_mDCV PNG_U32(109,  68,  67,  86) /* PNGv3 */
 #define png_oFFs PNG_U32(111,  70,  70, 115)
 #define png_pCAL PNG_U32(112,  67,  65,  76)
 #define png_pHYs PNG_U32(112,  72,  89, 115)
@ -209,6 +211,20 @@ static struct
         0,
 #     else
         1,
+#     endif
+      1,  START, 0 },
+   { "cICP", PNG_INFO_cICP, png_cICP,
+#     ifdef PNG_READ_cICP_SUPPORTED
+         0,
+#     else
+         1,
+#     endif
+      1,  START, 0 },
+   { "cLLI", PNG_INFO_cLLI, png_cLLI,
+#     ifdef PNG_READ_cLLI_SUPPORTED
+         0,
+#     else
+         1,
 #     endif
      1,  START, 0 },
   { "eXIf", PNG_INFO_eXIf, png_eXIf,
@ -246,6 +262,13 @@ static struct
         1,
 #     endif
      1, ABSENT, 0 },
+   { "mDCV", PNG_INFO_mDCV, png_mDCV,
+#     ifdef PNG_READ_mDCV_SUPPORTED
+         0,
+#     else
+         1,
+#     endif
+      1,  START, 0 },
   { "oFFs", PNG_INFO_oFFs, png_oFFs,
 #     ifdef PNG_READ_oFFs_SUPPORTED
         0,
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@ -1,4 +1,3 @@
-
 /* pngvalid.c - validate libpng by constructing then reading png files.
 *
 * Copyright (c) 2021 Cosmin Truta
@ -304,20 +303,20 @@ make_four_random_bytes(png_uint_32* seed, png_bytep bytes)
 #if defined PNG_READ_SUPPORTED || defined PNG_WRITE_tRNS_SUPPORTED ||\
    defined PNG_WRITE_FILTER_SUPPORTED
 static void
-randomize(void *pv, size_t size)
+randomize_bytes(void *pv, size_t size)
 {
   static png_uint_32 random_seed[2] = {0x56789abc, 0xd};
   make_random_bytes(random_seed, pv, size);
 }

-#define R8(this) randomize(&(this), sizeof (this))
+#define R8(this) randomize_bytes(&(this), sizeof (this))

 #ifdef PNG_READ_SUPPORTED
 static png_byte
 random_byte(void)
 {
   unsigned char b1[1];
-   randomize(b1, sizeof b1);
+   randomize_bytes(b1, sizeof b1);
   return b1[0];
 }
 #endif /* READ */
@ -326,7 +325,7 @@ static png_uint_16
 random_u16(void)
 {
   unsigned char b2[2];
-   randomize(b2, sizeof b2);
+   randomize_bytes(b2, sizeof b2);
   return png_get_uint_16(b2);
 }

@ -336,7 +335,7 @@ static png_uint_32
 random_u32(void)
 {
   unsigned char b4[4];
-   randomize(b4, sizeof b4);
+   randomize_bytes(b4, sizeof b4);
   return png_get_uint_32(b4);
 }
 #endif /* READ_FILLER || READ_RGB_TO_GRAY */
@ -2574,7 +2573,7 @@ modifier_init(png_modifier *pm)
 * in the rgb_to_gray check, replacing it with an exact copy of the libpng 1.5
 * algorithm.
 */
-#define DIGITIZE PNG_LIBPNG_VER < 10700
+#define DIGITIZE PNG_LIBPNG_VER != 10700

 /* If pm->calculations_use_input_precision is set then operations will happen
 * with the precision of the input, not the precision of the output depth.
@ -3986,7 +3985,7 @@ transform_row(png_const_structp pp, png_byte buffer[TRANSFORM_ROWMAX],
 #  define check_interlace_type(type) ((void)(type))
 #  define set_write_interlace_handling(pp,type) png_set_interlace_handling(pp)
 #  define do_own_interlace 0
-#elif PNG_LIBPNG_VER < 10700
+#elif PNG_LIBPNG_VER != 10700
 #  define set_write_interlace_handling(pp,type) (1)
 static void
 check_interlace_type(int const interlace_type)
@ -4014,7 +4013,7 @@ check_interlace_type(int const interlace_type)
 #  define do_own_interlace 1
 #endif /* WRITE_INTERLACING tests */

-#if PNG_LIBPNG_VER >= 10700 || defined PNG_WRITE_INTERLACING_SUPPORTED
+#if PNG_LIBPNG_VER == 10700 || defined PNG_WRITE_INTERLACING_SUPPORTED
 #   define CAN_WRITE_INTERLACE 1
 #else
 #   define CAN_WRITE_INTERLACE 0
@ -4633,10 +4632,10 @@ static const struct
    {
       /* no warnings makes these errors undetectable prior to 1.7.0 */
       { sBIT0_error_fn, "sBIT(0): failed to detect error",
-         PNG_LIBPNG_VER < 10700 },
+         PNG_LIBPNG_VER != 10700 },

       { sBIT_error_fn, "sBIT(too big): failed to detect error",
-         PNG_LIBPNG_VER < 10700 },
+         PNG_LIBPNG_VER != 10700 },
    };

 static void
@ -6236,7 +6235,7 @@ image_pixel_add_alpha(image_pixel *this, const standard_display *display,
   {
      if (this->colour_type == PNG_COLOR_TYPE_GRAY)
      {
-#        if PNG_LIBPNG_VER < 10700
+#        if PNG_LIBPNG_VER != 10700
            if (!for_background && this->bit_depth < 8)
               this->bit_depth = this->sample_depth = 8;
 #        endif
@ -6246,7 +6245,7 @@ image_pixel_add_alpha(image_pixel *this, const standard_display *display,
            /* After 1.7 the expansion of bit depth only happens if there is a
             * tRNS chunk to expand at this point.
             */
-#           if PNG_LIBPNG_VER >= 10700
+#           if PNG_LIBPNG_VER == 10700
               if (!for_background && this->bit_depth < 8)
                  this->bit_depth = this->sample_depth = 8;
 #           endif
@ -7127,7 +7126,7 @@ image_transform_png_set_tRNS_to_alpha_mod(const image_transform *this,
   image_pixel *that, png_const_structp pp,
   const transform_display *display)
 {
-#if PNG_LIBPNG_VER < 10700
+#if PNG_LIBPNG_VER != 10700
   /* LIBPNG BUG: this always forces palette images to RGB. */
   if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
      image_pixel_convert_PLTE(that);
@ -7137,13 +7136,13 @@ image_transform_png_set_tRNS_to_alpha_mod(const image_transform *this,
    * convert to an alpha channel.
    */
   if (that->have_tRNS)
-#     if PNG_LIBPNG_VER >= 10700
+#     if PNG_LIBPNG_VER == 10700
         if (that->colour_type != PNG_COLOR_TYPE_PALETTE &&
             (that->colour_type & PNG_COLOR_MASK_ALPHA) == 0)
 #     endif
      image_pixel_add_alpha(that, &display->this, 0/*!for background*/);

-#if PNG_LIBPNG_VER < 10700
+#if PNG_LIBPNG_VER != 10700
   /* LIBPNG BUG: otherwise libpng still expands to 8 bits! */
   else
   {
@ -7172,7 +7171,7 @@ image_transform_png_set_tRNS_to_alpha_add(image_transform *this,
    * any action on a palette image.
    */
   return
-#  if PNG_LIBPNG_VER >= 10700
+#  if PNG_LIBPNG_VER == 10700
      colour_type != PNG_COLOR_TYPE_PALETTE &&
 #  endif
   (colour_type & PNG_COLOR_MASK_ALPHA) == 0;
@ -7313,7 +7312,7 @@ image_transform_png_set_expand_gray_1_2_4_to_8_mod(
    const image_transform *this, image_pixel *that, png_const_structp pp,
    const transform_display *display)
 {
-#if PNG_LIBPNG_VER < 10700
+#if PNG_LIBPNG_VER != 10700
   image_transform_png_set_expand_mod(this, that, pp, display);
 #else
   /* Only expand grayscale of bit depth less than 8: */
@ -7329,7 +7328,7 @@ static int
 image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this,
    const image_transform **that, png_byte colour_type, png_byte bit_depth)
 {
-#if PNG_LIBPNG_VER < 10700
+#if PNG_LIBPNG_VER != 10700
   return image_transform_png_set_expand_add(this, that, colour_type,
      bit_depth);
 #else
@ -7359,7 +7358,7 @@ image_transform_png_set_expand_16_set(const image_transform *this,
   png_set_expand_16(pp);

   /* NOTE: prior to 1.7 libpng does SET_EXPAND as well, so tRNS is expanded. */
-#  if PNG_LIBPNG_VER < 10700
+#  if PNG_LIBPNG_VER != 10700
      if (that->this.has_tRNS)
         that->this.is_transparent = 1;
 #  endif
@ -7412,7 +7411,7 @@ image_transform_png_set_scale_16_set(const image_transform *this,
    transform_display *that, png_structp pp, png_infop pi)
 {
   png_set_scale_16(pp);
-#  if PNG_LIBPNG_VER < 10700
+#  if PNG_LIBPNG_VER != 10700
      /* libpng will limit the gamma table size: */
      that->max_gamma_8 = PNG_MAX_GAMMA_8;
 #  endif
@ -7460,7 +7459,7 @@ image_transform_png_set_strip_16_set(const image_transform *this,
    transform_display *that, png_structp pp, png_infop pi)
 {
   png_set_strip_16(pp);
-#  if PNG_LIBPNG_VER < 10700
+#  if PNG_LIBPNG_VER != 10700
      /* libpng will limit the gamma table size: */
      that->max_gamma_8 = PNG_MAX_GAMMA_8;
 #  endif
@ -7647,7 +7646,7 @@ image_transform_png_set_rgb_to_gray_ini(const image_transform *this,
   else
   {
      /* The default (built in) coefficients, as above: */
-#     if PNG_LIBPNG_VER < 10700
+#     if PNG_LIBPNG_VER != 10700
         data.red_coefficient = 6968 / 32768.;
         data.green_coefficient = 23434 / 32768.;
         data.blue_coefficient = 2366 / 32768.;
@ -7730,7 +7729,7 @@ image_transform_png_set_rgb_to_gray_ini(const image_transform *this,
          *  conversion adds another +/-2 in the 16-bit case and
          *  +/-(1<<(15-PNG_MAX_GAMMA_8)) in the 8-bit case.
          */
-#        if PNG_LIBPNG_VER < 10700
+#        if PNG_LIBPNG_VER != 10700
            if (that->this.bit_depth < 16)
               that->max_gamma_8 = PNG_MAX_GAMMA_8;
 #        endif
@ -7907,7 +7906,7 @@ image_transform_png_set_rgb_to_gray_mod(const image_transform *this,
   {
      double gray, err;

-#     if PNG_LIBPNG_VER < 10700
+#     if PNG_LIBPNG_VER != 10700
         if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
            image_pixel_convert_PLTE(that);
 #     endif
@ -8094,7 +8093,7 @@ image_transform_png_set_rgb_to_gray_mod(const image_transform *this,
         double b = that->bluef;
         double be = that->bluee;

-#        if PNG_LIBPNG_VER < 10700
+#        if PNG_LIBPNG_VER != 10700
            /* The true gray case involves no math in earlier versions (not
             * true, there was some if gamma correction was happening too.)
             */
@ -9873,7 +9872,7 @@ gamma_component_validate(const char *name, const validate_info *vi,
             * lost.  This can result in up to a +/-1 error in the presence of
             * an sbit less than the bit depth.
             */
-#           if PNG_LIBPNG_VER < 10700
+#           if PNG_LIBPNG_VER != 10700
 #              define SBIT_ERROR .5
 #           else
 #              define SBIT_ERROR 1.
@ -10733,7 +10732,7 @@ static void perform_gamma_scale16_tests(png_modifier *pm)
 #  ifndef PNG_MAX_GAMMA_8
 #     define PNG_MAX_GAMMA_8 11
 #  endif
-#  if defined PNG_MAX_GAMMA_8 || PNG_LIBPNG_VER < 10700
+#  if defined PNG_MAX_GAMMA_8 || PNG_LIBPNG_VER != 10700
 #     define SBIT_16_TO_8 PNG_MAX_GAMMA_8
 #  else
 #     define SBIT_16_TO_8 16
@ -11736,7 +11735,7 @@ int main(int argc, char **argv)
    * code that 16-bit arithmetic is used for 8-bit samples when it would make a
    * difference.
    */
-   pm.assume_16_bit_calculations = PNG_LIBPNG_VER >= 10700;
+   pm.assume_16_bit_calculations = PNG_LIBPNG_VER == 10700;

   /* Currently 16 bit expansion happens at the end of the pipeline, so the
    * calculations are done in the input bit depth not the output.
@ -11760,13 +11759,13 @@ int main(int argc, char **argv)
   pm.test_lbg_gamma_threshold = 1;
   pm.test_lbg_gamma_transform = PNG_LIBPNG_VER >= 10600;
   pm.test_lbg_gamma_sbit = 1;
-   pm.test_lbg_gamma_composition = PNG_LIBPNG_VER >= 10700;
+   pm.test_lbg_gamma_composition = PNG_LIBPNG_VER == 10700;

   /* And the test encodings */
   pm.encodings = test_encodings;
   pm.nencodings = ARRAY_SIZE(test_encodings);

-#  if PNG_LIBPNG_VER < 10700
+#  if PNG_LIBPNG_VER != 10700
      pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */
 #  else
      pm.sbitlow = 1U;
@ -11796,7 +11795,7 @@ int main(int argc, char **argv)
   pm.maxout16 = .499;  /* Error in *encoded* value */
   pm.maxabs16 = .00005;/* 1/20000 */
   pm.maxcalc16 =1./65535;/* +/-1 in 16 bits for compose errors */
-#  if PNG_LIBPNG_VER < 10700
+#  if PNG_LIBPNG_VER != 10700
      pm.maxcalcG = 1./((1<<PNG_MAX_GAMMA_8)-1);
 #  else
      pm.maxcalcG = 1./((1<<16)-1);
--- a/contrib/libtests/readpng.c
+++ b/contrib/libtests/readpng.c
@ -1,4 +1,3 @@
-
 /* readpng.c
 *
 * Copyright (c) 2013 John Cunningham Bowler
--- a/contrib/libtests/tarith.c
+++ b/contrib/libtests/tarith.c
@ -1,4 +1,3 @@
-
 /* tarith.c
 *
 * Copyright (c) 2021 Cosmin Truta
--- a/contrib/libtests/timepng.c
+++ b/contrib/libtests/timepng.c
@ -1,4 +1,3 @@
-
 /* timepng.c
 *
 * Copyright (c) 2013,2016 John Cunningham Bowler
--- a/contrib/mips-mmi/linux.c
+++ b/contrib/mips-mmi/linux.c
@ -1,4 +1,3 @@
-
 /* contrib/mips-mmi/linux.c
 *
 * Copyright (c) 2024 Cosmin Truta
--- a/contrib/mips-msa/linux.c
+++ b/contrib/mips-msa/linux.c
@ -1,4 +1,3 @@
-
 /* contrib/mips-msa/linux.c
 *
 * Copyright (c) 2020-2023 Cosmin Truta
--- a/Show More
+++ b/Show More