[libpng17] Use a more generous size limit for IDAT chunks.

parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.7.0beta80 - May 6, 2016
+Libpng 1.7.0beta90 - September 3, 2017
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -9,20 +9,20 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.7.0beta80.tar.xz (LZMA-compressed, recommended)
-   1.7.0beta80.tar.gz
+   1.7.0beta90.tar.xz (LZMA-compressed, recommended)
+   1.7.0beta90.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   /scratch/glennrp/Libpng17/lp170b80.7z  (LZMA-compressed, recommended)
-   /scratch/glennrp/Libpng17/lp170b80.zip
+   /scratch/glennrp/Libpng17/lp170b90.7z  (LZMA-compressed, recommended)
+   /scratch/glennrp/Libpng17/lp170b90.zip
 
 Other information:
 
-   1.7.0beta80-README.txt
-   1.7.0beta80-LICENSE.txt
-   libpng-1.7.0beta80-*.asc (armored detached GPG signatures)
+   1.7.0beta90-README.txt
+   1.7.0beta90-LICENSE.txt
+   libpng-1.7.0beta90-*.asc (armored detached GPG signatures)
 
 Changes since the last public release (1.6.0):
 
@@ -1290,6 +1290,161 @@ Version 1.7.0beta80 [May 6, 2016]
       unreachable code in pz_default_settings and eliminated a spurious
       warning in pngcp for small files.
 
+Version 1.7.0beta81 [June 11, 2016]
+  Check for CLOCK_PROCESS_CPUTIME_ID when building /contrib/libtests/timepng.
+    Otherwise it does not build on platforms that don't supply clock_gettime().
+  Add check for clock_gettime() in Makefile.am and configure.ac
+  Reenabled filter selection (dummy).  This implements the code for
+    row-by-row filter selection but does not provide an actual implementation;
+    the selection function just chooses the lowest set filter bit.
+  Fixed a signed/unsigned warning (GCC 4.8.5) in pngwutil.c
+  Implemented base filter selection with row buffering and a crude code-count
+    algorithm.
+  Added filter selection, palette index checks.  Palette index checking:
+    checking on read was erroneously skipped.  pngcp can now turn off the
+    palette index checking or fix the errors (mainly to allow comparison with
+    libpng 1.6, which defaulted to ignoring it).  The API now documents how
+    the 'enabled' parameter works.  On read the check is on by default (it
+    was apparently off in libpng 1.6) however now if explicitly turned on the
+    warning message is stopped; this provides better interaction with
+    get_palette_max at the cost of a small API change (may need to be reviewed.)
+  Palette size errors: invalid entries in the palette are now set to #beaded to
+    make the errors more obvious and allow easy detection in memory.
+  Read transform pipeline caching: changes to fix the palette index check
+    (which are erroneously cached), the pipeline can now contain multiple
+    caches, e.g., caching of packing of palette indices can be combined with
+    caching of palette RGB transforms.
+  Read code now checks for callbacks to read 0 data (and faults them).
+    Fixed the reading of PNGs with multiple 0 length IDATs that failed as a
+    result plus the handling of zero length unknown (which occurs, validly;
+    the spurious warning has been removed).
+  Filter selection: the 1.6 and earlier sum of absolute differences algorithm
+    has been reintroduced with an option to disfavor some filters over others
+    where the sums are close (not yet exposed).  The selection code also logs
+    the last known occurence of each possible byte code across multiple lines.
+    This allows detection of PNG images with lower bit depth than the format
+    implies and, therefore, allows the filtering to be turned off in those
+    cases as well.
+  The default write zlib settings are still lower than libpng16.  The
+    selection algorithm is being refined (the overall results are worse than
+    not doing any filtering).
+  Port contrib/libtests/pngvalid.c from libpng16.
+  PNG compression level setting API: this allows the various compression
+    settings controlling deflate, fitlering, and so on to be set via a single
+    setting with six values.  This is currently documented in png.h ("Write
+    compression settings").
+  Internally the compression settings have been tuned both for the overall
+    setting and for any specific settings made by the original APIs.
+  APIs to control iCCP chunk compression separately have been added.
+  contrib/examples/pngcp.c has been modified to accomodate the new compression
+    setting and to include options for separate control of iCCP chunk
+    compression.
+  The new "png_setting" ABI has been modified to accomodate a wider range of
+    settings and most of the old compression control ABIs have been replaced by
+    function-like macros with the same API which call png_setting.  This is an
+    API check in 1.7.0 for png_setting (alone).  png_setting now handles all
+    of png_set_option.  This eliminates 19 ABIs at the cost of adding 1
+    (png_setting).
+  CRC and benign error checking has been updated internally to use bit-fields
+    and the CRC calculation skip when the CRC is not used has been improved
+    slightly to avoid the initialization of the CRC.  A new png_setting based
+    API allows more detailed control of benign error/warning messages (this
+    may change, the internal error handling seems too complex.)  The
+    ERROR_NUMBERS support has been removed with the intent of implementing
+    proper i18n.
+  The memcpy-size-0 issue in png_push_fill_buffer has been fixed, with an
+    appropriate debug() assert if a fill for 0 bytes occurs.
+  Most PNG_FLAG_ values for png_struct::flags have been eliminated (as a
+    result of the benign error handling changes).  Only one remains.
+  The LOW_MEMORY PNG_COMPRESSION option should not be setting HUFFMAN_ONLY or
+    using a low deflate 'level'; according to the comments in zconf.h only
+    windowBits and memLevel affect the memory.  pngwutil.c has been changed
+    to use the same values as HIGH compression.
+  The COMPAT option turned on the old optimize_cmf code (now in fix_cinfo),
+    however there was a serious bug in that code; it put the wrong value in
+    z_cmf.  The setting was also not handled correctly in
+    pz_compression_settings.
+  pngtest now verifies the operation of COMPAT and, as a result, pngtest.png
+    has been reverted to the libpng 1.6 (etc) version.
+  IDAT size handling has been improved; if not explicitly set values
+    appropriate to png_level are now chosen (in addition to the handling for
+    the COMPAT setting).  HIGH and HIGH_READ_SPEED now create unlimited
+    (up to the PNG chunk-size limit of 2^31-1 bytes) size IDAT chunks,
+    which requires buffering the whole of the IDAT data in memory but
+    reflects what other programs and optimizers do.
+  Changed handling of PNG_IMAGE_FLAG_FAST in the simplified API to use
+    PNG_COMPRESSION_HIGH_SPEED, and PNG_COMPRESSION_HIGH otherwise.
+  Removed png_struct::flags which is no longer used.
+  Fixed implementations of png_app_error() and png_app_warning() which
+    previously were swapped.
+  Avoid potential overflow of the PNG_IMAGE_SIZE macro.  This macro
+    is not used within libpng, but is used in some of the examples.
+
+Version 1.7.0beta82 [July 4, 2016]
+  Put the SKIP definition in the correct place. It needs to come after the
+    png.h include (see all the other .c files in contrib/libtests) because it
+    depends on PNG_LIBPNG_VER.
+  Moved pngcp to contrib/tools and added pngcp to the build together
+    with a pngcp.dfa configuration test (John Bowler)
+  Added a "Common linking failures" section to the INSTALL document.
+  Relocated misplaced #endif in png.c sRGB profile checking.
+  Fixed two Coverity issues in pngcp.c.
+
+Version 1.7.0beta83 [July 23, 2016]
+  Fixed some indentation to comply with our coding style.
+  Removed/rearranged certain png_struct fields that are only used
+    in reading.
+  Fixed debug test of output gamma.
+
+Version 1.7.0beta84 [September 26, 2016]
+  Minor editing of INSTALL, (whitespace, added copyright line)
+  Don't install pngcp; it conflicts with pngcp in the pngtools package.
+  Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
+    bugfix by John Bowler).
+  Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c
+  Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngrutil.c.
+  If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
+    ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
+  Issue png_benign_error() on ADLER32 checksum mismatch instead of png_error().
+  Add tests/badcrc.png and tests/badadler.png to tests/pngtest.
+
+Version 1.7.0beta85 [December 27, 2016]
+  Updated the documentation about CRC and ADLER32 handling.
+  Quieted warnings from clang-3.8 in pngunknown.c and pngvalid.c.
+  Removed the use of a macro containing the pre-processor 'defined'
+    operator.  It is unclear whether this is valid; a macro that
+    "generates" 'defined' is not permitted, but the use of the word
+    "generates" within the C90 standard seems to imply more than simple
+    substitution of an expression itself containing a well-formed defined
+    operation.
+
+Version 1.7.0beta86 [December 29, 2016]
+  Ported CMakeLists.txt from libpng-1.6.27rc01.
+  Fixed a potential null pointer dereference in png_set_text_2() (bug report
+    and patch by Patrick Keshishian, CVE-2016-10087).
+
+Version 1.7.0beta87 [April 1, 2017]
+  Fixed arm/aarch64 detection in CMakeLists.txt (Gianfranco Costamagna).
+  The contrib/examples/pngtopng.c recovery code was in the wrong "if"
+    branches; the comments were correct.
+  Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in
+    makefile.linux and makefile.solaris-x86 (Cosmin).
+  Merged some recent changes from libpng-1.6.30beta01.
+
+Version 1.7.0beta88 [August 7. 2017]
+  Added private png_check_chunk_name() and png_check_chunk_length()
+    functions (Fixes CVE-2017-12652).
+
+Version 1.7.0beta89 [August 19, 2017]
+  Check for 0 return from png_get_rowbytes() in contrib/pngminus/*.c to stop
+    some Coverity issues (162705, 162706, and 162707).
+
+Version 1.7.0beta90 [September 3, 2017]
+  Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing
+    parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).
+  Compute a larger limit on IDAT because some applications write a deflate
+    buffer for each row (Bug report by Andrew Church).
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CHANGES

@@ -5590,6 +5590,162 @@ Version 1.7.0beta80 [May 6, 2016]
       unreachable code in pz_default_settings and eliminated a spurious
       warning in pngcp for small files.
 
+Version 1.7.0beta81 [June 11, 2016]
+  Check for CLOCK_PROCESS_CPUTIME_ID when building /contrib/libtests/timepng.
+    Otherwise it does not build on platforms that don't supply clock_gettime().
+  Add check for clock_gettime() in Makefile.am and configure.ac
+  Reenabled filter selection (dummy).  This implements the code for
+    row-by-row filter selection but does not provide an actual implementation;
+    the selection function just chooses the lowest set filter bit.
+  Fixed a signed/unsigned warning (GCC 4.8.5) in pngwutil.c
+  Implemented base filter selection with row buffering and a crude code-count
+    algorithm.
+  Added filter selection, palette index checks.  Palette index checking:
+    checking on read was erroneously skipped.  pngcp can now turn off the
+    palette index checking or fix the errors (mainly to allow comparison with
+    libpng 1.6, which defaulted to ignoring it).  The API now documents how
+    the 'enabled' parameter works.  On read the check is on by default (it
+    was apparently off in libpng 1.6) however now if explicitly turned on the
+    warning message is stopped; this provides better interaction with
+    get_palette_max at the cost of a small API change (may need to be reviewed.)
+  Palette size errors: invalid entries in the palette are now set to #beaded to
+    make the errors more obvious and allow easy detection in memory.
+  Read transform pipeline caching: changes to fix the palette index check
+    (which are erroneously cached), the pipeline can now contain multiple
+    caches, e.g., caching of packing of palette indices can be combined with
+    caching of palette RGB transforms.
+  Read code now checks for callbacks to read 0 data (and faults them).
+    Fixed the reading of PNGs with multiple 0 length IDATs that failed as a
+    result plus the handling of zero length unknown (which occurs, validly;
+    the spurious warning has been removed).
+  Filter selection: the 1.6 and earlier sum of absolute differences algorithm
+    has been reintroduced with an option to disfavor some filters over others
+    where the sums are close (not yet exposed).  The selection code also logs
+    the last known occurence of each possible byte code across multiple lines.
+    This allows detection of PNG images with lower bit depth than the format
+    implies and, therefore, allows the filtering to be turned off in those
+    cases as well.
+  The default write zlib settings are still lower than libpng16.  The
+    selection algorithm is being refined (the overall results are worse than
+    not doing any filtering).
+  Port contrib/libtests/pngvalid.c from libpng16.
+  PNG compression level setting API: this allows the various compression
+    settings controlling deflate, fitlering, and so on to be set via a single
+    setting with six values.  This is currently documented in png.h ("Write
+    compression settings").
+  Internally the compression settings have been tuned both for the overall
+    setting and for any specific settings made by the original APIs.
+  APIs to control iCCP chunk compression separately have been added.
+  contrib/examples/pngcp.c has been modified to accomodate the new compression
+    setting and to include options for separate control of iCCP chunk
+    compression.
+  The new "png_setting" ABI has been modified to accomodate a wider range of
+    settings and most of the old compression control ABIs have been replaced by
+    function-like macros with the same API which call png_setting.  This is an
+    API check in 1.7.0 for png_setting (alone).  png_setting now handles all
+    of png_set_option.  This eliminates 19 ABIs at the cost of adding 1
+    (png_setting).
+  CRC and benign error checking has been updated internally to use bit-fields
+    and the CRC calculation skip when the CRC is not used has been improved
+    slightly to avoid the initialization of the CRC.  A new png_setting based
+    API allows more detailed control of benign error/warning messages (this
+    may change, the internal error handling seems too complex.)  The
+    ERROR_NUMBERS support has been removed with the intent of implementing
+    proper i18n.
+  The memcpy-size-0 issue in png_push_fill_buffer has been fixed, with an
+    appropriate debug() assert if a fill for 0 bytes occurs.
+  Most PNG_FLAG_ values for png_struct::flags have been eliminated (as a
+    result of the benign error handling changes).  Only one remains.
+  The LOW_MEMORY PNG_COMPRESSION option should not be setting HUFFMAN_ONLY or
+    using a low deflate 'level'; according to the comments in zconf.h only
+    windowBits and memLevel affect the memory.  pngwutil.c has been changed
+    to use the same values as HIGH compression.
+  The COMPAT option turned on the old optimize_cmf code (now in fix_cinfo),
+    however there was a serious bug in that code; it put the wrong value in
+    z_cmf.  The setting was also not handled correctly in
+    pz_compression_settings.
+  pngtest now verifies the operation of COMPAT and, as a result, pngtest.png
+    has been reverted to the libpng 1.6 (etc) version.
+  IDAT size handling has been improved; if not explicitly set values
+    appropriate to png_level are now chosen (in addition to the handling for
+    the COMPAT setting).  HIGH and HIGH_READ_SPEED now create unlimited
+    (up to the PNG chunk-size limit of 2^31-1 bytes) size IDAT chunks,
+    which requires buffering the whole of the IDAT data in memory but
+    reflects what other programs and optimizers do.
+  Changed handling of PNG_IMAGE_FLAG_FAST in the simplified API to use
+    PNG_COMPRESSION_HIGH_SPEED, and PNG_COMPRESSION_HIGH otherwise.
+  Removed png_struct::flags which is no longer used.
+  Fixed implementations of png_app_error() and png_app_warning() which
+    previously were swapped.
+  Avoid potential overflow of the PNG_IMAGE_SIZE macro.  This macro
+    is not used within libpng, but is used in some of the examples.
+
+Version 1.7.0beta82 [July 4, 2016]
+  Put the SKIP definition in the correct place. It needs to come after the
+    png.h include (see all the other .c files in contrib/libtests) because it
+    depends on PNG_LIBPNG_VER.
+  Moved pngcp to contrib/tools and added pngcp to the build together
+    with a pngcp.dfa configuration test (John Bowler)
+  Added a "Common linking failures" section to the INSTALL document.
+  Relocated misplaced #endif in png.c sRGB profile checking.
+  Fixed two Coverity issues in pngcp.c.
+
+Version 1.7.0beta83 [July 23, 2016]
+  Fixed some indentation to comply with our coding style.
+  Removed/rearranged certain png_struct fields that are only used
+    in reading.
+  Fixed debug test of output gamma.
+
+Version 1.7.0beta84 [September 26, 2016]
+  Minor editing of INSTALL, (whitespace, added copyright line)
+  Don't install pngcp; it conflicts with pngcp in the pngtools package.
+  Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
+    bugfix by John Bowler).
+  Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c
+  Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngrutil.c.
+  If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
+    ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
+  Issue png_benign_error() on ADLER32 checksum mismatch instead of png_error().
+  Add tests/badcrc.png and tests/badadler.png to tests/pngtest.
+
+Version 1.7.0beta85 [December 27, 2016]
+  Updated the documentation about CRC and ADLER32 handling.
+  Quieted warnings from clang-3.8 in pngunknown.c and pngvalid.c.
+  Removed the use of a macro containing the pre-processor 'defined'
+    operator.  It is unclear whether this is valid; a macro that
+    "generates" 'defined' is not permitted, but the use of the word
+    "generates" within the C90 standard seems to imply more than simple
+    substitution of an expression itself containing a well-formed defined
+    operation.
+
+Version 1.7.0beta86 [December 29, 2016]
+  Ported CMakeLists.txt from libpng-1.6.27rc01.
+  Fixed a potential null pointer dereference in png_set_text_2() (bug report
+    and patch by Patrick Keshishian, CVE-2016-10087).
+
+Version 1.7.0beta87 [April 1, 2017]
+  Fixed arm/aarch64 detection in CMakeLists.txt (Gianfranco Costamagna).
+  The contrib/examples/pngtopng.c recovery code was in the wrong "if"
+    branches; the comments were correct.
+  Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in
+    makefile.linux and makefile.solaris-x86 (Cosmin).
+  Merged some recent changes from libpng-1.6.30beta01.
+
+Version 1.7.0beta88 [August 7, 2017]
+  Initialized btoa[] in pngstest.c
+  Added private png_check_chunk_name() and png_check_chunk_length()
+    functions (Fixes CVE-2017-12652).
+
+Version 1.7.0beta89 [August 19, 2017]
+  Check for 0 return from png_get_rowbytes() in contrib/pngminus/*.c to stop
+    some Coverity issues (162705, 162706, and 162707).
+
+Version 1.7.0beta90 [September 3, 2017]
+  Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing
+    parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).
+  Compute a larger limit on IDAT because some applications write a deflate
+    buffer for each row (Bug report by Andrew Church).
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CMakeLists.txt

@@ -5,6 +5,7 @@
 # Revised by Roger Lowman, 2009-2010
 # Revised by Clifford Yapp, 2011-2012
 # Revised by Roger Leigh, 2016
+# Revised by Andreas Franek, 2016
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -69,6 +70,36 @@ option(PNGARG        "Disable ANSI-C prototypes" OFF)
 set(PNG_PREFIX "" CACHE STRING "Prefix to add to the API function names")
 set(DFA_XTRA "" CACHE FILEPATH "File containing extra configuration settings")
 
+# set definitions and sources for arm
+if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "^arm" OR
+  ${CMAKE_SYSTEM_PROCESSOR} MATCHES "^aarch64")
+  set(PNG_ARM_NEON_POSSIBLE_VALUES check on off)
+  set(PNG_ARM_NEON "check" CACHE STRING "Enable ARM NEON optimizations:
+     check: (default) use internal checking code;
+     off: disable the optimizations;
+     on: turn on unconditionally.")
+  set_property(CACHE PNG_ARM_NEON PROPERTY STRINGS
+     ${PNG_ARM_NEON_POSSIBLE_VALUES})
+  list(FIND PNG_ARM_NEON_POSSIBLE_VALUES ${PNG_ARM_NEON} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+      " PNG_ARM_NEON must be one of [${PNG_ARM_NEON_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_ARM_NEON} STREQUAL "no")
+    set(libpng_arm_sources
+      arm/arm_init.c
+      arm/filter_neon.S
+      arm/filter_neon_intrinsics.c)
+      
+    if(${PNG_ARM_NEON} STREQUAL "on")
+      add_definitions(-DPNG_ARM_NEON_OPT=2)
+    elseif(${PNG_ARM_NEON} STREQUAL "check")
+      add_definitions(-DPNG_ARM_NEON_CHECK_SUPPORTED)
+    endif()
+  else()
+    add_definitions(-DPNG_ARM_NEON_OPT=0)
+  endif()
+endif()
+
 # SET LIBNAME
 set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR})
 
@@ -360,6 +391,7 @@ set(libpng_sources
   pngwrite.c
   pngwtran.c
   pngwutil.c
+  ${libpng_arm_sources}
 )
 set(pngtest_sources
   pngtest.c
@@ -697,7 +729,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(png PROPERTIES
-#   VERSION 17.${PNGLIB_RELEASE}.1.7.0beta80
+#   VERSION 17.${PNGLIB_RELEASE}.1.7.0beta90
     VERSION 17.${PNGLIB_RELEASE}.0
     SOVERSION 17
     CLEAN_DIRECT_OUTPUT 1)

INSTALL

@@ -1,24 +1,25 @@
 
-Installing libpng
+    Installing libpng
 
 Contents
 
-   I. Simple installation
-  II. Rebuilding the configure scripts
- III. Using scripts/makefile*
-  IV. Using cmake
-   V. Directory structure
-  VI. Building with project files
- VII. Building with makefiles
-VIII. Configuring libpng for 16-bit platforms
-  IX. Configuring for DOS
-   X. Configuring for Medium Model
-  XI. Prepending a prefix to exported symbols
- XII. Configuring for compiler xxx:
-XIII. Removing unwanted object code
- XIV. Changes to the build and configuration of libpng in libpng-1.5.x
-  XV. Setjmp/longjmp issues
- XVI. Other sources of information about libpng
+       I. Simple installation
+      II. Rebuilding the configure scripts
+     III. Using scripts/makefile*
+      IV. Using cmake
+       V. Directory structure
+      VI. Building with project files
+     VII. Building with makefiles
+    VIII. Configuring libpng for 16-bit platforms
+      IX. Configuring for DOS
+       X. Configuring for Medium Model
+      XI. Prepending a prefix to exported symbols
+     XII. Configuring for compiler xxx:
+    XIII. Removing unwanted object code
+     XIV. Changes to the build and configuration of libpng in libpng-1.5.x
+      XV. Setjmp/longjmp issues
+     XVI. Common linking failures
+    XVII. Other sources of information about libpng
 
 I. Simple installation
 
@@ -47,7 +48,9 @@ If configure does not work on your system, or if you have a need to
 change configure.ac or Makefile.am, and you have a reasonably
 up-to-date set of tools, running ./autogen.sh in a git clone before
 running ./configure may fix the problem.  To be really sure that you
-aren't using any of the included pre-built scripts, you can do this:
+aren't using any of the included pre-built scripts, especially if you
+are building from a tar distribution instead of a git distribution,
+do this:
 
     ./configure --enable-maintainer-mode
     make maintainer-clean
@@ -76,7 +79,7 @@ Or you can use one of the "projects" in the "projects" directory.
 Before installing libpng, you must first install zlib, if it
 is not already on your system.  zlib can usually be found
 wherever you got libpng; otherwise go to http://zlib.net.  You can place
-zlib in in the same directory as libpng or in another directory.
+zlib in the same directory as libpng or in another directory.
 
 If your system already has a preinstalled zlib you will still need
 to have access to the zlib.h and zconf.h include files that
@@ -87,22 +90,24 @@ standard library search path, put ZLIBLIB, ZLIBINC, CPPFLAGS, LDFLAGS,
 and LD_LIBRARY_PATH in your environment before running "make test"
 or "make distcheck":
 
-ZLIBLIB=/path/to/lib export ZLIBLIB
-ZLIBINC=/path/to/include export ZLIBINC
-CPPFLAGS="-I$ZLIBINC" export CPPFLAGS
-LDFLAGS="-L$ZLIBLIB" export LDFLAGS
-LD_LIBRARY_PATH="$ZLIBLIB:$LD_LIBRARY_PATH" export LD_LIBRARY_PATH
+    ZLIBLIB=/path/to/lib export ZLIBLIB
+    ZLIBINC=/path/to/include export ZLIBINC
+    CPPFLAGS="-I$ZLIBINC" export CPPFLAGS
+    LDFLAGS="-L$ZLIBLIB" export LDFLAGS
+    LD_LIBRARY_PATH="$ZLIBLIB:$LD_LIBRARY_PATH" export LD_LIBRARY_PATH
 
 If you are using one of the makefile scripts, put ZLIBLIB and ZLIBINC
-in your environment and type "make ZLIBLIB=$ZLIBLIB ZLIBINC=$ZLIBINC test".
+in your environment and type
+
+    make ZLIBLIB=$ZLIBLIB ZLIBINC=$ZLIBINC test
 
 IV. Using cmake
 
 If you want to use "cmake" (see www.cmake.org), type
 
-   cmake . -DCMAKE_INSTALL_PREFIX=/path
-   make
-   make install
+    cmake . -DCMAKE_INSTALL_PREFIX=/path
+    make
+    make install
 
 As when using the simple configure method described above, "/path" points to
 the installation directory where you want to put the libpng "lib", "include",
@@ -116,8 +121,8 @@ or "zlib128") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
 
-   ..       (the parent directory)
-      libpng  (this directory)
+    .. (the parent directory)
+      libpng (this directory)
           INSTALL (this file)
           README
           *.h, *.c  => libpng source files
@@ -160,10 +165,15 @@ VII. Building with makefiles
 Copy the file (or files) that you need from the
 scripts directory into this directory, for example
 
-   MSDOS example: copy scripts\makefile.msc makefile
-                  copy scripts\pnglibconf.h.prebuilt pnglibconf.h
-   UNIX example:  cp scripts/makefile.std makefile
-                  cp scripts/pnglibconf.h.prebuilt pnglibconf.h
+MSDOS example:
+
+    copy scripts\makefile.msc makefile
+    copy scripts\pnglibconf.h.prebuilt pnglibconf.h
+
+UNIX example:
+
+    cp scripts/makefile.std makefile
+    cp scripts/pnglibconf.h.prebuilt pnglibconf.h
 
 Read the makefile to see if you need to change any source or
 target directories to match your preferences.
@@ -230,7 +240,8 @@ The files in libpng proper only include pngpriv.h and png.h, which
 in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h.
 As of libpng-1.5.0, pngpriv.h also includes three other private header
 files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
-that previously appeared in the public headers.
+that previously appeared in the public headers. As of libpng-1.7.0,
+pngchunk.h is also included, and is used privately by pngrutil.c.
 
 XIII. Removing unwanted object code
 
@@ -239,7 +250,7 @@ libpng are compiled.  All the defines end in _SUPPORTED.  If you are
 never going to use a capability, you can change the #define to #undef
 before recompiling libpng and save yourself code and data space, or
 you can turn off individual capabilities with defines that begin with
-PNG_NO_.
+"PNG_NO_".
 
 In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead.
 
@@ -307,7 +318,7 @@ only png_longjmp_ptr, which must match the C longjmp function.)  The new
 approach is documented in pngconf.h
 
 Despite these changes, libpng 1.5.0 only supports the native C function
-calling standard on those platforms tested so far (__cdecl on Microsoft
+calling standard on those platforms tested so far ("__cdecl" on Microsoft
 Windows).  This is because the support requirements for alternative
 calling conventions seem to no longer exist.  Developers who find it
 necessary to set PNG_API_RULE to 1 should advise the mailing list
@@ -371,7 +382,7 @@ your application is going to be using multiple threads, you should
 configure libpng with PNG_NO_SETJMP in your pngusr.dfa file, with
 -DPNG_NO_SETJMP on your compile line, or with
 
-  #undef PNG_SETJMP_SUPPORTED
+    #undef PNG_SETJMP_SUPPORTED
 
 in your pnglibconf.h or pngusr.h.
 
@@ -380,28 +391,25 @@ This requires setjmp/longjmp, so you must either build the library
 with PNG_SETJMP_SUPPORTED defined, or with PNG_SIMPLIFIED_READ_SUPPORTED
 and PNG_SIMPLIFIED_WRITE_SUPPORTED undefined.
 
-XVI. Other sources of information about libpng:
+XVI. Common linking failures
+
+If your application fails to find libpng or zlib entries while linking:
+
+  Be sure "-lz" appears after "-lpng" on your linking command.
+
+  Be sure you have built libpng, zlib, and your application for the
+  same platform (e.g., 32-bit or 64-bit).
+
+  If you are using the vstudio project, observe the WARNING in
+  project/vstudio/README.txt.
+
+XVII. Other sources of information about libpng:
 
 Further information can be found in the README and libpng-manual.txt
 files, in the individual makefiles, in png.h, and the manual pages
 libpng.3 and png.5.
 
-Using the ./configure script -- 16 December 2002.
-=================================================
-
-The ./configure script should work compatibly with what scripts/makefile.*
-did, however there are some options you might need to add to configure
-explicitly, which previously was done semi-automatically (if you didn't edit
-scripts/makefile.* yourself, that is)
-
-CFLAGS="-Wall -O -funroll-loops \
--malign-loops=2 -malign-functions=2" ./configure --prefix=/usr/include \
---with-pkgconfigdir=/usr/lib/pkgconfig --includedir=/usr/include
-
-You can alternatively specify --includedir=/usr/include, /usr/local/include,
-/usr/include/libpng17, or whatever.
-
-If you find that the configure script is out-of-date or is not supporting
-your platform properly, try running autogen.sh to regenerate "configure",
-"Makefile.in", and the other configuration files. Then try configure again.
-
+Copyright (c) 1998-2002,2006-2016 Glenn Randers-Pehrson
+This document is released under the libpng license.
+For conditions of distribution and use, see the disclaimer
+and license in png.h.

LICENSE

@@ -10,8 +10,8 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000, through 1.7.0beta80, May 6, 2016, are
-Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
+libpng versions 1.0.7, July 1, 2000 through 1.7.0beta90, August 28, 2017 are
+Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
 added to the list of Contributing Authors:
@@ -32,6 +32,10 @@ and with the following additions to the disclaimer:
    risk of satisfactory quality, performance, accuracy, and effort is with
    the user.
 
+Some files in the "contrib" directory and some configure-generated
+files that are distributed with libpng have other copyright owners and
+are released under other open source licenses.
+
 libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
 Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
 libpng-0.96, and are distributed according to the same disclaimer and
@@ -55,6 +59,9 @@ Contributing Authors:
    Greg Roelofs
    Tom Tanner
 
+Some files in the "scripts" directory have other copyright owners
+but are released under this license.
+
 libpng versions 0.5, May 1995, through 0.88, January 1996, are
 Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 
@@ -95,18 +102,29 @@ appreciated.
 
 END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
 
-A "png_get_copyright" function is available, for convenient use in "about"
-boxes and the like:
+TRADEMARK:
 
-   printf("%s", png_get_copyright(NULL));
+The name "libpng" has not been registered by the Copyright owner
+as a trademark in any jurisdiction.  However, because libpng has
+been distributed and maintained world-wide, continually since 1995,
+the Copyright owner claims "common-law trademark protection" in any
+jurisdiction where common-law trademark is recognized.
 
-Also, the PNG logo (in PNG format, of course) is supplied in the
-files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+OSI CERTIFICATION:
 
 Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
 a certification mark of the Open Source Initiative. OSI has not addressed
 the additional disclaimers inserted at version 1.0.7.
 
+EXPORT CONTROL:
+
+The Copyright owner believes that the Export Control Classification
+Number (ECCN) for libpng is EAR99, which means not subject to export
+controls or International Traffic in Arms Regulations (ITAR) because
+it is open source, publicly available software, that does not contain
+any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
+734.7(b).
+
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-May 6, 2016
+August 28, 2017

Makefile.am

@@ -1,13 +1,21 @@
-# Makefile.am:
-#   Source file for Makefile.in (and hence Makefile)
+# Makefile.am, the source file for Makefile.in (and hence Makefile), is
 #
+# Copyright (c) 2004-2016 Glenn Randers-Pehrson
+# Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
 
 PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
 
 ACLOCAL_AMFLAGS = -I scripts
 
 # test programs - run on make check, make distcheck
-check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage
+check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage pngcp 
+if HAVE_CLOCK_GETTIME
+check_PROGRAMS += timepng
+endif
 
 # Utilities - installed
 bin_PROGRAMS= pngfix png-fix-itxt
@@ -42,6 +50,12 @@ pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 
 png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
 
+timepng_SOURCES = contrib/libtests/timepng.c
+timepng_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngcp_SOURCES = contrib/tools/pngcp.c
+pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
 # Generally these are single line shell scripts to run a test with a particular
 # set of parameters:
 TESTS =\
@@ -225,6 +239,7 @@ contrib/libtests/timepng.o: pnglibconf.h
 
 contrib/tools/makesRGB.o: pnglibconf.h
 contrib/tools/pngfix.o: pnglibconf.h
+contrib/tools/pngcp.o: pnglibconf.h
 
 # We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually
 # be built with PNG_USE_READ_MACROS; this prevents the read macros from
@@ -271,7 +286,8 @@ scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.ou
 scripts/pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
 	rm -f $@ pnglibconf.tf[67]
 	test -z "$(CPPFLAGS)" -a -z "$(AM_CPPFLAGS)"
-	echo "com libpng @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
+	(echo "com libpng @PNGLIB_VERSION@ STANDARD API DEFINITION";\
+	 echo "com") |\
 	$(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf6\
 	    logunsupported=1 version=search ${srcdir}/pngconf.h -\
 	    ${srcdir}/scripts/pnglibconf.dfa 1>&2

README

@@ -1,4 +1,4 @@
-README for libpng version 1.7.0beta80 - May 6, 2016 (shared library 17.0)
+README for libpng version 1.7.0beta90 - August 28, 2017 (shared library 17.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
@@ -23,7 +23,7 @@ earlier versions if you are using a shared library.  The type of the
 png_uint_32, which will affect shared-library applications that use
 this function.
 
-To avoid problems with changes to the internals of png info_struct,
+To avoid problems with changes to the internals of the png info_struct,
 new APIs have been made available in 0.95 to avoid direct application
 access to info_ptr.  These functions are the png_set_<chunk> and
 png_get_<chunk> functions.  These functions should be used when
@@ -88,11 +88,11 @@ zlib should be available at the same place that libpng is, or at zlib.net.
 
 You may also want a copy of the PNG specification.  It is available
 as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
-these at http://www.libpng.org/pub/png/documents/
+these at http://www.libpng.org/pub/png/pngdocs.html .
 
-This code is currently being archived at libpng.sf.net in the
-[DOWNLOAD] area, and at ftp://ftp.simplesystems.org.  If you can't find it
-in any of those places, e-mail me, and I'll help you find it.
+This code is currently being archived at libpng.sourceforge.io in the
+[DOWNLOAD] area, and at ftp://ftp-osl.osuosl.org/pub/libpng/src .  If you
+can't find it in any of those places, e-mail me, and I'll help you find it.
 
 I am not a lawyer, but I believe that the Export Control Classification
 Number (ECCN) for libpng is EAR99, which means not subject to export

TODO

@@ -5,13 +5,14 @@ Final bug fixes.
 Better C++ wrapper/full C++ implementation?
 Fix problem with C++ and EXTERN "C".
 cHRM transformation.
-Remove setjmp/longjmp usage in favor of returning error codes.
+Remove setjmp/longjmp usage in favor of returning error codes. As a start on
+  this, minimize the use of png_error(), replacing them with
+  png_warning(); return(0); or similar.
 Palette creation.
 Add "grayscale->palette" transformation and "palette->grayscale" detection.
 Improved dithering.
 Multi-lingual error and warning message support.
 Complete sRGB transformation (presently it simply uses gamma=0.45455).
-Make profile checking optional via a png_set_something() call.
 Man pages for function calls.
 Better documentation.
 Better filter selection
@@ -23,8 +24,8 @@ Use greater precision when changing to linear gamma for compositing against
   background and doing rgb-to-gray transformation.
 Investigate pre-incremented loop counters and other loop constructions.
 Add interpolated method of handling interlacing.
-Switch to the simpler zlib (zlib/libpng) license if legally possible.
 Extend pngvalid.c to validate more of the libpng transformations.
 Refactor preprocessor conditionals to compile entire statements
+Quiet compiler warnings (mostly -Wconversion warnings).
 
 */

configure.ac

@@ -1,5 +1,13 @@
 # configure.ac
 
+# Copyright (c) 2004-2016 Glenn Randers-Pehrson
+# Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+
 dnl Process this file with autoconf to produce a configure script.
 dnl
 dnl Minor upgrades (compatible ABI): increment the package version
@@ -18,7 +26,7 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.7.0beta80],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.7.0beta90],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -30,7 +38,7 @@ AC_CONFIG_MACRO_DIR([scripts])
 # 1.14.1 is required for %reldir% support
 AM_INIT_AUTOMAKE([1.15 foreign dist-xz color-tests silent-rules subdir-objects])
 # The following line causes --disable-maintainer-mode to be the default to
-# configure, this is necessary because libpng distributions cannot rely on the
+# configure. This is necessary because libpng distributions cannot rely on the
 # time stamps of the autotools generated files being correct
 AM_MAINTAINER_MODE
 
@@ -40,7 +48,7 @@ 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=1.7.0beta80
+PNGLIB_VERSION=1.7.0beta90
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=7
 PNGLIB_RELEASE=0
@@ -136,6 +144,11 @@ AC_C_RESTRICT
 AC_CHECK_FUNCS([memset memcpy strncpy],,
                AC_MSG_FAILURE([missing ANSI-C functions]))
 
+# Some later POSIX 1003.1 functions are required for test programs, failure here
+# is soft (the corresponding test program is not built).
+AC_CHECK_FUNC([clock_gettime],,[AC_MSG_WARN([not building timepng])])
+AM_CONDITIONAL([HAVE_CLOCK_GETTIME], [test "$ac_cv_func_clock_gettime" = "yes"])
+
 # floor and ceil are required for FLOATING_POINT, but they can be turned off on
 # the configure command line (and they are independent.)  Default is to 'on'
 AC_ARG_ENABLE([floating-point],
@@ -173,7 +186,7 @@ then
                    enable_floating_arithmetic=no])
 fi
 
-# Set the relevant defines if required (only if required), this will override
+# Set the relevant defines if required (only if required). This will override
 # anything on the command line.
 if test "$enable_floating_point" != yes
 then

contrib/arm-neon/android-ndk.c

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

contrib/conftest/pngcp.dfa

@@ -0,0 +1,38 @@
+# pngcp.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2016
+# 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 support for pngcp.  This means just png_read_png,
+# png_write_png and small number of configuration settings.
+#
+everything = off
+
+# Options to turn on png_read_png and png_write_png:
+option WRITE_PNG on
+option READ_PNG on
+option EASY_ACCESS on
+option WRITE_16BIT on
+option SELECT_FILTER on
+
+# pngcp needs this to preserve unknown chunks, switching all these on means that
+# pngcp can work without explicit known chunk reading suppport
+option SAVE_UNKNOWN_CHUNKS on
+option WRITE_UNKNOWN_CHUNKS on
+
+# pngcp needs this to handle palette files with invalid indices:
+option CHECK_FOR_INVALID_INDEX on
+option GET_PALETTE_MAX on
+
+# this is used to turn off limits:
+option USER_LIMITS on
+option SET_USER_LIMITS on
+
+# these are are just required for specific customizations
+option WRITE_CUSTOMIZE_ZTXT_COMPRESSION on
+option WRITE_CUSTOMIZE_COMPRESSION on

contrib/examples/pngtopng.c

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

contrib/gregbook/README

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

contrib/libtests/pngimage.c

@@ -2,7 +2,7 @@
  *
  * Copyright (c) 2015,2016 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.22 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.22 [May 26, 2016]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -45,8 +45,19 @@
 #  define SKIP 0
 #endif
 
-#if defined(PNG_INFO_IMAGE_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_SUPPORTED)\
-    && (defined(PNG_READ_PNG_SUPPORTED) || PNG_LIBPNG_VER < 10700)
+#if PNG_LIBPNG_VER < 10700
+   /* READ_PNG and WRITE_PNG were not defined, so: */
+#  ifdef PNG_INFO_IMAGE_SUPPORTED
+#     ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#        define PNG_READ_PNG_SUPPORTED
+#     endif /* SEQUENTIAL_READ */
+#     ifdef PNG_WRITE_SUPPORTED
+#        define PNG_WRITE_PNG_SUPPORTED
+#     endif /* WRITE */
+#  endif /* INFO_IMAGE */
+#endif /* pre 1.7.0 */
+
+#ifdef PNG_READ_PNG_SUPPORTED
 /* If a transform is valid on both read and write this implies that if the
  * transform is applied to read it must also be applied on write to produce
  * meaningful data.  This is because these transforms when performed on read
@@ -395,7 +406,7 @@ buffer_destroy(struct buffer *buffer)
    buffer_destroy_list(list);
 }
 
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
 static void
 buffer_start_write(struct buffer *buffer)
 {
@@ -565,7 +576,7 @@ struct display
    png_structp    read_pp;
    png_infop      read_ip;
 
-#  ifdef PNG_WRITE_SUPPORTED
+#  ifdef PNG_WRITE_PNG_SUPPORTED
       /* Used to write a new image (the original info_ptr is used) */
       png_structp   write_pp;
       struct buffer written_file;   /* where the file gets written */
@@ -592,7 +603,7 @@ display_init(struct display *dp)
    dp->read_ip = NULL;
    buffer_init(&dp->original_file);
 
-#  ifdef PNG_WRITE_SUPPORTED
+#  ifdef PNG_WRITE_PNG_SUPPORTED
       dp->write_pp = NULL;
       buffer_init(&dp->written_file);
 #  endif
@@ -605,7 +616,7 @@ display_clean_read(struct display *dp)
       png_destroy_read_struct(&dp->read_pp, &dp->read_ip, NULL);
 }
 
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
 static void
 display_clean_write(struct display *dp)
 {
@@ -617,7 +628,7 @@ display_clean_write(struct display *dp)
 static void
 display_clean(struct display *dp)
 {
-#  ifdef PNG_WRITE_SUPPORTED
+#  ifdef PNG_WRITE_PNG_SUPPORTED
       display_clean_write(dp);
 #  endif
    display_clean_read(dp);
@@ -635,7 +646,7 @@ static void
 display_destroy(struct display *dp)
 {
     /* Release any memory held in the display. */
-#  ifdef PNG_WRITE_SUPPORTED
+#  ifdef PNG_WRITE_PNG_SUPPORTED
       buffer_destroy(&dp->written_file);
 #  endif
 
@@ -1082,6 +1093,7 @@ compare_read(struct display *dp, int applied_transforms)
       }
 
       else
+#     ifdef PNG_sBIT_SUPPORTED
       {
          unsigned long y;
          int bpp;   /* bits-per-pixel then bytes-per-pixel */
@@ -1243,12 +1255,16 @@ compare_read(struct display *dp, int applied_transforms)
             }
          } /* for y */
       }
+#     else /* !sBIT */
+         display_log(dp, INTERNAL_ERROR,
+               "active shift transform but no sBIT support");
+#     endif /* !sBIT */
    }
 
    return 1; /* compare succeeded */
 }
 
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
 static void
 buffer_write(struct display *dp, struct buffer *buffer, png_bytep data,
    png_size_t size)
@@ -1347,7 +1363,7 @@ write_png(struct display *dp, png_infop ip, int transforms)
     */
    display_clean_write(dp);
 }
-#endif /* WRITE_SUPPORTED */
+#endif /* WRITE_PNG */
 
 static int
 skip_transform(struct display *dp, int tr)
@@ -1409,7 +1425,7 @@ test_one_file(struct display *dp, const char *filename)
          return; /* no point testing more */
    }
 
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
    /* Second test: write the original PNG data out to a new file (to test the
     * write side) then read the result back in and make sure that it hasn't
     * changed.
@@ -1450,7 +1466,7 @@ test_one_file(struct display *dp, const char *filename)
           * out and read it back in again (without the reversible transforms)
           * we should get back to the place where we started.
           */
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
          if ((current & write_transforms) == current)
          {
             /* All transforms reversible: write the PNG with the transformations
@@ -1686,7 +1702,7 @@ main(const int argc, const char * const * const argv)
       return errors != 0;
    }
 }
-#else /* !INFO_IMAGE || !SEQUENTIAL_READ || !READ_PNG*/
+#else /* !READ_PNG */
 int
 main(void)
 {

contrib/libtests/pngstest.c

@@ -1,9 +1,8 @@
 /*-
  * pngstest.c
  *
- * Copyright (c) 2013-2016 John Cunningham Bowler
- *
- * Last changed in libpng 1.6.22 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.31 [July 27, 2017]
+ * Copyright (c) 2013-2017 John Cunningham Bowler
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -26,15 +25,6 @@
 #  include <config.h>
 #endif
 
-/* 1.6.1 added support for the configure test harness, which uses 77 to indicate
- * a skipped test, in earlier versions we need to succeed on a skipped test, so:
- */
-#if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H)
-#  define SKIP 77
-#else
-#  define SKIP 0
-#endif
-
 /* Define the following to use this test against your installed libpng, rather
  * than the one being built here:
  */
@@ -44,6 +34,15 @@
 #  include "../../png.h"
 #endif
 
+/* 1.6.1 added support for the configure test harness, which uses 77 to indicate
+ * a skipped test, in earlier versions we need to succeed on a skipped test, so:
+ */
+#if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H)
+#  define SKIP 77
+#else
+#  define SKIP 0
+#endif
+
 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED /* Else nothing can be done */
 #include "../tools/sRGB.h"
 
@@ -2611,9 +2610,9 @@ compare_two_images(Image *a, Image *b, int via_linear,
    const unsigned int b_sample = PNG_IMAGE_SAMPLE_SIZE(formatb);
    int alpha_added, alpha_removed;
    int bchannels;
-   int btoa[4];
    png_uint_32 y;
    Transform tr;
+   int btoa[4]={0,0,0,0};
 
    /* This should never happen: */
    if (width != b->image.width || height != b->image.height)
@@ -2746,22 +2745,27 @@ compare_two_images(Image *a, Image *b, int via_linear,
        */
       else if ((a->opts & ACCUMULATE) == 0)
       {
+#        ifdef __GNUC__
+#           define BYTE_CHARS 20 /* 2^32: GCC sprintf warning */
+#        else
+#           define BYTE_CHARS 3 /* 2^8: real maximum value */
+#        endif
          /* Check the original image first,
           * TODO: deal with input images with bad pixel values?
           */
          if (amax >= a->image.colormap_entries)
          {
-            char pindex[9];
-            sprintf(pindex, "%d[%lu]", amax,
-               (unsigned long)a->image.colormap_entries);
+            char pindex[3+2*BYTE_CHARS];
+            sprintf(pindex, "%d[%u]", amax,
+               (png_byte)/*SAFE*/a->image.colormap_entries);
             return logerror(a, a->file_name, ": bad pixel index: ", pindex);
          }
 
          else if (bmax >= b->image.colormap_entries)
          {
-            char pindex[9];
-            sprintf(pindex, "%d[%lu]", bmax,
-               (unsigned long)b->image.colormap_entries);
+            char pindex[3+2*BYTE_CHARS];
+            sprintf(pindex, "%d[%u]", bmax,
+               (png_byte)/*SAFE*/b->image.colormap_entries);
             return logerror(b, b->file_name, ": bad pixel index: ", pindex);
          }
       }
@@ -2881,10 +2885,13 @@ compare_two_images(Image *a, Image *b, int via_linear,
                {
                   case 4:
                      if (pua[btoa[3]] != pub[3]) break;
+                     /* FALLTHROUGH */
                   case 3:
                      if (pua[btoa[2]] != pub[2]) break;
+                     /* FALLTHROUGH */
                   case 2:
                      if (pua[btoa[1]] != pub[1]) break;
+                     /* FALLTHROUGH */
                   case 1:
                      if (pua[btoa[0]] != pub[0]) break;
                      if (alpha_added != 4 && pub[alpha_added] != 65535) break;
@@ -2900,10 +2907,13 @@ compare_two_images(Image *a, Image *b, int via_linear,
                {
                   case 4:
                      if (psa[btoa[3]] != psb[3]) break;
+                     /* FALLTHROUGH */
                   case 3:
                      if (psa[btoa[2]] != psb[2]) break;
+                     /* FALLTHROUGH */
                   case 2:
                      if (psa[btoa[1]] != psb[1]) break;
+                     /* FALLTHROUGH */
                   case 1:
                      if (psa[btoa[0]] != psb[0]) break;
                      if (alpha_added != 4 && psb[alpha_added] != 255) break;

contrib/libtests/pngunknown.c

@@ -1,7 +1,7 @@
 
 /* pngunknown.c - test the read side unknown chunk handling
  *
- * Last changed in libpng 1.6.22 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.26 [October 20, 2016]
  * Copyright (c) 2015,2016 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
@@ -478,7 +478,7 @@ get_valid(display *d, png_infop info_ptr)
       png_textp text;
       png_uint_32 ntext = png_get_text(d->png_ptr, info_ptr, &text, NULL);
 
-      while (ntext-- > 0) switch (text[ntext].compression)
+      while (ntext > 0) switch (text[--ntext].compression)
       {
          case -1:
             flags |= PNG_INFO_tEXt;

contrib/libtests/pngvalid.c

@@ -1,9 +1,8 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.22 [(PENDING RELEASE)]
- * Copyright (c) 2014-2016 Glenn Randers-Pehrson
- * Written by John Cunningham Bowler
+ * Last changed in libpng 1.6.27 [December 29, 2016]
+ * Copyright (c) 2014-2016 John Cunningham Bowler
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -131,6 +130,17 @@ typedef png_byte *png_const_bytep;
 #include <string.h> /* For memcpy, memset */
 #include <math.h>   /* For floor */
 
+/* Convenience macros. */
+#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d))
+#define CHUNK_IHDR CHUNK(73,72,68,82)
+#define CHUNK_PLTE CHUNK(80,76,84,69)
+#define CHUNK_IDAT CHUNK(73,68,65,84)
+#define CHUNK_IEND CHUNK(73,69,78,68)
+#define CHUNK_cHRM CHUNK(99,72,82,77)
+#define CHUNK_gAMA CHUNK(103,65,77,65)
+#define CHUNK_sBIT CHUNK(115,66,73,84)
+#define CHUNK_sRGB CHUNK(115,82,71,66)
+
 /* Unused formal parameter errors are removed using the following macro which is
  * expected to have no bad effects on performance.
  */
@@ -297,38 +307,33 @@ randomize(void *pv, size_t size)
 
 #define R8(this) randomize(&(this), sizeof (this))
 
-static void r16(png_uint_16p p16, size_t count)
+#ifdef PNG_READ_SUPPORTED
+static png_byte
+random_byte(void)
 {
-   size_t i;
-
-   for (i=0; i<count; ++i)
-   {
-      unsigned char b2[2];
-      randomize(b2, sizeof b2);
-      *p16++ = png_get_uint_16(b2);
-   }
+   unsigned char b1[1];
+   randomize(b1, sizeof b1);
+   return b1[0];
 }
+#endif /* READ */
 
-#define R16(this) r16(&(this), (sizeof (this))/(sizeof (png_uint_16)))
-#define R16_1(this) r16(&(this), (size_t) 1U)
+static png_uint_16
+random_u16(void)
+{
+   unsigned char b2[2];
+   randomize(b2, sizeof b2);
+   return png_get_uint_16(b2);
+}
 
 #if defined PNG_READ_RGB_TO_GRAY_SUPPORTED ||\
     defined PNG_READ_FILLER_SUPPORTED
-static void r32(png_uint_32p p32, size_t count)
+static png_uint_32
+random_u32(void)
 {
-   size_t i;
-
-   for (i=0; i<count; ++i)
-   {
-      unsigned char b4[4];
-      randomize(b4, sizeof b4);
-      *p32++ = png_get_uint_32(b4);
-   }
+   unsigned char b4[4];
+   randomize(b4, sizeof b4);
+   return png_get_uint_32(b4);
 }
-
-#define R32(this) r32(&(this), (sizeof (this))/(sizeof (png_uint_32)))
-#define R32_1(this) r32(&(this), (size_t) 1U)
-
 #endif /* READ_FILLER || READ_RGB_TO_GRAY */
 
 #endif /* READ || WRITE_tRNS || WRITE_FILTER */
@@ -338,11 +343,7 @@ static void r32(png_uint_32p p32, size_t count)
 static unsigned int
 random_mod(unsigned int max)
 {
-   png_uint_16 x;
-
-   R16_1(x);
-
-   return x % max; /* 0 .. max-1 */
+   return random_u16() % max; /* 0 .. max-1 */
 }
 #endif /* READ_TRANSFORMS || WRITE_FILTER */
 
@@ -351,11 +352,7 @@ random_mod(unsigned int max)
 static int
 random_choice(void)
 {
-   unsigned char x;
-
-   R8(x);
-
-   return x & 1;
+   return random_byte() & 1;
 }
 #endif /* READ_RGB_TO_GRAY || READ_FILLER */
 
@@ -711,6 +708,8 @@ typedef struct png_store_file
 {
    struct png_store_file*  next;      /* as many as you like... */
    char                    name[FILE_NAME_SIZE];
+   unsigned int            IDAT_bits; /* Number of bits in IDAT size */
+   png_uint_32             IDAT_size; /* Total size of IDAT data */
    png_uint_32             id;        /* must be correct (see FILEID) */
    png_size_t              datacount; /* In this (the last) buffer */
    png_store_buffer        data;      /* Last buffer in file */
@@ -766,6 +765,13 @@ typedef struct png_store
    char               test[128];      /* Name of test */
    char               error[256];
 
+   /* Share fields */
+   png_uint_32        chunklen; /* Length of chunk+overhead (chunkpos >= 8) */
+   png_uint_32        chunktype;/* Type of chunk (valid if chunkpos >= 4) */
+   png_uint_32        chunkpos; /* Position in chunk */
+   png_uint_32        IDAT_size;/* Accumulated IDAT size in .new */
+   unsigned int       IDAT_bits;/* Cache of the file store value */
+
    /* Read fields */
    png_structp        pread;    /* Used to read a saved file */
    png_infop          piread;
@@ -775,6 +781,9 @@ typedef struct png_store
    png_byte*          image;    /* Buffer for reading interlaced images */
    png_size_t         cb_image; /* Size of this buffer */
    png_size_t         cb_row;   /* Row size of the image(s) */
+   uLong              IDAT_crc;
+   png_uint_32        IDAT_len; /* Used when re-chunking IDAT chunks */
+   png_uint_32        IDAT_pos; /* Used when re-chunking IDAT chunks */
    png_uint_32        image_h;  /* Number of rows in a single image */
    store_pool         read_memory_pool;
 
@@ -861,6 +870,11 @@ store_init(png_store* ps)
    ps->pwrite = NULL;
    ps->piwrite = NULL;
    ps->writepos = 0;
+   ps->chunkpos = 8;
+   ps->chunktype = 0;
+   ps->chunklen = 16;
+   ps->IDAT_size = 0;
+   ps->IDAT_bits = 0;
    ps->new.prev = NULL;
    ps->palette = NULL;
    ps->npalette = 0;
@@ -883,6 +897,11 @@ store_freenew(png_store *ps)
 {
    store_freebuffer(&ps->new);
    ps->writepos = 0;
+   ps->chunkpos = 8;
+   ps->chunktype = 0;
+   ps->chunklen = 16;
+   ps->IDAT_size = 0;
+   ps->IDAT_bits = 0;
    if (ps->palette != NULL)
    {
       free(ps->palette);
@@ -896,9 +915,6 @@ store_storenew(png_store *ps)
 {
    png_store_buffer *pb;
 
-   if (ps->writepos != STORE_BUFFER_SIZE)
-      png_error(ps->pwrite, "invalid store call");
-
    pb = voidcast(png_store_buffer*, malloc(sizeof *pb));
 
    if (pb == NULL)
@@ -929,21 +945,52 @@ store_freefile(png_store_file **ppf)
    }
 }
 
+static unsigned int
+bits_of(png_uint_32 num)
+{
+   /* Return the number of bits in 'num' */
+   unsigned int b = 0;
+
+   if (num & 0xffff0000U)  b += 16U, num >>= 16;
+   if (num & 0xff00U)      b += 8U, num >>= 8;
+   if (num & 0xf0U)        b += 4U, num >>= 4;
+   if (num & 0xcU)         b += 2U, num >>= 2;
+   if (num & 0x2U)         ++b, num >>= 1;
+   if (num)                ++b;
+
+   return b; /* 0..32 */
+}
+
 /* Main interface to file storeage, after writing a new PNG file (see the API
  * below) call store_storefile to store the result with the given name and id.
  */
 static void
 store_storefile(png_store *ps, png_uint_32 id)
 {
-   png_store_file *pf = voidcast(png_store_file*, malloc(sizeof *pf));
+   png_store_file *pf;
+
+   if (ps->chunkpos != 0U || ps->chunktype != 0U || ps->chunklen != 0U ||
+       ps->IDAT_size == 0)
+      png_error(ps->pwrite, "storefile: incomplete write");
+
+   pf = voidcast(png_store_file*, malloc(sizeof *pf));
    if (pf == NULL)
       png_error(ps->pwrite, "storefile: OOM");
    safecat(pf->name, sizeof pf->name, 0, ps->wname);
    pf->id = id;
    pf->data = ps->new;
    pf->datacount = ps->writepos;
+   pf->IDAT_size = ps->IDAT_size;
+   pf->IDAT_bits = bits_of(ps->IDAT_size);
+   /* Because the IDAT always has zlib header stuff this must be true: */
+   if (pf->IDAT_bits == 0U)
+      png_error(ps->pwrite, "storefile: 0 sized IDAT");
    ps->new.prev = NULL;
    ps->writepos = 0;
+   ps->chunkpos = 8;
+   ps->chunktype = 0;
+   ps->chunklen = 16;
+   ps->IDAT_size = 0;
    pf->palette = ps->palette;
    pf->npalette = ps->npalette;
    ps->palette = 0;
@@ -1194,7 +1241,7 @@ store_image_check(const png_store* ps, png_const_structp pp, int iImage)
 
       image += 2; /* skip image first row markers */
 
-      while (rows-- > 0)
+      for (; rows > 0; --rows)
       {
          if (image[-2] != 190 || image[-1] != 239)
             png_error(pp, "row start overwritten");
@@ -1209,32 +1256,119 @@ store_image_check(const png_store* ps, png_const_structp pp, int iImage)
 }
 #endif /* PNG_READ_SUPPORTED */
 
+static int
+valid_chunktype(png_uint_32 chunktype)
+{
+   /* Each byte in the chunk type must be in one of the ranges 65..90, 97..122
+    * (both inclusive), so:
+    */
+   unsigned int i;
+
+   for (i=0; i<4; ++i)
+   {
+      unsigned int c = chunktype & 0xffU;
+
+      if (!((c >= 65U && c <= 90U) || (c >= 97U && c <= 122U)))
+         return 0;
+
+      chunktype >>= 8;
+   }
+
+   return 1; /* It's valid */
+}
+
 static void PNGCBAPI
 store_write(png_structp ppIn, png_bytep pb, png_size_t st)
 {
    png_const_structp pp = ppIn;
    png_store *ps = voidcast(png_store*, png_get_io_ptr(pp));
+   size_t writepos = ps->writepos;
+   png_uint_32 chunkpos = ps->chunkpos;
+   png_uint_32 chunktype = ps->chunktype;
+   png_uint_32 chunklen = ps->chunklen;
 
    if (ps->pwrite != pp)
       png_error(pp, "store state damaged");
 
+   /* Technically this is legal, but in practice libpng never writes more than
+    * the maximum chunk size at once so if it happens something weird has
+    * changed inside libpng (probably).
+    */
+   if (st > 0x7fffffffU)
+      png_error(pp, "unexpected write size");
+
+   /* Now process the bytes to be written.  Do this in units of the space in the
+    * output (write) buffer or, at the start 4 bytes for the chunk type and
+    * length limited in any case by the amount of data.
+    */
    while (st > 0)
    {
-      size_t cb;
+      if (writepos >= STORE_BUFFER_SIZE)
+         store_storenew(ps), writepos = 0;
 
-      if (ps->writepos >= STORE_BUFFER_SIZE)
-         store_storenew(ps);
+      if (chunkpos < 4)
+      {
+         png_byte b = *pb++;
+         --st;
+         chunklen = (chunklen << 8) + b;
+         ps->new.buffer[writepos++] = b;
+         ++chunkpos;
+      }
 
-      cb = st;
+      else if (chunkpos < 8)
+      {
+         png_byte b = *pb++;
+         --st;
+         chunktype = (chunktype << 8) + b;
+         ps->new.buffer[writepos++] = b;
 
-      if (cb > STORE_BUFFER_SIZE - ps->writepos)
-         cb = STORE_BUFFER_SIZE - ps->writepos;
+         if (++chunkpos == 8)
+         {
+            chunklen &= 0xffffffffU;
+            if (chunklen > 0x7fffffffU)
+               png_error(pp, "chunk length too great");
 
-      memcpy(ps->new.buffer + ps->writepos, pb, cb);
-      pb += cb;
-      st -= cb;
-      ps->writepos += cb;
-   }
+            chunktype &= 0xffffffffU;
+            if (chunktype == CHUNK_IDAT)
+            {
+               if (chunklen > ~ps->IDAT_size)
+                  png_error(pp, "pngvalid internal image too large");
+
+               ps->IDAT_size += chunklen;
+            }
+
+            else if (!valid_chunktype(chunktype))
+               png_error(pp, "invalid chunk type");
+
+            chunklen += 12; /* for header and CRC */
+         }
+      }
+
+      else /* chunkpos >= 8 */
+      {
+         png_size_t cb = st;
+
+         if (cb > STORE_BUFFER_SIZE - writepos)
+            cb = STORE_BUFFER_SIZE - writepos;
+
+         if (cb  > chunklen - chunkpos/* bytes left in chunk*/)
+            cb = (png_size_t)/*SAFE*/(chunklen - chunkpos);
+
+         memcpy(ps->new.buffer + writepos, pb, cb);
+         chunkpos += (png_uint_32)/*SAFE*/cb;
+         pb += cb;
+         writepos += cb;
+         st -= cb;
+
+         if (chunkpos >= chunklen) /* must be equal */
+            chunkpos = chunktype = chunklen = 0;
+      }
+   } /* while (st > 0) */
+
+   ps->writepos = writepos;
+   ps->chunkpos = chunkpos;
+   ps->chunktype = chunktype;
+   ps->chunklen = chunklen;
 }
 
 static void PNGCBAPI
@@ -1254,7 +1388,6 @@ store_read_buffer_size(png_store *ps)
    return ps->current->datacount;
 }
 
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 /* Return total bytes available for read. */
 static size_t
 store_read_buffer_avail(png_store *ps)
@@ -1279,7 +1412,6 @@ store_read_buffer_avail(png_store *ps)
 
    return 0;
 }
-#endif
 
 static int
 store_read_buffer_next(png_store *ps)
@@ -1331,6 +1463,240 @@ store_read_imp(png_store *ps, png_bytep pb, png_size_t st)
    }
 }
 
+static png_size_t
+store_read_chunk(png_store *ps, png_bytep pb, const png_size_t max,
+      const png_size_t min)
+{
+   png_uint_32 chunklen = ps->chunklen;
+   png_uint_32 chunktype = ps->chunktype;
+   png_uint_32 chunkpos = ps->chunkpos;
+   png_size_t st = max;
+
+   if (st > 0) do
+   {
+      if (chunkpos >= chunklen) /* end of last chunk */
+      {
+         png_byte buffer[8];
+
+         /* Read the header of the next chunk: */
+         store_read_imp(ps, buffer, 8U);
+         chunklen = png_get_uint_32(buffer) + 12U;
+         chunktype = png_get_uint_32(buffer+4U);
+         chunkpos = 0U; /* Position read so far */
+      }
+
+      if (chunktype == CHUNK_IDAT)
+      {
+         png_uint_32 IDAT_pos = ps->IDAT_pos;
+         png_uint_32 IDAT_len = ps->IDAT_len;
+         png_uint_32 IDAT_size = ps->IDAT_size;
+
+         /* The IDAT headers are constructed here; skip the input header. */
+         if (chunkpos < 8U)
+            chunkpos = 8U;
+
+         if (IDAT_pos == IDAT_len)
+         {
+            png_byte random = random_byte();
+
+            /* Make a new IDAT chunk, if IDAT_len is 0 this is the first IDAT,
+             * if IDAT_size is 0 this is the end.  At present this is set up
+             * using a random number so that there is a 25% chance before
+             * the start of the first IDAT chunk being 0 length.
+             */
+            if (IDAT_len == 0U) /* First IDAT */
+            {
+               switch (random & 3U)
+               {
+                  case 0U: IDAT_len = 12U; break; /* 0 bytes */
+                  case 1U: IDAT_len = 13U; break; /* 1 byte */
+                  default: IDAT_len = random_u32();
+                           IDAT_len %= IDAT_size;
+                           IDAT_len += 13U; /* 1..IDAT_size bytes */
+                           break;
+               }
+            }
+
+            else if (IDAT_size == 0U) /* all IDAT data read */
+            {
+               /* The last (IDAT) chunk should be positioned at the CRC now: */
+               if (chunkpos != chunklen-4U)
+                  png_error(ps->pread, "internal: IDAT size mismatch");
+
+               /* The only option here is to add a zero length IDAT, this
+                * happens 25% of the time.  Because of the check above
+                * chunklen-4U-chunkpos must be zero, we just need to skip the
+                * CRC now.
+                */
+               if ((random & 3U) == 0U)
+                  IDAT_len = 12U; /* Output another 0 length IDAT */
+
+               else
+               {
+                  /* End of IDATs, skip the CRC to make the code above load the
+                   * next chunk header next time round.
+                   */
+                  png_byte buffer[4];
+
+                  store_read_imp(ps, buffer, 4U);
+                  chunkpos += 4U;
+                  ps->IDAT_pos = IDAT_pos;
+                  ps->IDAT_len = IDAT_len;
+                  ps->IDAT_size = 0U;
+                  continue; /* Read the next chunk */
+               }
+            }
+
+            else
+            {
+               /* Middle of IDATs, use 'random' to determine the number of bits
+                * to use in the IDAT length.
+                */
+               IDAT_len = random_u32();
+               IDAT_len &= (1U << (1U + random % ps->IDAT_bits)) - 1U;
+               if (IDAT_len > IDAT_size)
+                  IDAT_len = IDAT_size;
+               IDAT_len += 12U; /* zero bytes may occur */
+            }
+
+            IDAT_pos = 0U;
+            ps->IDAT_crc = 0x35af061e; /* Ie: crc32(0UL, "IDAT", 4) */
+         } /* IDAT_pos == IDAT_len */
+
+         if (IDAT_pos < 8U) /* Return the header */ do
+         {
+            png_uint_32 b;
+            unsigned int shift;
+
+            if (IDAT_pos < 4U)
+               b = IDAT_len - 12U;
+
+            else
+               b = CHUNK_IDAT;
+
+            shift = 3U & IDAT_pos;
+            ++IDAT_pos;
+
+            if (shift < 3U)
+               b >>= 8U*(3U-shift);
+
+            *pb++ = 0xffU & b;
+         }
+         while (--st > 0 && IDAT_pos < 8);
+
+         else if (IDAT_pos < IDAT_len - 4U) /* I.e not the CRC */
+         {
+            if (chunkpos < chunklen-4U)
+            {
+               uInt avail = (uInt)-1;
+
+               if (avail > (IDAT_len-4U) - IDAT_pos)
+                  avail = (uInt)/*SAFE*/((IDAT_len-4U) - IDAT_pos);
+
+               if (avail > st)
+                  avail = (uInt)/*SAFE*/st;
+
+               if (avail > (chunklen-4U) - chunkpos)
+                  avail = (uInt)/*SAFE*/((chunklen-4U) - chunkpos);
+
+               store_read_imp(ps, pb, avail);
+               ps->IDAT_crc = crc32(ps->IDAT_crc, pb, avail);
+               pb += (png_size_t)/*SAFE*/avail;
+               st -= (png_size_t)/*SAFE*/avail;
+               chunkpos += (png_uint_32)/*SAFE*/avail;
+               IDAT_size -= (png_uint_32)/*SAFE*/avail;
+               IDAT_pos += (png_uint_32)/*SAFE*/avail;
+            }
+
+            else /* skip the input CRC */
+            {
+               png_byte buffer[4];
+
+               store_read_imp(ps, buffer, 4U);
+               chunkpos += 4U;
+            }
+         }
+
+         else /* IDAT crc */ do
+         {
+            uLong b = ps->IDAT_crc;
+            unsigned int shift = (IDAT_len - IDAT_pos); /* 4..1 */
+            ++IDAT_pos;
+
+            if (shift > 1U)
+               b >>= 8U*(shift-1U);
+
+            *pb++ = 0xffU & b;
+         }
+         while (--st > 0 && IDAT_pos < IDAT_len);
+
+         ps->IDAT_pos = IDAT_pos;
+         ps->IDAT_len = IDAT_len;
+         ps->IDAT_size = IDAT_size;
+      }
+
+      else /* !IDAT */
+      {
+         /* If there is still some pending IDAT data after the IDAT chunks have
+          * been processed there is a problem:
+          */
+         if (ps->IDAT_len > 0 && ps->IDAT_size > 0)
+            png_error(ps->pread, "internal: missing IDAT data");
+
+         if (chunktype == CHUNK_IEND && ps->IDAT_len == 0U)
+            png_error(ps->pread, "internal: missing IDAT");
+
+         if (chunkpos < 8U) /* Return the header */ do
+         {
+            png_uint_32 b;
+            unsigned int shift;
+
+            if (chunkpos < 4U)
+               b = chunklen - 12U;
+
+            else
+               b = chunktype;
+
+            shift = 3U & chunkpos;
+            ++chunkpos;
+
+            if (shift < 3U)
+               b >>= 8U*(3U-shift);
+
+            *pb++ = 0xffU & b;
+         }
+         while (--st > 0 && chunkpos < 8);
+
+         else /* Return chunk bytes, including the CRC */
+         {
+            png_size_t avail = st;
+
+            if (avail > chunklen - chunkpos)
+               avail = (png_size_t)/*SAFE*/(chunklen - chunkpos);
+
+            store_read_imp(ps, pb, avail);
+            pb += avail;
+            st -= avail;
+            chunkpos += (png_uint_32)/*SAFE*/avail;
+
+            /* Check for end of chunk and end-of-file; don't try to read a new
+             * chunk header at this point unless instructed to do so by 'min'.
+             */
+            if (chunkpos >= chunklen && max-st >= min &&
+                     store_read_buffer_avail(ps) == 0)
+               break;
+         }
+      } /* !IDAT */
+   }
+   while (st > 0);
+
+   ps->chunklen = chunklen;
+   ps->chunktype = chunktype;
+   ps->chunkpos = chunkpos;
+
+   return st; /* space left */
+}
+
 static void PNGCBAPI
 store_read(png_structp ppIn, png_bytep pb, png_size_t st)
 {
@@ -1340,26 +1706,33 @@ store_read(png_structp ppIn, png_bytep pb, png_size_t st)
    if (ps == NULL || ps->pread != pp)
       png_error(pp, "bad store read call");
 
-   store_read_imp(ps, pb, st);
+   store_read_chunk(ps, pb, st, st);
 }
 
 static void
 store_progressive_read(png_store *ps, png_structp pp, png_infop pi)
 {
-   /* Notice that a call to store_read will cause this function to fail because
-    * readpos will be set.
-    */
    if (ps->pread != pp || ps->current == NULL || ps->next == NULL)
       png_error(pp, "store state damaged (progressive)");
 
-   do
+   /* This is another Horowitz and Hill random noise generator.  In this case
+    * the aim is to stress the progressive reader with truly horrible variable
+    * buffer sizes in the range 1..500, so a sequence of 9 bit random numbers
+    * is generated.  We could probably just count from 1 to 32767 and get as
+    * good a result.
+    */
+   while (store_read_buffer_avail(ps) > 0)
    {
-      if (ps->readpos != 0)
-         png_error(pp, "store_read called during progressive read");
+      static png_uint_32 noise = 2;
+      png_size_t cb;
+      png_byte buffer[512];
 
-      png_process_data(pp, pi, ps->next->buffer, store_read_buffer_size(ps));
+      /* Generate 15 more bits of stuff: */
+      noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff);
+      cb = noise & 0x1ff;
+      cb -= store_read_chunk(ps, buffer, cb, 1);
+      png_process_data(pp, pi, buffer, cb);
    }
-   while (store_read_buffer_next(ps));
 }
 #endif /* PNG_READ_SUPPORTED */
 
@@ -1730,6 +2103,11 @@ store_read_reset(png_store *ps)
    ps->next = NULL;
    ps->readpos = 0;
    ps->validated = 0;
+
+   ps->chunkpos = 8;
+   ps->chunktype = 0;
+   ps->chunklen = 16;
+   ps->IDAT_size = 0;
 }
 
 #ifdef PNG_READ_SUPPORTED
@@ -1744,6 +2122,11 @@ store_read_set(png_store *ps, png_uint_32 id)
       {
          ps->current = pf;
          ps->next = NULL;
+         ps->IDAT_size = pf->IDAT_size;
+         ps->IDAT_bits = pf->IDAT_bits; /* just a cache */
+         ps->IDAT_len = 0;
+         ps->IDAT_pos = 0;
+         ps->IDAT_crc = 0UL;
          store_read_buffer_next(ps);
          return;
       }
@@ -2581,17 +2964,6 @@ modifier_color_encoding_is_set(const png_modifier *pm)
    return pm->current_gamma != 0;
 }
 
-/* Convenience macros. */
-#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d))
-#define CHUNK_IHDR CHUNK(73,72,68,82)
-#define CHUNK_PLTE CHUNK(80,76,84,69)
-#define CHUNK_IDAT CHUNK(73,68,65,84)
-#define CHUNK_IEND CHUNK(73,69,78,68)
-#define CHUNK_cHRM CHUNK(99,72,82,77)
-#define CHUNK_gAMA CHUNK(103,65,77,65)
-#define CHUNK_sBIT CHUNK(115,66,73,84)
-#define CHUNK_sRGB CHUNK(115,82,71,66)
-
 /* The guts of modification are performed during a read. */
 static void
 modifier_crc(png_bytep buffer)
@@ -2631,7 +3003,7 @@ modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
       {
          static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 };
          case modifier_start:
-            store_read_imp(&pm->this, pm->buffer, 8); /* size of signature. */
+            store_read_chunk(&pm->this, pm->buffer, 8, 8); /* signature. */
             pm->buffer_count = 8;
             pm->buffer_position = 0;
 
@@ -2641,7 +3013,7 @@ modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
             break;
 
          case modifier_signature:
-            store_read_imp(&pm->this, pm->buffer, 13+12); /* size of IHDR */
+            store_read_chunk(&pm->this, pm->buffer, 13+12, 13+12); /* IHDR */
             pm->buffer_count = 13+12;
             pm->buffer_position = 0;
 
@@ -2682,7 +3054,7 @@ modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
             {
                if (cb > st) cb = st;
                pm->flush -= cb;
-               store_read_imp(&pm->this, pb, cb);
+               store_read_chunk(&pm->this, pb, cb, cb);
                pb += cb;
                st -= cb;
                if (st == 0) return;
@@ -2699,7 +3071,7 @@ modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
                pm->pending_chunk = 0;
             }
             else
-               store_read_imp(&pm->this, pm->buffer, 8);
+               store_read_chunk(&pm->this, pm->buffer, 8, 8);
 
             pm->buffer_count = 8;
             pm->buffer_position = 0;
@@ -2765,8 +3137,8 @@ modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
              */
             if (len+12 <= sizeof pm->buffer)
             {
-               store_read_imp(&pm->this, pm->buffer+pm->buffer_count,
-                   len+12-pm->buffer_count);
+               png_size_t s = len+12-pm->buffer_count;
+               store_read_chunk(&pm->this, pm->buffer+pm->buffer_count, s, s);
                pm->buffer_count = len+12;
 
                /* Check for a modification, else leave it be. */
@@ -3333,8 +3705,8 @@ set_random_tRNS(png_structp pp, png_infop pi, const png_byte colour_type,
    {
       if (bit_depth == 8)
       {
-         R16(tRNS.red);
-         R16(tRNS.green);
+         tRNS.red = random_u16();
+         tRNS.green = random_u16();
          tRNS.blue = tRNS.red ^ tRNS.green;
          tRNS.red &= mask;
          tRNS.green &= mask;
@@ -3343,7 +3715,7 @@ set_random_tRNS(png_structp pp, png_infop pi, const png_byte colour_type,
 
       else /* bit_depth == 16 */
       {
-         R16(tRNS.red);
+         tRNS.red = random_u16();
          tRNS.green = (png_uint_16)(tRNS.red * 257);
          tRNS.blue = (png_uint_16)(tRNS.green * 17);
       }
@@ -3351,7 +3723,7 @@ set_random_tRNS(png_structp pp, png_infop pi, const png_byte colour_type,
 
    else
    {
-      R16(tRNS.gray);
+      tRNS.gray = random_u16();
       tRNS.gray &= mask;
    }
 
@@ -3638,8 +4010,11 @@ check_interlace_type(int const interlace_type)
 #  define do_own_interlace 1
 #endif /* WRITE_INTERLACING tests */
 
-#define CAN_WRITE_INTERLACE\
-   PNG_LIBPNG_VER >= 10700 || defined PNG_WRITE_INTERLACING_SUPPORTED
+#if PNG_LIBPNG_VER >= 10700 || defined PNG_WRITE_INTERLACING_SUPPORTED
+#   define CAN_WRITE_INTERLACE 1
+#else
+#   define CAN_WRITE_INTERLACE 0
+#endif
 
 /* Do the same thing for read interlacing; this controls whether read tests do
  * their own de-interlace or use libpng.
@@ -7303,7 +7678,7 @@ image_transform_png_set_rgb_to_gray_ini(const image_transform *this,
       png_uint_32 ru;
       double total;
 
-      R32_1(ru);
+      ru = random_u32();
       data.green_coefficient = total = (ru & 0xffff) / 65535.;
       ru >>= 16;
       data.red_coefficient = (1 - total) * (ru & 0xffff) / 65535.;
@@ -8231,7 +8606,7 @@ image_transform_png_set_filler_set(const image_transform *this,
     * filler.  The 'filler' value has all 32 bits set, but only bit_depth
     * will be used.  At this point we don't know bit_depth.
     */
-   R32(data.filler);
+   data.filler = random_u32();
    data.flags = random_choice();
 
    png_set_filler(pp, data.filler, data.flags);
@@ -8304,7 +8679,7 @@ image_transform_png_set_add_alpha_set(const image_transform *this,
     * filler.  The 'filler' value has all 32 bits set, but only bit_depth
     * will be used.  At this point we don't know bit_depth.
     */
-   R32(data.filler);
+   data.filler = random_u32();
    data.flags = random_choice();
 
    png_set_add_alpha(pp, data.filler, data.flags);
@@ -11054,23 +11429,36 @@ perform_interlace_macro_validation(void)
        */
       for (v=0;;)
       {
+         /* The first two tests overflow if the pass row or column is outside
+          * the possible range for a 32-bit result.  In fact the values should
+          * never be outside the range for a 31-bit result, but checking for 32
+          * bits here ensures that if an app uses a bogus pass row or column
+          * (just so long as it fits in a 32 bit integer) it won't get a
+          * possibly dangerous overflow.
+          */
          /* First the base 0 stuff: */
-         m = PNG_ROW_FROM_PASS_ROW(v, pass);
-         f = png_row_from_pass_row(v, pass);
-         if (m != f)
+         if (v < png_pass_rows(0xFFFFFFFFU, pass))
          {
-            fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n",
-               v, pass, m, f);
-            exit(99);
+            m = PNG_ROW_FROM_PASS_ROW(v, pass);
+            f = png_row_from_pass_row(v, pass);
+            if (m != f)
+            {
+               fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n",
+                  v, pass, m, f);
+               exit(99);
+            }
          }
 
-         m = PNG_COL_FROM_PASS_COL(v, pass);
-         f = png_col_from_pass_col(v, pass);
-         if (m != f)
+         if (v < png_pass_cols(0xFFFFFFFFU, pass))
          {
-            fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n",
-               v, pass, m, f);
-            exit(99);
+            m = PNG_COL_FROM_PASS_COL(v, pass);
+            f = png_col_from_pass_col(v, pass);
+            if (m != f)
+            {
+               fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n",
+                  v, pass, m, f);
+               exit(99);
+            }
          }
 
          m = PNG_ROW_IN_INTERLACE_PASS(v, pass);

contrib/libtests/timepng.c

@@ -2,7 +2,7 @@
  *
  * Copyright (c) 2013,2016 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.22 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.22 [May 26, 2016]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -44,8 +44,20 @@
 #  define voidcast(type, value) (value)
 #endif /* __cplusplus */
 
-#if ((defined(PNG_SEQUENTIAL_READ_SUPPORTED)) && defined(PNG_STDIO_SUPPORTED)\
-     && defined(PNG_EASY_ACCESS_SUPPORTED) && defined(PNG_INFO_IMAGE_SUPPORTED))
+/* 'CLOCK_PROCESS_CPUTIME_ID' is one of the clock timers for clock_gettime.  It
+ * need not be supported even when clock_gettime is available.  It returns the
+ * 'CPU' time the process has consumed.  'CPU' time is assumed to include time
+ * when the CPU is actually blocked by a pending cache fill but not time
+ * waiting for page faults.  The attempt is to get a measure of the actual time
+ * the implementation takes to read a PNG ignoring the potentially very large IO
+ * overhead.
+ */
+#if defined (CLOCK_PROCESS_CPUTIME_ID) && defined(PNG_STDIO_SUPPORTED) &&\
+    defined(PNG_EASY_ACCESS_SUPPORTED) &&\
+    (PNG_LIBPNG_VER >= 10700 ? defined(PNG_READ_PNG_SUPPORTED) :\
+     defined (PNG_SEQUENTIAL_READ_SUPPORTED) &&\
+     defined(PNG_INFO_IMAGE_SUPPORTED))
+
 typedef struct
 {
    FILE *input;

contrib/pngminus/png2pnm.c

@@ -1,8 +1,12 @@
 /*
  *  png2pnm.c --- conversion from PNG-file to PGM/PPM-file
- *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
+ *  copyright (C) 1999,2017 by Willem van Schaik <willem at schaik.com>
  *
  *  version 1.0 - 1999.10.15 - First version.
+ *          1.1 - 2017.04.22 - Add buffer-size check (Glenn Randers-Pehrson)
+ *          1.2 - 2017.08.24 - Fix potential overflow in buffer-size check
+ *                             (Glenn Randers-Pehrson)
+ *          1.3 - 2017.08.28 - Add PNGMINUS_UNUSED (Christian Hesse)
  *
  *  Permission to use, copy, modify, and distribute this software and
  *  its documentation for any purpose and without fee is hereby granted,
@@ -41,6 +45,7 @@
 #define PNG_DEBUG 0
 #endif
 
+
 #include "png.h"
 
 /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
@@ -48,11 +53,20 @@
 #  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
 #endif
 
+#ifndef PNGMINUS_UNUSED
+/* Unused formal parameter warnings are silenced using the following macro
+ * which is expected to have no bad effects on performance (optimizing
+ * compilers will probably remove it entirely).
+ */
+#  define PNGMINUS_UNUSED(param) (void)param
+#endif
+
 /* function prototypes */
 
 int  main (int argc, char *argv[]);
 void usage ();
-BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha);
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw,
+   BOOL alpha);
 
 /*
  *  main
@@ -85,7 +99,8 @@ int main(int argc, char *argv[])
           if ((fp_al = fopen (argv[argi], "wb")) == NULL)
           {
             fprintf (stderr, "PNM2PNG\n");
-            fprintf (stderr, "Error:  can not create alpha-channel file %s\n", argv[argi]);
+            fprintf (stderr, "Error:  can not create alpha-channel file %s\n",
+               argv[argi]);
             exit (1);
           }
           break;
@@ -176,9 +191,11 @@ void usage()
   fprintf (stderr, "Usage:  png2pnm [options] <file>.png [<file>.pnm]\n");
   fprintf (stderr, "   or:  ... | png2pnm [options]\n");
   fprintf (stderr, "Options:\n");
-  fprintf (stderr, "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
+  fprintf (stderr,
+     "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
   fprintf (stderr, "   -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
-  fprintf (stderr, "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
+  fprintf (stderr,
+     "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
   fprintf (stderr, "   -h | -?  print this help-information\n");
 }
 
@@ -186,7 +203,8 @@ void usage()
  *  png2pnm
  */
 
-BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha)
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
+    volatile BOOL raw, BOOL alpha)
 {
   png_struct    *png_ptr = NULL;
   png_info        *info_ptr = NULL;
@@ -218,7 +236,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
 
   /* create png and info structures */
 
-  png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING,
+  png_ptr = png_create_read_struct (png_get_libpng_ver(NULL),
     NULL, NULL, NULL);
   if (!png_ptr)
     return FALSE;   /* out of memory */
@@ -261,7 +279,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
     png_set_expand (png_ptr);
 
 #ifdef NJET
-  /* downgrade 16-bit images to 8 bit */
+  /* downgrade 16-bit images to 8-bit */
   if (bit_depth == 16)
     png_set_strip_16 (png_ptr);
   /* transform grayscale images into full-color */
@@ -315,12 +333,21 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
   /* row_bytes is the width x number of channels x (bit-depth / 8) */
   row_bytes = png_get_rowbytes (png_ptr, info_ptr);
 
-  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
+  if ((row_bytes == 0 || (size_t)height > ((size_t)(-1))/(size_t)row_bytes))
+  {
+    /* too big */ 
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
+  if ((png_pixels = (png_byte *)
+     malloc ((size_t)row_bytes * (size_t)height * sizeof (png_byte))) == NULL)
+  {
     png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
     return FALSE;
   }
 
-  if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+  if ((row_pointers = (png_byte **)
+     malloc ((size_t)height * sizeof (png_bytep))) == NULL)
   {
     png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
     free (png_pixels);
@@ -329,7 +356,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
   }
 
   /* set the individual row_pointers to point at the correct offsets */
-  for (i = 0; i < (height); i++)
+  for (i = 0; i < ((int) height); i++)
     row_pointers[i] = png_pixels + i * row_bytes;
 
   /* now we can go ahead and just read the whole image */
@@ -372,9 +399,9 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
   /* write data to PNM file */
   pix_ptr = png_pixels;
 
-  for (row = 0; row < height; row++)
+  for (row = 0; row < (int) height; row++)
   {
-    for (col = 0; col < width; col++)
+    for (col = 0; col < (int) width; col++)
     {
       for (i = 0; i < (channels - alpha_present); i++)
       {
@@ -401,7 +428,8 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
           if (raw)
             fputc ((int) *pix_ptr++ , alpha_file);
           else
-            if (bit_depth == 16){
+            if (bit_depth == 16)
+            {
               dep_16 = (long) *pix_ptr++;
               fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
             }
@@ -425,6 +453,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
   if (png_pixels != (unsigned char*) NULL)
     free (png_pixels);
 
+  PNGMINUS_UNUSED(raw); /* to quiet a Coverity defect */
   return TRUE;
 
 } /* end of source */

contrib/pngminus/pnm2png.c

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

contrib/tools/README.txt

@@ -23,4 +23,5 @@ ORIGINAL AUTHORS
     of the people below claim any rights with regard to the contents of this
     directory.
 
-    John Bowler <jbowler@acm.org>
+    John Bowler <jbowler at acm.org>
+    Glenn Randers-Pehrson <glennrp at users.sourceforge.net>

contrib/tools/chkfmt

@@ -1,4 +1,11 @@
 #!/bin/sh
+
+# chkfmt
+#
+# COPYRIGHT: Written by John Cunningham Bowler, 2010.
+# 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.
 #
 # Check the format of the source files in the current directory - checks for a
 # line length of 80 characters max and no tab characters.

contrib/tools/pngcp.c

@@ -1,34 +1,46 @@
 /* pngcp.c
  *
- * COPYRIGHT: Written by John Cunningham Bowler, 2016.
- * To the extent possible under law, the author has waived all copyright and
- * related or neighboring rights to this work.  This work is published from:
- * United States.
+ * Copyright (c) 2016 John Cunningham Bowler
  *
- * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
  *
- * This is a minimal example of copying a PNG without changes using the
- * png_read_png and png_write_png interfaces.
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This is an example of copying a PNG without changes using the png_read_png
+ * and png_write_png interfaces.  A considerable number of options are provided
+ * to manipulate the compression of the PNG data and other compressed chunks.
  *
  * For a more extensive example that uses the transforms see
  * contrib/libtests/pngimage.c in the libpng distribution.
  */
-#define _POSIX_SOURCE 1
-#include <stdarg.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <stdio.h>
-#include <limits.h>
-#include <assert.h>
+#include "pnglibconf.h" /* To find how libpng was configured. */
 
-#include <unistd.h>
-#include <sys/stat.h>
+#ifdef PNG_PNGCP_TIMING_SUPPORTED
+   /* WARNING:
+    *
+    * This test is here to allow POSIX.1b extensions to be used if enabled in
+    * the compile; specifically the code requires_POSIX_C_SOURCE support of
+    * 199309L or later to enable clock_gettime use.
+    *
+    * IF this causes problems THEN compile with a strict ANSI C compiler and let
+    * this code turn on the POSIX features that it minimally requires.
+    *
+    * IF this does not work there is probably a bug in your ANSI C compiler or
+    * your POSIX implementation.
+    */
+#  define _POSIX_C_SOURCE 199309L
+#else /* No timing support required */
+#  define _POSIX_SOURCE 1
+#endif
 
 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
 #  include <config.h>
 #endif
 
+#include <stdio.h>
+
 /* Define the following to use this test against your installed libpng, rather
  * than the one being built here:
  */
@@ -38,22 +50,6 @@
 #  include "../../png.h"
 #endif
 
-#include <zlib.h>
-
-#ifndef PNG_SETJMP_SUPPORTED
-#  include <setjmp.h> /* because png.h did *not* include this */
-#endif
-
-#ifdef __GNUC__
-   /* Many versions of GCC erroneously report that local variables unmodified
-    * within the scope of a setjmp may be clobbered.  This hacks round the
-    * problem (sometimes) without harming other compilers.
-    */
-#  define gv volatile
-#else
-#  define gv
-#endif
-
 #if PNG_LIBPNG_VER < 10700
    /* READ_PNG and WRITE_PNG were not defined, so: */
 #  ifdef PNG_INFO_IMAGE_SUPPORTED
@@ -67,6 +63,56 @@
 #endif /* pre 1.7.0 */
 
 #if (defined(PNG_READ_PNG_SUPPORTED)) && (defined(PNG_WRITE_PNG_SUPPORTED))
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+#include <assert.h>
+
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include <zlib.h>
+
+#ifndef PNG_SETJMP_SUPPORTED
+#  include <setjmp.h> /* because png.h did *not* include this */
+#endif
+
+#ifdef __cplusplus
+#  define voidcast(type, value) static_cast<type>(value)
+#else
+#  define voidcast(type, value) (value)
+#endif /* __cplusplus */
+
+#ifdef __GNUC__
+   /* Many versions of GCC erroneously report that local variables unmodified
+    * within the scope of a setjmp may be clobbered.  This hacks round the
+    * problem (sometimes) without harming other compilers.
+    */
+#  define gv volatile
+#else
+#  define gv
+#endif
+
+/* 'CLOCK_PROCESS_CPUTIME_ID' is one of the clock timers for clock_gettime.  It
+ * need not be supported even when clock_gettime is available.  It returns the
+ * 'CPU' time the process has consumed.  'CPU' time is assumed to include time
+ * when the CPU is actually blocked by a pending cache fill but not time
+ * waiting for page faults.  The attempt is to get a measure of the actual time
+ * the implementation takes to read a PNG ignoring the potentially very large IO
+ * overhead.
+ */
+#ifdef PNG_PNGCP_TIMING_SUPPORTED
+#  include <time.h>   /* clock_gettime and associated definitions */
+#  ifndef CLOCK_PROCESS_CPUTIME_ID
+      /* Prevent inclusion of the spurious code: */
+#     undef PNG_PNGCP_TIMING_SUPPORTED
+#  endif
+#endif /* PNGCP_TIMING */
+
+/* So if the timing feature has been activated: */
+
 /* This structure is used to control the test of a single file. */
 typedef enum
 {
@@ -92,6 +138,12 @@ typedef enum
 #define SIZES           0x080 /* Report input and output sizes */
 #define SEARCH          0x100 /* Search IDAT compression options */
 #define NOWRITE         0x200 /* Do not write an output file */
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#  define IGNORE_INDEX  0x400 /* Ignore out of range palette indices (BAD!) */
+#  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+#     define FIX_INDEX  0x800 /* 'Fix' out of range palette indices (OK) */
+#  endif /* GET_PALETTE_MAX */
+#endif /* CHECK_FOR_INVALID_INDEX */
 #define OPTION     0x80000000 /* Used for handling options */
 #define LIST       0x80000001 /* Used for handling options */
 
@@ -107,18 +159,36 @@ static const char range_lo[] = "low";
 static const char range_hi[] = "high";
 static const char all[] = "all";
 #define RANGE(lo,hi) { range_lo, lo }, { range_hi, hi }
-static const struct value_list
+typedef struct value_list
 {
    const char *name;  /* the command line name of the value */
    int         value; /* the actual value to use */
-}
+}  value_list;
+
+static const value_list
+#ifdef PNG_SW_COMPRESS_png_level
+vl_compression[] =
+{
+   /* Overall compression control.  The order controls the search order for
+    * 'all'.  Since the search is for the smallest the order used is low memory
+    * then high speed.
+    */
+   { "low-memory",      PNG_COMPRESSION_LOW_MEMORY },
+   { "high-speed",      PNG_COMPRESSION_HIGH_SPEED },
+   { "high-read-speed", PNG_COMPRESSION_HIGH_READ_SPEED },
+   { "low",             PNG_COMPRESSION_LOW },
+   { "medium",          PNG_COMPRESSION_MEDIUM },
+   { "old",             PNG_COMPRESSION_COMPAT },
+   { "high",            PNG_COMPRESSION_HIGH },
+   { all, 0 }
+},
+#endif /* SW_COMPRESS_png_level */
+
 #if defined(PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED) ||\
     defined(PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED)
 vl_strategy[] =
 {
-   /* This controls the order of search and also the default (which is RLE
-    * compression):
-    */
+   /* This controls the order of search. */
    { "huffman", Z_HUFFMAN_ONLY },
    { "RLE", Z_RLE },
    { "fixed", Z_FIXED }, /* the remainder do window searchs */
@@ -170,35 +240,33 @@ vl_filter[] =
    { "paeth",  PNG_FILTER_PAETH  }
 },
 #endif /* WRITE_FILTER */
-#define SELECT_HEURISTICALLY 1
-#define SELECT_METHODICALLY  2
-#if defined(PNG_SELECT_FILTER_HEURISTICALLY_SUPPORTED) ||\
-    defined(PNG_SELECT_FILTER_METHODICALLY_SUPPORTED)
-vl_select[] =
+#ifdef PNG_PNGCP_TIMING_SUPPORTED
+#  define PNGCP_TIME_READ  1
+#  define PNGCP_TIME_WRITE 2
+vl_time[] =
 {
-   { all,   SELECT_HEURISTICALLY|SELECT_METHODICALLY },
-   { "off", 0 },
-#ifdef PNG_SELECT_FILTER_HEURISTICALLY_SUPPORTED
-   { "heuristically", SELECT_HEURISTICALLY },
-#endif /* SELECT_FILTER_HEURISTICALLY */
-#ifdef PNG_SELECT_FILTER_METHODICALLY_SUPPORTED
-   { "methodically", SELECT_METHODICALLY },
-#endif /* SELECT_FILTER_METHODICALLY */
-   { "both", SELECT_HEURISTICALLY|SELECT_METHODICALLY }
+   { "both",  PNGCP_TIME_READ+PNGCP_TIME_WRITE },
+   { "off",   0 },
+   { "read",  PNGCP_TIME_READ },
+   { "write", PNGCP_TIME_WRITE }
 },
-#endif /* SELECT_FILTER_HEURISTICALLY || SELECT_FILTER_METHODICALLY */
-vl_IDAT_size[] = /* for png_set_compression_buffer_size */
+#endif /* PNGCP_TIMING */
+vl_IDAT_size[] = /* for png_set_IDAT_size */
 {
    { "default", 0x7FFFFFFF },
    { "minimal", 1 },
    RANGE(1, 0x7FFFFFFF)
 },
+#ifndef PNG_SW_IDAT_size
+   /* Pre 1.7 API: */
+#  define png_set_IDAT_size(p,v) png_set_compression_buffer_size(p, v)
+#endif /* !SW_IDAT_size */
 #define SL 8 /* stack limit in display, below */
 vl_log_depth[] = { { "on", 1 }, { "off", 0 }, RANGE(0, SL) },
-vl_on_off[] = { { "on", 1 }, { "off", 2 } };
+vl_on_off[] = { { "on", 1 }, { "off", 0 } };
 
 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
-static struct value_list
+static value_list
 vl_windowBits_IDAT[] =
 {
    { "default", MAX_WBITS },
@@ -208,14 +276,16 @@ vl_windowBits_IDAT[] =
 };
 #endif /* IDAT compression */
 
-static const struct option
+typedef struct option
 {
-   const char              *name;         /* name of the option */
-   png_uint_32              opt;          /* an option, or OPTION or LIST */
-   png_byte                 search;       /* Search on --search */
-   png_byte                 value_count;  /* length of the list of values: */
-   const struct value_list *values;       /* values for OPTION or LIST */
-}  options[] =
+   const char       *name;         /* name of the option */
+   png_uint_32       opt;          /* an option, or OPTION or LIST */
+   png_byte          search;       /* Search on --search */
+   png_byte          value_count;  /* length of the list of values: */
+   const value_list *values;       /* values for OPTION or LIST */
+}  option;
+
+static const option options[] =
 {
    /* struct display options, these are set when the command line is read */
 #  define S(n,v) { #n, v, 0, 2, vl_on_off },
@@ -229,19 +299,32 @@ static const struct option
    S(sizes,    SIZES)
    S(search,   SEARCH)
    S(nowrite,  NOWRITE)
+#  ifdef IGNORE_INDEX
+      S(ignore-palette-index, IGNORE_INDEX)
+#  endif /* IGNORE_INDEX */
+#  ifdef FIX_INDEX
+      S(fix-palette-index, FIX_INDEX)
+#  endif /* FIX_INDEX */
 #  undef S
 
    /* OPTION settings, these and LIST settings are read on demand */
 #  define VLNAME(name) vl_ ## name
-#  define VLSIZE(name) ((sizeof VLNAME(name))/(sizeof VLNAME(name)[0]))
+#  define VLSIZE(name) voidcast(png_byte,\
+                           (sizeof VLNAME(name))/(sizeof VLNAME(name)[0]))
 #  define VL(oname, name, type, search)\
    { oname, type, search, VLSIZE(name), VLNAME(name) },
 #  define VLO(oname, name, search) VL(oname, name, OPTION, search)
 
 #  ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
 #     define VLCIDAT(name) VLO(#name, name, 1/*search*/)
+#     ifdef PNG_SW_COMPRESS_level
+#        define VLCiCCP(name) VLO("ICC-profile-" #name, name, 0/*search*/)
+#     else
+#        define VLCiCCP(name)
+#     endif
 #  else
 #     define VLCIDAT(name)
+#     define VLCiCCP(name)
 #  endif /* WRITE_CUSTOMIZE_COMPRESSION */
 
 #  ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
@@ -250,10 +333,21 @@ static const struct option
 #     define VLCzTXt(name)
 #  endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
 
-#  define VLC(name) VLCIDAT(name) VLCzTXt(name)
+#  define VLC(name) VLCIDAT(name) VLCiCCP(name) VLCzTXt(name)
 
+#  ifdef PNG_SW_COMPRESS_png_level
+      /* The libpng compression level isn't searched beause it justs sets the
+       * other things that are searched!
+       */
+      VLO("compression", compression, 0)
+      VLO("text-compression", compression, 0)
+      VLO("ICC-profile-compression", compression, 0)
+#  endif /* SW_COMPRESS_png_level */
    VLC(strategy)
    VLO("windowBits", windowBits_IDAT, 1)
+#  ifdef PNG_SW_COMPRESS_windowBits
+      VLO("ICC-profile-windowBits", windowBits_text/*sic*/, 0)
+#  endif
    VLO("text-windowBits", windowBits_text, 0)
    VLC(level)
    VLC(memLevel)
@@ -264,18 +358,21 @@ static const struct option
 
    /* LIST settings */
 #  define VLL(name, search) VL(#name, name, LIST, search)
-#if defined(PNG_SELECT_FILTER_HEURISTICALLY_SUPPORTED) ||\
-    defined(PNG_SELECT_FILTER_METHODICALLY_SUPPORTED)
-   VLL(select, 1)
-#endif /* SELECT_FILTER_HEURISTICALLY || SELECT_FILTER_METHODICALLY */
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    VLL(filter, 0)
 #endif /* WRITE_FILTER */
+#ifdef PNG_PNGCP_TIMING_SUPPORTED
+   VLL(time, 0)
+#endif /* PNGCP_TIMING */
 #  undef VLL
 #  undef VL
 };
 
-#define opt_count ((sizeof options)/(sizeof options[0]))
+#ifdef __cplusplus
+   static const size_t option_count((sizeof options)/(sizeof options[0]));
+#else /* !__cplusplus */
+#  define option_count ((sizeof options)/(sizeof options[0]))
+#endif /* !__cplusplus */
 
 static const char *
 cts(int ct)
@@ -309,12 +406,19 @@ struct display
    png_alloc_size_t read_size;
    png_structp      read_pp;
    png_infop        ip;
-#  if PNG_LIBPNG_VER < 10700
+#  if PNG_LIBPNG_VER < 10700 && defined PNG_TEXT_SUPPORTED
       png_textp     text_ptr; /* stash of text chunks */
       int           num_text;
       int           text_stashed;
 #  endif /* pre 1.7 */
 
+#  ifdef PNG_PNGCP_TIMING_SUPPORTED
+      struct timespec   read_time;
+      struct timespec   read_time_total;
+      struct timespec   write_time;
+      struct timespec   write_time_total;
+#  endif /* PNGCP_TIMING */
+
    /* Used to write a new image (the original info_ptr is used) */
 #  define MAX_SIZE ((png_alloc_size_t)(-1))
    png_alloc_size_t write_size;
@@ -331,12 +435,12 @@ struct display
    int              min_windowBits;    /* The windowBits range is 8..8 */
 
    /* Options handling */
-   png_uint_32      results;           /* A mask of errors seen */
-   png_uint_32      options;           /* See display_log below */
-   png_byte         entry[opt_count];  /* The selected entry+1 of an option that
-                                        * appears on the command line, or 0 if
-                                        * it was not given. */
-   int              value[opt_count];  /* Corresponding value */
+   png_uint_32      results;             /* A mask of errors seen */
+   png_uint_32      options;             /* See display_log below */
+   png_byte         entry[option_count]; /* The selected entry+1 of an option
+                                          * that appears on the command line, or
+                                          * 0 if it was not given. */
+   int              value[option_count]; /* Corresponding value */
 
    /* Compression exhaustive testing */
    /* Temporary variables used only while testing a single collection of
@@ -371,7 +475,7 @@ struct display
    char             curr[32*SL];       /* current options being tested */
    char             best[32*SL];       /* best options */
 
-   char             namebuf[FILENAME_MAX+1]; /* output file name */
+   char             namebuf[FILENAME_MAX]; /* output file name */
 };
 
 static void
@@ -391,7 +495,7 @@ display_init(struct display *dp)
    dp->ip = NULL;
    dp->write_pp = NULL;
    dp->min_windowBits = -1; /* this is an OPTIND, so -1 won't match anything */
-#  if PNG_LIBPNG_VER < 10700
+#  if PNG_LIBPNG_VER < 10700 && defined PNG_TEXT_SUPPORTED
       dp->text_ptr = NULL;
       dp->num_text = 0;
       dp->text_stashed = 0;
@@ -433,7 +537,7 @@ display_clean(struct display *dp)
    display_clean_write(dp);
    dp->output_file = NULL;
 
-#  if PNG_LIBPNG_VER < 10700
+#  if PNG_LIBPNG_VER < 10700 && defined PNG_TEXT_SUPPORTED
       /* This is actually created and used by the write code, but only
        * once; it has to be retained for subsequent writes of the same file.
        */
@@ -534,7 +638,7 @@ display_log(struct display *dp, error_level level, const char *fmt, ...)
    }
 }
 
-#if PNG_LIBPNG_VER < 10700
+#if PNG_LIBPNG_VER < 10700 && defined PNG_TEXT_SUPPORTED
 static void
 text_stash(struct display *dp)
 {
@@ -562,7 +666,7 @@ text_stash(struct display *dp)
 
    if (dp->num_text > 0)
    {
-      dp->text_ptr = malloc(dp->num_text * sizeof *chunks);
+      dp->text_ptr = voidcast(png_textp, malloc(dp->num_text * sizeof *chunks));
 
       if (dp->text_ptr == NULL)
          display_log(dp, APP_ERROR, "text chunks: stash malloc failed");
@@ -605,7 +709,7 @@ text_restore(struct display *dp)
  *       Set an option to a bitmask constructed from the values (List)
  */
 static png_byte
-optind(struct display *dp, const char *opt, size_t len)
+option_index(struct display *dp, const char *opt, size_t len)
    /* Return the index (in options[]) of the given option, outputs an error if
     * it does not exist.  Takes the name of the option and a length (number of
     * characters in the name).
@@ -613,7 +717,7 @@ optind(struct display *dp, const char *opt, size_t len)
 {
    png_byte j;
 
-   for (j=0; j<opt_count; ++j)
+   for (j=0; j<option_count; ++j)
       if (strncmp(options[j].name, opt, len) == 0 && options[j].name[len] == 0)
          return j;
 
@@ -626,12 +730,12 @@ optind(struct display *dp, const char *opt, size_t len)
 }
 
 /* This works for an option name (no quotes): */
-#define OPTIND(dp, name) optind(dp, #name, (sizeof #name)-1)
+#define OPTIND(dp, name) option_index(dp, #name, (sizeof #name)-1)
 
 static int
-getopt(struct display *dp, const char *opt, int *value)
+get_option(struct display *dp, const char *opt, int *value)
 {
-   const png_byte i = optind(dp, opt, strlen(opt));
+   const png_byte i = option_index(dp, opt, strlen(opt));
 
    if (dp->entry[i]) /* option was set on command line */
    {
@@ -1147,7 +1251,7 @@ getallopts_(struct display *dp, const png_byte opt, int *value, int record)
 static int
 getallopts(struct display *dp, const char *opt_str, int *value)
 {
-   return getallopts_(dp, optind(dp, opt_str, strlen(opt_str)), value, 0);
+   return getallopts_(dp, option_index(dp, opt_str, strlen(opt_str)), value, 0);
 }
 
 static int
@@ -1155,7 +1259,7 @@ getsearchopts(struct display *dp, const char *opt_str, int *value)
    /* As above except that if the option was not set try a search */
 {
    png_byte istrat;
-   const png_byte opt = optind(dp, opt_str, strlen(opt_str));
+   const png_byte opt = option_index(dp, opt_str, strlen(opt_str));
    int record = options[opt].search;
    const char *entry_name;
 
@@ -1172,17 +1276,6 @@ getsearchopts(struct display *dp, const char *opt_str, int *value)
    istrat = OPTIND(dp, strategy);
    entry_name = range_lo; /* record the value, not the name */
 
-#if defined(PNG_SELECT_FILTER_HEURISTICALLY_SUPPORTED) ||\
-    defined(PNG_SELECT_FILTER_METHODICALLY_SUPPORTED)
-   if (opt == OPTIND(dp, select))
-   {
-      dp->value[opt] = SELECT_METHODICALLY; /* should probably be all */
-      entry_name = "methodically"; /* for the moment */
-   }
-
-   else
-#endif /* SELECT_FILTER_HEURISTICALLY || SELECT_FILTER_METHODICALLY */
-
    if (opt == istrat) /* search all strategies */
       (void)advance_opt(dp, opt, 0/*iterate*/), record=0;
 
@@ -1223,7 +1316,7 @@ getsearchopts(struct display *dp, const char *opt_str, int *value)
    }
 
    else /* something else */
-      assert(!"reached");
+      assert(0=="reached");
 
    if (record)
       record_opt(dp, opt, entry_name);
@@ -1235,8 +1328,9 @@ getsearchopts(struct display *dp, const char *opt_str, int *value)
 
 static int
 find_val(struct display *dp, png_byte opt, const char *str, size_t len)
-   /* Like optind but sets (index+i) of the entry in options[opt] that matches
-    * str[0..len-1] into dp->entry[opt] as well as returning the actual value.
+   /* Like option_index but sets (index+i) of the entry in options[opt] that
+    * matches str[0..len-1] into dp->entry[opt] as well as returning the actual
+    * value.
     */
 {
    int rlo = INT_MAX, rhi = INT_MIN;
@@ -1297,7 +1391,7 @@ opt_check(struct display *dp, const char *arg)
       /* So arg[0..i-1] is the argument name, this does not return if this isn't
        * a valid option name.
        */
-      j = optind(dp, arg, i);
+      j = option_index(dp, arg, i);
 
       /* It matcheth an option; check the remainder. */
       if (arg[i] == 0) /* no specified value, use the default */
@@ -1401,6 +1495,83 @@ opt_check(struct display *dp, const char *arg)
       return 0; /* not an option */
 }
 
+#ifdef PNG_PNGCP_TIMING_SUPPORTED
+static void
+set_timer(struct display *dp, struct timespec *timer)
+{
+   /* Do the timing using clock_gettime and the per-process timer. */
+   if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, timer))
+   {
+      display_log(dp, APP_ERROR,
+            "CLOCK_PROCESS_CPUTIME_ID: %s: timing disabled\n", strerror(errno));
+      dp->value[OPTIND(dp,time)] = 0; /* i.e. off */
+   }
+}
+
+static void
+start_timer(struct display *dp, int what)
+{
+   if ((dp->value[OPTIND(dp,time)] & what) != 0)
+      set_timer(dp, what == PNGCP_TIME_READ ? &dp->read_time : &dp->write_time);
+}
+
+static void
+end_timer(struct display *dp, int what)
+{
+   if ((dp->value[OPTIND(dp,time)] & what) != 0)
+   {
+      struct timespec t, tmp;
+
+      set_timer(dp, &t);
+
+      if (what == PNGCP_TIME_READ)
+         tmp = dp->read_time;
+
+      else
+         tmp = dp->write_time;
+
+      t.tv_sec -= tmp.tv_sec;
+      t.tv_nsec -= tmp.tv_nsec;
+
+      if (t.tv_nsec < 0)
+      {
+         --(t.tv_sec);
+         t.tv_nsec += 1000000000L;
+      }
+
+      if (what == PNGCP_TIME_READ)
+         dp->read_time = t, tmp = dp->read_time_total;
+
+      else
+         dp->write_time = t, tmp = dp->write_time_total;
+
+      tmp.tv_sec += t.tv_sec;
+      tmp.tv_nsec += t.tv_nsec;
+
+      if (tmp.tv_nsec >= 1000000000L)
+      {
+         ++(tmp.tv_sec);
+         tmp.tv_nsec -= 1000000000L;
+      }
+
+      if (what == PNGCP_TIME_READ)
+         dp->read_time_total = tmp;
+
+      else
+         dp->write_time_total = tmp;
+   }
+}
+
+static void
+print_time(const char *what, struct timespec t)
+{
+   printf("%s %.2lu.%.9ld", what, (unsigned long)t.tv_sec, t.tv_nsec);
+}
+#else /* !PNGCP_TIMING */
+#define start_timer(dp, what) ((void)0)
+#define end_timer(dp, what) ((void)0)
+#endif /* !PNGCP_TIMING */
+
 /* The following is used in main to verify that the final argument is a
  * directory:
  */
@@ -1468,7 +1639,7 @@ makename(struct display *dp, const char *dir, const char *infile)
    {
       size_t dsize = strlen(dir);
 
-      if (dsize < FILENAME_MAX+2)
+      if (dsize <= (sizeof dp->namebuf)-2) /* Allow for name + '/' + '\0' */
       {
          size_t isize = strlen(infile);
          size_t istart = isize-1;
@@ -1488,7 +1659,7 @@ makename(struct display *dp, const char *dir, const char *infile)
          isize -= istart;
          infile += istart;
 
-         if (dsize+isize <= FILENAME_MAX)
+         if (dsize+isize < (sizeof dp->namebuf)) /* dsize + infile + '\0' */
          {
             memcpy(dp->namebuf+dsize, infile, isize+1);
 
@@ -1499,7 +1670,7 @@ makename(struct display *dp, const char *dir, const char *infile)
 
          else
          {
-            dp->namebuf[dsize] = 0;
+            dp->namebuf[dsize] = 0; /* allowed for: -2 at start */
             display_log(dp, USER_ERROR, "%s%s: output file name too long",
                   dp->namebuf, infile);
          }
@@ -1558,7 +1729,7 @@ read_function(png_structp pp, png_bytep data, png_size_t size)
 {
    struct display *dp = get_dp(pp);
 
-   if (fread(data, size, 1U, dp->fp) == 1U)
+   if (size == 0U || fread(data, size, 1U, dp->fp) == 1U)
       dp->read_size += size;
 
    else
@@ -1582,7 +1753,21 @@ read_png(struct display *dp, const char *filename)
    if (dp->read_pp == NULL)
       display_log(dp, LIBPNG_ERROR, "failed to create read struct");
 
-   png_set_benign_errors(dp->read_pp, 1/*allowed*/);
+#  ifdef PNG_BENIGN_ERRORS_SUPPORTED
+      png_set_benign_errors(dp->read_pp, 1/*allowed*/);
+#  endif /* BENIGN_ERRORS */
+
+#  ifdef FIX_INDEX
+      if ((dp->options & FIX_INDEX) != 0)
+         png_set_check_for_invalid_index(dp->read_pp, 1/*on, no warning*/);
+#     ifdef IGNORE_INDEX
+         else
+#     endif /* IGNORE_INDEX */
+#  endif /* FIX_INDEX */
+#  ifdef IGNORE_INDEX
+      if ((dp->options & IGNORE_INDEX) != 0) /* DANGEROUS */
+         png_set_check_for_invalid_index(dp->read_pp, -1/*off completely*/);
+#  endif /* IGNORE_INDEX */
 
    /* The png_read_png API requires us to make the info struct, but it does the
     * call to png_read_info.
@@ -1594,10 +1779,10 @@ read_png(struct display *dp, const char *filename)
    /* Set the IO handling */
    png_set_read_fn(dp->read_pp, dp, read_function);
 
-#  ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+#  ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
       png_set_keep_unknown_chunks(dp->read_pp, PNG_HANDLE_CHUNK_ALWAYS, NULL,
             0);
-#  endif /* SET_UNKNOWN_CHUNKS */
+#  endif /* HANDLE_AS_UNKNOWN */
 
 #  ifdef PNG_SET_USER_LIMITS_SUPPORTED
       /* Remove the user limits, if any */
@@ -1605,15 +1790,24 @@ read_png(struct display *dp, const char *filename)
 #  endif /* SET_USER_LIMITS */
 
    /* Now read the PNG. */
+   start_timer(dp, PNGCP_TIME_READ);
    png_read_png(dp->read_pp, dp->ip, 0U/*transforms*/, NULL/*params*/);
+   end_timer(dp, PNGCP_TIME_READ);
    dp->w = png_get_image_width(dp->read_pp, dp->ip);
    dp->h = png_get_image_height(dp->read_pp, dp->ip);
    dp->ct = png_get_color_type(dp->read_pp, dp->ip);
    dp->bpp = png_get_bit_depth(dp->read_pp, dp->ip) *
              png_get_channels(dp->read_pp, dp->ip);
    {
+      /* png_get_rowbytes should never return 0 because the value is set by the
+       * first call to png_set_IHDR, which should have happened by now, but just
+       * in case:
+       */
       png_alloc_size_t rb = png_get_rowbytes(dp->read_pp, dp->ip);
 
+      if (rb == 0)
+         png_error(dp->read_pp, "invalid row byte count from libpng");
+
       /* The size calc can overflow. */
       if ((MAX_SIZE-dp->h)/rb < dp->h)
          png_error(dp->read_pp, "image too large");
@@ -1621,6 +1815,39 @@ read_png(struct display *dp, const char *filename)
       dp->size = rb * dp->h + dp->h/*filter byte*/;
    }
 
+#ifdef FIX_INDEX
+   if (dp->ct == PNG_COLOR_TYPE_PALETTE && (dp->options & FIX_INDEX) != 0)
+   {
+      int max = png_get_palette_max(dp->read_pp, dp->ip);
+      png_colorp palette = NULL;
+      int num = -1;
+
+      if (png_get_PLTE(dp->read_pp, dp->ip, &palette, &num) != PNG_INFO_PLTE
+          || max < 0 || num <= 0 || palette == NULL)
+         display_log(dp, LIBPNG_ERROR, "invalid png_get_PLTE result");
+
+      if (max >= num)
+      {
+         /* 'Fix' the palette. */
+         int i;
+         png_color newpal[256];
+
+         for (i=0; i<num; ++i)
+            newpal[i] = palette[i];
+
+         /* Fill in any remainder with a warning color: */
+         for (; i<=max; ++i)
+         {
+            newpal[i].red = 0xbe;
+            newpal[i].green = 0xad;
+            newpal[i].blue = 0xed;
+         }
+
+         png_set_PLTE(dp->read_pp, dp->ip, newpal, i);
+      }
+   }
+#endif /* FIX_INDEX */
+
    display_clean_read(dp);
    dp->operation = "none";
 }
@@ -1709,9 +1936,25 @@ set_compression(struct display *dp)
    SET_COMPRESSION
 #  undef SET
 }
+
+#ifdef PNG_SW_COMPRESS_level /* 1.7.0+ */
+static void
+set_ICC_profile_compression(struct display *dp)
+{
+   int val;
+
+#  define SET(name, func) if (getallopts(dp, "ICC-profile-" #name, &val))\
+      png_set_ICC_profile_compression_ ## func(dp->write_pp, val);
+   SET_COMPRESSION
+#  undef SET
+}
+#else
+#  define set_ICC_profile_compression(dp) ((void)0)
+#endif
 #else
 #  define search_compression(dp) ((void)0)
 #  define set_compression(dp) ((void)0)
+#  define set_ICC_profile_compression(dp) ((void)0)
 #endif /* WRITE_CUSTOMIZE_COMPRESSION */
 
 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
@@ -1741,19 +1984,27 @@ write_png(struct display *dp, const char *destname)
    if (dp->write_pp == NULL)
       display_log(dp, LIBPNG_ERROR, "failed to create write png_struct");
 
-   png_set_benign_errors(dp->write_pp, 1/*allowed*/);
+#  ifdef PNG_BENIGN_ERRORS_SUPPORTED
+      png_set_benign_errors(dp->write_pp, 1/*allowed*/);
+#  endif /* BENIGN_ERRORS */
+
    png_set_write_fn(dp->write_pp, dp, write_function, NULL/*flush*/);
 
+#ifdef IGNORE_INDEX
+   if ((dp->options & IGNORE_INDEX) != 0) /* DANGEROUS */
+      png_set_check_for_invalid_index(dp->write_pp, -1/*off completely*/);
+#endif /* IGNORE_INDEX */
+
    /* Restore the text chunks when using libpng 1.6 or less; this is a macro
     * which expands to nothing in 1.7+  In earlier versions it tests
     * dp->text_stashed, which is only set (below) *after* the first write.
     */
    text_restore(dp);
 
-#  ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+#  ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
       png_set_keep_unknown_chunks(dp->write_pp, PNG_HANDLE_CHUNK_ALWAYS, NULL,
             0);
-#  endif /* SET_UNKNOWN_CHUNKS */
+#  endif /* HANDLE_AS_UNKNOWN */
 
 #  ifdef PNG_SET_USER_LIMITS_SUPPORTED
       /* Remove the user limits, if any */
@@ -1764,53 +2015,53 @@ write_png(struct display *dp, const char *destname)
    /* compression outputs, IDAT and zTXt/iTXt: */
    dp->tsp = dp->nsp;
    dp->nsp = dp->csp = 0;
+#  ifdef PNG_SW_COMPRESS_png_level
+      {
+         int val;
+
+         /* This sets everything, but then the following options just override
+          * the specific settings for ICC profiles and text.
+          */
+         if (getallopts(dp, "compression", &val))
+            png_set_compression(dp->write_pp, val);
+
+         if (getallopts(dp, "ICC-profile-compression", &val))
+            png_set_ICC_profile_compression(dp->write_pp, val);
+
+         if (getallopts(dp, "text-compression", &val))
+            png_set_text_compression(dp->write_pp, val);
+      }
+#  endif /* png_level support */
    if (dp->options & SEARCH)
       search_compression(dp);
    else
       set_compression(dp);
+   set_ICC_profile_compression(dp);
    set_text_compression(dp);
 
    {
       int val;
 
       /* The permitted range is 1..0x7FFFFFFF, so the cast is safe */
-      if (getopt(dp, "IDAT-size", &val))
-         png_set_compression_buffer_size(dp->write_pp,
-               (png_alloc_size_t)/*SAFE*/val);
+      if (get_option(dp, "IDAT-size", &val))
+         png_set_IDAT_size(dp->write_pp, val);
    }
 
    /* filter handling */
-#if defined(PNG_SELECT_FILTER_HEURISTICALLY_SUPPORTED) ||\
-    defined(PNG_SELECT_FILTER_METHODICALLY_SUPPORTED)
-      {
-         int val;
-
-         if (getopt(dp, "select", &val))
-         {
-#           ifdef PNG_SELECT_FILTER_HEURISTICALLY_SUPPORTED
-               png_set_option(dp->write_pp, PNG_SELECT_FILTER_HEURISTICALLY,
-                     (val & SELECT_HEURISTICALLY) != 0);
-#           endif /* SELECT_FILTER_HEURISTICALLY */
-#           ifdef PNG_SELECT_FILTER_METHODICALLY_SUPPORTED
-               png_set_option(dp->write_pp, PNG_SELECT_FILTER_METHODICALLY,
-                     (val & SELECT_METHODICALLY) != 0);
-#           endif /* SELECT_FILTER_METHODICALLY */
-         }
-      }
-#endif /* SELECT_FILTER_HEURISTICALLY || SELECT_FILTER_METHODICALLY */
-
 #  ifdef PNG_WRITE_FILTER_SUPPORTED
       {
          int val;
 
-         if (getopt(dp, "filter", &val))
+         if (get_option(dp, "filter", &val))
             png_set_filter(dp->write_pp, PNG_FILTER_TYPE_BASE, val);
       }
 #  endif /* WRITE_FILTER */
 
    /* This just uses the 'read' info_struct directly, it contains the image. */
    dp->write_size = 0U;
+   start_timer(dp, PNGCP_TIME_WRITE);
    png_write_png(dp->write_pp, dp->ip, 0U/*transforms*/, NULL/*params*/);
+   end_timer(dp, PNGCP_TIME_WRITE);
 
    /* Make sure the file was written ok: */
    if (dp->fp != NULL)
@@ -1938,7 +2189,7 @@ cp_one_file(struct display *dp, const char *filename, const char *destname)
    {
       int val;
 
-      if (getopt(dp, "log-depth", &val) && val >= 0)
+      if (get_option(dp, "log-depth", &val) && val >= 0)
          log_depth = (unsigned int)/*SAFE*/val;
 
       else
@@ -1968,7 +2219,6 @@ cp_one_file(struct display *dp, const char *filename, const char *destname)
    /* Initialize the 'best' fields: */
    strcpy(dp->best, dp->curr);
    dp->best_size = dp->write_size;
-   log_search(dp, log_depth);
 
    if (dp->nsp > 0) /* interating over lists */
    {
@@ -1976,6 +2226,7 @@ cp_one_file(struct display *dp, const char *filename, const char *destname)
       assert(dp->curr[0] == ' ' && dp->tsp > 0);
 
       /* Cancel warnings on subsequent writes */
+      log_search(dp, log_depth);
       dp->no_warnings = 1;
 
       /* Make a temporary name for the subsequent tests: */
@@ -2069,7 +2320,7 @@ main(const int argc, const char * const * const argv)
    /* Do a quick check on the directory target case; when there are more than
     * two arguments the last one must be a directory.
     */
-   if (option_end+2 < argc && !checkdir(argv[argc-1]))
+   if (!(d.options & NOWRITE) && option_end+2 < argc && !checkdir(argv[argc-1]))
    {
       fprintf(stderr,
             "pngcp: %s: directory required with more than two arguments\n",
@@ -2093,7 +2344,7 @@ main(const int argc, const char * const * const argv)
          if (i < argc)
          {
             infile = argv[i++];
-            if (i < argc)
+            if (!(d.options & NOWRITE) && i < argc)
                outfile = argv[argc-1];
          }
 
@@ -2146,6 +2397,15 @@ main(const int argc, const char * const * const argv)
                if (infile != NULL)
                   printf(" %s", infile);
 
+#              ifdef PNG_PNGCP_TIMING_SUPPORTED
+                  /* When logging output the files for each file, if enabled. */
+                  if ((d.value[OPTIND(&d,time)] & PNGCP_TIME_READ) != 0)
+                     print_time(" read", d.read_time);
+
+                  if ((d.value[OPTIND(&d,time)] & PNGCP_TIME_WRITE) != 0)
+                     print_time(" write", d.write_time);
+#              endif /* PNGCP_TIMING */
+
                printf("\n");
                fflush(stdout);
             }
@@ -2153,8 +2413,8 @@ main(const int argc, const char * const * const argv)
 
          display_clean(&d);
       }
-      while (i+1 < argc);
-         /* I.e. for all cases after the first time through the loop require
+      while (i+!(d.options & NOWRITE) < argc);
+         /* I.e. for write cases after the first time through the loop require
           * there to be at least two arguments left and for the last one to be a
           * directory (this was checked above).
           */
@@ -2162,6 +2422,24 @@ main(const int argc, const char * const * const argv)
       /* Release allocated memory */
       display_destroy(&d);
 
+#     ifdef PNG_PNGCP_TIMING_SUPPORTED
+         {
+            int output = 0;
+
+            if ((d.value[OPTIND(&d,time)] & PNGCP_TIME_READ) != 0)
+               print_time("read", d.read_time_total), output = 1;
+
+            if ((d.value[OPTIND(&d,time)] & PNGCP_TIME_WRITE) != 0)
+            {
+               if (output) putchar(' ');
+               print_time("write", d.write_time_total);
+               output = 1;
+            }
+
+            if (output) putchar('\n');
+         }
+#     endif /* PNGCP_TIMING */
+
       return errors != 0;
    }
 }
@@ -2172,4 +2450,4 @@ main(void)
    fprintf(stderr, "pngcp: no support for png_read/write_image\n");
    return 77;
 }
-#endif
+#endif /* !READ_PNG || !WRITE_PNG */

contrib/tools/pngfix.c

@@ -2,7 +2,7 @@
  *
  * Copyright (c) 2014-2016 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.21 [January 15, 2016]
+ * Last changed in libpng 1.6.26 [October 20, 2016]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -1824,7 +1824,7 @@ IDAT_init(struct IDAT * const idat, struct file * const file)
 }
 
 static png_uint_32
-rechunk_length(struct IDAT *idat)
+rechunk_length(struct IDAT *idat, int start)
    /* Return the length for the next IDAT chunk, taking into account
     * rechunking.
     */
@@ -1836,7 +1836,7 @@ rechunk_length(struct IDAT *idat)
       const struct IDAT_list *cur;
       unsigned int count;
 
-      if (idat->idat_index == 0) /* at the new chunk (first time) */
+      if (start)
          return idat->idat_length; /* use the cache */
 
       /* Otherwise rechunk_length is called at the end of a chunk for the length
@@ -1995,7 +1995,7 @@ process_IDAT(struct file *file)
       idat->idat_index = 0; /* Index into chunk data */
 
       /* Update the chunk length to the correct value for the IDAT chunk: */
-      file->chunk->chunk_length = rechunk_length(idat);
+      file->chunk->chunk_length = rechunk_length(idat, 1/*start*/);
 
       /* Change the state to writing IDAT chunks */
       file->state = STATE_IDAT;
@@ -3473,7 +3473,8 @@ read_callback(png_structp png_ptr, png_bytep buffer, size_t count)
                      /* Write another IDAT chunk.  Call rechunk_length to
                       * calculate the length required.
                       */
-                     length = chunk->chunk_length = rechunk_length(file->idat);
+                     length = chunk->chunk_length =
+                         rechunk_length(file->idat, 0/*end*/);
                      assert(type == png_IDAT);
                      file->write_count = 0; /* for the new chunk */
                      --(file->write_count); /* fake out the increment below */

contrib/tools/reindent

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+# reindent a libpng C source
+
+# COPYRIGHT: Written by Glenn Randers-Pehrson, 2016.
+# To the extent possible under law, the author has waived all copyright and
+# related or neighboring rights to this work.  This work is published from:
+# United States.
+
+# Usage:
+# reindent inputtabsize outputtabsize inputcontinuestring outputcontinuestring
+#
+# Assumes that continued lines begin with indentation plus one space, and
+# that continued comments begin with indentation plus " *".
+#
+# eg, to change libpng coding style from 3-space indentation with 4-space
+# continuations to 4-space indentation with 2-space continuations:
+#
+#  reindent 3 4 "\t " "  " < example.c > example.c_4_2
+# and to restore the file back to libpng coding style
+#  reindent 4 3 "  " "    " < example.c_4_2 > example.c_3_4
+
+unexpand --first-only --t $1 | \
+   sed -e "/^	*$3[^\*]/{s/$3/$4/}" | \
+   expand -t $2

contrib/tools/sRGB.h

@@ -14,7 +14,7 @@
  * All routines take and return a floating point value in the range
  * 0 to 1.0, doing a calculation according to the sRGB specification
  * (in fact the source of the numbers is the wikipedia article at
- * http://en.wikipedia.org/wiki/SRGB).
+ * https://en.wikipedia.org/wiki/SRGB).
  */
 static double
 sRGB_from_linear(double l)

example.c

@@ -97,7 +97,7 @@ int main(int argc, const char **argv)
           */
          if (buffer != NULL &&
             png_image_finish_read(&image, NULL/*background*/, buffer,
-               0/*row_stride*/, NULL/*colormap*/) != 0)
+                0/*row_stride*/, NULL/*colormap*/) != 0)
          {
             /* Now write the image out to the second argument.  In the write
              * call 'convert_to_8bit' allows 16-bit data to be squashed down to
@@ -105,7 +105,7 @@ int main(int argc, const char **argv)
              * to the 8-bit format.
              */
             if (png_image_write_to_file(&image, argv[2], 0/*convert_to_8bit*/,
-               buffer, 0/*row_stride*/, NULL/*colormap*/) != 0)
+                buffer, 0/*row_stride*/, NULL/*colormap*/) != 0)
             {
                /* The image has been written successfully. */
                exit(0);
@@ -295,7 +295,7 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
     * was compiled with a compatible version of the library.  REQUIRED
     */
    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
-      png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+       png_voidp user_error_ptr, user_error_fn, user_warning_fn);
 
    if (png_ptr == NULL)
    {
@@ -375,7 +375,7 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
     * low byte.
     */
 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
-    png_set_scale_16(png_ptr);
+   png_set_scale_16(png_ptr);
 #else
    png_set_strip_16(png_ptr);
 #endif
@@ -419,10 +419,10 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
 
    if (png_get_bKGD(png_ptr, info_ptr, &image_background) != 0)
       png_set_background(png_ptr, image_background,
-                         PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+          PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
    else
       png_set_background(png_ptr, &my_background,
-                         PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+          PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
 
    /* Some suggestions as to how to get a screen gamma value
     *
@@ -481,7 +481,7 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
          png_color std_color_cube[MAX_SCREEN_COLORS];
 
          png_set_quantize(png_ptr, std_color_cube, MAX_SCREEN_COLORS,
-            MAX_SCREEN_COLORS, NULL, 0);
+             MAX_SCREEN_COLORS, NULL, 0);
       }
       /* This reduces the image to the palette supplied in the file */
       else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette) != 0)
@@ -491,7 +491,7 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
          png_get_hIST(png_ptr, info_ptr, &histogram);
 
          png_set_quantize(png_ptr, palette, num_palette,
-                        max_screen_colors, histogram, 0);
+             max_screen_colors, histogram, 0);
       }
    }
 #endif /* READ_QUANTIZE */
@@ -522,7 +522,7 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
    png_set_swap(png_ptr);
 
    /* Add filler (or alpha) byte (before/after each RGB triplet) */
-   png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
+   png_set_filler(png_ptr, 0xffff, PNG_FILLER_AFTER);
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Turn on interlace handling.  REQUIRED if you are not using
@@ -532,7 +532,7 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
    number_passes = png_set_interlace_handling(png_ptr);
 #else /* !READ_INTERLACING */
    number_passes = 1;
-#endif /* !READ_INTERLACING */
+#endif /* READ_INTERLACING */
 
 
    /* Optional call to gamma correct and add the background to the palette
@@ -552,7 +552,7 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
 
    for (row = 0; row < height; row++)
       row_pointers[row] = png_malloc(png_ptr, png_get_rowbytes(png_ptr,
-         info_ptr));
+          info_ptr));
 
    /* Now it's time to read the image.  One of these methods is REQUIRED */
 #ifdef entire /* Read the entire image in one go */
@@ -574,10 +574,10 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
       {
 #ifdef sparkle /* Read the image using the "sparkle" effect. */
          png_read_rows(png_ptr, &row_pointers[y], NULL,
-            number_of_rows);
+             number_of_rows);
 #else no_sparkle /* Read the image using the "rectangle" effect */
          png_read_rows(png_ptr, NULL, &row_pointers[y],
-            number_of_rows);
+             number_of_rows);
 #endif no_sparkle /* Use only one of these two methods */
       }
 
@@ -614,7 +614,7 @@ initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
     * linked libraries.
     */
    *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
-       png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+        png_voidp user_error_ptr, user_error_fn, user_warning_fn);
 
    if (*png_ptr == NULL)
    {
@@ -649,14 +649,14 @@ initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
     * the function png_get_progressive_ptr(png_ptr).
     */
    png_set_progressive_read_fn(*png_ptr, (void *)stream_data,
-      info_callback, row_callback, end_callback);
+       info_callback, row_callback, end_callback);
 
    return (OK);
 }
 
 int
 process_data(png_structp *png_ptr, png_infop *info_ptr,
-   png_bytep buffer, png_uint_32 length)
+    png_bytep buffer, png_uint_32 length)
 {
    if (setjmp(png_jmpbuf((*png_ptr))))
    {
@@ -691,7 +691,7 @@ info_callback(png_structp png_ptr, png_infop info)
 }
 
 row_callback(png_structp png_ptr, png_bytep new_row,
-   png_uint_32 row_num, int pass)
+    png_uint_32 row_num, int pass)
 {
    /*
     * This function is called for every row in the image.  If the
@@ -780,7 +780,7 @@ void write_png(char *file_name /* , ... other image information ... */)
     * in case we are using dynamically linked libraries.  REQUIRED.
     */
    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
-      png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+       png_voidp user_error_ptr, user_error_fn, user_warning_fn);
 
    if (png_ptr == NULL)
    {
@@ -819,7 +819,7 @@ void write_png(char *file_name /* , ... other image information ... */)
     * png_init_io() here you would call
     */
    png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn,
-      user_IO_flush_function);
+       user_IO_flush_function);
    /* where user_io_ptr is a structure you want available to the callbacks */
 #endif no_streams /* Only use one initialization method */
 
@@ -842,7 +842,7 @@ void write_png(char *file_name /* , ... other image information ... */)
     * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
     */
    png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, PNG_COLOR_TYPE_???,
-      PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+       PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
    /* Set the palette if there is one.  REQUIRED for indexed-color images */
    palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
@@ -988,11 +988,11 @@ void write_png(char *file_name /* , ... other image information ... */)
    png_bytep row_pointers[height];
 
    if (height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
-     png_error (png_ptr, "Image is too tall to process in memory");
+      png_error (png_ptr, "Image is too tall to process in memory");
 
    /* Set up pointers into your "image" byte array */
    for (k = 0; k < height; k++)
-     row_pointers[k] = image + k*width*bytes_per_pixel;
+      row_pointers[k] = image + k*width*bytes_per_pixel;
 
    /* One of the following output methods is REQUIRED */
 

libpng-manual.txt

@@ -1,9 +1,9 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.7.0beta80 - May 6, 2016
+ libpng version 1.7.0beta90 - August 28, 2017
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
- Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ Copyright (c) 1998-2017 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
  For conditions of distribution and use, see the disclaimer
@@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.7.0beta80 - May 6, 2016
+ libpng versions 0.97, January 1998, through 1.7.0beta90 - August 28, 2017
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
@@ -67,17 +67,17 @@ file format in application programs.
 
 The PNG specification (second edition), November 2003, is available as
 a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at
-<http://www.w3.org/TR/2003/REC-PNG-20031110/
+<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
-<http://png-mng.sourceforge.net/pub/png/spec/1.2/>.
+<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.
 
-The PNG-1.0 specification is available as RFC 2083 
-<http://png-mng.sourceforge.net/pub/png/spec/1.0/> and as a
-W3C Recommendation <http://www.w3.org/TR/REC-png-961001>.
+The PNG-1.0 specification is available as RFC 2083
+<https://png-mng.sourceforge.io/pub/png/spec/1.0/> and as a
+W3C Recommendation <https://www.w3.org/TR/REC-png-961001>.
 
 Some additional chunks are described in the special-purpose public chunks
 documents at <http://www.libpng.org/pub/png/spec/register/>
@@ -102,7 +102,7 @@ majority of the needs of its users.
 
 Libpng uses zlib for its compression and decompression of PNG files.
 Further information about zlib, and the latest version of zlib, can
-be found at the zlib home page, <http://zlib.net/>.
+be found at the zlib home page, <https://zlib.net/>.
 The zlib compression utility is a general purpose utility that is
 useful for more than PNG files, and can be used without libpng.
 See the documentation delivered with zlib for more details.
@@ -471,8 +471,9 @@ the default, use
 
 The values for png_set_crc_action() say how libpng is to handle CRC errors in
 ancillary and critical chunks, and whether to use the data contained
-therein.  Note that it is impossible to "discard" data in a critical
-chunk.
+therein. Starting with libpng-1.6.26, this also governs how an ADLER32 error
+is handled while reading the IDAT chunk. Note that it is impossible to
+"discard" data in a critical chunk.
 
 Choices for (int) crit_action are
    PNG_CRC_DEFAULT      0  error/quit
@@ -489,6 +490,9 @@ Choices for (int) ancil_action are
    PNG_CRC_QUIET_USE    4  quiet/use data
    PNG_CRC_NO_CHANGE    5  use the current value
 
+When the setting for crit_action is PNG_CRC_QUIET_USE, the CRC and ADLER32
+checksums are not only ignored, but they are not evaluated.
+
 Setting up callback code
 
 You can set up a callback function to handle any unknown chunks in the
@@ -563,7 +567,7 @@ non-interlaced case the row that was just handled is simply one less than the
 passed in row number, and pass will always be 0.  For the interlaced case the
 same applies unless the row value is 0, in which case the row just handled was
 the last one from one of the preceding passes.  Because interlacing may skip a
-pass you cannot be sure that the preceding pass is just 'pass-1', if you really
+pass you cannot be sure that the preceding pass is just 'pass-1'; if you really
 need to know what the last pass is record (row,pass) from the callback and use
 the last recorded value each time.
 
@@ -3833,7 +3837,7 @@ The #defines to be used in png_image::format.  Each #define identifies a
 particular layout of channel data and, if present, alpha values.  There are
 separate defines for each of the two channel encodings.
 
-A format is built up using single bit flag values.  Not all combinations are
+A format is built up using one-bit flag values.  Not all combinations are
 valid: use the bit flag values below for testing a format returned by the
 read APIs, but set formats from the derived values.
 
@@ -4046,7 +4050,7 @@ READ APIs
 
 When the simplified API needs to convert between sRGB and linear colorspaces,
 the actual sRGB transfer curve defined in the sRGB specification (see the
-article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
+article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
 approximation used elsewhere in libpng.
 
 WRITE APIS
@@ -4223,7 +4227,7 @@ However, there are some uncertainties about the status of local variables
 after a longjmp, so the user may want to be careful about doing anything
 after setjmp returns non-zero besides returning itself.  Consult your
 compiler documentation for more details.  For an alternative approach, you
-may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net),
+may wish to use the "cexcept" facility (see https://cexcept.sourceforge.io/),
 which is illustrated in pngvalid.c and in contrib/visupng.
 
 Beginning in libpng-1.4.0, the png_set_benign_errors() API became available.
@@ -4443,7 +4447,7 @@ in a MNG datastream.  As a minimum, it must have the MNG 8-byte signature
 and the MHDR and MEND chunks.  Libpng does not provide support for these
 or any other MNG chunks; your application must provide its own support for
 them.  You may wish to consider using libmng (available at
-http://www.libmng.com) instead.
+https://www.libmng.com/) instead.
 
 VIII.  Changes to Libpng from version 0.88
 
@@ -5185,27 +5189,33 @@ control.  The git repository was built from old libpng-x.y.z.tar.gz files
 going back to version 0.70.  You can access the git repository (read only)
 at
 
-    git://git.code.sf.net/p/libpng/code
+    https://github.com/glennrp/libpng or
+    https://git.code.sf.net/p/libpng/code.git
 
-or you can browse it with a web browser by selecting the "code" button at
+or you can browse it with a web browser at
 
-    https://sourceforge.net/projects/libpng
+    https://github.com/glennrp/libpng or
+    https://sourceforge.net/p/libpng/code/ci/libpng16/tree/
 
 Patches can be sent to glennrp at users.sourceforge.net or to
 png-mng-implement at lists.sourceforge.net or you can upload them to
 the libpng bug tracker at
 
-    http://libpng.sourceforge.net
+    https://libpng.sourceforge.io/
+
+or as a "pull request" to
+
+    https://github.com/glennrp/libpng/pulls
 
 We also accept patches built from the tar or zip distributions, and
 simple verbal discriptions of bug fixes, reported either to the
 SourceForge bug tracker, to the png-mng-implement at lists.sf.net
-mailing list, or directly to glennrp.
+mailing list, as github issues, or directly to glennrp.
 
 XVI. Coding style
 
 Our coding style is similar to the "Allman" style
-(See http://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
+(See https://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
 braces on separate lines:
 
     if (condition)
@@ -5247,6 +5257,19 @@ the statement that follows the comment:
      */
     statement;
 
+%17+%Linus Torvalds recomends putting the leading "/*" in multiple-line
+%17+%comments on a separate line:
+%17+%
+%17+%    /*
+%17+%     * This is a multiple-line
+%17+%     * comment.
+%17+%     */
+%17+%    statement;
+%17+%
+%17+%See
+%17+%https://developers.slashdot.org/story/16/07/12/2036201
+%17+%/linus-torvalds-in-sweary-rant-about-punctuation-in-kernel-comments
+%17+%
 Very short comments can be placed after the end of the statement
 to which they pertain:
 
@@ -5306,7 +5329,7 @@ Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as
 though it were a function.
 
 Control keywords if, for, while, and switch are always followed by a space
-to distinguish them from function calls, which have no trailing space. 
+to distinguish them from function calls, which have no trailing space.
 
 We put a space after each comma and after each semicolon
 in "for" statements, and we put spaces before and after each
@@ -5328,8 +5351,9 @@ with an even number of lower-case hex digits (e.g., 0x00, 0xff, 0x0100).
 We prefer to use underscores in variable names rather than camelCase, except
 for a few type names that we inherit from zlib.h.
 
-We prefer "if (something != 0)" and "if (something == 0)"
-over "if (something)" and if "(!something)", respectively.
+We prefer "if (something != 0)" and "if (something == 0)" over
+"if (something)" and if "(!something)", respectively, and for pointers
+we prefer "if (some_pointer != NULL)" or "if (some_pointer == NULL)".
 
 We do not use the TAB character for indentation in the C sources.
 
@@ -5343,7 +5367,7 @@ Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.7.0beta80 are Y2K compliant.  It is my belief that earlier
+upward through 1.7.0beta90 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has two year fields.  One is a 2-byte unsigned integer

libpng.3

@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "May 6, 2016"
+.TH LIBPNG 3 "August 28, 2017"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta80
+libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta90
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@@ -500,10 +500,10 @@ 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
 
- libpng version 1.7.0beta80 - May 6, 2016
+ libpng version 1.7.0beta90 - August 28, 2017
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
- Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ Copyright (c) 1998-2017 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
  For conditions of distribution and use, see the disclaimer
@@ -511,7 +511,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.7.0beta80 - May 6, 2016
+ libpng versions 0.97, January 1998, through 1.7.0beta90 - August 28, 2017
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
@@ -567,17 +567,17 @@ file format in application programs.
 
 The PNG specification (second edition), November 2003, is available as
 a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at
-<http://www.w3.org/TR/2003/REC-PNG-20031110/
+<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
-<http://png-mng.sourceforge.net/pub/png/spec/1.2/>.
+<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.
 
-The PNG-1.0 specification is available as RFC 2083 
-<http://png-mng.sourceforge.net/pub/png/spec/1.0/> and as a
-W3C Recommendation <http://www.w3.org/TR/REC-png-961001>.
+The PNG-1.0 specification is available as RFC 2083
+<https://png-mng.sourceforge.io/pub/png/spec/1.0/> and as a
+W3C Recommendation <https://www.w3.org/TR/REC-png-961001>.
 
 Some additional chunks are described in the special-purpose public chunks
 documents at <http://www.libpng.org/pub/png/spec/register/>
@@ -602,7 +602,7 @@ majority of the needs of its users.
 
 Libpng uses zlib for its compression and decompression of PNG files.
 Further information about zlib, and the latest version of zlib, can
-be found at the zlib home page, <http://zlib.net/>.
+be found at the zlib home page, <https://zlib.net/>.
 The zlib compression utility is a general purpose utility that is
 useful for more than PNG files, and can be used without libpng.
 See the documentation delivered with zlib for more details.
@@ -971,8 +971,9 @@ the default, use
 
 The values for png_set_crc_action() say how libpng is to handle CRC errors in
 ancillary and critical chunks, and whether to use the data contained
-therein.  Note that it is impossible to "discard" data in a critical
-chunk.
+therein. Starting with libpng-1.6.26, this also governs how an ADLER32 error
+is handled while reading the IDAT chunk. Note that it is impossible to
+"discard" data in a critical chunk.
 
 Choices for (int) crit_action are
    PNG_CRC_DEFAULT      0  error/quit
@@ -989,6 +990,9 @@ Choices for (int) ancil_action are
    PNG_CRC_QUIET_USE    4  quiet/use data
    PNG_CRC_NO_CHANGE    5  use the current value
 
+When the setting for crit_action is PNG_CRC_QUIET_USE, the CRC and ADLER32
+checksums are not only ignored, but they are not evaluated.
+
 .SS Setting up callback code
 
 You can set up a callback function to handle any unknown chunks in the
@@ -1063,7 +1067,7 @@ non-interlaced case the row that was just handled is simply one less than the
 passed in row number, and pass will always be 0.  For the interlaced case the
 same applies unless the row value is 0, in which case the row just handled was
 the last one from one of the preceding passes.  Because interlacing may skip a
-pass you cannot be sure that the preceding pass is just 'pass\-1', if you really
+pass you cannot be sure that the preceding pass is just 'pass\-1'; if you really
 need to know what the last pass is record (row,pass) from the callback and use
 the last recorded value each time.
 
@@ -4333,7 +4337,7 @@ The #defines to be used in png_image::format.  Each #define identifies a
 particular layout of channel data and, if present, alpha values.  There are
 separate defines for each of the two channel encodings.
 
-A format is built up using single bit flag values.  Not all combinations are
+A format is built up using one-bit flag values.  Not all combinations are
 valid: use the bit flag values below for testing a format returned by the
 read APIs, but set formats from the derived values.
 
@@ -4546,7 +4550,7 @@ READ APIs
 
 When the simplified API needs to convert between sRGB and linear colorspaces,
 the actual sRGB transfer curve defined in the sRGB specification (see the
-article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
+article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
 approximation used elsewhere in libpng.
 
 WRITE APIS
@@ -4723,7 +4727,7 @@ However, there are some uncertainties about the status of local variables
 after a longjmp, so the user may want to be careful about doing anything
 after setjmp returns non-zero besides returning itself.  Consult your
 compiler documentation for more details.  For an alternative approach, you
-may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net),
+may wish to use the "cexcept" facility (see https://cexcept.sourceforge.io/),
 which is illustrated in pngvalid.c and in contrib/visupng.
 
 Beginning in libpng-1.4.0, the png_set_benign_errors() API became available.
@@ -4943,7 +4947,7 @@ in a MNG datastream.  As a minimum, it must have the MNG 8-byte signature
 and the MHDR and MEND chunks.  Libpng does not provide support for these
 or any other MNG chunks; your application must provide its own support for
 them.  You may wish to consider using libmng (available at
-http://www.libmng.com) instead.
+https://www.libmng.com/) instead.
 
 .SH VIII.  Changes to Libpng from version 0.88
 
@@ -5685,27 +5689,33 @@ control.  The git repository was built from old libpng-x.y.z.tar.gz files
 going back to version 0.70.  You can access the git repository (read only)
 at
 
-    git://git.code.sf.net/p/libpng/code
+    https://github.com/glennrp/libpng or
+    https://git.code.sf.net/p/libpng/code.git
 
-or you can browse it with a web browser by selecting the "code" button at
+or you can browse it with a web browser at
 
-    https://sourceforge.net/projects/libpng
+    https://github.com/glennrp/libpng or
+    https://sourceforge.net/p/libpng/code/ci/libpng16/tree/
 
 Patches can be sent to glennrp at users.sourceforge.net or to
 png-mng-implement at lists.sourceforge.net or you can upload them to
 the libpng bug tracker at
 
-    http://libpng.sourceforge.net
+    https://libpng.sourceforge.io/
+
+or as a "pull request" to
+
+    https://github.com/glennrp/libpng/pulls
 
 We also accept patches built from the tar or zip distributions, and
 simple verbal discriptions of bug fixes, reported either to the
 SourceForge bug tracker, to the png-mng-implement at lists.sf.net
-mailing list, or directly to glennrp.
+mailing list, as github issues, or directly to glennrp.
 
 .SH XVI. Coding style
 
 Our coding style is similar to the "Allman" style
-(See http://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
+(See https://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
 braces on separate lines:
 
     if (condition)
@@ -5747,6 +5757,19 @@ the statement that follows the comment:
      */
     statement;
 
+%17+%Linus Torvalds recomends putting the leading "/*" in multiple-line
+%17+%comments on a separate line:
+%17+%
+%17+%    /*
+%17+%     * This is a multiple-line
+%17+%     * comment.
+%17+%     */
+%17+%    statement;
+%17+%
+%17+%See
+%17+%https://developers.slashdot.org/story/16/07/12/2036201
+%17+%/linus-torvalds-in-sweary-rant-about-punctuation-in-kernel-comments
+%17+%
 Very short comments can be placed after the end of the statement
 to which they pertain:
 
@@ -5806,7 +5829,7 @@ Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as
 though it were a function.
 
 Control keywords if, for, while, and switch are always followed by a space
-to distinguish them from function calls, which have no trailing space. 
+to distinguish them from function calls, which have no trailing space.
 
 We put a space after each comma and after each semicolon
 in "for" statements, and we put spaces before and after each
@@ -5828,8 +5851,9 @@ with an even number of lower-case hex digits (e.g., 0x00, 0xff, 0x0100).
 We prefer to use underscores in variable names rather than camelCase, except
 for a few type names that we inherit from zlib.h.
 
-We prefer "if (something != 0)" and "if (something == 0)"
-over "if (something)" and if "(!something)", respectively.
+We prefer "if (something != 0)" and "if (something == 0)" over
+"if (something)" and if "(!something)", respectively, and for pointers
+we prefer "if (some_pointer != NULL)" or "if (some_pointer == NULL)".
 
 We do not use the TAB character for indentation in the C sources.
 
@@ -5843,7 +5867,7 @@ Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.7.0beta80 are Y2K compliant.  It is my belief that earlier
+upward through 1.7.0beta90 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has two year fields.  One is a 2-byte unsigned integer
@@ -5940,15 +5964,13 @@ the first widely used release:
  ...
  1.0.19                  10    10019  10.so.0.19[.0]
  ...
- 1.2.53                  13    10253  12.so.0.53[.0]
+ 1.2.57                  13    10257  12.so.0.56[.0]
  ...
- 1.5.23                  15    10523  15.so.15.23[.0]
- ...
- 1.6.19beta01-04         16    10619  16.so.16.19[.0]
- 1.6.19rc01-03           16    10619  16.so.16.19[.0]
+ 1.5.28                  15    10528  15.so.15.28[.0]
  ...
+ 1.6.28                  16    10628  16.so.16.28[.0]
  1.7.0alpha01-10         17    10700  17.so.17.0[.0]
- 1.7.0beta01-80          17    10700  17.so.17.0[.0]
+ 1.7.0beta01-86          17    10700  17.so.17.0[.0]
 
 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@@ -5965,7 +5987,7 @@ release number plus "betaNN" or "rcNN".
 .LP
 .IR libpng :
 .IP
-http://libpng.sourceforge.net (follow the [DOWNLOAD] link)
+https://libpng.sourceforge.io/ (follow the [DOWNLOAD] link)
 http://www.libpng.org/pub/png
 
 .LP
@@ -5975,7 +5997,7 @@ http://www.libpng.org/pub/png
 .I libpng
 or at
 .br
-ftp://ftp.info-zip.org/pub/infozip/zlib
+https://zlib.net/
 
 .LP
 .IR PNG specification: RFC 2083
@@ -5984,11 +6006,11 @@ ftp://ftp.info-zip.org/pub/infozip/zlib
 .I libpng
 or at
 .br
-ftp://ftp.rfc-editor.org:/in-notes/rfc2083.txt
+https://www.ietf.org/rfc/rfc2083.txt
 .br
 or (as a W3C Recommendation) at
 .br
-http://www.w3.org/TR/REC-png.html
+https://www.w3.org/TR/REC-png.html
 
 .LP
 In the case of any inconsistency between the PNG specification
@@ -6004,7 +6026,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.7.0beta80 - May 6, 2016:
+Libpng version 1.7.0beta90 - August 28, 2017:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -6029,8 +6051,8 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000, through 1.7.0beta80, May 6, 2016, are
-Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
+libpng versions 1.0.7, July 1, 2000 through 1.7.0beta90, August 28, 2017 are
+Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
 added to the list of Contributing Authors:
@@ -6051,6 +6073,10 @@ and with the following additions to the disclaimer:
    risk of satisfactory quality, performance, accuracy, and effort is with
    the user.
 
+Some files in the "contrib" directory and some configure-generated
+files that are distributed with libpng have other copyright owners and
+are released under other open source licenses.
+
 libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
 Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
 libpng-0.96, and are distributed according to the same disclaimer and
@@ -6074,6 +6100,9 @@ Contributing Authors:
    Greg Roelofs
    Tom Tanner
 
+Some files in the "scripts" directory have other copyright owners
+but are released under this license.
+
 libpng versions 0.5, May 1995, through 0.88, January 1996, are
 Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 
@@ -6114,6 +6143,29 @@ appreciated.
 
 END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
 
+TRADEMARK:
+
+The name "libpng" has not been registered by the Copyright owner
+as a trademark in any jurisdiction.  However, because libpng has
+been distributed and maintained world-wide, continually since 1995,
+the Copyright owner claims "common-law trademark protection" in any
+jurisdiction where common-law trademark is recognized.
+
+OSI CERTIFICATION:
+
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
+a certification mark of the Open Source Initiative. OSI has not addressed
+the additional disclaimers inserted at version 1.0.7.
+
+EXPORT CONTROL:
+
+The Copyright owner believes that the Export Control Classification
+Number (ECCN) for libpng is EAR99, which means not subject to export
+controls or International Traffic in Arms Regulations (ITAR) because
+it is open source, publicly available software, that does not contain
+any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
+734.7(b).
+
 A "png_get_copyright" function is available, for convenient use in "about"
 boxes and the like:
 
@@ -6122,13 +6174,9 @@ boxes and the like:
 Also, the PNG logo (in PNG format, of course) is supplied in the
 files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
 
-Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
-a certification mark of the Open Source Initiative. OSI has not addressed
-the additional disclaimers inserted at version 1.0.7.
-
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-May 6, 2016
+August 28, 2017
 
 .\" end of man page
 

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "May 6, 2016"
+.TH LIBPNGPF 3 "August 28, 2017"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta80
+libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta90
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "May 6, 2016"
+.TH PNG 5 "August 28, 2017"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
@@ -23,12 +23,12 @@ platforms.
 PNG specification (second edition), November 2003:
 .IP
 .br
-  <http://www.w3.org/TR/2003/REC-PNG-20031110/
+  <https://www.w3.org/TR/2003/REC-PNG-20031110/
 .LP
 PNG 1.2 specification, July 1999:
 .IP
 .br
-http://png-mng.sourceforge.net/pub/png/spec/1.2/
+https://png-mng.sourceforge.io/pub/png/spec/1.2/
 .LP
 PNG 1.0 specification, October 1996:
 .IP
@@ -36,11 +36,11 @@ PNG 1.0 specification, October 1996:
 RFC 2083
 .IP
 .br
-ftp://ds.internic.net/rfc/rfc2083.txt
+https://www.ietf.org/rfc/rfc2083.txt
 .br
 or (as a W3C Recommendation) at
 .br
-http://www.w3.org/TR/REC-png-961001
+https://www.w3.org/TR/REC-png-961001
 .SH AUTHORS
 This man page: Glenn Randers-Pehrson
 .LP

png.c

@@ -2,7 +2,7 @@
 /* png.c - location for general purpose libpng functions
  *
  * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -15,7 +15,7 @@
 #define PNG_SRC_FILE PNG_SRC_FILE_png
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_7_0beta80 Your_png_h_is_not_version_1_7_0beta80;
+typedef png_libpng_version_1_7_0beta90 Your_png_h_is_not_version_1_7_0beta90;
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
@@ -81,7 +81,7 @@ png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED)
    if (items >= (~(png_alloc_size_t)0)/size)
    {
       png_warning(png_voidcast(png_structrp, png_ptr),
-         "Potential overflow in png_zalloc()");
+          "Potential overflow in png_zalloc()");
       return NULL;
    }
 
@@ -100,10 +100,26 @@ png_zfree(voidpf png_ptr, voidpf ptr)
  * in case CRC is > 32 bits to leave the top bits 0.
  */
 void /* PRIVATE */
-png_reset_crc(png_structrp png_ptr)
+png_reset_crc(png_structrp png_ptr, png_const_bytep chunk_tag)
 {
-   /* The cast is safe because the crc is a 32 bit value. */
-   png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0);
+#  ifdef PNG_READ_SUPPORTED
+      if (png_ptr->read_struct)
+      {
+         /* Set png_struct::current_crc appropriately. */
+         if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))
+            png_ptr->current_crc = png_ptr->ancillary_crc;
+
+         else /* critical */
+            png_ptr->current_crc = png_ptr->critical_crc;
+      }
+
+      else
+         png_ptr->current_crc = crc_error_quit; /* for write */
+
+      /* Now do not calculate the CRC if it isn't required: */
+      if (png_ptr->current_crc != crc_quiet_use)
+#  endif /* READ */
+   png_ptr->crc = 0xFFFFFFFFU & crc32(0, chunk_tag, 4);
 }
 
 /* Calculate the CRC over a section of data.  We can only pass as
@@ -114,27 +130,15 @@ png_reset_crc(png_structrp png_ptr)
 void /* PRIVATE */
 png_calculate_crc(png_structrp png_ptr, png_const_voidp ptr, png_size_t length)
 {
-   int need_crc = 1;
-
-   if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0)
-   {
-      if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
-          (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
-         need_crc = 0;
-   }
-
-   else /* critical */
-   {
-      if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
-         need_crc = 0;
-   }
-
    /* 'uLong' is defined in zlib.h as unsigned long; this means that on some
     * systems it is a 64 bit value.  crc32, however, returns 32 bits so the
     * following cast is safe.  'uInt' may be no more than 16 bits, so it is
     * necessary to perform a loop here.
     */
-   if (need_crc != 0 && length > 0)
+#  ifdef PNG_READ_SUPPORTED
+      if (png_ptr->current_crc != crc_quiet_use)
+#  endif /* READ */
+   if (length > 0)
    {
       uLong crc = png_ptr->crc; /* Should never issue a warning */
       const Bytef* rptr = png_voidcast(const Bytef*,ptr);
@@ -171,58 +175,53 @@ png_calculate_crc(png_structrp png_ptr, png_const_voidp ptr, png_size_t length)
 /* Check a user supplied version number, called from both read and write
  * functions that create a png_struct.
  */
-int
+static int
 png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
 {
-     /* Libpng versions 1.0.0 and later are binary compatible if the version
-      * string matches through the second '.'; we must recompile any
-      * applications that use any older library version.
-      */
-
+   /* Libpng versions 1.0.0 and later are binary compatible if the version
+    * string matches through the second '.'; we must recompile any applications
+    * that use any older library version.
+    */
    if (user_png_ver != NULL)
    {
+      int library_match = 1;
       int i = -1;
-      int found_dots = 0;
+      unsigned int found_dots = 0;
 
       do
       {
          i++;
          if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i])
-            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+            library_match = 0;
          if (user_png_ver[i] == '.')
             found_dots++;
-      } while (found_dots < 2 && user_png_ver[i] != 0 &&
+      } while (library_match && found_dots < 2 && user_png_ver[i] != 0 &&
             PNG_LIBPNG_VER_STRING[i] != 0);
+
+      if (library_match)
+         return 1; /* Library matches ok */
    }
 
-   else
-      png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-
-   if ((png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) != 0)
-   {
+   /* Failure: mismatched library major version number */
 #ifdef PNG_WARNINGS_SUPPORTED
+   {
       size_t pos = 0;
       char m[128];
 
       pos = png_safecat(m, (sizeof m), pos,
           "Application built with libpng-");
+      /* This is ok if user_png_ver is NULL, it appends nothing: */
       pos = png_safecat(m, (sizeof m), pos, user_png_ver);
       pos = png_safecat(m, (sizeof m), pos, " but running with ");
       pos = png_safecat(m, (sizeof m), pos, PNG_LIBPNG_VER_STRING);
       PNG_UNUSED(pos)
 
-      png_warning(png_ptr, m);
-#endif
-
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-      png_ptr->flags = 0;
-#endif
-
-      return 0;
+      png_app_warning(png_ptr, m);
    }
+#endif
 
-   /* Success return. */
-   return 1;
+   return 0; /* Failure */
+   PNG_UNUSED(png_ptr) /* if no warning */
 }
 
 /* Generic function to create a png_struct for either read or write - this
@@ -311,7 +310,7 @@ png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
          if (png_user_version_check(&create_struct, user_png_ver) != 0)
          {
             png_structrp png_ptr = png_voidcast(png_structrp,
-               png_malloc_warn(&create_struct, (sizeof *png_ptr)));
+                png_malloc_warn(&create_struct, (sizeof *png_ptr)));
 
             if (png_ptr != NULL)
             {
@@ -353,7 +352,7 @@ png_create_info_struct,(png_const_structrp png_ptr),PNG_ALLOCATED)
     * has always been done in 'example.c'.
     */
    info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr,
-      (sizeof *info_ptr)));
+       (sizeof *info_ptr)));
 
    if (info_ptr != NULL)
       memset(info_ptr, 0, (sizeof *info_ptr));
@@ -400,7 +399,7 @@ png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr)
 
 void PNGAPI
 png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask,
-   int num)
+    int num)
 {
    png_debug(1, "in png_free_data");
 
@@ -428,6 +427,7 @@ png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask,
          png_free(png_ptr, info_ptr->text);
          info_ptr->text = NULL;
          info_ptr->num_text = 0;
+         info_ptr->max_text = 0;
       }
    }
 #endif
@@ -705,15 +705,15 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.7.0beta80 - May 6, 2016" PNG_STRING_NEWLINE \
-     "Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson" \
+     "libpng version 1.7.0beta90 - August 28, 2017" PNG_STRING_NEWLINE \
+     "Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson" \
      PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE;
 #  else
-      return "libpng version 1.7.0beta80 - May 6, 2016\
-      Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson\
+      return "libpng version 1.7.0beta90 - August 28, 2017\
+      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.";
 #  endif
@@ -934,7 +934,7 @@ png_zstream_error(z_stream *zstream, int ret)
 #ifdef PNG_GAMMA_SUPPORTED /* always set if COLORSPACE */
 static int
 png_colorspace_check_gamma(png_const_structrp png_ptr,
-   png_colorspacerp colorspace, png_fixed_point gAMA, int from)
+    png_colorspacerp colorspace, png_fixed_point gAMA, int from)
    /* This is called to check a new gamma value against an existing one.  The
     * routine returns false if the new gamma value should not be written.
     *
@@ -954,7 +954,7 @@ png_colorspace_check_gamma(png_const_structrp png_ptr,
    png_fixed_point gtest;
 
    if ((colorspace->flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
-      (png_muldiv(&gtest, colorspace->gamma, PNG_FP_1, gAMA) == 0  ||
+       (png_muldiv(&gtest, colorspace->gamma, PNG_FP_1, gAMA) == 0  ||
        gtest < PNG_FP_1 - 1000 || gtest > PNG_FP_1 + 1000))
    {
       /* Either this is an sRGB image, in which case the calculated gamma
@@ -966,7 +966,7 @@ png_colorspace_check_gamma(png_const_structrp png_ptr,
       if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0 || from == 2)
       {
          png_chunk_report(png_ptr, "gamma value does not match sRGB",
-            PNG_CHUNK_ERROR);
+             PNG_CHUNK_ERROR);
          /* Do not overwrite an sRGB value */
          return from == 2;
       }
@@ -974,7 +974,7 @@ png_colorspace_check_gamma(png_const_structrp png_ptr,
       else /* sRGB tag not involved */
       {
          png_chunk_report(png_ptr, "gamma value does not match libpng estimate",
-            PNG_CHUNK_WARNING);
+             PNG_CHUNK_WARNING);
          return from == 1;
       }
    }
@@ -984,7 +984,7 @@ png_colorspace_check_gamma(png_const_structrp png_ptr,
 
 void /* PRIVATE */
 png_colorspace_set_gamma(png_const_structrp png_ptr,
-   png_colorspacerp colorspace, png_fixed_point gAMA)
+    png_colorspacerp colorspace, png_fixed_point gAMA)
 {
    /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't
     * occur.  Since the fixed point representation is asymmetrical it is
@@ -997,8 +997,13 @@ png_colorspace_set_gamma(png_const_structrp png_ptr,
     * In 1.6.0 this test replaces the ones in pngrutil.c, in the gAMA chunk
     * handling code, which only required the value to be >0.
     */
-#  define ERRMSG (defined PNG_TRANSFORM_MECH_SUPPORTED) &&\
-                 (defined PNG_ERROR_TEXT_SUPPORTED)
+#  if (defined PNG_TRANSFORM_MECH_SUPPORTED) &&\
+      (defined PNG_ERROR_TEXT_SUPPORTED)
+#     define ERRMSG 1
+#  else
+#     define ERRMSG 0
+#  endif
+
 #  if ERRMSG
       png_const_charp errmsg;
 #  endif
@@ -1574,8 +1579,8 @@ static const png_xy sRGB_xy = /* From ITU-R BT.709-3 */
 
 static int
 png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr,
-   png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ,
-   int preferred)
+    png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ,
+    int preferred)
 {
    if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
       return 0;
@@ -1622,7 +1627,7 @@ png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr,
 
 int /* PRIVATE */
 png_colorspace_set_chromaticities(png_const_structrp png_ptr,
-   png_colorspacerp colorspace, const png_xy *xy, int preferred)
+    png_colorspacerp colorspace, const png_xy *xy, int preferred)
 {
    /* We must check the end points to ensure they are reasonable - in the past
     * color management systems have crashed as a result of getting bogus
@@ -1636,7 +1641,7 @@ png_colorspace_set_chromaticities(png_const_structrp png_ptr,
    {
       case 0: /* success */
          return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, xy, &XYZ,
-            preferred);
+             preferred);
 
       case 1:
          /* We can't invert the chromaticities so we can't produce value XYZ
@@ -1660,7 +1665,7 @@ png_colorspace_set_chromaticities(png_const_structrp png_ptr,
 
 int /* PRIVATE */
 png_colorspace_set_endpoints(png_const_structrp png_ptr,
-   png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred)
+    png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred)
 {
    png_XYZ XYZ = *XYZ_in;
    png_xy xy;
@@ -1669,7 +1674,7 @@ png_colorspace_set_endpoints(png_const_structrp png_ptr,
    {
       case 0:
          return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, &xy, &XYZ,
-            preferred);
+             preferred);
 
       case 1:
          /* End points are invalid. */
@@ -1727,7 +1732,7 @@ is_ICC_signature(png_alloc_size_t it)
 
 static int
 png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
-   png_const_charp name, png_alloc_size_t value, png_const_charp reason)
+    png_const_charp name, png_alloc_size_t value, png_const_charp reason)
 {
    size_t pos;
    char message[196]; /* see below for calculation */
@@ -1752,8 +1757,8 @@ png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
          char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/
 
          pos = png_safecat(message, (sizeof message), pos,
-            png_format_number(number, number+(sizeof number),
-               PNG_NUMBER_FORMAT_x, value));
+             png_format_number(number, number+(sizeof number),
+             PNG_NUMBER_FORMAT_x, value));
          pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/
       }
 #  endif
@@ -1767,7 +1772,7 @@ png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
     * application errors the PNG won't be written.)
     */
    png_chunk_report(png_ptr, message,
-      (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR);
+       (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR);
 
    return 0;
 }
@@ -1776,7 +1781,7 @@ png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
 #ifdef PNG_sRGB_SUPPORTED
 int /* PRIVATE */
 png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace,
-   int intent)
+    int intent)
 {
    /* sRGB sets known gamma, end points and (from the chunk) intent. */
    /* IMPORTANT: these are not necessarily the values found in an ICC profile
@@ -1813,10 +1818,10 @@ png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace,
     */
    if (intent < 0 || intent >= PNG_sRGB_INTENT_LAST)
       return png_icc_profile_error(png_ptr, colorspace, "sRGB",
-         (unsigned)intent, "invalid sRGB rendering intent");
+          (unsigned)intent, "invalid sRGB rendering intent");
 
    if ((colorspace->flags & PNG_COLORSPACE_HAVE_INTENT) != 0 &&
-      colorspace->rendering_intent != intent)
+       colorspace->rendering_intent != intent)
       return png_icc_profile_error(png_ptr, colorspace, "sRGB",
          (unsigned)intent, "inconsistent rendering intents");
 
@@ -1830,8 +1835,8 @@ png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace,
     * warn but overwrite the value with the correct one.
     */
    if ((colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0 &&
-      !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy,
-         100))
+       !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy,
+       100))
       png_chunk_report(png_ptr, "cHRM chunk does not match sRGB",
          PNG_CHUNK_ERROR);
 
@@ -1839,7 +1844,7 @@ png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace,
     * returns true when the 'from' argument corresponds to sRGB (2).
     */
    (void)png_colorspace_check_gamma(png_ptr, colorspace, PNG_GAMMA_sRGB_INVERSE,
-      2/*from sRGB*/);
+       2/*from sRGB*/);
 
    /* intent: bugs in GCC force 'int' to be used as the parameter type. */
    colorspace->rendering_intent = png_check_u16(png_ptr, intent);
@@ -1874,23 +1879,23 @@ static const png_byte D50_nCIEXYZ[12] =
 
 int /* PRIVATE */
 png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
-   png_const_charp name, png_uint_32 profile_length)
+    png_const_charp name, png_uint_32 profile_length)
 {
    if (profile_length < 132)
       return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
-         "too short");
+          "too short");
 
    if (profile_length & 3)
       return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
-         "invalid length");
+          "invalid length");
 
    return 1;
 }
 
 int /* PRIVATE */
 png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
-   png_const_charp name, png_uint_32 profile_length,
-   png_const_bytep profile/* first 132 bytes only */, int is_color)
+    png_const_charp name, png_uint_32 profile_length,
+    png_const_bytep profile/* first 132 bytes only */, int is_color)
 {
    png_uint_32 temp;
 
@@ -1902,13 +1907,13 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
    temp = png_get_uint_32(profile);
    if (temp != profile_length)
       return png_icc_profile_error(png_ptr, colorspace, name, temp,
-         "length does not match profile");
+          "length does not match profile");
 
    temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */
    if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */
       profile_length < 132+12*temp) /* truncated tag table */
       return png_icc_profile_error(png_ptr, colorspace, name, temp,
-         "tag count too large");
+          "tag count too large");
 
    /* The 'intent' must be valid or we can't store it, ICC limits the intent to
     * 16 bits.
@@ -1916,14 +1921,14 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
    temp = png_get_uint_32(profile+64);
    if (temp >= 0xffff) /* The ICC limit */
       return png_icc_profile_error(png_ptr, colorspace, name, temp,
-         "invalid rendering intent");
+          "invalid rendering intent");
 
    /* This is just a warning because the profile may be valid in future
     * versions.
     */
    if (temp >= PNG_sRGB_INTENT_LAST)
       (void)png_icc_profile_error(png_ptr, NULL, name, temp,
-         "intent outside defined range");
+          "intent outside defined range");
 
    /* At this point the tag table can't be checked because it hasn't necessarily
     * been loaded; however, various header fields can be checked.  These checks
@@ -1940,7 +1945,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
    temp = png_get_uint_32(profile+36); /* signature 'ascp' */
    if (temp != 0x61637370)
       return png_icc_profile_error(png_ptr, colorspace, name, temp,
-         "invalid signature");
+          "invalid signature");
 
    /* Currently the PCS illuminant/adopted white point (the computational
     * white point) are required to be D50,
@@ -1951,7 +1956,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
     */
    if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0)
       (void)png_icc_profile_error(png_ptr, NULL, name, 0/*no tag value*/,
-         "PCS illuminant is not D50");
+          "PCS illuminant is not D50");
 
    /* The PNG spec requires this:
     * "If the iCCP chunk is present, the image samples conform to the colour
@@ -1979,18 +1984,18 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
       case 0x52474220: /* 'RGB ' */
          if (!is_color)
             return png_icc_profile_error(png_ptr, colorspace, name, temp,
-               "RGB color space not permitted on grayscale PNG");
+                "RGB color space not permitted on grayscale PNG");
          break;
 
       case 0x47524159: /* 'GRAY' */
          if (is_color)
             return png_icc_profile_error(png_ptr, colorspace, name, temp,
-               "Gray color space not permitted on RGB PNG");
+                "Gray color space not permitted on RGB PNG");
          break;
 
       default:
          return png_icc_profile_error(png_ptr, colorspace, name, temp,
-            "invalid ICC profile color space");
+             "invalid ICC profile color space");
    }
 
    /* It is up to the application to check that the profile class matches the
@@ -2015,7 +2020,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
       case 0x61627374: /* 'abst' */
          /* May not be embedded in an image */
          return png_icc_profile_error(png_ptr, colorspace, name, temp,
-            "invalid embedded Abstract ICC profile");
+             "invalid embedded Abstract ICC profile");
 
       case 0x6C696E6B: /* 'link' */
          /* DeviceLink profiles cannot be interpreted in a non-device specific
@@ -2025,7 +2030,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
           * PNG.
           */
          return png_icc_profile_error(png_ptr, colorspace, name, temp,
-            "unexpected DeviceLink ICC profile class");
+             "unexpected DeviceLink ICC profile class");
 
       case 0x6E6D636C: /* 'nmcl' */
          /* A NamedColor profile is also device specific, however it doesn't
@@ -2033,7 +2038,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
           * certainly it will fail the tests below.
           */
          (void)png_icc_profile_error(png_ptr, NULL, name, temp,
-            "unexpected NamedColor ICC profile class");
+             "unexpected NamedColor ICC profile class");
          break;
 
       default:
@@ -2043,7 +2048,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
           * understood profiles.
           */
          (void)png_icc_profile_error(png_ptr, NULL, name, temp,
-            "unrecognized ICC profile class");
+             "unrecognized ICC profile class");
          break;
    }
 
@@ -2059,7 +2064,7 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
 
       default:
          return png_icc_profile_error(png_ptr, colorspace, name, temp,
-            "unexpected ICC PCS encoding");
+             "unexpected ICC PCS encoding");
    }
 
    return 1;
@@ -2067,8 +2072,8 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
 
 int /* PRIVATE */
 png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace,
-   png_const_charp name, png_uint_32 profile_length,
-   png_const_bytep profile /* header plus whole tag table */)
+    png_const_charp name, png_uint_32 profile_length,
+    png_const_bytep profile /* header plus whole tag table */)
 {
    png_uint_32 tag_count = png_get_uint_32(profile+128);
    png_uint_32 itag;
@@ -2096,7 +2101,7 @@ png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace,
           * alignment.
           */
          (void)png_icc_profile_error(png_ptr, NULL, name, tag_id,
-            "ICC profile tag start not a multiple of 4");
+             "ICC profile tag start not a multiple of 4");
       }
 
       /* This is a hard error; potentially it can cause read outside the
@@ -2104,7 +2109,7 @@ png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace,
        */
       if (tag_start > profile_length || tag_length > profile_length - tag_start)
          return png_icc_profile_error(png_ptr, colorspace, name, tag_id,
-            "ICC profile tag outside profile");
+             "ICC profile tag outside profile");
    }
 
    return 1; /* success, maybe with warnings */
@@ -2132,22 +2137,22 @@ static const struct
     */
    /* adler32, crc32, MD5[4], intent, date, length, file-name */
    PNG_ICC_CHECKSUM(0x0a3fd9f6, 0x3b8772b9,
-      PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0,
-      "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc")
+       PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0,
+       "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc")
 
    /* ICC sRGB v2 perceptual no black-compensation: */
    PNG_ICC_CHECKSUM(0x4909e5e1, 0x427ebb21,
-      PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0,
-      "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc")
+       PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0,
+       "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc")
 
    PNG_ICC_CHECKSUM(0xfd2144a1, 0x306fd8ae,
-      PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0,
-      "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc")
+       PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0,
+       "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc")
 
    /* ICC sRGB v4 perceptual */
    PNG_ICC_CHECKSUM(0x209c35d2, 0xbbef7812,
-      PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0,
-      "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc")
+       PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0,
+       "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc")
 
    /* The following profiles have no known MD5 checksum. If there is a match
     * on the (empty) MD5 the other fields are used to attempt a match and
@@ -2155,8 +2160,8 @@ static const struct
     * which suggests that they were also made by Hewlett Packard.
     */
    PNG_ICC_CHECKSUM(0xa054d762, 0x5d5129ce,
-      PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0,
-      "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc")
+       PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0,
+       "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc")
 
    /* This is a 'mntr' (display) profile with a mediaWhitePointTag that does not
     * match the D50 PCS illuminant in the header (it is in fact the D65 values,
@@ -2166,17 +2171,17 @@ static const struct
     * chromaticAdaptationTag.
     */
    PNG_ICC_CHECKSUM(0xf784f3fb, 0x182ea552,
-      PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/,
-      "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual")
+       PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/,
+       "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual")
 
    PNG_ICC_CHECKSUM(0x0398f3fc, 0xf29e526d,
-      PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/,
-      "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative")
+       PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/,
+       "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative")
 };
 
 static int
 png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
-   png_const_bytep profile, uLong adler)
+    png_const_bytep profile, uLong adler)
 {
    /* The quick check is to verify just the MD5 signature and trust the
     * rest of the data.  Because the profile has already been verified for
@@ -2192,13 +2197,12 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
 #endif
    unsigned int i;
 
-#ifdef PNG_SET_OPTION_SUPPORTED
-   /* First see if PNG_SKIP_sRGB_CHECK_PROFILE has been set to "on" */
-   if (((png_ptr->options >> PNG_SKIP_sRGB_CHECK_PROFILE) & 3) ==
-               PNG_OPTION_ON)
-      return 0;
-#endif
-
+#  ifdef PNG_SET_OPTION_SUPPORTED
+#     ifdef PNG_SKIP_sRGB_CHECK_PROFILE
+         /* First see if PNG_SKIP_sRGB_CHECK_PROFILE has been set to "on" */
+         if (!png_ptr->skip_sRGB_profile_check)
+#     endif /* SKIP_sRGB_CHECK_PROFILE */
+#  endif /* SET_OPTION */
    for (i=0; i < (sizeof png_sRGB_checks) / (sizeof png_sRGB_checks[0]); ++i)
    {
       if (png_get_uint_32(profile+84) == png_sRGB_checks[i].md5[0] &&
@@ -2259,7 +2263,7 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
                       * which is made irrelevant by this error.
                       */
                      png_chunk_report(png_ptr, "known incorrect sRGB profile",
-                        PNG_CHUNK_ERROR);
+                         PNG_CHUNK_ERROR);
                   }
 
                   /* Warn that this being done; this isn't even an error since
@@ -2269,8 +2273,8 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
                   else if (png_sRGB_checks[i].have_md5 == 0)
                   {
                      png_chunk_report(png_ptr,
-                        "out-of-date sRGB profile with no signature",
-                        PNG_CHUNK_WARNING);
+                         "out-of-date sRGB profile with no signature",
+                         PNG_CHUNK_WARNING);
                   }
 
                   return 1+png_sRGB_checks[i].is_broken;
@@ -2293,38 +2297,36 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
 
    return 0; /* no match */
 }
-#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */
 
 void /* PRIVATE */
 png_icc_set_sRGB(png_const_structrp png_ptr,
-   png_colorspacerp colorspace, png_const_bytep profile, uLong adler)
+    png_colorspacerp colorspace, png_const_bytep profile, uLong adler)
 {
    /* Is this profile one of the known ICC sRGB profiles?  If it is, just set
     * the sRGB information.
     */
-#if PNG_sRGB_PROFILE_CHECKS >= 0
    if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler) != 0)
-#endif
       (void)png_colorspace_set_sRGB(png_ptr, colorspace,
          (int)/*already checked*/png_get_uint_32(profile+64));
 }
+#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */
 #endif /* sRGB */
 
 int /* PRIVATE */
 png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace,
-   png_const_charp name, png_uint_32 profile_length, png_const_bytep profile,
-   int is_color)
+    png_const_charp name, png_uint_32 profile_length, png_const_bytep profile,
+    int is_color)
 {
    if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
       return 0;
 
    if (png_icc_check_length(png_ptr, colorspace, name, profile_length) != 0 &&
        png_icc_check_header(png_ptr, colorspace, name, profile_length, profile,
-          is_color) != 0 &&
+           is_color) != 0 &&
        png_icc_check_tag_table(png_ptr, colorspace, name, profile_length,
-          profile) != 0)
+           profile) != 0)
    {
-#     ifdef PNG_sRGB_SUPPORTED
+#     if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0
          /* If no sRGB support, don't try storing sRGB information */
          png_icc_set_sRGB(png_ptr, colorspace, profile, 0);
 #     endif
@@ -2475,9 +2477,9 @@ png_copy_row(png_const_structrp png_ptr, png_bytep dp, png_const_bytep sp,
 
 void /* PRIVATE */
 png_check_IHDR(png_const_structrp png_ptr,
-   png_uint_32 width, png_uint_32 height, int bit_depth,
-   int color_type, int interlace_type, int compression_type,
-   int filter_type)
+    png_uint_32 width, png_uint_32 height, int bit_depth,
+    int color_type, int interlace_type, int compression_type,
+    int filter_type)
 {
    int error = 0;
 
@@ -2633,7 +2635,7 @@ png_check_IHDR(png_const_structrp png_ptr,
 
 int /* PRIVATE */
 png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
-   png_size_tp whereami)
+    png_size_tp whereami)
 {
    int state = *statep;
    png_size_t i = *whereami;
@@ -2789,7 +2791,7 @@ png_pow10(int power)
    if (power < 0)
    {
       if (power < DBL_MIN_10_EXP) return 0;
-      recip = 1, power = -power;
+      recip = 1; power = -power;
    }
 
    if (power > 0)
@@ -2867,7 +2869,9 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
             double test = png_pow10(exp_b10+1);
 
             if (test <= DBL_MAX)
-               ++exp_b10, base = test;
+            {
+               ++exp_b10; base = test;
+            }
 
             else
                break;
@@ -2881,7 +2885,10 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
           * test on DBL_MAX above.
           */
          fp /= base;
-         while (fp >= 1) fp /= 10, ++exp_b10;
+         while (fp >= 1)
+         {
+            fp /= 10; ++exp_b10;
+         }
 
          /* Because of the code above fp may, at this point, be
           * less than .1, this is ok because the code below can
@@ -2932,7 +2939,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
                      /* Rounding up to 10, handle that here. */
                      if (czero > 0)
                      {
-                        --czero, d = 1;
+                        --czero; d = 1;
                         if (cdigits == 0) --clead;
                      }
                      else
@@ -2946,7 +2953,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
 
                            else if (ch == 46)
                            {
-                              ch = *--ascii, ++size;
+                              ch = *--ascii; ++size;
                               /* Advance exp_b10 to '1', so that the
                                * decimal point happens after the
                                * previous digit.
@@ -2973,7 +2980,9 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
                               int ch = *--ascii;
 
                               if (ch == 46)
-                                 ++size, exp_b10 = 1;
+                              {
+                                 ++size; exp_b10 = 1;
+                              }
 
                               /* Else lost a leading zero, so 'exp_b10' is
                                * still ok at (-1)
@@ -3064,7 +3073,7 @@ png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
              */
             size -= cdigits;
 
-            *ascii++ = 69, --size;    /* 'E': PLUS 1 TOTAL 2+precision */
+            *ascii++ = 69; --size;    /* 'E': PLUS 1 TOTAL 2+precision */
 
             /* The following use of an unsigned temporary avoids ambiguities in
              * the signed arithmetic on exp_b10 and permits GCC at least to do
@@ -3180,7 +3189,10 @@ png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii,
                 * then ndigits digits to first:
                 */
                i = 5;
-               while (ndigits < i) *ascii++ = 48, --i;
+               while (ndigits < i)
+               {
+                  *ascii++ = 48; --i;
+               }
                while (ndigits >= first) *ascii++ = digits[--ndigits];
                /* Don't output the trailing zeros! */
             }
@@ -3355,74 +3367,136 @@ png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
 }
 #endif /* GAMMA || INCH_CONVERSIONS */
 
-/* HARDWARE OPTION SUPPORT */
-#ifdef PNG_SET_OPTION_SUPPORTED
-int PNGAPI
-png_set_option(png_structrp png_ptr, int option, int onoff)
-{
-   if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT &&
-      (option & 1) == 0)
-   {
-      unsigned int mask = 3U << option;
-      unsigned int setting = (2U + (onoff != 0)) << option;
-      unsigned int current = png_ptr->options;
-
-      png_ptr->options = (current & ~mask) | setting;
-
-      return (current & mask) >> option;
-   }
-
-   return PNG_OPTION_INVALID;
-}
-#endif /* SET_OPTION */
-
 /* SOFTWARE SETTING SUPPORT */
-#ifdef PNG_SETTING_SUPPORTED
 png_int_32 PNGAPI
-png_setting(png_structrp png_ptr, int setting, png_int_32 value)
+png_setting(png_structrp png_ptr, png_uint_32 setting, png_uint_32 parameter,
+      png_int_32 value)
 {
-   switch (setting)
+   png_int_32 result;
+
+   if (png_ptr != NULL)
    {
-#     ifdef PNG_READ_GAMMA_SUPPORTED
-         case PNG_GAMMA_MINIMUM:
-            if (value < 0 || value > 0xFFFF)
-               value = PNG_GAMMA_THRESHOLD_FIXED;
+      int handle_error = (setting & PNG_SF_ERROR) != 0U;
+
+      setting &= ~PNG_SF_ERROR; /* because it is handled below. */
+
+      switch (setting & (PNG_SF_READ|PNG_SF_WRITE))
+      {
+#        ifdef PNG_READ_SUPPORTED
+            case PNG_SF_READ:
+               if (png_ptr->read_struct)
+                  result = png_read_setting(png_ptr, setting, parameter, value);
+
+               else
+                  result = PNG_EINVAL; /* read setting on write struct */
+               break;
+#        endif /* READ */
+
+#        ifdef PNG_WRITE_SUPPORTED
+            case PNG_SF_WRITE:
+               if (!png_ptr->read_struct)
+                  result = png_write_setting(png_ptr, setting, parameter,
+                        value);
+
+               else
+                  result = PNG_EINVAL; /* write setting on read struct */
+               break;
+#        endif /* WRITE */
+
+         default:
+            /* Handle everything else here.  This includes the error of not
+             * having either read or write set; that error will cause a
+             * PNG_ENOSYS return code.
+             */
+            switch (setting)
             {
-               png_int_32 old = png_ptr->gamma_threshold;
-               png_ptr->gamma_threshold = PNG_UINT_16(value);
-               return old;
+#              ifdef PNG_SET_OPTION_SUPPORTED
+                  case PNG_SRW_OPTION:
+                     if (parameter >= PNG_OPTION_NEXT)
+                        return PNG_OPTION_INVALID;
+
+                     if (parameter == PNG_SKIP_sRGB_CHECK_PROFILE)
+                     {
+                        if (png_ptr->skip_sRGB_profile_check)
+                        {
+                           if (!value)
+                              png_ptr->skip_sRGB_profile_check = 0U;
+                           result = PNG_OPTION_ON;
+                        }
+
+                        else
+                        {
+                           if (value)
+                              png_ptr->skip_sRGB_profile_check = 1U;
+                           result = PNG_OPTION_OFF;
+                        }
+
+                        break;
+                     }
+
+#                    ifdef PNG_READ_SUPPORTED
+                        if (png_ptr->read_struct)
+                        {
+                           result = png_read_setting(png_ptr, setting,
+                                 parameter, value);
+                           break;
+                        }
+#                    endif /* READ */
+
+                     /* No write options at present */
+                     result = PNG_OPTION_UNSET; /* i.e. ignore it */
+                     break;
+#              endif /* SET_OPTION */
+
+               default:
+                  /* Any other option; handle in the appropriate setting: */
+#                 ifdef PNG_READ_SUPPORTED
+                     if (png_ptr->read_struct)
+                     {
+                        result = png_read_setting(png_ptr, setting,
+                              parameter, value);
+                        break;
+                     }
+#                 endif /* READ */
+
+#                 ifdef PNG_WRITE_SUPPORTED
+                     if (!png_ptr->read_struct)
+                     {
+                        result = png_write_setting(png_ptr, setting,
+                              parameter, value);
+                        break;
+                     }
+#                 endif /* WRITE */
+
+                  NOT_REACHED;
+                  result= PNG_ENOSYS;
+                  break;
             }
             break;
+      } /* switch */
 
-#if 0 /*NYI*/
-         case PNG_GAMMA_ACCURACY:
-            if (value < 0 || value > 1600)
-               value = PNG_DEFAULT_GAMMA_ACCURACY;
-            {
-               png_int_32 old = png_ptr->gamma_accuracy;
-               png_ptr->gamma_accuracy = value;
-               return old;
-            }
-            break;
-#endif /*NYI*/
-#     endif /* READ_GAMMA */
-
-      default:
-         break;
+      /* Handle error returns here.
+       * TODO: this is crude, should use a formatted warning style message and
+       * output result/setting/parameter/value.
+       */
+      if (handle_error && PNG_FAILED(result))
+         png_error(png_ptr, "png_setting");
    }
 
-   PNG_UNUSED(png_ptr)
+   else /* png_ptr is NULL */
+      result = PNG_EINVAL;
+
+   return result;
+   PNG_UNUSED(parameter)
    PNG_UNUSED(value)
-   return PNG_UNSUPPORTED_SETTING;
 }
-#endif /* SETTING */
 
 /* sRGB support */
 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
 /* sRGB conversion tables; these are machine generated with the code in
  * contrib/tools/makesRGB.c.  The actual sRGB transfer curve defined in the
- * specification (see the article at http://en.wikipedia.org/wiki/SRGB)
+ * specification (see the article at https://en.wikipedia.org/wiki/SRGB)
  * is used, not the gamma=1/2.2 approximation use elsewhere in libpng.
  * The sRGB to linear table is exact (to the nearest 16-bit linear fraction).
  * The inverse (linear to sRGB) table has accuracies as follows:

pngconf.h

@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.7.0beta80, May 6, 2016
+ * libpng version 1.7.0beta90, August 28, 2017
  *
  * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -188,27 +188,27 @@
    * compatible with GCC or Visual C because of different calling conventions.
    */
 #  if PNG_API_RULE == 2
-    /* If this line results in an error, either because __watcall is not
-     * understood or because of a redefine just below you cannot use *this*
-     * build of the library with the compiler you are using.  *This* build was
-     * build using Watcom and applications must also be built using Watcom!
-     */
+   /* If this line results in an error, either because __watcall is not
+    * understood or because of a redefine just below you cannot use *this*
+    * build of the library with the compiler you are using.  *This* build was
+    * build using Watcom and applications must also be built using Watcom!
+    */
 #    define PNGCAPI __watcall
 #  endif
 
 #  if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
 #    define PNGCAPI __cdecl
 #    if PNG_API_RULE == 1
-       /* If this line results in an error __stdcall is not understood and
-        * PNG_API_RULE should not have been set to '1'.
-        */
+   /* If this line results in an error __stdcall is not understood and
+    * PNG_API_RULE should not have been set to '1'.
+    */
 #      define PNGAPI __stdcall
 #    endif
 #  else
-    /* An older compiler, or one not detected (erroneously) above,
-     * if necessary override on the command line to get the correct
-     * variants for the compiler.
-     */
+   /* An older compiler, or one not detected (erroneously) above,
+    * if necessary override on the command line to get the correct
+    * variants for the compiler.
+    */
 #    ifndef PNGCAPI
 #      define PNGCAPI _cdecl
 #    endif
@@ -225,10 +225,10 @@
 
 #  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.
-     */
+   /* 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
@@ -244,9 +244,9 @@
 #  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
 #    define PNGAPI _System
 #  else /* !Windows/x86 && !OS/2 */
-    /* Use the defaults, or define PNG*API on the command line (but
-     * this will have to be done for every compile!)
-     */
+   /* Use the defaults, or define PNG*API on the command line (but
+    * this will have to be done for every compile!)
+    */
 #  endif /* other system, !OS/2 */
 #endif /* !Windows/x86 */
 
@@ -267,7 +267,7 @@
  */
 #ifndef PNG_IMPEXP
 #  if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
-     /* This forces use of a DLL, disallowing static linking */
+   /* This forces use of a DLL, disallowing static linking */
 #    define PNG_IMPEXP PNG_DLL_IMPORT
 #  endif
 
@@ -340,7 +340,7 @@
    * less efficient code.
    */
 #  if defined(__clang__) && defined(__has_attribute)
-     /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */
+   /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */
 #    if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__)
 #      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
 #    endif

pngdebug.h

@@ -35,9 +35,6 @@
 #define PNGDEBUG_H
 /* These settings control the formatting of messages in png.c and pngerror.c */
 /* Moved to pngdebug.h at 1.5.0 */
-#  ifndef PNG_LITERAL_SHARP
-#    define PNG_LITERAL_SHARP 0x23U
-#  endif
 #  ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
 #    define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5bU
 #  endif

pngerror.c

@@ -27,7 +27,7 @@ static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
 #ifdef PNG_WARNINGS_SUPPORTED
 static void /* PRIVATE */
 png_default_warning PNGARG((png_const_structrp png_ptr,
-   png_const_charp warning_message));
+    png_const_charp warning_message));
 #endif /* WARNINGS */
 
 /* This function is called whenever there is a fatal error.  This function
@@ -38,48 +38,8 @@ png_default_warning PNGARG((png_const_structrp png_ptr,
 #ifdef PNG_ERROR_TEXT_SUPPORTED
 PNG_FUNCTION(void,PNGAPI
 png_error,(png_const_structrp png_ptr, png_const_charp error_message),
-   PNG_NORETURN)
+    PNG_NORETURN)
 {
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   char msg[16];
-   if (png_ptr != NULL)
-   {
-      if ((png_ptr->flags &
-         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
-      {
-         if (*error_message == PNG_LITERAL_SHARP)
-         {
-            /* Strip "#nnnn " from beginning of error message. */
-            int offset;
-            for (offset = 1; offset<15; offset++)
-               if (error_message[offset] == ' ')
-                  break;
-
-            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
-            {
-               int i;
-               for (i = 0; i < offset - 1; i++)
-                  msg[i] = error_message[i + 1];
-               msg[i - 1] = '\0';
-               error_message = msg;
-            }
-
-            else
-               error_message += offset;
-      }
-
-      else
-      {
-         if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
-         {
-            msg[0] = '0';
-            msg[1] = '\0';
-            error_message = msg;
-         }
-       }
-     }
-   }
-#endif
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
       (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
           error_message);
@@ -111,7 +71,7 @@ png_err,(png_const_structrp png_ptr),PNG_NORETURN)
  */
 size_t
 png_safecat(png_charp buffer, size_t bufsize, size_t pos,
-   png_const_charp string)
+    png_const_charp string)
 {
    if (buffer != NULL && pos < bufsize)
    {
@@ -133,7 +93,7 @@ png_safecat(png_charp buffer, size_t bufsize, size_t pos,
 #define PNG_HAVE_FORMAT_NUMBER /* for the code below */
 png_charp
 png_format_number(png_const_charp start, png_charp end, int format,
-   png_alloc_size_t number)
+    png_alloc_size_t number)
 {
    int count = 0;    /* number of digits output */
    int mincount = 1; /* minimum number required */
@@ -218,24 +178,9 @@ void PNGAPI
 png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 {
    int offset = 0;
-   if (png_ptr != NULL)
-   {
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   if ((png_ptr->flags &
-       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
-#endif
-      {
-         if (*warning_message == PNG_LITERAL_SHARP)
-         {
-            for (offset = 1; offset < 15; offset++)
-               if (warning_message[offset] == ' ')
-                  break;
-         }
-      }
-   }
    if (png_ptr != NULL && png_ptr->warning_fn != NULL)
       (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
-         warning_message + offset);
+          warning_message + offset);
    else
       png_default_warning(png_ptr, warning_message + offset);
 }
@@ -247,7 +192,7 @@ png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
  */
 void
 png_warning_parameter(png_warning_parameters p, int number,
-   png_const_charp string)
+    png_const_charp string)
 {
    if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
       (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
@@ -255,7 +200,7 @@ png_warning_parameter(png_warning_parameters p, int number,
 
 void
 png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
-   png_alloc_size_t value)
+    png_alloc_size_t value)
 {
    char buffer[PNG_NUMBER_BUFFER_SIZE];
    png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
@@ -263,7 +208,7 @@ png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
 
 void
 png_warning_parameter_signed(png_warning_parameters p, int number, int format,
-   png_int_32 value)
+    png_int_32 value)
 {
    png_alloc_size_t u;
    png_charp str;
@@ -284,7 +229,7 @@ png_warning_parameter_signed(png_warning_parameters p, int number, int format,
 
 void
 png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
-   png_const_charp message)
+    png_const_charp message)
 {
    /* The internal buffer is just 192 bytes - enough for all our messages,
     * overflow doesn't happen because this code checks!  If someone figures
@@ -363,24 +308,41 @@ png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
 void PNGAPI
 png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
 {
-   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+   switch (png_ptr->benign_error_action)
    {
-#     ifdef PNG_READ_SUPPORTED
-         if (png_ptr->read_struct && png_ptr->chunk_name != 0)
-            png_chunk_warning(png_ptr, error_message);
-         else
-#     endif
-      png_warning(png_ptr, error_message);
+      case PNG_ERROR:
+         png_chunk_error(png_ptr, error_message);
+         break;
+
+      case PNG_WARN:
+         png_chunk_warning(png_ptr, error_message);
+         break;
+
+      default: /* PNG_IGNORE */
+         break;
    }
 
-   else
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+
+static void
+app_error(png_const_structrp png_ptr, png_const_charp error_message,
+      unsigned int error_action)
+{
+   switch (error_action)
    {
-#     ifdef PNG_READ_SUPPORTED
-         if (png_ptr->read_struct && png_ptr->chunk_name != 0)
-            png_chunk_error(png_ptr, error_message);
-         else
-#     endif
-      png_error(png_ptr, error_message);
+      case PNG_ERROR:
+         png_error(png_ptr, error_message);
+         break;
+
+      case PNG_WARN:
+         png_warning(png_ptr, error_message);
+         break;
+
+      default: /* PNG_IGNORE */
+         break;
    }
 
 #  ifndef PNG_ERROR_TEXT_SUPPORTED
@@ -391,27 +353,13 @@ png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
 void /* PRIVATE */
 png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
 {
-  if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0)
-     png_warning(png_ptr, error_message);
-  else
-     png_error(png_ptr, error_message);
-
-#  ifndef PNG_ERROR_TEXT_SUPPORTED
-      PNG_UNUSED(error_message)
-#  endif
+   app_error(png_ptr, error_message, png_ptr->app_warning_action);
 }
 
 void /* PRIVATE */
 png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
 {
-  if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0)
-     png_warning(png_ptr, error_message);
-  else
-     png_error(png_ptr, error_message);
-
-#  ifndef PNG_ERROR_TEXT_SUPPORTED
-      PNG_UNUSED(error_message)
-#  endif
+   app_error(png_ptr, error_message, png_ptr->app_error_action);
 }
 #endif /* BENIGN_ERRORS */
 
@@ -485,10 +433,10 @@ png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
 PNG_FUNCTION(void,PNGAPI
 png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
-   PNG_NORETURN)
+    PNG_NORETURN)
 {
    char msg[18+PNG_MAX_ERROR_TEXT];
-   if (png_ptr == NULL)
+   if (png_ptr == NULL || png_ptr->chunk_name == 0U)
       png_error(png_ptr, error_message);
 
    else
@@ -504,7 +452,7 @@ void PNGAPI
 png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 {
    char msg[18+PNG_MAX_ERROR_TEXT];
-   if (png_ptr == NULL)
+   if (png_ptr == NULL || png_ptr->chunk_name == 0U)
       png_warning(png_ptr, warning_message);
 
    else
@@ -521,17 +469,25 @@ void PNGAPI
 png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
     error_message)
 {
-   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
-      png_chunk_warning(png_ptr, error_message);
+   switch (png_ptr->benign_error_action)
+   {
+      case PNG_ERROR:
+         png_chunk_error(png_ptr, error_message);
+         break;
 
-   else
-      png_chunk_error(png_ptr, error_message);
+      case PNG_WARN:
+         png_chunk_warning(png_ptr, error_message);
+         break;
+
+      default: /* PNG_IGNORE */
+         break;
+   }
 
 #  ifndef PNG_ERROR_TEXT_SUPPORTED
       PNG_UNUSED(error_message)
 #  endif
 }
-#endif
+#endif /* BENIGN_ERRORS */
 #endif /* READ */
 
 void /* PRIVATE */
@@ -640,7 +596,7 @@ png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
       else
       {
          png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
-            png_malloc_warn(png_ptr, jmp_buf_size));
+             png_malloc_warn(png_ptr, jmp_buf_size));
 
          if (png_ptr->jmp_buf_ptr == NULL)
             return NULL; /* new NULL return on OOM */
@@ -729,40 +685,9 @@ png_free_jmpbuf(png_structrp png_ptr)
  */
 static PNG_FUNCTION(void /* PRIVATE */,
 png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
-   PNG_NORETURN)
+    PNG_NORETURN)
 {
 #ifdef PNG_CONSOLE_IO_SUPPORTED
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   /* Check on NULL only added in 1.5.4 */
-   if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
-   {
-      /* Strip "#nnnn " from beginning of error message. */
-      int offset;
-      char error_number[16];
-      for (offset = 0; offset<15; offset++)
-      {
-         error_number[offset] = error_message[offset + 1];
-         if (error_message[offset] == ' ')
-            break;
-      }
-
-      if ((offset > 1) && (offset < 15))
-      {
-         error_number[offset - 1] = '\0';
-         fprintf(stderr, "libpng error no. %s: %s",
-             error_number, error_message + offset + 1);
-         fprintf(stderr, PNG_STRING_NEWLINE);
-      }
-
-      else
-      {
-         fprintf(stderr, "libpng error: %s, offset=%d",
-             error_message, offset);
-         fprintf(stderr, PNG_STRING_NEWLINE);
-      }
-   }
-   else
-#endif
    {
       fprintf(stderr, "libpng error: %s", error_message ? error_message :
          "undefined");
@@ -809,36 +734,6 @@ static void /* PRIVATE */
 png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 {
 #ifdef PNG_CONSOLE_IO_SUPPORTED
-#  ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   if (*warning_message == PNG_LITERAL_SHARP)
-   {
-      int offset;
-      char warning_number[16];
-      for (offset = 0; offset < 15; offset++)
-      {
-         warning_number[offset] = warning_message[offset + 1];
-         if (warning_message[offset] == ' ')
-            break;
-      }
-
-      if ((offset > 1) && (offset < 15))
-      {
-         warning_number[offset + 1] = '\0';
-         fprintf(stderr, "libpng warning no. %s: %s",
-             warning_number, warning_message + offset);
-         fprintf(stderr, PNG_STRING_NEWLINE);
-      }
-
-      else
-      {
-         fprintf(stderr, "libpng warning: %s",
-             warning_message);
-         fprintf(stderr, PNG_STRING_NEWLINE);
-      }
-   }
-   else
-#  endif
-
    {
       fprintf(stderr, "libpng warning: %s", warning_message);
       fprintf(stderr, PNG_STRING_NEWLINE);
@@ -886,19 +781,6 @@ png_get_error_ptr(png_const_structrp png_ptr)
 }
 
 
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-void PNGAPI
-png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
-{
-   if (png_ptr != NULL)
-   {
-      png_ptr->flags &=
-         ((PNG_BIC_MASK(PNG_FLAG_STRIP_ERROR_NUMBERS |
-         PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
-   }
-}
-#endif
-
 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
    /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
@@ -907,7 +789,7 @@ png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
     */
 PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
 png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
-   PNG_NORETURN)
+    PNG_NORETURN)
 {
    const png_const_structrp png_ptr = png_nonconst_ptr;
    png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
@@ -930,7 +812,7 @@ png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
       /* Missing longjmp buffer, the following is to help debugging: */
       {
          size_t pos = png_safecat(image->message, (sizeof image->message), 0,
-            "bad longjmp: ");
+             "bad longjmp: ");
          png_safecat(image->message, (sizeof image->message), pos,
              error_message);
       }

pngget.c

@@ -499,7 +499,7 @@ png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
 #ifdef PNG_bKGD_SUPPORTED
 png_uint_32 PNGAPI
 png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
-   png_color_16p *background)
+    png_color_16p *background)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
        (info_ptr->valid & PNG_INFO_bKGD) != 0 &&
@@ -539,28 +539,28 @@ png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
       if (white_x != NULL)
          *white_x = png_float(png_ptr,
-            info_ptr->colorspace.end_points_xy.whitex, "cHRM white X");
+             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");
+             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");
+             "cHRM red X");
       if (red_y != NULL)
          *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy,
-            "cHRM red Y");
+             "cHRM red Y");
       if (green_x != NULL)
          *green_x = png_float(png_ptr,
-            info_ptr->colorspace.end_points_xy.greenx, "cHRM green X");
+             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");
+             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");
+             "cHRM blue X");
       if (blue_y != NULL)
          *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey,
-            "cHRM blue Y");
+             "cHRM blue Y");
       return (PNG_INFO_cHRM);
    }
 
@@ -569,42 +569,42 @@ png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 png_uint_32 PNGAPI
 png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
-   double *red_X, double *red_Y, double *red_Z, double *green_X,
-   double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
-   double *blue_Z)
+    double *red_X, double *red_Y, double *red_Z, double *green_X,
+    double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
+    double *blue_Z)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+       (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
    {
       png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
 
       if (red_X != NULL)
          *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
-            "cHRM 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");
+             "cHRM red Y");
       if (red_Z != NULL)
          *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
-            "cHRM 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");
+             info_ptr->colorspace.end_points_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");
+             info_ptr->colorspace.end_points_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");
+             info_ptr->colorspace.end_points_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");
+             info_ptr->colorspace.end_points_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");
+             info_ptr->colorspace.end_points_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");
+             info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z");
       return (PNG_INFO_cHRM);
    }
 
@@ -694,8 +694,8 @@ png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_debug1(1, "in %s retrieval function", "gAMA");
 
    if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
-      file_gamma != NULL)
+       (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
+       file_gamma != NULL)
    {
       *file_gamma = info_ptr->colorspace.gamma;
       return (PNG_INFO_gAMA);
@@ -717,7 +717,7 @@ png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
       file_gamma != NULL)
    {
       *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma,
-         "png_get_gAMA");
+          "png_get_gAMA");
       return (PNG_INFO_gAMA);
    }
 
@@ -904,7 +904,7 @@ png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
        */
       *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width");
       *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height),
-         "sCAL height");
+          "sCAL height");
       return (PNG_INFO_sCAL);
    }
 

pngmem.c

@@ -67,7 +67,7 @@ png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
  */
 PNG_FUNCTION(png_voidp /* PRIVATE */,
 png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
-   PNG_ALLOCATED)
+    PNG_ALLOCATED)
 {
    /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
     * allocators have also been removed in 1.6.0, so any 16-bit system now has
@@ -112,7 +112,7 @@ png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
  */
 static png_voidp
 png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
-   size_t element_size)
+    size_t element_size)
 {
    png_alloc_size_t req = nelements; /* known to be > 0 */
 
@@ -125,7 +125,7 @@ png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
 
 PNG_FUNCTION(png_voidp /* PRIVATE */,
 png_malloc_array,(png_const_structrp png_ptr, int nelements,
-   size_t element_size),PNG_ALLOCATED)
+    size_t element_size),PNG_ALLOCATED)
 {
    affirm(nelements > 0 && element_size > 0);
    return png_malloc_array_checked(png_ptr, nelements, element_size);
@@ -133,7 +133,7 @@ png_malloc_array,(png_const_structrp png_ptr, int nelements,
 
 PNG_FUNCTION(png_voidp /* PRIVATE */,
 png_realloc_array,(png_structrp png_ptr, png_const_voidp old_array,
-   int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
+    int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
 {
    /* These are internal errors: */
    affirm(add_elements > 0 && element_size > 0 && old_elements >= 0 &&
@@ -145,7 +145,7 @@ png_realloc_array,(png_structrp png_ptr, png_const_voidp old_array,
    if (add_elements <= INT_MAX - old_elements)
    {
       png_voidp new_array = png_malloc_array_checked(png_ptr,
-         old_elements+add_elements, element_size);
+          old_elements+add_elements, element_size);
 
       if (new_array != NULL)
       {
@@ -156,7 +156,7 @@ png_realloc_array,(png_structrp png_ptr, png_const_voidp old_array,
             memcpy(new_array, old_array, element_size*(unsigned)old_elements);
 
          memset((char*)new_array + element_size*(unsigned)old_elements, 0,
-            element_size*(unsigned)add_elements);
+             element_size*(unsigned)add_elements);
 
          return new_array;
       }
@@ -201,7 +201,7 @@ png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
  */
 PNG_FUNCTION(png_voidp,PNGAPI
 png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
-   PNG_ALLOCATED)
+    PNG_ALLOCATED)
 {
    if (png_ptr != NULL)
    {

pngpread.c

@@ -26,7 +26,9 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       return;
 
    ptr = buffer;
-   if (png_ptr->save_buffer_size != 0)
+   debug(length > 0);
+
+   if (length > 0 && png_ptr->save_buffer_size > 0)
    {
       png_size_t save_size;
 
@@ -44,7 +46,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       png_ptr->save_buffer_ptr += save_size;
    }
 
-   if (length != 0 && png_ptr->current_buffer_size != 0)
+   if (length > 0 && png_ptr->current_buffer_size > 0)
    {
       png_size_t save_size;
 
@@ -193,7 +195,7 @@ png_process_data_skip(png_structrp png_ptr)
 
 static void
 png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer,
-   png_size_t buffer_length)
+    png_size_t buffer_length)
 {
    png_ptr->current_buffer_size = buffer_length;
    png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
@@ -734,15 +736,15 @@ png_push_read_chunk_header(png_structrp png_ptr, png_infop info_ptr)
     * of the data.
     */
    unsigned int mode; /* mode prior to the header */
-   png_byte chunk_length[4];
-   png_byte chunk_tag[4];
+   png_byte chunk_header[8];
 
    PNG_PUSH_SAVE_BUFFER_IF_LT(8)
-   png_push_fill_buffer(png_ptr, chunk_length, 4);
-   png_ptr->chunk_length = png_get_uint_31(png_ptr, chunk_length);
-   png_reset_crc(png_ptr);
-   png_crc_read(png_ptr, chunk_tag, 4);
-   png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+   png_push_fill_buffer(png_ptr, chunk_header, 8);
+   png_ptr->chunk_length = png_get_uint_31(png_ptr, chunk_header);
+   png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_header+4);
+   png_reset_crc(png_ptr, chunk_header+4);
+   png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+   png_check_chunk_length(png_ptr, png_ptr->chunk_length);
    mode = png_ptr->mode;
    png_ptr->process_mode = png_check_bits(png_ptr,
       png_read_chunk+png_find_chunk_op(png_ptr), 4);

pngpriv.h

@@ -319,9 +319,13 @@
  * is just the affirm code; there's no reason to allow configuration of this
  * option.
  */
-#define PNG_AFFIRM_TEXT (PNG_RELEASE_BUILD ?\
-         (defined PNG_ERROR_TEXT_SUPPORTED) :\
-         (defined PNG_WARNINGS_SUPPORTED) || (defined PNG_CONSOLE_IO_SUPPORTED))
+#if PNG_RELEASE_BUILD ?\
+      (defined PNG_ERROR_TEXT_SUPPORTED) :\
+      (defined PNG_WARNINGS_SUPPORTED) || (defined PNG_CONSOLE_IO_SUPPORTED)
+#  define PNG_AFFIRM_TEXT 1
+#else
+#  define PNG_AFFIRM_TEXT 0
+#endif /* PNG_AFFIRM_TEXT definition */
 
 #define PNG_SRC_LINE (PNG_SRC_FILE + __LINE__)
 
@@ -390,7 +394,7 @@
 #define PNG_SRC_FILE_pngwtran (PNG_SRC_FILE_pngwrite +4096)
 #define PNG_SRC_FILE_pngwutil (PNG_SRC_FILE_pngwtran +1024)
 
-#define PNG_SRC_FILE_arm_arm_init (PNG_SRC_FILE_pngwutil +4096)
+#define PNG_SRC_FILE_arm_arm_init (PNG_SRC_FILE_pngwutil +8192)
 #define PNG_SRC_FILE_arm_filter_neon_intrinsics\
              (PNG_SRC_FILE_arm_arm_init +1024)
 
@@ -618,28 +622,6 @@
 #define PNG_HAVE_IEND               0x10U
 #define PNG_HAVE_PNG_SIGNATURE      0x20U
 
-/* Flags for the png_ptr->flags.
- * TODO: change to bit fields.
- */
-#define PNG_FLAG_LIBRARY_MISMATCH         0x001U
-/*#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY   0x002U NO LONGER USED */
-#define PNG_FLAG_CRC_ANCILLARY_USE        0x004U
-#define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x008U
-#define PNG_FLAG_CRC_CRITICAL_USE         0x010U
-#define PNG_FLAG_CRC_CRITICAL_IGNORE      0x020U
-#define PNG_FLAG_STRIP_ERROR_NUMBERS      0x040U
-#define PNG_FLAG_STRIP_ERROR_TEXT         0x080U
-#define PNG_FLAG_IDAT_ERRORS_WARN         0x100U
-#define PNG_FLAG_BENIGN_ERRORS_WARN       0x200U
-#define PNG_FLAG_APP_WARNINGS_WARN        0x400U
-#define PNG_FLAG_APP_ERRORS_WARN          0x800U
-
-#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
-                                     PNG_FLAG_CRC_ANCILLARY_NOWARN)
-
-#define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
-                                     PNG_FLAG_CRC_CRITICAL_IGNORE)
-
 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
 /* See below for the definitions of the tables used in these macros */
@@ -974,12 +956,6 @@ PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
    double fp, png_const_charp text),PNG_EMPTY);
 #endif
 
-/* Check the user version string for compatibility, returns false if the version
- * numbers aren't compatible.
- */
-PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
-   png_const_charp user_png_ver),PNG_EMPTY);
-
 /* Internal base allocator - no messages, NULL on failure to allocate.  This
  * does, however, call the application provided allocator and that could call
  * png_error (although that would be a bug in the application implementation.)
@@ -1050,8 +1026,12 @@ PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
 #  endif /* WRITE */
 #endif /* STDIO */
 
-/* Reset the CRC variable */
-PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
+/* Reset the CRC variable.  The CRC is initialized with the chunk tag (4 bytes).
+ * NOTE: at present png_struct::chunk_name MUST be set before this as well so
+ * that png_struct::current_crc is initialized correctly!
+ */
+PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr,
+         png_const_bytep chunk_tag), PNG_EMPTY);
 
 /* Write the "data" buffer to whatever output you are using */
 PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
@@ -1107,7 +1087,7 @@ PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
 #ifdef PNG_WRITE_cHRM_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
     const png_xy *xy), PNG_EMPTY);
-    /* The xy value must have been previously validated */
+   /* The xy value must have been previously validated */
 #endif
 
 #ifdef PNG_WRITE_sRGB_SUPPORTED
@@ -1378,7 +1358,12 @@ PNG_INTERNAL_FUNCTION(png_transformp,png_add_transform,(png_structrp png_ptr,
     *
     *    PNG_RWTR_CHECK_PALETTE PI W11: happens in pngwrite.c last
     */
-#  define PNG_TR_INIT_ALPHA     (PNG_TR_START + 0x0300U)
+#  define PNG_TR_START_CACHE    (PNG_TR_START + 0x0300U)
+   /* Not used on a transform; this is just a marker for the point at which
+    * palette or low-bit-depth caching can start on read.  (The previous
+    * operations cannot be cached).
+    */
+#  define PNG_TR_INIT_ALPHA     (PNG_TR_START + 0x0400U)
    /* This just handles alpha/tRNS initialization issues to resolve the
     * inter-dependencies with tRNS expansion and background composition; it
     * doesn't do anything itself, just sets flags and pushes transforms.
@@ -1726,7 +1711,6 @@ PNG_INTERNAL_FUNCTION(int,png_read_finish_IDAT,(png_structrp png_ptr),
     *           is more IDAT data available the caller should output an
     *           appropriate (too much IDAT) error message.
     */
-#endif /* READ */
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_cache_known_unknown,(png_structrp png_ptr,
@@ -1753,6 +1737,12 @@ PNG_INTERNAL_FUNCTION(png_chunk_op,png_find_chunk_op,(png_structrp png_ptr),
     * read state.
     */
 
+PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_const_structrp png_ptr,
+    const png_uint_32 chunk_name),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_check_chunk_length,(png_const_structrp png_ptr,
+    const png_uint_32 chunk_length),PNG_EMPTY);
+
 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
    png_inforp info_ptr, png_bytep chunk_data),PNG_EMPTY);
@@ -1771,6 +1761,7 @@ PNG_INTERNAL_FUNCTION(void,png_handle_chunk,(png_structrp png_ptr,
     * has returned png_chunk_process_all and all the data is available for
     * png_handle_chunk (via the libpng read callback.)
     */
+#endif /* READ */
 
 PNG_INTERNAL_FUNCTION(void,png_init_row_info,(png_structrp png_ptr),PNG_EMPTY);
    /* Set the png_struct::row_ members from the PNG file information, running
@@ -1788,13 +1779,13 @@ PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
 
 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
     png_inforp info_ptr), PNG_EMPTY);
-    /* Synchronize the info 'valid' flags with the colorspace */
+   /* Synchronize the info 'valid' flags with the colorspace */
 
 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
     png_inforp info_ptr), PNG_EMPTY);
-    /* Copy the png_struct colorspace to the info_struct and call the above to
-     * synchronize the flags.  Checks for NULL info_ptr and does nothing.
-     */
+   /* Copy the png_struct colorspace to the info_struct and call the above to
+    * synchronize the flags.  Checks for NULL info_ptr and does nothing.
+    */
 #endif
 
 /* Added at libpng version 1.4.0 */
@@ -2136,6 +2127,14 @@ PNG_INTERNAL_FUNCTION(unsigned int,png_gamma_nxmbit_correct,
    /* In this case the value must have 'n' bits and the output will have 'm'
     * bits.
     */
+
+#if !PNG_RELEASE_BUILD
+PNG_INTERNAL_FUNCTION(int,png_gamma_check,(png_const_structrp png_ptr,
+   png_const_transform_controlp tc),PNG_EMPTY);
+   /* Debugging only routine to repeat the test used above to determine if the
+    * gamma was insignificant.
+    */
+#endif /* !RELEASE_BUILD */
 #endif /* READ_GAMMA */
 
 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
@@ -2225,6 +2224,20 @@ PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
 
 #endif /* SIMPLIFIED READ/WRITE */
 
+#ifdef PNG_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(png_int_32, png_read_setting, (png_structrp png_ptr,
+   png_uint_32 setting, png_uint_32 parameter, png_int_32 value), PNG_EMPTY);
+#endif /* READ */
+#ifdef PNG_WRITE_SUPPORTED
+PNG_INTERNAL_FUNCTION(png_int_32,  png_write_setting, (png_structrp png_ptr,
+   png_uint_32 setting, png_uint_32 parameter, png_int_32 value), PNG_EMPTY);
+   /* Implementations of read and write settings, in pngrutil.c and pngwutil.c
+    * respectively.
+    */
+#endif /* WRITE */
+
+/* Maintainer: Put new private prototypes here ^ */
+
 /* These are initialization functions for hardware specific PNG filter
  * optimizations; list these here then select the appropriate one at compile
  * time using the macro PNG_FILTER_OPTIMIZATIONS.  If the macro is not defined
@@ -2243,8 +2256,6 @@ PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
 #endif
 
-/* Maintainer: Put new private prototypes here ^ */
-
 #include "pngdebug.h"
 
 /* EXTENSION SPECIFIC FUNCTIONS */

pngread.c

@@ -21,75 +21,6 @@
 #define PNG_SRC_FILE PNG_SRC_FILE_pngread
 
 #ifdef PNG_READ_SUPPORTED
-
-/* Set the action on getting a CRC error for an ancillary or critical chunk. */
-void PNGAPI
-png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
-{
-   png_debug(1, "in png_set_crc_action");
-
-   if (png_ptr == NULL)
-      return;
-
-   /* Tell libpng how we react to CRC errors in critical chunks */
-   switch (crit_action)
-   {
-      case PNG_CRC_NO_CHANGE:                        /* Leave setting as is */
-         break;
-
-      case PNG_CRC_WARN_USE:                               /* Warn/use data */
-         png_ptr->flags &= PNG_BIC_MASK(PNG_FLAG_CRC_CRITICAL_MASK);
-         png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
-         break;
-
-      case PNG_CRC_QUIET_USE:                             /* Quiet/use data */
-         png_ptr->flags &= PNG_BIC_MASK(PNG_FLAG_CRC_CRITICAL_MASK);
-         png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
-                           PNG_FLAG_CRC_CRITICAL_IGNORE;
-         break;
-
-      case PNG_CRC_WARN_DISCARD:    /* Not a valid action for critical data */
-         png_warning(png_ptr,
-            "Can't discard critical data on CRC error");
-      case PNG_CRC_ERROR_QUIT:                                /* Error/quit */
-
-      case PNG_CRC_DEFAULT:
-      default:
-         png_ptr->flags &= PNG_BIC_MASK(PNG_FLAG_CRC_CRITICAL_MASK);
-         break;
-   }
-
-   /* Tell libpng how we react to CRC errors in ancillary chunks */
-   switch (ancil_action)
-   {
-      case PNG_CRC_NO_CHANGE:                       /* Leave setting as is */
-         break;
-
-      case PNG_CRC_WARN_USE:                              /* Warn/use data */
-         png_ptr->flags &= PNG_BIC_MASK(PNG_FLAG_CRC_ANCILLARY_MASK);
-         png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
-         break;
-
-      case PNG_CRC_QUIET_USE:                            /* Quiet/use data */
-         png_ptr->flags &= PNG_BIC_MASK(PNG_FLAG_CRC_ANCILLARY_MASK);
-         png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
-                           PNG_FLAG_CRC_ANCILLARY_NOWARN;
-         break;
-
-      case PNG_CRC_ERROR_QUIT:                               /* Error/quit */
-         png_ptr->flags &= PNG_BIC_MASK(PNG_FLAG_CRC_ANCILLARY_MASK);
-         png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
-         break;
-
-      case PNG_CRC_WARN_DISCARD:                      /* Warn/discard data */
-
-      case PNG_CRC_DEFAULT:
-      default:
-         png_ptr->flags &= PNG_BIC_MASK(PNG_FLAG_CRC_ANCILLARY_MASK);
-         break;
-   }
-}
-
 /* Create a PNG structure for reading, and allocate any memory needed. */
 PNG_FUNCTION(png_structp,PNGAPI
 png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
@@ -97,10 +28,10 @@ png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
 {
 #ifndef PNG_USER_MEM_SUPPORTED
    png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
-      error_fn, warn_fn, NULL, NULL, NULL);
+        error_fn, warn_fn, NULL, NULL, NULL);
 #else
    return png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
-       warn_fn, NULL, NULL, NULL);
+        warn_fn, NULL, NULL, NULL);
 }
 
 /* Alternate create PNG structure for reading, and allocate any memory
@@ -112,36 +43,48 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
     png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
 {
    png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
-      error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
+       error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
 #endif /* USER_MEM */
 
    if (png_ptr != NULL)
    {
       png_ptr->read_struct = 1;
+      png_ptr->critical_crc = crc_error_quit;
+      png_ptr->ancillary_crc = crc_warn_discard;
+
+#     ifdef PNG_BENIGN_ERRORS_SUPPORTED
+#        if !PNG_RELEASE_BUILD
+            /* Always quit on error prior to release */
+            png_ptr->benign_error_action = PNG_ERROR;
+            png_ptr->app_warning_action = PNG_WARN;
+            png_ptr->app_error_action = PNG_ERROR;
+#        else /* RELEASE_BUILD */
+            /* Allow benign errors on read, subject to app control. */
+            png_ptr->benign_error_action = PNG_WARN;
+#           ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED
+               png_ptr->app_error_action = PNG_WARN;
+               png_ptr->app_warning_action = PNG_WARN;
+#           else /* !BENIGN_READ_ERRORS */
+               /* libpng build without benign error support; the application
+                * author has to be assumed to be correct, so:
+                */
+               png_ptr->app_warning_action = PNG_WARN;
+               png_ptr->app_error_action = PNG_ERROR;
+#           endif /* !BENIGN_READ_ERRORS */
+#        endif /* RELEASE_BUILD */
+
+         /* This is always png_error unless explicitly changed: */
+         png_ptr->IDAT_error_action = PNG_ERROR;
+#     endif /* BENIGN_ERRORS */
 
-      /* Added in libpng-1.6.0; this can be used to detect a read structure if
-       * required (it will be zero in a write structure.)
-       */
 #  ifdef PNG_SEQUENTIAL_READ_SUPPORTED
       png_ptr->IDAT_size = PNG_IDAT_READ_SIZE;
 #  endif /* SEQUENTIAL_READ */
 
-#  ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED
-      png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
-      png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
-
-      /* In stable builds only warn if an application error can be completely
-       * handled.
-       */
-#     if PNG_RELEASE_BUILD
-         png_ptr->flags |= PNG_FLAG_APP_ERRORS_WARN;
-#     endif
-#  endif /* BENIGN_READ_ERRORS */
-
 #  ifdef PNG_READ_GAMMA_SUPPORTED
       /* Default gamma correction values: */
 #     if 0 /*NYI*/
-      png_ptr->gamma_accuracy = PNG_DEFAULT_GAMMA_ACCURACY;
+         png_ptr->gamma_accuracy = PNG_DEFAULT_GAMMA_ACCURACY;
 #     endif /*NYI*/
       png_ptr->gamma_threshold = PNG_GAMMA_THRESHOLD_FIXED;
 #  endif /* READ_GAMMA */
@@ -178,8 +121,7 @@ png_read_chunk_header(png_structrp png_ptr)
        (unsigned long)png_ptr->chunk_length);
 
    /* Reset the crc and run it over the chunk name. */
-   png_reset_crc(png_ptr);
-   png_calculate_crc(png_ptr, buf + 4, 4);
+   png_reset_crc(png_ptr, buf + 4);
 
 #ifdef PNG_IO_STATE_SUPPORTED
    png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
@@ -196,7 +138,9 @@ png_read_sequential_unknown(png_structrp png_ptr, png_inforp info_ptr)
 
    if (buffer != NULL)
    {
-      png_crc_read(png_ptr, buffer, png_ptr->chunk_length);
+      if (png_ptr->chunk_length > 0U)
+         png_crc_read(png_ptr, buffer, png_ptr->chunk_length);
+
       png_crc_finish(png_ptr, 0);
       png_handle_unknown(png_ptr, info_ptr, buffer);
    }
@@ -301,7 +245,7 @@ png_start_read_image(png_structrp png_ptr)
        */
       else
          png_app_error(png_ptr,
-            "png_start_read_image/png_read_update_info: duplicate call");
+             "png_start_read_image/png_read_update_info: duplicate call");
    }
 }
 
@@ -323,7 +267,7 @@ png_read_IDAT(png_structrp png_ptr)
    {
       png_uint_32 l = png_ptr->chunk_length;
 
-      if (l == 0) /* end of this IDAT */
+      while (l == 0) /* end of this IDAT */
       {
          png_crc_finish(png_ptr, 0);
          png_read_chunk_header(png_ptr);
@@ -331,7 +275,7 @@ png_read_IDAT(png_structrp png_ptr)
          if (png_ptr->chunk_name != png_IDAT) /* end of all IDAT */
          {
             png_ptr->mode |= PNG_AFTER_IDAT;
-            break;
+            goto done;
          }
 
          l = png_ptr->chunk_length;
@@ -346,6 +290,7 @@ png_read_IDAT(png_structrp png_ptr)
       IDAT_size += (uInt)/*SAFE*/l;
       png_ptr->chunk_length -= l;
    }
+done:
 
    /* IDAT_size may be zero if the compressed image stream is truncated;
     * this is likely given a broken PNG.
@@ -834,7 +779,7 @@ png_gt(size_t a, size_t b)
 
 void PNGAPI
 png_read_png(png_structrp png_ptr, png_inforp info_ptr, int transforms,
-   voidp params)
+    voidp params)
 {
    if (png_ptr == NULL || info_ptr == NULL)
       return;
@@ -1110,7 +1055,7 @@ png_image_read_init(png_imagep image)
          if (info_ptr != NULL)
          {
             png_controlp control = png_voidcast(png_controlp,
-               png_malloc_warn(png_ptr, (sizeof *control)));
+                png_malloc_warn(png_ptr, (sizeof *control)));
 
             if (control != NULL)
             {
@@ -1186,7 +1131,9 @@ png_image_read_header(png_voidp argument)
    png_structrp png_ptr = image->opaque->png_ptr;
    png_inforp info_ptr = image->opaque->info_ptr;
 
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
    png_set_benign_errors(png_ptr, 1/*warn*/);
+#endif
    png_read_info(png_ptr, info_ptr);
 
    /* Do this the fast way; just read directly out of png_struct. */
@@ -1297,12 +1244,12 @@ png_image_begin_read_from_stdio(png_imagep image, FILE* file)
 
       else
          return png_image_error(image,
-            "png_image_begin_read_from_stdio: invalid argument");
+             "png_image_begin_read_from_stdio: invalid argument");
    }
 
    else if (image != NULL)
       return png_image_error(image,
-         "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION");
+          "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION");
 
    return 0;
 }
@@ -1335,12 +1282,12 @@ png_image_begin_read_from_file(png_imagep image, const char *file_name)
 
       else
          return png_image_error(image,
-            "png_image_begin_read_from_file: invalid argument");
+             "png_image_begin_read_from_file: invalid argument");
    }
 
    else if (image != NULL)
       return png_image_error(image,
-         "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION");
+          "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION");
 
    return 0;
 }
@@ -1389,7 +1336,7 @@ image_init_memory_io(png_voidp param)
 
 int PNGAPI
 png_image_begin_read_from_memory(png_imagep image, png_const_voidp memory,
-      png_size_t size)
+    png_size_t size)
 {
    if (image != NULL && image->version == PNG_IMAGE_VERSION)
    {
@@ -1411,12 +1358,12 @@ png_image_begin_read_from_memory(png_imagep image, png_const_voidp memory,
 
       else
          return png_image_error(image,
-            "png_image_begin_read_from_memory: invalid argument");
+             "png_image_begin_read_from_memory: invalid argument");
    }
 
    else if (image != NULL)
       return png_image_error(image,
-         "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION");
+          "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION");
 
    return 0;
 }
@@ -1462,12 +1409,12 @@ png_image_skip_unused_chunks(png_structrp png_ptr)
         * IHDR, PLTE, tRNS, IDAT, and IEND chunks.
         */
        png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER,
-         NULL, -1);
+           NULL, -1);
 
        /* But do not ignore image data handling chunks */
        png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT,
-         chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5);
-    }
+           chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5);
+   }
 }
 
 #  define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p)
@@ -1669,7 +1616,7 @@ decode_gamma(png_image_read_control *display, png_uint_32 value,
 
       default:
          png_impossiblepp(display->image->opaque->png_ptr,
-            "unexpected encoding");
+             "unexpected encoding");
          break;
    }
 
@@ -1678,9 +1625,9 @@ decode_gamma(png_image_read_control *display, png_uint_32 value,
 
 static png_uint_32
 png_colormap_compose(png_image_read_control *display,
-   png_uint_32 foreground, unsigned int foreground_significant_bits,
-   int foreground_encoding, png_uint_32 alpha,
-   png_uint_32 background, int encoding)
+    png_uint_32 foreground, unsigned int foreground_significant_bits,
+    int foreground_encoding, png_uint_32 alpha,
+    png_uint_32 background, int encoding)
 {
    /* The file value is composed on the background, the background has the given
     * encoding and so does the result, the file is encoded with P_FILE and the
@@ -1717,21 +1664,21 @@ png_colormap_compose(png_image_read_control *display,
  */
 static void
 png_create_colormap_entry(png_image_read_control *display,
-   png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue,
-   png_uint_32 alpha, int encoding)
+    png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue,
+    png_uint_32 alpha, int encoding)
 {
    png_imagep image = display->image;
 #  define png_ptr image->opaque->png_ptr /* for error messages */
    const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
       P_LINEAR : P_sRGB;
    const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 &&
-      (red != green || green != blue);
+       (red != green || green != blue);
    int use_sBIT = encoding == P_FILE;
 
    affirm(ip <= 255);
    implies(encoding != P_LINEAR, red <= 255U && green <= 255U && blue <= 255U
-         && display->sBIT[0] <= 8U && display->sBIT[1] <= 8U
-         && display->sBIT[2] <= 8U && display->sBIT[3] <= 8U);
+        && display->sBIT[0] <= 8U && display->sBIT[1] <= 8U
+        && display->sBIT[2] <= 8U && display->sBIT[3] <= 8U);
 
    /* This is a hack for the grayscale colormap below. */
    if (encoding == P_FILE8)
@@ -1756,11 +1703,11 @@ png_create_colormap_entry(png_image_read_control *display,
       if (convert_to_Y != 0 || output_encoding == P_LINEAR)
       {
          red = convert_to_linear(display, red,
-               use_sBIT ? display->sBIT[0] : 8U);
+             use_sBIT ? display->sBIT[0] : 8U);
          green = convert_to_linear(display, green,
-               use_sBIT ? display->sBIT[1] : 8U);
+             use_sBIT ? display->sBIT[1] : 8U);
          blue = convert_to_linear(display, blue,
-               use_sBIT ? display->sBIT[2] : 8U);
+             use_sBIT ? display->sBIT[2] : 8U);
          alpha *= 257U;
          if (use_sBIT)
             alpha = update_for_sBIT(alpha, display->sBIT[3], 16U);
@@ -1772,11 +1719,11 @@ png_create_colormap_entry(png_image_read_control *display,
       else
       {
          red = convert_to_sRGB(display, red,
-               use_sBIT ? display->sBIT[0] : 8U);
+             use_sBIT ? display->sBIT[0] : 8U);
          green = convert_to_sRGB(display, green,
-               use_sBIT ? display->sBIT[1] : 8U);
+             use_sBIT ? display->sBIT[1] : 8U);
          blue = convert_to_sRGB(display, blue,
-               use_sBIT ? display->sBIT[2] : 8U);
+             use_sBIT ? display->sBIT[2] : 8U);
          if (use_sBIT)
             alpha = update_for_sBIT(alpha, display->sBIT[3], 8U);
          encoding = P_sRGB;
@@ -1885,7 +1832,7 @@ png_create_colormap_entry(png_image_read_control *display,
    {
 #  ifdef PNG_FORMAT_AFIRST_SUPPORTED
       const int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
-         (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
+          (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
 #  else
 #    define afirst 0
 #  endif
@@ -2062,7 +2009,7 @@ make_ga_colormap(png_image_read_control *display)
 
       for (g=0; g<6; ++g)
          png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51,
-            P_sRGB);
+             P_sRGB);
    }
 
    return i;
@@ -2086,7 +2033,7 @@ make_rgb_colormap(png_image_read_control *display)
 
          for (b=0; b<6; ++b)
             png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255,
-               P_sRGB);
+                P_sRGB);
       }
    }
 
@@ -2139,7 +2086,7 @@ png_image_read_colormap(png_voidp argument)
 
       else if (display->background == NULL /* no way to remove it */)
          png_error(png_ptr,
-            "a background color must be supplied to remove alpha/transparency");
+             "background color must be supplied to remove alpha/transparency");
 
       /* Get a copy of the background color (this avoids repeating the checks
        * below.)  The encoding is 8-bit sRGB or 16-bit linear, depending on the
@@ -2239,7 +2186,7 @@ png_image_read_colormap(png_voidp argument)
                 */
                if (i != trans)
                   png_create_colormap_entry(display, i, val, val, val, 255,
-                     P_FILE/*8-bit with file gamma*/);
+                      P_FILE/*8-bit with file gamma*/);
 
                /* Else this entry is transparent.  The colors don't matter if
                 * there is an alpha channel (back_alpha == 0), but it does no
@@ -2254,10 +2201,10 @@ png_image_read_colormap(png_voidp argument)
 #ifdef __COVERITY__
                   /* Coverity says back_r|g|b might be 16-bit values */
                   png_affirmpp(png_ptr, back_r < 256 && back_g < 256 &&
-                     back_b < 256);
+                      back_b < 256);
 #endif
                   png_create_colormap_entry(display, i, back_r, back_g, back_b,
-                     back_alpha, output_encoding);
+                      back_alpha, output_encoding);
                }
             }
 
@@ -2323,7 +2270,7 @@ png_image_read_colormap(png_voidp argument)
                          * matches.
                          */
                         png_create_colormap_entry(display, gray, back_g, back_g,
-                           back_g, 65535, P_LINEAR);
+                            back_g, 65535, P_LINEAR);
                      }
 
                      /* The background passed to libpng, however, must be the
@@ -2331,15 +2278,15 @@ png_image_read_colormap(png_voidp argument)
                       */
                      c.index = 0; /*unused*/
                      c.gray = c.red = c.green = c.blue =
-                        png_check_u16(png_ptr, gray);
+                         png_check_u16(png_ptr, gray);
 
                      /* NOTE: does this work without expanding tRNS to alpha?
                       * It should be the color->gray case below apparently
                       * doesn't.
                       */
                      png_set_background_fixed(png_ptr, &c,
-                        PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
-                        0/*gamma: not used*/);
+                         PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                         0/*gamma: not used*/);
 
                      output_processing = PNG_CMAP_NONE;
                      break;
@@ -2371,7 +2318,7 @@ png_image_read_colormap(png_voidp argument)
                    back_b < 256);
 #endif
                png_create_colormap_entry(display, 254, back_r, back_g, back_b,
-                  back_alpha, output_encoding);
+                   back_alpha, output_encoding);
             }
 
             else
@@ -2439,7 +2386,7 @@ png_image_read_colormap(png_voidp argument)
 
                   /* And make sure the corresponding palette entry matches. */
                   png_create_colormap_entry(display, gray, back_g, back_g,
-                     back_g, 65535, P_LINEAR);
+                      back_g, 65535, P_LINEAR);
                }
 
                /* The background passed to libpng, however, must be the sRGB
@@ -2449,8 +2396,8 @@ png_image_read_colormap(png_voidp argument)
                c.gray = c.red = c.green = c.blue = png_check_u16(png_ptr, gray);
 
                png_set_background_fixed(png_ptr, &c,
-                  PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
-                  0/*gamma: not used*/);
+                   PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                   0/*gamma: not used*/);
 
                output_processing = PNG_CMAP_NONE;
             }
@@ -2470,7 +2417,7 @@ png_image_read_colormap(png_voidp argument)
                {
                   png_uint_32 gray = (i * 256 + 115) / 231;
                   png_create_colormap_entry(display, i++, gray, gray, gray,
-                     255, P_sRGB);
+                      255, P_sRGB);
                }
 
                /* NOTE: this preserves the full precision of the application
@@ -2548,7 +2495,7 @@ png_image_read_colormap(png_voidp argument)
              * png_set_tRNS_to_alpha before png_set_background_fixed.
              */
             png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1,
-               -1);
+                -1);
             data_encoding = P_sRGB;
 
             /* The output will now be one or two 8-bit gray or gray+alpha
@@ -2656,8 +2603,8 @@ png_image_read_colormap(png_voidp argument)
                    */
                   expand_tRNS = 1;
                   png_set_background_fixed(png_ptr, &c,
-                     PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
-                     0/*gamma: not used*/);
+                      PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                      0/*gamma: not used*/);
                }
 
                output_processing = PNG_CMAP_NONE;
@@ -2691,7 +2638,7 @@ png_image_read_colormap(png_voidp argument)
 
                   /* Add a transparent entry. */
                   png_create_colormap_entry(display, cmap_entries, 255, 255,
-                     255, 0, P_sRGB);
+                      255, 0, P_sRGB);
 
                   /* This is stored as the background index for the processing
                    * algorithm.
@@ -2712,7 +2659,7 @@ png_image_read_colormap(png_voidp argument)
                          */
                         for (b=0; b<256; b = (b << 1) | 0x7f)
                            png_create_colormap_entry(display, cmap_entries++,
-                              r, g, b, 128, P_sRGB);
+                               r, g, b, 128, P_sRGB);
                      }
                   }
 
@@ -2739,7 +2686,7 @@ png_image_read_colormap(png_voidp argument)
                   cmap_entries = make_rgb_colormap(display);
 
                   png_create_colormap_entry(display, cmap_entries, back_r,
-                        back_g, back_b, 0/*unused*/, output_encoding);
+                      back_g, back_b, 0/*unused*/, output_encoding);
 
                   if (output_encoding == P_LINEAR)
                   {
@@ -2761,9 +2708,9 @@ png_image_read_colormap(png_voidp argument)
                    * index.
                    */
                   if (memcmp((png_const_bytep)display->colormap +
-                        sample_size * cmap_entries,
-                     (png_const_bytep)display->colormap +
-                        sample_size * PNG_RGB_INDEX(r,g,b),
+                      sample_size * cmap_entries,
+                      (png_const_bytep)display->colormap +
+                          sample_size * PNG_RGB_INDEX(r,g,b),
                      sample_size) != 0)
                   {
                      /* The background color must be added. */
@@ -2805,8 +2752,8 @@ png_image_read_colormap(png_voidp argument)
                      c.blue = png_check_u16(png_ptr, back_b);
 
                      png_set_background_fixed(png_ptr, &c,
-                        PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
-                        0/*gamma: not used*/);
+                         PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                         0/*gamma: not used*/);
 
                      output_processing = PNG_CMAP_RGB;
                   }
@@ -2858,7 +2805,7 @@ png_image_read_colormap(png_voidp argument)
                {
                   if (trans[i] == 0)
                      png_create_colormap_entry(display, i, back_r, back_g,
-                        back_b, 0, output_encoding);
+                         back_b, 0, output_encoding);
 
                   else
                   {
@@ -2983,7 +2930,7 @@ static int
 png_image_read_and_map(png_voidp argument)
 {
    png_image_read_control *display = png_voidcast(png_image_read_control*,
-      argument);
+       argument);
    png_imagep image = display->image;
    png_structrp png_ptr = image->opaque->png_ptr;
    int passes;
@@ -3120,7 +3067,7 @@ png_image_read_and_map(png_voidp argument)
 
                      if (alpha >= 196)
                         *outrow = PNG_RGB_INDEX(inrow[0], inrow[1],
-                           inrow[2]);
+                            inrow[2]);
 
                      else if (alpha < 64)
                         *outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND;
@@ -3172,7 +3119,7 @@ static int
 png_image_read_colormapped(png_voidp argument)
 {
    png_image_read_control *display = png_voidcast(png_image_read_control*,
-      argument);
+       argument);
    png_imagep image = display->image;
    png_controlp control = image->opaque;
    png_structrp png_ptr = control->png_ptr;
@@ -3310,7 +3257,7 @@ static int
 png_image_read_composite(png_voidp argument)
 {
    png_image_read_control *display = png_voidcast(png_image_read_control*,
-      argument);
+       argument);
    png_imagep image = display->image;
    png_structrp png_ptr = image->opaque->png_ptr;
    int passes;
@@ -3438,7 +3385,7 @@ static int
 png_image_read_background(png_voidp argument)
 {
    png_image_read_control *display = png_voidcast(png_image_read_control*,
-      argument);
+       argument);
    png_imagep image = display->image;
    png_structrp png_ptr = image->opaque->png_ptr;
    png_inforp info_ptr = image->opaque->info_ptr;
@@ -3497,8 +3444,7 @@ png_image_read_background(png_voidp argument)
 
             for (pass = 0; pass < passes; ++pass)
             {
-               png_bytep        row = png_voidcast(png_bytep,
-                                                   display->first_row);
+               png_bytep row = png_voidcast(png_bytep, display->first_row);
                unsigned int     startx, stepx, stepy;
                png_uint_32      y;
 
@@ -3526,7 +3472,7 @@ png_image_read_background(png_voidp argument)
                   for (; y<height; y += stepy)
                   {
                      png_bytep inrow = png_voidcast(png_bytep,
-                        display->local_row);
+                         display->local_row);
                      png_bytep outrow = first_row + y * step_row;
                      png_const_bytep end_row = outrow + width;
 
@@ -3572,7 +3518,7 @@ png_image_read_background(png_voidp argument)
                   for (; y<height; y += stepy)
                   {
                      png_bytep inrow = png_voidcast(png_bytep,
-                        display->local_row);
+                         display->local_row);
                      png_bytep outrow = first_row + y * step_row;
                      png_const_bytep end_row = outrow + width;
 
@@ -3620,7 +3566,7 @@ png_image_read_background(png_voidp argument)
           */
          {
             png_uint_16p first_row = png_voidcast(png_uint_16p,
-               display->first_row);
+                display->first_row);
             /* The division by two is safe because the caller passed in a
              * stride which was multiplied by 2 (below) to get row_bytes.
              */
@@ -3670,7 +3616,7 @@ png_image_read_background(png_voidp argument)
 
                   /* Read the row, which is packed: */
                   png_read_row(png_ptr, png_voidcast(png_bytep,
-                     display->local_row), NULL);
+                      display->local_row), NULL);
                   inrow = png_voidcast(png_const_uint_16p, display->local_row);
 
                   /* Now do the pre-multiplication on each pixel in this row.
@@ -3715,7 +3661,7 @@ static int
 png_image_read_direct(png_voidp argument)
 {
    png_image_read_control *display = png_voidcast(png_image_read_control*,
-      argument);
+       argument);
    png_imagep image = display->image;
    png_structrp png_ptr = image->opaque->png_ptr;
    png_inforp info_ptr = image->opaque->info_ptr;
@@ -3766,7 +3712,7 @@ png_image_read_direct(png_voidp argument)
                do_local_background = 1/*maybe*/;
 
             png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE,
-               PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT);
+                PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT);
          }
 
          change &= PNG_BIC_MASK(PNG_FORMAT_FLAG_COLOR);
@@ -3885,8 +3831,8 @@ png_image_read_direct(png_voidp argument)
                 * pixels.
                 */
                png_set_background_fixed(png_ptr, &c,
-                  PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
-                  0/*gamma: not used*/);
+                   PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                   0/*gamma: not used*/);
             }
 
             else /* compose on row: implemented below. */
@@ -4128,7 +4074,7 @@ png_image_read_direct(png_voidp argument)
 
 int PNGAPI
 png_image_finish_read(png_imagep image, png_const_colorp background,
-   void *buffer, ptrdiff_t row_stride, void *colormap)
+    void *buffer, ptrdiff_t row_stride, void *colormap)
 {
    if (image != NULL && image->version == PNG_IMAGE_VERSION)
    {
@@ -4159,11 +4105,21 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
 
          if (image->opaque != NULL && buffer != NULL && check >= png_row_stride)
          {
-            /* Now check for overflow of the image buffer calculation; check for
-             * (size_t) overflow here.  This detects issues with the
-             * PNG_IMAGE_BUFFER_SIZE macro.
+            /* Now check for overflow of the image buffer calculation; this
+             * limits the whole image size to PNG_SIZE_MAX bytes.
+             *
+             * The PNG_IMAGE_BUFFER_SIZE macro is:
+             *
+             *    (PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)*height*(row_stride))
+             *
+             * We have no way of guaranteeing that the application used the
+             * correct type for 'row_stride' if it used the macro, so this is
+             * technically not completely safe, but this is the case throughout
+             * libpng; the app is responsible for making sure the calcualtion of
+             * buffer sizes does not overflow.
              */
-            if (image->height <= PNG_SIZE_MAX/png_row_stride)
+            if (image->height <= PNG_SIZE_MAX /
+                  PNG_IMAGE_PIXEL_COMPONENT_SIZE(image->format) / check)
             {
                if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 ||
                   (image->colormap_entries > 0 && colormap != NULL))
@@ -4183,15 +4139,16 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
                    * all the setup has already been done.
                    */
                   if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0)
-                     result = png_safe_execute(image,
-                                    png_image_read_colormap, &display) &&
-                              png_safe_execute(image,
-                                    png_image_read_colormapped, &display);
+                     result =
+                         png_safe_execute(image,
+                             png_image_read_colormap, &display) &&
+                             png_safe_execute(image,
+                             png_image_read_colormapped, &display);
 
                   else
                      result =
                         png_safe_execute(image,
-                              png_image_read_direct, &display);
+                            png_image_read_direct, &display);
 
                   png_image_free(image);
                   return result;
@@ -4199,27 +4156,27 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
 
                else
                   return png_image_error(image,
-                     "png_image_finish_read[color-map]: no color-map");
+                      "png_image_finish_read[color-map]: no color-map");
             }
 
             else
                return png_image_error(image,
-                  "png_image_finish_read: image too large");
+                   "png_image_finish_read: image too large");
          }
 
          else
             return png_image_error(image,
-               "png_image_finish_read: invalid argument");
+                "png_image_finish_read: invalid argument");
       }
 
       else
          return png_image_error(image,
-            "png_image_finish_read: row_stride too large");
+             "png_image_finish_read: row_stride too large");
    }
 
    else if (image != NULL)
       return png_image_error(image,
-         "png_image_finish_read: damaged PNG_IMAGE_VERSION");
+          "png_image_finish_read: damaged PNG_IMAGE_VERSION");
 
    return 0;
 }

pngrio.c

@@ -19,7 +19,7 @@
  */
 
 #include "pngpriv.h"
-#define PNG_SRC_FILE PNG_SRC_FILE_rio
+#define PNG_SRC_FILE PNG_SRC_FILE_pngrio
 
 #ifdef PNG_READ_SUPPORTED
 
@@ -34,6 +34,11 @@ png_read_data(png_structrp png_ptr, png_voidp data, png_size_t length)
 {
    png_debug1(4, "reading %d bytes", (int)length);
 
+   /* This was guaranteed by prior versions of libpng, so app callbacks may
+    * assume it even though it isn't documented to be the case.
+    */
+   debug(length > 0U);
+
    if (png_ptr->rw_data_fn != NULL)
       png_ptr->rw_data_fn(png_ptr, png_voidcast(png_bytep,data), length);
 
@@ -86,7 +91,7 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
  */
 void PNGAPI
 png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
-   png_rw_ptr read_data_fn)
+    png_rw_ptr read_data_fn)
 {
    if (png_ptr == NULL)
       return;

pngrtran.c

@@ -3434,9 +3434,29 @@ png_init_gamma(png_transformp *transform, png_transform_controlp tc)
    }
 }
 
+#if !PNG_RELEASE_BUILD
+int /* PRIVATE(debug only) */
+png_gamma_check(png_const_structrp png_ptr, png_const_transform_controlp tc)
+   /* Debugging only routine to repeat the test used above to determine if the
+    * gamma was insignificant.
+    *
+    * NOTE: JB20160723: This may still be incorrect in a complicated transform
+    * pipeline because it uses 'tc_sBIT' for the end of the pipeline whereas the
+    * init above happens earlier.  I don't think this matters because the test
+    * is only invoked if the gamma transform is eliminated or if there is a bug
+    * and in the former case the sBIT values should remain unchanged.
+    */
+{
+   png_fixed_point dummy;
+
+   return png_gamma_equal(png_ptr, png_ptr->row_gamma, tc->gamma, &dummy,
+                          tc_sBIT(tc));
+}
+#endif /* !RELEASE_BUILD */
+
 static png_fixed_point
 translate_gamma_flags(png_const_structrp png_ptr, png_fixed_point gamma,
-   int is_screen)
+    int is_screen)
    /* If 'is_screen' is set this returns the inverse of the supplied value; i.e.
     * this routine always returns an encoding value.
     */
@@ -3511,7 +3531,7 @@ add_gamma_transform(png_structrp png_ptr, unsigned int order,
 
 void PNGFAPI
 png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma,
-   png_fixed_point file_gamma)
+    png_fixed_point file_gamma)
 {
    png_debug(1, "in png_set_gamma_fixed");
 
@@ -3566,7 +3586,7 @@ void PNGAPI
 png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma)
 {
    png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
-      convert_gamma_value(png_ptr, file_gamma));
+       convert_gamma_value(png_ptr, file_gamma));
 }
 #endif /* FLOATING_POINT */
 #endif /* READ_GAMMA */
@@ -4044,7 +4064,7 @@ png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
 
 void PNGAPI
 png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red,
-   double green)
+    double green)
 {
    png_set_rgb_to_gray_fixed(png_ptr, error_action,
       png_fixed(png_ptr, red, "rgb to gray red coefficient"),
@@ -5490,7 +5510,7 @@ png_set_background(png_structrp png_ptr,
 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
 void PNGFAPI
 png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
-   png_fixed_point output_gamma)
+    png_fixed_point output_gamma)
 {
    if (png_ptr != NULL)
    {
@@ -5603,7 +5623,7 @@ void PNGAPI
 png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma)
 {
    png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
-      output_gamma));
+       output_gamma));
 }
 #endif /* FLOATING_POINT */
 #endif /* READ_ALPHA_MODE */
@@ -5885,26 +5905,31 @@ typedef struct
 }  png_cache_params, *png_cache_paramsp;
 
 static void
-init_caching(png_structp png_ptr, png_cache_paramsp cp)
-   /* Given an already initialized cp->tend turn on caching if appropriate. */
+init_caching(png_structp png_ptr, png_transform_controlp tend)
+   /* Given an already initialized tend turn on caching if appropriate. */
 {
    /* Handle the colormap case, where a cache is always required: */
-   if (cp->tend.format & PNG_FORMAT_FLAG_COLORMAP)
+   if (tend->format & PNG_FORMAT_FLAG_COLORMAP)
    {
       /* This turns starts the palette caching with the next transform: */
-      cp->tend.palette = cp->tend.caching = 1U;
-      cp->tend.transparent_alpha = png_ptr->transparent_palette;
-      cp->tend.format = PNG_FORMAT_FLAG_COLOR;
+      tend->palette = tend->caching = 1U;
 #     ifdef PNG_READ_tRNS_SUPPORTED
-         if (png_ptr->num_trans > 0 && !(cp->tend.invalid_info & PNG_INFO_tRNS))
+         tend->transparent_alpha = png_ptr->transparent_palette;
+#     else /* !READ_tRNS */
+         tend->transparent_alpha = 0;
+         PNG_UNUSED(png_ptr)
+#     endif /* !READ_tRNS */
+      tend->format = PNG_FORMAT_FLAG_COLOR;
+#     ifdef PNG_READ_tRNS_SUPPORTED
+         if (png_ptr->num_trans > 0 && !(tend->invalid_info & PNG_INFO_tRNS))
          {
-            cp->tend.format |= PNG_FORMAT_FLAG_ALPHA;
+            tend->format |= PNG_FORMAT_FLAG_ALPHA;
          }
 #     endif /* READ_tRNS */
-      cp->tend.bit_depth = 8U;
+      tend->bit_depth = 8U;
    }
 
-   else if (PNG_TC_PIXEL_DEPTH(cp->tend) <= 8)
+   else if (PNG_TC_PIXEL_DEPTH(*tend) <= 8)
    {
       /* Cacheable pixel transforms; the pixel is less than 8 bits in size so
        * the cache makes sense.
@@ -5912,7 +5937,7 @@ init_caching(png_structp png_ptr, png_cache_paramsp cp)
        * TODO: check the cost estimate and the image size to avoid expensive
        * caches of very small images.
        */
-      cp->tend.caching = 1U;
+      tend->caching = 1U;
    }
 
    /* TODO: handle handle 8-bit GA/RGB/RGBA */
@@ -6019,7 +6044,6 @@ update_palette(png_structp png_ptr, png_cache_paramsp cp,
     * list, so:
     */
    affirm((cp->tstart.format & PNG_FORMAT_FLAG_COLORMAP) != 0); /* required */
-   debug(cp->start == &png_ptr->transform_list); /* should be harmless */
 
    /* Run the whole of the given list on the palette data.  PNG_TC_INIT_FINAL
     * has already been run; this is a full run (with init == 0).
@@ -6029,7 +6053,7 @@ update_palette(png_structp png_ptr, png_cache_paramsp cp,
       only_deb(png_transform_control orig = cp->tend;)
 
       cp->tend = cp->tstart;
-      init_caching(png_ptr, cp);
+      init_caching(png_ptr, &cp->tend);
       /* And set up tend to actually work out the palette: */
       cp->tend.init = 0U;
       cp->tend.width = setup_palette_cache(png_ptr, cache.b8);
@@ -6296,7 +6320,7 @@ make_cache(png_structp png_ptr, png_cache_paramsp cp, unsigned int max_depth)
     */
    save_cp_channel_data(&save, &cp->tend);
    cp->tend = cp->tstart;
-   init_caching(png_ptr, cp);
+   init_caching(png_ptr, &cp->tend);
    /* And set tend to work out the result of transforming each possible pixel
     * value:
     */
@@ -6589,7 +6613,7 @@ png_read_init_transform_mech(png_structp png_ptr, png_transform_controlp tc)
     */
 {
    png_transformp *list = &png_ptr->transform_list;
-   unsigned int max_depth;
+   unsigned int max_depth, cache_start_depth;
    png_cache_params cp;
 
    /* PNG color-mapped data must be handled here so that the palette is updated
@@ -6608,8 +6632,7 @@ png_read_init_transform_mech(png_structp png_ptr, png_transform_controlp tc)
 #  endif /* READ_tRNS */
    cp.end = cp.start = list;
    cp.tend = cp.tstart = *tc;
-   init_caching(png_ptr, &cp);
-   max_depth = PNG_TC_PIXEL_DEPTH(cp.tend);
+   max_depth = cache_start_depth = PNG_TC_PIXEL_DEPTH(cp.tend);
 
    while (*cp.end != NULL)
    {
@@ -6619,6 +6642,22 @@ png_read_init_transform_mech(png_structp png_ptr, png_transform_controlp tc)
       if (tr->order >= PNG_TR_USER)
          break;
 
+      /* If caching is not on and this transform is after PNG_TR_START_CACHE
+       * try to turn it on.
+       */
+      if (tr->order > PNG_TR_START_CACHE && !cp.tend.caching)
+      {
+         cp.start = cp.end;
+         cp.tstart = cp.tend;
+         init_caching(png_ptr, &cp.tend);
+
+         if (cp.tend.caching)
+         {
+            cache_start_depth = max_depth;
+            max_depth = PNG_TC_PIXEL_DEPTH(cp.tend);
+         }
+      }
+
       /* If the 'palette' flag is set and the next transform has order
        * PNG_TR_ENCODING or later cache the results so far and continue with the
        * original palette data (cp.tstart).
@@ -6630,6 +6669,8 @@ png_read_init_transform_mech(png_structp png_ptr, png_transform_controlp tc)
          /* The cache handling function must maintain cp.end; */
          affirm(tr == *cp.end);
          max_depth = PNG_TC_PIXEL_DEPTH(cp.tend);
+         if (max_depth < cache_start_depth)
+            max_depth = cache_start_depth;
       }
 
       /* Now run the transform list entry: */
@@ -6664,6 +6705,8 @@ png_read_init_transform_mech(png_structp png_ptr, png_transform_controlp tc)
       handle_cache(png_ptr, &cp, max_depth);
       affirm(tr == *cp.end);
       max_depth = PNG_TC_PIXEL_DEPTH(cp.tend);
+      if (max_depth < cache_start_depth)
+         max_depth = cache_start_depth;
    }
 
    /* At the end run the init on the user transform: */

pngset.c

@@ -105,14 +105,14 @@ png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
     double green_x, double green_y, double blue_x, double blue_y)
 {
    png_set_cHRM_fixed(png_ptr, info_ptr,
-      png_fixed(png_ptr, white_x, "cHRM White X"),
-      png_fixed(png_ptr, white_y, "cHRM White Y"),
-      png_fixed(png_ptr, red_x, "cHRM Red X"),
-      png_fixed(png_ptr, red_y, "cHRM Red Y"),
-      png_fixed(png_ptr, green_x, "cHRM Green X"),
-      png_fixed(png_ptr, green_y, "cHRM Green Y"),
-      png_fixed(png_ptr, blue_x, "cHRM Blue X"),
-      png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
+       png_fixed(png_ptr, white_x, "cHRM White X"),
+       png_fixed(png_ptr, white_y, "cHRM White Y"),
+       png_fixed(png_ptr, red_x, "cHRM Red X"),
+       png_fixed(png_ptr, red_y, "cHRM Red Y"),
+       png_fixed(png_ptr, green_x, "cHRM Green X"),
+       png_fixed(png_ptr, green_y, "cHRM Green Y"),
+       png_fixed(png_ptr, blue_x, "cHRM Blue X"),
+       png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
 }
 
 void PNGAPI
@@ -121,15 +121,15 @@ png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X,
     double blue_X, double blue_Y, double blue_Z)
 {
    png_set_cHRM_XYZ_fixed(png_ptr, info_ptr,
-      png_fixed(png_ptr, red_X, "cHRM Red X"),
-      png_fixed(png_ptr, red_Y, "cHRM Red Y"),
-      png_fixed(png_ptr, red_Z, "cHRM Red Z"),
-      png_fixed(png_ptr, green_X, "cHRM Green X"),
-      png_fixed(png_ptr, green_Y, "cHRM Green Y"),
-      png_fixed(png_ptr, green_Z, "cHRM Green Z"),
-      png_fixed(png_ptr, blue_X, "cHRM Blue X"),
-      png_fixed(png_ptr, blue_Y, "cHRM Blue Y"),
-      png_fixed(png_ptr, blue_Z, "cHRM Blue Z"));
+       png_fixed(png_ptr, red_X, "cHRM Red X"),
+       png_fixed(png_ptr, red_Y, "cHRM Red Y"),
+       png_fixed(png_ptr, red_Z, "cHRM Red Z"),
+       png_fixed(png_ptr, green_X, "cHRM Green X"),
+       png_fixed(png_ptr, green_Y, "cHRM Green Y"),
+       png_fixed(png_ptr, green_Z, "cHRM Green Z"),
+       png_fixed(png_ptr, blue_X, "cHRM Blue X"),
+       png_fixed(png_ptr, blue_Y, "cHRM Blue Y"),
+       png_fixed(png_ptr, blue_Z, "cHRM Blue Z"));
 }
 #  endif /* FLOATING_POINT */
 
@@ -304,10 +304,10 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
 
    length = strlen(units) + 1;
    png_debug1(3, "allocating units for info (%lu bytes)",
-     (unsigned long)length);
+       (unsigned long)length);
 
    info_ptr->pcal_units = png_voidcast(png_charp,
-      png_malloc_warn(png_ptr, length));
+       png_malloc_warn(png_ptr, length));
 
    if (info_ptr->pcal_units == NULL)
    {
@@ -386,7 +386,7 @@ png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
    png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);
 
    info_ptr->scal_s_width = png_voidcast(png_charp,
-      png_malloc_warn(png_ptr, lengthw));
+       png_malloc_warn(png_ptr, lengthw));
 
    if (info_ptr->scal_s_width == NULL)
    {
@@ -402,7 +402,7 @@ png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
    png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);
 
    info_ptr->scal_s_height = png_voidcast(png_charp,
-      png_malloc_warn(png_ptr, lengthh));
+       png_malloc_warn(png_ptr, lengthh));
 
    if (info_ptr->scal_s_height == NULL)
    {
@@ -442,9 +442,9 @@ png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
       char sheight[PNG_sCAL_MAX_DIGITS+1];
 
       png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width,
-         PNG_sCAL_PRECISION);
+          PNG_sCAL_PRECISION);
       png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height,
-         PNG_sCAL_PRECISION);
+          PNG_sCAL_PRECISION);
 
       png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
    }
@@ -539,12 +539,30 @@ png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
     * of num_palette entries, in case of an invalid PNG file or incorrect
     * call to png_set_PLTE() with too-large sample values.
     */
-   info_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
+   info_ptr->palette = png_voidcast(png_colorp, png_malloc(png_ptr,
        PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));
 
    if (num_palette > 0)
       memcpy(info_ptr->palette, palette, num_palette * (sizeof (png_color)));
 
+   /* Set the remainder of the palette entries to something recognizable; the
+    * code used to leave them set to 0, which made seeing palette index errors
+    * difficult.
+    */
+   if (num_palette < PNG_MAX_PALETTE_LENGTH)
+   {
+      int i;
+      png_color c;
+
+      memset(&c, 0x42, sizeof c); /* fill in any padding */
+      c.red = 0xbe;
+      c.green = 0xad;
+      c.blue = 0xed;   /* Visible in memory as 'beaded' */
+
+      for (i=num_palette; i<PNG_MAX_PALETTE_LENGTH; ++i)
+         info_ptr->palette[i] = c;
+   }
+
    info_ptr->num_palette = png_check_bits(png_ptr, num_palette, 9);
    info_ptr->free_me |= PNG_FREE_PLTE;
    info_ptr->valid |= PNG_INFO_PLTE;
@@ -626,7 +644,7 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
     */
    {
       int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name,
-         proflen, profile, (info_ptr->format & PNG_FORMAT_FLAG_COLOR) != 0);
+          proflen, profile, (info_ptr->format & PNG_FORMAT_FLAG_COLOR) != 0);
 
       png_colorspace_sync_info(png_ptr, info_ptr);
 
@@ -636,7 +654,7 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
 
       /* But do write the gAMA and cHRM chunks from the profile. */
       info_ptr->colorspace.flags |=
-         PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
+          PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
    }
 
    length = strlen(name)+1;
@@ -651,7 +669,7 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
 
    memcpy(new_iccp_name, name, length);
    new_iccp_profile = png_voidcast(png_bytep,
-      png_malloc_warn(png_ptr, proflen));
+       png_malloc_warn(png_ptr, proflen));
 
    if (new_iccp_profile == NULL)
    {
@@ -801,14 +819,14 @@ png_set_text_2(png_structrp png_ptr, png_inforp info_ptr,
           * the overflow checks.
           */
          new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
-            info_ptr->text, old_num_text, max_text-old_num_text,
-            sizeof *new_text));
+             info_ptr->text, old_num_text, max_text-old_num_text,
+             sizeof *new_text));
       }
 
       if (new_text == NULL)
       {
          png_chunk_report(png_ptr, "too many text chunks",
-            PNG_CHUNK_WRITE_ERROR);
+             PNG_CHUNK_WRITE_ERROR);
 
          return 1;
       }
@@ -836,7 +854,7 @@ png_set_text_2(png_structrp png_ptr, png_inforp info_ptr,
           text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
       {
          png_chunk_report(png_ptr, "text compression mode is out of range",
-            PNG_CHUNK_WRITE_ERROR);
+             PNG_CHUNK_WRITE_ERROR);
          continue;
       }
 
@@ -868,7 +886,7 @@ png_set_text_2(png_structrp png_ptr, png_inforp info_ptr,
 #  else /* iTXt */
       {
          png_chunk_report(png_ptr, "iTXt chunk not supported",
-            PNG_CHUNK_WRITE_ERROR);
+             PNG_CHUNK_WRITE_ERROR);
          continue;
       }
 #  endif
@@ -903,7 +921,7 @@ png_set_text_2(png_structrp png_ptr, png_inforp info_ptr,
       if (textp->key == NULL)
       {
          png_chunk_report(png_ptr, "text chunk: out of memory",
-               PNG_CHUNK_WRITE_ERROR);
+             PNG_CHUNK_WRITE_ERROR);
 
          return 1;
       }
@@ -1013,7 +1031,7 @@ png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
 
    if ((info_ptr->format & PNG_FORMAT_FLAG_ALPHA) != 0)
       png_chunk_report(png_ptr,
-         "png_set_tRNS: invalid on PNG with alpha channel", PNG_CHUNK_ERROR);
+          "png_set_tRNS: invalid on PNG with alpha channel", PNG_CHUNK_ERROR);
 
    else if ((info_ptr->format & PNG_FORMAT_FLAG_COLORMAP) != 0)
    {
@@ -1039,7 +1057,7 @@ png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
       if (num_trans > max_num)
       {
          png_chunk_report(png_ptr, "png_set_tRNS: num_trans too large",
-            PNG_CHUNK_ERROR);
+             PNG_CHUNK_ERROR);
          /* If control returns simply limit it; the behavior prior to 1.7 was to
           * issue a warning and skip the palette in png_write_tRNS.
           */
@@ -1056,11 +1074,11 @@ png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
           * indices.
           */
          info_ptr->trans_alpha = png_voidcast(png_bytep, png_malloc(png_ptr,
-            PNG_MAX_PALETTE_LENGTH));
+             PNG_MAX_PALETTE_LENGTH));
          info_ptr->free_me |= PNG_FREE_TRNS;
 
          memcpy(info_ptr->trans_alpha, trans_alpha,
-            (unsigned)/*SAFE*/num_trans);
+             (unsigned)/*SAFE*/num_trans);
          info_ptr->valid |= PNG_INFO_tRNS;
          info_ptr->num_trans = png_check_bits(png_ptr, num_trans, 9);
       }
@@ -1091,8 +1109,8 @@ png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
 
          else
             png_chunk_report(png_ptr,
-               "tRNS chunk has out-of-range samples for bit_depth",
-               PNG_CHUNK_ERROR);
+                "tRNS chunk has out-of-range samples for bit_depth",
+                PNG_CHUNK_ERROR);
       }
    }
 }
@@ -1120,8 +1138,8 @@ png_set_sPLT(png_structrp png_ptr,
     * overflows.  Notice that the parameters are (int) and (size_t)
     */
    np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr,
-      info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
-      sizeof *np));
+       info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
+       sizeof *np));
 
    if (np == NULL)
    {
@@ -1182,7 +1200,7 @@ png_set_sPLT(png_structrp png_ptr,
        * checked it when doing the allocation.
        */
       memcpy(np->entries, entries->entries,
-         entries->nentries * sizeof (png_sPLT_entry));
+          entries->nentries * sizeof (png_sPLT_entry));
 
       /* Note that 'continue' skips the advance of the out pointer and out
        * count, so an invalid entry is not added.
@@ -1190,8 +1208,9 @@ png_set_sPLT(png_structrp png_ptr,
       info_ptr->valid |= PNG_INFO_sPLT;
       ++(info_ptr->splt_palettes_num);
       ++np;
+      ++entries;
    }
-   while (++entries, --nentries);
+   while (--nentries);
 
    if (nentries > 0)
       png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
@@ -1212,10 +1231,10 @@ check_location(png_const_structrp png_ptr, int location)
    {
       /* Write struct, so unknown chunks come from the app */
       png_app_warning(png_ptr,
-         "png_set_unknown_chunks now expects a valid location");
+          "png_set_unknown_chunks now expects a valid location");
       /* Use the old behavior */
       location = png_check_byte(png_ptr, png_ptr->mode &
-         (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
+          (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
    }
 
    /* This need not be an internal error - if the app calls
@@ -1238,7 +1257,7 @@ check_location(png_const_structrp png_ptr, int location)
 
 void PNGAPI
 png_set_unknown_chunks(png_structrp png_ptr,
-   png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
+    png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
 {
    png_unknown_chunkp np;
 
@@ -1308,12 +1327,12 @@ png_set_unknown_chunks(png_structrp png_ptr,
       else
       {
          np->data = png_voidcast(png_bytep,
-            png_malloc_base(png_ptr, unknowns->size));
+             png_malloc_base(png_ptr, unknowns->size));
 
          if (np->data == NULL)
          {
             png_chunk_report(png_ptr, "unknown chunk: out of memory",
-               PNG_CHUNK_ERROR);
+                PNG_CHUNK_ERROR);
             /* But just skip storing the unknown chunk */
             continue;
          }
@@ -1518,7 +1537,7 @@ png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
       for (i=0; i<num_chunks; ++i)
       {
          old_num_chunks = add_one_chunk(png_ptr, new_list, old_num_chunks,
-            chunk_list+5*i, keep);
+             chunk_list+5*i, keep);
       }
 
       /* Now remove any spurious 'default' entries. */
@@ -1606,7 +1625,7 @@ png_set_compression_buffer_size(png_structrp png_ptr, png_alloc_size_t size)
       png_error(png_ptr, "invalid compression buffer size");
 
 #  if (defined PNG_SEQUENTIAL_READ_SUPPORTED) || defined PNG_WRITE_SUPPORTED
-      png_ptr->IDAT_size = (png_uint_32)/*SAFE*/size;
+   png_ptr->IDAT_size = (png_uint_32)/*SAFE*/size;
 #  endif /* SEQUENTIAL_READ || WRITE */
 }
 
@@ -1652,27 +1671,4 @@ png_set_chunk_malloc_max (png_structrp png_ptr,
       png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
 }
 #endif /* ?SET_USER_LIMITS */
-
-
-#ifdef PNG_BENIGN_ERRORS_SUPPORTED
-void PNGAPI
-png_set_benign_errors(png_structrp png_ptr, int allowed)
-{
-   png_debug(1, "in png_set_benign_errors");
-
-   /* If allowed is 1, png_benign_error() is treated as a warning.
-    *
-    * If allowed is 0, png_benign_error() is treated as an error (which
-    * is the default behavior if png_set_benign_errors() is not called).
-    */
-
-   if (allowed != 0)
-      png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN |
-         PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN;
-
-   else
-      png_ptr->flags &= PNG_BIC_MASK(PNG_FLAG_BENIGN_ERRORS_WARN |
-         PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN);
-}
-#endif /* BENIGN_ERRORS */
 #endif /* READ || WRITE */

pngstruct.h

@@ -351,6 +351,15 @@ typedef struct png_transform /* Linked list of transform functions */
 }  png_transform;
 #endif /* TRANSFORM_MECH */
 
+/* Action to take on CRC errors (four values) */
+typedef enum
+{
+   crc_error_quit = PNG_CRC_ERROR_QUIT-1,
+   crc_warn_discard = PNG_CRC_WARN_DISCARD-1,
+   crc_warn_use = PNG_CRC_WARN_USE-1,
+   crc_quiet_use = PNG_CRC_QUIET_USE-1
+}  png_crc_action;
+
 struct png_struct_def
 {
    /* Rearranged in libpng 1.7 to attempt to lessen padding; in general
@@ -382,10 +391,11 @@ struct png_struct_def
    png_uint_32 width;          /* width of image in pixels */
    png_uint_32 height;         /* height of image in pixels */
    png_uint_32 chunk_name;     /* PNG_CHUNK() id of current chunk */
+#ifdef PNG_READ_SUPPORTED
    png_uint_32 chunk_length;   /* Length (possibly remaining) in said chunk. */
+#endif /* READ */
    png_uint_32 crc;            /* current chunk CRC value */
 
-   unsigned int flags;                  /* flags (should be bit fields) */
    unsigned int mode                :6; /* where we are in the PNG file */
    unsigned int read_struct         :1; /* this is a read (not write) struct */
    unsigned int num_palette         :9; /* number of color entries in palette */
@@ -393,13 +403,15 @@ struct png_struct_def
    unsigned int num_trans           :9; /* number of transparency values */
    unsigned int transparent_palette :1; /* if they are all 0 or 255 */
 #endif /* READ_tRNS */
-#ifdef PNG_GET_PALETTE_MAX_SUPPORTED
-   unsigned int palette_index_max :9; /* maximum palette index found in IDAT */
-#endif /* GET_PALETTE_MAX */
-#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-   unsigned int palette_index_check_disabled :1; /* defaults to 0, 'enabled' */
-   unsigned int palette_index_check_issued :1;   /* error message output */
-#endif /* CHECK_FOR_INVALID_INDEX */
+#ifdef PNG_PALETTE_MAX_SUPPORTED
+   unsigned int palette_index_max   :8; /* maximum palette index in IDAT */
+   unsigned int palette_index_check :2; /* one of the following: */
+#     define PNG_PALETTE_CHECK_DEFAULT 0U
+#     define PNG_PALETTE_CHECK_OFF     1U
+#     define PNG_PALETTE_CHECK_ON      2U
+   unsigned int palette_index_have_max     :1; /* max is being set */
+   unsigned int palette_index_check_issued :1; /* error message output */
+#endif /* PALETTE_MAX */
 #ifdef PNG_READ_tRNS_SUPPORTED
    png_color_16 trans_color;   /* transparent color for non-paletted files */
 #endif /* READ_tRNS */
@@ -410,18 +422,12 @@ struct png_struct_def
    /* Single byte values, typically used either to save space or to hold 1-byte
     * values from the PNG chunk specifications.
     */
-   png_byte compression_type; /* file compression type (always 0) */
    png_byte filter_method;    /* file filter type (only non-0 with MNG) */
    png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
    png_byte color_type;       /* color type of file */
    png_byte bit_depth;        /* bit depth of file */
    png_byte sig_bytes;        /* magic bytes read/written at start of file */
 
-   /* Options */
-#ifdef PNG_SET_OPTION_SUPPORTED
-   png_uint_32 options;       /* On/off state (up to 16 options) */
-#endif /* SET_OPTIONS */
-
 #ifdef PNG_READ_SUPPORTED
 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
    /* The png_struct colorspace structure is only required on read - on write it
@@ -444,7 +450,6 @@ struct png_struct_def
     */
 #ifdef PNG_READ_SUPPORTED
    png_bytep        row_buffer;          /* primary row buffer */
-#endif /* READ */
 #if (defined(PNG_PROGRESSIVE_READ_SUPPORTED) ||\
      defined(PNG_READ_INTERLACING_SUPPORTED)) &&\
     defined(PNG_TRANSFORM_MECH_SUPPORTED)
@@ -453,11 +458,11 @@ struct png_struct_def
                                           */
 #endif /* (PROGRESSIVE_READ || READ_INTERLACING) && TRANSFORM_MECH */
 
-#ifdef PNG_READ_SUPPORTED
    png_alloc_size_t row_bytes_read;   /* Total read in row */
 #endif /* READ */
 
    png_uint_32      row_number;       /* current row in pass */
+#ifdef PNG_READ_SUPPORTED
 #ifdef PNG_READ_GAMMA_SUPPORTED
    png_fixed_point  row_gamma;        /* Gamma of final output */
 #if 0 /* NYI */
@@ -482,23 +487,22 @@ struct png_struct_def
    unsigned int invalid_info;      /* PNG_INFO_* for invalidated chunks */
    unsigned int palette_updated:1; /* png_struct::palette changed */
 #endif /* READ_TRANSFORMS */
-#ifdef PNG_WRITE_SUPPORTED
-   unsigned int write_rows     :1; /* libpng has complete rows to write */
-#endif /* WRITE */
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
    unsigned int read_started   :1; /* at least one call to png_read_row */
 #endif /* SEQUENTIAL_READ */
-#if defined (PNG_READ_INTERLACING_SUPPORTED) ||\
-    defined (PNG_WRITE_INTERLACING_SUPPORTED)
-   unsigned int do_interlace   :1; /* libpng handles the interlace */
-#  endif /* R/W INTERLACING */
-   unsigned int pass           :3; /* current (interlace) pass (0 - 6) */
-
-   /* The next two fields are just used by the IDAT process functions to store
+   /* The next field is just used by the read IDAT process functions to store
     * the state of IDAT processing; they should not be altered or used by other
     * functions.
     */
    unsigned int row_state      :2; /* state of row parsing (internal) */
+#endif /* READ */
+
+#if defined (PNG_READ_INTERLACING_SUPPORTED) ||\
+    defined (PNG_WRITE_INTERLACING_SUPPORTED)
+   unsigned int do_interlace   :1; /* libpng handles the interlace */
+#  endif /* R/W INTERLACING */
+
+   unsigned int pass           :3; /* current (interlace) pass (0 - 6) */
 
    /* The following fields are set by png_row_init to the pixel depths of the
     * pixels at various states.  If transforms are not supported they will
@@ -735,6 +739,28 @@ struct png_struct_def
                                   * received; set by the zstream using code for
                                   * its own purposes. [progressive read] */
 #  endif /* PROGRESSIVE_READ */
+#  ifdef PNG_BENIGN_ERRORS_SUPPORTED
+      unsigned int benign_error_action :2;
+      unsigned int app_warning_action  :2;
+      unsigned int app_error_action    :2;
+#  ifdef PNG_READ_SUPPORTED
+      unsigned int IDAT_error_action   :2;
+#  endif /* READ */
+#  endif /* BENIGN_ERRORS */
+#  ifdef PNG_READ_SUPPORTED
+      /* CRC checking actions, one for critical chunks, one for ancillary
+       * chunks.
+       */
+      unsigned int critical_crc  :2;
+      unsigned int ancillary_crc :2;
+      unsigned int current_crc   :2; /* Cache of one or other of the above */
+#  endif
+#  ifdef PNG_SET_OPTION_SUPPORTED
+#  ifdef PNG_READ_SUPPORTED
+         unsigned int maximum_inflate_window  :1U;
+#  endif /* READ */
+         unsigned int skip_sRGB_profile_check :1U;
+#  endif /* SET_OPTION */
 
    /* MNG SUPPORT */
 #ifdef PNG_MNG_FEATURES_SUPPORTED

pngtest.c

@@ -1,7 +1,7 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.5.25 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.26 [(PENDING RELEASE)]
  * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -130,13 +130,13 @@ static char tIME_string[PNG_tIME_STRING_LENGTH] = "tIME chunk is not present";
 static int
 tIME_to_str(png_structp png_ptr, png_charp ts, png_const_timep t)
 {
-    png_const_charp str = png_convert_to_rfc1123(png_ptr, t);
+   png_const_charp str = png_convert_to_rfc1123(png_ptr, t);
 
-    if (str == NULL)
-        return 0;
+   if (str == NULL)
+       return 0;
 
-    strcpy(ts, str);
-    return 1;
+   strcpy(ts, str);
+   return 1;
 }
 #endif /* older libpng */
 #endif
@@ -240,95 +240,95 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
     *  png_byte pixel_depth   bits per pixel (depth*channels)
     */
 
-    /* Counts the number of zero samples (or zero pixels if color_type is 3 */
+   /* Counts the number of zero samples (or zero pixels if color_type is 3 */
 
-    if (row_info->color_type == 0 || row_info->color_type == 3)
-    {
-       int pos = 0;
-       png_uint_32 n, nstop;
+   if (row_info->color_type == 0 || row_info->color_type == 3)
+   {
+      int pos = 0;
+      png_uint_32 n, nstop;
 
-       for (n = 0, nstop=row_info->width; n<nstop; n++)
-       {
-          if (row_info->bit_depth == 1)
-          {
-             if (((*dp << pos++ ) & 0x80) == 0)
-                zero_samples++;
+      for (n = 0, nstop=row_info->width; n<nstop; n++)
+      {
+         if (row_info->bit_depth == 1)
+         {
+            if (((*dp << pos++ ) & 0x80) == 0)
+               zero_samples++;
 
-             if (pos == 8)
-             {
-                pos = 0;
-                dp++;
-             }
-          }
+            if (pos == 8)
+            {
+               pos = 0;
+               dp++;
+            }
+         }
 
-          if (row_info->bit_depth == 2)
-          {
-             if (((*dp << (pos+=2)) & 0xc0) == 0)
-                zero_samples++;
+         if (row_info->bit_depth == 2)
+         {
+            if (((*dp << (pos+=2)) & 0xc0) == 0)
+               zero_samples++;
 
-             if (pos == 8)
-             {
-                pos = 0;
-                dp++;
-             }
-          }
+            if (pos == 8)
+            {
+               pos = 0;
+               dp++;
+            }
+         }
 
-          if (row_info->bit_depth == 4)
-          {
-             if (((*dp << (pos+=4)) & 0xf0) == 0)
-                zero_samples++;
+         if (row_info->bit_depth == 4)
+         {
+            if (((*dp << (pos+=4)) & 0xf0) == 0)
+               zero_samples++;
 
-             if (pos == 8)
-             {
-                pos = 0;
-                dp++;
-             }
-          }
+            if (pos == 8)
+            {
+               pos = 0;
+               dp++;
+            }
+         }
 
-          if (row_info->bit_depth == 8)
-             if (*dp++ == 0)
-                zero_samples++;
+         if (row_info->bit_depth == 8)
+            if (*dp++ == 0)
+               zero_samples++;
 
-          if (row_info->bit_depth == 16)
-          {
-             if ((*dp | *(dp+1)) == 0)
-                zero_samples++;
-             dp+=2;
-          }
-       }
-    }
-    else /* Other color types */
-    {
-       png_uint_32 n, nstop;
-       int channel;
-       int color_channels = row_info->channels;
-       if (row_info->color_type > 3)
-          color_channels--;
+         if (row_info->bit_depth == 16)
+         {
+            if ((*dp | *(dp+1)) == 0)
+               zero_samples++;
+            dp+=2;
+         }
+      }
+   }
+   else /* Other color types */
+   {
+      png_uint_32 n, nstop;
+      int channel;
+      int color_channels = row_info->channels;
+      if (row_info->color_type > 3)
+         color_channels--;
 
-       for (n = 0, nstop=row_info->width; n<nstop; n++)
-       {
-          for (channel = 0; channel < color_channels; channel++)
-          {
-             if (row_info->bit_depth == 8)
-                if (*dp++ == 0)
-                   zero_samples++;
+      for (n = 0, nstop=row_info->width; n<nstop; n++)
+      {
+         for (channel = 0; channel < color_channels; channel++)
+         {
+            if (row_info->bit_depth == 8)
+               if (*dp++ == 0)
+                  zero_samples++;
 
-             if (row_info->bit_depth == 16)
-             {
-                if ((*dp | *(dp+1)) == 0)
-                   zero_samples++;
+            if (row_info->bit_depth == 16)
+            {
+               if ((*dp | *(dp+1)) == 0)
+                  zero_samples++;
 
-                dp+=2;
-             }
-          }
-          if (row_info->color_type > 3)
-          {
-             dp++;
-             if (row_info->bit_depth == 16)
-                dp++;
-          }
-       }
-    }
+               dp+=2;
+            }
+         }
+         if (row_info->color_type > 3)
+         {
+            dp++;
+            if (row_info->bit_depth == 16)
+               dp++;
+         }
+      }
+   }
 }
 #endif /* WRITE_USER_TRANSFORM */
 
@@ -345,10 +345,10 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
 #ifdef PNG_IO_STATE_SUPPORTED
 void
 pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
-   png_uint_32 io_op);
+    png_uint_32 io_op);
 void
 pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
-   png_uint_32 io_op)
+    png_uint_32 io_op)
 {
    png_uint_32 io_state = png_get_io_state(png_ptr);
    int err = 0;
@@ -532,7 +532,7 @@ PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size)
       memory_infop pinfo;
       png_set_mem_fn(png_ptr, NULL, NULL, NULL);
       pinfo = (memory_infop)png_malloc(png_ptr,
-         (sizeof *pinfo));
+          (sizeof *pinfo));
       pinfo->size = size;
       current_allocation += size;
       total_allocation += size;
@@ -562,7 +562,7 @@ PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size)
 
       if (verbose != 0)
          printf("png_malloc %lu bytes at %p\n", (unsigned long)size,
-            pinfo->pointer);
+             pinfo->pointer);
 
       return (png_voidp)(pinfo->pointer);
    }
@@ -769,9 +769,9 @@ write_vpAg_chunk(png_structp write_ptr)
 
    if (verbose != 0)
       fprintf(STDERR, " vpAg = %lu x %lu, units = %d\n",
-        (unsigned long)user_chunk_data.vpAg_width,
-        (unsigned long)user_chunk_data.vpAg_height,
-        user_chunk_data.vpAg_units);
+          (unsigned long)user_chunk_data.vpAg_width,
+          (unsigned long)user_chunk_data.vpAg_height,
+          user_chunk_data.vpAg_units);
 
    png_save_uint_32(vpag_chunk_data, user_chunk_data.vpAg_width);
    png_save_uint_32(vpag_chunk_data + 4, user_chunk_data.vpAg_height);
@@ -812,7 +812,7 @@ write_chunks(png_structp write_ptr, int location)
 #ifdef PNG_TEXT_SUPPORTED
 static void
 pngtest_check_text_support(png_structp png_ptr, png_textp text_ptr,
-   int num_text)
+    int num_text)
 {
    while (num_text > 0)
    {
@@ -894,26 +894,26 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    pngtest_debug("Allocating read and write structures");
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
    read_ptr =
-      png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL,
-      NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+       png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+       NULL, NULL, NULL, png_debug_malloc, png_debug_free);
 #else
    read_ptr =
-      png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+       png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
    png_set_error_fn(read_ptr, &error_parameters, pngtest_error,
-      pngtest_warning);
+       pngtest_warning);
 
 #ifdef PNG_WRITE_SUPPORTED
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
    write_ptr =
-      png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL,
-      NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+       png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+       NULL, NULL, NULL, png_debug_malloc, png_debug_free);
 #else
    write_ptr =
-      png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+       png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
    png_set_error_fn(write_ptr, &error_parameters, pngtest_error,
-      pngtest_warning);
+       pngtest_warning);
 #endif
    pngtest_debug("Allocating read_info, write_info and end_info structures");
    read_info_ptr = png_create_info_struct(read_ptr);
@@ -926,7 +926,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
    init_callback_info(read_info_ptr);
    png_set_read_user_chunk_fn(read_ptr, &user_chunk_data,
-     read_user_chunk_callback);
+       read_user_chunk_callback);
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
@@ -964,15 +964,16 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #endif
 #endif
 
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
    if (strict != 0)
    {
       /* Treat png_benign_error() as errors on read */
       png_set_benign_errors(read_ptr, 0);
 
-#ifdef PNG_WRITE_SUPPORTED
+# ifdef PNG_WRITE_SUPPORTED
       /* Treat them as errors on write */
       png_set_benign_errors(write_ptr, 0);
-#endif
+# endif
 
       /* if strict is not set, then app warnings and errors are treated as
        * warnings in release builds, but not in unstable builds; this can be
@@ -985,10 +986,15 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       /* Allow application (pngtest) errors and warnings to pass */
       png_set_benign_errors(read_ptr, 1);
 
-#ifdef PNG_WRITE_SUPPORTED
+      /* Turn off CRC and ADLER32 checking while reading */
+      png_set_crc_action(read_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
+
+# ifdef PNG_WRITE_SUPPORTED
       png_set_benign_errors(write_ptr, 1);
-#endif
+# endif
+
    }
+#endif /* BENIGN_ERRORS */
 
    pngtest_debug("Initializing input and output streams");
 #ifdef PNG_STDIO_SUPPORTED
@@ -1001,9 +1007,9 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #  ifdef PNG_WRITE_SUPPORTED
    png_set_write_fn(write_ptr, (png_voidp)fpout,  pngtest_write_data,
 #    ifdef PNG_WRITE_FLUSH_SUPPORTED
-      pngtest_flush);
+       pngtest_flush);
 #    else
-      NULL);
+       NULL);
 #    endif
 #  endif
 #endif
@@ -1043,11 +1049,11 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
     */
 #ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
    png_set_keep_unknown_chunks(read_ptr, PNG_HANDLE_CHUNK_ALWAYS,
-      NULL, 0);
+       NULL, 0);
 #endif
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
    png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_ALWAYS,
-      NULL, 0);
+       NULL, 0);
 #endif
 #endif
 
@@ -1071,7 +1077,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
           &color_type, &interlace_type, &compression_type, &filter_type) != 0)
       {
          png_set_IHDR(write_ptr, write_info_ptr, width, height, bit_depth,
-            color_type, interlace_type, compression_type, filter_type);
+             color_type, interlace_type, compression_type, filter_type);
          /* num_passes may not be available below if interlace support is not
           * provided by libpng for both read and write.
           */
@@ -1098,13 +1104,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_cHRM_SUPPORTED
    {
       png_fixed_point white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
-         blue_y;
+          blue_y;
 
       if (png_get_cHRM_fixed(read_ptr, read_info_ptr, &white_x, &white_y,
-         &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
+          &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
       {
          png_set_cHRM_fixed(write_ptr, write_info_ptr, white_x, white_y, red_x,
-            red_y, green_x, green_y, blue_x, blue_y);
+             red_y, green_x, green_y, blue_x, blue_y);
       }
    }
 #endif
@@ -1121,13 +1127,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_cHRM_SUPPORTED
    {
       double white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
-         blue_y;
+          blue_y;
 
       if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x,
-         &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
+          &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
       {
          png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x,
-            red_y, green_x, green_y, blue_x, blue_y);
+             red_y, green_x, green_y, blue_x, blue_y);
       }
    }
 #endif
@@ -1149,10 +1155,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       int compression_type;
 
       if (png_get_iCCP(read_ptr, read_info_ptr, &name, &compression_type,
-                      &profile, &proflen) != 0)
+          &profile, &proflen) != 0)
       {
          png_set_iCCP(write_ptr, write_info_ptr, name, compression_type,
-                      profile, proflen);
+             profile, proflen);
       }
    }
 #endif
@@ -1209,10 +1215,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       int type, nparams;
 
       if (png_get_pCAL(read_ptr, read_info_ptr, &purpose, &X0, &X1, &type,
-         &nparams, &units, &params) != 0)
+          &nparams, &units, &params) != 0)
       {
          png_set_pCAL(write_ptr, write_info_ptr, purpose, X0, X1, type,
-            nparams, units, params);
+             nparams, units, params);
       }
    }
 #endif
@@ -1242,7 +1248,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       double scal_width, scal_height;
 
       if (png_get_sCAL(read_ptr, read_info_ptr, &unit, &scal_width,
-         &scal_height) != 0)
+          &scal_height) != 0)
       {
          png_set_sCAL(write_ptr, write_info_ptr, unit, scal_width, scal_height);
       }
@@ -1254,7 +1260,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       png_charp scal_width, scal_height;
 
       if (png_get_sCAL_s(read_ptr, read_info_ptr, &unit, &scal_width,
-          &scal_height) != 0)
+           &scal_height) != 0)
       {
          png_set_sCAL_s(write_ptr, write_info_ptr, unit, scal_width,
              scal_height);
@@ -1295,7 +1301,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
             for (i=0; i<num_text; i++)
             {
                printf("   Text compression[%d]=%d\n",
-                     i, text_ptr[i].compression);
+                   i, text_ptr[i].compression);
             }
          }
 
@@ -1332,7 +1338,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       png_color_16p trans_color;
 
       if (png_get_tRNS(read_ptr, read_info_ptr, &trans_alpha, &num_trans,
-         &trans_color) != 0)
+          &trans_color) != 0)
       {
          int sample_max = (1 << bit_depth);
          /* libpng doesn't reject a tRNS chunk with out-of-range samples */
@@ -1351,12 +1357,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       png_unknown_chunkp unknowns;
       int num_unknowns = png_get_unknown_chunks(read_ptr, read_info_ptr,
-         &unknowns);
+          &unknowns);
 
       if (num_unknowns != 0)
       {
          png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns,
-           num_unknowns);
+             num_unknowns);
 #if PNG_LIBPNG_VER < 10600
          /* Copy the locations from the read_info_ptr.  The automatically
           * generated locations in write_end_info_ptr are wrong prior to 1.6.0
@@ -1366,7 +1372,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
             int i;
             for (i = 0; i < num_unknowns; i++)
               png_set_unknown_chunk_location(write_ptr, write_info_ptr, i,
-                unknowns[i].location);
+                  unknowns[i].location);
          }
 #endif
       }
@@ -1386,12 +1392,17 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_write_info(write_ptr, write_info_ptr);
 
    write_chunks(write_ptr, before_IDAT); /* after PLTE */
+
+#ifdef PNG_COMPRESSION_COMPAT
+   /* Test the 'compatibility' setting here, if it is available. */
+   png_set_compression(write_ptr, PNG_COMPRESSION_COMPAT);
+#endif
 #endif
 
 #ifdef SINGLE_ROWBUF_ALLOC
    pngtest_debug("Allocating row buffer...");
    row_buf = (png_bytep)png_malloc(read_ptr,
-      png_get_rowbytes(read_ptr, read_info_ptr));
+       png_get_rowbytes(read_ptr, read_info_ptr));
 
    pngtest_debug1("\t0x%08lx", (unsigned long)row_buf);
 #endif /* SINGLE_ROWBUF_ALLOC */
@@ -1405,10 +1416,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
     */
    if (png_set_interlace_handling(read_ptr) != num_passes)
       png_error(write_ptr,
-            "png_set_interlace_handling(read): wrong pass count ");
+          "png_set_interlace_handling(read): wrong pass count ");
    if (png_set_interlace_handling(write_ptr) != num_passes)
       png_error(write_ptr,
-            "png_set_interlace_handling(write): wrong pass count ");
+          "png_set_interlace_handling(write): wrong pass count ");
 #else /* png_set_interlace_handling not called on either read or write */
 #  define calc_pass_height
 #endif /* not using libpng interlace handling */
@@ -1445,10 +1456,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          pngtest_debug2("Allocating row buffer (pass %d, y = %u)...", pass, y);
 
          row_buf = (png_bytep)png_malloc(read_ptr,
-            png_get_rowbytes(read_ptr, read_info_ptr));
+             png_get_rowbytes(read_ptr, read_info_ptr));
 
          pngtest_debug2("\t0x%08lx (%lu bytes)", (unsigned long)row_buf,
-            (unsigned long)png_get_rowbytes(read_ptr, read_info_ptr));
+             (unsigned long)png_get_rowbytes(read_ptr, read_info_ptr));
 
 #endif /* !SINGLE_ROWBUF_ALLOC */
          png_read_rows(read_ptr, (png_bytepp)&row_buf, NULL, 1);
@@ -1506,7 +1517,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
             for (i=0; i<num_text; i++)
             {
                printf("   Text compression[%d]=%d\n",
-                     i, text_ptr[i].compression);
+                   i, text_ptr[i].compression);
             }
          }
 
@@ -1540,12 +1551,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       png_unknown_chunkp unknowns;
       int num_unknowns = png_get_unknown_chunks(read_ptr, end_info_ptr,
-         &unknowns);
+          &unknowns);
 
       if (num_unknowns != 0)
       {
          png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns,
-           num_unknowns);
+             num_unknowns);
 #if PNG_LIBPNG_VER < 10600
          /* Copy the locations from the read_info_ptr.  The automatically
           * generated locations in write_end_info_ptr are wrong prior to 1.6.0
@@ -1555,7 +1566,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
             int i;
             for (i = 0; i < num_unknowns; i++)
               png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i,
-                unknowns[i].location);
+                  unknowns[i].location);
          }
 #endif
       }
@@ -1589,7 +1600,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       iwidth = png_get_image_width(write_ptr, write_info_ptr);
       iheight = png_get_image_height(write_ptr, write_info_ptr);
       fprintf(STDERR, "\n Image width = %lu, height = %lu\n",
-         (unsigned long)iwidth, (unsigned long)iheight);
+          (unsigned long)iwidth, (unsigned long)iheight);
    }
 #endif
 
@@ -1622,7 +1633,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
        * above, but this is safe.
        */
       fprintf(STDERR, "\n  %s: %d libpng errors found (%d warnings)",
-         inname, error_count, warning_count);
+          inname, error_count, warning_count);
 
       if (strict != 0)
          return (1);
@@ -1633,14 +1644,14 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       else if (unsupported_chunks > 0)
       {
          fprintf(STDERR, "\n  %s: unsupported chunks (%d)%s",
-            inname, unsupported_chunks, strict ? ": IGNORED --strict!" : "");
+             inname, unsupported_chunks, strict ? ": IGNORED --strict!" : "");
       }
 #  endif
 
    else if (warning_count > 0)
    {
       fprintf(STDERR, "\n  %s: %d libpng warnings found",
-         inname, warning_count);
+          inname, warning_count);
 
       if (strict != 0)
          return (1);
@@ -1676,18 +1687,19 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          if (num_in != num_out)
          {
             fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
-                    inname, outname);
+                inname, outname);
 
             if (wrote_question == 0 && unsupported_chunks == 0)
             {
                fprintf(STDERR,
-         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
-                 inname, PNG_ZBUF_SIZE);
+                   "   Was %s written with the same maximum IDAT"
+                   " chunk size (%d bytes),",
+                   inname, PNG_ZBUF_SIZE);
                fprintf(STDERR,
-                 "\n   filtering heuristic (libpng default), compression");
+                   "\n   filtering heuristic (libpng default), compression");
                fprintf(STDERR,
-                 " level (zlib default),\n   and zlib version (%s)?\n\n",
-                 ZLIB_VERSION);
+                   " level (zlib default),\n   and zlib version (%s)?\n\n",
+                   ZLIB_VERSION);
                wrote_question = 1;
             }
 
@@ -1707,17 +1719,18 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          if (memcmp(inbuf, outbuf, num_in))
          {
             fprintf(STDERR, "\nFiles %s and %s are different\n", inname,
-               outname);
+                outname);
 
             if (wrote_question == 0 && unsupported_chunks == 0)
             {
                fprintf(STDERR,
-         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+                   "   Was %s written with the same maximum"
+                   " IDAT chunk size (%d bytes),",
                     inname, PNG_ZBUF_SIZE);
                fprintf(STDERR,
-                 "\n   filtering heuristic (libpng default), compression");
+                   "\n   filtering heuristic (libpng default), compression");
                fprintf(STDERR,
-                 " level (zlib default),\n   and zlib version (%s)?\n\n",
+                   " level (zlib default),\n   and zlib version (%s)?\n\n",
                  ZLIB_VERSION);
                wrote_question = 1;
             }
@@ -1768,12 +1781,12 @@ main(int argc, char *argv[])
    fprintf(STDERR, "%s", png_get_copyright(NULL));
    /* Show the version of libpng used in building the library */
    fprintf(STDERR, " library (%lu):%s",
-      (unsigned long)png_access_version_number(),
-      png_get_header_version(NULL));
+       (unsigned long)png_access_version_number(),
+       png_get_header_version(NULL));
 
    /* Show the version of libpng used in building the application */
    fprintf(STDERR, " pngtest (%lu):%s", (unsigned long)PNG_LIBPNG_VER,
-      PNG_HEADER_VERSION_STRING);
+       PNG_HEADER_VERSION_STRING);
 
    /* Do some consistency checking on the memory allocation settings, I'm
     * not sure this matters, but it is nice to know, the first of these
@@ -1791,7 +1804,7 @@ main(int argc, char *argv[])
    if (strcmp(png_libpng_ver, PNG_LIBPNG_VER_STRING))
    {
       fprintf(STDERR,
-         "Warning: versions are different between png.h and png.c\n");
+          "Warning: versions are different between png.h and png.c\n");
       fprintf(STDERR, "  png.h version: %s\n", PNG_LIBPNG_VER_STRING);
       fprintf(STDERR, "  png.c version: %s\n\n", png_libpng_ver);
       ++ierror;
@@ -1846,19 +1859,19 @@ main(int argc, char *argv[])
    }
 
    if (multiple == 0 && argc == 3 + verbose)
-     outname = argv[2 + verbose];
+      outname = argv[2 + verbose];
 
    if ((multiple == 0 && argc > 3 + verbose) ||
        (multiple != 0 && argc < 2))
    {
-     fprintf(STDERR,
-       "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n",
-        argv[0], argv[0]);
-     fprintf(STDERR,
-       "  reads/writes one PNG file (without -m) or multiple files (-m)\n");
-     fprintf(STDERR,
-       "  with -m %s is used as a temporary file\n", outname);
-     exit(1);
+      fprintf(STDERR,
+          "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n",
+          argv[0], argv[0]);
+      fprintf(STDERR,
+          "  reads/writes one PNG file (without -m) or multiple files (-m)\n");
+      fprintf(STDERR,
+          "  with -m %s is used as a temporary file\n", outname);
+      exit(1);
    }
 
    if (multiple != 0)
@@ -1879,7 +1892,7 @@ main(int argc, char *argv[])
          {
 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
             fprintf(STDERR, "\n PASS (%lu zero samples)\n",
-               (unsigned long)zero_samples);
+                (unsigned long)zero_samples);
 #else
             fprintf(STDERR, " PASS\n");
 #endif
@@ -1899,20 +1912,20 @@ main(int argc, char *argv[])
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
          if (allocation_now != current_allocation)
             fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
-               current_allocation - allocation_now);
+                current_allocation - allocation_now);
 
          if (current_allocation != 0)
          {
             memory_infop pinfo = pinformation;
 
             fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
-               current_allocation);
+                current_allocation);
 
             while (pinfo != NULL)
             {
                fprintf(STDERR, " %lu bytes at %p\n",
-                 (unsigned long)pinfo->size,
-                 pinfo->pointer);
+                   (unsigned long)pinfo->size,
+                   pinfo->pointer);
                pinfo = pinfo->next;
             }
          }
@@ -1920,13 +1933,13 @@ main(int argc, char *argv[])
       }
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
          fprintf(STDERR, " Current memory allocation: %10d bytes\n",
-            current_allocation);
+             current_allocation);
          fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
-            maximum_allocation);
+             maximum_allocation);
          fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
-            total_allocation);
+             total_allocation);
          fprintf(STDERR, "     Number of allocations: %10d\n",
-            num_allocations);
+             num_allocations);
 #endif
    }
 
@@ -1961,7 +1974,7 @@ main(int argc, char *argv[])
             {
 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
                 fprintf(STDERR, "\n PASS (%lu zero samples)\n",
-                   (unsigned long)zero_samples);
+                    (unsigned long)zero_samples);
 #else
                 fprintf(STDERR, " PASS\n");
 #endif
@@ -1988,19 +2001,19 @@ main(int argc, char *argv[])
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
          if (allocation_now != current_allocation)
              fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
-               current_allocation - allocation_now);
+                 current_allocation - allocation_now);
 
          if (current_allocation != 0)
          {
              memory_infop pinfo = pinformation;
 
              fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
-                current_allocation);
+                 current_allocation);
 
              while (pinfo != NULL)
              {
                 fprintf(STDERR, " %lu bytes at %p\n",
-                   (unsigned long)pinfo->size, pinfo->pointer);
+                    (unsigned long)pinfo->size, pinfo->pointer);
                 pinfo = pinfo->next;
              }
           }
@@ -2008,13 +2021,13 @@ main(int argc, char *argv[])
        }
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
        fprintf(STDERR, " Current memory allocation: %10d bytes\n",
-          current_allocation);
+           current_allocation);
        fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
-          maximum_allocation);
+           maximum_allocation);
        fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
-          total_allocation);
+           total_allocation);
        fprintf(STDERR, "     Number of allocations: %10d\n",
-            num_allocations);
+           num_allocations);
 #endif
    }
 
@@ -2023,13 +2036,13 @@ main(int argc, char *argv[])
    t_misc += (t_stop - t_start);
    t_start = t_stop;
    fprintf(STDERR, " CPU time used = %.3f seconds",
-      (t_misc+t_decode+t_encode)/(float)CLOCKS_PER_SEC);
+       (t_misc+t_decode+t_encode)/(float)CLOCKS_PER_SEC);
    fprintf(STDERR, " (decoding %.3f,\n",
-      t_decode/(float)CLOCKS_PER_SEC);
+       t_decode/(float)CLOCKS_PER_SEC);
    fprintf(STDERR, "        encoding %.3f ,",
-      t_encode/(float)CLOCKS_PER_SEC);
+       t_encode/(float)CLOCKS_PER_SEC);
    fprintf(STDERR, " other %.3f seconds)\n\n",
-      t_misc/(float)CLOCKS_PER_SEC);
+       t_misc/(float)CLOCKS_PER_SEC);
 #endif
 
    if (ierror == 0)
@@ -2041,19 +2054,19 @@ main(int argc, char *argv[])
    dummy_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
    fprintf(STDERR, " Default limits:\n");
    fprintf(STDERR, "  width_max  = %lu\n",
-      (unsigned long) png_get_user_width_max(dummy_ptr));
+       (unsigned long) png_get_user_width_max(dummy_ptr));
    fprintf(STDERR, "  height_max = %lu\n",
-      (unsigned long) png_get_user_height_max(dummy_ptr));
+       (unsigned long) png_get_user_height_max(dummy_ptr));
    if (png_get_chunk_cache_max(dummy_ptr) == 0)
       fprintf(STDERR, "  cache_max  = unlimited\n");
    else
       fprintf(STDERR, "  cache_max  = %lu\n",
-         (unsigned long) png_get_chunk_cache_max(dummy_ptr));
+          (unsigned long) png_get_chunk_cache_max(dummy_ptr));
    if (png_get_chunk_malloc_max(dummy_ptr) == 0)
       fprintf(STDERR, "  malloc_max = unlimited\n");
    else
       fprintf(STDERR, "  malloc_max = %lu\n",
-         (unsigned long) png_get_chunk_malloc_max(dummy_ptr));
+          (unsigned long) png_get_chunk_malloc_max(dummy_ptr));
    png_destroy_read_struct(&dummy_ptr, NULL, NULL);
 
    return (int)(ierror != 0);
@@ -2063,11 +2076,11 @@ int
 main(void)
 {
    fprintf(STDERR,
-      " test ignored because libpng was not built with read support\n");
+       " test ignored because libpng was not built with read support\n");
    /* And skip this test */
    return PNG_LIBPNG_VER < 10600 ? 0 : 77;
 }
 #endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_7_0beta80 Your_png_h_is_not_version_1_7_0beta80;
+typedef png_libpng_version_1_7_0beta90 Your_png_h_is_not_version_1_7_0beta90;

pngtrans.c

@@ -586,23 +586,39 @@ set_palette_max(png_structrp png_ptr, png_transformp tr, unsigned int max,
 {
    /* One of these must be true: */
 #  ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-      if (max >= tr->args && !png_ptr->palette_index_check_issued)
+      if (max >= (tr->args & 0x1FFU) && !png_ptr->palette_index_check_issued)
       {
-#        ifdef PNG_READ_SUPPORTED
+         /* In 1.7 only issue the error/warning by default; the 'check' API is
+          * used to enable/disable the check.  Assume that if the app enabled it
+          * then the app will be checking the result with get_palette_max in
+          * read.  In write an error results unless the check is disabled.
+          */
+         if (png_ptr->palette_index_check == PNG_PALETTE_CHECK_DEFAULT
 #           ifdef PNG_WRITE_SUPPORTED
-               (png_ptr->read_struct ? png_chunk_benign_error : png_error)
-#           else /* !WRITE */
-               png_chunk_benign_error
-#           endif /* !WRITE */
-#        else /* !READ */
-            png_error
-#        endif /* !READ */
-            (png_ptr, "palette index too large");
+               || (!png_ptr->read_struct &&
+                   png_ptr->palette_index_check != PNG_PALETTE_CHECK_OFF)
+#           endif /* WRITE */
+            )
+         {
+#           ifdef PNG_READ_SUPPORTED
+#              ifdef PNG_WRITE_SUPPORTED
+                  if (png_ptr->read_struct)
+#              endif /* WRITE */
+                  png_chunk_benign_error(png_ptr, "palette index too large");
+#              ifdef PNG_WRITE_SUPPORTED
+                  else
+#              endif
+#           endif /* READ */
+#           ifdef PNG_WRITE_SUPPORTED
+               png_error(png_ptr, "palette index too large");
+#           endif /* WRITE */
+         }
+
          png_ptr->palette_index_check_issued = 1;
       }
-#  endif
+#  endif /* CHECK_FOR_INVALID_INDEX */
 #  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
-      png_ptr->palette_index_max = png_check_bits(png_ptr, max, 9);
+      png_ptr->palette_index_max = png_check_byte(png_ptr, max);
 #  endif
 
    if (max == format_max)
@@ -642,7 +658,8 @@ palette_max_2bpp(png_transformp *tr, png_transform_controlp tc)
 {
    png_const_bytep sp = png_voidcast(png_const_bytep, tc->sp);
    png_uint_32 width = tc->width;
-   unsigned int max = (*tr)->args; /* saved maximum */
+   const png_uint_32 args = (*tr)->args;
+   unsigned int max = args >> 24; /* saved maximum */
 
    while (width > 0)
    {
@@ -699,7 +716,7 @@ palette_max_2bpp(png_transformp *tr, png_transform_controlp tc)
    }
 
    /* End of input, check the next line. */
-   (*tr)->args = max;
+   (*tr)->args = (max << 24) + (args & 0xFFFFFFU);
 }
 
 static void
@@ -707,7 +724,8 @@ palette_max_4bpp(png_transformp *tr, png_transform_controlp tc)
 {
    png_const_bytep sp = png_voidcast(png_const_bytep, tc->sp);
    png_uint_32 width = tc->width;
-   unsigned int max = (*tr)->args; /* saved maximum */
+   const png_uint_32 args = (*tr)->args;
+   unsigned int max = args >> 24; /* saved maximum */
 
    while (width > 0)
    {
@@ -725,12 +743,12 @@ palette_max_4bpp(png_transformp *tr, png_transform_controlp tc)
          max = (input >> 4) & 0xFU;
    }
 
-   if (max > (*tr)->args)
+   if (max > (args >> 24))
    {
       if (set_palette_max(tc->png_ptr, *tr, max, 15U))
          return;
 
-      (*tr)->args = max;
+      (*tr)->args = (max << 24) + (args & 0xFFFFFFU);
    }
 }
 
@@ -739,7 +757,8 @@ palette_max_8bpp(png_transformp *tr, png_transform_controlp tc)
 {
    png_const_bytep sp = png_voidcast(png_const_bytep, tc->sp);
    png_uint_32 width = tc->width;
-   unsigned int max = (*tr)->args; /* saved maximum */
+   const png_uint_32 args = (*tr)->args;
+   unsigned int max = args >> 24; /* saved maximum */
 
    while (width > 0)
    {
@@ -751,12 +770,12 @@ palette_max_8bpp(png_transformp *tr, png_transform_controlp tc)
       --width;
    }
 
-   if (max > (*tr)->args)
+   if (max > (args >> 24))
    {
       if (set_palette_max(tc->png_ptr, *tr, max, 255U))
          return;
 
-      (*tr)->args = max;
+      (*tr)->args = (max << 24) + (args & 0xFFFFFFU);
    }
 }
 
@@ -764,26 +783,27 @@ static void
 palette_max_init(png_transformp *tr, png_transform_controlp tc)
 {
 #  define png_ptr (tc->png_ptr)
-   if ((tc->format & PNG_FORMAT_FLAG_COLORMAP) != 0)
+   affirm((tc->format & PNG_FORMAT_FLAG_COLORMAP) != 0);
+   debug(tc->init);
+
+   if (tc->init == PNG_TC_INIT_FINAL)
    {
-      if (tc->init == PNG_TC_INIT_FINAL)
+      /* Record the palette depth to check here along with the running total
+       * in the top 8 bits (initially 0, which is always valid).
+       */
+      (*tr)->args = png_ptr->num_palette;
+
+      switch (tc->bit_depth)
       {
-         /* Record the palette depth to check here: */
-         (*tr)->args = png_ptr->num_palette;
-
-         switch (tc->bit_depth)
-         {
-            case 1: (*tr)->fn = palette_max_1bpp; break;
-            case 2: (*tr)->fn = palette_max_2bpp; break;
-            case 4: (*tr)->fn = palette_max_4bpp; break;
-            case 8: (*tr)->fn = palette_max_8bpp; break;
-            default:impossible("palette bit depth");
-         }
+         case 1: (*tr)->fn = palette_max_1bpp; break;
+         case 2: (*tr)->fn = palette_max_2bpp; break;
+         case 4: (*tr)->fn = palette_max_4bpp; break;
+         case 8: (*tr)->fn = palette_max_8bpp; break;
+         default:impossible("palette bit depth");
       }
-   }
 
-   else
-      (*tr)->fn = NULL; /* not applicable */
+      png_ptr->palette_index_have_max = 1U;
+   }
 #  undef png_ptr
 }
 #endif /* PALETTE_MAX */
@@ -792,11 +812,7 @@ palette_max_init(png_transformp *tr, png_transform_controlp tc)
 int PNGAPI
 png_get_palette_max(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
-   if (png_ptr != NULL
-#     ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-         && !png_ptr->palette_index_check_disabled
-#     endif
-      )
+   if (png_ptr != NULL && png_ptr->palette_index_have_max)
       return png_ptr->palette_index_max;
 
    /* This indicates to the caller that the information is not available: */
@@ -805,37 +821,6 @@ png_get_palette_max(png_const_structrp png_ptr, png_const_inforp info_ptr)
 }
 #endif /* GET_PALETTE_MAX */
 
-#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-   /* Whether to report invalid palette index; added at libng-1.5.10.
-    * It is possible for an indexed (color-type==3) PNG file to contain
-    * pixels with invalid (out-of-range) indexes if the PLTE chunk has
-    * fewer entries than the image's bit-depth would allow. We recover
-    * from this gracefully by filling any incomplete palette with zeros
-    * (opaque black).  By default, when this occurs libpng will issue
-    * a benign error.  This API can be used to override that behavior.
-    */
-void PNGAPI
-png_set_check_for_invalid_index(png_structrp png_ptr, int enabled)
-{
-   /* This defaults to 0, therefore *on*: */
-   if (png_ptr != NULL)
-   {
-      if (png_ptr->read_struct)
-#        ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
-            png_ptr->palette_index_check_disabled = enabled <= 0;
-#        else /* !READ_CHECK_FOR_INVALID_INDEX */
-            png_app_error(png_ptr, "no read palette check support");
-#        endif /* !READ_CHECK_FOR_INVALID_INDEX */
-      else /* write struct */
-#        ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
-            png_ptr->palette_index_check_disabled = enabled <= 0;
-#        else /* !WRITE_CHECK_FOR_INVALID_INDEX */
-            png_app_error(png_ptr, "no write palette check support");
-#        endif /* !WRITE_CHECK_FOR_INVALID_INDEX */
-   }
-}
-#endif /* CHECK_FOR_INVALID_INDEX */
-
 void /* PRIVATE */
 png_init_row_info(png_structrp png_ptr)
 {
@@ -856,8 +841,11 @@ png_init_row_info(png_structrp png_ptr)
                defined (PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED)
                (png_ptr->read_struct
 #              ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
-                  && !png_ptr->palette_index_check_disabled)
+                  && (png_ptr->palette_index_check == PNG_PALETTE_CHECK_ON ||
+                      (png_ptr->palette_index_check == PNG_PALETTE_CHECK_DEFAULT
+                       && png_ptr->num_palette < (1U << png_ptr->bit_depth)))
 #              endif /* READ_CHECK_FOR_INVALID_INDEX */
+               )
 #           else /* no READ support */
                0
 #           endif /* READ checks */
@@ -866,8 +854,11 @@ png_init_row_info(png_structrp png_ptr)
                defined (PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
                (!png_ptr->read_struct
 #              ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
-                  && !png_ptr->palette_index_check_disabled)
+                  && (png_ptr->palette_index_check == PNG_PALETTE_CHECK_ON ||
+                      (png_ptr->palette_index_check == PNG_PALETTE_CHECK_DEFAULT
+                       && png_ptr->num_palette < (1U << png_ptr->bit_depth)))
 #              endif /* WRITE_CHECK_FOR_INVALID_INDEX */
+               )
 #           else /* no WRITE support */
                0
 #           endif /* WRITE checks */
@@ -2706,7 +2697,7 @@ png_do_invert_all(png_transformp *transform, png_transform_controlp tc)
    while (png_upcast(void*,dp) < dp_end)
       *dp++ = ~*sp++;
 
-   PNG_UNUSED(transform);
+   PNG_UNUSED(transform)
 }
 
 static void
@@ -2757,7 +2748,7 @@ png_do_invert_channel(png_transformp *transform, png_transform_controlp tc)
       }
    }
 
-   PNG_UNUSED(transform);
+   PNG_UNUSED(transform)
 }
 
 static void
@@ -3588,7 +3579,7 @@ png_set_user_transform_info(png_structrp png_ptr, png_voidp ptr, int depth,
             }
             else
                png_app_error(png_ptr,
-                  "cannot change user info after image start");
+                   "cannot change user info after image start");
          }
 #     else /* !READ_USER_TRANSFORM */
          PNG_UNUSED(depth)

pngwio.c

@@ -33,6 +33,11 @@
 void /* PRIVATE */
 png_write_data(png_structrp png_ptr, png_const_voidp data, png_size_t length)
 {
+   /* This was guaranteed by prior versions of libpng, so app callbacks may
+    * assume it even though it isn't documented to be the case.
+    */
+   debug(length > 0U);
+
    /* NOTE: write_data_fn must not change the buffer!
     * This cast is required because of the API; changing the type of the
     * callback would require every app to change the callback and that change
@@ -40,7 +45,7 @@ png_write_data(png_structrp png_ptr, png_const_voidp data, png_size_t length)
     */
    if (png_ptr->rw_data_fn != NULL )
       png_ptr->rw_data_fn(png_ptr,
-         png_constcast(png_bytep,png_voidcast(png_const_bytep,data)), length);
+          png_constcast(png_bytep,png_voidcast(png_const_bytep,data)), length);
 
    else
       png_app_error(png_ptr, "No write function");
@@ -125,7 +130,7 @@ png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
    if (write_data_fn == NULL)
    {
       png_app_error(png_ptr,
-         "API change: png_set_write_fn requires a function");
+          "API change: png_set_write_fn requires a function");
       return;
    }
 

pngwrite.c

@@ -24,7 +24,7 @@
 /* Write out all the unknown chunks for the current given location */
 static void
 write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
-   unsigned int where)
+    unsigned int where)
 {
    if (info_ptr->unknown_chunks_num != 0)
    {
@@ -61,13 +61,7 @@ write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
               (keep == PNG_HANDLE_CHUNK_AS_DEFAULT &&
                png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS)))
 #endif
-         {
-            /* TODO: review, what is wrong with a zero length unknown chunk? */
-            if (up->size == 0)
-               png_warning(png_ptr, "Writing zero-length unknown chunk");
-
             png_write_chunk(png_ptr, up->name, up->data, up->size);
-         }
       }
    }
 }
@@ -175,7 +169,7 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
              png_ptr->mng_features_permitted != 0)
          {
             png_app_error(png_ptr,
-                  "MNG features are not allowed in a PNG datastream");
+                "MNG features are not allowed in a PNG datastream");
             /* Recovery: disable MNG features: */
             png_ptr->mng_features_permitted = 0;
          }
@@ -183,8 +177,8 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
 
       /* Write IHDR information. */
       png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
-         info_ptr->bit_depth, color_type, info_ptr->compression_type,
-         info_ptr->filter_type, info_ptr->interlace_type);
+          info_ptr->bit_depth, color_type, info_ptr->compression_type,
+          info_ptr->filter_type, info_ptr->interlace_type);
 
 #     ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
          /* This are used for checking later on: */
@@ -241,11 +235,11 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
                 */
                if ((info_ptr->valid & PNG_INFO_sRGB) != 0)
                   png_app_warning(png_ptr,
-                     "profile matches sRGB but writing iCCP instead");
+                      "profile matches sRGB but writing iCCP instead");
 #           endif /* WRITE_sRGB */
 
             png_write_iCCP(png_ptr, info_ptr->iccp_name,
-               info_ptr->iccp_profile);
+                info_ptr->iccp_profile);
          }
 #        ifdef PNG_WRITE_sRGB_SUPPORTED
             else /* iCCP not written */
@@ -286,7 +280,7 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
 
    else /* 1.7.0: flag multiple calls; previously ignored */
       png_app_error(png_ptr,
-            "png_write_info_before_PLTE called more than once");
+          "png_write_info_before_PLTE called more than once");
 }
 
 void PNGAPI
@@ -328,15 +322,15 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
       if ((info_ptr->valid & PNG_INFO_tRNS) !=0)
       {
          png_write_tRNS(png_ptr, info_ptr->trans_alpha,
-            &(info_ptr->trans_color), info_ptr->num_trans,
-            PNG_COLOR_TYPE_FROM_FORMAT(info_ptr->format));
+             &(info_ptr->trans_color), info_ptr->num_trans,
+             PNG_COLOR_TYPE_FROM_FORMAT(info_ptr->format));
       }
 #  endif /* WRITE_tRNS */
 
 #  ifdef PNG_WRITE_bKGD_SUPPORTED
       if ((info_ptr->valid & PNG_INFO_bKGD) != 0)
          png_write_bKGD(png_ptr, &(info_ptr->background),
-            PNG_COLOR_TYPE_FROM_FORMAT(info_ptr->format));
+             PNG_COLOR_TYPE_FROM_FORMAT(info_ptr->format));
 #  endif /* WRITE_bKGD */
 
 #  ifdef PNG_WRITE_hIST_SUPPORTED
@@ -360,7 +354,7 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
 #  ifdef PNG_WRITE_sCAL_SUPPORTED
       if ((info_ptr->valid & PNG_INFO_sCAL) != 0)
          png_write_sCAL_s(png_ptr, info_ptr->scal_unit, info_ptr->scal_s_width,
-               info_ptr->scal_s_height);
+             info_ptr->scal_s_height);
 #  endif /* WRITE_sCAL */
 
 #  ifdef PNG_WRITE_pHYs_SUPPORTED
@@ -544,27 +538,28 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 
    if (png_ptr != NULL)
    {
-      /* Set the IDAT size to the default, the app can change it later. */
-      png_ptr->IDAT_size = PNG_ZBUF_SIZE;
-
-      /* This is a highly dubious configuration option; by default it is off,
-       * but it may be appropriate for private builds that are testing
-       * extensions not conformant to the current specification, or of
-       * applications that must not fail to write at all costs!
-       */
-#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
-      /* In stable builds only warn if an application error can be completely
-       * handled.
-       */
-      png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
-#endif
-
-      /* App warnings are warnings in release (or release candidate) builds but
-       * are errors during development.
-       */
-#if PNG_RELEASE_BUILD
-      png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
-#endif
+#     ifdef PNG_BENIGN_ERRORS_SUPPORTED
+#        if !PNG_RELEASE_BUILD
+            /* Always quit on error prior to release */
+            png_ptr->benign_error_action = PNG_ERROR;
+            png_ptr->app_warning_action = PNG_WARN;
+            png_ptr->app_error_action = PNG_ERROR;
+#        else /* RELEASE_BUILD */
+            /* Allow benign errors on write, subject to app control. */
+#           ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
+               png_ptr->benign_error_action = PNG_WARN;
+               png_ptr->app_error_action = PNG_WARN;
+               png_ptr->app_warning_action = PNG_WARN;
+#           else /* !BENIGN_WRITE_ERRORS */
+               /* libpng build without benign error support; the application
+                * author has to be assumed to be correct, so:
+                */
+               png_ptr->benign_error_action = PNG_ERROR;
+               png_ptr->app_warning_action = PNG_WARN;
+               png_ptr->app_error_action = PNG_ERROR;
+#           endif /* !BENIGN_WRITE_ERRORS */
+#        endif /* RELEASE_BUILD */
+#     endif /* BENIGN_ERRORS */
    }
 
    return png_ptr;
@@ -575,10 +570,10 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
     defined(PNG_WRITE_TRANSFORMS_SUPPORTED)
 static void
 write_row_buffered(png_structrp png_ptr,
-   png_const_bytep row, unsigned int row_info_flags,
-   void (*copy_fn)(png_const_structrp png_ptr, png_bytep row_buffer,
-      png_const_bytep row, png_uint_32 x, unsigned int count, unsigned int p),
-   unsigned int copy_parameter)
+    png_const_bytep row, unsigned int row_info_flags,
+    void (*copy_fn)(png_const_structrp png_ptr, png_bytep row_buffer,
+        png_const_bytep row, png_uint_32 x, unsigned int count, unsigned int p),
+    unsigned int copy_parameter)
 {
    unsigned int max_pixels = png_max_pixel_block(png_ptr);
    const unsigned int pass = png_ptr->pass;
@@ -619,7 +614,7 @@ write_row_buffered(png_structrp png_ptr,
          {
             png_transform_control tc;
 
-            /* The initial values are the memory format, this was worked out in
+            /* The initial values are the memory format; this was worked out in
              * png_init_row_info below.
              */
             memset(&tc, 0, sizeof tc);
@@ -653,7 +648,7 @@ write_row_buffered(png_structrp png_ptr,
        * maxpixels says if this is the final block in the row.
        */
       png_write_png_data(png_ptr, prev_pixels, pixel_buffer.buffer, x,
-            max_pixels, row_info_flags);
+          max_pixels, row_info_flags);
    }
 }
 #endif /* WRITE { INTERLACING || TRANSFORMS } */
@@ -661,19 +656,19 @@ write_row_buffered(png_structrp png_ptr,
 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
 static void
 copy_row(png_const_structrp png_ptr, png_bytep row_buffer,
-   png_const_bytep row, png_uint_32 x, unsigned int count,
-   unsigned int pixel_depth)
+    png_const_bytep row, png_uint_32 x, unsigned int count,
+    unsigned int pixel_depth)
 {
    /* Copy row[x..x+count] pixels to row_buffer. */
    png_copy_row(png_ptr, row_buffer, row, x, count, pixel_depth, 1/*clear*/,
-         0/* x_in_dest; row[x]->row_buffer */);
+       0/* x_in_dest; row[x]->row_buffer */);
 }
 #endif /* WRITE_TRANSFORMS */
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
 static void
 interlace_row_lbd(png_const_structrp png_ptr, png_bytep dp, png_const_bytep sp,
-   png_uint_32 x, unsigned int count, const unsigned int B)
+    png_uint_32 x, unsigned int count, const unsigned int B)
 {
    /* Pick out the correct pixels for the interlace pass.  The basic idea here
     * is to go through the row with a source pointer and a destination pointer
@@ -750,7 +745,7 @@ interlace_row_lbd(png_const_structrp png_ptr, png_bytep dp, png_const_bytep sp,
 
 static void
 interlace_row_byte(png_const_structrp png_ptr, png_bytep dp, png_const_bytep sp,
-   png_uint_32 x, unsigned int count, unsigned int cbytes)
+    png_uint_32 x, unsigned int count, unsigned int cbytes)
 {
    const unsigned int pass = png_ptr->pass;
    const unsigned int inc = PNG_PASS_COL_OFFSET(pass);
@@ -769,12 +764,12 @@ interlace_row_byte(png_const_structrp png_ptr, png_bytep dp, png_const_bytep sp,
 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
 static void
 write_row_core(png_structrp png_ptr, png_const_bytep row,
-      unsigned int row_info_flags)
+    unsigned int row_info_flags)
 {
 #  ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
       if (png_ptr->transform_list != NULL)
          write_row_buffered(png_ptr, row, row_info_flags,
-               copy_row, png_ptr->row_input_pixel_depth);
+             copy_row, png_ptr->row_input_pixel_depth);
 
       else
 #  endif /* WRITE_TRANSFORMS */
@@ -864,12 +859,12 @@ interlace_row(png_structrp png_ptr, png_const_bytep row)
                /*FALL THROUGH*/
             case 1U: /* B will be 0 */
                write_row_buffered(png_ptr, row, row_info_flags,
-                     interlace_row_lbd, B);
+                   interlace_row_lbd, B);
                break;
 
             default: /* Parameter is the pixel size in bytes */
                write_row_buffered(png_ptr, row, row_info_flags,
-                     interlace_row_byte, input_depth >> 3);
+                   interlace_row_byte, input_depth >> 3);
                break;
          }
       } /* pass < 6 */
@@ -900,7 +895,7 @@ interlace_row(png_structrp png_ptr, png_const_bytep row)
  */
 static void
 png_write_rows_internal(png_structrp png_ptr, png_const_bytep *rows,
-      png_uint_32 num_rows)
+    png_uint_32 num_rows)
 {
    if (png_ptr != NULL && num_rows > 0U && rows != NULL)
    {
@@ -1016,9 +1011,9 @@ png_write_rows_internal(png_structrp png_ptr, png_const_bytep *rows,
 
          else /* app does interlace */
             affirm(PNG_PASS_IN_IMAGE(png_ptr->width, png_ptr->height,
-                                     png_ptr->pass) &&
-                   png_ptr->row_number <
-                     PNG_PASS_ROWS(png_ptr->height, png_ptr->pass));
+                png_ptr->pass) &&
+                png_ptr->row_number <
+                PNG_PASS_ROWS(png_ptr->height, png_ptr->pass));
       }
    } /* png_ptr, rows, num_rows all valid */
 
@@ -1047,7 +1042,7 @@ png_write_rows(png_structrp png_ptr, png_bytepp rows, png_uint_32 num_rows)
 
    if (png_ptr != NULL)
       png_write_rows_internal(png_ptr, png_constcast(png_const_bytep*,rows),
-            num_rows);
+          num_rows);
 }
 
 /* Write the image.  You only need to call this function once, even
@@ -1207,7 +1202,7 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
       {
          if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
             png_app_error(png_ptr,
-               "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
+                "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
 
          /* Continue if ignored - this is the pre-1.6.10 behavior */
          png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
@@ -1271,7 +1266,7 @@ static int
 png_image_write_init(png_imagep image)
 {
    png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image,
-          png_safe_error, png_safe_warning);
+       png_safe_error, png_safe_warning);
 
    if (png_ptr != NULL)
    {
@@ -1280,7 +1275,7 @@ png_image_write_init(png_imagep image)
       if (info_ptr != NULL)
       {
          png_controlp control = png_voidcast(png_controlp,
-            png_malloc_warn(png_ptr, (sizeof *control)));
+             png_malloc_warn(png_ptr, (sizeof *control)));
 
          if (control != NULL)
          {
@@ -1331,12 +1326,12 @@ static int
 png_write_image_16bit(png_voidp argument)
 {
    png_image_write_control *display = png_voidcast(png_image_write_control*,
-      argument);
+       argument);
    png_imagep image = display->image;
    png_structrp png_ptr = image->opaque->png_ptr;
 
    png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
-      display->first_row);
+       display->first_row);
    png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
    png_uint_16p row_end;
    const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
@@ -1441,7 +1436,7 @@ png_write_image_16bit(png_voidp argument)
 
 static png_byte
 png_unpremultiply(png_const_structrp png_ptr, png_uint_32 component,
-   png_uint_32 alpha, png_uint_32 reciprocal/*from the above macro*/)
+    png_uint_32 alpha, png_uint_32 reciprocal/*from the above macro*/)
 {
    /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0
     * is represented as some other value there is more likely to be a
@@ -1490,12 +1485,12 @@ static int
 png_write_image_8bit(png_voidp argument)
 {
    png_image_write_control *display = png_voidcast(png_image_write_control*,
-      argument);
+       argument);
    png_imagep image = display->image;
    png_structrp png_ptr = image->opaque->png_ptr;
 
    png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
-      display->first_row);
+       display->first_row);
    png_bytep output_row = png_voidcast(png_bytep, display->local_row);
    png_uint_32 y = image->height;
    const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
@@ -1541,7 +1536,7 @@ png_write_image_8bit(png_voidp argument)
             c = channels;
             do /* always at least one channel */
                *out_ptr++ = png_unpremultiply(png_ptr, *in_ptr++, alpha,
-                  reciprocal);
+                   reciprocal);
             while (--c > 0);
 
             /* Skip to next component (skip the intervening alpha channel) */
@@ -1550,7 +1545,7 @@ png_write_image_8bit(png_voidp argument)
          } /* while out_ptr < row_end */
 
          png_write_row(png_ptr, png_voidcast(png_const_bytep,
-            display->local_row));
+             display->local_row));
          input_row += display->row_bytes/(sizeof (png_uint_16));
       } /* while y */
    }
@@ -1642,7 +1637,7 @@ png_image_set_PLTE(png_image_write_control *display)
             else /* Gray */
                palette[i].blue = palette[i].red = palette[i].green =
                   PNG_sRGB_FROM_LINEAR(display->image->opaque->png_ptr,
-                     255 * *entry);
+                      255 * *entry);
          }
 
          else /* alpha */
@@ -1666,20 +1661,20 @@ png_image_set_PLTE(png_image_write_control *display)
             if (channels >= 3) /* RGB */
             {
                palette[i].blue = png_unpremultiply(
-                  display->image->opaque->png_ptr, entry[afirst + (2 ^ bgr)],
-                  alpha, reciprocal);
+                   display->image->opaque->png_ptr, entry[afirst + (2 ^ bgr)],
+                   alpha, reciprocal);
                palette[i].green = png_unpremultiply(
-                  display->image->opaque->png_ptr, entry[afirst + 1], alpha,
-                  reciprocal);
+                   display->image->opaque->png_ptr, entry[afirst + 1], alpha,
+                   reciprocal);
                palette[i].red = png_unpremultiply(
-                  display->image->opaque->png_ptr, entry[afirst + bgr], alpha,
-                  reciprocal);
+                   display->image->opaque->png_ptr, entry[afirst + bgr], alpha,
+                   reciprocal);
             }
 
             else /* gray */
                palette[i].blue = palette[i].red = palette[i].green =
-                  png_unpremultiply(display->image->opaque->png_ptr,
-                     entry[afirst], alpha, reciprocal);
+                   png_unpremultiply(display->image->opaque->png_ptr,
+                       entry[afirst], alpha, reciprocal);
          }
       }
 
@@ -1726,11 +1721,11 @@ png_image_set_PLTE(png_image_write_control *display)
 #  endif
 
    png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette,
-      entries);
+       entries);
 
    if (num_trans > 0)
       png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS,
-         num_trans, NULL);
+          num_trans, NULL);
 
    image->colormap_entries = entries;
 }
@@ -1739,7 +1734,7 @@ static int
 png_image_write_main(png_voidp argument)
 {
    png_image_write_control *display = png_voidcast(png_image_write_control*,
-      argument);
+       argument);
    png_imagep image = display->image;
    png_structrp png_ptr = image->opaque->png_ptr;
    png_inforp info_ptr = image->opaque->info_ptr;
@@ -1807,24 +1802,24 @@ png_image_write_main(png_voidp argument)
          png_uint_32 entries = image->colormap_entries;
 
          png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
-            entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)),
-            PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
-            PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+             entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)),
+             PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
+             PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
          png_image_set_PLTE(display);
       }
 
       else
          png_error(image->opaque->png_ptr,
-            "no color-map for color-mapped image");
+             "no color-map for color-mapped image");
    }
 
    else
       png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
-         write_16bit ? 16 : 8,
-         ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
-         ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
-         PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+          write_16bit ? 16 : 8,
+          ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
+          ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
+          PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
    /* Counter-intuitively the data transformations must be called *after*
     * png_write_info, not before as in the read code, but the 'set' functions
@@ -1839,11 +1834,11 @@ png_image_write_main(png_voidp argument)
 
       if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
          png_set_cHRM_fixed(png_ptr, info_ptr,
-            /* color      x       y */
-            /* white */ 31270, 32900,
-            /* red   */ 64000, 33000,
-            /* green */ 30000, 60000,
-            /* blue  */ 15000,  6000
+             /* color      x       y */
+             /* white */ 31270, 32900,
+             /* red   */ 64000, 33000,
+             /* green */ 30000, 60000,
+             /* blue  */ 15000,  6000
          );
    }
 
@@ -1915,21 +1910,12 @@ png_image_write_main(png_voidp argument)
       display->row_bytes = row_bytes;
    }
 
-   /* Apply 'fast' options if the flag is set. */
-   if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0)
-   {
-#     ifdef PNG_WRITE_FILTER_SUPPORTED
-         png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);
-#     endif /* WRITE_FILTER */
-      /* NOTE: determined by experiment using pngstest, this reflects some
-       * balance between the time to write the image once and the time to read
-       * it about 50 times.  The speed-up in pngstest was about 10-20% of the
-       * total (user) time on a heavily loaded system.
-       */
-#     ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
-         png_set_compression_level(png_ptr, 3);
-#     endif /* WRITE_CUSTOMIZE_COMPRESSION */
-   }
+   /* Select the right compression mode based on the presence or absence of the
+    * 'fast' flag. This will use whatever options are available in the libpng
+    * build.  It is always supported.
+    */
+   png_set_compression(png_ptr, (image->flags & PNG_IMAGE_FLAG_FAST) != 0 ?
+         PNG_COMPRESSION_HIGH_SPEED : PNG_COMPRESSION_HIGH);
 
    /* Check for the cases that currently require a pre-transform on the row
     * before it is written.  This only applies when the input is 16-bit and
@@ -1939,7 +1925,7 @@ png_image_write_main(png_voidp argument)
        (colormap == 0 && display->convert_to_8bit != 0))
    {
       png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
-         png_get_rowbytes(png_ptr, info_ptr)));
+          png_get_rowbytes(png_ptr, info_ptr)));
       int result;
 
       display->local_row = row;
@@ -1979,10 +1965,10 @@ png_image_write_main(png_voidp argument)
 
 static void (PNGCBAPI
 image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data,
-   png_size_t size)
+    png_size_t size)
 {
    png_image_write_control *display = png_voidcast(png_image_write_control*,
-      png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/);
+       png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/);
    const png_alloc_size_t ob = display->output_bytes;
 
    /* Check for overflow; this should never happen: */
@@ -2013,22 +1999,22 @@ static int
 png_image_write_memory(png_voidp argument)
 {
    png_image_write_control *display = png_voidcast(png_image_write_control*,
-      argument);
+          argument);
 
    /* The rest of the memory-specific init and write_main in an error protected
     * environment.  This case needs to use callbacks for the write operations
     * since libpng has no built in support for writing to memory.
     */
    png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/,
-         image_memory_write, image_memory_flush);
+       image_memory_write, image_memory_flush);
 
    return png_image_write_main(display);
 }
 
 int PNGAPI
 png_image_write_to_memory(png_imagep image, void *memory,
-   png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit,
-   const void *buffer, ptrdiff_t row_stride, const void *colormap)
+    png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit,
+    const void *buffer, ptrdiff_t row_stride, const void *colormap)
 {
    /* Write the image to the given buffer, or count the bytes if it is NULL */
    if (image != NULL && image->version == PNG_IMAGE_VERSION)
@@ -2080,12 +2066,12 @@ png_image_write_to_memory(png_imagep image, void *memory,
 
       else
          return png_image_error(image,
-            "png_image_write_to_memory: invalid argument");
+             "png_image_write_to_memory: invalid argument");
    }
 
    else if (image != NULL)
       return png_image_error(image,
-         "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION");
+          "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION");
 
    else
       return 0;
@@ -2094,7 +2080,7 @@ png_image_write_to_memory(png_imagep image, void *memory,
 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
 int PNGAPI
 png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
-   const void *buffer, ptrdiff_t row_stride, const void *colormap)
+    const void *buffer, ptrdiff_t row_stride, const void *colormap)
 {
    /* Write the image to the given (FILE*). */
    if (image != NULL && image->version == PNG_IMAGE_VERSION)
@@ -2125,12 +2111,12 @@ png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
 
       else
          return png_image_error(image,
-            "png_image_write_to_stdio: invalid argument");
+             "png_image_write_to_stdio: invalid argument");
    }
 
    else if (image != NULL)
       return png_image_error(image,
-         "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
+          "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
 
    else
       return 0;
@@ -2138,8 +2124,8 @@ png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
 
 int PNGAPI
 png_image_write_to_file(png_imagep image, const char *file_name,
-   int convert_to_8bit, const void *buffer, ptrdiff_t row_stride,
-   const void *colormap)
+    int convert_to_8bit, const void *buffer, ptrdiff_t row_stride,
+    const void *colormap)
 {
    /* Write the image to the named file. */
    if (image != NULL && image->version == PNG_IMAGE_VERSION)
@@ -2151,7 +2137,7 @@ png_image_write_to_file(png_imagep image, const char *file_name,
          if (fp != NULL)
          {
             if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
-               row_stride, colormap) != 0)
+                row_stride, colormap) != 0)
             {
                int error; /* from fflush/fclose */
 
@@ -2192,12 +2178,12 @@ png_image_write_to_file(png_imagep image, const char *file_name,
 
       else
          return png_image_error(image,
-            "png_image_write_to_file: invalid argument");
+             "png_image_write_to_file: invalid argument");
    }
 
    else if (image != NULL)
       return png_image_error(image,
-         "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
+          "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
 
    else
       return 0;

pngwtran.c

@@ -1,7 +1,7 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * Last changed in libpng 1.6.17 [(PENDING RELEASE)]
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
  * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)

projects/owatcom/pngconfig.mak

@@ -126,7 +126,7 @@ $# to work, download Brian Kernighan's awk (Brian Kernighan is the author of
 $# awk.)  You can find source code and a built executable (called awk95.exe)
 $# here:
 $#
-$#     http://www.cs.princeton.edu/~bwk/btl.mirror/
+$#     https://www.cs.princeton.edu/~bwk/btl.mirror/
 $#
 $# The executable works just fine.
 $#

projects/vstudio/README.txt

@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.7.0beta80 - May 6, 2016
+libpng version 1.7.0beta90 - August 28, 2017
 
 Copyright (c) 2010,2013,2015 Glenn Randers-Pehrson
 

projects/vstudio/zlib.props

@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.7.0beta80 - May 6, 2016
+ * libpng version 1.7.0beta90 - August 28, 2017
  *
  * Copyright (c) 2011,2013,2014 Glenn Randers-Pehrson
  *

scripts/README.txt

@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.7.0beta80 - May 6, 2016
+Makefiles for  libpng version 1.7.0beta90 - August 28, 2017
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng17.so.17.1.7.0beta80)
+                       (gcc, creates libpng17.so.17.1.7.0beta90)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -33,12 +33,12 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
  makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
  makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng17.so.17.1.7.0beta80)
+                       creates libpng17.so.17.1.7.0beta90)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng17.so.17.1.7.0beta80)
+                       creates libpng17.so.17.1.7.0beta90)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng17.so.17.1.7.0beta80)
+                       creates libpng17.so.17.1.7.0beta90)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile

scripts/def.c

@@ -21,7 +21,7 @@ PNG_DFN "OS2 DESCRIPTION "PNG image compression library""
 PNG_DFN "OS2 CODE PRELOAD MOVEABLE DISCARDABLE"
 PNG_DFN ""
 PNG_DFN "EXPORTS"
-PNG_DFN ";Version 1.7.0beta80"
+PNG_DFN ";Version 1.7.0beta90"
 
 #define PNG_EXPORTA(ordinal, type, name, args, attributes)\
         PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"

scripts/libpng-config-head.in

@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.7.0beta80
+version=1.7.0beta90
 prefix=""
 libdir=""
 libs=""

scripts/libpng.pc.in

@@ -5,6 +5,6 @@ includedir=@includedir@/libpng17
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.7.0beta80
+Version: 1.7.0beta90
 Libs: -L${libdir} -lpng17
 Cflags: -I${includedir}

scripts/makefile.linux

@@ -92,7 +92,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
 
 .c.pic.o:
-	$(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -fPIC -o $@ $*.c
 
 all: libpng.a $(LIBSO) pngtest pngtest-static libpng.pc libpng-config
 

scripts/makefile.ne12bsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng17
 
 LIB=	png17
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.7.0beta80
+SHLIB_MINOR=	1.7.0beta90
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c

scripts/makefile.netbsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include
 
 LIB=	png
 SHLIB_MAJOR=	17
-SHLIB_MINOR=	1.7.0beta80
+SHLIB_MINOR=	1.7.0beta90
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c

scripts/makefile.openbsd

@@ -11,7 +11,7 @@ LIBDIR=	${PREFIX}/lib
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	17
-SHLIB_MINOR=	1.7.0beta80
+SHLIB_MINOR=	1.7.0beta90
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \

scripts/makefile.solaris-x86

@@ -83,7 +83,7 @@ OBJSDLL = $(OBJS:.o=.pic.o)
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
 
 .c.pic.o:
-	$(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -fPIC -o $@ $*.c
 
 all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
 

scripts/pnglibconf.dfa

@@ -285,33 +285,16 @@ setting ZLIB_HEADER default <zlib.h>
 # must be made by the user)
 option SET_OPTION disabled
 
-# Run-time setting of parameters, enabled as required below
-option SETTING disabled
-
 # To support hardware specific optimizations libpng can include a hardware
 # specific header at build time, this setting records the included header:
 setting EXTENSION_HEADER
 
-# These settings configure the default compression level (0-9) and 'strategy';
-# strategy is as defined by the implementors of zlib. It describes the input
-# data and modifies the zlib parameters in an attempt to optimize the balance
-# between search and huffman encoding in the zlib algorithms.  The defaults are
-# the zlib.h defaults - the apparently recursive definition does not arise
-# because the name of the setting is prefixed by PNG_
-#
-# The TEXT values are the defaults when writing compressed text (all forms)
+# This setting controls the default zlib compression settings.  See the
+# description of the values in png.h
+setting DEFAULT_COMPRESSION_LEVEL default PNG_COMPRESSION_MEDIUM
 
 # The '@' here means to substitute the value when pnglibconf.h is built
 setting ZLIB_VERNUM default @ZLIB_VERNUM
-setting Z_DEFAULT_COMPRESSION default @Z_DEFAULT_COMPRESSION
-# By experiment even if other strategies are favored over the zlib default it
-# still comes out best for 47% of files tested; more than filtered, the next
-# best, for 38.8% of files tested.
-setting Z_DEFAULT_STRATEGY default @Z_DEFAULT_STRATEGY
-setting Z_DEFAULT_NOFILTER_STRATEGY default @Z_DEFAULT_STRATEGY
-
-setting TEXT_Z_DEFAULT_COMPRESSION default @Z_DEFAULT_COMPRESSION
-setting TEXT_Z_DEFAULT_STRATEGY default @Z_DEFAULT_STRATEGY
 
 # Define this to something that will stop, at least, the current thread; control
 # cannot proceed beyond the PNG_ABORT operation and compilation of pngerror.c is
@@ -343,7 +326,6 @@ option WRITE_INT_FUNCTIONS disabled
 #
 # WARNINGS: normally on, if off no warnings are generated
 # ERROR_TEXT: normally on, if off errors happen but there is no message
-# ERROR_NUMBERS: unimplemented feature, therefore disabled
 # BENIGN_ERRORS: support for just issuing warnings for recoverable errors
 #
 # BENIGN_READ_ERRORS:
@@ -360,7 +342,6 @@ option WRITE_INT_FUNCTIONS disabled
 
 option WARNINGS
 option ERROR_TEXT
-option ERROR_NUMBERS disabled
 
 option BENIGN_ERRORS
 option BENIGN_WRITE_ERRORS requires BENIGN_ERRORS disabled
@@ -515,7 +496,7 @@ option READ_QUANTIZE requires READ_TRANSFORMS enables TRANSFORM_MECH
 # gamma processing; and it is an enormous waste of space.  You just need to
 # remove the use of libpng APIs that depend on it.
 option READ_GAMMA requires READ_TRANSFORMS, READ_gAMA, READ_sRGB,
-   enables TRANSFORM_MECH, READ_SCALE_16_TO_8, READ_EXPAND, SETTING
+   enables TRANSFORM_MECH, READ_SCALE_16_TO_8, READ_EXPAND
 
 option READ_ALPHA_MODE requires READ_TRANSFORMS, READ_GAMMA, READ_BACKGROUND
 option READ_BACKGROUND requires READ_TRANSFORMS, READ_STRIP_ALPHA, READ_GAMMA,
@@ -798,8 +779,12 @@ setting sCAL_PRECISION default 5
 # written IDAT chunks.  It can be any (zlib) uInt value, however this amount of
 # data has to be buffered on write so it is recommended that a smaller size be
 # used unless saving the 12-byte chunk overhead is necessary.
+#
+# If not set libpng uses the DEFAULT_COMPRESSION_LEVEL setting to determine
+# something appropriate.  The value below is only used for 'MEDIUM' compression
+# (which is the default: see below.)
 
-setting ZBUF_SIZE default 4096
+setting ZBUF_SIZE default 8192
 
 # This is the size of the decompression buffer used when counting or checking
 # the decompressed size of an LZ stream from a compressed ancilliary chunk; the
@@ -852,10 +837,8 @@ option WRITE_tEXt enables WRITE_TEXT
 option WRITE_zTXt enables WRITE_TEXT
 option WRITE_iTXt enables WRITE_TEXT
 
-# This only affects support of the optional PLTE chunk in RGB and RGBA
-# images.  Notice that READ_ANCILLARY_CHUNKS therefore disables part
-# of the regular chunk reading too.
-
+# WARNING: unless this option is set PLTE chunks in non-palette images are
+# simply discarded (with checking of the CRC, but nothing else.)
 option READ_OPT_PLTE requires READ_ANCILLARY_CHUNKS
 
 # Unknown chunk handling
@@ -935,31 +918,8 @@ option CONVERT_tIME requires WRITE_ANCILLARY_CHUNKS
 #     the 'first' (lowest numbered) filter will be selected an this typically
 #     works out as PNG_FILTER_VALUE_NONE.
 #
-#  COMPRESSION_BUFFER_MAX
-#     WARNING: take care if you set this.  This is the maximum amount of input
-#     data that the implementation of deflate can consume before it outputs a
-#     Huffman table for that data.  I.e. before it commits to an encoding of the
-#     data it has read.  This is used solely to implement a limit on the amount
-#     of image data buffering that occurs inside libpng before filter selection
-#     is done.  Normally the limit is never reached because of the next setting,
-#     but this is a compile time limit and it is intended to prevent a potential
-#     DNS service as a result of an application setting the libpng equivalent of
-#     volume level 11 (read the wikipedia article on "Up to eleven").
-#
-#     NOTE: the image of a black cat in a coal mine obviously requires this
-#     limit, but some more valid images can get very close; well over 8MByte.
-#
-#  COMPRESSION_BUFFER_LIMIT
-#     This is the (overrideable) default for the amount of memory libpng will
-#     buffer before selecting a filter for a row.  It is limited itself to
-#     COMPRESSION_BUFFER_MAX as values above that level make no change (see the
-#     previous paragraph.)
-#
-#  See png.h for more description of these options.
 option WRITE_FILTER requires WRITE
-option SELECT_FILTER requires WRITE_FILTER disabled
-setting COMPRESSION_BUFFER_MAX default 8453377
-setting COMPRESSION_BUFFER_LIMIT default 8453377
+option SELECT_FILTER requires WRITE_FILTER
 
 # added at libpng-1.5.4
 
@@ -979,8 +939,10 @@ option WRITE_zTXt enables WRITE_COMPRESSED_TEXT
 # leave the row_pointers member out of the info structure.
 
 option INFO_IMAGE disabled
-option READ_PNG requires READ_IMAGE READ_TRANSFORMS enables INFO_IMAGE
-option WRITE_PNG requires WRITE WRITE_TRANSFORMS enables INFO_IMAGE
+option READ_PNG requires READ_IMAGE READ_TRANSFORMS READ_INTERLACING,
+   enables INFO_IMAGE
+option WRITE_PNG requires WRITE WRITE_TRANSFORMS WRITE_INTERLACING,
+   enables INFO_IMAGE
 
 # There are four options here, two each for read and write.  By default they are
 # all switched on.

scripts/pnglibconf.h.prebuilt

@@ -1,8 +1,8 @@
-/* libpng 1.7.0beta80 STANDARD API DEFINITION */
+/* libpng 1.7.0beta90 STANDARD API DEFINITION */
 
 /* pnglibconf.h - library build configuration */
 
-/* libpng version 1.7.0beta80, May 6, 2016 */
+/* libpng version 1.7.0beta90, August 28, 2017 */
 
 /* Copyright (c) 1998-2016 Glenn Randers-Pehrson */
 
@@ -27,7 +27,6 @@
 #define PNG_CONSOLE_IO_SUPPORTED
 #define PNG_CONVERT_tIME_SUPPORTED
 #define PNG_EASY_ACCESS_SUPPORTED
-/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
 #define PNG_ERROR_TEXT_SUPPORTED
 #define PNG_FIXED_POINT_SUPPORTED
 #define PNG_FLOATING_ARITHMETIC_SUPPORTED
@@ -100,10 +99,9 @@
 #define PNG_READ_tRNS_SUPPORTED
 #define PNG_READ_zTXt_SUPPORTED
 #define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
-/*#undef PNG_SELECT_FILTER_SUPPORTED*/
+#define PNG_SELECT_FILTER_SUPPORTED
 #define PNG_SEQUENTIAL_READ_SUPPORTED
 #define PNG_SETJMP_SUPPORTED
-#define PNG_SETTING_SUPPORTED
 #define PNG_SET_OPTION_SUPPORTED
 #define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SET_USER_LIMITS_SUPPORTED
@@ -192,8 +190,7 @@
 /* settings */
 #define PNG_ABORT { (abort()); }
 #define PNG_API_RULE 0
-#define PNG_COMPRESSION_BUFFER_LIMIT 8453377
-#define PNG_COMPRESSION_BUFFER_MAX 8453377
+#define PNG_DEFAULT_COMPRESSION_LEVEL PNG_COMPRESSION_MEDIUM
 #define PNG_DEFAULT_GAMMA_ACCURACY 665
 #define PNG_DEFAULT_READ_MACROS 1
 #define PNG_GAMMA_THRESHOLD_FIXED 153
@@ -203,8 +200,6 @@
 #define PNG_QUANTIZE_BLUE_BITS 5
 #define PNG_QUANTIZE_GREEN_BITS 5
 #define PNG_QUANTIZE_RED_BITS 5
-#define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1)
-#define PNG_TEXT_Z_DEFAULT_STRATEGY 0
 #define PNG_USER_CHUNK_CACHE_MAX 1000
 #define PNG_USER_CHUNK_MALLOC_MAX 8000000
 #define PNG_USER_HEIGHT_MAX 1000000
@@ -212,9 +207,6 @@
 #define PNG_ZBUF_SIZE 4096
 #define PNG_ZLIB_HEADER <zlib.h>
 #define PNG_ZLIB_VERNUM 0
-#define PNG_Z_DEFAULT_COMPRESSION (-1)
-#define PNG_Z_DEFAULT_NOFILTER_STRATEGY 0
-#define PNG_Z_DEFAULT_STRATEGY 0
 #define PNG_sCAL_PRECISION 5
 #define PNG_sRGB_PROFILE_CHECKS 2
 /* end of settings */

scripts/symbols.def

@@ -1,4 +1,4 @@
-;Version 1.7.0beta80
+;Version 1.7.0beta90
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng
@@ -53,7 +53,6 @@ EXPORTS
  png_set_strip_16 @48
  png_set_quantize @49
  png_set_gamma @50
- png_set_flush @51
  png_write_flush @52
  png_start_read_image @53
  png_read_update_info @54
@@ -68,14 +67,6 @@ EXPORTS
  png_destroy_info_struct @63
  png_destroy_read_struct @64
  png_destroy_write_struct @65
- png_set_crc_action @66
- png_set_filter @67
- png_set_filter_heuristics @68
- png_set_compression_level @69
- png_set_compression_mem_level @70
- png_set_compression_strategy @71
- png_set_compression_window_bits @72
- png_set_compression_method @73
  png_init_io @74
  png_set_error_fn @75
  png_get_error_ptr @76
@@ -108,7 +99,6 @@ EXPORTS
  png_chunk_warning @106
  png_benign_error @107
  png_chunk_benign_error @108
- png_set_benign_errors @109
  png_get_valid @110
  png_get_rowbytes @111
  png_get_rows @112
@@ -184,7 +174,6 @@ EXPORTS
  png_get_header_version @182
  png_get_libpng_ver @183
  png_permit_mng_features @184
- png_set_strip_error_numbers @185
  png_set_user_limits @186
  png_get_user_width_max @187
  png_get_user_height_max @188
@@ -206,7 +195,6 @@ EXPORTS
  png_save_uint_32 @205
  png_save_uint_16 @207
  png_set_gamma_fixed @208
- png_set_filter_heuristics_fixed @209
  png_get_pixel_aspect_ratio_fixed @210
  png_get_x_offset_inches_fixed @211
  png_get_y_offset_inches_fixed @212
@@ -219,11 +207,6 @@ EXPORTS
  png_process_data_pause @219
  png_process_data_skip @220
  png_set_expand_16 @221
- png_set_text_compression_level @222
- png_set_text_compression_mem_level @223
- png_set_text_compression_strategy @224
- png_set_text_compression_window_bits @225
- png_set_text_compression_method @226
  png_set_alpha_mode @227
  png_set_alpha_mode_fixed @228
  png_set_scale_16 @229
@@ -239,9 +222,7 @@ EXPORTS
  png_image_write_to_file @239
  png_image_write_to_stdio @240
  png_convert_to_rfc1123_buffer @241
- png_set_check_for_invalid_index @242
  png_get_palette_max @243
- png_set_option @244
  png_image_write_to_memory @245
  png_memory_format @246
  png_memory_channel_depth @247

tests/pngtest

@@ -1,2 +1,7 @@
 #!/bin/sh
+./pngtest --relaxed ${srcdir}/tests/badcrc.png
+./pngtest --relaxed ${srcdir}/tests/badadler.png
+./pngtest --relaxed ${srcdir}/tests/bad_iccp.png
+./pngtest --relaxed ${srcdir}/tests/huge_idat.png
+./pngtest --relaxed ${srcdir}/tests/empty_ancillary_chunks.png
 exec ./pngtest --strict ${srcdir}/pngtest.png