[libpng16] Imported from libpng-1.6.18rc01.tar

[libpng16] Added Mans Rullgard and James Yu to the list of Contributing Authors
[libpng16] Fixed new typo in LICENSE
2025-07-10 18:04:09 +02:00 · 2015-07-09 11:14:03 -05:00 · 2015-07-09 11:11:49 -05:00 · 2015-07-04 20:58:24 -05:00 · 2015-07-04 20:43:09 -05:00 · 2015-07-04 20:42:56 -05:00
227 changed files with 2090 additions and 3004 deletions
--- a/121
+++ b/121
@@ -1,47 +1,110 @@
-Libpng 1.6.20 - December 3, 2015
+Libpng 1.6.18rc01 - July 9, 2015

-This is a public release of libpng, intended for use in production codes.
+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.

 Files available for download:

 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script

-   libpng-1.6.20.tar.xz (LZMA-compressed, recommended)
-   libpng-1.6.20.tar.gz
+   1.6.18rc01.tar.xz (LZMA-compressed, recommended)
+   1.6.18rc01.tar.gz

 Source files with CRLF line endings (for Windows), without the
 "configure" script

-   /scratch/glennrp/Libpng16/lpng1620.7z  (LZMA-compressed, recommended)
-   /scratch/glennrp/Libpng16/lpng1620.zip
+   lp1618r01.7z  (LZMA-compressed, recommended)
+   lp1618r01.zip

 Other information:

-   libpng-1.6.20-README.txt
-   libpng-1.6.20-LICENSE.txt
-   libpng-1.6.20-*.asc (armored detached GPG signatures)
+   1.6.18rc01-README.txt
+   1.6.18rc01-LICENSE.txt
+   libpng-1.6.18rc01-*.asc (armored detached GPG signatures)

-Changes since the last public release (1.6.19):
-  Avoid potential pointer overflow/underflow in png_handle_sPLT() and
-    png_handle_pCAL() (Bug report by John Regehr).
-  Fixed incorrect implementation of png_set_PLTE() that uses png_ptr
-    not info_ptr, that left png_set_PLTE() open to the CVE-2015-8126
-    vulnerability.
-  Backported tests from libpng-1.7.0beta69.
-  Fixed an error in handling of bad zlib CMINFO field in pngfix, found by
-    American Fuzzy Lop, reported by Brian Carpenter.  inflate() doesn't
-    immediately fault a bad CMINFO field; instead a 'too far back' error
-    happens later (at least some times).  pngfix failed to limit CMINFO to
-    the allowed values but then assumed that window_bits was in range,
-    triggering an assert. The bug is mostly harmless; the PNG file cannot
-    be fixed.
-  In libpng 1.6 zlib initialization was changed to use the window size
-    in the zlib stream, not a fixed value. This causes some invalid images,
-    where CINFO is too large, to display 'correctly' if the rest of the
-    data is valid.  This provides a workaround for zlib versions where the
-    error arises (ones that support the API change to use the window size
-    in the stream).
+Changes since the last public release (1.6.17):
+
+Version 1.6.18beta01 [April 1, 2015]
+  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
+    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+    bug report by Andrew Church).
+  Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c.  This
+    fixes some arithmetic errors that caused some tests to fail on
+    some 32-bit platforms (Bug reports by Peter Breitenlohner [i686]
+    and Petr Gajdos [i586]).
+
+Version 1.6.18beta02 [April 26, 2015]
+  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
+    (Bug report by Viktor Szaka'ts).
+
+Version 1.6.18beta03 [May 6, 2015]
+  Replaced "unexpected" with an integer (0xabadca11) in pngset.c
+    where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1.
+  Added contrib/examples/simpleover.c, to demonstrate how to handle
+    alpha compositing of multiple images, using the "simplified API"
+    and an example PNG generation tool, contrib/examples/genpng.c
+    (John Bowler).
+
+Version 1.6.18beta04 [May 20, 2015]
+  PNG_RELEASE_BUILD replaces tests where the code depended on the build base
+    type and can be defined on the command line, allowing testing in beta
+    builds (John Bowler).
+  Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c
+  Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
+    report from Christopher Ferris).
+
+Version 1.6.18beta05 [May 31, 2015]
+  Backport filter selection code from libpng-1.7.0beta51, to combine
+    sub_row, up_row, avg_row, and paeth_row into try_row and tst_row.
+  Changed png_voidcast(), etc., to voidcast(), etc., in contrib/tools/pngfix.c
+    to avoid confusion with the libpng private macros.
+  Fixed old cut&paste bug in the weighted filter selection code in
+    pngwutil.c, introduced in libpng-0.95, March 1997.
+
+Version 1.6.18beta06 [June 1, 2015]
+  Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the
+    compiled library size. It never worked properly and as far as we can
+    tell, no one uses it. The png_set_filter_heuristics() and
+    png_set_filter_heuristics_fixed() APIs are retained but deprecated
+    and do nothing.
+
+Version 1.6.18beta07 [June 6, 2015]
+  Removed non-working progressive reader 'skip' function. This
+    function has apparently never been used. It was implemented
+    to support back-door modification of png_struct in libpng-1.4.x
+    but (because it does nothing and cannot do anything) was apparently
+    never tested (John Bowler).
+  Fixed cexcept.h in which GCC 5 now reports that one of the auto
+    variables in the Try macro needs to be volatile to prevent value
+    being lost over the setjmp (John Bowler).
+  Fixed NO_WRITE_FILTER and -Wconversion build breaks (John Bowler).
+  Fix g++ build breaks (John Bowler).
+  Quieted some Coverity issues in pngfix.c, png-fix-itxt.c, pngvalid.c,
+    pngstest.c, and pngimage.c. Most seem harmless, but png-fix-itxt
+    would only work with iTXt chunks with length 255 or less.
+  Added #ifdef's to contrib/examples programs so people don't try
+    to compile them without the minimum required support enabled
+    (suggested by Flavio Medeiros).
+
+Version 1.6.18beta08 [June 30, 2015]
+  Eliminated the final two Coverity defects (insecure temporary file
+    handling in contrib/libtests/pngstest.c; possible overflow of
+    unsigned char in contrib/tools/png-fix-itxt.c). To use the "secure"
+    file handling, define PNG_USE_MKSTEMP, otherwise "tmpfile()" will
+    be used.
+  Removed some unused WEIGHTED_FILTER macros from png.h and pngstruct.h
+
+Version 1.6.18beta09 [July 5, 2015]
+  Removed some useless typecasts from contrib/tools/png-fix-itxt.c
+  Fixed a new signed-unsigned comparison in pngrtran.c (Max Stepin).
+  Replaced arbitrary use of 'extern' with #define PNG_LINKAGE_*.  To
+    preserve API compatibility, the new defines all default to "extern"
+    (requested by Jan Nijtmans).
+
+Version 1.6.18rc01 [July 9, 2015]
+  Belatedly added Mans Rullgard and James Yu to the list of Contributing
+    Authors.

 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
--- a/181
+++ b/181
@@ -3756,9 +3756,8 @@ Version 1.5.7beta04 [November 17, 2011]

 Version 1.5.7beta05 [November 25, 2011]
  Removed "zTXt" from warning in generic chunk decompression function.
-  Validate time settings passed to png_set_tIME() and png_convert_to_rfc1123()
-    (Frank Busse). Note: This prevented CVE-2015-7981 from affecting
-    libpng-1.5.7 and later.
+  Validate time settings passed to pngset() and png_convert_to_rfc1123()
+    (Frank Busse).
  Added MINGW support to CMakeLists.txt
  Reject invalid compression flag or method when reading the iTXt chunk.
  Backed out 'simplified' API changes. The API seems too complex and there
@@ -3804,13 +3803,12 @@ Version 1.6.0beta01 [December 15, 2011]
    (the other two required headers aren't used).  Non-ANSI systems that don't
    have stddef.h or limits.h will have to provide an appropriate fake
    containing the relevant types and #defines.
-  Dropped support for 16-bit platforms. The use of FAR/far has been eliminated
-    and the definition of png_alloc_size_t is now controlled by a flag so
-    that 'small size_t' systems can select it if necessary.  Libpng 1.6 may
-    not currently work on such systems -- it seems likely that it will
-    ask 'malloc' for more than 65535 bytes with any image that has a
-    sufficiently large row size (rather than simply failing to read such
-    images).
+  The use of FAR/far has been eliminated and the definition of png_alloc_size_t
+    is now controlled by a flag so that 'small size_t' systems can select it
+    if necessary.  Libpng 1.6 may not currently work on such systems -- it
+    seems likely that it will ask 'malloc' for more than 65535 bytes with any
+    image that has a sufficiently large row size (rather than simply failing
+    to read such images).
  New tools directory containing tools used to generate libpng code.
  Fixed race conditions in parallel make builds. With higher degrees of
    parallelism during 'make' the use of the same temporary file names such
@@ -4422,7 +4420,7 @@ Version 1.6.1beta02 [February 19, 2013]

 Version 1.6.1beta03 [February 22, 2013]
  Fixed ALIGNED_MEMORY support.
-  Added a new configure option:
+  Allow run-time ARM NEON checking to be disabled. A new configure option:
    --enable-arm-neon=always will stop the run-time checks. New checks
    within arm/arm_init.c will cause the code not to be compiled unless
    __ARM_NEON__ is set. This should make it fail safe (if someone asks
@@ -4441,10 +4439,10 @@ Version 1.6.1beta05 [March 1, 2013]
 Version 1.6.1beta06 [March 4, 2013]
  Better documentation of unknown handling API interactions.
  Corrected Android builds and corrected libpng.vers with symbol
-    prefixing.  It also makes those tests compile and link on Android.
-  Added an API png_set_option() to set optimization options externally,
+    prefixing. This adds an API to set optimization options externally,
    providing an alternative and general solution for the non-portable
-    run-time tests used by the ARM Neon code, using the PNG_ARM_NEON option.
+    run-time tests used by the ARM Neon code.  It also makes those tests
+    compile and link on Android.
  The order of settings vs options in pnglibconf.h is reversed to allow
    settings to depend on options and options can now set (or override) the
    defaults for settings.
@@ -4542,8 +4540,7 @@ Version 1.6.3beta05 [May 9, 2013]
  Calculate our own zlib windowBits when decoding rather than trusting the
    CMF bytes in the PNG datastream.
  Added an option to force maximum window size for inflating, which was
-    the behavior of libpng15 and earlier, via a new PNG_MAXIMUM_INFLATE_WINDOW
-    option for png_set_options().
+    the behavior of libpng15 and earlier.
  Added png-fix-itxt and png-fix-too-far-back to the built programs and
    removed warnings from the source code and timepng that are revealed as
    a result.
@@ -5146,9 +5143,7 @@ Version 1.6.17beta01 [January 29, 2015]
  Added testing of png_set_packing() to pngvalid.c
  Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
  Implement previously untested cases of libpng transforms in pngvalid.c
-  Fixed byte order in png_do_read_filler() with 16-bit input. Previously
-    the high and low bytes of the filler, from png_set_filler() or from
-    png_set_add_alpha(), were read in the wrong order.
+  Fixed byte order in 2-byte filler, in png_do_read_filler().
  Made the check for out-of-range values in png_set_tRNS() detect
    values that are exactly 2^bit_depth, and work on 16-bit platforms.
  Merged some parts of libpng-1.6.17beta01 and libpng-1.7.0beta47.
@@ -5230,7 +5225,7 @@ Version 1.6.18beta01 [April 1, 2015]

 Version 1.6.18beta02 [April 26, 2015]
  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
-    (Bug report by Viktor Szakats).
+    (Bug report by Viktor Szaka'ts).

 Version 1.6.18beta03 [May 6, 2015]
  Replaced "unexpected" with an integer (0xabadca11) in pngset.c
@@ -5300,152 +5295,6 @@ Version 1.6.18rc01 [July 9, 2015]
  Belatedly added Mans Rullgard and James Yu to the list of Contributing
    Authors.

-Version 1.6.18rc02 [July 12, 2015]
-  Restored unused FILTER_HEURISTIC macros removed at libpng-1.6.18beta08
-    to png.h to avoid compatibility warnings.
-
-Version 1.6.18rc03 [July 15, 2015]
-  Minor changes to the man page
-
-Version 1.6.18 [July 23, 2015]
-  No changes.
-
-Version 1.6.19beta01 [July 30, 2015]
-  Updated obsolete information about the simplified API macros in the
-    manual pages (Bug report by Arc Riley).
-  Avoid potentially dereferencing NULL info_ptr in png_info_init_3().
-  Rearranged png.h to put the major sections in the same order as
-    in libpng17.
-  Eliminated unused PNG_COST_SHIFT, PNG_WEIGHT_SHIFT, PNG_COST_FACTOR, and
-    PNG_WEIGHT_FACTOR macros.
-  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
-    (Bug report by Viktor Szakats).  Several warnings remain and are
-    unavoidable, where we test for overflow.
-  Fixed potential leak of png_pixels in contrib/pngminus/pnm2png.c
-  Fixed uninitialized variable in contrib/gregbook/rpng2-x.c
-
-Version 1.6.19beta02 [August 19, 2015]
-  Moved config.h.in~ from the "libpng_autotools_files" list to the
-    "libpng_autotools_extra" list in autogen.sh because it was causing a
-    false positive for missing files (bug report by Robert C. Seacord).
-  Removed unreachable "break" statements in png.c, pngread.c, and pngrtran.c
-    to suppress clang warnings (Bug report by Viktor Szakats).
-  Fixed some bad links in the man page.
-  Changed "n bit" to "n-bit" in comments.
-  Added signed/unsigned 16-bit safety net. This removes the dubious
-    0x8000 flag definitions on 16-bit systems. They aren't supported
-    yet the defs *probably* work, however it seems much safer to do this
-    and be advised if anyone, contrary to advice, is building libpng 1.6
-    on a 16-bit system. It also adds back various switch default clauses
-    for GCC; GCC errors out if they are not present (with an appropriately
-    high level of warnings).
-  Safely convert num_bytes to a png_byte in png_set_sig_bytes() (Robert
-    Seacord).
-  Fixed the recently reported 1's complement security issue by replacing
-    the value that is illegal in the PNG spec, in both signed and unsigned
-    values, with 0. Illegal unsigned values (anything greater than or equal
-    to  0x80000000) can still pass through, but since these are not illegal
-    in ANSI-C (unlike 0x80000000 in the signed case) the checking that
-    occurs later can catch them (John Bowler).
-
-Version 1.6.19beta03 [September 26, 2015]
-  Fixed png_save_int_32 when int is not 2's complement (John Bowler).
-  Updated libpng16 with all the recent test changes from libpng17,
-    including changes to pngvalid.c to ensure that the original,
-    distributed, version of contrib/visupng/cexcept.h can be used
-    (John Bowler).
-  pngvalid contains the correction to the use of SAVE/STORE_
-    UNKNOWN_CHUNKS; a bug revealed by changes in libpng 1.7. More
-    tests contain the --strict option to detect warnings and the
-    pngvalid-standard test has been corrected so that it does not
-    turn on progressive-read. There is a separate test which does
-    that. (John Bowler)
-  Also made some signed/unsigned fixes.
-  Make pngstest error limits version specific. Splitting the machine
-    generated error structs out to a file allows the values to be updated
-    without changing pngstest.c itself. Since libpng 1.6 and 1.7 have
-    slightly different error limits this simplifies maintenance. The
-    makepngs.sh script has also been updated to more accurately reflect
-    current problems in libpng 1.7 (John Bowler).
-  Incorporated new test PNG files into make check.  tests/pngstest-*
-    are changed so that the new test files are divided into 8 groups by
-    gamma and alpha channel.  These tests have considerably better code
-    and pixel-value coverage than contrib/pngsuite; however,coverage is
-    still incomplete (John Bowler).
-  Removed the '--strict' in 1.6 because of the double-gamma-correction
-    warning, updated pngstest-errors.h for the errors detected with the
-    new contrib/testspngs PNG test files (John Bowler).
-
-Version 1.6.19beta04 [October 15, 2015]
-  Worked around rgb-to-gray issues in libpng 1.6.  The previous
-    attempts to ignore the errors in the code aren't quite enough to
-    deal with the 'channel selection' encoding added to libpng 1.7; abort.
-    pngvalid.c is changed to drop this encoding in prior versions.
-  Fixed 'pow' macros in pngvalid.c. It is legal for 'pow' to be a
-    macro, therefore the argument list cannot contain preprocessing
-    directives.  Make sure pow is a function where this happens. This is
-    a minimal safe fix, the issue only arises in non-performance-critical
-    code (bug report by Curtis Leach, fix by John Bowler).
-  Added sPLT support to pngtest.c
-
-Version 1.6.19rc01 [October 23, 2015]
-  No changes.
-
-Version 1.6.19rc02 [October 31, 2015]
-  Prevent setting or writing over-length PLTE chunk (Cosmin Truta).
-  Silently truncate over-length PLTE chunk while reading.
-  Libpng incorrectly calculated the output rowbytes when the application
-    decreased either the number of channels or the bit depth (or both) in
-    a user transform.  This was safe; libpng overallocated buffer space
-   (potentially by quite a lot; up to 4 times the amount required) but,
-   from 1.5.4 on, resulted in a png_error (John Bowler).
-
-Version 1.6.19rc03 [November 3, 2015]
-  Fixed some inconsequential cut-and-paste typos in png_set_cHRM_XYZ_fixed().
-  Clarified COPYRIGHT information to state explicitly that versions
-    are derived from previous versions.
-  Removed much of the long list of previous versions from png.h and
-    libpng.3.
-
-Version 1.6.19rc04 [November 5, 2015]
-  Fixed new bug with CRC error after reading an over-length palette
-    (bug report by Cosmin Truta) (CVE-2015-8126).
-
-Version 1.6.19 [November 12, 2015]
-  Cleaned up coding style in png_handle_PLTE().
-
-Version 1.6.20beta01 [November 20, 2015]
-  Avoid potential pointer overflow/underflow in png_handle_sPLT() and
-    png_handle_pCAL() (Bug report by John Regehr).
-
-Version 1.6.20beta02 [November 23, 2015]
-  Fixed incorrect implementation of png_set_PLTE() that uses png_ptr
-    not info_ptr, that left png_set_PLTE() open to the CVE-2015-8126
-    vulnerability.
-
-Version 1.6.20beta03 [November 24, 2015]
-  Backported tests from libpng-1.7.0beta69.
-
-Version 1.6.20rc01 [November 26, 2015]
-  Fixed an error in handling of bad zlib CMINFO field in pngfix, found by
-    American Fuzzy Lop, reported by Brian Carpenter.  inflate() doesn't
-    immediately fault a bad CMINFO field; instead a 'too far back' error
-    happens later (at least some times).  pngfix failed to limit CMINFO to
-    the allowed values but then assumed that window_bits was in range,
-    triggering an assert. The bug is mostly harmless; the PNG file cannot
-    be fixed.
-
-Version 1.6.20rc02 [November 29, 2015]
-  In libpng 1.6 zlib initialization was changed to use the window size
-    in the zlib stream, not a fixed value. This causes some invalid images,
-    where CINFO is too large, to display 'correctly' if the rest of the
-    data is valid.  This provides a workaround for zlib versions where the
-    error arises (ones that support the API change to use the window size
-    in the stream).
-
-Version 1.6.20 [December 3, 2015]
-  No changes.
-
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,7 @@ enable_testing()

 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 6)
-set(PNGLIB_RELEASE 20)
+set(PNGLIB_RELEASE 18)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})

@@ -261,7 +261,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
  set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.20
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.18rc01
    VERSION 16.${PNGLIB_RELEASE}.0
    SOVERSION 16
    CLEAN_DIRECT_OUTPUT 1)
--- a/39
+++ b/39
@@ -10,11 +10,10 @@ this sentence.

 This code is released under the libpng license.

-libpng versions 1.0.7, July 1, 2000, through 1.6.20, December 3, 2015, are
-Copyright (c) 2000-2002, 2004, 2006-2015 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:
+libpng versions 1.0.7, July 1, 2000, through 1.6.18rc01, July 9, 2015, are
+Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.0.6
+with the following individuals added to the list of Contributing Authors

   Simon-Pierre Cadieux
   Eric S. Raymond
@@ -33,20 +32,18 @@ and with the following additions to the disclaimer:
   the user.

 libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
-Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
-libpng-0.96, and are distributed according to the same disclaimer and
-license as libpng-0.96, with the following individuals added to the list
-of Contributing Authors:
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are distributed according
+to the same disclaimer and license as libpng-0.96, with the following
+individuals added to the list of Contributing Authors:

   Tom Lane
   Glenn Randers-Pehrson
   Willem van Schaik

 libpng versions 0.89, June 1996, through 0.96, May 1997, are
-Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
-and are distributed according to the same disclaimer and license as
-libpng-0.88, with the following individuals added to the list of
-Contributing Authors:
+Copyright (c) 1996-1997 Andreas Dilger, and are
+distributed according to the same disclaimer and license as libpng-0.90,
+with the following individuals added to the list of Contributing Authors:

   John Bowler
   Kevin Bracey
@@ -79,13 +76,13 @@ Permission is hereby granted to use, copy, modify, and distribute this
 source code, or portions hereof, for any purpose, without fee, subject
 to the following restrictions:

-  1. The origin of this source code must not be misrepresented.
+1. The origin of this source code must not be misrepresented.

-  2. Altered versions must be plainly marked as such and must not
-     be misrepresented as being the original source.
+2. Altered versions must be plainly marked as such and must not
+   be misrepresented as being the original source.

-  3. This Copyright notice may not be removed or altered from any
-     source or altered source distribution.
+3. This Copyright notice may not be removed or altered from any
+   source or altered source distribution.

 The Contributing Authors and Group 42, Inc. specifically permit, without
 fee, and encourage the use of this source code as a component to
@@ -93,12 +90,10 @@ supporting the PNG file format in commercial products.  If you use this
 source code in a product, acknowledgment is not required but would be
 appreciated.

-END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
-
 A "png_get_copyright" function is available, for convenient use in "about"
 boxes and the like:

-   printf("%s", png_get_copyright(NULL));
+   printf("%s",png_get_copyright(NULL));

 Also, the PNG logo (in PNG format, of course) is supplied in the
 files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
@@ -109,4 +104,4 @@ the additional disclaimers inserted at version 1.0.7.

 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-December 3, 2015
+July 9, 2015
--- a/Makefile.am
+++ b/Makefile.am
@@ -51,17 +51,23 @@ TESTS =\
   tests/pngvalid-gamma-expand16-background\
   tests/pngvalid-gamma-expand16-transform tests/pngvalid-gamma-sbit\
   tests/pngvalid-gamma-threshold tests/pngvalid-gamma-transform\
-   tests/pngvalid-progressive-size\
+   tests/pngvalid-progressive-interlace-size\
   tests/pngvalid-progressive-interlace-standard\
-   tests/pngvalid-transform\
+   tests/pngvalid-progressive-interlace-transform\
   tests/pngvalid-progressive-standard tests/pngvalid-standard\
-   tests/pngstest-1.8 tests/pngstest-1.8-alpha tests/pngstest-linear\
-   tests/pngstest-linear-alpha tests/pngstest-none tests/pngstest-none-alpha\
-   tests/pngstest-sRGB tests/pngstest-sRGB-alpha tests/pngunknown-IDAT\
+   tests/pngstest-0g01 tests/pngstest-0g02 tests/pngstest-0g04\
+   tests/pngstest-0g08 tests/pngstest-0g16 tests/pngstest-2c08\
+   tests/pngstest-2c16 tests/pngstest-3p01 tests/pngstest-3p02\
+   tests/pngstest-3p04 tests/pngstest-3p08 tests/pngstest-4a08\
+   tests/pngstest-4a16 tests/pngstest-6a08 tests/pngstest-6a16\
+   tests/pngstest-error tests/pngunknown-IDAT\
   tests/pngunknown-discard tests/pngunknown-if-safe tests/pngunknown-sAPI\
   tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg\
   tests/pngimage-quick tests/pngimage-full

+# These tests are expected, and required, to fail:
+XFAIL_TESTS = tests/pngstest-error
+
 # man pages
 dist_man_MANS= libpng.3 libpngpf.3 png.5

--- a/2
+++ b/2
@@ -1,4 +1,4 @@
-README for libpng version 1.6.20 - December 3, 2015 (shared library 16.0)
+README for libpng version 1.6.18rc01 - July 9, 2015 (shared library 16.0)
 See the note about version numbers near the top of png.h

 See INSTALL for instructions on how to install libpng.
--- a/autogen.sh
+++ b/autogen.sh
@@ -74,12 +74,12 @@ done
 #
 # The autotools generated files:
 libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in
-   config.sub configure depcomp install-sh ltmain.sh missing\
+   config.h.in~ config.sub configure depcomp install-sh ltmain.sh missing\
   test-driver"
 #
 # Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
 # versions than those required by configure.ac):
-libpng_autotools_extra="compile config.h.in~"
+libpng_autotools_extra="compile"
 #
 # These are separate because 'maintainer-clean' does not remove them.
 libpng_libtool_files="scripts/libtool.m4 scripts/ltoptions.m4\
--- a/configure.ac
+++ b/configure.ac
@@ -18,7 +18,7 @@ AC_PREREQ([2.68])

 dnl Version number stuff here:

-AC_INIT([libpng],[1.6.20],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.18rc01],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])

 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -39,10 +39,10 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake

-PNGLIB_VERSION=1.6.20
+PNGLIB_VERSION=1.6.18rc01
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=20
+PNGLIB_RELEASE=18

 dnl End of version number stuff

--- a/contrib/README.txt
+++ b/contrib/README.txt
@@ -1,5 +1,4 @@

 This "contrib" directory contains contributions which are not necessarily under
 the libpng license, although all are open source.  They are not part of
-libpng proper and are not used for building the library, although some are used
-for testing the library via "make check".
+libpng proper and are not used for building the library.
--- a/contrib/arm-neon/linux-auxv.c
+++ b/contrib/arm-neon/linux-auxv.c
@@ -7,7 +7,7 @@
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
 * and license in png.h
- *
+ * 
 * SEE contrib/arm-neon/README before reporting bugs
 *
 * STATUS: COMPILED, TESTED
--- a/contrib/arm-neon/linux.c
+++ b/contrib/arm-neon/linux.c
@@ -72,7 +72,7 @@ png_have_neon(png_structp png_ptr)
                     state = Colon;
                  break;
               }
-
+               
               /* did not match 'feature' */
               state = SkipLine;
               /* FALL THROUGH */
--- a/contrib/examples/pngpixel.c
+++ b/contrib/examples/pngpixel.c
@@ -87,7 +87,7 @@ print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
       */
      case PNG_COLOR_TYPE_PALETTE:
         {
-            PNG_CONST int index = component(row, x, 0, bit_depth, 1);
+            PNG_CONST unsigned int index = component(row, x, 0, bit_depth, 1);
            png_colorp palette = NULL;
            int num_palette = 0;

--- a/contrib/examples/simpleover.c
+++ b/contrib/examples/simpleover.c
@@ -136,7 +136,7 @@ sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
            /* This is the optimized Porter-Duff 'Over' operation, when the
             * input alpha is 0 the output is not changed.
             */
-            if (in_alpha > 0)
+            if (in_alpha > 0) 
            {
               png_uint_16 *out_pixel = sprite->buffer +
                  ((y+y_offset) * sprite->width + (x+x_offset))*4;
@@ -184,7 +184,7 @@ sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
   }
 }

-static int
+static int 
 create_sprite(struct sprite *sprite, int *argc, const char ***argv)
 {
   /* Read the arguments and create this sprite. The sprite buffer has already
@@ -415,7 +415,7 @@ simpleover_process(png_imagep output, png_bytep out_buf, int argc,
            n = sscanf(argv[0], "--sprite=%u,%u,%" str(sprite_name_chars) "s%c",
                &sprites[nsprites].width, &sprites[nsprites].height,
                sprites[nsprites].name, &tombstone);
-
+            
            if ((n == 2 || n == 3) &&
                sprites[nsprites].width > 0 && sprites[nsprites].height > 0)
            {
@@ -492,7 +492,7 @@ simpleover_process(png_imagep output, png_bytep out_buf, int argc,
               if (!add_sprite(output, out_buf, sprites+isprite, &argc, &argv))
                  goto out; /* error in add_sprite */

-               break;
+               break; 
            }
         }

--- a/contrib/gregbook/readpng2.c
+++ b/contrib/gregbook/readpng2.c
@@ -4,7 +4,7 @@

  ---------------------------------------------------------------------------

-      Copyright (c) 1998-2015 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.

      This software is provided "as is," without warranty of any kind,
      express or implied.  In no event shall the author or contributors
@@ -51,11 +51,6 @@
      along with this program; if not, write to the Free Software Foundation,
      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

-  ---------------------------------------------------------------------------
-
-   Changelog:
-     %RDATE% - Check return value of png_get_bKGD() (Glenn R-P)
-
  ---------------------------------------------------------------------------*/


@@ -266,38 +261,36 @@ static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
    /* since we know we've read all of the PNG file's "header" (i.e., up
     * to IDAT), we can check for a background color here */

-    if (mainprog_ptr->need_bgcolor)
+    if (mainprog_ptr->need_bgcolor &&
+        png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
    {
        png_color_16p pBackground;

        /* it is not obvious from the libpng documentation, but this function
         * takes a pointer to a pointer, and it always returns valid red,
         * green and blue values, regardless of color_type: */
-        if (png_get_bKGD(png_ptr, info_ptr, &pBackground))
-        {
+        png_get_bKGD(png_ptr, info_ptr, &pBackground);

-           /* however, it always returns the raw bKGD data, regardless of any
-            * bit-depth transformations, so check depth and adjust if necessary
-            */
-           if (bit_depth == 16) {
-               mainprog_ptr->bg_red   = pBackground->red   >> 8;
-               mainprog_ptr->bg_green = pBackground->green >> 8;
-               mainprog_ptr->bg_blue  = pBackground->blue  >> 8;
-           } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
-               if (bit_depth == 1)
-                   mainprog_ptr->bg_red = mainprog_ptr->bg_green =
-                     mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
-               else if (bit_depth == 2)
-                   mainprog_ptr->bg_red = mainprog_ptr->bg_green =
-                     mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
-               else /* bit_depth == 4 */
-                   mainprog_ptr->bg_red = mainprog_ptr->bg_green =
-                     mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
-           } else {
-               mainprog_ptr->bg_red   = (uch)pBackground->red;
-               mainprog_ptr->bg_green = (uch)pBackground->green;
-               mainprog_ptr->bg_blue  = (uch)pBackground->blue;
-           }
+        /* however, it always returns the raw bKGD data, regardless of any
+         * bit-depth transformations, so check depth and adjust if necessary */
+        if (bit_depth == 16) {
+            mainprog_ptr->bg_red   = pBackground->red   >> 8;
+            mainprog_ptr->bg_green = pBackground->green >> 8;
+            mainprog_ptr->bg_blue  = pBackground->blue  >> 8;
+        } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+            if (bit_depth == 1)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
+            else if (bit_depth == 2)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
+            else /* bit_depth == 4 */
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
+        } else {
+            mainprog_ptr->bg_red   = (uch)pBackground->red;
+            mainprog_ptr->bg_green = (uch)pBackground->green;
+            mainprog_ptr->bg_blue  = (uch)pBackground->blue;
        }
    }

--- a/contrib/gregbook/rpng2-win.c
+++ b/contrib/gregbook/rpng2-win.c
@@ -33,7 +33,7 @@
    - 2.02:  fixed improper display of usage screen on PNG error(s); fixed
              unexpected-EOF and file-read-error cases
    - 2.03:  removed runtime MMX-enabling/disabling and obsolete -mmx* options
-    - 2.04:
+    - 2.04:  
             (GR-P)

  ---------------------------------------------------------------------------
--- a/contrib/gregbook/rpng2-x.c
+++ b/contrib/gregbook/rpng2-x.c
@@ -43,10 +43,12 @@
    - 2.03:  deleted runtime MMX-enabling/disabling and obsolete -mmx* options
    - 2.04:  Added "void(foo);" statements to quiet pedantic compiler warnings
             about unused variables (GR-P)
-    - 2.05:  Use nanosleep() instead of usleep(), which is deprecated (GR-P).
+
+  TO DO:
+             use nanosleep() instead of usleep(), which is obsolete/deprecated.
  ---------------------------------------------------------------------------

-      Copyright (c) 1998-2010, 2014-2015 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.

      This software is provided "as is," without warranty of any kind,
      express or implied.  In no event shall the author or contributors
@@ -117,7 +119,6 @@
 # undef usleep
 # define usleep(usec) {        \
   struct timespec ts;         \
-   ts.tv_sec = 0;              \
   ts.tv_nsec = (usec) * 1000; \
   nanosleep(&ts, NULL); }
 #  endif
@@ -496,12 +497,12 @@ int main(int argc, char **argv)
          "\t\t  transparent images; overrides -bgcolor\n",
          num_bgpat-1);
 #ifdef FEATURE_LOOP
-        fprintf(stderr,
+        fprintf(stderr, 
          "    -loop\tloops through background images after initial display\n"
          "\t\t  is complete (depends on -bgpat)\n"
          "    sec \tseconds to display each background image (default = 2)\n");
 #endif
-        fprintf(stderr,
+        fprintf(stderr, 
          "    dur \tduration in microseconds to wait after displaying each\n"
          "\t\t  row (for demo purposes)\n"
          "    -timing\tenables delay for every block read, to simulate modem\n"
--- a/contrib/libtests/fakepng.c
+++ b/contrib/libtests/fakepng.c
@@ -1,12 +1,4 @@
-/* Fake a PNG - just write it out directly.
- *
- * COPYRIGHT: Written by John Cunningham Bowler, 2014.
- * 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.
- *
- */
-
+/* Fake a PNG - just write it out directly. */
 #include <stdio.h>
 #include <zlib.h> /* for crc32 */

--- a/contrib/libtests/makepng.c
+++ b/contrib/libtests/makepng.c
@@ -1,9 +1,8 @@
-/* makepng.c */
-#define _ISOC99_SOURCE
-/* Copyright: */
-#define COPYRIGHT "\251 2013,2015 John Cunningham Bowler"
-/*
- * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+/* makepng.c
+ *
+ * Copyright (c) 2013 John Cunningham Bowler
+ *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
@@ -11,8 +10,8 @@
 *
 * Make a test PNG image.  The arguments are as follows:
 *
- *    makepng [--sRGB|--linear|--1.8] [--tRNS] [--nofilters] \
- *       color-type bit-depth [file-name]
+ *  makepng [--sRGB|--linear|--1.8] [--color=<color>] color-type bit-depth \
+ *      [file-name]
 *
 * The color-type may be numeric (and must match the numbers used by the PNG
 * specification) or one of the format names listed below.  The bit-depth is the
@@ -40,8 +39,8 @@
 * 4 channels: linear combinations of, from the top-left corner clockwise,
 *    transparent, red, green, blue.
 *
- * For color-mapped images a four channel color-map is used and if --tRNS is
- * given the PNG file has a tRNS chunk, as follows:
+ * For color-mapped images a four channel color-map is used and the PNG file has
+ * a tRNS chunk, as follows:
 *
 * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white
 * 2-bit: entry 0: transparent-green
@@ -54,9 +53,6 @@
 * The palette always has 2^bit-depth entries and the tRNS chunk one fewer.  The
 * image is the 1-channel diamond, but using palette index, not luminosity.
 *
- * For formats other than color-mapped ones if --tRNS is specified a tRNS chunk
- * is generated with all channels equal to the low bits of 0x0101.
- *
 * Image size is determined by the final pixel depth in bits, i.e. channels x
 * bit-depth, as follows:
 *
@@ -64,64 +60,20 @@
 * 16 bits:           256x256
 * More than 16 bits: 1024x1024
 *
- * Row filtering is the libpng default but may be turned off (the 'none' filter
- * is used on every row) with the --nofilters option.
- *
- * The images are not interlaced.
- *
- * If file-name is given then the PNG is written to that file, else it is
- * written to stdout.  Notice that stdout is not supported on systems where, by
- * default, it assumes text output; this program makes no attempt to change the
- * text mode of stdout!
- *
- *    makepng --color=<color> ...
+ * Row filtering is turned off (the 'none' filter is used on every row) and the
+ * images are not interlaced.
 *
 * If --color is given then the whole image has that color, color-mapped images
 * will have exactly one palette entry and all image files with be 16x16 in
 * size.  The color value is 1 to 4 decimal numbers as appropriate for the color
 * type.
 *
- *    makepng --small ...
- *
- * If --small is given the images are no larger than required to include every
- * possible pixel value for the format.
- *
- * For formats with pixels 8 bits or fewer in size the images consist of a
- * single row with 2^pixel-depth pixels, one of every possible value.
- *
- * For formats with 16-bit pixels a 256x256 image is generated containing every
- * possible pixel value.
- *
- * For larger pixel sizes a 256x256 image is generated where the first row
- * consists of each pixel that has identical byte values throughout the pixel
- * followed by rows where the byte values differ within the pixel.
- *
- * In all cases the pixel values are arranged in such a way that the SUB and UP
- * filters give byte sequences for maximal zlib compression.  By default (if
- * --nofilters is not given) the SUB filter is used on the first row and the UP
- * filter on all following rows.
- *
- * The --small option is meant to provide good test-case coverage, however the
- * images are not easy to examine visually.  Without the --small option the
- * images contain identical color values; the pixel values are adjusted
- * according to the gamma encoding with no gamma encoding being interpreted as
- * sRGB.
- *
- * LICENSING
- * =========
- *
- * This code is copyright of the authors, see the COPYRIGHT define above.  The
- * code is licensed as above, using the libpng license.  The code generates
- * images which are solely the product of the code; the options choose which of
- * the many possibilities to generate.  The images that result (but not the code
- * which generates them) are licensed as defined here:
- *
- * IMPORTANT: the COPYRIGHT #define must contain ISO-Latin-1 characters, the
- * IMAGE_LICENSING #define must contain UTF-8 characters.  The 'copyright'
- * symbol 0xA9U (\251) in ISO-Latin-1 encoding and 0xC20xA9 (\302\251) in UTF-8.
+ * If file-name is given then the PNG is written to that file, else it is
+ * written to stdout.  Notice that stdout is not supported on systems where, by
+ * default, it assumes text output; this program makes no attempt to change the
+ * text mode of stdout!
 */
-#define IMAGE_LICENSING "Dedicated to the public domain per Creative Commons "\
-    "license \"CC0 1.0\"; https://creativecommons.org/publicdomain/zero/1.0/"
+#define _ISOC99_SOURCE /* for strtoull */

 #include <stddef.h> /* for offsetof */
 #include <stdlib.h>
@@ -130,8 +82,6 @@
 #include <ctype.h>
 #include <math.h>
 #include <errno.h>
-#include <assert.h>
-#include <stdint.h>

 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
 #  include <config.h>
@@ -146,25 +96,6 @@
 #  include "../../png.h"
 #endif

-#include <zlib.h>
-
-/* Work round for GCC complaints about casting a (double) function result to
- * an unsigned:
- */
-static unsigned int
-flooru(double d)
-{
-   d = floor(d);
-   return (unsigned int)d;
-}
-
-static png_byte
-floorb(double d)
-{
-   d = floor(d);
-   return (png_byte)d;
-}
-
 /* This structure is used for inserting extra chunks (the --insert argument, not
 * documented above.)
 */
@@ -176,7 +107,7 @@ typedef struct chunk_insert
   png_charp            parameters[1];
 } chunk_insert;

-static unsigned int
+static int
 channels_of_type(int color_type)
 {
   if (color_type & PNG_COLOR_MASK_PALETTE)
@@ -197,15 +128,14 @@ channels_of_type(int color_type)
   }
 }

-static unsigned int
+static int
 pixel_depth_of_type(int color_type, int bit_depth)
 {
   return channels_of_type(color_type) * bit_depth;
 }

 static unsigned int
-image_size_of_type(int color_type, int bit_depth, unsigned int *colors,
-   int small)
+image_size_of_type(int color_type, int bit_depth, unsigned int *colors)
 {
   if (*colors)
      return 16;
@@ -214,16 +144,7 @@ image_size_of_type(int color_type, int bit_depth, unsigned int *colors,
   {
      int pixel_depth = pixel_depth_of_type(color_type, bit_depth);

-      if (small)
-      {
-         if (pixel_depth <= 8) /* there will be one row */
-            return 1 << pixel_depth;
-
-         else
-            return 256;
-      }
-
-      else if (pixel_depth < 8)
+      if (pixel_depth < 8)
         return 64;

      else if (pixel_depth > 16)
@@ -296,8 +217,7 @@ generate_palette(png_colorp palette, png_bytep trans, int bit_depth,
         else
         {
            unsigned int size = 1U << (bit_depth/2); /* 2, 4 or 16 */
-            unsigned int x, y;
-            volatile unsigned int ip = 0;
+            unsigned int x, y, ip;

            for (x=0; x<size; ++x) for (y=0; y<size; ++y)
            {
@@ -361,7 +281,7 @@ set_value(png_bytep row, size_t rowbytes, png_uint_32 x, unsigned int bit_depth,
               exit(1);

            case 16:
-               value = flooru(65535*pow(value/65535.,conv)+.5);
+               value = (unsigned int)floor(65535*pow(value/65535.,conv)+.5);
               *row++ = (png_byte)(value >> 8);
               *row = (png_byte)value;
               return;
@@ -386,148 +306,15 @@ set_value(png_bytep row, size_t rowbytes, png_uint_32 x, unsigned int bit_depth,
   }
 }

-static int /* filter mask for row */
+static void
 generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
   int bit_depth, png_const_bytep gamma_table, double conv,
-   unsigned int *colors, int small)
+   unsigned int *colors)
 {
-   int filters = 0; /* file *MASK*, 0 means the default, not NONE */
-   png_uint_32 size_max =
-      image_size_of_type(color_type, bit_depth, colors, small)-1;
+   png_uint_32 size_max = image_size_of_type(color_type, bit_depth, colors)-1;
   png_uint_32 depth_max = (1U << bit_depth)-1; /* up to 65536 */

-   if (colors[0] == 0) if (small)
-   {
-      unsigned int pixel_depth = pixel_depth_of_type(color_type, bit_depth);
-
-      /* For pixel depths less than 16 generate a single row containing all the
-       * possible pixel values.  For 16 generate all 65536 byte pair
-       * combinations in a 256x256 pixel array.
-       */
-      switch (pixel_depth)
-      {
-         case 1:
-            assert(y == 0 && rowbytes == 1 && size_max == 1);
-            row[0] = 0x6CU; /* binary: 01101100, only top 2 bits used */
-            filters = PNG_FILTER_NONE;
-            break;
-
-         case 2:
-            assert(y == 0 && rowbytes == 1 && size_max == 3);
-            row[0] = 0x1BU; /* binary 00011011, all bits used */
-            filters = PNG_FILTER_NONE;
-            break;
-
-         case 4:
-            assert(y == 0 && rowbytes == 8 && size_max == 15);
-            row[0] = 0x01U;
-            row[1] = 0x23U; /* SUB gives 0x22U for all following bytes */
-            row[2] = 0x45U;
-            row[3] = 0x67U;
-            row[4] = 0x89U;
-            row[5] = 0xABU;
-            row[6] = 0xCDU;
-            row[7] = 0xEFU;
-            filters = PNG_FILTER_SUB;
-            break;
-
-         case 8:
-            /* The row will have all the pixel values in order starting with
-             * '1', the SUB filter will change every byte into '1' (including
-             * the last, which generates pixel value '0').  Since the SUB filter
-             * has value 1 this should result in maximum compression.
-             */
-            assert(y == 0 && rowbytes == 256 && size_max == 255);
-            for (;;)
-            {
-               row[size_max] = 0xFFU & (size_max+1);
-               if (size_max == 0)
-                  break;
-               --size_max;
-            }
-            filters = PNG_FILTER_SUB;
-            break;
-
-         case 16:
-            /* Rows are generated such that each row has a constant difference
-             * between the first and second byte of each pixel and so that the
-             * difference increases by 1 at each row.  The rows start with the
-             * first byte value of 0 and the value increases to 255 across the
-             * row.
-             *
-             * The difference starts at 1, so the first row is:
-             *
-             *     0 1 1 2 2 3 3 4 ... 254 255 255 0
-             *
-             * This means that running the SUB filter on the first row produces:
-             *
-             *   [SUB==1] 0 1 0 1 0 1...
-             *
-             * Then the difference is 2 on the next row, giving:
-             *
-             *    0 2 1 3 2 4 3 5 ... 254 0 255 1
-             *
-             * When the UP filter is run on this libpng produces:
-             *
-             *   [UP ==2] 0 1 0 1 0 1...
-             *
-             * And so on for all the remain rows to the final two * rows:
-             *
-             *    row 254: 0 255 1 0 2 1 3 2 4 3 ... 254 253 255 254
-             *    row 255: 0   0 1 1 2 2 3 3 4 4 ... 254 254 255 255
-             */
-            assert(rowbytes == 512 && size_max == 255);
-            for (;;)
-            {
-               row[2*size_max  ] = 0xFFU & size_max;
-               row[2*size_max+1] = 0xFFU & (size_max+y+1);
-               if (size_max == 0)
-                  break;
-               --size_max;
-            }
-            /* The first row must include PNG_FILTER_UP so that libpng knows we
-             * need to keep it for the following row:
-             */
-            filters = (y == 0 ? PNG_FILTER_SUB+PNG_FILTER_UP : PNG_FILTER_UP);
-            break;
-
-         case 24:
-         case 32:
-         case 48:
-         case 64:
-            /* The rows are filled by an alogorithm similar to the above, in the
-             * first row pixel bytes are all equal, increasing from 0 by 1 for
-             * each pixel.  In the second row the bytes within a pixel are
-             * incremented 1,3,5,7,... from the previous row byte.  Using an odd
-             * number ensures all the possible byte values are used.
-             */
-            assert(size_max == 255 && rowbytes == 256*(pixel_depth>>3));
-            pixel_depth >>= 3; /* now in bytes */
-            while (rowbytes > 0)
-            {
-               const size_t pixel_index = --rowbytes/pixel_depth;
-
-               if (y == 0)
-                  row[rowbytes] = 0xFFU & pixel_index;
-
-               else
-               {
-                  const size_t byte_offset =
-                     rowbytes - pixel_index * pixel_depth;
-
-                  row[rowbytes] =
-                     0xFFU & (pixel_index + (byte_offset * 2*y) + 1);
-               }
-            }
-            filters = (y == 0 ? PNG_FILTER_SUB+PNG_FILTER_UP : PNG_FILTER_UP);
-            break;
-
-         default:
-            assert(0/*NOT REACHED*/);
-      }
-   }
-
-   else switch (channels_of_type(color_type))
+   if (colors[0] == 0) switch (channels_of_type(color_type))
   {
   /* 1 channel: a square image with a diamond, the least luminous colors are on
    *    the edge of the image, the most luminous in the center.
@@ -739,8 +526,6 @@ generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type,
         colors[0], channels_of_type(color_type));
      exit(1);
   }
-
-   return filters;
 }


@@ -769,7 +554,7 @@ makepng_error(png_structp png_ptr, png_const_charp message)
 static int /* 0 on success, else an error code */
 write_png(const char **name, FILE *fp, int color_type, int bit_depth,
   volatile png_fixed_point gamma, chunk_insert * volatile insert,
-   unsigned int filters, unsigned int *colors, int small, int tRNS)
+   unsigned int filters, unsigned int *colors)
 {
   png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
      name, makepng_error, makepng_warning);
@@ -796,15 +581,6 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,

   /* Allow benign errors so that we can write PNGs with errors */
   png_set_benign_errors(png_ptr, 1/*allowed*/);
-
-   /* Max out the text compression level in an attempt to make the license
-    * small.   If --small then do the same for the IDAT.
-    */
-   if (small)
-      png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
-
-   png_set_text_compression_level(png_ptr, Z_BEST_COMPRESSION);
-
   png_init_io(png_ptr, fp);

   info_ptr = png_create_info_struct(png_ptr);
@@ -812,37 +588,11 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,
      png_error(png_ptr, "OOM allocating info structure");

   {
-      const unsigned int size =
-         image_size_of_type(color_type, bit_depth, colors, small);
-      unsigned int ysize;
+      unsigned int size = image_size_of_type(color_type, bit_depth, colors);
      png_fixed_point real_gamma = 45455; /* For sRGB */
      png_byte gamma_table[256];
      double conv;

-      /* Normally images are square, but with 'small' we want to simply generate
-       * all the pixel values, or all that we reasonably can:
-       */
-      if (small)
-      {
-         const unsigned int pixel_depth =
-            pixel_depth_of_type(color_type, bit_depth);
-
-         if (pixel_depth <= 8U)
-         {
-            assert(size == (1U<<pixel_depth));
-            ysize = 1U;
-         }
-
-         else
-         {
-            assert(size == 256U);
-            ysize = 256U;
-         }
-      }
-
-      else
-         ysize = size;
-
      /* This function uses the libpng values used on read to carry extra
       * information about the gamma:
       */
@@ -875,13 +625,13 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,
            gamma_table[0] = 0;

            for (i=1; i<255; ++i)
-               gamma_table[i] = floorb(pow(i/255.,conv) * 255 + .5);
+               gamma_table[i] = (png_byte)floor(pow(i/255.,conv) * 255 + .5);

            gamma_table[255] = 255;
         }
      }

-      png_set_IHDR(png_ptr, info_ptr, size, ysize, bit_depth, color_type,
+      png_set_IHDR(png_ptr, info_ptr, size, size, bit_depth, color_type,
         PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);

      if (color_type & PNG_COLOR_MASK_PALETTE)
@@ -893,26 +643,14 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,
         npalette = generate_palette(palette, trans, bit_depth, gamma_table,
            colors);
         png_set_PLTE(png_ptr, info_ptr, palette, npalette);
-
-         if (tRNS)
-            png_set_tRNS(png_ptr, info_ptr, trans, npalette-1,
-               NULL/*transparent color*/);
+         png_set_tRNS(png_ptr, info_ptr, trans, npalette-1,
+            NULL/*transparent color*/);

         /* Reset gamma_table to prevent the image rows being changed */
         for (npalette=0; npalette<256; ++npalette)
            gamma_table[npalette] = (png_byte)npalette;
      }

-      else if (tRNS)
-      {
-         png_color_16 col;
-
-         col.red = col.green = col.blue = col.gray =
-            0x0101U & ((1U<<bit_depth)-1U);
-         col.index = 0U;
-         png_set_tRNS(png_ptr, info_ptr, NULL/*trans*/, 1U, &col);
-      }
-
      if (gamma == PNG_DEFAULT_sRGB)
         png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE);

@@ -944,11 +682,7 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,
      png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, filters);

      {
-#        ifdef PNG_WRITE_INTERLACING_SUPPORTED
-            int passes = png_set_interlace_handling(png_ptr);
-#        else /* !WRITE_INTERLACING */
-            int passes = 1;
-#        endif /* !WRITE_INTERLACING */
+         int passes = png_set_interlace_handling(png_ptr);
         int pass;
         png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);

@@ -961,15 +695,10 @@ write_png(const char **name, FILE *fp, int color_type, int bit_depth,
         {
            unsigned int y;

-            for (y=0; y<ysize; ++y)
+            for (y=0; y<size; ++y)
            {
-               unsigned int row_filters =
-                  generate_row(row, rowbytes, y, color_type, bit_depth,
-                        gamma_table, conv, colors, small);
-
-               if (row_filters != 0 && filters == PNG_ALL_FILTERS)
-                  png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, row_filters);
-
+               generate_row(row, rowbytes, y, color_type, bit_depth,
+                  gamma_table, conv, colors);
               png_write_row(png_ptr, row);
            }
         }
@@ -1098,7 +827,7 @@ static png_size_t
 load_fake(png_charp param, png_bytepp profile)
 {
   char *endptr = NULL;
-   uint64_t size = strtoull(param, &endptr, 0/*base*/);
+   unsigned long long int size = strtoull(param, &endptr, 0/*base*/);

   /* The 'fake' format is <number>*[string] */
   if (endptr != NULL && *endptr == '*')
@@ -1333,8 +1062,7 @@ insert_iTXt(png_structp png_ptr, png_infop info_ptr, int nparams,
 }

 static void
-insert_hIST(png_structp png_ptr, png_infop info_ptr, int nparams,
-      png_charpp params)
+insert_hIST(png_structp png_ptr, png_infop info_ptr, int nparams, png_charpp params)
 {
   int i;
   png_uint_16 freq[256];
@@ -1361,56 +1089,6 @@ insert_hIST(png_structp png_ptr, png_infop info_ptr, int nparams,
   png_set_hIST(png_ptr, info_ptr, freq);
 }

-static png_byte
-bval(png_const_structrp png_ptr, png_charp param, unsigned int maxval)
-{
-   char *endptr = NULL;
-   unsigned long int l = strtoul(param, &endptr, 0/*base*/);
-
-   if (param[0] && *endptr == 0 && l <= maxval)
-      return (png_byte)l;
-
-   else
-      png_error(png_ptr, "sBIT: invalid sBIT value");
-}
-
-static void
-insert_sBIT(png_structp png_ptr, png_infop info_ptr, int nparams,
-      png_charpp params)
-{
-   const int ct = png_get_color_type(png_ptr, info_ptr);
-   const int c = (ct & PNG_COLOR_MASK_COLOR ? 3 : 1) +
-      (ct & PNG_COLOR_MASK_ALPHA ? 1 : 0);
-   const unsigned int maxval =
-      ct & PNG_COLOR_MASK_PALETTE ? 8U : png_get_bit_depth(png_ptr, info_ptr);
-   png_color_8 sBIT;
-
-   if (nparams != c)
-      png_error(png_ptr, "sBIT: incorrect parameter count");
-
-   if (ct & PNG_COLOR_MASK_COLOR)
-   {
-      sBIT.red = bval(png_ptr, params[0], maxval);
-      sBIT.green = bval(png_ptr, params[1], maxval);
-      sBIT.blue = bval(png_ptr, params[2], maxval);
-      sBIT.gray = 42;
-   }
-
-   else
-   {
-      sBIT.red = sBIT.green = sBIT.blue = 42;
-      sBIT.gray = bval(png_ptr, params[0], maxval);
-   }
-
-   if (ct & PNG_COLOR_MASK_ALPHA)
-      sBIT.alpha = bval(png_ptr, params[nparams-1], maxval);
-
-   else
-      sBIT.alpha = 42;
-
-   png_set_sBIT(png_ptr, info_ptr, &sBIT);
-}
-
 #if 0
 static void
 insert_sPLT(png_structp png_ptr, png_infop info_ptr, int nparams, png_charpp params)
@@ -1538,11 +1216,6 @@ find_insert(png_const_charp what, png_charp param)
            return make_insert(what, insert_hIST, nparams, parameter_list);
         break;

-      case CHUNK(115,66,73,84): /* sBIT */
-         if (nparams <= 4)
-            return make_insert(what, insert_sBIT, nparams, parameter_list);
-         break;
-
 #if 0
      case CHUNK(115,80,76,84):  /* sPLT */
         return make_insert(what, insert_sPLT, nparams, parameter_list);
@@ -1558,80 +1231,6 @@ find_insert(png_const_charp what, png_charp param)
   return NULL;
 }

-/* This is necessary because libpng expects writeable strings for things like
- * text chunks (maybe this should be fixed...)
- */
-static png_charp
-strstash(png_const_charp foo)
-{
-   /* The program indicates a memory allocation error by crashing, this is by
-    * design.
-    */
-   if (foo != NULL)
-   {
-      png_charp bar = malloc(strlen(foo)+1);
-      return strcpy(bar, foo);
-   }
-
-   return NULL;
-}
-
-static png_charp
-strstash_list(const png_const_charp *text)
-{
-   size_t foo = 0;
-   png_charp result, bar;
-   const png_const_charp *line = text;
-
-   while (*line != NULL)
-      foo += strlen(*line++);
-
-   result = bar = malloc(foo+1);
-
-   line = text;
-   while (*line != NULL)
-   {
-      foo = strlen(*line);
-      memcpy(bar, *line++, foo);
-      bar += foo;
-   }
-
-   *bar = 0;
-   return result;
-}
-
-/* These are used to insert Copyright and Licence fields, they allow the text to
- * have \n unlike the --insert option.
- */
-static chunk_insert *
-add_tEXt(const char *key, const png_const_charp *text)
-{
-   static char what[5] = { 116, 69, 88, 116, 0 };
-   png_charp parameter_list[3];
-
-   parameter_list[0] = strstash(key);
-   parameter_list[1] = strstash_list(text);
-   parameter_list[2] = NULL;
-
-   return make_insert(what, insert_tEXt, 2, parameter_list);
-}
-
-static chunk_insert *
-add_iTXt(const char *key, const char *language, const char *language_key,
-      const png_const_charp *text)
-{
-   static char what[5] = { 105, 84, 88, 116, 0 };
-   png_charp parameter_list[5];
-
-   parameter_list[0] = strstash(key);
-   parameter_list[1] = strstash(language);
-   parameter_list[2] = strstash(language_key);
-   parameter_list[3] = strstash_list(text);
-   parameter_list[4] = NULL;
-
-   return make_insert(what, insert_iTXt, 4, parameter_list);
-}
-
 /* This is a not-very-good parser for a sequence of numbers (including 0).  It
 * doesn't accept some apparently valid things, but it accepts all the sensible
 * combinations.
@@ -1681,8 +1280,6 @@ main(int argc, char **argv)
   const char *file_name = NULL;
   int color_type = 8; /* invalid */
   int bit_depth = 32; /* invalid */
-   int small = 0; /* make full size images */
-   int tRNS = 0; /* don't output a tRNS chunk */
   unsigned int colors[5];
   unsigned int filters = PNG_ALL_FILTERS;
   png_fixed_point gamma = 0; /* not set */
@@ -1695,18 +1292,6 @@ main(int argc, char **argv)
   {
      char *arg = *++argv;

-      if (strcmp(arg, "--small") == 0)
-      {
-         small = 1;
-         continue;
-      }
-
-      if (strcmp(arg, "--tRNS") == 0)
-      {
-         tRNS = 1;
-         continue;
-      }
-
      if (strcmp(arg, "--sRGB") == 0)
      {
         gamma = PNG_DEFAULT_sRGB;
@@ -1847,10 +1432,9 @@ main(int argc, char **argv)

   if (color_type == 8 || bit_depth == 32)
   {
-      fprintf(stderr, "usage: makepng [--small] [--sRGB|--linear|--1.8] "
+      fprintf(stderr, "usage: makepng [--sRGB|--linear|--1.8] "
         "[--color=...] color-type bit-depth [file-name]\n"
-         "  Make a test PNG file, by default writes to stdout.\n"
-         "  Other options are available, UTSL.\n");
+         "  Make a test PNG file, by default writes to stdout.\n");
      exit(1);
   }

@@ -1869,19 +1453,10 @@ main(int argc, char **argv)
         }
   }

-   /* small and colors are incomparible (will probably crash if both are used at
-    * the same time!)
-    */
-   if (small && colors[0] != 0)
-   {
-      fprintf(stderr, "makepng: --color --small: only one at a time!\n");
-      exit(1);
-   }
-
   /* Restrict the filters for more speed to those we know are used for the
    * generated images.
    */
-   if (filters == PNG_ALL_FILTERS && !small/*small provides defaults*/)
+   if (filters == PNG_ALL_FILTERS)
   {
      if ((color_type & PNG_COLOR_MASK_PALETTE) != 0 || bit_depth < 8)
         filters = PNG_FILTER_NONE;
@@ -1899,39 +1474,9 @@ main(int argc, char **argv)
         filters &= ~PNG_FILTER_NONE;
   }

-   /* Insert standard copyright and licence text. */
-   {
-      static png_const_charp copyright[] =
-      {
-         COPYRIGHT, /* ISO-Latin-1 */
-         NULL
-      };
-      static png_const_charp licensing[] =
-      {
-         IMAGE_LICENSING, /* UTF-8 */
-         NULL
-      };
-
-      chunk_insert *new_insert;
-
-      new_insert = add_tEXt("Copyright", copyright);
-      if (new_insert != NULL)
-      {
-         *insert_ptr = new_insert;
-         insert_ptr = &new_insert->next;
-      }
-
-      new_insert = add_iTXt("Licensing", "en", NULL, licensing);
-      if (new_insert != NULL)
-      {
-         *insert_ptr = new_insert;
-         insert_ptr = &new_insert->next;
-      }
-   }
-
   {
      int ret = write_png(&file_name, fp, color_type, bit_depth, gamma,
-         head_insert, filters, colors, small, tRNS);
+         head_insert, filters, colors);

      if (ret != 0 && file_name != NULL)
         remove(file_name);
--- a/contrib/libtests/pngimage.c
+++ b/contrib/libtests/pngimage.c
@@ -2,7 +2,7 @@
 *
 * Copyright (c) 2015 John Cunningham Bowler
 *
- * Last changed in libpng 1.6.20 [December 3, 2015]
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
@@ -36,8 +36,7 @@
 #  include <setjmp.h> /* because png.h did *not* include this */
 #endif

-#if defined(PNG_INFO_IMAGE_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_SUPPORTED)\
-    && (defined(PNG_READ_PNG_SUPPORTED) || PNG_LIBPNG_VER < 10700)
+#if defined(PNG_INFO_IMAGE_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_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
@@ -237,12 +236,10 @@ static struct transform_info
       */
 #endif
 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
-   T(SCALE_16,            NONE, X,   X,   16,  R),
+   T(SCALE_16,            NONE, X,   X,   16,  R)
      /* scales 16-bit components to 8-bits. */
 #endif

-   { NULL /*name*/, 0, 0, 0, 0, 0, 0, 0/*!tested*/ }
-
 #undef T
 };

@@ -297,7 +294,7 @@ transform_name(int t)

   t &= -t; /* first set bit */

-   for (i=0; i<TTABLE_SIZE; ++i) if (transform_info[i].name != NULL)
+   for (i=0; i<TTABLE_SIZE; ++i)
   {
      if ((transform_info[i].transform & t) != 0)
         return transform_info[i].name;
@@ -318,7 +315,7 @@ validate_T(void)
 {
   unsigned int i;

-   for (i=0; i<TTABLE_SIZE; ++i) if (transform_info[i].name != NULL)
+   for (i=0; i<TTABLE_SIZE; ++i)
   {
      if (transform_info[i].when & TRANSFORM_R)
         read_transforms |= transform_info[i].transform;
@@ -508,7 +505,6 @@ typedef enum
 #define SKIP_BUGS       0x100 /* Skip over known bugs */
 #define LOG_SKIPPED     0x200 /* Log skipped bugs */
 #define FIND_BAD_COMBOS 0x400 /* Attempt to deduce bad combos */
-#define LIST_COMBOS     0x800 /* List combos by name */

 /* Result masks apply to the result bits in the 'results' field below; these
 * bits are simple 1U<<error_level.  A pass requires either nothing worse than
@@ -694,35 +690,7 @@ display_log(struct display *dp, error_level level, const char *fmt, ...)
         int tr = dp->transforms;

         if (is_combo(tr))
-         {
-            if (dp->options & LIST_COMBOS)
-            {
-               int trx = tr;
-
-               fprintf(stderr, "(");
-               if (trx)
-               {
-                  int start = 0;
-
-                  while (trx)
-                  {
-                     int trz = trx & -trx;
-
-                     if (start) fprintf(stderr, "+");
-                     fprintf(stderr, "%s", transform_name(trz));
-                     start = 1;
-                     trx &= ~trz;
-                  }
-               }
-
-               else
-                  fprintf(stderr, "-");
-               fprintf(stderr, ")");
-            }
-
-            else
-               fprintf(stderr, "(0x%x)", tr);
-         }
+            fprintf(stderr, "(0x%x)", tr);

         else
            fprintf(stderr, "(%s)", transform_name(tr));
@@ -942,13 +910,13 @@ update_display(struct display *dp)
      int bd = dp->bit_depth;
      unsigned int i;

-      for (i=0; i<TTABLE_SIZE; ++i) if (transform_info[i].name != NULL)
+      for (i=0; i<TTABLE_SIZE; ++i)
      {
         int transform = transform_info[i].transform;

         if ((transform_info[i].valid_chunks == 0 ||
               (transform_info[i].valid_chunks & chunks) != 0) &&
-            (transform_info[i].color_mask_required & ct) ==
+            (transform_info[i].color_mask_required & ct) == 
               transform_info[i].color_mask_required &&
            (transform_info[i].color_mask_absent & ct) == 0 &&
            (transform_info[i].bit_depths & bd) != 0 &&
@@ -967,6 +935,9 @@ update_display(struct display *dp)

      dp->active_transforms = active;
      dp->ignored_transforms = inactive; /* excluding write-only transforms */
+
+      if (active == 0)
+         display_log(dp, INTERNAL_ERROR, "bad transform table");
   }
 }

@@ -1006,7 +977,7 @@ compare_read(struct display *dp, int applied_transforms)
   {
      unsigned long chunks =
         png_get_valid(dp->read_pp, dp->read_ip, 0xffffffff);
-
+      
      if (chunks != dp->chunks)
         display_log(dp, APP_FAIL, "PNG chunks changed from 0x%lx to 0x%lx",
            (unsigned long)dp->chunks, chunks);
@@ -1617,12 +1588,6 @@ main(const int argc, const char * const * const argv)
      else if (strcmp(name, "--nofind-bad-combos") == 0)
         d.options &= ~FIND_BAD_COMBOS;

-      else if (strcmp(name, "--list-combos") == 0)
-         d.options |= LIST_COMBOS;
-
-      else if (strcmp(name, "--nolist-combos") == 0)
-         d.options &= ~LIST_COMBOS;
-
      else if (name[0] == '-' && name[1] == '-')
      {
         fprintf(stderr, "pngimage: %s: unknown option\n", name);
@@ -1677,7 +1642,7 @@ main(const int argc, const char * const * const argv)
      return errors != 0;
   }
 }
-#else /* !INFO_IMAGE || !SEQUENTIAL_READ || !READ_PNG*/
+#else /* !PNG_INFO_IMAGE_SUPPORTED || !PNG_READ_SUPPORTED */
 int
 main(void)
 {
--- a/contrib/libtests/pngstest-errors.h
+++ b/contrib/libtests/pngstest-errors.h
@@ -1,165 +0,0 @@
-/* contrib/libtests/pngstest-errors.h
- *
- * BUILT USING: libpng version 1.6.19beta03 - September 25, 2015
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * THIS IS A MACHINE GENERATED FILE: do not edit it directly!
- * Instead run:
- *
- *    pngstest --accumulate
- *
- * on as many PNG files as possible; at least PNGSuite and
- * contrib/libtests/testpngs.
- */
-static png_uint_16 gpc_error[16/*in*/][16/*out*/][4/*a*/] =
-{
- { /* input: sRGB-gray */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 372, 0 }, { 0, 0, 372, 0 }, { 0, 0, 372, 0 }, { 0, 0, 372, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: sRGB-gray+alpha */
-  { 0, 19, 0, 0 }, { 0, 0, 0, 0 }, { 0, 20, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: sRGB-rgb */
-  { 0, 0, 19, 0 }, { 0, 0, 19, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 893, 0 }, { 0, 0, 893, 0 }, { 0, 0, 811, 0 }, { 0, 0, 811, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: sRGB-rgb+alpha */
-  { 0, 16, 17, 0 }, { 0, 17, 17, 0 }, { 0, 19, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 850, 875, 0 }, { 0, 850, 875, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: linear-gray */
-  { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: linear-gray+alpha */
-  { 0, 74, 9, 0 }, { 0, 20, 9, 0 }, { 0, 74, 9, 0 }, { 0, 20, 9, 0 },
-  { 0, 0, 0, 0 }, { 0, 1, 0, 0 }, { 0, 0, 0, 0 }, { 0, 1, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: linear-rgb */
-  { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 },
-  { 0, 0, 4, 0 }, { 0, 0, 4, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: linear-rgb+alpha */
-  { 0, 126, 143, 0 }, { 0, 11, 7, 0 }, { 0, 74, 9, 0 }, { 0, 17, 9, 0 },
-  { 0, 4, 4, 0 }, { 0, 5, 4, 0 }, { 0, 0, 0, 0 }, { 0, 1, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-sRGB-gray */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-sRGB-gray+alpha */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-sRGB-rgb */
-  { 0, 0, 13, 0 }, { 0, 0, 13, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 },
-  { 0, 0, 673, 0 }, { 0, 0, 673, 0 }, { 0, 0, 674, 0 }, { 0, 0, 674, 0 },
-  { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 460, 0 }, { 0, 0, 460, 0 }, { 0, 0, 263, 0 }, { 0, 0, 263, 0 }
- }, { /* input: color-mapped-sRGB-rgb+alpha */
-  { 0, 6, 8, 0 }, { 0, 7, 8, 0 }, { 0, 75, 9, 0 }, { 0, 9, 9, 0 },
-  { 0, 585, 427, 0 }, { 0, 585, 427, 0 }, { 0, 717, 514, 0 }, { 0, 717, 514, 0 },
-  { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 13323, 460, 0 }, { 0, 427, 460, 0 }, { 0, 16480, 263, 0 }, { 0, 243, 263, 0 }
- }, { /* input: color-mapped-linear-gray */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 282, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-linear-gray+alpha */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 253, 282, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-linear-rgb */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 265, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-linear-rgb+alpha */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 243, 265, 0 }
- }
-};
-static png_uint_16 gpc_error_via_linear[16][4/*out*/][4] =
-{
- { /* input: sRGB-gray */
-  { 0, 0, 7, 0 }, { 0, 0, 7, 0 }, { 0, 0, 7, 0 }, { 0, 0, 7, 0 }
- }, { /* input: sRGB-gray+alpha */
-  { 0, 15, 15, 0 }, { 0, 186, 15, 0 }, { 0, 15, 15, 0 }, { 0, 186, 15, 0 }
- }, { /* input: sRGB-rgb */
-  { 0, 0, 20, 0 }, { 0, 0, 20, 0 }, { 0, 0, 15, 0 }, { 0, 0, 15, 0 }
- }, { /* input: sRGB-rgb+alpha */
-  { 0, 16, 17, 0 }, { 0, 187, 17, 0 }, { 0, 15, 15, 0 }, { 0, 186, 15, 0 }
- }, { /* input: linear-gray */
-  { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }
- }, { /* input: linear-gray+alpha */
-  { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 1, 0 }
- }, { /* input: linear-rgb */
-  { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }
- }, { /* input: linear-rgb+alpha */
-  { 0, 1, 1, 0 }, { 0, 9, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 1, 0 }
- }, { /* input: color-mapped-sRGB-gray */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-sRGB-gray+alpha */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-sRGB-rgb */
-  { 0, 0, 13, 0 }, { 0, 0, 13, 0 }, { 0, 0, 14, 0 }, { 0, 0, 14, 0 }
- }, { /* input: color-mapped-sRGB-rgb+alpha */
-  { 0, 4, 8, 0 }, { 0, 9, 8, 0 }, { 0, 9, 5, 0 }, { 0, 32, 5, 0 }
- }, { /* input: color-mapped-linear-gray */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-linear-gray+alpha */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-linear-rgb */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }, { /* input: color-mapped-linear-rgb+alpha */
-  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
- }
-};
-static png_uint_16 gpc_error_to_colormap[8/*i*/][8/*o*/][4] =
-{
- { /* input: sRGB-gray */
-  { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 },
-  { 0, 0, 560, 0 }, { 0, 0, 560, 0 }, { 0, 0, 560, 0 }, { 0, 0, 560, 0 }
- }, { /* input: sRGB-gray+alpha */
-  { 0, 19, 9, 0 }, { 0, 255, 9, 25 }, { 0, 88, 9, 0 }, { 0, 255, 9, 25 },
-  { 0, 1012, 928, 0 }, { 0, 16026, 928, 6425 }, { 0, 1012, 928, 0 }, { 0, 16026, 928, 6425 }
- }, { /* input: sRGB-rgb */
-  { 0, 0, 19, 0 }, { 0, 0, 19, 0 }, { 0, 0, 25, 0 }, { 0, 0, 25, 0 },
-  { 0, 0, 962, 0 }, { 0, 0, 962, 0 }, { 0, 0, 13677, 0 }, { 0, 0, 13677, 0 }
- }, { /* input: sRGB-rgb+alpha */
-  { 0, 63, 77, 0 }, { 0, 255, 19, 25 }, { 0, 225, 25, 0 }, { 0, 255, 25, 67 },
-  { 0, 17534, 18491, 0 }, { 0, 15736, 2824, 6425 }, { 0, 14019, 13677, 0 }, { 0, 50115, 13677, 17219 }
- }, { /* input: linear-gray */
-  { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 73, 0 },
-  { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }
- }, { /* input: linear-gray+alpha */
-  { 0, 74, 74, 0 }, { 0, 255, 74, 25 }, { 0, 99, 74, 0 }, { 0, 255, 74, 25 },
-  { 0, 18919, 18907, 0 }, { 0, 24549, 18907, 6553 }, { 0, 18919, 18907, 0 }, { 0, 24549, 18907, 6553 }
- }, { /* input: linear-rgb */
-  { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 98, 0 }, { 0, 0, 98, 0 },
-  { 0, 0, 18664, 0 }, { 0, 0, 18664, 0 }, { 0, 0, 24998, 0 }, { 0, 0, 24998, 0 }
- }, { /* input: linear-rgb+alpha */
-  { 0, 181, 196, 0 }, { 0, 255, 61, 25 }, { 206, 187, 98, 0 }, { 0, 255, 98, 67 },
-  { 0, 18141, 18137, 0 }, { 0, 17494, 17504, 6553 }, { 0, 24979, 24992, 0 }, { 0, 49172, 24992, 17347 }
- }
-};
-/* END MACHINE GENERATED */
--- a/contrib/libtests/pngstest.c
+++ b/contrib/libtests/pngstest.c
@@ -3,7 +3,7 @@
 *
 * Copyright (c) 2013-2015 John Cunningham Bowler
 *
- * Last changed in libpng 1.6.19 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
@@ -1984,7 +1984,156 @@ static void (* const gpc_fn_colormapped[8/*in*/][8/*out*/])
 * gpc_error_to_colormap.
 */
 #if PNG_FORMAT_FLAG_COLORMAP == 8 /* extra check also required */
-#  include "pngstest-errors.h" /* machine generated */
+/* START MACHINE GENERATED */
+static png_uint_16 gpc_error[16/*in*/][16/*out*/][4/*a*/] =
+{
+ { /* input: sRGB-gray */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 372, 0 }, { 0, 0, 372, 0 }, { 0, 0, 372, 0 }, { 0, 0, 372, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: sRGB-gray+alpha */
+  { 0, 18, 0, 0 }, { 0, 0, 0, 0 }, { 0, 20, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: sRGB-rgb */
+  { 0, 0, 19, 0 }, { 0, 0, 19, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 893, 0 }, { 0, 0, 893, 0 }, { 0, 0, 811, 0 }, { 0, 0, 811, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: sRGB-rgb+alpha */
+  { 0, 4, 13, 0 }, { 0, 14, 13, 0 }, { 0, 19, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 832, 764, 0 }, { 0, 832, 764, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: linear-gray */
+  { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: linear-gray+alpha */
+  { 0, 74, 9, 0 }, { 0, 20, 9, 0 }, { 0, 74, 9, 0 }, { 0, 20, 9, 0 },
+  { 0, 0, 0, 0 }, { 0, 1, 0, 0 }, { 0, 0, 0, 0 }, { 0, 1, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: linear-rgb */
+  { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 },
+  { 0, 0, 4, 0 }, { 0, 0, 4, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: linear-rgb+alpha */
+  { 0, 126, 143, 0 }, { 0, 9, 7, 0 }, { 0, 74, 9, 0 }, { 0, 16, 9, 0 },
+  { 0, 4, 4, 0 }, { 0, 5, 4, 0 }, { 0, 0, 0, 0 }, { 0, 1, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-sRGB-gray */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-sRGB-gray+alpha */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-sRGB-rgb */
+  { 0, 0, 13, 0 }, { 0, 0, 13, 0 }, { 0, 0, 8, 0 }, { 0, 0, 8, 0 },
+  { 0, 0, 673, 0 }, { 0, 0, 673, 0 }, { 0, 0, 674, 0 }, { 0, 0, 674, 0 },
+  { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 460, 0 }, { 0, 0, 460, 0 }, { 0, 0, 263, 0 }, { 0, 0, 263, 0 }
+ }, { /* input: color-mapped-sRGB-rgb+alpha */
+  { 0, 6, 8, 0 }, { 0, 7, 8, 0 }, { 0, 75, 8, 0 }, { 0, 9, 8, 0 },
+  { 0, 585, 427, 0 }, { 0, 585, 427, 0 }, { 0, 717, 409, 0 }, { 0, 717, 409, 0 },
+  { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 13323, 460, 0 }, { 0, 334, 460, 0 }, { 0, 16480, 263, 0 }, { 0, 243, 263, 0 }
+ }, { /* input: color-mapped-linear-gray */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 282, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-linear-gray+alpha */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 253, 282, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-linear-rgb */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 265, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-linear-rgb+alpha */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 243, 265, 0 }
+ }
+};
+static png_uint_16 gpc_error_via_linear[16][4/*out*/][4] =
+{
+ { /* input: sRGB-gray */
+  { 0, 0, 7, 0 }, { 0, 0, 7, 0 }, { 0, 0, 7, 0 }, { 0, 0, 7, 0 }
+ }, { /* input: sRGB-gray+alpha */
+  { 0, 15, 15, 0 }, { 0, 186, 15, 0 }, { 0, 15, 15, 0 }, { 0, 186, 15, 0 }
+ }, { /* input: sRGB-rgb */
+  { 0, 0, 19, 0 }, { 0, 0, 19, 0 }, { 0, 0, 15, 0 }, { 0, 0, 15, 0 }
+ }, { /* input: sRGB-rgb+alpha */
+  { 0, 12, 14, 0 }, { 0, 180, 14, 0 }, { 0, 14, 15, 0 }, { 0, 186, 15, 0 }
+ }, { /* input: linear-gray */
+  { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }
+ }, { /* input: linear-gray+alpha */
+  { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 1, 0 }
+ }, { /* input: linear-rgb */
+  { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }
+ }, { /* input: linear-rgb+alpha */
+  { 0, 1, 1, 0 }, { 0, 8, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 1, 0 }
+ }, { /* input: color-mapped-sRGB-gray */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-sRGB-gray+alpha */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-sRGB-rgb */
+  { 0, 0, 13, 0 }, { 0, 0, 13, 0 }, { 0, 0, 14, 0 }, { 0, 0, 14, 0 }
+ }, { /* input: color-mapped-sRGB-rgb+alpha */
+  { 0, 4, 8, 0 }, { 0, 9, 8, 0 }, { 0, 8, 3, 0 }, { 0, 32, 3, 0 }
+ }, { /* input: color-mapped-linear-gray */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-linear-gray+alpha */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-linear-rgb */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }, { /* input: color-mapped-linear-rgb+alpha */
+  { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
+ }
+};
+static png_uint_16 gpc_error_to_colormap[8/*i*/][8/*o*/][4] =
+{
+ { /* input: sRGB-gray */
+  { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 },
+  { 0, 0, 560, 0 }, { 0, 0, 560, 0 }, { 0, 0, 560, 0 }, { 0, 0, 560, 0 }
+ }, { /* input: sRGB-gray+alpha */
+  { 0, 19, 2, 0 }, { 0, 255, 2, 25 }, { 0, 88, 2, 0 }, { 0, 255, 2, 25 },
+  { 0, 1012, 745, 0 }, { 0, 16026, 745, 6425 }, { 0, 1012, 745, 0 }, { 0, 16026, 745, 6425 }
+ }, { /* input: sRGB-rgb */
+  { 0, 0, 19, 0 }, { 0, 0, 19, 0 }, { 0, 0, 25, 0 }, { 0, 0, 25, 0 },
+  { 0, 0, 937, 0 }, { 0, 0, 937, 0 }, { 0, 0, 13677, 0 }, { 0, 0, 13677, 0 }
+ }, { /* input: sRGB-rgb+alpha */
+  { 0, 63, 77, 0 }, { 0, 255, 19, 25 }, { 0, 220, 25, 0 }, { 0, 255, 25, 67 },
+  { 0, 17534, 18491, 0 }, { 0, 15614, 2824, 6425 }, { 0, 14019, 13677, 0 }, { 0, 48573, 13677, 17219 }
+ }, { /* input: linear-gray */
+  { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 73, 0 },
+  { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }
+ }, { /* input: linear-gray+alpha */
+  { 0, 74, 74, 0 }, { 0, 255, 74, 25 }, { 0, 97, 74, 0 }, { 0, 255, 74, 25 },
+  { 0, 18919, 18907, 0 }, { 0, 24549, 18907, 6552 }, { 0, 18919, 18907, 0 }, { 0, 24549, 18907, 6552 }
+ }, { /* input: linear-rgb */
+  { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 98, 0 }, { 0, 0, 98, 0 },
+  { 0, 0, 18664, 0 }, { 0, 0, 18664, 0 }, { 0, 0, 24998, 0 }, { 0, 0, 24998, 0 }
+ }, { /* input: linear-rgb+alpha */
+  { 0, 181, 196, 0 }, { 0, 255, 61, 25 }, { 206, 187, 98, 0 }, { 0, 255, 98, 67 },
+  { 0, 18141, 18137, 0 }, { 0, 17494, 17504, 6553 }, { 0, 24979, 24992, 0 }, { 0, 46509, 24992, 17347 }
+ }
+};
+/* END MACHINE GENERATED */
 #endif /* COLORMAP flag check */
 #endif /* flag checks */

@@ -2005,7 +2154,7 @@ typedef struct
   int          in_opaque;   /* Value of input alpha that is opaque */
   int          is_palette;  /* Sample values come from the palette */
   int          accumulate;  /* Accumlate component errors (don't log) */
-   int          output_8bit; /* Output is 8-bit (else 16-bit) */
+   int          output_8bit; /* Output is 8 bit (else 16 bit) */

   void (*in_gp)(Pixel*, png_const_voidp);
   void (*out_gp)(Pixel*, png_const_voidp);
@@ -3130,7 +3279,7 @@ write_one_file(Image *output, Image *image, int convert_to_8bit)
        (void) unlink(tmpfile);
      }
 #endif
-
+      
      if (f != NULL)
      {
         if (png_image_write_to_stdio(&image->image, f, convert_to_8bit,
@@ -3573,23 +3722,6 @@ main(int argc, char **argv)
   {
      unsigned int in;

-      printf("/* contrib/libtests/pngstest-errors.h\n");
-      printf(" *\n");
-      printf(" * BUILT USING:" PNG_HEADER_VERSION_STRING);
-      printf(" *\n");
-      printf(" * This code is released under the libpng license.\n");
-      printf(" * For conditions of distribution and use, see the disclaimer\n");
-      printf(" * and license in png.h\n");
-      printf(" *\n");
-      printf(" * THIS IS A MACHINE GENERATED FILE: do not edit it directly!\n");
-      printf(" * Instead run:\n");
-      printf(" *\n");
-      printf(" *    pngstest --accumulate\n");
-      printf(" *\n");
-      printf(" * on as many PNG files as possible; at least PNGSuite and\n");
-      printf(" * contrib/libtests/testpngs.\n");
-      printf(" */\n");
-
      printf("static png_uint_16 gpc_error[16/*in*/][16/*out*/][4/*a*/] =\n");
      printf("{\n");
      for (in=0; in<16; ++in)
@@ -3679,7 +3811,6 @@ main(int argc, char **argv)
            putchar('\n');
      }
      printf("};\n");
-      printf("/* END MACHINE GENERATED */\n");
   }

   if (retval == 0 && touch != NULL)
--- a/contrib/libtests/pngunknown.c
+++ b/contrib/libtests/pngunknown.c
@@ -363,7 +363,7 @@ ancillary(const char *name)
   return PNG_CHUNK_ANCILLARY(PNG_U32(name[0], name[1], name[2], name[3]));
 }

-#ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 static int
 ancillaryb(const png_byte *name)
 {
@@ -554,7 +554,7 @@ read_callback(png_structp pp, png_unknown_chunkp pc)
   /* However if there is no support to store unknown chunks don't ask libpng to
    * do it; there will be an png_error.
    */
-#  ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+#  ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
      return discard;
 #  else
      return 1; /*handled; discard*/
@@ -562,7 +562,7 @@ read_callback(png_structp pp, png_unknown_chunkp pc)
 }
 #endif /* READ_USER_CHUNKS_SUPPORTED */

-#ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 static png_uint_32
 get_unknown(display *d, png_infop info_ptr, int after_IDAT)
 {
@@ -722,17 +722,11 @@ check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
                   * in this case, so we just check the arguments!  This could
                   * be improved in the future by using the read callback.
                   */
-#                 if PNG_LIBPNG_VER >= 10700 &&\
-                     !defined(PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED)
-                     if (option < PNG_HANDLE_CHUNK_IF_SAFE)
-#                 endif /* 1.7+ SAVE_UNKNOWN_CHUNKS */
-                  {
-                     png_byte name[5];
+                  png_byte name[5];

-                     memcpy(name, chunk_info[chunk].name, 5);
-                     png_set_keep_unknown_chunks(d->png_ptr, option, name, 1);
-                     chunk_info[chunk].keep = option;
-                  }
+                  memcpy(name, chunk_info[chunk].name, 5);
+                  png_set_keep_unknown_chunks(d->png_ptr, option, name, 1);
+                  chunk_info[chunk].keep = option;
                  continue;
               }

@@ -741,12 +735,7 @@ check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
            case 7: /* default */
               if (memcmp(argv[i], "default", 7) == 0)
               {
-#                 if PNG_LIBPNG_VER >= 10700 &&\
-                     !defined(PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED)
-                     if (option < PNG_HANDLE_CHUNK_IF_SAFE)
-#                 endif /* 1.7+ SAVE_UNKNOWN_CHUNKS */
-                     png_set_keep_unknown_chunks(d->png_ptr, option, NULL, 0);
-
+                  png_set_keep_unknown_chunks(d->png_ptr, option, NULL, 0);
                  d->keep = option;
                  continue;
               }
@@ -756,12 +745,7 @@ check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
            case 3: /* all */
               if (memcmp(argv[i], "all", 3) == 0)
               {
-#                 if PNG_LIBPNG_VER >= 10700 &&\
-                     !defined(PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED)
-                     if (option < PNG_HANDLE_CHUNK_IF_SAFE)
-#                 endif /* 1.7+ SAVE_UNKNOWN_CHUNKS */
-                     png_set_keep_unknown_chunks(d->png_ptr, option, NULL, -1);
-
+                  png_set_keep_unknown_chunks(d->png_ptr, option, NULL, -1);
                  d->keep = option;

                  for (chunk = 0; chunk < NINFO; ++chunk)
@@ -1258,4 +1242,4 @@ main(void)
   /* So the test is skipped: */
   return 77;
 }
-#endif /* SET_UNKNOWN_CHUNKS && READ*/
+#endif /* SET_UNKNOWN_CHUNKS && READ */
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
--- a/contrib/libtests/readpng.c
+++ b/contrib/libtests/readpng.c
@@ -62,7 +62,6 @@ read_png(FILE *fp)
   {
      png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);

-      /* Failure to initialize these is harmless */
      row = malloc(rowbytes);
      display = malloc(rowbytes);

@@ -71,12 +70,7 @@ read_png(FILE *fp)

      {
         png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
-#        ifdef PNG_READ_INTERLACING_SUPPORTED
-            int passes = png_set_interlace_handling(png_ptr);
-#        else /* !READ_INTERLACING */
-            int passes = png_get_interlace_type(png_ptr, info_ptr) ==
-               PNG_INTERLACE_ADAM7 ? PNG_INTERLACE_ADAM7_PASSES : 1;
-#        endif /* !READ_INTERLACING */
+         int passes = png_set_interlace_handling(png_ptr);
         int pass;

         png_start_read_image(png_ptr);
@@ -85,11 +79,6 @@ read_png(FILE *fp)
         {
            png_uint_32 y = height;

-#           ifndef PNG_READ_INTERLACING_SUPPORTED
-               if (passes == PNG_INTERLACE_ADAM7_PASSES)
-                  y = PNG_PASS_ROWS(y, pass);
-#           endif /* READ_INTERLACING */
-
            /* NOTE: this trashes the row each time; interlace handling won't
             * work, but this avoids memory thrashing for speed testing.
             */
--- a/contrib/libtests/tarith.c
+++ b/contrib/libtests/tarith.c
@@ -634,7 +634,7 @@ int validation_muldiv(int count, int argc, char **argv)
   {
      png_fixed_point result;
      /* NOTE: your mileage may vary, a type is required below that can
-       * hold 64 bits or more, if floating point is used a 64-bit or
+       * hold 64 bits or more, if floating point is used a 64 bit or
       * better mantissa is required.
       */
      long long int fp, fpround;
@@ -721,7 +721,7 @@ int validation_muldiv(int count, int argc, char **argv)
   }
   while (--count > 0);

-   printf("%d tests including %d overflows, %d passed, %d failed (%d 64-bit "
+   printf("%d tests including %d overflows, %d passed, %d failed (%d 64 bit "
      "errors)\n", tested, overflow, passed, error, error64);
   return 0;
 }
@@ -799,13 +799,13 @@ int validation_gamma(int argc, char **argv)
         if (i == 0 && png_log8bit(i) != 0xffffffff ||
             i != 0 && png_log8bit(i) != floor(correct+.5))
         {
-            fprintf(stderr, "8-bit log error: %d: got %u, expected %f\n",
+            fprintf(stderr, "8 bit log error: %d: got %u, expected %f\n",
               i, png_log8bit(i), correct);
         }
      }

      if (!silent)
-         printf("maximum 8-bit log error = %f\n", maxerr);
+         printf("maximum 8 bit log error = %f\n", maxerr);

      maxerr = 0;
      for (i=0; i<65536; ++i)
@@ -821,14 +821,14 @@ int validation_gamma(int argc, char **argv)
         {
            if (error > .68) /* By experiment error is less than .68 */
            {
-               fprintf(stderr, "16-bit log error: %d: got %u, expected %f"
+               fprintf(stderr, "16 bit log error: %d: got %u, expected %f"
                  " error: %f\n", i, png_log16bit(i), correct, error);
            }
         }
      }

      if (!silent)
-         printf("maximum 16-bit log error = %f\n", maxerr);
+         printf("maximum 16 bit log error = %f\n", maxerr);

      /* Now exponentiations. */
      maxerr = 0;
@@ -841,13 +841,13 @@ int validation_gamma(int argc, char **argv)
            maxerr = fabs(error);
         if (fabs(error) > 1883) /* By experiment. */
         {
-            fprintf(stderr, "32-bit exp error: %d: got %u, expected %f"
+            fprintf(stderr, "32 bit exp error: %d: got %u, expected %f"
                  " error: %f\n", i, png_exp(i), correct, error);
         }
      }

      if (!silent)
-         printf("maximum 32-bit exp error = %f\n", maxerr);
+         printf("maximum 32 bit exp error = %f\n", maxerr);

      maxerr = 0;
      for (i=0; i<=0xfffff; ++i)
@@ -859,13 +859,13 @@ int validation_gamma(int argc, char **argv)
            maxerr = fabs(error);
         if (fabs(error) > .50002) /* By experiment */
         {
-            fprintf(stderr, "8-bit exp error: %d: got %u, expected %f"
+            fprintf(stderr, "8 bit exp error: %d: got %u, expected %f"
                  " error: %f\n", i, png_exp8bit(i), correct, error);
         }
      }

      if (!silent)
-         printf("maximum 8-bit exp error = %f\n", maxerr);
+         printf("maximum 8 bit exp error = %f\n", maxerr);

      maxerr = 0;
      for (i=0; i<=0xfffff; ++i)
@@ -877,13 +877,13 @@ int validation_gamma(int argc, char **argv)
            maxerr = fabs(error);
         if (fabs(error) > .524) /* By experiment */
         {
-            fprintf(stderr, "16-bit exp error: %d: got %u, expected %f"
+            fprintf(stderr, "16 bit exp error: %d: got %u, expected %f"
                  " error: %f\n", i, png_exp16bit(i), correct, error);
         }
      }

      if (!silent)
-         printf("maximum 16-bit exp error = %f\n", maxerr);
+         printf("maximum 16 bit exp error = %f\n", maxerr);
   } /* !onlygamma */

   /* Test the overall gamma correction. */
@@ -913,7 +913,7 @@ int validation_gamma(int argc, char **argv)
      }

      if (!silent)
-         printf("gamma %f: maximum 8-bit error %f\n", g, maxerr);
+         printf("gamma %f: maximum 8 bit error %f\n", g, maxerr);

      maxerr = 0;
      for (j=0; j<65536; ++j)
@@ -932,7 +932,7 @@ int validation_gamma(int argc, char **argv)
      }

      if (!silent)
-         printf("gamma %f: maximum 16-bit error %f\n", g, maxerr);
+         printf("gamma %f: maximum 16 bit error %f\n", g, maxerr);
   }

   return 0;
--- a/contrib/pngminus/png2pnm.c
+++ b/contrib/pngminus/png2pnm.c
@@ -266,7 +266,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
    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 */
--- a/contrib/pngminus/pnm2png.c
+++ b/contrib/pngminus/pnm2png.c
@@ -3,7 +3,6 @@
 *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
 *
 *  version 1.0 - 1999.10.15 - First version.
- *  version 1.1 - 2015.07.29 - Fixed leaks (Glenn Randers-Pehrson)
 *
 *  Permission to use, copy, modify, and distribute this software and
 *  its documentation for any purpose and without fee is hereby granted,
@@ -201,17 +200,17 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
  char          width_token[16];
  char          height_token[16];
  char          maxval_token[16];
-  volatile int    color_type=1;
+  volatile int           color_type;
  unsigned long   ul_width=0, ul_alpha_width=0;
  unsigned long   ul_height=0, ul_alpha_height=0;
  unsigned long   ul_maxval=0;
-  volatile png_uint_32   width=0, height=0;
-  volatile png_uint_32   alpha_width=0, alpha_height=0;
+  volatile png_uint_32   width, height;
+  volatile png_uint_32   alpha_width, alpha_height;
  png_uint_32   maxval;
  volatile int           bit_depth = 0;
-  int           channels=0;
+  int           channels;
  int           alpha_depth = 0;
-  int           alpha_present=0;
+  int           alpha_present;
  int           row, col;
  BOOL          raw, alpha_raw = FALSE;
 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
@@ -357,10 +356,8 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
    channels = 3;
  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
    channels = 4;
-#if 0
  else
-    channels = 0; /* cannot happen */
-#endif
+    channels = 0; /* should not happen */

  alpha_present = (channels - 1) % 2;

@@ -432,16 +429,12 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
      NULL);
  if (!png_ptr)
  {
-    free (png_pixels);
-    png_pixels = NULL;
    return FALSE;
  }
  info_ptr = png_create_info_struct (png_ptr);
  if (!info_ptr)
  {
    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
-    free (png_pixels);
-    png_pixels = NULL;
    return FALSE;
  }

@@ -456,9 +449,7 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
  /* setjmp() must be called in every function that calls a PNG-reading libpng function */
  if (setjmp (png_jmpbuf(png_ptr)))
  {
-    png_destroy_write_struct (&png_ptr, &info_ptr);
-    free (png_pixels);
-    png_pixels = NULL;
+    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
    return FALSE;
  }

@@ -479,9 +470,7 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
    if ((row_pointers = (png_byte **)
        malloc (height * sizeof (png_bytep))) == NULL)
    {
-      png_destroy_write_struct (&png_ptr, &info_ptr);
-      free (png_pixels);
-      png_pixels = NULL;
+      png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
      return FALSE;
    }
  }
@@ -497,7 +486,7 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
  png_write_end (png_ptr, info_ptr);

  /* clean up after the write, and free any memory allocated */
-  png_destroy_write_struct (&png_ptr, &info_ptr);
+  png_destroy_write_struct (&png_ptr, (png_infopp) NULL);

  if (row_pointers != (unsigned char**) NULL)
    free (row_pointers);
--- a/contrib/pngsuite/README
+++ b/contrib/pngsuite/README
@@ -1,8 +1,8 @@

 pngsuite
 --------
-Copyright (c) Willem van Schaik, 1999, 2011, 2012
-Two images (ftbbn0g01.png and ftbbn0g02.png) are by Glenn Randers-Pehrson, 2012
+(c) Willem van Schaik, 1999, 2011, 2012
+Two images are by Glenn Randers-Pehrson, 2012

 Permission to use, copy, modify, and distribute these images for any
 purpose and without fee is hereby granted.
--- a/contrib/testpngs/gray-1-1.8-tRNS.png
+++ b/contrib/testpngs/gray-1-1.8-tRNS.png
--- a/contrib/testpngs/gray-1-1.8.png
+++ b/contrib/testpngs/gray-1-1.8.png
--- a/contrib/testpngs/gray-1-linear-tRNS.png
+++ b/contrib/testpngs/gray-1-linear-tRNS.png
--- a/contrib/testpngs/gray-1-linear.png
+++ b/contrib/testpngs/gray-1-linear.png
--- a/contrib/testpngs/gray-1-sRGB-tRNS.png
+++ b/contrib/testpngs/gray-1-sRGB-tRNS.png
--- a/contrib/testpngs/gray-1-sRGB.png
+++ b/contrib/testpngs/gray-1-sRGB.png
--- a/contrib/testpngs/gray-1-tRNS.png
+++ b/contrib/testpngs/gray-1-tRNS.png
--- a/contrib/testpngs/gray-1.png
+++ b/contrib/testpngs/gray-1.png
--- a/contrib/testpngs/gray-16-1.8-tRNS.png
+++ b/contrib/testpngs/gray-16-1.8-tRNS.png
--- a/contrib/testpngs/gray-16-1.8.png
+++ b/contrib/testpngs/gray-16-1.8.png
--- a/contrib/testpngs/gray-16-linear-tRNS.png
+++ b/contrib/testpngs/gray-16-linear-tRNS.png
--- a/contrib/testpngs/gray-16-linear.png
+++ b/contrib/testpngs/gray-16-linear.png
--- a/contrib/testpngs/gray-16-sRGB-tRNS.png
+++ b/contrib/testpngs/gray-16-sRGB-tRNS.png
--- a/contrib/testpngs/gray-16-sRGB.png
+++ b/contrib/testpngs/gray-16-sRGB.png
--- a/contrib/testpngs/gray-16-tRNS.png
+++ b/contrib/testpngs/gray-16-tRNS.png
--- a/contrib/testpngs/gray-16.png
+++ b/contrib/testpngs/gray-16.png
--- a/contrib/testpngs/gray-2-1.8-tRNS.png
+++ b/contrib/testpngs/gray-2-1.8-tRNS.png
--- a/contrib/testpngs/gray-2-1.8.png
+++ b/contrib/testpngs/gray-2-1.8.png
--- a/contrib/testpngs/gray-2-linear-tRNS.png
+++ b/contrib/testpngs/gray-2-linear-tRNS.png
--- a/contrib/testpngs/gray-2-linear.png
+++ b/contrib/testpngs/gray-2-linear.png
--- a/contrib/testpngs/gray-2-sRGB-tRNS.png
+++ b/contrib/testpngs/gray-2-sRGB-tRNS.png
--- a/contrib/testpngs/gray-2-sRGB.png
+++ b/contrib/testpngs/gray-2-sRGB.png
--- a/contrib/testpngs/gray-2-tRNS.png
+++ b/contrib/testpngs/gray-2-tRNS.png
--- a/contrib/testpngs/gray-2.png
+++ b/contrib/testpngs/gray-2.png
--- a/contrib/testpngs/gray-4-1.8-tRNS.png
+++ b/contrib/testpngs/gray-4-1.8-tRNS.png
--- a/contrib/testpngs/gray-4-1.8.png
+++ b/contrib/testpngs/gray-4-1.8.png
--- a/contrib/testpngs/gray-4-linear-tRNS.png
+++ b/contrib/testpngs/gray-4-linear-tRNS.png
--- a/contrib/testpngs/gray-4-linear.png
+++ b/contrib/testpngs/gray-4-linear.png
--- a/contrib/testpngs/gray-4-sRGB-tRNS.png
+++ b/contrib/testpngs/gray-4-sRGB-tRNS.png
--- a/contrib/testpngs/gray-4-sRGB.png
+++ b/contrib/testpngs/gray-4-sRGB.png
--- a/contrib/testpngs/gray-4-tRNS.png
+++ b/contrib/testpngs/gray-4-tRNS.png
--- a/contrib/testpngs/gray-4.png
+++ b/contrib/testpngs/gray-4.png
--- a/contrib/testpngs/gray-8-1.8-tRNS.png
+++ b/contrib/testpngs/gray-8-1.8-tRNS.png
--- a/contrib/testpngs/gray-8-1.8.png
+++ b/contrib/testpngs/gray-8-1.8.png
--- a/contrib/testpngs/gray-8-linear-tRNS.png
+++ b/contrib/testpngs/gray-8-linear-tRNS.png
--- a/contrib/testpngs/gray-8-linear.png
+++ b/contrib/testpngs/gray-8-linear.png
--- a/contrib/testpngs/gray-8-sRGB-tRNS.png
+++ b/contrib/testpngs/gray-8-sRGB-tRNS.png
--- a/contrib/testpngs/gray-8-sRGB.png
+++ b/contrib/testpngs/gray-8-sRGB.png
--- a/contrib/testpngs/gray-8-tRNS.png
+++ b/contrib/testpngs/gray-8-tRNS.png
--- a/contrib/testpngs/gray-8.png
+++ b/contrib/testpngs/gray-8.png
--- a/contrib/testpngs/gray-alpha-16-1.8.png
+++ b/contrib/testpngs/gray-alpha-16-1.8.png
--- a/contrib/testpngs/gray-alpha-16-linear.png
+++ b/contrib/testpngs/gray-alpha-16-linear.png
--- a/contrib/testpngs/gray-alpha-16-sRGB.png
+++ b/contrib/testpngs/gray-alpha-16-sRGB.png
--- a/contrib/testpngs/gray-alpha-16.png
+++ b/contrib/testpngs/gray-alpha-16.png
--- a/contrib/testpngs/gray-alpha-8-1.8.png
+++ b/contrib/testpngs/gray-alpha-8-1.8.png
--- a/contrib/testpngs/gray-alpha-8-linear.png
+++ b/contrib/testpngs/gray-alpha-8-linear.png
--- a/contrib/testpngs/gray-alpha-8-sRGB.png
+++ b/contrib/testpngs/gray-alpha-8-sRGB.png
--- a/contrib/testpngs/gray-alpha-8.png
+++ b/contrib/testpngs/gray-alpha-8.png
--- a/contrib/testpngs/makepngs.sh
+++ b/contrib/testpngs/makepngs.sh
@@ -1,94 +0,0 @@
-#!/bin/sh
-#
-# Make a set of test PNG files, MAKEPNG is the name of the makepng executable
-# built from contrib/libtests/makepng.c
-
-# Copyright (c) 2015 John Cunningham Bowler
-
-# Last changed in libpng 1.7.0 [(PENDING RELEASE)]
-
-# This code is released under the libpng license.
-# For conditions of distribution and use, see the disclaimer
-# and license in png.h
-
-# The arguments say whether to build all the files or whether just to build the
-# ones that extend the code-coverage of libpng from the existing test files in
-# contrib/pngsuite.
-test -n "$MAKEPNG" || MAKEPNG=./makepng
-opts=
-
-mp(){
-   ${MAKEPNG} $opts $1 "$3" "$4" "$3-$4$2.png"
-}
-
-mpg(){
-   if test "$1" = "none"
-   then
-      mp "" "" "$2" "$3"
-   else
-      mp "--$1" "-$1" "$2" "$3"
-   fi
-}
-
-mptrans(){
-   if test "$1" = "none"
-   then
-      mp "--tRNS" "-tRNS" "$2" "$3"
-   else
-      mp "--tRNS --$1" "-$1-tRNS" "$2" "$3"
-   fi
-}
-
-case "$1" in
-   --small)
-      opts="--small";;&
-
-   --all|--small)
-      for g in none sRGB linear 1.8
-      do
-         for c in gray palette
-         do
-            for b in 1 2 4
-            do
-               mpg "$g" "$c" "$b"
-               mptrans "$g" "$c" "$b"
-            done
-         done
-
-         mpg "$g" palette 8
-         mptrans "$g" palette 8
-
-         for b in 8 16
-         do
-            for c in gray gray-alpha rgb rgb-alpha
-            do
-               mpg "$g" "$c" "$b"
-            done
-            for c in gray rgb
-            do
-               mptrans "$g" "$c" "$b"
-            done
-         done
-      done;;
-
-   --coverage)
-      # Comments below indicate cases known to be required and not duplicated
-      # in other (required) cases; the aim is to get a minimal set that gives
-      # the maxium code coverage.
-      mpg none gray-alpha 8 # required: code coverage, sRGB opaque component
-      mpg none palette 8 # required: basic palette read
-      mpg 1.8 gray 2 # required: tests gamma threshold code
-      mpg 1.8 palette 2 # required: code coverage
-      mpg 1.8 palette 4 # required: code coverage
-      mpg 1.8 palette 8 # error limits only
-      mpg linear palette 8 # error limits only
-      mpg linear rgb-alpha 16 # error limits only
-      mpg sRGB palette 1 # required: code coverage
-      mpg sRGB rgb-alpha 16 # required: code coverage: pngread.c:2422 untested
-      :;;
-
-   *)
-      echo "$0 $1: unknown argument, usage:" >&2
-      echo "  $0 [--all|--coverage|--small]" >&2
-      exit 1
-esac
--- a/contrib/testpngs/palette-1-1.8-tRNS.png
+++ b/contrib/testpngs/palette-1-1.8-tRNS.png
--- a/contrib/testpngs/palette-1-1.8.png
+++ b/contrib/testpngs/palette-1-1.8.png
--- a/contrib/testpngs/palette-1-linear-tRNS.png
+++ b/contrib/testpngs/palette-1-linear-tRNS.png
--- a/contrib/testpngs/palette-1-linear.png
+++ b/contrib/testpngs/palette-1-linear.png
--- a/contrib/testpngs/palette-1-sRGB-tRNS.png
+++ b/contrib/testpngs/palette-1-sRGB-tRNS.png
--- a/contrib/testpngs/palette-1-sRGB.png
+++ b/contrib/testpngs/palette-1-sRGB.png
--- a/contrib/testpngs/palette-1-tRNS.png
+++ b/contrib/testpngs/palette-1-tRNS.png
--- a/contrib/testpngs/palette-1.png
+++ b/contrib/testpngs/palette-1.png
--- a/contrib/testpngs/palette-2-1.8-tRNS.png
+++ b/contrib/testpngs/palette-2-1.8-tRNS.png
--- a/contrib/testpngs/palette-2-1.8.png
+++ b/contrib/testpngs/palette-2-1.8.png
--- a/contrib/testpngs/palette-2-linear-tRNS.png
+++ b/contrib/testpngs/palette-2-linear-tRNS.png
--- a/contrib/testpngs/palette-2-linear.png
+++ b/contrib/testpngs/palette-2-linear.png
--- a/contrib/testpngs/palette-2-sRGB-tRNS.png
+++ b/contrib/testpngs/palette-2-sRGB-tRNS.png
--- a/contrib/testpngs/palette-2-sRGB.png
+++ b/contrib/testpngs/palette-2-sRGB.png
--- a/contrib/testpngs/palette-2-tRNS.png
+++ b/contrib/testpngs/palette-2-tRNS.png
--- a/contrib/testpngs/palette-2.png
+++ b/contrib/testpngs/palette-2.png
--- a/contrib/testpngs/palette-4-1.8-tRNS.png
+++ b/contrib/testpngs/palette-4-1.8-tRNS.png
--- a/contrib/testpngs/palette-4-1.8.png
+++ b/contrib/testpngs/palette-4-1.8.png
--- a/contrib/testpngs/palette-4-linear-tRNS.png
+++ b/contrib/testpngs/palette-4-linear-tRNS.png
--- a/contrib/testpngs/palette-4-linear.png
+++ b/contrib/testpngs/palette-4-linear.png
--- a/contrib/testpngs/palette-4-sRGB-tRNS.png
+++ b/contrib/testpngs/palette-4-sRGB-tRNS.png
--- a/contrib/testpngs/palette-4-sRGB.png
+++ b/contrib/testpngs/palette-4-sRGB.png
--- a/contrib/testpngs/palette-4-tRNS.png
+++ b/contrib/testpngs/palette-4-tRNS.png
--- a/Show More
+++ b/Show More