third_party/libpng: update to 1.2.54

third_party/libpng/png.h

+
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.2.52 - November 20, 2014
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * libpng version 1.2.54, November 12, 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 1.2.52 - November 20, 2014: Glenn
+ *  libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
+ *  libpng versions 0.97, January 1998, through 1.2.54, November 12, 2015: Glenn
  *  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  10.so.0.1.0.17rc1
- *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
- *    1.0.17                  10    10017  10.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  10.so.0.1.0.18rc1-5
- *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
- *    1.0.18                  10    10018  10.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]
- *    1.2.10beta1-8           13    10210  12.so.0.10[.0]
- *    1.2.10rc1-3             13    10210  12.so.0.10[.0]
- *    1.2.10                  13    10210  12.so.0.10[.0]
- *    1.2.11beta1-4           13    10211  12.so.0.11[.0]
- *    1.0.19rc1-5             10    10019  10.so.0.19[.0]
- *    1.2.11rc1-5             13    10211  12.so.0.11[.0]
- *    1.0.19                  10    10019  10.so.0.19[.0]
- *    1.2.11                  13    10211  12.so.0.11[.0]
- *    1.0.20                  10    10020  10.so.0.20[.0]
- *    1.2.12                  13    10212  12.so.0.12[.0]
- *    1.2.13beta1             13    10213  12.so.0.13[.0]
- *    1.0.21                  10    10021  10.so.0.21[.0]
- *    1.2.13                  13    10213  12.so.0.13[.0]
- *    1.2.14beta1-2           13    10214  12.so.0.14[.0]
- *    1.0.22rc1               10    10022  10.so.0.22[.0]
- *    1.2.14rc1               13    10214  12.so.0.14[.0]
- *    1.0.22                  10    10022  10.so.0.22[.0]
- *    1.2.14                  13    10214  12.so.0.14[.0]
- *    1.2.15beta1-6           13    10215  12.so.0.15[.0]
- *    1.0.23rc1-5             10    10023  10.so.0.23[.0]
- *    1.2.15rc1-5             13    10215  12.so.0.15[.0]
- *    1.0.23                  10    10023  10.so.0.23[.0]
- *    1.2.15                  13    10215  12.so.0.15[.0]
- *    1.2.16beta1-2           13    10216  12.so.0.16[.0]
- *    1.2.16rc1               13    10216  12.so.0.16[.0]
- *    1.0.24                  10    10024  10.so.0.24[.0]
- *    1.2.16                  13    10216  12.so.0.16[.0]
- *    1.2.17beta1-2           13    10217  12.so.0.17[.0]
- *    1.0.25rc1               10    10025  10.so.0.25[.0]
- *    1.2.17rc1-3             13    10217  12.so.0.17[.0]
- *    1.0.25                  10    10025  10.so.0.25[.0]
- *    1.2.17                  13    10217  12.so.0.17[.0]
- *    1.0.26                  10    10026  10.so.0.26[.0]
- *    1.2.18                  13    10218  12.so.0.18[.0]
- *    1.2.19beta1-31          13    10219  12.so.0.19[.0]
- *    1.0.27rc1-6             10    10027  10.so.0.27[.0]
- *    1.2.19rc1-6             13    10219  12.so.0.19[.0]
- *    1.0.27                  10    10027  10.so.0.27[.0]
- *    1.2.19                  13    10219  12.so.0.19[.0]
- *    1.2.20beta01-04         13    10220  12.so.0.20[.0]
- *    1.0.28rc1-6             10    10028  10.so.0.28[.0]
- *    1.2.20rc1-6             13    10220  12.so.0.20[.0]
- *    1.0.28                  10    10028  10.so.0.28[.0]
- *    1.2.20                  13    10220  12.so.0.20[.0]
- *    1.2.21beta1-2           13    10221  12.so.0.21[.0]
- *    1.2.21rc1-3             13    10221  12.so.0.21[.0]
- *    1.0.29                  10    10029  10.so.0.29[.0]
- *    1.2.21                  13    10221  12.so.0.21[.0]
- *    1.2.22beta1-4           13    10222  12.so.0.22[.0]
- *    1.0.30rc1               10    10030  10.so.0.30[.0]
- *    1.2.22rc1               13    10222  12.so.0.22[.0]
- *    1.0.30                  10    10030  10.so.0.30[.0]
- *    1.2.22                  13    10222  12.so.0.22[.0]
- *    1.2.23beta01-05         13    10223  12.so.0.23[.0]
- *    1.2.23rc01              13    10223  12.so.0.23[.0]
- *    1.2.23                  13    10223  12.so.0.23[.0]
- *    1.2.24beta01-02         13    10224  12.so.0.24[.0]
- *    1.2.24rc01              13    10224  12.so.0.24[.0]
- *    1.2.24                  13    10224  12.so.0.24[.0]
- *    1.2.25beta01-06         13    10225  12.so.0.25[.0]
- *    1.2.25rc01-02           13    10225  12.so.0.25[.0]
- *    1.0.31                  10    10031  10.so.0.31[.0]
- *    1.2.25                  13    10225  12.so.0.25[.0]
- *    1.2.26beta01-06         13    10226  12.so.0.26[.0]
- *    1.2.26rc01              13    10226  12.so.0.26[.0]
- *    1.2.26                  13    10226  12.so.0.26[.0]
- *    1.0.32                  10    10032  10.so.0.32[.0]
- *    1.2.27beta01-06         13    10227  12.so.0.27[.0]
- *    1.2.27rc01              13    10227  12.so.0.27[.0]
- *    1.0.33                  10    10033  10.so.0.33[.0]
- *    1.2.27                  13    10227  12.so.0.27[.0]
- *    1.0.34                  10    10034  10.so.0.34[.0]
- *    1.2.28                  13    10228  12.so.0.28[.0]
- *    1.2.29beta01-03         13    10229  12.so.0.29[.0]
- *    1.2.29rc01              13    10229  12.so.0.29[.0]
- *    1.0.35                  10    10035  10.so.0.35[.0]
- *    1.2.29                  13    10229  12.so.0.29[.0]
- *    1.0.37                  10    10037  10.so.0.37[.0]
- *    1.2.30beta01-04         13    10230  12.so.0.30[.0]
- *    1.0.38rc01-08           10    10038  10.so.0.38[.0]
- *    1.2.30rc01-08           13    10230  12.so.0.30[.0]
- *    1.0.38                  10    10038  10.so.0.38[.0]
- *    1.2.30                  13    10230  12.so.0.30[.0]
- *    1.0.39rc01-03           10    10039  10.so.0.39[.0]
- *    1.2.31rc01-03           13    10231  12.so.0.31[.0]
- *    1.0.39                  10    10039  10.so.0.39[.0]
- *    1.2.31                  13    10231  12.so.0.31[.0]
- *    1.2.32beta01-02         13    10232  12.so.0.32[.0]
- *    1.0.40rc01              10    10040  10.so.0.40[.0]
- *    1.2.32rc01              13    10232  12.so.0.32[.0]
- *    1.0.40                  10    10040  10.so.0.40[.0]
- *    1.2.32                  13    10232  12.so.0.32[.0]
- *    1.2.33beta01-02         13    10233  12.so.0.33[.0]
- *    1.2.33rc01-02           13    10233  12.so.0.33[.0]
- *    1.0.41rc01              10    10041  10.so.0.41[.0]
- *    1.2.33                  13    10233  12.so.0.33[.0]
- *    1.0.41                  10    10041  10.so.0.41[.0]
- *    1.2.34beta01-07         13    10234  12.so.0.34[.0]
- *    1.0.42rc01              10    10042  10.so.0.42[.0]
- *    1.2.34rc01              13    10234  12.so.0.34[.0]
- *    1.0.42                  10    10042  10.so.0.42[.0]
- *    1.2.34                  13    10234  12.so.0.34[.0]
- *    1.2.35beta01-03         13    10235  12.so.0.35[.0]
- *    1.0.43rc01-02           10    10043  10.so.0.43[.0]
- *    1.2.35rc01-02           13    10235  12.so.0.35[.0]
- *    1.0.43                  10    10043  10.so.0.43[.0]
- *    1.2.35                  13    10235  12.so.0.35[.0]
- *    1.2.36beta01-05         13    10236  12.so.0.36[.0]
- *    1.2.36rc01              13    10236  12.so.0.36[.0]
- *    1.0.44                  10    10044  10.so.0.44[.0]
- *    1.2.36                  13    10236  12.so.0.36[.0]
- *    1.2.37beta01-03         13    10237  12.so.0.37[.0]
- *    1.2.37rc01              13    10237  12.so.0.37[.0]
- *    1.2.37                  13    10237  12.so.0.37[.0]
- *    1.0.45                  10    10045  12.so.0.45[.0]
- *    1.0.46                  10    10046  10.so.0.46[.0]
- *    1.2.38beta01            13    10238  12.so.0.38[.0]
- *    1.2.38rc01-03           13    10238  12.so.0.38[.0]
- *    1.0.47                  10    10047  10.so.0.47[.0]
- *    1.2.38                  13    10238  12.so.0.38[.0]
- *    1.2.39beta01-05         13    10239  12.so.0.39[.0]
- *    1.2.39rc01              13    10239  12.so.0.39[.0]
- *    1.0.48                  10    10048  10.so.0.48[.0]
- *    1.2.39                  13    10239  12.so.0.39[.0]
- *    1.2.40beta01            13    10240  12.so.0.40[.0]
- *    1.2.40rc01              13    10240  12.so.0.40[.0]
- *    1.0.49                  10    10049  10.so.0.49[.0]
- *    1.2.40                  13    10240  12.so.0.40[.0]
- *    1.2.41beta01-18         13    10241  12.so.0.41[.0]
- *    1.0.51rc01              10    10051  10.so.0.51[.0]
- *    1.2.41rc01-03           13    10241  12.so.0.41[.0]
- *    1.0.51                  10    10051  10.so.0.51[.0]
- *    1.2.41                  13    10241  12.so.0.41[.0]
- *    1.2.42beta01-02         13    10242  12.so.0.42[.0]
- *    1.2.42rc01-05           13    10242  12.so.0.42[.0]
- *    1.0.52                  10    10052  10.so.0.52[.0]
- *    1.2.42                  13    10242  12.so.0.42[.0]
- *    1.2.43beta01-05         13    10243  12.so.0.43[.0]
- *    1.0.53rc01-02           10    10053  10.so.0.53[.0]
- *    1.2.43rc01-02           13    10243  12.so.0.43[.0]
- *    1.0.53                  10    10053  10.so.0.53[.0]
- *    1.2.43                  13    10243  12.so.0.43[.0]
- *    1.2.44beta01-03         13    10244  12.so.0.44[.0]
- *    1.2.44rc01-03           13    10244  12.so.0.44[.0]
- *    1.2.44                  13    10244  12.so.0.44[.0]
- *    1.2.45beta01-03         13    10245  12.so.0.45[.0]
- *    1.0.55rc01              10    10055  10.so.0.55[.0]
- *    1.2.45rc01              13    10245  12.so.0.45[.0]
- *    1.0.55                  10    10055  10.so.0.55[.0]
- *    1.2.45                  13    10245  12.so.0.45[.0]
- *    1.2.46rc01-02           13    10246  12.so.0.46[.0]
- *    1.0.56                  10    10056  10.so.0.56[.0]
- *    1.2.46                  13    10246  12.so.0.46[.0]
- *    1.2.47beta01            13    10247  12.so.0.47[.0]
- *    1.2.47rc01              13    10247  12.so.0.47[.0]
- *    1.0.57rc01              10    10057  10.so.0.57[.0]
- *    1.2.47                  13    10247  12.so.0.47[.0]
- *    1.0.57                  10    10057  10.so.0.57[.0]
- *    1.2.48beta01            13    10248  12.so.0.48[.0]
- *    1.2.48rc01-02           13    10248  12.so.0.48[.0]
- *    1.0.58                  10    10058  10.so.0.58[.0]
- *    1.2.48                  13    10248  12.so.0.48[.0]
- *    1.2.49rc01              13    10249  12.so.0.49[.0]
- *    1.0.59                  10    10059  10.so.0.59[.0]
- *    1.2.49                  13    10249  12.so.0.49[.0]
- *    1.0.60                  10    10060  10.so.0.60[.0]
- *    1.2.50                  13    10250  12.so.0.50[.0]
- *    1.2.51beta01-05         13    10251  12.so.0.51[.0]
- *    1.2.51rc01-04           13    10251  12.so.0.51[.0]
- *    1.0.61                  10    10061  10.so.0.61[.0]
- *    1.2.51                  13    10251  12.so.0.51[.0]
- *    1.2.52beta01            13    10252  12.so.0.52[.0]
- *    1.2.52rc01-02           13    10252  12.so.0.52[.0]
- *    1.0.62                  10    10062  10.so.0.62[.0]
- *    1.2.52                  13    10252  12.so.0.52[.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/
  */
 
 /*
  * 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 1.2.52, November 20, 2014, 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 1.2.54, November 12, 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
+ *    Cosmin Truta
  *    Gilles Vollant
  *
  * 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.
+ *   1. The origin of this source code must not be misrepresented.
  *
- * 2. Altered versions must be plainly marked as such and
- * must not be misrepresented as being the original source.
+ *   2. Altered versions must be plainly marked as such and must not
+ *      be misrepresented as being the original source.
  *
- * 3. This Copyright notice may not be removed or altered from
- *    any source or altered source distribution.
+ *   3. This Copyright notice may not be removed or altered from any
+ *      source or altered source distribution.
  *
  * The Contributing Authors and Group 42, Inc. specifically permit, without
  * fee, and encourage the use of this source code as a component to
  * 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]
+ *    ...
+ *    1.0.64                  10    10064  10.so.0.64[.0]
+ *    1.2.54                  13    10254  12.so.0.54[.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:
  * =========================
  *
- *    November 20, 2014
+ *    November 12, 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 1.2.52 are Y2K compliant.  It is my belief that earlier
+ *    upward through 1.2.54 are Y2K compliant.  It is my belief that earlier
  *    versions were also Y2K compliant.
  *
  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
  *    that will hold years up to 65535.  The other two hold the date in text
  *    format, and will hold years up to 9999.
  *
  *    The integer is
  *        "png_uint_16 year" in png_time_struct.
  *
  *    The strings are
@@ skipping 35 matching lines @@
 #ifndef PNG_H
 #define PNG_H
 
 /* This is not the place to learn how to use libpng.  The file libpng.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.
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.2.52"
+#define PNG_LIBPNG_VER_STRING "1.2.54"
 #define PNG_HEADER_VERSION_STRING \
-   " libpng version 1.2.52 - November 20, 2014\n"
+   " libpng version 1.2.54 - November 12, 2015\n"
 
 #define PNG_LIBPNG_VER_SONUM   0
 #define PNG_LIBPNG_VER_DLLNUM  13
 
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   2
-#define PNG_LIBPNG_VER_RELEASE 52
+#define PNG_LIBPNG_VER_RELEASE 54
 /* 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
 #define PNG_LIBPNG_BUILD_RC       3
 #define PNG_LIBPNG_BUILD_STABLE   4
 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
 
 /* Release-Specific Flags */
 #define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
                                        PNG_LIBPNG_BUILD_STABLE only */
 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
                                        PNG_LIBPNG_BUILD_SPECIAL */
 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
                                        PNG_LIBPNG_BUILD_PRIVATE */
 
 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
 
 /* 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 10252 /* 1.2.52 */
+#define PNG_LIBPNG_VER 10254 /* 1.2.54 */
 
 #ifndef PNG_VERSION_INFO_ONLY
 /* Include the compression library's header */
 #include "zlib.h"
 #endif
 
 /* Include all user configurable info, including optional assembler routines */
 #include "pngconf.h"
 
 /*
@@ skipping 895 matching lines @@
 
 #ifdef PNG_READ_DITHER_SUPPORTED
    png_bytep palette_lookup PNG_DEPSTRUCT;         /* lookup table for dithering */
    png_bytep dither_index PNG_DEPSTRUCT;           /* index translation for palette files */
 #endif
 
 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
    png_uint_16p hist PNG_DEPSTRUCT;                /* histogram */
 #endif
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-   png_byte heuristic_method PNG_DEPSTRUCT;        /* heuristic for row filter selection */
-   png_byte num_prev_filters PNG_DEPSTRUCT;        /* number of weights for previous rows */
-   png_bytep prev_filters PNG_DEPSTRUCT;           /* filter type(s) of previous row(s) */
-   png_uint_16p filter_weights PNG_DEPSTRUCT;      /* weight(s) for previous line(s) */
-   png_uint_16p inv_filter_weights PNG_DEPSTRUCT;  /* 1/weight(s) for previous line(s) */
-   png_uint_16p filter_costs PNG_DEPSTRUCT;        /* relative filter calculation cost */
-   png_uint_16p inv_filter_costs PNG_DEPSTRUCT;    /* 1/relative filter calculation cost */
-#endif
-
 #ifdef PNG_TIME_RFC1123_SUPPORTED
    png_charp time_buffer PNG_DEPSTRUCT;            /* String to hold RFC 1123 time text */
 #endif
 
 /* New members added in libpng-1.0.6 */
 
 #ifdef PNG_FREE_ME_SUPPORTED
    png_uint_32 free_me PNG_DEPSTRUCT;   /* flags items libpng is responsible for freeing */
 #endif
 
@@ skipping 94 matching lines @@
 /* New member added in libpng-1.2.30 */
   png_charp chunkdata PNG_DEPSTRUCT;  /* buffer for reading chunk data */
 
 
 };
 
 
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef png_structp version_1_2_52;
+typedef png_structp version_1_2_54;
 
 typedef png_struct FAR * FAR * png_structpp;
 
 /* Here are the function definitions most commonly used.  This is not
  * the place to find out how to use libpng.  See libpng.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.
  */
 
 /* Returns the version number of the library */
@@ skipping 380 matching lines @@
 /* 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
 
-#if defined(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.
- */
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* DEPRECATED */
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
    int heuristic_method, int num_weights, png_doublep filter_weights,
    png_doublep filter_costs));
 #endif
 #endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
 
-/* 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 */
 
 /* 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,
@@ skipping 1779 matching lines @@
 
 #endif /* PNG_INTERNAL */
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* PNG_VERSION_INFO_ONLY */
 /* Do not put anything past this line */
 #endif /* PNG_H */