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
189 changed files with 9060 additions and 5937 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
@ -77,5 +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:\msys64\var\cache\pacman
+  - '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
@ -1,28 +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
-  - AUTOMATION=configure
-  - AUTOMATION=makefiles
-
-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_CMAKE_GENERATOR="Xcode"; 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/49
+++ b/49
@ -1,5 +1,13 @@
-libpng 1.6.44 - September 12, 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-1.6.44.tar.xz (LZMA-compressed, recommended)
- * libpng-1.6.44.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):

- * lpng1644.7z (LZMA-compressed, recommended)
- * lpng1644.zip (deflate-compressed)
+ * lpng1650.7z (LZMA-compressed, recommended)
+ * lpng1650.zip (deflate-compressed)

 Other information:

@ -25,29 +33,18 @@ Other information:
 * TRADEMARK.md


-Changes from version 1.6.43 to version 1.6.44
+Changes from version 1.6.49 to version 1.6.50
 ---------------------------------------------

- * 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.
+ * 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)
- * 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.
+ * 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/62
+++ b/62
@ -6218,6 +6218,68 @@ Version 1.6.44 [September 12, 2024]
    (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.
@ -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 1.17 from Makefile.am.
+# Makefile.in generated by automake 1.18.1 from Makefile.am.
 # @configure_input@

-# Copyright (C) 1994-2024 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.
@ -130,8 +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 \
@ -239,6 +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)
@ -332,7 +345,9 @@ 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
 COMPILE = $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) \
 	$(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)
@ -355,12 +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) \
@ -510,7 +527,7 @@ am__common_driver_flags = \
 # 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).
@ -687,7 +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@
@ -827,21 +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@	$(am__append_12)
 pkginclude_HEADERS = png.h pngconf.h
 nodist_pkginclude_HEADERS = pnglibconf.h
 pkgconfig_DATA = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc
@ -875,7 +899,7 @@ SUFFIXES = .chk .out
 SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0' \
 	-DPNGLIB_VERSION='@PNGLIB_VERSION@' \
 	-DSYMBOL_PREFIX='$(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
@ -1087,6 +1111,19 @@ 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)
@ -1202,6 +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
@ -1242,6 +1281,8 @@ 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) $(@D)
@ -1287,6 +1328,20 @@ loongarch/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la-filter_lsx_intrinsics.lo: loo
@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(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

@ -1297,6 +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
@ -1913,6 +1969,7 @@ 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

@ -1966,6 +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)
@ -2009,6 +2070,8 @@ distcheck: dist
 	  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 | $(am__untar) ;;\
 	*.tar.xz*) \
@ -2148,6 +2211,8 @@ distclean-generic:
 	-$(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"
@ -2201,6 +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/$(DEPDIR)/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@rvv_la-riscv_init.Plo
 	-rm -f Makefile
 distclean-am: clean-am distclean-compile distclean-generic \
 	distclean-hdr distclean-libtool distclean-tags
@ -2288,6 +2355,8 @@ maintainer-clean: maintainer-clean-am
 	-rm -f mips/$(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

@ -2320,15 +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 \
--- a/8
+++ b/8
@ -1,5 +1,5 @@
-README for libpng version 1.6.44
-================================
+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 1.17 -*- Autoconf -*-
+# generated automatically by aclocal 1.18.1 -*- Autoconf -*-

-# Copyright (C) 1996-2024 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) 2002-2024 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='1.17'
+[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], [1.17], [],
+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([1.17])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) 2001-2024 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) 2001-2024 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) 1997-2024 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) 1999-2024 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,
@ -352,7 +352,7 @@ _AM_SUBST_NOTMAKE([am__nodep])dnl

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

-# Copyright (C) 1999-2024 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) 1996-2024 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])],
@ -597,7 +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) 2001-2024 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,
@ -618,7 +619,7 @@ if test x"${install_sh+set}" != xset; then
 fi
 AC_SUBST([install_sh])])

-# Copyright (C) 2003-2024 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,
@ -640,7 +641,7 @@ AC_SUBST([am__leading_dot])])
 # Add --enable-maintainer-mode option to configure.         -*- Autoconf -*-
 # From Jim Meyering

-# Copyright (C) 1996-2024 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,
@ -675,7 +676,7 @@ AC_MSG_CHECKING([whether to enable maintainer-specific portions of Makefiles])

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

-# Copyright (C) 2001-2024 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,
@ -718,7 +719,7 @@ AC_SUBST([am__quote])])

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

-# Copyright (C) 1997-2024 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,
@ -752,7 +753,7 @@ fi

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

-# Copyright (C) 2001-2024 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,
@ -781,7 +782,7 @@ AC_DEFUN([_AM_SET_OPTIONS],
 AC_DEFUN([_AM_IF_OPTION],
 [m4_ifset(_AM_MANGLE_OPTION([$1]), [$2], [$3])])

-# Copyright (C) 1999-2024 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,
@ -813,7 +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.
@ -828,7 +832,7 @@ AC_LANG_POP([C])])
 # For backward compatibility.
 AC_DEFUN_ONCE([AM_PROG_CC_C_O], [AC_REQUIRE([AC_PROG_CC])])

-# Copyright (C) 2022-2024 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,
@ -844,7 +848,7 @@ AS_IF([(rm -f && rm -fr && rm -rf) 2>/dev/null], [], [am__rm_f_notfound='""'])
 AC_SUBST(am__rm_f_notfound)
 ])

-# Copyright (C) 2001-2024 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,
@ -863,7 +867,7 @@ AC_DEFUN([AM_RUN_LOG],

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

-# Copyright (C) 1996-2024 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,
@ -1032,10 +1036,12 @@ 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

@ -1088,7 +1094,7 @@ AC_CONFIG_COMMANDS_PRE(
 rm -f conftest.file
 ])

-# Copyright (C) 2009-2024 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,
@ -1157,9 +1163,13 @@ fi
 # empty being verbose).
 AC_DEFUN([AM_SILENT_RULES],
 [AC_REQUIRE([_AM_SILENT_RULES])
-AM_DEFAULT_VERBOSITY=m4_if([$1], [yes], [0], [1])])
+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) 2001-2024 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,
@ -1187,7 +1197,7 @@ fi
 INSTALL_STRIP_PROGRAM="\$(install_sh) -c -s"
 AC_SUBST([INSTALL_STRIP_PROGRAM])])

-# Copyright (C) 2006-2024 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,
@ -1206,7 +1216,7 @@ AC_DEFUN([AM_SUBST_NOTMAKE], [_AM_SUBST_NOTMAKE($@)])

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

-# Copyright (C) 2004-2024 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,
@ -1341,7 +1351,7 @@ AC_SUBST([am__tar])
 AC_SUBST([am__untar])
 ]) # _AM_PROG_TAR

-# Copyright (C) 2022-2024 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,
--- 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
@ -1,4 +1,3 @@
-
 /* filter_neon.S - placeholder file
 *
 * Copyright (c) 2024 Cosmin Truta
--- 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/35
+++ b/35
@ -1,9 +1,9 @@
 #! /bin/sh
 # Wrapper for compilers which do not understand '-c -o'.

-scriptversion=2024-06-19.01; # UTC
+scriptversion=2025-06-18.21; # UTC

-# Copyright (C) 1999-2024 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"`
@ -343,9 +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
@ -4,7 +4,7 @@

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

-timestamp='2024-01-01'
+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
@ -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
@ -634,7 +634,8 @@ EOF
 		sed 's/^		//' << EOF > "$dummy.c"
 		#include <sys/systemcfg.h>

-		main()
+		int
+		main ()
 			{
 			if (!__power_pc())
 				exit(1);
@ -718,7 +719,8 @@ EOF
 		#include <stdlib.h>
 		#include <unistd.h>

-		int main ()
+		int
+		main ()
 		{
 		#if defined(_SC_KERNEL_BITS)
 		    long bits = sysconf(_SC_KERNEL_BITS);
@ -1621,6 +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
@ -2,9 +2,9 @@
 # Configuration validation subroutine script.
 #   Copyright 1992-2024 Free Software Foundation, Inc.

-# shellcheck disable=SC2006,SC2268 # see below for rationale
+# shellcheck disable=SC2006,SC2268,SC2162 # see below for rationale

-timestamp='2024-01-01'
+timestamp='2024-05-27'

 # 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
@ -120,7 +120,6 @@ case $# in
 esac

 # Split fields of configuration type
-# shellcheck disable=SC2162
 saved_IFS=$IFS
 IFS="-" read field1 field2 field3 field4 <<EOF
 $1
@ -142,10 +141,20 @@ case $1 in
 		# parts
 		maybe_os=$field2-$field3
 		case $maybe_os in
-			nto-qnx* | linux-* | uclinux-uclibc* \
-			| uclinux-gnu* | kfreebsd*-gnu* | knetbsd*-gnu* | netbsd*-gnu* \
-			| netbsd*-eabi* | kopensolaris*-gnu* | cloudabi*-eabi* \
-			| storm-chaos* | os2-emx* | rtmk-nova* | managarm-* \
+			  cloudabi*-eabi* \
+			| kfreebsd*-gnu* \
+			| knetbsd*-gnu* \
+			| kopensolaris*-gnu* \
+			| linux-* \
+			| managarm-* \
+			| netbsd*-eabi* \
+			| netbsd*-gnu* \
+			| nto-qnx* \
+			| os2-emx* \
+			| rtmk-nova* \
+			| storm-chaos* \
+			| uclinux-gnu* \
+			| uclinux-uclibc* \
 			| windows-* )
 				basic_machine=$field1
 				basic_os=$maybe_os
@ -161,8 +170,12 @@ case $1 in
 		esac
 		;;
 	*-*)
-		# A lone config we happen to match not fitting any pattern
 		case $field1-$field2 in
+			# Shorthands that happen to contain a single dash
+			convex-c[12] | convex-c3[248])
+				basic_machine=$field2-convex
+				basic_os=
+				;;
 			decstation-3100)
 				basic_machine=mips-dec
 				basic_os=
@ -170,28 +183,88 @@ case $1 in
 			*-*)
 				# Second component is usually, but not always the OS
 				case $field2 in
-					# Prevent following clause from handling this valid os
+					# Do not treat sunos as a manufacturer
 					sun*os*)
 						basic_machine=$field1
 						basic_os=$field2
 						;;
+					# Manufacturers
+					  3100* \
+					| 32* \
+					| 3300* \
+					| 3600* \
+					| 7300* \
+					| acorn \
+					| altos* \
+					| apollo \
+					| apple \
+					| atari \
+					| att* \
+					| axis \
+					| be \
+					| bull \
+					| cbm \
+					| ccur \
+					| cisco \
+					| commodore \
+					| convergent* \
+					| convex* \
+					| cray \
+					| crds \
+					| dec* \
+					| delta* \
+					| dg \
+					| digital \
+					| dolphin \
+					| encore* \
+					| gould \
+					| harris \
+					| highlevel \
+					| hitachi* \
+					| hp \
+					| ibm* \
+					| intergraph \
+					| isi* \
+					| knuth \
+					| masscomp \
+					| microblaze* \
+					| mips* \
+					| motorola* \
+					| ncr* \
+					| news \
+					| next \
+					| ns \
+					| oki \
+					| omron* \
+					| pc533* \
+					| rebel \
+					| rom68k \
+					| rombug \
+					| semi \
+					| sequent* \
+					| siemens \
+					| sgi* \
+					| siemens \
+					| sim \
+					| sni \
+					| sony* \
+					| stratus \
+					| sun \
+					| sun[234]* \
+					| tektronix \
+					| tti* \
+					| ultra \
+					| unicom* \
+					| wec \
+					| winbond \
+					| wrs)
+						basic_machine=$field1-$field2
+						basic_os=
+						;;
 					zephyr*)
 						basic_machine=$field1-unknown
 						basic_os=$field2
 						;;
-					# Manufacturers
-					dec* | mips* | sequent* | encore* | pc533* | sgi* | sony* \
-					| att* | 7300* | 3300* | delta* | motorola* | sun[234]* \
-					| unicom* | ibm* | next | hp | isi* | apollo | altos* \
-					| convergent* | ncr* | news | 32* | 3600* | 3100* \
-					| hitachi* | c[123]* | convex* | sun | crds | omron* | dg \
-					| ultra | tti* | harris | dolphin | highlevel | gould \
-					| cbm | ns | masscomp | apple | axis | knuth | cray \
-					| microblaze* | sim | cisco \
-					| oki | wec | wrs | winbond)
-						basic_machine=$field1-$field2
-						basic_os=
-						;;
 					*)
 						basic_machine=$field1
 						basic_os=$field2
@ -272,26 +345,6 @@ case $1 in
 				basic_machine=arm-unknown
 				basic_os=cegcc
 				;;
-			convex-c1)
-				basic_machine=c1-convex
-				basic_os=bsd
-				;;
-			convex-c2)
-				basic_machine=c2-convex
-				basic_os=bsd
-				;;
-			convex-c32)
-				basic_machine=c32-convex
-				basic_os=bsd
-				;;
-			convex-c34)
-				basic_machine=c34-convex
-				basic_os=bsd
-				;;
-			convex-c38)
-				basic_machine=c38-convex
-				basic_os=bsd
-				;;
 			cray)
 				basic_machine=j90-cray
 				basic_os=unicos
@ -714,15 +767,26 @@ case $basic_machine in
 		vendor=dec
 		basic_os=tops20
 		;;
-	delta | 3300 | motorola-3300 | motorola-delta \
-	      | 3300-motorola | delta-motorola)
+	delta | 3300 | delta-motorola | 3300-motorola | motorola-delta | motorola-3300)
 		cpu=m68k
 		vendor=motorola
 		;;
-	dpx2*)
+	# This used to be dpx2*, but that gets the RS6000-based
+	# DPX/20 and the x86-based DPX/2-100 wrong.  See
+	# https://oldskool.silicium.org/stations/bull_dpx20.htm
+	# https://www.feb-patrimoine.com/english/bull_dpx2.htm
+	# https://www.feb-patrimoine.com/english/unix_and_bull.htm
+	dpx2 | dpx2[23]00 | dpx2[23]xx)
 		cpu=m68k
 		vendor=bull
-		basic_os=sysv3
+		;;
+	dpx2100 | dpx21xx)
+		cpu=i386
+		vendor=bull
+		;;
+	dpx20)
+		cpu=rs6000
+		vendor=bull
 		;;
 	encore | umax | mmax)
 		cpu=ns32k
@ -837,18 +901,6 @@ case $basic_machine in
 	next | m*-next)
 		cpu=m68k
 		vendor=next
-		case $basic_os in
-		    openstep*)
-		        ;;
-		    nextstep*)
-			;;
-		    ns2*)
-		      basic_os=nextstep2
-			;;
-		    *)
-		      basic_os=nextstep3
-			;;
-		esac
 		;;
 	np1)
 		cpu=np1
@ -937,7 +989,6 @@ case $basic_machine in
 		;;

 	*-*)
-		# shellcheck disable=SC2162
 		saved_IFS=$IFS
 		IFS="-" read cpu vendor <<EOF
 $basic_machine
@ -972,15 +1023,19 @@ unset -v basic_machine

 # Decode basic machines in the full and proper CPU-Company form.
 case $cpu-$vendor in
-	# Here we handle the default manufacturer of certain CPU types in canonical form. It is in
-	# some cases the only manufacturer, in others, it is the most popular.
+	# Here we handle the default manufacturer of certain CPU types in canonical form.
+	# It is in some cases the only manufacturer, in others, it is the most popular.
+	c[12]-convex | c[12]-unknown | c3[248]-convex | c3[248]-unknown)
+		vendor=convex
+		basic_os=${basic_os:-bsd}
+		;;
 	craynv-unknown)
 		vendor=cray
 		basic_os=${basic_os:-unicosmp}
 		;;
 	c90-unknown | c90-cray)
 		vendor=cray
-		basic_os=${Basic_os:-unicos}
+		basic_os=${basic_os:-unicos}
 		;;
 	fx80-unknown)
 		vendor=alliant
@ -1026,11 +1081,29 @@ case $cpu-$vendor in
 		vendor=alt
 		basic_os=${basic_os:-linux-gnueabihf}
 		;;
-	dpx20-unknown | dpx20-bull)
-		cpu=rs6000
-		vendor=bull
+
+	# Normalized CPU+vendor pairs that imply an OS, if not otherwise specified
+	m68k-isi)
+		basic_os=${basic_os:-sysv}
+		;;
+	m68k-sony)
+		basic_os=${basic_os:-newsos}
+		;;
+	m68k-tektronix)
+		basic_os=${basic_os:-bsd}
+		;;
+	m88k-harris)
+		basic_os=${basic_os:-sysv3}
+		;;
+	i386-bull | m68k-bull)
+		basic_os=${basic_os:-sysv3}
+		;;
+	rs6000-bull)
 		basic_os=${basic_os:-bosx}
 		;;
+	mips-sni)
+		basic_os=${basic_os:-sysv4}
+		;;

 	# Here we normalize CPU types irrespective of the vendor
 	amd64-*)
@ -1038,7 +1111,7 @@ case $cpu-$vendor in
 		;;
 	blackfin-*)
 		cpu=bfin
-		basic_os=linux
+		basic_os=${basic_os:-linux}
 		;;
 	c54x-*)
 		cpu=tic54x
@ -1061,7 +1134,7 @@ case $cpu-$vendor in
 		;;
 	m68knommu-*)
 		cpu=m68k
-		basic_os=linux
+		basic_os=${basic_os:-linux}
 		;;
 	m9s12z-* | m68hcs12z-* | hcs12z-* | s12z-*)
 		cpu=s12z
@ -1071,7 +1144,7 @@ case $cpu-$vendor in
 		;;
 	parisc-*)
 		cpu=hppa
-		basic_os=linux
+		basic_os=${basic_os:-linux}
 		;;
 	pentium-* | p5-* | k5-* | k6-* | nexgen-* | viac3-*)
 		cpu=i586
@ -1085,9 +1158,6 @@ case $cpu-$vendor in
 	pentium4-*)
 		cpu=i786
 		;;
-	pc98-*)
-		cpu=i386
-		;;
 	ppc-* | ppcbe-*)
 		cpu=powerpc
 		;;
@ -1121,9 +1191,6 @@ case $cpu-$vendor in
 	tx39el-*)
 		cpu=mipstx39el
 		;;
-	x64-*)
-		cpu=x86_64
-		;;
 	xscale-* | xscalee[bl]-*)
 		cpu=`echo "$cpu" | sed 's/^xscale/arm/'`
 		;;
@ -1179,90 +1246,227 @@ case $cpu-$vendor in
 		# Recognize the canonical CPU types that are allowed with any
 		# company name.
 		case $cpu in
-			1750a | 580 \
+			  1750a \
+			| 580 \
+			| [cjt]90 \
 			| a29k \
-			| aarch64 | aarch64_be | aarch64c | arm64ec \
+			| aarch64 \
+			| aarch64_be \
+			| aarch64c \
 			| abacus \
-			| alpha | alphaev[4-8] | alphaev56 | alphaev6[78] \
-			| alpha64 | alpha64ev[4-8] | alpha64ev56 | alpha64ev6[78] \
-			| alphapca5[67] | alpha64pca5[67] \
+			| alpha \
+			| alpha64 \
+			| alpha64ev56 \
+			| alpha64ev6[78] \
+			| alpha64ev[4-8] \
+			| alpha64pca5[67] \
+			| alphaev56 \
+			| alphaev6[78] \
+			| alphaev[4-8] \
+			| alphapca5[67] \
 			| am33_2.0 \
 			| amdgcn \
-			| arc | arceb | arc32 | arc64 \
-			| arm | arm[lb]e | arme[lb] | armv* \
-			| avr | avr32 \
+			| arc \
+			| arc32 \
+			| arc64 \
+			| arceb \
+			| arm \
+			| arm64e \
+			| arm64ec \
+			| arm[lb]e \
+			| arme[lb] \
+			| armv* \
 			| asmjs \
+			| avr \
+			| avr32 \
 			| ba \
-			| be32 | be64 \
-			| bfin | bpf | bs2000 \
-			| c[123]* | c30 | [cjt]90 | c4x \
-			| c8051 | clipper | craynv | csky | cydra \
-			| d10v | d30v | dlx | dsp16xx \
-			| e2k | elxsi | epiphany \
-			| f30[01] | f700 | fido | fr30 | frv | ft32 | fx80 \
-			| javascript \
-			| h8300 | h8500 \
-			| hppa | hppa1.[01] | hppa2.0 | hppa2.0[nw] | hppa64 \
+			| be32 \
+			| be64 \
+			| bfin \
+			| bpf \
+			| bs2000 \
+			| c30 \
+			| c4x \
+			| c8051 \
+			| c[123]* \
+			| clipper \
+			| craynv \
+			| csky \
+			| cydra \
+			| d10v \
+			| d30v \
+			| dlx \
+			| dsp16xx \
+			| e2k \
+			| elxsi \
+			| epiphany \
+			| f30[01] \
+			| f700 \
+			| fido \
+			| fr30 \
+			| frv \
+			| ft32 \
+			| fx80 \
+			| h8300 \
+			| h8500 \
 			| hexagon \
-			| i370 | i*86 | i860 | i960 | ia16 | ia64 \
-			| ip2k | iq2000 \
+			| hppa \
+			| hppa1.[01] \
+			| hppa2.0 \
+			| hppa2.0[nw] \
+			| hppa64 \
+			| i*86 \
+			| i370 \
+			| i860 \
+			| i960 \
+			| ia16 \
+			| ia64 \
+			| ip2k \
+			| iq2000 \
+			| javascript \
 			| k1om \
 			| kvx \
-			| le32 | le64 \
+			| le32 \
+			| le64 \
 			| lm32 \
-			| loongarch32 | loongarch64 \
-			| m32c | m32r | m32rle \
-			| m5200 | m68000 | m680[012346]0 | m68360 | m683?2 | m68k \
-			| m6811 | m68hc11 | m6812 | m68hc12 | m68hcs12x \
-			| m88110 | m88k | maxq | mb | mcore | mep | metag \
-			| microblaze | microblazeel \
+			| loongarch32 \
+			| loongarch64 \
+			| m32c \
+			| m32r \
+			| m32rle \
+			| m5200 \
+			| m68000 \
+			| m680[012346]0 \
+			| m6811 \
+			| m6812 \
+			| m68360 \
+			| m683?2 \
+			| m68hc11 \
+			| m68hc12 \
+			| m68hcs12x \
+			| m68k \
+			| m88110 \
+			| m88k \
+			| maxq \
+			| mb \
+			| mcore \
+			| mep \
+			| metag \
+			| microblaze \
+			| microblazeel \
 			| mips* \
 			| mmix \
-			| mn10200 | mn10300 \
+			| mn10200 \
+			| mn10300 \
 			| moxie \
-			| mt \
 			| msp430 \
+			| mt \
 			| nanomips* \
-			| nds32 | nds32le | nds32be \
+			| nds32 \
+			| nds32be \
+			| nds32le \
 			| nfp \
-			| nios | nios2 | nios2eb | nios2el \
-			| none | np1 | ns16k | ns32k | nvptx \
+			| nios \
+			| nios2 \
+			| nios2eb \
+			| nios2el \
+			| none \
+			| np1 \
+			| ns16k \
+			| ns32k \
+			| nvptx \
 			| open8 \
 			| or1k* \
 			| or32 \
 			| orion \
+			| pdp10 \
+			| pdp11 \
 			| picochip \
-			| pdp10 | pdp11 | pj | pjl | pn | power \
-			| powerpc | powerpc64 | powerpc64le | powerpcle | powerpcspe \
+			| pj \
+			| pjl \
+			| pn \
+			| power \
+			| powerpc \
+			| powerpc64 \
+			| powerpc64le \
+			| powerpcle \
+			| powerpcspe \
 			| pru \
 			| pyramid \
-			| riscv | riscv32 | riscv32be | riscv64 | riscv64be \
-			| rl78 | romp | rs6000 | rx \
-			| s390 | s390x \
+			| riscv \
+			| riscv32 \
+			| riscv32be \
+			| riscv64 \
+			| riscv64be \
+			| rl78 \
+			| romp \
+			| rs6000 \
+			| rx \
+			| s390 \
+			| s390x \
 			| score \
-			| sh | shl \
-			| sh[1234] | sh[24]a | sh[24]ae[lb] | sh[23]e | she[lb] | sh[lb]e \
-			| sh[1234]e[lb] |  sh[12345][lb]e | sh[23]ele | sh64 | sh64le \
-			| sparc | sparc64 | sparc64b | sparc64v | sparc86x | sparclet \
+			| sh \
+			| sh64 \
+			| sh64le \
+			| sh[12345][lb]e \
+			| sh[1234] \
+			| sh[1234]e[lb] \
+			| sh[23]e \
+			| sh[23]ele \
+			| sh[24]a \
+			| sh[24]ae[lb] \
+			| sh[lb]e \
+			| she[lb] \
+			| shl \
+			| sparc \
+			| sparc64 \
+			| sparc64b \
+			| sparc64v \
+			| sparc86x \
+			| sparclet \
 			| sparclite \
-			| sparcv8 | sparcv9 | sparcv9b | sparcv9v | sv1 | sx* \
+			| sparcv8 \
+			| sparcv9 \
+			| sparcv9b \
+			| sparcv9v \
 			| spu \
+			| sv1 \
+			| sx* \
 			| tahoe \
 			| thumbv7* \
-			| tic30 | tic4x | tic54x | tic55x | tic6x | tic80 \
+			| tic30 \
+			| tic4x \
+			| tic54x \
+			| tic55x \
+			| tic6x \
+			| tic80 \
 			| tron \
 			| ubicom32 \
-			| v70 | v850 | v850e | v850e1 | v850es | v850e2 | v850e2v3 \
+			| v70 \
+			| v810 \
+			| v850 \
+			| v850e \
+			| v850e1 \
+			| v850e2 \
+			| v850e2v3 \
+			| v850es \
 			| vax \
 			| vc4 \
 			| visium \
 			| w65 \
-			| wasm32 | wasm64 \
+			| wasm32 \
+			| wasm64 \
 			| we32k \
-			| x86 | x86_64 | xc16x | xgate | xps100 \
-			| xstormy16 | xtensa* \
+			| x86 \
+			| x86_64 \
+			| xc16x \
+			| xgate \
+			| xps100 \
+			| xstormy16 \
+			| xtensa* \
 			| ymp \
-			| z8k | z80)
+			| z80 \
+			| z8k)
 				;;

 			*)
@ -1307,7 +1511,6 @@ case $basic_os in
 		os=`echo "$basic_os" | sed -e 's|nto-qnx|qnx|'`
 		;;
 	*-*)
-		# shellcheck disable=SC2162
 		saved_IFS=$IFS
 		IFS="-" read kernel os <<EOF
 $basic_os
@ -1354,6 +1557,23 @@ case $os in
 	unixware*)
 		os=sysv4.2uw
 		;;
+	# The marketing names for NeXT's operating systems were
+	# NeXTSTEP, NeXTSTEP 2, OpenSTEP 3, OpenSTEP 4.  'openstep' is
+	# mapped to 'openstep3', but 'openstep1' and 'openstep2' are
+	# mapped to 'nextstep' and 'nextstep2', consistent with the
+	# treatment of SunOS/Solaris.
+	ns | ns1 | nextstep | nextstep1 | openstep1)
+		os=nextstep
+		;;
+	ns2 | nextstep2 | openstep2)
+		os=nextstep2
+		;;
+	ns3 | nextstep3 | openstep | openstep3)
+		os=openstep3
+		;;
+	ns4 | nextstep4 | openstep4)
+		os=openstep4
+		;;
 	# es1800 is here to avoid being matched by es* (a different OS)
 	es1800*)
 		os=ose
@ -1424,6 +1644,7 @@ case $os in
 		;;
 	utek*)
 		os=bsd
+		vendor=`echo "$vendor" | sed -e 's|^unknown$|tektronix|'`
 		;;
 	dynix*)
 		os=bsd
@ -1440,21 +1661,25 @@ case $os in
 	386bsd)
 		os=bsd
 		;;
-	ctix* | uts*)
+	ctix*)
+		os=sysv
+		vendor=`echo "$vendor" | sed -e 's|^unknown$|convergent|'`
+		;;
+	uts*)
 		os=sysv
 		;;
 	nova*)
-		os=rtmk-nova
-		;;
-	ns2)
-		os=nextstep2
+		kernel=rtmk
+		os=nova
 		;;
 	# Preserve the version number of sinix5.
 	sinix5.*)
 		os=`echo "$os" | sed -e 's|sinix|sysv|'`
+		vendor=`echo "$vendor" | sed -e 's|^unknown$|sni|'`
 		;;
 	sinix*)
 		os=sysv4
+		vendor=`echo "$vendor" | sed -e 's|^unknown$|sni|'`
 		;;
 	tpf*)
 		os=tpf
@ -1595,6 +1820,14 @@ case $cpu-$vendor in
 		os=
 		obj=elf
 		;;
+	# The -sgi and -siemens entries must be before the mips- entry
+	# or we get the wrong os.
+	*-sgi)
+		os=irix
+		;;
+	*-siemens)
+		os=sysv4
+		;;
 	mips*-cisco)
 		os=
 		obj=elf
@ -1607,7 +1840,8 @@ case $cpu-$vendor in
 		os=
 		obj=coff
 		;;
-	*-tti)	# must be before sparc entry or we get the wrong os.
+	# This must be before the sparc-* entry or we get the wrong os.
+	*-tti)
 		os=sysv3
 		;;
 	sparc-* | *-sun)
@ -1639,7 +1873,7 @@ case $cpu-$vendor in
 		os=hpux
 		;;
 	*-hitachi)
-		os=hiux
+		os=hiuxwe2
 		;;
 	i860-* | *-att | *-ncr | *-altos | *-motorola | *-convergent)
 		os=sysv
@ -1683,12 +1917,6 @@ case $cpu-$vendor in
 	*-encore)
 		os=bsd
 		;;
-	*-sgi)
-		os=irix
-		;;
-	*-siemens)
-		os=sysv4
-		;;
 	*-masscomp)
 		os=rtu
 		;;
@ -1735,40 +1963,193 @@ case $os in
 	ghcjs)
 		;;
 	# Now accept the basic system types.
-	# The portable systems comes first.
 	# Each alternative MUST end in a * to match a version number.
-	gnu* | android* | bsd* | mach* | minix* | genix* | ultrix* | irix* \
-	     | *vms* | esix* | aix* | cnk* | sunos | sunos[34]* \
-	     | hpux* | unos* | osf* | luna* | dgux* | auroraux* | solaris* \
-	     | sym* |  plan9* | psp* | sim* | xray* | os68k* | v88r* \
-	     | hiux* | abug | nacl* | netware* | windows* \
-	     | os9* | macos* | osx* | ios* | tvos* | watchos* \
-	     | mpw* | magic* | mmixware* | mon960* | lnews* \
-	     | amigaos* | amigados* | msdos* | newsos* | unicos* | aof* \
-	     | aos* | aros* | cloudabi* | sortix* | twizzler* \
-	     | nindy* | vxsim* | vxworks* | ebmon* | hms* | mvs* \
-	     | clix* | riscos* | uniplus* | iris* | isc* | rtu* | xenix* \
-	     | mirbsd* | netbsd* | dicos* | openedition* | ose* \
-	     | bitrig* | openbsd* | secbsd* | solidbsd* | libertybsd* | os108* \
-	     | ekkobsd* | freebsd* | riscix* | lynxos* | os400* \
-	     | bosx* | nextstep* | cxux* | oabi* \
-	     | ptx* | ecoff* | winnt* | domain* | vsta* \
-	     | udi* | lites* | ieee* | go32* | aux* | hcos* \
-	     | chorusrdb* | cegcc* | glidix* | serenity* \
-	     | cygwin* | msys* | moss* | proelf* | rtems* \
-	     | midipix* | mingw32* | mingw64* | mint* \
-	     | uxpv* | beos* | mpeix* | udk* | moxiebox* \
-	     | interix* | uwin* | mks* | rhapsody* | darwin* \
-	     | openstep* | oskit* | conix* | pw32* | nonstopux* \
-	     | storm-chaos* | tops10* | tenex* | tops20* | its* \
-	     | os2* | vos* | palmos* | uclinux* | nucleus* | morphos* \
-	     | scout* | superux* | sysv* | rtmk* | tpf* | windiss* \
-	     | powermax* | dnix* | nx6 | nx7 | sei* | dragonfly* \
-	     | skyos* | haiku* | rdos* | toppers* | drops* | es* \
-	     | onefs* | tirtos* | phoenix* | fuchsia* | redox* | bme* \
-	     | midnightbsd* | amdhsa* | unleashed* | emscripten* | wasi* \
-	     | nsk* | powerunix* | genode* | zvmoe* | qnx* | emx* | zephyr* \
-	     | fiwix* | mlibc* | cos* | mbr* | ironclad* )
+	  abug \
+	| aix* \
+	| amdhsa* \
+	| amigados* \
+	| amigaos* \
+	| android* \
+	| aof* \
+	| aos* \
+	| aros* \
+	| atheos* \
+	| auroraux* \
+	| aux* \
+	| beos* \
+	| bitrig* \
+	| bme* \
+	| bosx* \
+	| bsd* \
+	| cegcc* \
+	| chorusos* \
+	| chorusrdb* \
+	| clix* \
+	| cloudabi* \
+	| cnk* \
+	| conix* \
+	| cos* \
+	| cxux* \
+	| cygwin* \
+	| darwin* \
+	| dgux* \
+	| dicos* \
+	| dnix* \
+	| domain* \
+	| dragonfly* \
+	| drops* \
+	| ebmon* \
+	| ecoff* \
+	| ekkobsd* \
+	| emscripten* \
+	| emx* \
+	| es* \
+	| fiwix* \
+	| freebsd* \
+	| fuchsia* \
+	| genix* \
+	| genode* \
+	| glidix* \
+	| gnu* \
+	| go32* \
+	| haiku* \
+	| hcos* \
+	| hiux* \
+	| hms* \
+	| hpux* \
+	| ieee* \
+	| interix* \
+	| ios* \
+	| iris* \
+	| irix* \
+	| ironclad* \
+	| isc* \
+	| its* \
+	| l4re* \
+	| libertybsd* \
+	| lites* \
+	| lnews* \
+	| luna* \
+	| lynxos* \
+	| mach* \
+	| macos* \
+	| magic* \
+	| mbr* \
+	| midipix* \
+	| midnightbsd* \
+	| mingw32* \
+	| mingw64* \
+	| minix* \
+	| mint* \
+	| mirbsd* \
+	| mks* \
+	| mlibc* \
+	| mmixware* \
+	| mon960* \
+	| morphos* \
+	| moss* \
+	| moxiebox* \
+	| mpeix* \
+	| mpw* \
+	| msdos* \
+	| msys* \
+	| mvs* \
+	| nacl* \
+	| netbsd* \
+	| netware* \
+	| newsos* \
+	| nextstep* \
+	| nindy* \
+	| nonstopux* \
+	| nova* \
+	| nsk* \
+	| nucleus* \
+	| nx6 \
+	| nx7 \
+	| oabi* \
+	| ohos* \
+	| onefs* \
+	| openbsd* \
+	| openedition* \
+	| openstep* \
+	| os108* \
+	| os2* \
+	| os400* \
+	| os68k* \
+	| os9* \
+	| ose* \
+	| osf* \
+	| oskit* \
+	| osx* \
+	| palmos* \
+	| phoenix* \
+	| plan9* \
+	| powermax* \
+	| powerunix* \
+	| proelf* \
+	| psos* \
+	| psp* \
+	| ptx* \
+	| pw32* \
+	| qnx* \
+	| rdos* \
+	| redox* \
+	| rhapsody* \
+	| riscix* \
+	| riscos* \
+	| rtems* \
+	| rtmk* \
+	| rtu* \
+	| scout* \
+	| secbsd* \
+	| sei* \
+	| serenity* \
+	| sim* \
+	| skyos* \
+	| solaris* \
+	| solidbsd* \
+	| sortix* \
+	| storm-chaos* \
+	| sunos \
+	| sunos[34]* \
+	| superux* \
+	| syllable* \
+	| sym* \
+	| sysv* \
+	| tenex* \
+	| tirtos* \
+	| toppers* \
+	| tops10* \
+	| tops20* \
+	| tpf* \
+	| tvos* \
+	| twizzler* \
+	| uclinux* \
+	| udi* \
+	| udk* \
+	| ultrix* \
+	| unicos* \
+	| uniplus* \
+	| unleashed* \
+	| unos* \
+	| uwin* \
+	| uxpv* \
+	| v88r* \
+	|*vms* \
+	| vos* \
+	| vsta* \
+	| vxsim* \
+	| vxworks* \
+	| wasi* \
+	| watchos* \
+	| wince* \
+	| windiss* \
+	| windows* \
+	| winnt* \
+	| xenix* \
+	| xray* \
+	| zephyr* \
+	| zvmoe* )
 		;;
 	# This one is extra strict with allowed versions
 	sco3.2v2 | sco3.2v[4-9]* | sco5v6*)
@ -1829,9 +2210,9 @@ esac
 case $kernel-$os-$obj in
 	linux-gnu*- | linux-android*- | linux-dietlibc*- | linux-llvm*- \
 		    | linux-mlibc*- | linux-musl*- | linux-newlib*- \
-		    | linux-relibc*- | linux-uclibc*- )
+		    | linux-relibc*- | linux-uclibc*- | linux-ohos*- )
 		;;
-	uclinux-uclibc*- )
+	uclinux-uclibc*- | uclinux-gnu*- )
 		;;
 	managarm-mlibc*- | managarm-kernel*- )
 		;;
@ -1856,7 +2237,7 @@ case $kernel-$os-$obj in
 		echo "Invalid configuration '$1': '$os' needs 'windows'." 1>&2
 		exit 1
 		;;
-	kfreebsd*-gnu*- | kopensolaris*-gnu*-)
+	kfreebsd*-gnu*- | knetbsd*-gnu*- | netbsd*-gnu*- | kopensolaris*-gnu*-)
 		;;
 	vxworks-simlinux- | vxworks-simwindows- | vxworks-spe-)
 		;;
@ -1864,6 +2245,8 @@ case $kernel-$os-$obj in
 		;;
 	os2-emx-)
 		;;
+	rtmk-nova-)
+		;;
 	*-eabi*- | *-gnueabi*-)
 		;;
 	none--*)
@ -1890,7 +2273,7 @@ case $vendor in
 			*-riscix*)
 				vendor=acorn
 				;;
-			*-sunos*)
+			*-sunos* | *-solaris*)
 				vendor=sun
 				;;
 			*-cnk* | *-aix*)
--- a/1506
+++ b/1506
--- a/configure.ac
+++ b/configure.ac
@ -25,7 +25,7 @@ AC_PREREQ([2.68])

 dnl Version number stuff here:

-AC_INIT([libpng],[1.6.44],[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')
@ -46,10 +46,10 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake

-PNGLIB_VERSION=1.6.44
+PNGLIB_VERSION=1.6.51.git
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=44
+PNGLIB_RELEASE=51

 dnl End of version number stuff

@ -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/contrib/oss-fuzz/Dockerfile
+++ b/contrib/oss-fuzz/Dockerfile
@ -1,5 +1,3 @@
-# Copyright 2024 Cosmin Truta
-# Copyright 2017 Glenn Randers-Pehrson
 # Copyright 2016 Google Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -17,12 +15,11 @@
 ################################################################################

 FROM gcr.io/oss-fuzz-base/base-builder
-
+MAINTAINER glennrp@gmail.com
 RUN apt-get update && \
-    apt-get install -y make autoconf automake libtool zlib1g-dev
+    apt-get install -y make autoconf automake libtool

-RUN git clone --depth=1 https://github.com/pnggroup/libpng.git && \
-    git clone --depth=1 https://github.com/madler/zlib.git && \
-    cp libpng/contrib/oss-fuzz/build.sh $SRC
-
-WORKDIR /home/libpng
+RUN git clone --depth 1 https://github.com/madler/zlib.git
+RUN git clone --depth 1 https://github.com/glennrp/libpng.git
+RUN cp libpng/contrib/oss-fuzz/build.sh $SRC
+WORKDIR libpng
--- a/contrib/oss-fuzz/README.txt
+++ b/contrib/oss-fuzz/README.txt
@ -1,7 +1,3 @@
-libpng additions to oss-fuzz
-============================
-
-Copyright (c) 2024 Cosmin Truta
 Copyright (c) 2017 Glenn Randers-Pehrson

 This code is released under the libpng license.
--- a/contrib/oss-fuzz/build.sh
+++ b/contrib/oss-fuzz/build.sh
@ -1,8 +1,6 @@
-#!/usr/bin/env bash
-set -eu
+#!/bin/bash -eu

-# Copyright 2024 Cosmin Truta
-# Copyright 2017 Glenn Randers-Pehrson
+# Copyright 2017-2018 Glenn Randers-Pehrson
 # Copyright 2016 Google Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -17,31 +15,36 @@ set -eu
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+# Revisions by Glenn Randers-Pehrson, 2017:
+# 1. Build only the library, not the tools (changed "make -j$(nproc) all" to
+#     "make -j$(nproc) libpng16.la").
+# 2. Disabled WARNING and WRITE options in pnglibconf.dfa.
+# 3. Build zlib alongside libpng
 ################################################################################

 # Disable logging via library build configuration control.
-sed -e "s/option STDIO/option STDIO disabled/" \
-    -e "s/option WARNING /option WARNING disabled/" \
-    -e "s/option WRITE enables WRITE_INT_FUNCTIONS/option WRITE disabled/" \
-    scripts/pnglibconf.dfa >scripts/pnglibconf.dfa.tmp
-mv -f scripts/pnglibconf.dfa.tmp scripts/pnglibconf.dfa
+cat scripts/pnglibconf.dfa | \
+  sed -e "s/option STDIO/option STDIO disabled/" \
+      -e "s/option WARNING /option WARNING disabled/" \
+      -e "s/option WRITE enables WRITE_INT_FUNCTIONS/option WRITE disabled/" \
+> scripts/pnglibconf.dfa.temp
+mv scripts/pnglibconf.dfa.temp scripts/pnglibconf.dfa

-# Build the libpng library ("libpng16.la"), excluding the auxiliary tools.
+# build the libpng library.
 autoreconf -f -i
 ./configure --with-libpng-prefix=OSS_FUZZ_
 make -j$(nproc) clean
 make -j$(nproc) libpng16.la

-# Build libpng_read_fuzzer.
+# build libpng_read_fuzzer.
 $CXX $CXXFLAGS -std=c++11 -I. \
     $SRC/libpng/contrib/oss-fuzz/libpng_read_fuzzer.cc \
     -o $OUT/libpng_read_fuzzer \
     -lFuzzingEngine .libs/libpng16.a -lz

-# Add seed corpus.
+# add seed corpus.
 find $SRC/libpng -name "*.png" | grep -v crashers | \
     xargs zip $OUT/libpng_read_fuzzer_seed_corpus.zip

 cp $SRC/libpng/contrib/oss-fuzz/*.dict \
-   $SRC/libpng/contrib/oss-fuzz/*.options \
-   $OUT/
+     $SRC/libpng/contrib/oss-fuzz/*.options $OUT/
--- a/contrib/oss-fuzz/libpng_read_fuzzer.cc
+++ b/contrib/oss-fuzz/libpng_read_fuzzer.cc
@ -1,4 +1,3 @@
-
 // libpng_read_fuzzer.cc
 // Copyright 2017-2018 Glenn Randers-Pehrson
 // Copyright 2015 The Chromium Authors. All rights reserved.
--- a/contrib/pngexif/.editorconfig
+++ b/contrib/pngexif/.editorconfig
@ -4,6 +4,7 @@ root = true

 [*]
 charset = utf-8
+indent_size = 4
 indent_style = space
 insert_final_newline = true
 max_doc_length = 79
--- a/contrib/pngminim/README
+++ b/contrib/pngminim/README
@ -1,4 +1,3 @@
-
 This demonstrates the use of PNG_USER_CONFIG, pngusr.h and pngusr.dfa
 to build minimal decoder, encoder, and progressive reader applications.

--- a/contrib/pngminus/.editorconfig
+++ b/contrib/pngminus/.editorconfig
@ -0,0 +1,29 @@
+# https://editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = unset
+indent_size = unset
+indent_style = space
+insert_final_newline = true
+max_doc_length = 79
+max_line_length = 79
+trim_trailing_whitespace = true
+
+[*.[ch]]
+indent_size = 2
+indent_style = space
+
+[CMakeLists.txt]
+indent_size = 4
+indent_style = space
+max_doc_length = 79
+max_line_length = 99
+
+[{Makefile,makevms.com}]
+indent_size = unset
+indent_style = unset
+max_doc_length = 79
+max_line_length = 99
--- a/contrib/pngminus/CHANGES.txt
+++ b/contrib/pngminus/CHANGES.txt
@ -1,4 +1,3 @@
-
 pnm2png / png2pnm --- conversion from PBM/PGM/PPM-file to PNG-file
 copyright (C) 1999-2019 by Willem van Schaik <willem at schaik dot com>

@ -12,3 +11,4 @@ version 1.0 - 1999.10.15 - First version.
        1.6 - 2018.08.05 - Improve portability and fix style (Cosmin Truta)
        1.7 - 2019.01.22 - Change license to MIT (Willem van Schaik)
        1.8 - 2024.01.09 - Fix, improve, modernize (Cosmin Truta)
+        1.9 - 2025.01.10 - Delete conditionally-compiled code (Cosmin Truta)
--- a/contrib/pngminus/CMakeLists.txt
+++ b/contrib/pngminus/CMakeLists.txt
@ -1,9 +1,9 @@
-# Copyright (c) 2018-2024 Cosmin Truta
+# Copyright (c) 2018-2025 Cosmin Truta
 #
 # This software is released under the MIT license. For conditions of
 # distribution and use, see the LICENSE file part of this package.

-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.14)

 project(PNGMINUS C)

--- a/contrib/pngminus/LICENSE.txt
+++ b/contrib/pngminus/LICENSE.txt
@ -1,4 +1,3 @@
-
 pnm2png / png2pnm --- conversion from PBM/PGM/PPM-file to PNG-file

 copyright (C) 1999-2019 by Willem van Schaik <willem at schaik dot com>
--- a/contrib/pngminus/png2pnm.c
+++ b/contrib/pngminus/png2pnm.c
@ -66,7 +66,7 @@ int main (int argc, char *argv[])
          if ((fp_al = fopen (argv[argi], "wb")) == NULL)
          {
            fname_al = argv[argi];
-            fprintf (stderr, "PNM2PNG\n");
+            fprintf (stderr, "PNG2PNM\n");
            fprintf (stderr, "Error:  cannot create alpha-channel file %s\n",
                     argv[argi]);
            exit (1);
@ -235,22 +235,6 @@ BOOL do_png2pnm (png_struct *png_ptr, png_info *info_ptr,
  /* set up (if applicable) the expansion of grayscale images to bit-depth 8 */
  png_set_expand_gray_1_2_4_to_8 (png_ptr);

-#ifdef NJET
-  /* downgrade 16-bit images to 8-bit */
-  if (bit_depth == 16)
-    png_set_strip_16 (png_ptr);
-  /* transform grayscale images into full-color */
-  if (color_type == PNG_COLOR_TYPE_GRAY ||
-      color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-    png_set_gray_to_rgb (png_ptr);
-  /* if the PNG image has a gAMA chunk then gamma-correct the output image */
-  {
-    double file_gamma;
-    if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
-      png_set_gamma (png_ptr, (double) 2.2, file_gamma);
-  }
-#endif
-
  /* read the image file, with all of the above image transforms applied */
  png_read_png (png_ptr, info_ptr, 0, NULL);

--- a/contrib/pngsuite/README
+++ b/contrib/pngsuite/README
@ -1,4 +1,3 @@
-
 pngsuite
 --------
 Copyright (c) Willem van Schaik, 1999, 2011, 2012
--- a/contrib/pngsuite/interlaced/README
+++ b/contrib/pngsuite/interlaced/README
@ -1,2 +1 @@
-
 These images fail the "pngimage-quick" and "pngimage-full" tests.
--- a/contrib/riscv-rvv/README
+++ b/contrib/riscv-rvv/README
@ -0,0 +1,85 @@
+OPERATING SYSTEM SPECIFIC RISC-V RVV DETECTION
+----------------------------------------------
+
+Detection of the ability to execute RISC-V Vector on a RISC-V processor
+requires operating system support.  (The information is not available in user
+mode.)
+
+HOW TO USE THIS
+---------------
+
+This directory contains C code fragments that can be included in
+riscv/riscv_init.c by setting the macro PNG_RISCV_RVV_FILE to the file name
+in "" or <> at build time.  This setting is not recorded in pnglibconf.h and
+can be changed simply by rebuilding riscv/riscv_init.o with the required macro
+definition.
+
+For any of this code to be used the RISC-V Vector code must be enabled and run
+time checks must be supported.  I.e.:
+
+#if PNG_RISCV_RVV_OPT > 0
+#ifdef PNG_RISCV_RVV_CHECK_SUPPORTED
+
+This is done in a 'configure' build by passing configure the argument:
+
+   --enable-riscv-rvv=check
+
+Apart from the basic Linux implementation in contrib/riscv-rvv/linux.c this
+code is unsupported.  That means that it is not even compiled on a regular
+basis and may be broken in any given minor release.
+
+FILE FORMAT
+-----------
+
+Each file documents its testing status as of the last time it was tested (which
+may have been a long time ago):
+
+STATUS: one of:
+   SUPPORTED: This indicates that the file is included in the regularly
+         performed test builds and bugs are fixed when discovered.
+   COMPILED: This indicates that the code did compile at least once.  See the
+         more detailed description for the extent to which the result was
+         successful.
+   TESTED: This means the code was fully compiled into the libpng test programs
+         and these were run at least once.
+
+BUG REPORTS: an email address to which to send reports of problems
+
+The file is a fragment of C code. It should not define any 'extern' symbols;
+everything should be static.  It must define the function:
+
+static int png_have_rvv(png_structp png_ptr);
+
+That function must return 1 if RISC-V Vector instructions are supported, 0 if
+not.  It must not execute png_error unless it detects a bug.  A png_error will
+prevent the reading of the PNG and in the future, writing too.
+
+BUG REPORTS
+-----------
+
+If you mail a bug report for any file that is not SUPPORTED there may only be
+limited response.  Consider fixing it and sending a patch to fix the problem -
+this is more likely to result in action.
+
+CONTRIBUTIONS
+-------------
+
+You may send contributions of new implementations to
+png-mng-implement@sourceforge.net.  Please write code in strict C90 C where
+possible.  Obviously OS dependencies are to be expected.  If you submit code you
+must have the authors permission and it must have a license that is acceptable
+to the current maintainer; in particular that license must permit modification
+and redistribution.
+
+Please try to make the contribution a single file and give the file a clear and
+unambiguous name that identifies the target OS.  If multiple files really are
+required put them all in a sub-directory.
+
+You must also be prepared to handle bug reports from users of the code, either
+by joining the png-mng-implement mailing list or by providing an email for the
+"BUG REPORTS" entry or both.  Please make sure that the header of the file
+contains the STATUS and BUG REPORTS fields as above.
+
+Please list the OS requirements as precisely as possible.  Ideally you should
+also list the environment in which the code has been tested and certainly list
+any environments where you suspect it might not work.
--- a/contrib/riscv-rvv/linux.c
+++ b/contrib/riscv-rvv/linux.c
@ -0,0 +1,36 @@
+/* contrib/riscv-rvv/linux.c
+ *
+ * Copyright (c) 2023 Google LLC
+ * Written by Dragoș Tiselice <dtiselice@google.com>, May 2023.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * SEE contrib/riscv-rvv/README before reporting bugs
+ *
+ * STATUS: SUPPORTED
+ * BUG REPORTS: png-mng-implement@sourceforge.net
+ *
+ * png_have_rvv implemented for Linux by looking for COMPAT_HWCAP_ISA_V
+ * via hardware capabilites API.
+ *
+ * This code is strict ANSI-C and is probably moderately portable; it does
+ * however use <stdio.h> and it assumes that /proc/cpuinfo is never localized.
+ */
+
+#if defined(__linux__)
+#include <asm/hwcap.h>
+#include <sys/auxv.h>
+#endif
+
+static int
+png_have_rvv() {
+#if defined(__linux__)
+   return getauxval (AT_HWCAP) & COMPAT_HWCAP_ISA_V ? 1 : 0;
+#else
+#pragma message(                                                               \
+   "warning: RISC-V Vector not supported for this platform")
+   return 0;
+#endif
+}
--- a/contrib/testpngs/png-3/cicp-display-p3_reencoded.png
+++ b/contrib/testpngs/png-3/cicp-display-p3_reencoded.png
--- a/contrib/tools/pngfix.c
+++ b/contrib/tools/pngfix.c
@ -32,7 +32,7 @@
 #endif

 #if PNG_LIBPNG_VER < 10603 /* 1.6.3 */
-#  error "pngfix will not work with libpng prior to 1.6.3"
+#  error pngfix requires libpng version 1.6.3 or newer
 #endif

 #ifdef PNG_SETJMP_SUPPORTED
@ -68,7 +68,7 @@
 #endif

 #ifndef PNG_MAXIMUM_INFLATE_WINDOW
-#  error "pngfix not supported in this libpng version"
+#  error pngfix requires libpng with PNG_MAXIMUM_INFLATE_WINDOW supported
 #endif

 #if ZLIB_VERNUM >= 0x1240
--- a/contrib/visupng/.editorconfig
+++ b/contrib/visupng/.editorconfig
@ -5,7 +5,8 @@ root = true
 [*]
 charset = utf-8
 end_of_line = unset
-indent_style = unset
+indent_size = 4
+indent_style = space
 insert_final_newline = true
 max_doc_length = 80
 max_line_length = 100
--- a/8
+++ b/8
@ -1,9 +1,9 @@
 #! /bin/sh
 # depcomp - compile a program generating dependencies as side-effects

-scriptversion=2024-06-19.01; # UTC
+scriptversion=2025-06-18.21; # UTC

-# Copyright (C) 1999-2024 Free Software Foundation, Inc.
+# Copyright (C) 1999-2025 Free Software Foundation, Inc.

 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@ -784,9 +784,9 @@ exit 0
 # 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/example.c
+++ b/example.c
@ -1,9 +1,8 @@
-
 #if 0 /* in case someone actually tries to compile this */

 /* example.c - an example of using libpng
 *
- * Maintained 2018-2024 Cosmin Truta
+ * Maintained 2018-2025 Cosmin Truta
 * Maintained 1998-2016 Glenn Randers-Pehrson
 * Maintained 1996-1997 Andreas Dilger
 * Written 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@ -180,11 +179,11 @@ int main(int argc, const char **argv)
 *    components.
 *
 * You do not have to read directly from a file.  You can read from memory or,
- * on systems that support it, from a <stdio.h> FILE*.  This is controlled by
- * the particular png_image_read_from_ function you call at the start.
- * Likewise, on write, you can write to a FILE* if your system supports it.
- * Check the macro PNG_STDIO_SUPPORTED to see if stdio support has been
- * included in your libpng build.
+ * on systems that support <stdio.h>, from a FILE object.  This is controlled
+ * by the particular png_image_begin_read_from_ function you call at the start.
+ * Likewise, on write, you can write to a FILE object if your system supports
+ * <stdio.h>.  The macro PNG_STDIO_SUPPORTED indicates if stdio is available
+ * and accessible from your libpng build.
 *
 * If you read 16-bit (PNG_FORMAT_FLAG_LINEAR) data, you may need to write it
 * in the 8-bit format for display.  You do this by setting the convert_to_8bit
--- a/6
+++ b/6
@ -1,7 +1,7 @@
 #!/bin/sh
 # install - install a program, script, or datafile

-scriptversion=2024-06-19.01; # UTC
+scriptversion=2025-06-18.21; # UTC

 # This originates from X11R5 (mit/util/scripts/install.sh), which was
 # later released in X11R6 (xc/config/util/install.sh) with the
@ -533,9 +533,9 @@ do
 done

 # Local variables:
-# 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/intel/filter_sse2_intrinsics.c
+++ b/intel/filter_sse2_intrinsics.c
@ -1,4 +1,3 @@
-
 /* filter_sse2_intrinsics.c - SSE2 optimized filter functions
 *
 * Copyright (c) 2018 Cosmin Truta
--- a/intel/intel_init.c
+++ b/intel/intel_init.c
@ -1,4 +1,3 @@
-
 /* intel_init.c - SSE2 optimized filter functions
 *
 * Copyright (c) 2018 Cosmin Truta
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng

- Copyright (c) 2018-2024 Cosmin Truta
+ Copyright (c) 2018-2025 Cosmin Truta
 Copyright (c) 1998-2018 Glenn Randers-Pehrson

 This document is released under the libpng license.
@ -9,9 +9,9 @@ libpng-manual.txt - A description on how to use and modify libpng

 Based on:

- libpng version 1.6.36, December 2018, through 1.6.44 - September 2024
+ libpng version 1.6.36, December 2018, through 1.6.50 - July 2025
 Updated and distributed by Cosmin Truta
- Copyright (c) 2018-2024 Cosmin Truta
+ Copyright (c) 2018-2025 Cosmin Truta

 libpng versions 0.97, January 1998, through 1.6.35 - July 2018
 Updated and distributed by Glenn Randers-Pehrson
@ -65,18 +65,22 @@ Libpng was written as a companion to the PNG specification, as a way
 of reducing the amount of time and effort it takes to support the PNG
 file format in application programs.

-The PNG specification (second edition), November 2003, is available as
+The PNG specification (Third Edition), June 2025, is available as
+a W3C Recommendation at
+<https://www.w3.org/TR/2025/REC-png-3-20250624/>.
+
+The PNG specification (Second Edition), November 2003, is available as
 a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at
 <https://www.w3.org/TR/2003/REC-PNG-20031110/>.
 The W3C and ISO documents have identical technical content.

 The PNG-1.2 specification is available at
-<https://png-mng.sourceforge.io/pub/png/spec/1.2/>.
-It is technically equivalent
-to the PNG specification (second edition) but has some additional material.
+<https://www.libpng.org/pub/png/spec/1.2/>.
+It is technically equivalent to the PNG specification (Second Edition)
+but has some additional material.

 The PNG-1.0 specification is available as RFC 2083 at
-<https://png-mng.sourceforge.io/pub/png/spec/1.0/> and as a
+<https://www.libpng.org/pub/png/spec/1.0/> and as a
 W3C Recommendation at <https://www.w3.org/TR/REC-png-961001>.

 Some additional chunks are described in the special-purpose public chunks
@ -4089,7 +4093,7 @@ READ APIs
     is filled in from the PNG header in the file.

   int png_image_begin_read_from_stdio (png_imagep image,
-     FILE* file)
+     FILE *file)

      The PNG header is read from the stdio FILE object.

@ -4164,7 +4168,7 @@ be written:
      int convert_to_8_bit, const void *buffer,
      png_int_32 row_stride, const void *colormap)

-      Write the image to the given (FILE*).
+      Write the image to the given FILE object.

 With all write APIs if image is in one of the linear formats with
 (png_uint_16) data then setting convert_to_8_bit will cause the output to be
@ -5173,7 +5177,7 @@ a pre-existing bug where the per-chunk 'keep' setting is ignored, and makes
 it possible to skip IDAT chunks in the sequential reader.

 The machine-generated configure files are no longer included in branches
-libpng16 and later of the GIT repository.  They continue to be included
+libpng17 and later of the GIT repository.  They continue to be included
 in the tarball releases, however.

 Libpng-1.6.0 through 1.6.2 used the CMF bytes at the beginning of the IDAT
--- a/libpng.3
+++ b/libpng.3
@ -1,6 +1,6 @@
-.TH LIBPNG 3 "September 12, 2024"
+.TH LIBPNG 3 "July 1, 2025"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.44
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.50

 .SH SYNOPSIS
 \fB#include <png.h>\fP
@ -223,7 +223,7 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.44

 \fBint png_image_begin_read_from_file (png_imagep \fP\fIimage\fP\fB, const char \fI*file_name\fP\fB);\fP

-\fBint png_image_begin_read_from_stdio (png_imagep \fP\fIimage\fP\fB, FILE* \fIfile\fP\fB);\fP
+\fBint png_image_begin_read_from_stdio (png_imagep \fP\fIimage\fP\fB, FILE *\fIfile\fP\fB);\fP

 \fBint, png_image_begin_read_from_memory (png_imagep \fP\fIimage\fP\fB, png_const_voidp \fP\fImemory\fP\fB, size_t \fIsize\fP\fB);\fP

@ -519,7 +519,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng

- Copyright (c) 2018-2024 Cosmin Truta
+ Copyright (c) 2018-2025 Cosmin Truta
 Copyright (c) 1998-2018 Glenn Randers-Pehrson

 This document is released under the libpng license.
@ -528,9 +528,9 @@ libpng-manual.txt - A description on how to use and modify libpng

 Based on:

- libpng version 1.6.36, December 2018, through 1.6.44 - September 2024
+ libpng version 1.6.36, December 2018, through 1.6.50 - July 2025
 Updated and distributed by Cosmin Truta
- Copyright (c) 2018-2024 Cosmin Truta
+ Copyright (c) 2018-2025 Cosmin Truta

 libpng versions 0.97, January 1998, through 1.6.35 - July 2018
 Updated and distributed by Glenn Randers-Pehrson
@ -584,18 +584,22 @@ Libpng was written as a companion to the PNG specification, as a way
 of reducing the amount of time and effort it takes to support the PNG
 file format in application programs.

-The PNG specification (second edition), November 2003, is available as
+The PNG specification (Third Edition), June 2025, is available as
+a W3C Recommendation at
+<https://www.w3.org/TR/2025/REC-png-3-20250624/>.
+
+The PNG specification (Second Edition), November 2003, is available as
 a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at
 <https://www.w3.org/TR/2003/REC-PNG-20031110/>.
 The W3C and ISO documents have identical technical content.

 The PNG-1.2 specification is available at
-<https://png-mng.sourceforge.io/pub/png/spec/1.2/>.
-It is technically equivalent
-to the PNG specification (second edition) but has some additional material.
+<https://www.libpng.org/pub/png/spec/1.2/>.
+It is technically equivalent to the PNG specification (Second Edition)
+but has some additional material.

 The PNG-1.0 specification is available as RFC 2083 at
-<https://png-mng.sourceforge.io/pub/png/spec/1.0/> and as a
+<https://www.libpng.org/pub/png/spec/1.0/> and as a
 W3C Recommendation at <https://www.w3.org/TR/REC-png-961001>.

 Some additional chunks are described in the special-purpose public chunks
@ -4608,7 +4612,7 @@ READ APIs
     is filled in from the PNG header in the file.

   int png_image_begin_read_from_stdio (png_imagep image,
-     FILE* file)
+     FILE *file)

      The PNG header is read from the stdio FILE object.

@ -4683,7 +4687,7 @@ be written:
      int convert_to_8_bit, const void *buffer,
      png_int_32 row_stride, const void *colormap)

-      Write the image to the given (FILE*).
+      Write the image to the given FILE object.

 With all write APIs if image is in one of the linear formats with
 (png_uint_16) data then setting convert_to_8_bit will cause the output to be
@ -5692,7 +5696,7 @@ a pre-existing bug where the per-chunk 'keep' setting is ignored, and makes
 it possible to skip IDAT chunks in the sequential reader.

 The machine-generated configure files are no longer included in branches
-libpng16 and later of the GIT repository.  They continue to be included
+libpng17 and later of the GIT repository.  They continue to be included
 in the tarball releases, however.

 Libpng-1.6.0 through 1.6.2 used the CMF bytes at the beginning of the IDAT
--- a/libpngpf.3
+++ b/libpngpf.3
@ -1,24 +1,17 @@
-.TH LIBPNGPF 3 "September 12, 2024"
+.TH LIBPNGPF 3 "July 1, 2025"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.44
-(private functions)
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.50

 .SH SYNOPSIS
-\fB#include \fI"pngpriv.h"
-
-\fBAs of libpng version \fP\fI1.5.1\fP\fB, this section is no longer
-\fP\fImaintained\fP\fB, now that the private function prototypes are hidden in
-\fP\fIpngpriv.h\fP\fB and not accessible to applications. Look in
-\fP\fIpngpriv.h\fP\fB for the prototypes and a short description of each
-function.
+\fB#include "pngpriv.h"\fP

 .SH DESCRIPTION
-The functions previously listed here are used privately by libpng and are not
-available for use by applications.  They are not "exported" to applications
-using shared libraries.
+As of libpng version 1.5.1, this manual is no longer maintained.  The private
+function prototypes, declared in private header files, should not be accessed
+by applications.

 .SH "SEE ALSO"
-.BR "png"(5), " libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
+.BR "libpng"(3)

 .SH AUTHORS
 Cosmin Truta, Glenn Randers-Pehrson
--- a/ltmain.sh
+++ b/ltmain.sh
--- a/mips/filter_msa_intrinsics.c
+++ b/mips/filter_msa_intrinsics.c
@ -1,4 +1,3 @@
-
 /* filter_msa_intrinsics.c - MSA optimised filter functions
 *
 * Copyright (c) 2018-2024 Cosmin Truta
@ -47,7 +46,7 @@
       uint8_t *psrc_lw_m = (uint8_t *) (psrc);  \
       uint32_t val_m;                           \
                                                 \
-       asm volatile (                            \
+       __asm__ volatile (                        \
           "lw  %[val_m],  %[psrc_lw_m]  \n\t"   \
                                                 \
           : [val_m] "=r" (val_m)                \
@ -62,7 +61,7 @@
       uint8_t *pdst_sh_m = (uint8_t *) (pdst);  \
       uint16_t val_m = (val);                   \
                                                 \
-       asm volatile (                            \
+       __asm__ volatile (                        \
           "sh  %[val_m],  %[pdst_sh_m]  \n\t"   \
                                                 \
           : [pdst_sh_m] "=m" (*pdst_sh_m)       \
@ -75,7 +74,7 @@
       uint8_t *pdst_sw_m = (uint8_t *) (pdst);  \
       uint32_t val_m = (val);                   \
                                                 \
-       asm volatile (                            \
+       __asm__ volatile (                        \
           "sw  %[val_m],  %[pdst_sw_m]  \n\t"   \
                                                 \
           : [pdst_sw_m] "=m" (*pdst_sw_m)       \
@ -83,20 +82,20 @@
       );                                        \
   }

-       #if (__mips == 64)
+   #if __mips == 64
        #define SD(val, pdst)                         \
        {                                             \
            uint8_t *pdst_sd_m = (uint8_t *) (pdst);  \
            uint64_t val_m = (val);                   \
                                                      \
-            asm volatile (                            \
+            __asm__ volatile (                        \
                "sd  %[val_m],  %[pdst_sd_m]  \n\t"   \
                                                      \
                : [pdst_sd_m] "=m" (*pdst_sd_m)       \
                : [val_m] "r" (val_m)                 \
            );                                        \
        }
-    #else
+   #else
        #define SD(val, pdst)                                          \
        {                                                              \
            uint8_t *pdst_sd_m = (uint8_t *) (pdst);                   \
@ -108,17 +107,17 @@
            SW(val0_m, pdst_sd_m);                                     \
            SW(val1_m, pdst_sd_m + 4);                                 \
        }
-    #endif
+   #endif /* __mips == 64 */
 #else
   #define MSA_SRLI_B(a, b)   (a >> b)

-#if (__mips_isa_rev >= 6)
+#if __mips_isa_rev >= 6
   #define LW(psrc)                              \
   ( {                                           \
       uint8_t *psrc_lw_m = (uint8_t *) (psrc);  \
       uint32_t val_m;                           \
                                                 \
-       asm volatile (                            \
+       __asm__ volatile (                        \
           "lw  %[val_m],  %[psrc_lw_m]  \n\t"   \
                                                 \
           : [val_m] "=r" (val_m)                \
@ -133,7 +132,7 @@
       uint8_t *pdst_sh_m = (uint8_t *) (pdst);  \
       uint16_t val_m = (val);                   \
                                                 \
-       asm volatile (                            \
+       __asm__ volatile (                        \
           "sh  %[val_m],  %[pdst_sh_m]  \n\t"   \
                                                 \
           : [pdst_sh_m] "=m" (*pdst_sh_m)       \
@ -146,7 +145,7 @@
       uint8_t *pdst_sw_m = (uint8_t *) (pdst);  \
       uint32_t val_m = (val);                   \
                                                 \
-       asm volatile (                            \
+       __asm__ volatile (                        \
           "sw  %[val_m],  %[pdst_sw_m]  \n\t"   \
                                                 \
           : [pdst_sw_m] "=m" (*pdst_sw_m)       \
@ -154,20 +153,20 @@
       );                                        \
   }

-   #if (__mips == 64)
+   #if __mips == 64
        #define SD(val, pdst)                         \
        {                                             \
            uint8_t *pdst_sd_m = (uint8_t *) (pdst);  \
            uint64_t val_m = (val);                   \
                                                      \
-            asm volatile (                            \
+            __asm__ volatile (                        \
                "sd  %[val_m],  %[pdst_sd_m]  \n\t"   \
                                                      \
                : [pdst_sd_m] "=m" (*pdst_sd_m)       \
                : [val_m] "r" (val_m)                 \
            );                                        \
        }
-    #else
+   #else
        #define SD(val, pdst)                                          \
        {                                                              \
            uint8_t *pdst_sd_m = (uint8_t *) (pdst);                   \
@ -179,14 +178,14 @@
            SW(val0_m, pdst_sd_m);                                     \
            SW(val1_m, pdst_sd_m + 4);                                 \
        }
-    #endif
-#else  // !(__mips_isa_rev >= 6)
+   #endif /* __mips == 64 */
+#else
   #define LW(psrc)                              \
   ( {                                           \
       uint8_t *psrc_lw_m = (uint8_t *) (psrc);  \
       uint32_t val_m;                           \
                                                 \
-       asm volatile (                            \
+       __asm__ volatile (                        \
           "ulw  %[val_m],  %[psrc_lw_m]  \n\t"  \
                                                 \
           : [val_m] "=r" (val_m)                \
@ -201,7 +200,7 @@
       uint8_t *pdst_sh_m = (uint8_t *) (pdst);  \
       uint16_t val_m = (val);                   \
                                                 \
-       asm volatile (                            \
+       __asm__ volatile (                        \
           "ush  %[val_m],  %[pdst_sh_m]  \n\t"  \
                                                 \
           : [pdst_sh_m] "=m" (*pdst_sh_m)       \
@ -214,7 +213,7 @@
       uint8_t *pdst_sw_m = (uint8_t *) (pdst);  \
       uint32_t val_m = (val);                   \
                                                 \
-       asm volatile (                            \
+       __asm__ volatile (                        \
           "usw  %[val_m],  %[pdst_sw_m]  \n\t"  \
                                                 \
           : [pdst_sw_m] "=m" (*pdst_sw_m)       \
@ -222,7 +221,7 @@
       );                                        \
   }

-   #define SD(val, pdst)                                          \
+   #define SD(val, pdst)                                           \
    {                                                              \
        uint8_t *pdst_sd_m = (uint8_t *) (pdst);                   \
        uint32_t val0_m, val1_m;                                   \
@ -238,14 +237,14 @@
    {                                          \
        uint8_t *pdst_m = (uint8_t *) (pdst);  \
                                               \
-        asm volatile (                         \
+        __asm__ volatile (                     \
            "usw  $0,  %[pdst_m]  \n\t"        \
                                               \
            : [pdst_m] "=m" (*pdst_m)          \
            :                                  \
        );                                     \
    }
-#endif  // (__mips_isa_rev >= 6)
+#endif /* __mips_isa_rev >= 6 */
 #endif

 #define LD_B(RTYPE, psrc) *((RTYPE *) (psrc))
--- a/mips/mips_init.c
+++ b/mips/mips_init.c
@ -1,4 +1,3 @@
-
 /* mips_init.c - MSA optimised filter functions
 *
 * Copyright (c) 2018-2024 Cosmin Truta
@ -49,7 +48,7 @@ static int png_have_msa(png_structp png_ptr);
 #include PNG_MIPS_MSA_FILE

 #else  /* PNG_MIPS_MSA_FILE */
-#  error "PNG_MIPS_MSA_FILE undefined: no support for run-time MIPS MSA checks"
+#  error PNG_MIPS_MSA_FILE undefined: no support for run-time MIPS MSA checks
 #endif /* PNG_MIPS_MSA_FILE */
 #endif /* PNG_MIPS_MSA_CHECK_SUPPORTED */

@ -67,12 +66,12 @@ static int png_have_mmi();
 #include PNG_MIPS_MMI_FILE

 #else  /* PNG_MIPS_MMI_FILE */
-#  error "PNG_MIPS_MMI_FILE undefined: no support for run-time MIPS MMI checks"
+#  error PNG_MIPS_MMI_FILE undefined: no support for run-time MIPS MMI checks
 #endif /* PNG_MIPS_MMI_FILE */
 #endif /* PNG_MIPS_MMI_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

 /* MIPS supports two optimizations: MMI and MSA. The appropriate
--- a/8
+++ b/8
@ -1,11 +1,11 @@
 #! /bin/sh
 # Common wrapper for a few potentially missing GNU and other programs.

-scriptversion=2024-06-07.14; # UTC
+scriptversion=2025-06-18.21; # UTC

 # shellcheck disable=SC2006,SC2268 # we must support pre-POSIX shells

-# Copyright (C) 1996-2024 Free Software Foundation, Inc.
+# Copyright (C) 1996-2025 Free Software Foundation, Inc.
 # Originally written by Fran,cois Pinard <pinard@iro.umontreal.ca>, 1996.

 # This program is free software; you can redistribute it and/or modify
@ -228,9 +228,9 @@ give_advice "$1" | sed -e '1s/^/WARNING: /' \
 exit $st

 # Local variables:
-# 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/png.5
+++ b/png.5
@ -1,4 +1,4 @@
-.TH PNG 5 "September 12, 2024"
+.TH PNG 5 "July 1, 2025"
 .SH NAME
 png \- Portable Network Graphics (PNG) format

@ -20,15 +20,25 @@ matching on heterogeneous platforms.
 .SH "SEE ALSO"
 .BR "libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
 .LP
+PNG Specification (Third Edition), June 2025:
+.IP
+.br
+https://www.w3.org/TR/2025/REC-png-3-20250624/
+.LP
 PNG Specification (Second Edition), November 2003:
 .IP
 .br
 https://www.w3.org/TR/2003/REC-PNG-20031110/
 .LP
-PNG 1.2 Specification, July 1999:
+PNG 1.2 Specification, August 1999:
 .IP
 .br
-https://png-mng.sourceforge.io/pub/png/spec/1.2/
+https://www.libpng.org/pub/png/spec/1.2/
+.LP
+PNG 1.1 Specification, December 1998:
+.IP
+.br
+https://www.libpng.org/pub/png/spec/1.1/
 .LP
 PNG 1.0 Specification, October 1996:
 .IP
@ -45,15 +55,24 @@ https://www.w3.org/TR/REC-png-961001
 .SH AUTHORS
 This man page: Glenn Randers-Pehrson, Cosmin Truta
 .LP
+Portable Network Graphics (PNG) Specification (Third Edition).
+W3C Recommendation 24 June 2025:
+Chris Blume et al.
+.LP
 Portable Network Graphics (PNG) Specification (Second Edition)
 Information technology - Computer graphics and image processing -
 Portable Network Graphics (PNG): Functional specification.
-ISO/IEC 15948:2003 (E) (November 10, 2003): David Duce and others.
+ISO/IEC 15948:2003 (E), W3C Recommendation 10 November 2003:
+David Duce et al.
 .LP
-Portable Network Graphics (PNG) Specification Version 1.2 (July 8, 1999):
-Glenn Randers-Pehrson and others.
+Portable Network Graphics (PNG) Specification Version 1.2 (11 August 1999):
+Glenn Randers-Pehrson et al.
 .LP
-Portable Network Graphics (PNG) Specification Version 1.0 (October 1, 1996):
-Thomas Boutell and others.
+Portable Network Graphics (PNG) Specification Version 1.1 (31 December 1998):
+Glenn Randers-Pehrson et al.
+.LP
+Portable Network Graphics (PNG) Specification Version 1.0.
+IETF RFC 2083, W3C Recommendation 1 October 1996:
+Thomas Boutell et al.

 .\" end of man page
--- a/png.c
+++ b/png.c
--- a/png.h
+++ b/png.h
@ -1,9 +1,8 @@
-
 /* png.h - header file for PNG reference library
 *
- * libpng version 1.6.44
+ * libpng version 1.6.51.git
 *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
 * Copyright (c) 1996-1997 Andreas Dilger
 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@ -15,7 +14,7 @@
 *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
 *   libpng versions 0.97, January 1998, through 1.6.35, July 2018:
 *     Glenn Randers-Pehrson
- *   libpng versions 1.6.36, December 2018, through 1.6.44, September 2024:
+ *   libpng versions 1.6.36, December 2018, through 1.6.50, July 2025:
 *     Cosmin Truta
 *   See also "Contributing Authors", below.
 */
@ -27,8 +26,8 @@
 * 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.
@ -239,7 +238,7 @@
 *    ...
 *    1.5.30                  15    10530  15.so.15.30[.0]
 *    ...
- *    1.6.44                  16    10644  16.so.16.44[.0]
+ *    1.6.50                  16    10650  16.so.16.50[.0]
 *
 *    Henceforth the source version will match the shared-library major and
 *    minor numbers; the shared-library major version number will be used for
@ -275,7 +274,7 @@
 */

 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.44"
+#define PNG_LIBPNG_VER_STRING "1.6.51.git"
 #define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n"

 /* The versions of shared library builds should stay in sync, going forward */
@ -286,12 +285,12 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 44
+#define PNG_LIBPNG_VER_RELEASE 51

 /* This should be zero for a public release, or non-zero for a
 * development version.
 */
-#define PNG_LIBPNG_VER_BUILD 0
+#define PNG_LIBPNG_VER_BUILD 1

 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA               1
@ -308,7 +307,7 @@
 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
                                       PNG_LIBPNG_BUILD_PRIVATE */

-#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA

 /* Careful here.  At one time, Guy wanted to use 082, but that
 * would be octal.  We must not include leading zeros.
@ -317,7 +316,7 @@
 * From version 1.0.1 it is:
 * XXYYZZ, where XX=major, YY=minor, ZZ=release
 */
-#define PNG_LIBPNG_VER 10644 /* 1.6.44 */
+#define PNG_LIBPNG_VER 10651 /* 1.6.51.git */

 /* Library configuration: these options cannot be changed after
 * the library has been built.
@ -427,7 +426,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
 * do not agree upon the version number.
 */
-typedef char* png_libpng_version_1_6_44;
+typedef char* png_libpng_version_1_6_51_git;

 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
 *
@ -745,6 +744,21 @@ typedef png_unknown_chunk * * png_unknown_chunkpp;
 #define PNG_INFO_sCAL 0x4000U  /* ESR, 1.0.6 */
 #define PNG_INFO_IDAT 0x8000U  /* ESR, 1.0.6 */
 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
+#define PNG_INFO_cICP 0x20000U /* PNGv3: 1.6.45 */
+#define PNG_INFO_cLLI 0x40000U /* PNGv3: 1.6.45 */
+#define PNG_INFO_mDCV 0x80000U /* PNGv3: 1.6.45 */
+/* APNG: these chunks are stored as unknown, these flags are never set
+ * however they are provided as a convenience for implementors of APNG and
+ * avoids any merge conflicts.
+ *
+ * Private chunks: these chunk names violate the chunk name recommendations
+ * because the chunk definitions have no signature and because the private
+ * chunks with these names have been reserved.  Private definitions should
+ * avoid them.
+ */
+#define PNG_INFO_acTL 0x100000U /* PNGv3: 1.6.45: unknown */
+#define PNG_INFO_fcTL 0x200000U /* PNGv3: 1.6.45: unknown */
+#define PNG_INFO_fdAT 0x400000U /* PNGv3: 1.6.45: unknown */

 /* This is used for the transformation routines, as some of them
 * change these values for the row.  It also should enable using
@ -1556,7 +1570,7 @@ PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,

 #ifdef PNG_STDIO_SUPPORTED
 /* Initialize the input/output for the PNG file to the default functions. */
-PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
+PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, FILE *fp));
 #endif

 /* Replace the (error and abort), and warning functions with user
@ -1974,6 +1988,46 @@ PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
    png_fixed_point int_blue_Z))
 #endif

+#ifdef PNG_cICP_SUPPORTED
+PNG_EXPORT(250, png_uint_32, png_get_cICP, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, png_bytep colour_primaries,
+    png_bytep transfer_function, png_bytep matrix_coefficients,
+    png_bytep video_full_range_flag));
+#endif
+
+#ifdef PNG_cICP_SUPPORTED
+PNG_EXPORT(251, void, png_set_cICP, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_byte colour_primaries,
+    png_byte transfer_function, png_byte matrix_coefficients,
+    png_byte video_full_range_flag));
+#endif
+
+#ifdef PNG_cLLI_SUPPORTED
+PNG_FP_EXPORT(252, png_uint_32, png_get_cLLI, (png_const_structrp png_ptr,
+         png_const_inforp info_ptr, double *maximum_content_light_level,
+         double *maximum_frame_average_light_level))
+PNG_FIXED_EXPORT(253, png_uint_32, png_get_cLLI_fixed,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr,
+    /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
+     * 100,000 as in the case of png_fixed_point.
+     */
+    png_uint_32p maximum_content_light_level_scaled_by_10000,
+    png_uint_32p maximum_frame_average_light_level_scaled_by_10000))
+#endif
+
+#ifdef PNG_cLLI_SUPPORTED
+PNG_FP_EXPORT(254, void, png_set_cLLI, (png_const_structrp png_ptr,
+         png_inforp info_ptr, double maximum_content_light_level,
+         double maximum_frame_average_light_level))
+PNG_FIXED_EXPORT(255, void, png_set_cLLI_fixed, (png_const_structrp png_ptr,
+    png_inforp info_ptr,
+    /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
+     * 100,000 as in the case of png_fixed_point.
+     */
+    png_uint_32 maximum_content_light_level_scaled_by_10000,
+    png_uint_32 maximum_frame_average_light_level_scaled_by_10000))
+#endif
+
 #ifdef PNG_eXIf_SUPPORTED
 PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
    png_inforp info_ptr, png_bytep *exif));
@ -2018,6 +2072,60 @@ PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
    int color_type, int interlace_method, int compression_method,
    int filter_method));

+#ifdef PNG_mDCV_SUPPORTED
+PNG_FP_EXPORT(256, png_uint_32, png_get_mDCV, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr,
+    /* The chromaticities of the mastering display.  As cHRM, but independent of
+     * the encoding endpoints in cHRM, or cICP, or iCCP.  These values will
+     * always be in the range 0 to 1.3107.
+     */
+    double *white_x, double *white_y, double *red_x, double *red_y,
+    double *green_x, double *green_y, double *blue_x, double *blue_y,
+    /* Mastering display luminance in cd/m2 (nits). */
+    double *mastering_display_maximum_luminance,
+    double *mastering_display_minimum_luminance))
+
+PNG_FIXED_EXPORT(257, png_uint_32, png_get_mDCV_fixed,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *int_white_x, png_fixed_point *int_white_y,
+    png_fixed_point *int_red_x, png_fixed_point *int_red_y,
+    png_fixed_point *int_green_x, png_fixed_point *int_green_y,
+    png_fixed_point *int_blue_x, png_fixed_point *int_blue_y,
+    /* Mastering display luminance in cd/m2 (nits) multiplied (scaled) by
+     * 10,000.
+     */
+    png_uint_32p mastering_display_maximum_luminance_scaled_by_10000,
+    png_uint_32p mastering_display_minimum_luminance_scaled_by_10000))
+#endif
+
+#ifdef PNG_mDCV_SUPPORTED
+PNG_FP_EXPORT(258, void, png_set_mDCV, (png_const_structrp png_ptr,
+    png_inforp info_ptr,
+    /* The chromaticities of the mastering display.  As cHRM, but independent of
+     * the encoding endpoints in cHRM, or cICP, or iCCP.
+     */
+    double white_x, double white_y, double red_x, double red_y, double green_x,
+    double green_y, double blue_x, double blue_y,
+    /* Mastering display luminance in cd/m2 (nits). */
+    double mastering_display_maximum_luminance,
+    double mastering_display_minimum_luminance))
+
+PNG_FIXED_EXPORT(259, void, png_set_mDCV_fixed, (png_const_structrp png_ptr,
+    png_inforp info_ptr,
+    /* The admissible range of these values is not the full range of a PNG
+     * fixed point value.  Negative values cannot be encoded and the maximum
+     * value is about 1.3 */
+    png_fixed_point int_white_x, png_fixed_point int_white_y,
+    png_fixed_point int_red_x, png_fixed_point int_red_y,
+    png_fixed_point int_green_x, png_fixed_point int_green_y,
+    png_fixed_point int_blue_x, png_fixed_point int_blue_y,
+    /* These are PNG unsigned 4 byte values: 31-bit unsigned values.  The MSB
+     * must be zero.
+     */
+    png_uint_32 mastering_display_maximum_luminance_scaled_by_10000,
+    png_uint_32 mastering_display_minimum_luminance_scaled_by_10000))
+#endif
+
 #ifdef PNG_oFFs_SUPPORTED
 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
   png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
@ -2980,7 +3088,7 @@ PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
    */

 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
-   FILE* file));
+   FILE *file));
   /* The PNG header is read from the stdio FILE object. */
 #endif /* STDIO */

@ -3055,7 +3163,7 @@ PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
   int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
   const void *colormap));
-   /* Write the image to the given (FILE*). */
+   /* Write the image to the given FILE object. */
 #endif /* SIMPLIFIED_WRITE_STDIO */

 /* With all write APIs if image is in one of the linear formats with 16-bit
@ -3195,26 +3303,45 @@ PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
 *           selected at run time.
 */
 #ifdef PNG_SET_OPTION_SUPPORTED
+
+/* HARDWARE: ARM Neon SIMD instructions supported */
 #ifdef PNG_ARM_NEON_API_SUPPORTED
-#  define PNG_ARM_NEON   0 /* HARDWARE: ARM Neon SIMD instructions supported */
-#endif
-#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
-#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
-#ifdef PNG_MIPS_MSA_API_SUPPORTED
-#  define PNG_MIPS_MSA   6 /* HARDWARE: MIPS Msa SIMD instructions supported */
-#endif
-#ifdef PNG_DISABLE_ADLER32_CHECK_SUPPORTED
-#  define PNG_IGNORE_ADLER32 8 /* SOFTWARE: disable Adler32 check on IDAT */
-#endif
-#ifdef PNG_POWERPC_VSX_API_SUPPORTED
-#  define PNG_POWERPC_VSX   10 /* HARDWARE: PowerPC VSX SIMD instructions
-                                * supported */
-#endif
-#ifdef PNG_MIPS_MMI_API_SUPPORTED
-#  define PNG_MIPS_MMI   12 /* HARDWARE: MIPS MMI SIMD instructions supported */
+#  define PNG_ARM_NEON 0
 #endif

-#define PNG_OPTION_NEXT  14 /* Next option - numbers must be even */
+/* SOFTWARE: Force maximum window */
+#define PNG_MAXIMUM_INFLATE_WINDOW 2
+
+/* SOFTWARE: Check ICC profile for sRGB */
+#define PNG_SKIP_sRGB_CHECK_PROFILE 4
+
+/* HARDWARE: MIPS MSA SIMD instructions supported */
+#ifdef PNG_MIPS_MSA_API_SUPPORTED
+#  define PNG_MIPS_MSA 6
+#endif
+
+/* SOFTWARE: Disable Adler32 check on IDAT */
+#ifdef PNG_DISABLE_ADLER32_CHECK_SUPPORTED
+#  define PNG_IGNORE_ADLER32 8
+#endif
+
+/* HARDWARE: PowerPC VSX SIMD instructions supported */
+#ifdef PNG_POWERPC_VSX_API_SUPPORTED
+#  define PNG_POWERPC_VSX 10
+#endif
+
+/* HARDWARE: MIPS MMI SIMD instructions supported */
+#ifdef PNG_MIPS_MMI_API_SUPPORTED
+#  define PNG_MIPS_MMI 12
+#endif
+
+/* HARDWARE: RISC-V RVV SIMD instructions supported */
+#ifdef PNG_RISCV_RVV_API_SUPPORTED
+#  define PNG_RISCV_RVV 14
+#endif
+
+/* Next option - numbers must be even */
+#define PNG_OPTION_NEXT 16

 /* Return values: NOTE: there are four values and 'off' is *not* zero */
 #define PNG_OPTION_UNSET   0 /* Unset - defaults to off */
@ -3238,7 +3365,7 @@ PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
 * one to use is one more than this.)
 */
 #ifdef PNG_EXPORT_LAST_ORDINAL
-  PNG_EXPORT_LAST_ORDINAL(249);
+  PNG_EXPORT_LAST_ORDINAL(259);
 #endif

 #ifdef __cplusplus
--- a/pngconf.h
+++ b/pngconf.h
@ -1,9 +1,8 @@
-
 /* pngconf.h - machine-configurable file for libpng
 *
- * libpng version 1.6.44
+ * libpng version 1.6.51.git
 *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
 * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
 * Copyright (c) 1996-1997 Andreas Dilger
 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@ -220,25 +219,13 @@
  /* NOTE: PNGCBAPI always defaults to PNGCAPI. */

 #  if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
-#     error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed"
+#     error PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed
 #  endif

-#  if (defined(_MSC_VER) && _MSC_VER < 800) ||\
-      (defined(__BORLANDC__) && __BORLANDC__ < 0x500)
-   /* older Borland and MSC
-    * compilers used '__export' and required this to be after
-    * the type.
-    */
-#    ifndef PNG_EXPORT_TYPE
-#      define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
-#    endif
-#    define PNG_DLL_EXPORT __export
-#  else /* newer compiler */
-#    define PNG_DLL_EXPORT __declspec(dllexport)
-#    ifndef PNG_DLL_IMPORT
-#      define PNG_DLL_IMPORT __declspec(dllimport)
-#    endif
-#  endif /* compiler */
+#  define PNG_DLL_EXPORT __declspec(dllexport)
+#  ifndef PNG_DLL_IMPORT
+#    define PNG_DLL_IMPORT __declspec(dllimport)
+#  endif

 #else /* !Windows */
 #  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
@ -480,7 +467,7 @@
 #if CHAR_BIT == 8 && UCHAR_MAX == 255
   typedef unsigned char png_byte;
 #else
-#  error "libpng requires 8-bit bytes"
+#  error libpng requires 8-bit bytes
 #endif

 #if INT_MIN == -32768 && INT_MAX == 32767
@ -488,7 +475,7 @@
 #elif SHRT_MIN == -32768 && SHRT_MAX == 32767
   typedef short png_int_16;
 #else
-#  error "libpng requires a signed 16-bit type"
+#  error libpng requires a signed 16-bit integer type
 #endif

 #if UINT_MAX == 65535
@ -496,7 +483,7 @@
 #elif USHRT_MAX == 65535
   typedef unsigned short png_uint_16;
 #else
-#  error "libpng requires an unsigned 16-bit type"
+#  error libpng requires an unsigned 16-bit integer type
 #endif

 #if INT_MIN < -2147483646 && INT_MAX > 2147483646
@ -504,7 +491,7 @@
 #elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
   typedef long int png_int_32;
 #else
-#  error "libpng requires a signed 32-bit (or more) type"
+#  error libpng requires a signed 32-bit (or longer) integer type
 #endif

 #if UINT_MAX > 4294967294U
@ -512,7 +499,7 @@
 #elif ULONG_MAX > 4294967294U
   typedef unsigned long int png_uint_32;
 #else
-#  error "libpng requires an unsigned 32-bit (or more) type"
+#  error libpng requires an unsigned 32-bit (or longer) integer type
 #endif

 /* Prior to 1.6.0, it was possible to disable the use of size_t and ptrdiff_t.
@ -593,10 +580,6 @@ typedef const png_fixed_point * png_const_fixed_point_p;
 typedef size_t                * png_size_tp;
 typedef const size_t          * png_const_size_tp;

-#ifdef PNG_STDIO_SUPPORTED
-typedef FILE            * png_FILE_p;
-#endif
-
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 typedef double       * png_doublep;
 typedef const double * png_const_doublep;
@ -618,6 +601,15 @@ typedef double          * * png_doublepp;
 /* Pointers to pointers to pointers; i.e., pointer to array */
 typedef char            * * * png_charppp;

+#ifdef PNG_STDIO_SUPPORTED
+/* With PNG_STDIO_SUPPORTED it was possible to use I/O streams that were
+ * not necessarily stdio FILE streams, to allow building Windows applications
+ * before Win32 and Windows CE applications before WinCE 3.0, but that kind
+ * of support has long been discontinued.
+ */
+typedef FILE            * png_FILE_p; /* [Deprecated] */
+#endif
+
 #endif /* PNG_BUILDING_SYMBOL_TABLE */

 #endif /* PNGCONF_H */
--- a/pngdebug.h
+++ b/pngdebug.h
@ -1,7 +1,6 @@
-
-/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
+/* pngdebug.h - internal debugging macros for libpng
 *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
 * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson
 * Copyright (c) 1996-1997 Andreas Dilger
 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@ -11,6 +10,10 @@
 * and license in png.h
 */

+#ifndef PNGPRIV_H
+#  error This file must not be included by applications; please include <png.h>
+#endif
+
 /* Define PNG_DEBUG at compile time for debugging information.  Higher
 * numbers for PNG_DEBUG mean more debugging information.  This has
 * only been added since version 0.95 so it is not implemented throughout
--- a/pngerror.c
+++ b/pngerror.c
@ -1,7 +1,6 @@
-
 /* pngerror.c - stub functions for i/o and memory allocation
 *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
 * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
 * Copyright (c) 1996-1997 Andreas Dilger
 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@ -936,23 +935,37 @@ png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
 int /* PRIVATE */
 png_safe_execute(png_imagep image, int (*function)(png_voidp), png_voidp arg)
 {
-   png_voidp saved_error_buf = image->opaque->error_buf;
+   const png_voidp saved_error_buf = image->opaque->error_buf;
   jmp_buf safe_jmpbuf;
-   int result;

   /* Safely execute function(arg), with png_error returning back here. */
   if (setjmp(safe_jmpbuf) == 0)
   {
+      int result;
+
      image->opaque->error_buf = safe_jmpbuf;
      result = function(arg);
      image->opaque->error_buf = saved_error_buf;
-      return result;
+
+      if (result)
+         return 1; /* success */
   }

-   /* On png_error, return via longjmp, pop the jmpbuf, and free the image. */
+   /* The function failed either because of a caught png_error and a regular
+    * return of false above or because of an uncaught png_error from the
+    * function itself.  Ensure that the error_buf is always set back to the
+    * value saved above:
+    */
   image->opaque->error_buf = saved_error_buf;
-   png_image_free(image);
-   return 0;
+
+   /* On the final false return, when about to return control to the caller, the
+    * image is freed (png_image_free does this check but it is duplicated here
+    * for clarity:
+    */
+   if (saved_error_buf == NULL)
+      png_image_free(image);
+
+   return 0; /* failure */
 }
 #endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */
 #endif /* READ || WRITE */
--- a/pngget.c
+++ b/pngget.c
@ -1,7 +1,6 @@
-
 /* pngget.c - retrieval of values from info struct
 *
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 Cosmin Truta
 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
 * Copyright (c) 1996-1997 Andreas Dilger
 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@ -381,7 +380,13 @@ png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns)
    * Notice that this can overflow - a warning is output and 0 is
    * returned.
    */
-   return png_muldiv_warn(png_ptr, microns, 500, 127);
+   png_fixed_point result;
+
+   if (png_muldiv(&result, microns, 500, 127) != 0)
+      return result;
+
+   png_warning(png_ptr, "fixed point overflow ignored");
+   return 0;
 }

 png_fixed_point PNGAPI
@ -391,7 +396,7 @@ png_get_x_offset_inches_fixed(png_const_structrp png_ptr,
   return png_fixed_inches_from_microns(png_ptr,
       png_get_x_offset_microns(png_ptr, info_ptr));
 }
-#endif
+#endif /* FIXED_POINT */

 #ifdef PNG_FIXED_POINT_SUPPORTED
 png_fixed_point PNGAPI
@ -519,44 +524,31 @@ png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32 PNGAPI
 png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
-    double *white_x, double *white_y, double *red_x, double *red_y,
-    double *green_x, double *green_y, double *blue_x, double *blue_y)
+    double *whitex, double *whitey, double *redx, double *redy,
+    double *greenx, double *greeny, double *bluex, double *bluey)
 {
   png_debug1(1, "in %s retrieval function", "cHRM");

-   /* Quiet API change: this code used to only return the end points if a cHRM
-    * chunk was present, but the end points can also come from iCCP or sRGB
-    * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and
-    * the png_set_ APIs merely check that set end points are mutually
-    * consistent.
-    */
+   /* PNGv3: this just returns the values store from the cHRM, if any. */
   if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+       (info_ptr->valid & PNG_INFO_cHRM) != 0)
   {
-      if (white_x != NULL)
-         *white_x = png_float(png_ptr,
-             info_ptr->colorspace.end_points_xy.whitex, "cHRM white X");
-      if (white_y != NULL)
-         *white_y = png_float(png_ptr,
-             info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y");
-      if (red_x != NULL)
-         *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx,
-             "cHRM red X");
-      if (red_y != NULL)
-         *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy,
-             "cHRM red Y");
-      if (green_x != NULL)
-         *green_x = png_float(png_ptr,
-             info_ptr->colorspace.end_points_xy.greenx, "cHRM green X");
-      if (green_y != NULL)
-         *green_y = png_float(png_ptr,
-             info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y");
-      if (blue_x != NULL)
-         *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex,
-             "cHRM blue X");
-      if (blue_y != NULL)
-         *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey,
-             "cHRM blue Y");
+      if (whitex != NULL)
+         *whitex = png_float(png_ptr, info_ptr->cHRM.whitex, "cHRM wx");
+      if (whitey != NULL)
+         *whitey = png_float(png_ptr, info_ptr->cHRM.whitey, "cHRM wy");
+      if (redx   != NULL)
+         *redx   = png_float(png_ptr, info_ptr->cHRM.redx,   "cHRM rx");
+      if (redy   != NULL)
+         *redy   = png_float(png_ptr, info_ptr->cHRM.redy,   "cHRM ry");
+      if (greenx != NULL)
+         *greenx = png_float(png_ptr, info_ptr->cHRM.greenx, "cHRM gx");
+      if (greeny != NULL)
+         *greeny = png_float(png_ptr, info_ptr->cHRM.greeny, "cHRM gy");
+      if (bluex  != NULL)
+         *bluex  = png_float(png_ptr, info_ptr->cHRM.bluex,  "cHRM bx");
+      if (bluey  != NULL)
+         *bluey  = png_float(png_ptr, info_ptr->cHRM.bluey,  "cHRM by");
      return PNG_INFO_cHRM;
   }

@ -569,38 +561,31 @@ png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
    double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
    double *blue_Z)
 {
+   png_XYZ XYZ;
   png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");

   if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+       (info_ptr->valid & PNG_INFO_cHRM) != 0 &&
+       png_XYZ_from_xy(&XYZ, &info_ptr->cHRM) == 0)
   {
      if (red_X != NULL)
-         *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
-             "cHRM red X");
+         *red_X = png_float(png_ptr, XYZ.red_X, "cHRM red X");
      if (red_Y != NULL)
-         *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y,
-             "cHRM red Y");
+         *red_Y = png_float(png_ptr, XYZ.red_Y, "cHRM red Y");
      if (red_Z != NULL)
-         *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
-             "cHRM red Z");
+         *red_Z = png_float(png_ptr, XYZ.red_Z, "cHRM red Z");
      if (green_X != NULL)
-         *green_X = png_float(png_ptr,
-             info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X");
+         *green_X = png_float(png_ptr, XYZ.green_X, "cHRM green X");
      if (green_Y != NULL)
-         *green_Y = png_float(png_ptr,
-             info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y");
+         *green_Y = png_float(png_ptr, XYZ.green_Y, "cHRM green Y");
      if (green_Z != NULL)
-         *green_Z = png_float(png_ptr,
-             info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z");
+         *green_Z = png_float(png_ptr, XYZ.green_Z, "cHRM green Z");
      if (blue_X != NULL)
-         *blue_X = png_float(png_ptr,
-             info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X");
+         *blue_X = png_float(png_ptr, XYZ.blue_X, "cHRM blue X");
      if (blue_Y != NULL)
-         *blue_Y = png_float(png_ptr,
-             info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y");
+         *blue_Y = png_float(png_ptr, XYZ.blue_Y, "cHRM blue Y");
      if (blue_Z != NULL)
-         *blue_Z = png_float(png_ptr,
-             info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z");
+         *blue_Z = png_float(png_ptr, XYZ.blue_Z, "cHRM blue Z");
      return PNG_INFO_cHRM;
   }

@ -617,29 +602,22 @@ png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
    png_fixed_point *int_blue_Z)
 {
+   png_XYZ XYZ;
   png_debug1(1, "in %s retrieval function", "cHRM_XYZ");

   if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+       (info_ptr->valid & PNG_INFO_cHRM) != 0U &&
+       png_XYZ_from_xy(&XYZ, &info_ptr->cHRM) == 0)
   {
-      if (int_red_X != NULL)
-         *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X;
-      if (int_red_Y != NULL)
-         *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y;
-      if (int_red_Z != NULL)
-         *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z;
-      if (int_green_X != NULL)
-         *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X;
-      if (int_green_Y != NULL)
-         *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y;
-      if (int_green_Z != NULL)
-         *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z;
-      if (int_blue_X != NULL)
-         *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X;
-      if (int_blue_Y != NULL)
-         *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y;
-      if (int_blue_Z != NULL)
-         *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z;
+      if (int_red_X != NULL) *int_red_X = XYZ.red_X;
+      if (int_red_Y != NULL) *int_red_Y = XYZ.red_Y;
+      if (int_red_Z != NULL) *int_red_Z = XYZ.red_Z;
+      if (int_green_X != NULL) *int_green_X = XYZ.green_X;
+      if (int_green_Y != NULL) *int_green_Y = XYZ.green_Y;
+      if (int_green_Z != NULL) *int_green_Z = XYZ.green_Z;
+      if (int_blue_X != NULL) *int_blue_X = XYZ.blue_X;
+      if (int_blue_Y != NULL) *int_blue_Y = XYZ.blue_Y;
+      if (int_blue_Z != NULL) *int_blue_Z = XYZ.blue_Z;
      return PNG_INFO_cHRM;
   }

@ -648,31 +626,24 @@ png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,

 png_uint_32 PNGAPI
 png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
-    png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
-    png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
-    png_fixed_point *blue_x, png_fixed_point *blue_y)
+    png_fixed_point *whitex, png_fixed_point *whitey, png_fixed_point *redx,
+    png_fixed_point *redy, png_fixed_point *greenx, png_fixed_point *greeny,
+    png_fixed_point *bluex, png_fixed_point *bluey)
 {
   png_debug1(1, "in %s retrieval function", "cHRM");

+   /* PNGv3: this just returns the values store from the cHRM, if any. */
   if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+       (info_ptr->valid & PNG_INFO_cHRM) != 0)
   {
-      if (white_x != NULL)
-         *white_x = info_ptr->colorspace.end_points_xy.whitex;
-      if (white_y != NULL)
-         *white_y = info_ptr->colorspace.end_points_xy.whitey;
-      if (red_x != NULL)
-         *red_x = info_ptr->colorspace.end_points_xy.redx;
-      if (red_y != NULL)
-         *red_y = info_ptr->colorspace.end_points_xy.redy;
-      if (green_x != NULL)
-         *green_x = info_ptr->colorspace.end_points_xy.greenx;
-      if (green_y != NULL)
-         *green_y = info_ptr->colorspace.end_points_xy.greeny;
-      if (blue_x != NULL)
-         *blue_x = info_ptr->colorspace.end_points_xy.bluex;
-      if (blue_y != NULL)
-         *blue_y = info_ptr->colorspace.end_points_xy.bluey;
+      if (whitex != NULL) *whitex = info_ptr->cHRM.whitex;
+      if (whitey != NULL) *whitey = info_ptr->cHRM.whitey;
+      if (redx   != NULL) *redx   = info_ptr->cHRM.redx;
+      if (redy   != NULL) *redy   = info_ptr->cHRM.redy;
+      if (greenx != NULL) *greenx = info_ptr->cHRM.greenx;
+      if (greeny != NULL) *greeny = info_ptr->cHRM.greeny;
+      if (bluex  != NULL) *bluex  = info_ptr->cHRM.bluex;
+      if (bluey  != NULL) *bluey  = info_ptr->cHRM.bluey;
      return PNG_INFO_cHRM;
   }

@ -689,11 +660,11 @@ png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
   png_debug1(1, "in %s retrieval function", "gAMA");

+   /* PNGv3 compatibility: only report gAMA if it is really present. */
   if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
-       file_gamma != NULL)
+       (info_ptr->valid & PNG_INFO_gAMA) != 0)
   {
-      *file_gamma = info_ptr->colorspace.gamma;
+      if (file_gamma != NULL) *file_gamma = info_ptr->gamma;
      return PNG_INFO_gAMA;
   }

@ -708,12 +679,13 @@ png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
   png_debug1(1, "in %s retrieval function", "gAMA(float)");

+   /* PNGv3 compatibility: only report gAMA if it is really present. */
   if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
-      file_gamma != NULL)
+       (info_ptr->valid & PNG_INFO_gAMA) != 0)
   {
-      *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma,
-          "png_get_gAMA");
+      if (file_gamma != NULL)
+         *file_gamma = png_float(png_ptr, info_ptr->gamma, "gAMA");
+
      return PNG_INFO_gAMA;
   }

@ -730,9 +702,10 @@ png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
   png_debug1(1, "in %s retrieval function", "sRGB");

   if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->valid & PNG_INFO_sRGB) != 0 && file_srgb_intent != NULL)
+      (info_ptr->valid & PNG_INFO_sRGB) != 0)
   {
-      *file_srgb_intent = info_ptr->colorspace.rendering_intent;
+      if (file_srgb_intent != NULL)
+         *file_srgb_intent = info_ptr->rendering_intent;
      return PNG_INFO_sRGB;
   }

@ -785,6 +758,136 @@ png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
 }
 #endif

+#ifdef PNG_cICP_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cICP(png_const_structrp png_ptr,
+             png_const_inforp info_ptr, png_bytep colour_primaries,
+             png_bytep transfer_function, png_bytep matrix_coefficients,
+             png_bytep video_full_range_flag)
+{
+    png_debug1(1, "in %s retrieval function", "cICP");
+
+    if (png_ptr != NULL && info_ptr != NULL &&
+        (info_ptr->valid & PNG_INFO_cICP) != 0 &&
+        colour_primaries != NULL && transfer_function != NULL &&
+        matrix_coefficients != NULL && video_full_range_flag != NULL)
+    {
+        *colour_primaries = info_ptr->cicp_colour_primaries;
+        *transfer_function = info_ptr->cicp_transfer_function;
+        *matrix_coefficients = info_ptr->cicp_matrix_coefficients;
+        *video_full_range_flag = info_ptr->cicp_video_full_range_flag;
+        return (PNG_INFO_cICP);
+    }
+
+    return 0;
+}
+#endif
+
+#ifdef PNG_cLLI_SUPPORTED
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cLLI_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_uint_32p maxCLL,
+    png_uint_32p maxFALL)
+{
+   png_debug1(1, "in %s retrieval function", "cLLI");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_cLLI) != 0)
+   {
+      if (maxCLL != NULL) *maxCLL = info_ptr->maxCLL;
+      if (maxFALL != NULL) *maxFALL = info_ptr->maxFALL;
+      return PNG_INFO_cLLI;
+   }
+
+   return 0;
+}
+#  endif
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cLLI(png_const_structrp png_ptr, png_const_inforp info_ptr,
+      double *maxCLL, double *maxFALL)
+{
+   png_debug1(1, "in %s retrieval function", "cLLI(float)");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_cLLI) != 0)
+   {
+      if (maxCLL != NULL) *maxCLL = info_ptr->maxCLL * .0001;
+      if (maxFALL != NULL) *maxFALL = info_ptr->maxFALL * .0001;
+      return PNG_INFO_cLLI;
+   }
+
+   return 0;
+}
+#  endif
+#endif /* cLLI */
+
+#ifdef PNG_mDCV_SUPPORTED
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_mDCV_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *white_x, png_fixed_point *white_y,
+    png_fixed_point *red_x, png_fixed_point *red_y,
+    png_fixed_point *green_x, png_fixed_point *green_y,
+    png_fixed_point *blue_x, png_fixed_point *blue_y,
+    png_uint_32p mastering_maxDL, png_uint_32p mastering_minDL)
+{
+   png_debug1(1, "in %s retrieval function", "mDCV");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_mDCV) != 0)
+   {
+      if (white_x != NULL) *white_x = info_ptr->mastering_white_x * 2;
+      if (white_y != NULL) *white_y = info_ptr->mastering_white_y * 2;
+      if (red_x != NULL) *red_x = info_ptr->mastering_red_x * 2;
+      if (red_y != NULL) *red_y = info_ptr->mastering_red_y * 2;
+      if (green_x != NULL) *green_x = info_ptr->mastering_green_x * 2;
+      if (green_y != NULL) *green_y = info_ptr->mastering_green_y * 2;
+      if (blue_x != NULL) *blue_x = info_ptr->mastering_blue_x * 2;
+      if (blue_y != NULL) *blue_y = info_ptr->mastering_blue_y * 2;
+      if (mastering_maxDL != NULL) *mastering_maxDL = info_ptr->mastering_maxDL;
+      if (mastering_minDL != NULL) *mastering_minDL = info_ptr->mastering_minDL;
+      return PNG_INFO_mDCV;
+   }
+
+   return 0;
+}
+#  endif
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_mDCV(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    double *white_x, double *white_y, double *red_x, double *red_y,
+    double *green_x, double *green_y, double *blue_x, double *blue_y,
+    double *mastering_maxDL, double *mastering_minDL)
+{
+   png_debug1(1, "in %s retrieval function", "mDCV(float)");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_mDCV) != 0)
+   {
+      if (white_x != NULL) *white_x = info_ptr->mastering_white_x * .00002;
+      if (white_y != NULL) *white_y = info_ptr->mastering_white_y * .00002;
+      if (red_x != NULL) *red_x = info_ptr->mastering_red_x * .00002;
+      if (red_y != NULL) *red_y = info_ptr->mastering_red_y * .00002;
+      if (green_x != NULL) *green_x = info_ptr->mastering_green_x * .00002;
+      if (green_y != NULL) *green_y = info_ptr->mastering_green_y * .00002;
+      if (blue_x != NULL) *blue_x = info_ptr->mastering_blue_x * .00002;
+      if (blue_y != NULL) *blue_y = info_ptr->mastering_blue_y * .00002;
+      if (mastering_maxDL != NULL)
+         *mastering_maxDL = info_ptr->mastering_maxDL * .0001;
+      if (mastering_minDL != NULL)
+         *mastering_minDL = info_ptr->mastering_minDL * .0001;
+      return PNG_INFO_mDCV;
+   }
+
+   return 0;
+}
+#  endif /* FLOATING_POINT */
+#endif /* mDCV */
+
 #ifdef PNG_eXIf_SUPPORTED
 png_uint_32 PNGAPI
 png_get_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
--- a/Show More
+++ b/Show More
				`@ -1,2 +1 @@`

				`These images fail the "pngimage-quick" and "pngimage-full" tests.`