XFA: Upgrade libpng to 1.6.20.

third_party/libpng/png.h

 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.3 - July 18, 2013
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * libpng version 1.6.20, December 3, 2015
+ *
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
  * This code is released under the libpng license (See LICENSE, below)
  *
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
- *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.3 - July 18, 2013: Glenn
+ *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
+ *   libpng versions 0.97, January 1998, through 1.6.20, December 3, 2015:
+ *     Glenn Randers-Pehrson.
  *   See also "Contributing Authors", below.
- *
- * Note about libpng version numbers:
- *
- *   Due to various miscommunications, unforeseen code incompatibilities
- *   and occasional factors outside the authors' control, version numbering
- *   on the library has not always been consistent and straightforward.
- *   The following table summarizes matters since version 0.89c, which was
- *   the first widely used release:
- *
- *    source                 png.h  png.h  shared-lib
- *    version                string   int  version
- *    -------                ------ -----  ----------
- *    0.89c "1.0 beta 3"     0.89      89  1.0.89
- *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
- *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
- *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
- *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
- *    0.97c                  0.97      97  2.0.97
- *    0.98                   0.98      98  2.0.98
- *    0.99                   0.99      98  2.0.99
- *    0.99a-m                0.99      99  2.0.99
- *    1.00                   1.00     100  2.1.0 [100 should be 10000]
- *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
- *    1.0.1       png.h string is   10001  2.1.0
- *    1.0.1a-e    identical to the  10002  from here on, the shared library
- *    1.0.2       source version)   10002  is 2.V where V is the source code
- *    1.0.2a-b                      10003  version, except as noted.
- *    1.0.3                         10003
- *    1.0.3a-d                      10004
- *    1.0.4                         10004
- *    1.0.4a-f                      10005
- *    1.0.5 (+ 2 patches)           10005
- *    1.0.5a-d                      10006
- *    1.0.5e-r                      10100 (not source compatible)
- *    1.0.5s-v                      10006 (not binary compatible)
- *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
- *    1.0.6d-f                      10007 (still binary incompatible)
- *    1.0.6g                        10007
- *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
- *    1.0.6i                        10007  10.6i
- *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
- *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
- *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
- *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
- *    1.0.7                    1    10007  (still compatible)
- *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4
- *    1.0.8rc1                 1    10008  2.1.0.8rc1
- *    1.0.8                    1    10008  2.1.0.8
- *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6
- *    1.0.9rc1                 1    10009  2.1.0.9rc1
- *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10
- *    1.0.9rc2                 1    10009  2.1.0.9rc2
- *    1.0.9                    1    10009  2.1.0.9
- *    1.0.10beta1              1    10010  2.1.0.10beta1
- *    1.0.10rc1                1    10010  2.1.0.10rc1
- *    1.0.10                   1    10010  2.1.0.10
- *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3
- *    1.0.11rc1                1    10011  2.1.0.11rc1
- *    1.0.11                   1    10011  2.1.0.11
- *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2
- *    1.0.12rc1                2    10012  2.1.0.12rc1
- *    1.0.12                   2    10012  2.1.0.12
- *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)
- *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2
- *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5
- *    1.2.0rc1                 3    10200  3.1.2.0rc1
- *    1.2.0                    3    10200  3.1.2.0
- *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4
- *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2
- *    1.2.1                    3    10201  3.1.2.1
- *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6
- *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1
- *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1
- *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1
- *    1.0.13                  10    10013  10.so.0.1.0.13
- *    1.2.2                   12    10202  12.so.0.1.2.2
- *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6
- *    1.2.3                   12    10203  12.so.0.1.2.3
- *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3
- *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1
- *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1
- *    1.0.14                  10    10014  10.so.0.1.0.14
- *    1.2.4                   13    10204  12.so.0.1.2.4
- *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2
- *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3
- *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3
- *    1.0.15                  10    10015  10.so.0.1.0.15
- *    1.2.5                   13    10205  12.so.0.1.2.5
- *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4
- *    1.0.16                  10    10016  10.so.0.1.0.16
- *    1.2.6                   13    10206  12.so.0.1.2.6
- *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2
- *    1.0.17rc1               10    10017  12.so.0.1.0.17rc1
- *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
- *    1.0.17                  10    10017  12.so.0.1.0.17
- *    1.2.7                   13    10207  12.so.0.1.2.7
- *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5
- *    1.0.18rc1-5             10    10018  12.so.0.1.0.18rc1-5
- *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
- *    1.0.18                  10    10018  12.so.0.1.0.18
- *    1.2.8                   13    10208  12.so.0.1.2.8
- *    1.2.9beta1-3            13    10209  12.so.0.1.2.9beta1-3
- *    1.2.9beta4-11           13    10209  12.so.0.9[.0]
- *    1.2.9rc1                13    10209  12.so.0.9[.0]
- *    1.2.9                   13    10209  12.so.0.9[.0]
- *    1.2.10beta1-7           13    10210  12.so.0.10[.0]
- *    1.2.10rc1-2             13    10210  12.so.0.10[.0]
- *    1.2.10                  13    10210  12.so.0.10[.0]
- *    1.4.0beta1-5            14    10400  14.so.0.0[.0]
- *    1.2.11beta1-4           13    10211  12.so.0.11[.0]
- *    1.4.0beta7-8            14    10400  14.so.0.0[.0]
- *    1.2.11                  13    10211  12.so.0.11[.0]
- *    1.2.12                  13    10212  12.so.0.12[.0]
- *    1.4.0beta9-14           14    10400  14.so.0.0[.0]
- *    1.2.13                  13    10213  12.so.0.13[.0]
- *    1.4.0beta15-36          14    10400  14.so.0.0[.0]
- *    1.4.0beta37-87          14    10400  14.so.14.0[.0]
- *    1.4.0rc01               14    10400  14.so.14.0[.0]
- *    1.4.0beta88-109         14    10400  14.so.14.0[.0]
- *    1.4.0rc02-08            14    10400  14.so.14.0[.0]
- *    1.4.0                   14    10400  14.so.14.0[.0]
- *    1.4.1beta01-03          14    10401  14.so.14.1[.0]
- *    1.4.1rc01               14    10401  14.so.14.1[.0]
- *    1.4.1beta04-12          14    10401  14.so.14.1[.0]
- *    1.4.1                   14    10401  14.so.14.1[.0]
- *    1.4.2                   14    10402  14.so.14.2[.0]
- *    1.4.3                   14    10403  14.so.14.3[.0]
- *    1.4.4                   14    10404  14.so.14.4[.0]
- *    1.5.0beta01-58          15    10500  15.so.15.0[.0]
- *    1.5.0rc01-07            15    10500  15.so.15.0[.0]
- *    1.5.0                   15    10500  15.so.15.0[.0]
- *    1.5.1beta01-11          15    10501  15.so.15.1[.0]
- *    1.5.1rc01-02            15    10501  15.so.15.1[.0]
- *    1.5.1                   15    10501  15.so.15.1[.0]
- *    1.5.2beta01-03          15    10502  15.so.15.2[.0]
- *    1.5.2rc01-03            15    10502  15.so.15.2[.0]
- *    1.5.2                   15    10502  15.so.15.2[.0]
- *    1.5.3beta01-10          15    10503  15.so.15.3[.0]
- *    1.5.3rc01-02            15    10503  15.so.15.3[.0]
- *    1.5.3beta11             15    10503  15.so.15.3[.0]
- *    1.5.3 [omitted]
- *    1.5.4beta01-08          15    10504  15.so.15.4[.0]
- *    1.5.4rc01               15    10504  15.so.15.4[.0]
- *    1.5.4                   15    10504  15.so.15.4[.0]
- *    1.5.5beta01-08          15    10505  15.so.15.5[.0]
- *    1.5.5rc01               15    10505  15.so.15.5[.0]
- *    1.5.5                   15    10505  15.so.15.5[.0]
- *    1.5.6beta01-07          15    10506  15.so.15.6[.0]
- *    1.5.6rc01-03            15    10506  15.so.15.6[.0]
- *    1.5.6                   15    10506  15.so.15.6[.0]
- *    1.5.7beta01-05          15    10507  15.so.15.7[.0]
- *    1.5.7rc01-03            15    10507  15.so.15.7[.0]
- *    1.5.7                   15    10507  15.so.15.7[.0]
- *    1.6.0beta01-40          16    10600  16.so.16.0[.0]
- *    1.6.0rc01-08            16    10600  16.so.16.0[.0]
- *    1.6.0                   16    10600  16.so.16.0[.0]
- *    1.6.1beta01-09          16    10601  16.so.16.1[.0]
- *    1.6.1rc01               16    10601  16.so.16.1[.0]
- *    1.6.1                   16    10601  16.so.16.1[.0]
- *    1.6.2beta01             16    10602  16.so.16.2[.0]
- *    1.6.2rc01-06            16    10602  16.so.16.2[.0]
- *    1.6.2                   16    10602  16.so.16.2[.0]
- *    1.6.3beta01-11          16    10603  16.so.16.3[.0]
- *    1.6.3rc01               16    10603  16.so.16.3[.0]
- *    1.6.3                   16    10603  16.so.16.3[.0]
- *
- *   Henceforth the source version will match the shared-library major
- *   and minor numbers; the shared-library major version number will be
- *   used for changes in backward compatibility, as it is intended.  The
- *   PNG_LIBPNG_VER macro, which is not used within libpng but is available
- *   for applications, is an unsigned integer of the form xyyzz corresponding
- *   to the source version x.y.z (leading zeros in y and z).  Beta versions
- *   were given the previous public release number plus a letter, until
- *   version 1.0.6j; from then on they were given the upcoming public
- *   release number plus "betaNN" or "rcNN".
- *
- *   Binary incompatibility exists only when applications make direct access
- *   to the info_ptr or png_ptr members through png.h, and the compiled
- *   application is loaded with a different version of the library.
- *
- *   DLLNUM will change each time there are forward or backward changes
- *   in binary compatibility (e.g., when a new feature is added).
- *
- * See libpng-manual.txt or libpng.3 for more information.  The PNG
- * specification is available as a W3C Recommendation and as an ISO
- * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/
  */
 
 /*
  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
  *
  * If you modify libpng you may insert additional notices immediately following
  * this sentence.
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.3, July 18, 2013, are
- * Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are
- * distributed according to the same disclaimer and license as libpng-1.2.5
- * with the following individual added to the list of Contributing Authors:
- *
- *    Cosmin Truta
- *
- * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
- * Copyright (c) 2000-2002 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:
+ * 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:
  *
  *    Simon-Pierre Cadieux
  *    Eric S. Raymond
+ *    Mans Rullgard
+ *    Cosmin Truta
  *    Gilles Vollant
+ *    James Yu
  *
  * and with the following additions to the disclaimer:
  *
  *    There is no warranty against interference with your enjoyment of the
  *    library or against infringement.  There is no warranty that our
  *    efforts or the library will fulfill any of your particular purposes
  *    or needs.  This library is provided with all faults, and the entire
  *    risk of satisfactory quality, performance, accuracy, and effort is with
  *    the user.
  *
  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
- * Copyright (c) 1998, 1999, 2000 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:
+ * 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:
  *
  *    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
- * 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, 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:
  *
  *    John Bowler
  *    Kevin Bracey
  *    Sam Bushell
  *    Magnus Holmgren
  *    Greg Roelofs
  *    Tom Tanner
  *
  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
  *
  * For the purposes of this copyright and license, "Contributing Authors"
  * is defined as the following set of individuals:
  *
  *    Andreas Dilger
  *    Dave Martindale
  *    Guy Eric Schalnat
  *    Paul Schmidt
  *    Tim Wegner
  *
  * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
  * and Group 42, Inc. disclaim all warranties, expressed or implied,
  * including, without limitation, the warranties of merchantability and of
  * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
  * assume no liability for direct, indirect, incidental, special, exemplary,
  * or consequential damages, which may result from the use of the PNG
  * Reference Library, even if advised of the possibility of such damage.
  *
  * Permission is hereby granted to use, copy, modify, and distribute this
  * source code, or portions hereof, for any purpose, without fee, subject
  * to the following restrictions:
  *
  *   1. The origin of this source code must not be misrepresented.
  *
  *   2. Altered versions must be plainly marked as such and must not
  *      be misrepresented as being the original source.
  *
- *   3. This Copyright notice may not be removed or altered from
- *      any source or altered source distribution.
+ *   3. This Copyright notice may not be removed or altered from any
+ *      source or altered source distribution.
  *
  * The Contributing Authors and Group 42, Inc. specifically permit, without
  * fee, and encourage the use of this source code as a component to
  * supporting the PNG file format in commercial products.  If you use this
  * source code in a product, acknowledgment is not required but would be
  * appreciated.
+ *
+ * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
  */
 
 /*
  * 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).
  */
 
 /*
- * Libpng is OSI Certified Open Source Software.  OSI Certified is a
- * certification mark of the Open Source Initiative.
+ * Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
+ * a certification mark of the Open Source Initiative. OSI has not addressed
+ * the additional disclaimers inserted at version 1.0.7.
  */
 
 /*
  * The contributing authors would like to thank all those who helped
  * with testing, bug fixes, and patience.  This wouldn't have been
  * possible without all of you.
  *
  * Thanks to Frank J. T. Wojcik for helping with the documentation.
  */
 
+/* Note about libpng version numbers:
+ *
+ *    Due to various miscommunications, unforeseen code incompatibilities
+ *    and occasional factors outside the authors' control, version numbering
+ *    on the library has not always been consistent and straightforward.
+ *    The following table summarizes matters since version 0.89c, which was
+ *    the first widely used release:
+ *
+ *    source                 png.h  png.h  shared-lib
+ *    version                string   int  version
+ *    -------                ------ -----  ----------
+ *    0.89c "1.0 beta 3"     0.89      89  1.0.89
+ *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
+ *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
+ *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
+ *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
+ *    0.97c                  0.97      97  2.0.97
+ *    0.98                   0.98      98  2.0.98
+ *    0.99                   0.99      98  2.0.99
+ *    0.99a-m                0.99      99  2.0.99
+ *    1.00                   1.00     100  2.1.0 [100 should be 10000]
+ *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
+ *    1.0.1       png.h string is   10001  2.1.0
+ *    1.0.1a-e    identical to the  10002  from here on, the shared library
+ *    1.0.2       source version)   10002  is 2.V where V is the source code
+ *    1.0.2a-b                      10003  version, except as noted.
+ *    1.0.3                         10003
+ *    1.0.3a-d                      10004
+ *    1.0.4                         10004
+ *    1.0.4a-f                      10005
+ *    1.0.5 (+ 2 patches)           10005
+ *    1.0.5a-d                      10006
+ *    1.0.5e-r                      10100 (not source compatible)
+ *    1.0.5s-v                      10006 (not binary compatible)
+ *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
+ *    1.0.6d-f                      10007 (still binary incompatible)
+ *    1.0.6g                        10007
+ *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
+ *    1.0.6i                        10007  10.6i
+ *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
+ *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
+ *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
+ *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
+ *    1.0.7                    1    10007  (still compatible)
+ *    ...
+ *    1.0.19                  10    10019  10.so.0.19[.0]
+ *    ...
+ *    1.2.53                  13    10253  12.so.0.53[.0]
+ *    ...
+ *    1.5.23                  15    10523  15.so.15.23[.0]
+ *    ...
+ *    1.6.20                  16    10620  16.so.16.20[.0]
+ *
+ *    Henceforth the source version will match the shared-library major
+ *    and minor numbers; the shared-library major version number will be
+ *    used for changes in backward compatibility, as it is intended.  The
+ *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
+ *    for applications, is an unsigned integer of the form xyyzz corresponding
+ *    to the source version x.y.z (leading zeros in y and z).  Beta versions
+ *    were given the previous public release number plus a letter, until
+ *    version 1.0.6j; from then on they were given the upcoming public
+ *    release number plus "betaNN" or "rcNN".
+ *
+ *    Binary incompatibility exists only when applications make direct access
+ *    to the info_ptr or png_ptr members through png.h, and the compiled
+ *    application is loaded with a different version of the library.
+ *
+ *    DLLNUM will change each time there are forward or backward changes
+ *    in binary compatibility (e.g., when a new feature is added).
+ *
+ * See libpng.txt or libpng.3 for more information.  The PNG specification
+ * is available as a W3C Recommendation and as an ISO Specification,
+ * <http://www.w3.org/TR/2003/REC-PNG-20031110/
+ */
+
 /*
  * Y2K compliance in libpng:
  * =========================
  *
- *    July 18, 2013
+ *    December 3, 2015
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.6.3 are Y2K compliant.  It is my belief that
+ *    upward through 1.6.20 are Y2K compliant.  It is my belief that
  *    earlier versions were also Y2K compliant.
  *
  *    Libpng only has two year fields.  One is a 2-byte unsigned integer
  *    that will hold years up to 65535.  The other, which is deprecated,
  *    holds the date in text format, and will hold years up to 9999.
  *
  *    The integer is
  *        "png_uint_16 year" in png_time_struct.
  *
  *    The string is
@@ skipping 32 matching lines @@
  *       libpng maintainer
  *       PNG Development Group
  */
 
 #ifndef PNG_H
 #define PNG_H
 
 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
  * describes how to use libpng, and the file example.c summarizes it
  * with some code on which to build.  This file is useful for looking
- * at the actual function definitions and structure components.
+ * at the actual function definitions and structure components.  If that
+ * file has been stripped from your copy of libpng, you can find it at
+ * <http://www.libpng.org/pub/png/libpng-manual.txt>
  *
  * If you just need to read a PNG file and don't want to read the documentation
  * skip to the end of this file and read the section entitled 'simplified API'.
  */
 
-/* Sunliang.liu add 20100319 for avoid name conflict. */
-#define png_set_sig_bytes FOXIT_png_set_sig_bytes
-#define png_sig_cmp FOXIT_png_sig_cmp
-#define png_create_info_struct FOXIT_png_create_info_struct
-#define png_destroy_info_struct FOXIT_png_destroy_info_struct
-#define png_info_init_3 FOXIT_png_info_init_3
-#define png_data_freer FOXIT_png_data_freer
-#define png_free_data FOXIT_png_free_data
-#define png_info_destroy FOXIT_png_info_destroy
-#define png_get_io_ptr FOXIT_png_get_io_ptr
-#define png_init_io FOXIT_png_init_io
-#define png_convert_to_rfc1123 FOXIT_png_convert_to_rfc1123
-#define png_get_copyright FOXIT_png_get_copyright
-#define png_get_libpng_ver FOXIT_png_get_libpng_ver
-#define png_get_header_ver FOXIT_png_get_header_ver
-#define png_get_header_version FOXIT_png_get_header_version
-#define png_handle_as_unknown FOXIT_png_handle_as_unknown
-#define png_reset_zstream FOXIT_png_reset_zstream
-#define png_access_version_number FOXIT_png_access_version_number
-#define png_mmx_support FOXIT_png_mmx_support
-#define png_create_read_struct FOXIT_png_create_read_struct
-#define png_create_read_struct_2 FOXIT_png_create_read_struct_2
-#define png_create_write_struct FOXIT_png_create_write_struct
-#define png_create_write_struct_2 FOXIT_png_create_write_struct_2
-#define png_get_compression_buffer_size FOXIT_png_get_compression_buffer_size
-#define png_set_compression_buffer_size FOXIT_png_set_compression_buffer_size
-#define png_set_longjmp_fn FOXIT_png_set_longjmp_fn
-#define png_longjmp FOXIT_png_longjmp
-#define png_write_sig FOXIT_png_write_sig
-#define png_write_chunk FOXIT_png_write_chunk
-#define png_write_chunk_start FOXIT_png_write_chunk_start
-#define png_write_chunk_data FOXIT_png_write_chunk_data
-#define png_write_chunk_end FOXIT_png_write_chunk_end
-#define png_write_info_before_PLTE FOXIT_png_write_info_before_PLTE
-#define png_write_info FOXIT_png_write_info
-#define png_read_info FOXIT_png_read_info
-#define png_convert_to_rfc1123_buffer FOXIT_png_convert_to_rfc1123_buffer
-#define png_convert_from_struct_tm FOXIT_png_convert_from_struct_tm
-#define png_convert_from_time_t FOXIT_png_convert_from_time_t
-#define png_set_expand FOXIT_png_set_expand
-#define png_set_expand_gray_1_2_4_to_8 FOXIT_png_set_expand_gray_1_2_4_to_8
-#define png_set_palette_to_rgb FOXIT_png_set_palette_to_rgb
-#define png_set_tRNS_to_alpha FOXIT_png_set_tRNS_to_alpha
-#define png_set_expand_16 FOXIT_png_set_expand_16
-#define png_set_bgr FOXIT_png_set_bgr
-#define png_set_gray_to_rgb FOXIT_png_set_gray_to_rgb
-#define png_set_rgb_to_gray FOXIT_png_set_rgb_to_gray
-#define png_set_rgb_to_gray_fixed FOXIT_png_set_rgb_to_gray_fixed
-#define png_get_rgb_to_gray_status FOXIT_png_get_rgb_to_gray_status
-#define png_build_grayscale_palette FOXIT_png_build_grayscale_palette
-#define png_set_alpha_mode FOXIT_png_set_alpha_mode
-#define png_set_alpha_mode_fixed FOXIT_png_set_alpha_mode_fixed
-#define png_set_strip_alpha FOXIT_png_set_strip_alpha
-#define png_set_swap_alpha FOXIT_png_set_swap_alpha
-#define png_set_invert_alpha FOXIT_png_set_invert_alpha
-#define png_set_filler FOXIT_png_set_filler
-#define png_set_add_alpha FOXIT_png_set_add_alpha
-#define png_set_swap FOXIT_png_set_swap
-#define png_set_packing FOXIT_png_set_packing
-#define png_set_packswap FOXIT_png_set_packswap
-#define png_set_shift FOXIT_png_set_shift
-#define png_set_interlace_handling FOXIT_png_set_interlace_handling
-#define png_set_invert_mono FOXIT_png_set_invert_mono
-#define png_set_background FOXIT_png_set_background
-#define png_set_background_fixed FOXIT_png_set_background_fixed
-#define png_set_scale_16 FOXIT_png_set_scale_16
-#define png_set_quantize FOXIT_png_set_quantize
-#define png_set_gamma FOXIT_png_set_gamma
-#define png_set_gamma_fixed FOXIT_png_set_gamma_fixed
-#define png_set_flush FOXIT_png_set_flush
-#define png_write_flush FOXIT_png_write_flush
-#define png_start_read_image FOXIT_png_start_read_image
-#define png_read_update_info FOXIT_png_read_update_info
-#define png_read_rows FOXIT_png_read_rows
-#define png_read_row FOXIT_png_read_row
-#define png_read_image FOXIT_png_read_image
-#define png_write_row FOXIT_png_write_row
-#define png_write_rows FOXIT_png_write_rows
-#define png_write_image FOXIT_png_write_image
-#define png_write_end FOXIT_png_write_end
-#define png_read_end FOXIT_png_read_end
-#define png_destroy_read_struct FOXIT_png_destroy_read_struct
-#define png_destroy_write_struct FOXIT_png_destroy_write_struct
-#define png_set_crc_action FOXIT_png_set_crc_action
-#define png_set_filter FOXIT_png_set_filter
-#define png_set_filter_heuristics FOXIT_png_set_filter_heuristics
-#define png_set_filter_heuristics_fixed FOXIT_png_set_filter_heuristics_fixed
-#define png_set_compression_level FOXIT_png_set_compression_level
-#define png_set_compression_mem_level FOXIT_png_set_compression_mem_level
-#define png_set_compression_strategy FOXIT_png_set_compression_strategy
-#define png_set_compression_window_bits FOXIT_png_set_compression_window_bits
-#define png_set_compression_method FOXIT_png_set_compression_method
-#define png_set_text_compression_level FOXIT_png_set_text_compression_level
-#define png_set_text_compression_mem_level FOXIT_png_set_text_compression_mem_level
-#define png_set_text_compression_strategy FOXIT_png_set_text_compression_strategy
-#define png_set_text_compression_window_bits FOXIT_png_set_text_compression_window_bits
-#define png_set_text_compression_method FOXIT_png_set_text_compression_method
-#define png_set_error_fn FOXIT_png_set_error_fn
-#define png_get_error_ptr FOXIT_png_get_error_ptr
-#define png_set_write_fn FOXIT_png_set_write_fn
-#define png_set_read_fn FOXIT_png_set_read_fn
-#define png_set_read_status_fn FOXIT_png_set_read_status_fn
-#define png_set_write_status_fn FOXIT_png_set_write_status_fn
-#define png_set_read_user_transform_fn FOXIT_png_set_read_user_transform_fn
-#define png_set_write_user_transform_fn FOXIT_png_set_write_user_transform_fn
-#define png_set_user_transform_info FOXIT_png_set_user_transform_info
-#define png_get_user_transform_ptr FOXIT_png_get_user_transform_ptr
-#define png_get_current_row_number FOXIT_png_get_current_row_number
-#define png_get_current_pass_number FOXIT_png_get_current_pass_number
-#define png_set_read_user_chunk_fn FOXIT_png_set_read_user_chunk_fn
-#define png_get_user_chunk_ptr FOXIT_png_get_user_chunk_ptr
-#define png_set_progressive_read_fn FOXIT_png_set_progressive_read_fn
-#define png_get_progressive_ptr FOXIT_png_get_progressive_ptr
-#define png_process_data FOXIT_png_process_data
-#define png_process_data_pause FOXIT_png_process_data_pause
-#define png_process_data_skip FOXIT_png_process_data_skip
-#define png_progressive_combine_row FOXIT_png_progressive_combine_row
-#define png_calloc FOXIT_png_calloc
-#define png_error FOXIT_png_error
-#define png_chunk_error FOXIT_png_chunk_error
-#define png_err FOXIT_png_err
-#define png_warning FOXIT_png_warning
-#define png_chunk_warning FOXIT_png_chunk_warning
-#define png_benign_error FOXIT_png_benign_error
-#define png_chunk_benign_error FOXIT_png_chunk_benign_error
-#define png_set_benign_errors FOXIT_png_set_benign_errors
-#define png_get_valid FOXIT_png_get_valid
-#define png_get_rowbytes FOXIT_png_get_rowbytes
-#define png_get_rows FOXIT_png_get_rows
-#define png_set_rows FOXIT_png_set_rows
-#define png_get_channels FOXIT_png_get_channels
-#define png_get_image_width FOXIT_png_get_image_width
-#define png_get_image_height FOXIT_png_get_image_height
-#define png_get_bit_depth FOXIT_png_get_bit_depth
-#define png_get_color_type FOXIT_png_get_color_type
-#define png_get_filter_type FOXIT_png_get_filter_type
-#define png_get_interlace_type FOXIT_png_get_interlace_type
-#define png_get_compression_type FOXIT_png_get_compression_type
-#define png_get_pixels_per_meter FOXIT_png_get_pixels_per_meter
-#define png_get_x_pixels_per_meter FOXIT_png_get_x_pixels_per_meter
-#define png_get_y_pixels_per_meter FOXIT_png_get_y_pixels_per_meter
-#define png_get_pixel_aspect_ratio FOXIT_png_get_pixel_aspect_ratio
-#define png_get_pixel_aspect_ratio_fixed FOXIT_png_get_pixel_aspect_ratio_fixed
-#define png_get_x_offset_pixels FOXIT_png_get_x_offset_pixels
-#define png_get_y_offset_pixels FOXIT_png_get_y_offset_pixels
-#define png_get_x_offset_microns FOXIT_png_get_x_offset_microns
-#define png_get_y_offset_microns FOXIT_png_get_y_offset_microns
-#define png_get_signature FOXIT_png_get_signature
-#define png_get_bKGD FOXIT_png_get_bKGD
-#define png_set_bKGD FOXIT_png_set_bKGD
-#define png_get_cHRM FOXIT_png_get_cHRM
-#define png_get_cHRM_XYZ FOXIT_png_get_cHRM_XYZ
-#define png_get_cHRM_fixed FOXIT_png_get_cHRM_fixed
-#define png_get_cHRM_XYZ_fixed FOXIT_png_get_cHRM_XYZ_fixed
-#define png_set_cHRM FOXIT_png_set_cHRM
-#define png_set_cHRM_XYZ FOXIT_png_set_cHRM_XYZ
-#define png_set_cHRM_fixed FOXIT_png_set_cHRM_fixed
-#define png_set_cHRM_XYZ_fixed FOXIT_png_set_cHRM_XYZ_fixed
-#define png_get_gAMA FOXIT_png_get_gAMA
-#define png_set_gAMA FOXIT_png_set_gAMA
-#define png_set_gAMA_fixed FOXIT_png_set_gAMA_fixed
-#define png_get_hIST FOXIT_png_get_hIST
-#define png_set_hIST FOXIT_png_set_hIST
-#define png_get_IHDR FOXIT_png_get_IHDR
-#define png_set_IHDR FOXIT_png_set_IHDR
-#define png_get_oFFs FOXIT_png_get_oFFs
-#define png_set_oFFs FOXIT_png_set_oFFs
-#define png_get_pCAL FOXIT_png_get_pCAL
-#define png_set_pCAL FOXIT_png_set_pCAL
-#define png_set_pHYs FOXIT_png_set_pHYs
-#define png_get_PLTE FOXIT_png_get_PLTE
-#define png_set_PLTE FOXIT_png_set_PLTE
-#define png_get_sBIT FOXIT_png_get_sBIT
-#define png_set_sBIT FOXIT_png_set_sBIT
-#define png_get_sRGB FOXIT_png_get_sRGB
-#define png_set_sRGB FOXIT_png_set_sRGB
-#define png_set_sRGB_gAMA_and_cHRM FOXIT_png_set_sRGB_gAMA_and_cHRM
-#define png_get_iCCP FOXIT_png_get_iCCP
-#define png_set_iCCP FOXIT_png_set_iCCP
-#define png_get_sPLT FOXIT_png_get_sPLT
-#define png_set_sPLT FOXIT_png_set_sPLT
-#define png_get_text FOXIT_png_get_text
-#define png_set_text FOXIT_png_set_text
-#define png_get_tIME FOXIT_png_get_tIME
-#define png_set_tIME FOXIT_png_set_tIME
-#define png_get_tRNS FOXIT_png_get_tRNS
-#define png_set_tRNS FOXIT_png_set_tRNS
-#define png_get_sCAL FOXIT_png_get_sCAL
-#define png_get_sCAL_fixed FOXIT_png_get_sCAL_fixed
-#define png_get_sCAL_s FOXIT_png_get_sCAL_s
-#define png_set_sCAL FOXIT_png_set_sCAL
-#define png_set_sCAL_s FOXIT_png_set_sCAL_s
-#define png_set_keep_unknown_chunks FOXIT_png_set_keep_unknown_chunks
-#define png_set_unknown_chunks FOXIT_png_set_unknown_chunks
-#define png_set_unknown_chunk_location FOXIT_png_set_unknown_chunk_location
-#define png_get_unknown_chunks FOXIT_png_get_unknown_chunks
-#define png_set_invalid FOXIT_png_set_invalid
-#define png_read_png FOXIT_png_read_png
-#define png_write_png FOXIT_png_write_png
-#define png_permit_mng_features FOXIT_png_permit_mng_features
-#define png_set_strip_error_numbers FOXIT_png_set_strip_error_numbers
-#define png_set_user_limits FOXIT_png_set_user_limits
-#define png_get_user_width_max FOXIT_png_get_user_width_max
-#define png_get_user_height_max FOXIT_png_get_user_height_max
-#define png_set_chunk_cache_max FOXIT_png_set_chunk_cache_max
-#define png_get_chunk_cache_max FOXIT_png_get_chunk_cache_max
-#define png_set_chunk_malloc_max FOXIT_png_set_chunk_malloc_max
-#define png_get_chunk_malloc_max FOXIT_png_get_chunk_malloc_max
-#define png_get_pixels_per_inch FOXIT_png_get_pixels_per_inch
-#define png_get_x_pixels_per_inch FOXIT_png_get_x_pixels_per_inch
-#define png_get_y_pixels_per_inch FOXIT_png_get_y_pixels_per_inch
-#define png_get_x_offset_inches FOXIT_png_get_x_offset_inches
-#define png_get_x_offset_inches_fixed FOXIT_png_get_x_offset_inches_fixed
-#define png_get_y_offset_inches FOXIT_png_get_y_offset_inches
-#define png_get_y_offset_inches_fixed FOXIT_png_get_y_offset_inches_fixed
-#define png_get_pHYs_dpi FOXIT_png_get_pHYs_dpi
-#define png_get_io_state FOXIT_png_get_io_state
-#define png_get_io_chunk_name FOXIT_png_get_io_chunk_name
-#define png_get_io_chunk_type FOXIT_png_get_io_chunk_type
-#define png_get_uint_31 FOXIT_png_get_uint_31
-#define png_get_uint_32 FOXIT_png_get_uint_32
-#define png_get_uint_16 FOXIT_png_get_uint_16
-#define png_get_int_32 FOXIT_png_get_int_32
-#define png_save_uint_32 FOXIT_png_save_uint_32
-#define png_save_int_32 FOXIT_png_save_int_32
-#define png_save_uint_16 FOXIT_png_save_uint_16
-#define png_image_begin_read_from_file FOXIT_png_image_begin_read_from_file
-#define png_image_begin_read_from_stdio FOXIT_png_image_begin_read_from_stdio
-#define png_image_begin_read_from_memory FOXIT_png_image_begin_read_from_memory
-#define png_image_finish_read FOXIT_png_image_finish_read
-#define png_image_free FOXIT_png_image_free
-#define png_image_write_to_file FOXIT_png_image_write_to_file
-#define png_image_write_to_stdio FOXIT_png_image_write_to_stdio
-#define png_set_check_for_invalid_index FOXIT_png_set_check_for_invalid_index
-#define png_get_palette_max FOXIT_png_get_palette_max
-#define png_set_option FOXIT_png_set_option
-
-#define png_set_strip_16 FOXIT_png_set_strip_16
-#define png_64bit_product FOXIT_png_64bit_product
-#define png_check_cHRM_fixed FOXIT_png_check_cHRM_fixed
-#define png_free FOXIT_png_free
-#define png_free_default FOXIT_png_free_default
-#define png_get_mem_ptr FOXIT_png_get_mem_ptr
-#define png_malloc FOXIT_png_malloc
-#define png_malloc_default FOXIT_png_malloc_default
-#define png_malloc_warn FOXIT_png_malloc_warn
-#define png_memcpy_check FOXIT_png_memcpy_check
-#define png_memset_check FOXIT_png_memset_check
-#define png_pass_dsp_mask FOXIT_png_pass_dsp_mask
-#define png_pass_inc FOXIT_png_pass_inc
-#define png_pass_mask FOXIT_png_pass_mask
-#define png_pass_start FOXIT_png_pass_start
-#define png_pass_yinc FOXIT_png_pass_yinc
-#define png_pass_ystart FOXIT_png_pass_ystart
-#define png_set_mem_fn FOXIT_png_set_mem_fn
-
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.3"
+#define PNG_LIBPNG_VER_STRING "1.6.20"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.3 - July 18, 2013\n"
+     " libpng version 1.6.20 - December 3, 2015\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
 
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 3
+#define PNG_LIBPNG_VER_RELEASE 20
 
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
 
 #define PNG_LIBPNG_VER_BUILD  0
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
 #define PNG_LIBPNG_BUILD_BETA     2
@@ skipping 10 matching lines @@
                                        PNG_LIBPNG_BUILD_PRIVATE */
 
 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
 
 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  * We must not include leading zeros.
  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
-#define PNG_LIBPNG_VER 10603 /* 1.6.3 */
+#define PNG_LIBPNG_VER 10620 /* 1.6.20 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
  */
 #ifndef PNGLCONF_H
     /* If pnglibconf.h is missing, you can
      * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
      */
 #   include "pnglibconf.h"
 #endif
@@ skipping 36 matching lines @@
 extern "C" {
 #endif /* __cplusplus */
 
 /* Version information for C files, stored in png.c.  This had better match
  * the version above.
  */
 #define png_libpng_ver png_get_header_ver(NULL)
 
 /* This file is arranged in several sections:
  *
- * 1. Any configuration options that can be specified by for the application
+ * 1. [omitted]
+ * 2. Any configuration options that can be specified by for the application
  *    code when it is built.  (Build time configuration is in pnglibconf.h)
- * 2. Type definitions (base types are defined in pngconf.h), structure
+ * 3. Type definitions (base types are defined in pngconf.h), structure
  *    definitions.
- * 3. Exported library functions.
- * 4. Simplified API.
+ * 4. Exported library functions.
+ * 5. Simplified API.
+ * 6. Implementation options.
  *
  * The library source code has additional files (principally pngpriv.h) that
  * allow configuration of the library.
  */
-/* Section 1: run time configuration
+
+/* Section 1: [omitted] */
+
+/* Section 2: run time configuration
  * See pnglibconf.h for build time configuration
  *
  * Run time configuration allows the application to choose between
  * implementations of certain arithmetic APIs.  The default is set
  * at build time and recorded in pnglibconf.h, but it is safe to
  * override these (and only these) settings.  Note that this won't
  * change what the library does, only application code, and the
  * settings can (and probably should) be made on a per-file basis
  * by setting the #defines before including png.h
  *
  * Use macros to read integers from PNG data or use the exported
  * functions?
  *   PNG_USE_READ_MACROS: use the macros (see below)  Note that
  *     the macros evaluate their argument multiple times.
  *   PNG_NO_USE_READ_MACROS: call the relevant library function.
  *
  * Use the alternative algorithm for compositing alpha samples that
  * does not use division?
  *   PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
  *      algorithm.
  *   PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
  *
  * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
  * false?
  *   PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
  *      APIs to png_warning.
  * Otherwise the calls are mapped to png_error.
  */
 
-/* Section 2: type definitions, including structures and compile time
+/* Section 3: type definitions, including structures and compile time
  * constants.
  * See pngconf.h for base types that vary by machine/system
  */
 
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_6_3;
+typedef char* png_libpng_version_1_6_20;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
  * png_struct is the cache of information used while reading or writing a single
  * PNG file.  One of these is always required, although the simplified API
  * (below) hides the creation and destruction of it.
  */
 typedef struct png_struct_def png_struct;
 typedef const png_struct * png_const_structp;
 typedef png_struct * png_structp;
@@ skipping 161 matching lines @@
    png_byte month;   /* month of year, 1 - 12 */
    png_byte day;     /* day of month, 1 - 31 */
    png_byte hour;    /* hour of day, 0 - 23 */
    png_byte minute;  /* minute of hour, 0 - 59 */
    png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
 } png_time;
 typedef png_time * png_timep;
 typedef const png_time * png_const_timep;
 typedef png_time * * png_timepp;
 
-#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
+   defined(PNG_USER_CHUNKS_SUPPORTED)
 /* png_unknown_chunk is a structure to hold queued chunks for which there is
  * no specific support.  The idea is that we can use this to queue
  * up private chunks for output even though the library doesn't actually
  * know about their semantics.
  *
  * The data in the structure is set by libpng on read and used on write.
  */
 typedef struct png_unknown_chunk_t
 {
     png_byte name[5]; /* Textual chunk name with '\0' terminator */
@@ skipping 112 matching lines @@
 #define PNG_INFO_bKGD 0x0020
 #define PNG_INFO_hIST 0x0040
 #define PNG_INFO_pHYs 0x0080
 #define PNG_INFO_oFFs 0x0100
 #define PNG_INFO_tIME 0x0200
 #define PNG_INFO_pCAL 0x0400
 #define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
 #define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
 #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
 #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
+#if INT_MAX >= 0x8000 /* else this might break */
 #define PNG_INFO_IDAT 0x8000   /* ESR, 1.0.6 */
+#endif
 
 /* This is used for the transformation routines, as some of them
  * change these values for the row.  It also should enable using
  * the routines for other purposes.
  */
 typedef struct png_row_info_struct
 {
    png_uint_32 width;    /* width of row */
    png_size_t rowbytes;  /* number of bytes in row */
    png_byte color_type;  /* color type of row */
@@ skipping 83 matching lines @@
 #define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
 #define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
 #define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* write only */
 /* Added to libpng-1.2.34 */
 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
 /* Added to libpng-1.4.0 */
 #define PNG_TRANSFORM_GRAY_TO_RGB   0x2000      /* read only */
 /* Added to libpng-1.5.4 */
 #define PNG_TRANSFORM_EXPAND_16     0x4000      /* read only */
+#if INT_MAX >= 0x8000 /* else this might break */
 #define PNG_TRANSFORM_SCALE_16      0x8000      /* read only */
+#endif
 
 /* Flags for MNG supported features */
 #define PNG_FLAG_MNG_EMPTY_PLTE     0x01
 #define PNG_FLAG_MNG_FILTER_64      0x04
 #define PNG_ALL_MNG_FEATURES        0x05
 
 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
  * this allowed the zlib default functions to be used on Windows
  * platforms.  In 1.5 the zlib default malloc (which just calls malloc and
  * ignores the first argument) should be completely compatible with the
  * following.
  */
 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
     png_alloc_size_t));
 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
 
-/* Section 3: exported functions
+/* Section 4: exported functions
  * Here are the function definitions most commonly used.  This is not
  * the place to find out how to use libpng.  See libpng-manual.txt for the
  * full explanation, see example.c for the summary.  This just provides
  * a simple one line description of the use of each function.
  *
  * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
  * pngconf.h and in the *.dfn files in the scripts directory.
  *
  *   PNG_EXPORT(ordinal, type, name, (args));
  *
@@ skipping 155 matching lines @@
     png_const_timep ptime));
 #endif
 
 #ifdef PNG_CONVERT_tIME_SUPPORTED
 /* Convert from a struct tm to png_time */
 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
     const struct tm * ttime));
 
 /* Convert from time_t to png_time.  Uses gmtime() */
 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
-#endif /* PNG_CONVERT_tIME_SUPPORTED */
+#endif /* CONVERT_tIME */
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
 #endif
 
 #ifdef PNG_READ_EXPAND_16_SUPPORTED
@@ skipping 28 matching lines @@
 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
     png_ptr));
 #endif
 
 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
     png_colorp palette));
 #endif
 
 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
-/* How the alpha channel is interpreted - this affects how the color channels of
- * a PNG file are returned when an alpha channel, or tRNS chunk in a palette
- * file, is present.
+/* How the alpha channel is interpreted - this affects how the color channels
+ * of a PNG file are returned to the calling application when an alpha channel,
+ * or a tRNS chunk in a palette file, is present.
  *
  * This has no effect on the way pixels are written into a PNG output
  * datastream. The color samples in a PNG datastream are never premultiplied
  * with the alpha samples.
  *
  * The default is to return data according to the PNG specification: the alpha
  * channel is a linear measure of the contribution of the pixel to the
- * corresponding composited pixel.  The gamma encoded color channels must be
- * scaled according to the contribution and to do this it is necessary to undo
+ * corresponding composited pixel, and the color channels are unassociated
+ * (not premultiplied).  The gamma encoded color channels must be scaled
+ * according to the contribution and to do this it is necessary to undo
  * the encoding, scale the color values, perform the composition and reencode
  * the values.  This is the 'PNG' mode.
  *
  * The alternative is to 'associate' the alpha with the color information by
- * storing color channel values that have been scaled by the alpha.  The
- * advantage is that the color channels can be resampled (the image can be
- * scaled) in this form.  The disadvantage is that normal practice is to store
- * linear, not (gamma) encoded, values and this requires 16-bit channels for
- * still images rather than the 8-bit channels that are just about sufficient if
- * gamma encoding is used.  In addition all non-transparent pixel values,
- * including completely opaque ones, must be gamma encoded to produce the final
- * image.  This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the
- * latter being the two common names for associated alpha color channels.)
+ * storing color channel values that have been scaled by the alpha.
+ * image.  These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
+ * (the latter being the two common names for associated alpha color channels).
  *
- * Since it is not necessary to perform arithmetic on opaque color values so
- * long as they are not to be resampled and are in the final color space it is
- * possible to optimize the handling of alpha by storing the opaque pixels in
- * the PNG format (adjusted for the output color space) while storing partially
- * opaque pixels in the standard, linear, format.  The accuracy required for
- * standard alpha composition is relatively low, because the pixels are
- * isolated, therefore typically the accuracy loss in storing 8-bit linear
- * values is acceptable.  (This is not true if the alpha channel is used to
- * simulate transparency over large areas - use 16 bits or the PNG mode in
- * this case!)  This is the 'OPTIMIZED' mode.  For this mode a pixel is
- * treated as opaque only if the alpha value is equal to the maximum value.
+ * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
+ * value is equal to the maximum value.
  *
  * The final choice is to gamma encode the alpha channel as well.  This is
  * broken because, in practice, no implementation that uses this choice
  * correctly undoes the encoding before handling alpha composition.  Use this
  * choice only if other serious errors in the software or hardware you use
  * mandate it; the typical serious error is for dark halos to appear around
  * opaque areas of the composited PNG image because of arithmetic overflow.
  *
  * The API function png_set_alpha_mode specifies which of these choices to use
  * with an enumerated 'mode' value and the gamma of the required output:
  */
 #define PNG_ALPHA_PNG           0 /* according to the PNG standard */
 #define PNG_ALPHA_STANDARD      1 /* according to Porter/Duff */
 #define PNG_ALPHA_ASSOCIATED    1 /* as above; this is the normal practice */
 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
 #define PNG_ALPHA_OPTIMIZED     2 /* 'PNG' for opaque pixels, else 'STANDARD' */
 #define PNG_ALPHA_BROKEN        3 /* the alpha channel is gamma encoded */
 
 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
     double output_gamma))
 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
     int mode, png_fixed_point output_gamma))
 #endif
 
 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
 /* The output_gamma value is a screen gamma in libpng terminology: it expresses
- * how to decode the output values, not how they are encoded.  The values used
- * correspond to the normal numbers used to describe the overall gamma of a
- * computer display system; for example 2.2 for an sRGB conformant system.  The
- * values are scaled by 100000 in the _fixed version of the API (so 220000 for
- * sRGB.)
- *
- * The inverse of the value is always used to provide a default for the PNG file
- * encoding if it has no gAMA chunk and if png_set_gamma() has not been called
- * to override the PNG gamma information.
- *
- * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
- * opaque pixels however pixels with lower alpha values are not encoded,
- * regardless of the output gamma setting.
- *
- * When the standard Porter Duff handling is requested with mode 1 the output
- * encoding is set to be linear and the output_gamma value is only relevant
- * as a default for input data that has no gamma information.  The linear output
- * encoding will be overridden if png_set_gamma() is called - the results may be
- * highly unexpected!
- *
- * The following numbers are derived from the sRGB standard and the research
- * behind it.  sRGB is defined to be approximated by a PNG gAMA chunk value of
- * 0.45455 (1/2.2) for PNG.  The value implicitly includes any viewing
- * correction required to take account of any differences in the color
- * environment of the original scene and the intended display environment; the
- * value expresses how to *decode* the image for display, not how the original
- * data was *encoded*.
- *
- * sRGB provides a peg for the PNG standard by defining a viewing environment.
- * sRGB itself, and earlier TV standards, actually use a more complex transform
- * (a linear portion then a gamma 2.4 power law) than PNG can express.  (PNG is
- * limited to simple power laws.)  By saying that an image for direct display on
- * an sRGB conformant system should be stored with a gAMA chunk value of 45455
- * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
- * makes it possible to derive values for other display systems and
- * environments.
- *
- * The Mac value is deduced from the sRGB based on an assumption that the actual
- * extra viewing correction used in early Mac display systems was implemented as
- * a power 1.45 lookup table.
- *
- * Any system where a programmable lookup table is used or where the behavior of
- * the final display device characteristics can be changed requires system
- * specific code to obtain the current characteristic.  However this can be
- * difficult and most PNG gamma correction only requires an approximate value.
- *
- * By default, if png_set_alpha_mode() is not called, libpng assumes that all
- * values are unencoded, linear, values and that the output device also has a
- * linear characteristic.  This is only very rarely correct - it is invariably
- * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
- * default if you don't know what the right answer is!
- *
- * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
- * 10.6) which used a correction table to implement a somewhat lower gamma on an
- * otherwise sRGB system.
- *
- * Both these values are reserved (not simple gamma values) in order to allow
- * more precise correction internally in the future.
- *
- * NOTE: the following values can be passed to either the fixed or floating
- * point APIs, but the floating point API will also accept floating point
- * values.
+ * how to decode the output values, not how they are encoded.
  */
 #define PNG_DEFAULT_sRGB -1       /* sRGB gamma and color space */
 #define PNG_GAMMA_MAC_18 -2       /* Old Mac '1.8' gamma and color space */
 #define PNG_GAMMA_sRGB   220000   /* Television standards--matches sRGB gamma */
 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
 #endif
 
 /* The following are examples of calls to png_set_alpha_mode to achieve the
  * required overall gamma correction and, where necessary, alpha
  * premultiplication.
@@ skipping 78 matching lines @@
     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
 #endif
 
 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
     defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
 #endif
 
 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
-/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
+/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
     int flags));
 /* The values of the PNG_FILLER_ defines should NOT be changed */
 #  define PNG_FILLER_BEFORE 0
 #  define PNG_FILLER_AFTER 1
-/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
+/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
     png_uint_32 filler, int flags));
-#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
+#endif /* READ_FILLER || WRITE_FILLER */
 
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
 /* Swap bytes in 16-bit depth files. */
 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
 #endif
 
 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
 #endif
@@ skipping 169 matching lines @@
  *
  *      value                       action:critical     action:ancillary
  */
 #define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
 #define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
 #define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
 #define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
 #define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
 #define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
 
+#ifdef PNG_WRITE_SUPPORTED
 /* These functions give the user control over the scan-line filtering in
  * libpng and the compression methods used by zlib.  These functions are
  * mainly useful for testing, as the defaults should work with most users.
  * Those users who are tight on memory or want faster performance at the
  * expense of compression can modify them.  See the compression library
  * header file (zlib.h) for an explination of the compression functions.
  */
 
 /* Set the filtering method(s) used by libpng.  Currently, the only valid
  * value for "method" is 0.
  */
 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
     int filters));
+#endif /* WRITE */
 
 /* Flags for png_set_filter() to say which filters to use.  The flags
  * are chosen so that they don't conflict with real filter types
  * below, in case they are supplied instead of the #defined constants.
  * These values should NOT be changed.
  */
 #define PNG_NO_FILTERS     0x00
 #define PNG_FILTER_NONE    0x08
 #define PNG_FILTER_SUB     0x10
 #define PNG_FILTER_UP      0x20
 #define PNG_FILTER_AVG     0x40
 #define PNG_FILTER_PAETH   0x80
 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
                          PNG_FILTER_AVG | PNG_FILTER_PAETH)
 
 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
  * These defines should NOT be changed.
  */
 #define PNG_FILTER_VALUE_NONE  0
 #define PNG_FILTER_VALUE_SUB   1
 #define PNG_FILTER_VALUE_UP    2
 #define PNG_FILTER_VALUE_AVG   3
 #define PNG_FILTER_VALUE_PAETH 4
 #define PNG_FILTER_VALUE_LAST  5
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
-/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
- * defines, either the default (minimum-sum-of-absolute-differences), or
- * the experimental method (weighted-minimum-sum-of-absolute-differences).
- *
- * Weights are factors >= 1.0, indicating how important it is to keep the
- * filter type consistent between rows.  Larger numbers mean the current
- * filter is that many times as likely to be the same as the "num_weights"
- * previous filters.  This is cumulative for each previous row with a weight.
- * There needs to be "num_weights" values in "filter_weights", or it can be
- * NULL if the weights aren't being specified.  Weights have no influence on
- * the selection of the first row filter.  Well chosen weights can (in theory)
- * improve the compression for a given image.
- *
- * Costs are factors >= 1.0 indicating the relative decoding costs of a
- * filter type.  Higher costs indicate more decoding expense, and are
- * therefore less likely to be selected over a filter with lower computational
- * costs.  There needs to be a value in "filter_costs" for each valid filter
- * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
- * setting the costs.  Costs try to improve the speed of decompression without
- * unduly increasing the compressed image size.
- *
- * A negative weight or cost indicates the default value is to be used, and
- * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
- * The default values for both weights and costs are currently 1.0, but may
- * change if good general weighting/cost heuristics can be found.  If both
- * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
- * to the UNWEIGHTED method, but with added encoding time/computation.
- */
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
     int heuristic_method, int num_weights, png_const_doublep filter_weights,
     png_const_doublep filter_costs))
 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
     (png_structrp png_ptr, int heuristic_method, int num_weights,
     png_const_fixed_point_p filter_weights,
     png_const_fixed_point_p filter_costs))
-#endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+#endif /* WRITE_WEIGHTED_FILTER */
 
-/* Heuristic used for row filter selection.  These defines should NOT be
- * changed.
- */
+/* The following are no longer used and will be removed from libpng-1.7: */
 #define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
 #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
 #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
 
-#ifdef PNG_WRITE_SUPPORTED
 /* Set the library compression level.  Currently, valid values range from
  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
  * shown that zlib compression levels 3-6 usually perform as well as level 9
  * for PNG images, and do considerably fewer caclulations.  In the future,
  * these values may not correspond directly to the zlib compression levels.
  */
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
     int level));
 
 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
     int mem_level));
 
 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
     int strategy));
 
 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
  * smaller value of window_bits if it can do so safely.
  */
 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
     int window_bits));
 
 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
     int method));
-#endif
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
 
 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 /* Also set zlib parameters for compressing non-IDAT chunks */
 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
     int level));
 
 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
     int mem_level));
 
 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
     int strategy));
 
 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
  * smaller value of window_bits if it can do so safely.
  */
 PNG_EXPORT(225, void, png_set_text_compression_window_bits,
     (png_structrp png_ptr, int window_bits));
 
 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
     int method));
-#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
+#endif /* WRITE */
 
 /* These next functions are called for input/output, memory, and error
  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
  * and call standard C I/O routines such as fread(), fwrite(), and
  * fprintf().  These functions can be made to use other I/O routines
  * at run time for those applications that need to handle I/O in a
  * different manner by calling png_set_???_fn().  See libpng-manual.txt for
  * more information.
  */
 
@@ skipping 90 matching lines @@
  * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
  * chunks to be treated as unknown, however in this case the callback must do
  * any processing required by the chunk (e.g. by calling the appropriate
  * png_set_ APIs.)
  *
  * There is no write support - on write, by default, all the chunks in the
  * 'unknown' list are written in the specified position.
  *
  * The integer return from the callback function is interpreted thus:
  *
- * negative: An error occured, png_chunk_error will be called.
+ * negative: An error occurred; png_chunk_error will be called.
  *     zero: The chunk was not handled, the chunk will be saved. A critical
  *           chunk will cause an error at this point unless it is to be saved.
  * positive: The chunk was handled, libpng will ignore/discard it.
  *
  * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about
  * how this behavior will change in libpng 1.7
  */
 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
     png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
 #endif
@@ skipping 28 matching lines @@
 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save));
 
 /* A function which may be called *only* outside (after) a call to
  * png_process_data.  It returns the number of bytes of data to skip in the
  * input.  Normally it will return 0, but if it returns a non-zero value the
  * application must skip than number of bytes of input data and pass the
  * following data to the next call to png_process_data.
  */
 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
 
-#ifdef PNG_READ_INTERLACING_SUPPORTED
 /* Function that combines rows.  'new_row' is a flag that should come from
  * the callback and be non-NULL if anything needs to be done; the library
  * stores its own version of the new data internally and ignores the passed
  * in value.
  */
 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
     png_bytep old_row, png_const_bytep new_row));
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PROGRESSIVE_READ */
 
 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
     png_alloc_size_t size), PNG_ALLOCATED);
 /* Added at libpng version 1.4.0 */
 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
     png_alloc_size_t size), PNG_ALLOCATED);
 
 /* Added at libpng version 1.2.4 */
 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
     png_alloc_size_t size), PNG_ALLOCATED);
 
 /* Frees a pointer allocated by png_malloc() */
 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
 
 /* Free data that was allocated internally */
 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 free_me, int num));
 
 /* Reassign responsibility for freeing existing data, whether allocated
  * by libpng or by the application; this works on the png_info structure passed
  * in, it does not change the state for other png_info structures.
  *
  * It is unlikely that this function works correctly as of 1.6.0 and using it
  * may result either in memory leaks or double free of allocated data.
  */
-PNG_EXPORTA(99, void, png_data_freer, (png_const_structrp png_ptr,
-    png_inforp info_ptr, int freer, png_uint_32 mask), PNG_DEPRECATED);
+PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
+    png_inforp info_ptr, int freer, png_uint_32 mask));
 
 /* Assignments for png_data_freer */
 #define PNG_DESTROY_WILL_FREE_DATA 1
 #define PNG_SET_WILL_FREE_DATA 1
 #define PNG_USER_WILL_FREE_DATA 2
 /* Flags for png_ptr->free_me and info_ptr->free_me */
 #define PNG_FREE_HIST 0x0008
 #define PNG_FREE_ICCP 0x0010
 #define PNG_FREE_SPLT 0x0020
 #define PNG_FREE_ROWS 0x0040
@@ skipping 21 matching lines @@
 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
     png_const_charp error_message), PNG_NORETURN);
 
 /* The same, but the chunk name is prepended to the error string. */
 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
     png_const_charp error_message), PNG_NORETURN);
 
 #else
 /* Fatal error in PNG image of libpng - can't continue */
 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
+#  define png_error(s1,s2) png_err(s1)
+#  define png_chunk_error(s1,s2) png_err(s1)
 #endif
 
 #ifdef PNG_WARNINGS_SUPPORTED
 /* Non-fatal error in libpng.  Can continue, but may have a problem. */
 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
     png_const_charp warning_message));
 
 /* Non-fatal error in libpng, chunk name is prepended to message. */
 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
     png_const_charp warning_message));
+#else
+#  define png_warning(s1,s2) ((void)(s1))
+#  define png_chunk_warning(s1,s2) ((void)(s1))
 #endif
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 /* Benign error in libpng.  Can continue, but may have a problem.
  * User can choose whether to handle as a fatal error or as a warning. */
 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
     png_const_charp warning_message));
 
 #ifdef PNG_READ_SUPPORTED
 /* Same, chunk name is prepended to message (only during read) */
@@ skipping 97 matching lines @@
 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
     (png_const_structrp png_ptr, png_const_inforp info_ptr));
 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
     (png_const_structrp png_ptr, png_const_inforp info_ptr));
 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
     (png_const_structrp png_ptr, png_const_inforp info_ptr));
 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
     (png_const_structrp png_ptr, png_const_inforp info_ptr));
 
-#endif /* PNG_EASY_ACCESS_SUPPORTED */
+#endif /* EASY_ACCESS */
 
 #ifdef PNG_READ_SUPPORTED
 /* Returns pointer to signature string read from PNG header */
 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
     png_const_inforp info_ptr));
 #endif
 
 #ifdef PNG_bKGD_SUPPORTED
 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
     png_inforp info_ptr, png_color_16p *background));
@@ skipping 231 matching lines @@
     png_charpp swidth, png_charpp sheight));
 
 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
     png_inforp info_ptr, int unit, double width, double height))
 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
    png_inforp info_ptr, int unit, png_fixed_point width,
    png_fixed_point height))
 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
     png_inforp info_ptr, int unit,
     png_const_charp swidth, png_const_charp sheight));
-#endif /* PNG_sCAL_SUPPORTED */
+#endif /* sCAL */
 
 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 /* Provide the default handling for all unknown chunks or, optionally, for
  * specific unknown chunks.
  *
  * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
  * ignored and the default was used, the per-chunk setting only had an effect on
  * write.  If you wish to have chunk-specific handling on read in code that must
  * work on earlier versions you must use a user chunk callback to specify the
  * desired handling (keep or discard.)
@@ skipping 120 matching lines @@
 
 /* Png_free_data() will turn off the "valid" flag for anything it frees.
  * If you need to turn it off for a chunk that your application has freed,
  * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
  */
 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
     png_inforp info_ptr, int mask));
 
 #ifdef PNG_INFO_IMAGE_SUPPORTED
 /* The "params" pointer is currently not used and is for future expansion. */
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
     int transforms, png_voidp params));
+#endif
+#ifdef PNG_WRITE_SUPPORTED
 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
     int transforms, png_voidp params));
 #endif
+#endif
 
 PNG_EXPORT(180, png_const_charp, png_get_copyright,
     (png_const_structrp png_ptr));
 PNG_EXPORT(181, png_const_charp, png_get_header_ver,
     (png_const_structrp png_ptr));
 PNG_EXPORT(182, png_const_charp, png_get_header_version,
     (png_const_structrp png_ptr));
 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
     (png_const_structrp png_ptr));
 
@@ skipping 58 matching lines @@
     png_const_inforp info_ptr))
 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
     (png_const_structrp png_ptr, png_const_inforp info_ptr))
 #endif
 
 #  ifdef PNG_pHYs_SUPPORTED
 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
     png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
     int *unit_type));
-#  endif /* PNG_pHYs_SUPPORTED */
-#endif  /* PNG_INCH_CONVERSIONS_SUPPORTED */
+#  endif /* pHYs */
+#endif  /* INCH_CONVERSIONS */
 
 /* Added in libpng-1.4.0 */
 #ifdef PNG_IO_STATE_SUPPORTED
 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
 
 /* Removed from libpng 1.6; use png_get_io_chunk_type. */
 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
     PNG_DEPRECATED)
 
 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
     (png_const_structrp png_ptr));
 
 /* The flags returned by png_get_io_state() are the following: */
 #  define PNG_IO_NONE        0x0000   /* no I/O at this moment */
 #  define PNG_IO_READING     0x0001   /* currently reading */
 #  define PNG_IO_WRITING     0x0002   /* currently writing */
 #  define PNG_IO_SIGNATURE   0x0010   /* currently at the file signature */
 #  define PNG_IO_CHUNK_HDR   0x0020   /* currently at the chunk header */
 #  define PNG_IO_CHUNK_DATA  0x0040   /* currently at the chunk data */
 #  define PNG_IO_CHUNK_CRC   0x0080   /* currently at the chunk crc */
 #  define PNG_IO_MASK_OP     0x000f   /* current operation: reading/writing */
 #  define PNG_IO_MASK_LOC    0x00f0   /* current location: sig/hdr/data/crc */
-#endif /* ?PNG_IO_STATE_SUPPORTED */
+#endif /* IO_STATE */
 
 /* Interlace support.  The following macros are always defined so that if
  * libpng interlace handling is turned off the macros may be used to handle
  * interlaced images within the application.
  */
 #define PNG_INTERLACE_ADAM7_PASSES 7
 
 /* Two macros to return the first row and first column of the original,
  * full, image which appears in a given pass.  'pass' is in the range 0
  * to 6 and the result is in the range 0 to 7.
@@ skipping 63 matching lines @@
  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
  */
 
  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
 
 #  define png_composite(composite, fg, alpha, bg)         \
      { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
            * (png_uint_16)(alpha)                         \
            + (png_uint_16)(bg)*(png_uint_16)(255          \
            - (png_uint_16)(alpha)) + 128);                \
-       (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
+       (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); }
 
 #  define png_composite_16(composite, fg, alpha, bg)       \
      { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg)  \
            * (png_uint_32)(alpha)                          \
            + (png_uint_32)(bg)*(65535                      \
            - (png_uint_32)(alpha)) + 32768);               \
-       (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
+       (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); }
 
 #else  /* Standard method using integer division */
 
-#  define png_composite(composite, fg, alpha, bg)                          \
-     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +  \
-     (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
-     127) / 255)
+#  define png_composite(composite, fg, alpha, bg)                        \
+     (composite) =                                                       \
+         (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) +  \
+         (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
+         127) / 255))
 
 #  define png_composite_16(composite, fg, alpha, bg)                         \
-     (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
-     (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) +         \
-     32767) / 65535)
-#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
+     (composite) =                                                           \
+         (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
+         (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) +     \
+         32767) / 65535))
+#endif /* READ_COMPOSITE_NODIV */
 
 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
 #endif
 
 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
     png_const_bytep buf));
 /* No png_get_int_16 -- may be added if there's a real need for it. */
@@ skipping 29 matching lines @@
    /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
     * function) incorrectly returned a value of type png_uint_32.
     */
 #  define PNG_get_uint_16(buf) \
      ((png_uint_16) \
       (((unsigned int)(*(buf)) << 8) + \
        ((unsigned int)(*((buf) + 1)))))
 
 #  define PNG_get_int_32(buf) \
      ((png_int_32)((*(buf) & 0x80) \
-      ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
+      ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
       : (png_int_32)png_get_uint_32(buf)))
 
    /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
     * but defining a macro name prefixed with PNG_PREFIX.
     */
 #  ifndef PNG_PREFIX
 #     define png_get_uint_32(buf) PNG_get_uint_32(buf)
 #     define png_get_uint_16(buf) PNG_get_uint_16(buf)
 #     define png_get_int_32(buf)  PNG_get_int_32(buf)
 #  endif
 #else
 #  ifdef PNG_PREFIX
       /* No macros; revert to the (redefined) function */
 #     define PNG_get_uint_32 (png_get_uint_32)
 #     define PNG_get_uint_16 (png_get_uint_16)
 #     define PNG_get_int_32  (png_get_int_32)
 #  endif
 #endif
 
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+PNG_EXPORT(242, void, png_set_check_for_invalid_index,
+    (png_structrp png_ptr, int allowed));
+#  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+#  endif
+#endif /* CHECK_FOR_INVALID_INDEX */
+
 /*******************************************************************************
- *  SIMPLIFIED API
+ * Section 5: SIMPLIFIED API
  *******************************************************************************
  *
  * Please read the documentation in libpng-manual.txt (TODO: write said
  * documentation) if you don't understand what follows.
  *
  * The simplified API hides the details of both libpng and the PNG file format
  * itself.  It allows PNG files to be read into a very limited number of
  * in-memory bitmap formats or to be written from the same formats.  If these
  * formats do not accomodate your needs then you can, and should, use the more
  * sophisticated APIs above - these support a wide variety of in-memory formats
  * and a wide variety of sophisticated transformations to those formats as well
  * as a wide variety of APIs to manipulate ancillary information.
  *
  * To read a PNG file using the simplified API:
  *
- * 1) Declare a 'png_image' structure (see below) on the stack and set the
- *    version field to PNG_IMAGE_VERSION.
+ * 1) Declare a 'png_image' structure (see below) on the stack, set the
+ *    version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
+ *    (this is REQUIRED, your program may crash if you don't do it.)
  * 2) Call the appropriate png_image_begin_read... function.
  * 3) Set the png_image 'format' member to the required sample format.
  * 4) Allocate a buffer for the image and, if required, the color-map.
  * 5) Call png_image_finish_read to read the image and, if required, the
  *    color-map into your buffers.
  *
  * There are no restrictions on the format of the PNG input itself; all valid
  * color types, bit depths, and interlace methods are acceptable, and the
  * input image is transformed as necessary to the requested in-memory format
  * during the png_image_finish_read() step.  The only caveat is that if you
  * request a color-mapped image from a PNG that is full-color or makes
  * complex use of an alpha channel the transformation is extremely lossy and the
  * result may look terrible.
  *
  * To write a PNG file using the simplified API:
  *
  * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
  * 2) Initialize the members of the structure that describe the image, setting
  *    the 'format' member to the format of the image samples.
  * 3) Call the appropriate png_image_write... function with a pointer to the
  *    image and, if necessary, the color-map to write the PNG data.
  *
  * png_image is a structure that describes the in-memory format of an image
  * when it is being read or defines the in-memory format of an image that you
  * need to write:
  */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
+    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+
 #define PNG_IMAGE_VERSION 1
 
 typedef struct png_control *png_controlp;
 typedef struct
 {
    png_controlp opaque;    /* Initialize to NULL, free with png_image_free */
    png_uint_32  version;   /* Set to PNG_IMAGE_VERSION */
    png_uint_32  width;     /* Image width in pixels (columns) */
    png_uint_32  height;    /* Image height in pixels (rows) */
    png_uint_32  format;    /* Image format as defined below */
    png_uint_32  flags;     /* A bit mask containing informational flags */
    png_uint_32  colormap_entries;
                            /* Number of entries in the color-map */
 
    /* In the event of an error or warning the following field will be set to a
     * non-zero value and the 'message' field will contain a '\0' terminated
     * string with the libpng error or warning message.  If both warnings and
     * an error were encountered, only the error is recorded.  If there
     * are multiple warnings, only the first one is recorded.
     *
     * The upper 30 bits of this value are reserved, the low two bits contain
     * a value as follows:
     */
 #  define PNG_IMAGE_WARNING 1
 #  define PNG_IMAGE_ERROR 2
    /*
-    * The result is a two bit code such that a value more than 1 indicates
+    * The result is a two-bit code such that a value more than 1 indicates
     * a failure in the API just called:
     *
     *    0 - no warning or error
     *    1 - warning
     *    2 - error
     *    3 - error preceded by warning
     */
 #  define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
 
    png_uint_32  warning_or_error;
@@ skipping 52 matching lines @@
  * valid.  Formats can be built up from the flag values or you can use one of
  * the predefined values below.  When testing formats always use the FORMAT_FLAG
  * macros to test for individual features - future versions of the library may
  * add new flags.
  *
  * When reading or writing color-mapped images the format should be set to the
  * format of the entries in the color-map then png_image_{read,write}_colormap
  * called to read or write the color-map and set the format correctly for the
  * image data.  Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
  *
- * NOTE: libpng can be built with particular features disabled, if you see
+ * NOTE: libpng can be built with particular features disabled. If you see
  * compiler errors because the definition of one of the following flags has been
  * compiled out it is because libpng does not have the required support.  It is
  * possible, however, for the libpng configuration to enable the format on just
  * read or just write; in that case you may see an error at run time.  You can
  * guard against this by checking for the definition of the appropriate
  * "_SUPPORTED" macro, one of:
  *
  *    PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
  */
 #define PNG_FORMAT_FLAG_ALPHA    0x01U /* format with an alpha channel */
 #define PNG_FORMAT_FLAG_COLOR    0x02U /* color format: otherwise grayscale */
-#define PNG_FORMAT_FLAG_LINEAR   0x04U /* 2 byte channels else 1 byte */
+#define PNG_FORMAT_FLAG_LINEAR   0x04U /* 2-byte channels else 1-byte */
 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
 
 #ifdef PNG_FORMAT_BGR_SUPPORTED
 #  define PNG_FORMAT_FLAG_BGR    0x10U /* BGR colors, else order is RGB */
 #endif
 
 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
 #  define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
 #endif
 
@@ skipping 179 matching lines @@
 #ifdef PNG_STDIO_SUPPORTED
 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
    const char *file_name));
    /* The named file is opened for read and the image header is filled in
     * from the PNG header in the file.
     */
 
 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
    FILE* file));
    /* The PNG header is read from the stdio FILE object. */
-#endif /* PNG_STDIO_SUPPORTED */
+#endif /* STDIO */
 
 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
    png_const_voidp memory, png_size_t size));
    /* The PNG header is read from the given memory buffer. */
 
 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
    png_const_colorp background, void *buffer, png_int_32 row_stride,
    void *colormap));
    /* Finish reading the image into the supplied buffer and clean up the
     * png_image structure.
@@ skipping 24 matching lines @@
     * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set.  It must
     * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
     * image->colormap_entries will be updated to the actual number of entries
     * written to the colormap; this may be less than the original value.
     */
 
 PNG_EXPORT(238, void, png_image_free, (png_imagep image));
    /* Free any data allocated by libpng in image->opaque, setting the pointer to
     * NULL.  May be called at any time after the structure is initialized.
     */
-#endif /* PNG_SIMPLIFIED_READ_SUPPORTED */
+#endif /* SIMPLIFIED_READ */
 
 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
 #ifdef PNG_STDIO_SUPPORTED
 /* WRITE APIS
  * ----------
  * For write you must initialize a png_image structure to describe the image to
  * be written.  To do this use memset to set the whole structure to 0 then
  * initialize fields describing your image.
  *
  * version: must be set to PNG_IMAGE_VERSION
@@ skipping 21 matching lines @@
  * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
  * encoded PNG file is written.
  *
  * With color-mapped data formats the colormap parameter point to a color-map
  * with at least image->colormap_entries encoded in the specified format.  If
  * the format is linear the written PNG color-map will be converted to sRGB
  * regardless of the convert_to_8_bit flag.
  *
  * With all APIs row_stride is handled as in the read APIs - it is the spacing
  * from one row to the next in component sized units (1 or 2 bytes) and if
- * negative indicates a bottom-up row layout in the buffer.
+ * negative indicates a bottom-up row layout in the buffer.  If row_stride is zero,
+ * libpng will calculate it for you from the image width and number of channels.
  *
- * Note that the write API does not support interlacing or sub-8-bit pixels.
+ * Note that the write API does not support interlacing, sub-8-bit pixels, indexed
+ * PNG (color_type 3) or most ancillary chunks.
  */
-#endif /* PNG_STDIO_SUPPORTED */
-#endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */
+#endif /* STDIO */
+#endif /* SIMPLIFIED_WRITE */
 /*******************************************************************************
  *  END OF SIMPLIFIED API
  ******************************************************************************/
-
-#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-PNG_EXPORT(242, void, png_set_check_for_invalid_index,
-    (png_structrp png_ptr, int allowed));
-#  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
-PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
-    png_const_infop info_ptr));
-#  endif
-#endif /* CHECK_FOR_INVALID_INDEX */
+#endif /* SIMPLIFIED_{READ|WRITE} */
 
 /*******************************************************************************
- *  IMPLEMENTATION OPTIONS
+ * Section 6: IMPLEMENTATION OPTIONS
  *******************************************************************************
  *
  * Support for arbitrary implementation-specific optimizations.  The API allows
  * particular options to be turned on or off.  'Option' is the number of the
  * option and 'onoff' is 0 (off) or non-0 (on).  The value returned is given
  * by the PNG_OPTION_ defines below.
  *
  * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
  *           are detected at run time, however sometimes it may be impossible
  *           to do this in user mode, in which case it is necessary to discover
  *           the capabilities in an OS specific way.  Such capabilities are
  *           listed here when libpng has support for them and must be turned
  *           ON by the application if present.
  *
  * SOFTWARE: sometimes software optimizations actually result in performance
  *           decrease on some architectures or systems, or with some sets of
  *           PNG images.  'Software' options allow such optimizations to be
  *           selected at run time.
  */
 #ifdef PNG_SET_OPTION_SUPPORTED
 #ifdef PNG_ARM_NEON_API_SUPPORTED
 #  define PNG_ARM_NEON   0 /* HARDWARE: ARM Neon SIMD instructions supported */
 #endif
 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
-#define PNG_OPTION_NEXT  4 /* Next option - numbers must be even */
+#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
+#define PNG_OPTION_NEXT  6 /* Next option - numbers must be even */
 
 /* Return values: NOTE: there are four values and 'off' is *not* zero */
 #define PNG_OPTION_UNSET   0 /* Unset - defaults to off */
 #define PNG_OPTION_INVALID 1 /* Option number out of range */
 #define PNG_OPTION_OFF     2
 #define PNG_OPTION_ON      3
 
 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
    int onoff));
-#endif
+#endif /* SET_OPTION */
 
 /*******************************************************************************
- *  END OF HARDWARE OPTIONS
+ *  END OF HARDWARE AND SOFTWARE OPTIONS
  ******************************************************************************/
 
-/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
- * defs, scripts/pnglibconf.h, and scripts/pnglibconf.h.prebuilt
+/* Maintainer: Put new public prototypes here ^, in libpng.3, in project
+ * defs, and in scripts/symbols.def.
  */
 
 /* The last ordinal number (this is the *last* one already used; the next
- * one to use is one more than this.)  Maintainer, remember to add an entry to
- * scripts/symbols.def as well.
+ * one to use is one more than this.)
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
   PNG_EXPORT_LAST_ORDINAL(244);
 #endif
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* PNG_VERSION_INFO_ONLY */
 /* Do not put anything past this line */
 #endif /* PNG_H */