[libpng17] Imported from libpng-1.7.0beta53.tar

pointer usage.

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.7.0beta47 - January 27, 2015
+Libpng 1.7.0beta53 - February 23, 2015
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -9,20 +9,20 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.7.0beta47.tar.xz (LZMA-compressed, recommended)
-   1.7.0beta47.tar.gz
+   1.7.0beta53.tar.xz (LZMA-compressed, recommended)
+   1.7.0beta53.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp170b47.7z  (LZMA-compressed, recommended)
-   lp170b47.zip
+   lp170b53.7z  (LZMA-compressed, recommended)
+   lp170b53.zip
 
 Other information:
 
-   1.7.0beta47-README.txt
-   1.7.0beta47-LICENSE.txt
-   libpng-1.7.0beta47-*.asc (armored detached GPG signatures)
+   1.7.0beta53-README.txt
+   1.7.0beta53-LICENSE.txt
+   libpng-1.7.0beta53-*.asc (armored detached GPG signatures)
 
 Changes since the last public release (1.6.0):
 
@@ -688,7 +688,7 @@ Version 1.7.0beta46 [January 2, 2015]
   Fixed byte order in 2-byte filler, in png_do_read_filler().
   Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
 
-Version 1.7.0beta47 [January 27, 2015]
+Version 1.7.0beta47 [January 29, 2015]
   Made the check for out-of-range values in png_set_tRNS() detect
     values that are exactly 2^bit_depth, and work on 16-bit platforms.
   Added PNG_SKIP_sRGB_CHECK_PROFILE choice for png_set_option().
@@ -697,6 +697,40 @@ Version 1.7.0beta47 [January 27, 2015]
   Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and
     pngset.c to avoid warnings about dead code.
 
+Version 1.7.0beta48 [February 7, 2015]
+  Work around one more Coverity-scan dead-code warning.
+  Do not build png_product2() when it is unused.
+
+Version 1.7.0beta49 [February 11, 2015]
+  Combined sub_row, up_row, avg_row, and paeth_row buffers into a
+    single try_row buffer.
+  Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
+  Consolidated redundant code in pngwutil.c
+  Deal with integer overflow of sum in pngwutil.c
+
+Version 1.7.0beta50 [February 15, 2015]
+  Combined sub_row, up_row, avg_row, and paeth_row buffers into a
+    single try_row buffer and in cases where two or more of those are
+    being tested, a second tst_row buffer.  This improves CPU speed
+    over that achieved by libpng-1.7.0beta49.
+
+Version 1.7.0beta51 [February 17, 2015]
+  Combined similar parts of png_write_find_filter() into a png_increase_lmins()
+    function.
+  Display user limits in the output from pngtest.
+  Replaced test for harmless integer overflow (wraparound) in pngwutil.c
+    with a method that prevents overflow and does not increase cpu usage
+    significantly.
+
+Version 1.7.0beta52 [February 21, 2015]
+  Added information about setjmp/simplified API interaction in the
+    manual page and INSTALL file. Added information about using
+    row_pointers with a single height*width*bpp allocated block
+  Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
+
+Version 1.7.0beta53 [February 23, 2015]
+  Restored compiling of png_reciprocal2 with PNG_NO_16BIT.
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CHANGES

@@ -4977,7 +4977,7 @@ Version 1.7.0beta46 [January 2, 2015]
   Fixed byte order in 2-byte filler, in png_do_read_filler().
   Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
 
-Version 1.7.0beta47 [January 27, 2015]
+Version 1.7.0beta47 [January 29, 2015]
   Made the check for out-of-range values in png_set_tRNS() detect
     values that are exactly 2^bit_depth, and work on 16-bit platforms.
   Added PNG_SKIP_sRGB_CHECK_PROFILE choice for png_set_option().
@@ -4986,6 +4986,41 @@ Version 1.7.0beta47 [January 27, 2015]
   Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and
     pngset.c to avoid warnings about dead code.
 
+Version 1.7.0beta48 [February 7, 2015]
+  Work around one more Coverity-scan dead-code warning.
+  Do not build png_product2() when it is unused.
+
+Version 1.7.0beta49 [February 11, 2015]
+  Combined sub_row, up_row, avg_row, and paeth_row buffers into a
+    single try_row buffer.
+  Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
+  Consolidated redundant code in pngwutil.c
+  Deal with integer overflow of sum in pngwutil.c
+
+Version 1.7.0beta50 [February 15, 2015]
+  Combined sub_row, up_row, avg_row, and paeth_row buffers into a
+    single try_row buffer and in cases where two or more of those are
+    being tested, a second tst_row buffer.  This improves CPU speed
+    over that achieved by libpng-1.7.0beta49.
+
+Version 1.7.0beta51 [February 17, 2015]
+  Combined similar parts of png_write_find_filter() into a png_increase_lmins()
+    function.
+  Display user limits in the output from pngtest.
+  Replaced test for harmless integer overflow (wraparound) in pngwutil.c
+    with a method that prevents overflow and does not increase cpu usage
+    significantly.
+
+Version 1.7.0beta52 [February 21, 2015]
+  Added information about setjmp/simplified API interaction in the
+    manual page and INSTALL file. Added information about using
+    row_pointers with a single height*width*bpp allocated block
+    to the manual page.
+  Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
+
+Version 1.7.0beta53 [February 23, 2015]
+  Restored compiling of png_reciprocal2 with PNG_NO_16BIT.
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CMakeLists.txt

@@ -253,7 +253,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 17.${PNGLIB_RELEASE}.1.7.0beta47
+#   VERSION 17.${PNGLIB_RELEASE}.1.7.0beta53
     VERSION 17.${PNGLIB_RELEASE}.0
     SOVERSION 17
     CLEAN_DIRECT_OUTPUT 1)

INSTALL

@@ -17,7 +17,7 @@ VIII. Configuring libpng for 16-bit platforms
  XII. Configuring for compiler xxx:
 XIII. Removing unwanted object code
  XIV. Changes to the build and configuration of libpng in libpng-1.5.x
-  XV. Configuring libpng for multiprocessing
+  XV. Setjmp/longjmp issues
  XVI. Other sources of information about libpng
 
 I. Simple installation
@@ -362,7 +362,7 @@ $PREFIX/include directory).  Do not edit pnglibconf.h after you have built
 libpng, because than the settings would not accurately reflect the settings
 that were used to build libpng.
 
-XV. Configuring libpng for multiprocessing
+XV. Setjmp/longjmp issues
 
 Libpng uses setjmp()/longjmp() for error handling.  Unfortunately setjmp()
 is known to be not thread-safe on some platforms and we don't know of
@@ -375,6 +375,11 @@ configure libpng with PNG_NO_SETJMP in your pngusr.dfa file, with
 
 in your pnglibconf.h or pngusr.h.
 
+Starting with libpng-1.6.0, the library included a "simplified API".
+This requires setjmp/longjmp, so you must either build the library
+with PNG_SETJMP_SUPPORTED defined, or with PNG_SIMPLIFIED_READ_SUPPORTED
+and PNG_SIMPLIFIED_WRITE_SUPPORTED undefined.
+
 XVI. Other sources of information about libpng:
 
 Further information can be found in the README and libpng-manual.txt

LICENSE

@@ -10,8 +10,8 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.7.0beta47, January 27, 2015, are
-Copyright (c) 2004, 2006-2014 Glenn Randers-Pehrson, and are
+libpng versions 1.2.6, August 15, 2004, through 1.7.0beta53, February 23, 2015, are
+Copyright (c) 2004, 2006-2015 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
 
@@ -108,4 +108,4 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-January 27, 2015
+February 23, 2015

README

@@ -1,4 +1,4 @@
-README for libpng version 1.7.0beta47 - January 27, 2015 (shared library 17.0)
+README for libpng version 1.7.0beta53 - February 23, 2015 (shared library 17.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.

configure.ac

@@ -18,7 +18,7 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.7.0beta47],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.7.0beta53],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -39,7 +39,7 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
 
-PNGLIB_VERSION=1.7.0beta47
+PNGLIB_VERSION=1.7.0beta53
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=7
 PNGLIB_RELEASE=0

libpng-manual.txt

@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.7.0beta47 - January 27, 2015
+ libpng version 1.7.0beta53 - February 23, 2015
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.7.0beta47 - January 27, 2015
+ libpng versions 0.97, January 1998, through 1.7.0beta53 - February 23, 2015
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
@@ -434,6 +434,10 @@ You can #define PNG_ABORT to a function or other C code that does something
 more useful than abort(), as long as your function does not
 return.
 
+If you do this, you cannot #define PNG_SIMPLIFIED_READ_SUPPORTED or
+PNG_SIMPLIFIED_WRITE_SUPPORTED, because the simplified API requires
+setjmp() support.
+
 Now you need to set up the input code.  The default for libpng is to
 use the C function fread().  If you use this, you will need to pass a
 valid FILE * in the function png_init_io().  Be sure that the file is
@@ -1181,7 +1185,10 @@ row_pointers prior to calling png_read_png() with
    png_set_rows(png_ptr, info_ptr, &row_pointers);
 
 Alternatively you could allocate your image in one big block and define
-row_pointers[i] to point into the proper places in your block.
+row_pointers[i] to point into the proper places in your block.  If
+you do this, be sure to call png_read_update_info() described below,
+to update the "rowbytes" value to account for any transformations that
+change the number of bytes per row before you use it to allocate your block.
 
 If you use png_set_rows(), the application is responsible for freeing
 row_pointers (and row_pointers[i], if they were separately allocated).
@@ -1266,13 +1273,13 @@ in until png_read_end() has read the chunk data following the image.
                      the PNG datastream is embedded in
                      a MNG-1.0 datastream)
 
-    Any or all of color_tye, bit_depth, interlace_type,
-    compression_type, or filter_method can be NULL if you
-    are not interested in their values.
+    Any of width, height, color_type, bit_depth,
+    interlace_type, compression_type, or filter_method can
+    be NULL if you are not interested in their values.
 
     Note that png_get_IHDR() returns png_uint_32 data into
     the application's width and height variables.
-    This is an unsafe situation if these are 16-bit
+    This is an unsafe situation if these are not png_uint_32
     variables, or if they are 32-bit variables on a 64-bit
     platform.  In such situations, the png_get_image_width()
     and png_get_image_height() functions described below are
@@ -5036,8 +5043,8 @@ where "rp" indicates a "restricted pointer".
 Error detection in some chunks has improved; in particular the iCCP chunk
 reader now does pretty complete validation of the basic format.  Some bad
 profiles that were previously accepted are now accepted with a warning or
-rejected, depending upon the png_set_benign_errors() setting, in particular the
-very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
+rejected, depending upon the png_set_benign_errors() setting, in particular
+the very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
 libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by
 means of
 
@@ -5048,7 +5055,7 @@ means of
     #endif
 
 It's not a good idea to do this if you are using the "simplified API",
-which needs to be able to recognize an sRGB profile conveyed via the iCCP
+which needs to be able to recognize sRGB profiles conveyed via the iCCP
 chunk.
 
 The PNG spec requirement that only grayscale profiles may appear in images
@@ -5325,13 +5332,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 XVII. Y2K Compliance in libpng
 
-January 27, 2015
+February 23, 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 1.7.0beta47 are Y2K compliant.  It is my belief that earlier
+upward through 1.7.0beta53 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has two year fields.  One is a 2-byte unsigned integer

libpng.3

@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "January 27, 2015"
+.TH LIBPNG 3 "February 23, 2015"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta47
+libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta53
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@@ -494,7 +494,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.7.0beta47 - January 27, 2015
+ libpng version 1.7.0beta53 - February 23, 2015
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
@@ -505,7 +505,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.7.0beta47 - January 27, 2015
+ libpng versions 0.97, January 1998, through 1.7.0beta53 - February 23, 2015
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
@@ -928,6 +928,10 @@ You can #define PNG_ABORT to a function or other C code that does something
 more useful than abort(), as long as your function does not
 return.
 
+If you do this, you cannot #define PNG_SIMPLIFIED_READ_SUPPORTED or
+PNG_SIMPLIFIED_WRITE_SUPPORTED, because the simplified API requires
+setjmp() support.
+
 Now you need to set up the input code.  The default for libpng is to
 use the C function fread().  If you use this, you will need to pass a
 valid FILE * in the function png_init_io().  Be sure that the file is
@@ -1675,7 +1679,10 @@ row_pointers prior to calling png_read_png() with
    png_set_rows(png_ptr, info_ptr, &row_pointers);
 
 Alternatively you could allocate your image in one big block and define
-row_pointers[i] to point into the proper places in your block.
+row_pointers[i] to point into the proper places in your block.  If
+you do this, be sure to call png_read_update_info() described below,
+to update the "rowbytes" value to account for any transformations that
+change the number of bytes per row before you use it to allocate your block.
 
 If you use png_set_rows(), the application is responsible for freeing
 row_pointers (and row_pointers[i], if they were separately allocated).
@@ -1760,13 +1767,13 @@ in until png_read_end() has read the chunk data following the image.
                      the PNG datastream is embedded in
                      a MNG-1.0 datastream)
 
-    Any or all of color_tye, bit_depth, interlace_type,
-    compression_type, or filter_method can be NULL if you
-    are not interested in their values.
+    Any of width, height, color_type, bit_depth,
+    interlace_type, compression_type, or filter_method can
+    be NULL if you are not interested in their values.
 
     Note that png_get_IHDR() returns png_uint_32 data into
     the application's width and height variables.
-    This is an unsafe situation if these are 16-bit
+    This is an unsafe situation if these are not png_uint_32
     variables, or if they are 32-bit variables on a 64-bit
     platform.  In such situations, the png_get_image_width()
     and png_get_image_height() functions described below are
@@ -5530,8 +5537,8 @@ where "rp" indicates a "restricted pointer".
 Error detection in some chunks has improved; in particular the iCCP chunk
 reader now does pretty complete validation of the basic format.  Some bad
 profiles that were previously accepted are now accepted with a warning or
-rejected, depending upon the png_set_benign_errors() setting, in particular the
-very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
+rejected, depending upon the png_set_benign_errors() setting, in particular
+the very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
 libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by
 means of
 
@@ -5542,7 +5549,7 @@ means of
     #endif
 
 It's not a good idea to do this if you are using the "simplified API",
-which needs to be able to recognize an sRGB profile conveyed via the iCCP
+which needs to be able to recognize sRGB profiles conveyed via the iCCP
 chunk.
 
 The PNG spec requirement that only grayscale profiles may appear in images
@@ -5819,13 +5826,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 .SH XVII. Y2K Compliance in libpng
 
-January 27, 2015
+February 23, 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 1.7.0beta47 are Y2K compliant.  It is my belief that earlier
+upward through 1.7.0beta53 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
@@ -6032,7 +6039,7 @@ the first widely used release:
  1.5.7               15    10507  15.so.15.7[.0]
  1.6.0beta01-37      16    10600  16.so.16.0[.0]
  1.7.0alpha01-10     17    10700  17.so.17.0[.0]
- 1.7.0beta01-47      17    10700  17.so.17.0[.0]
+ 1.7.0beta01-53      17    10700  17.so.17.0[.0]
 
 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@@ -6089,7 +6096,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.7.0beta47 - January 27, 2015:
+Libpng version 1.7.0beta53 - February 23, 2015:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -6112,7 +6119,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.7.0beta47, January 27, 2015, are
+libpng versions 1.2.6, August 15, 2004, through 1.7.0beta53, February 23, 2015, are
 Copyright (c) 2004,2006-2007 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
@@ -6211,7 +6218,7 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-January 27, 2015
+February 23, 2015
 
 .\" end of man page
 

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "January 27, 2015"
+.TH LIBPNGPF 3 "February 23, 2015"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta47
+libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta53
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "January 27, 2015"
+.TH PNG 5 "February 23, 2015"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION

png.c

@@ -14,7 +14,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_7_0beta47 Your_png_h_is_not_version_1_7_0beta47;
+typedef png_libpng_version_1_7_0beta53 Your_png_h_is_not_version_1_7_0beta53;
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
@@ -217,6 +217,7 @@ png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
    /* Success return. */
    return 1;
 }
+
 /* Generic function to create a png_struct for either read or write - this
  * contains the common initialization.
  */
@@ -693,13 +694,13 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.7.0beta47 - January 27, 2015" PNG_STRING_NEWLINE \
+     "libpng version 1.7.0beta53 - February 23, 2015" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2015 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE;
 #  else
-      return "libpng version 1.7.0beta47 - January 27, 2015\
+      return "libpng version 1.7.0beta53 - February 23, 2015\
       Copyright (c) 1998-2015 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -2074,7 +2075,8 @@ png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace,
    return 1; /* success, maybe with warnings */
 }
 
-#if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0
+#ifdef PNG_sRGB_SUPPORTED
+#if PNG_sRGB_PROFILE_CHECKS >= 0
 /* Information about the known ICC sRGB profiles */
 static const struct
 {
@@ -2256,9 +2258,8 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
 
    return 0; /* no match */
 }
-#endif
+#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */
 
-#ifdef PNG_sRGB_SUPPORTED
 void /* PRIVATE */
 png_icc_set_sRGB(png_const_structrp png_ptr,
    png_colorspacerp colorspace, png_const_bytep profile, uLong adler)
@@ -2272,7 +2273,7 @@ png_icc_set_sRGB(png_const_structrp png_ptr,
       (void)png_colorspace_set_sRGB(png_ptr, colorspace,
          (int)/*already checked*/png_get_uint_32(profile+64));
 }
-#endif /* READ_sRGB */
+#endif /* sRGB */
 
 int /* PRIVATE */
 png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace,
@@ -2364,7 +2365,7 @@ png_colorspace_set_rgb_coefficients(png_structrp png_ptr)
          png_error(png_ptr, "internal error handling cHRM->XYZ");
    }
 }
-#endif
+#endif /* READ_RGB_TO_GRAY */
 
 #endif /* COLORSPACE */
 
@@ -3324,23 +3325,14 @@ static png_fixed_point
 png_product2(png_fixed_point a, png_fixed_point b)
 {
    /* The required result is 1/a * 1/b; the following preserves accuracy. */
-#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
-   double r = a * 1E-5;
-   r *= b;
-   r = floor(r+.5);
-
-   if (r <= 2147483647. && r >= -2147483648.)
-      return (png_fixed_point)r;
-#else
    png_fixed_point res;
 
    if (png_muldiv(&res, a, b, 100000) != 0)
       return res;
-#endif
 
    return 0; /* overflow */
 }
-#endif
+#endif /* FLOATING_ARITHMETIC */
 
 /* The inverse of the above. */
 png_fixed_point
@@ -3356,18 +3348,18 @@ png_reciprocal2(png_fixed_point a, png_fixed_point b)
 
       if (r <= 2147483647. && r >= -2147483648.)
          return (png_fixed_point)r;
-#else
-      /* This may overflow because the range of png_fixed_point isn't
-       * symmetric, but this API is only used for the product of file and
-       * screen gamma so it doesn't matter that the smallest number it can
-       * produce is 1/21474, not 1/100000
-       */
-      png_fixed_point res = png_product2(a, b);
-
-      if (res != 0)
-         return png_reciprocal(res);
-#endif
    }
+#else
+   /* This may overflow because the range of png_fixed_point isn't
+    * symmetric, but this API is only used for the product of file and
+    * screen gamma so it doesn't matter that the smallest number it can
+    * produce is 1/21474, not 1/100000
+    */
+   png_fixed_point res = png_product2(a, b);
+
+   if (res != 0)
+      return png_reciprocal(res);
+#endif
 
    return 0; /* overflow */
 }

png.h

@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.7.0beta47 - January 27, 2015
+ * libpng version 1.7.0beta53 - February 23, 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.)
@@ -11,7 +11,7 @@
  * 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 1.7.0beta47 - January 27, 2015: Glenn
+ *   libpng versions 0.97, January 1998, through 1.7.0beta53 - February 23, 2015: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -168,7 +168,7 @@
  *    1.5.7                   15    10507  15.so.15.7[.0]
  *    1.6.0beta01-37          16    10600  16.so.16.0[.0]
  *    1.7.0alpha01-10         17    10700  17.so.17.0[.0]
- *    1.7.0beta01-47          17    10700  17.so.17.0[.0]
+ *    1.7.0beta01-53          17    10700  17.so.17.0[.0]
  *
  *   Henceforth the source version will match the shared-library major
  *   and minor numbers; the shared-library major version number will be
@@ -200,8 +200,8 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.7.0beta47, January 27, 2015, are
- * Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are
+ * libpng versions 1.2.6, August 15, 2004, through 1.7.0beta53, February 23, 2015, are
+ * Copyright (c) 2004, 2006-2015 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:
  *
@@ -312,13 +312,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    January 27, 2015
+ *    February 23, 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 1.7.0beta47 are Y2K compliant.  It is my belief that
+ *    upward through 1.7.0beta53 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
@@ -380,9 +380,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.7.0beta47"
+#define PNG_LIBPNG_VER_STRING "1.7.0beta53"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.7.0beta47 - January 27, 2015\n"
+     " libpng version 1.7.0beta53 - February 23, 2015\n"
 
 #define PNG_LIBPNG_VER_SONUM   17
 #define PNG_LIBPNG_VER_DLLNUM  17
@@ -396,7 +396,7 @@
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
 
-#define PNG_LIBPNG_VER_BUILD  47
+#define PNG_LIBPNG_VER_BUILD  53
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
@@ -647,7 +647,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_7_0beta47;
+typedef char* png_libpng_version_1_7_0beta53;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -1748,6 +1748,7 @@ PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
  * 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));
 
@@ -1765,7 +1766,7 @@ PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
 
 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 */
@@ -1787,6 +1788,7 @@ PNG_EXPORT(225, void, png_set_text_compression_window_bits,
 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
     int method));
 #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,

pngconf.h

@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.7.0beta47 - January 27, 2015
+ * libpng version 1.7.0beta53 - February 23, 2015
  *
  * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)

pngdebug.h

@@ -1,12 +1,11 @@
 
 /* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
  *
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 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.)
  *
- * Last changed in libpng 1.6.8 [December 19, 2013]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h

pnginfo.h

@@ -1,12 +1,11 @@
 
 /* pnginfo.h - header file for PNG reference library
  *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
  * Copyright (c) 1998-2013 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.)
  *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h

pngpriv.h

@@ -1,13 +1,11 @@
 
 /* pngpriv.h - private declarations for use inside libpng
  *
- * For conditions of distribution and use, see copyright notice in png.h
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
  * 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.)
  *
- * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h

pngread.c

@@ -2285,8 +2285,14 @@ png_image_read_colormap(png_voidp argument)
                      output_processing = PNG_CMAP_NONE;
                      break;
                   }
-
+#ifdef __COVERITY__
+                 /* Coverity claims that output_encoding cannot be 2 (P_LINEAR)
+                  * here.
+                  */
+                  back_alpha = 255;
+#else
                   back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
+#endif
                }
 
                /* output_processing means that the libpng-processed row will be
@@ -2411,7 +2417,14 @@ png_image_read_colormap(png_voidp argument)
                 */
                background_index = i;
                png_create_colormap_entry(display, i++, back_r, back_g, back_b,
-                  output_encoding == P_LINEAR ? 65535U : 255U, output_encoding);
+#ifdef __COVERITY__
+                 /* Coverity claims that output_encoding cannot be 2 (P_LINEAR)
+                  * here.
+                  */ 255U,
+#else
+                  output_encoding == P_LINEAR ? 65535U : 255U,
+#endif
+                  output_encoding);
 
                /* For non-opaque input composite on the sRGB background - this
                 * requires inverting the encoding for each component.  The input

pngrio.c

@@ -1,8 +1,8 @@
 
 /* pngrio.c - functions for data input
  *
- * Last changed in libpng 1.6.15 [November 20, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.17 [(PENDING RELEASE)]
+ * 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.)
  *

pngrtran.c

@@ -2991,18 +2991,11 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
             for (i = 0; i < row_width; i++)
             {
                png_uint_16 red, green, blue, w;
-
-#if 0 /* Coverity doesn't like this */
-               red   = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
-               green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
-               blue  = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
-#else
                png_byte hi,lo;
 
                hi=*(sp)++; lo=*(sp)++; red   = (png_uint_16)((hi << 8) | (lo));
                hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
                hi=*(sp)++; lo=*(sp)++; blue  = (png_uint_16)((hi << 8) | (lo));
-#endif
 
                if (red == green && red == blue)
                {
@@ -3047,10 +3040,11 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
             for (i = 0; i < row_width; i++)
             {
                png_uint_16 red, green, blue, gray16;
+               png_byte hi,lo;
 
-               red   = (png_uint_16)(((*(sp)) << 8) | *(sp + 1)); sp += 2;
-               green = (png_uint_16)(((*(sp)) << 8) | *(sp + 1)); sp += 2;
-               blue  = (png_uint_16)(((*(sp)) << 8) | *(sp + 1)); sp += 2;
+               hi=*(sp)++; lo=*(sp)++; red   = (png_uint_16)((hi << 8) | (lo));
+               hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
+               hi=*(sp)++; lo=*(sp)++; blue  = (png_uint_16)((hi << 8) | (lo));
 
                if (red != green || red != blue)
                   rgb_error |= 1;

pngrutil.c

@@ -2,7 +2,7 @@
 /* pngrutil.c - utilities to read a PNG file
  *
  * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * 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.)
  *
@@ -1316,7 +1316,7 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
    }
 
    /* If a colorspace error has already been output skip this chunk */
-   if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
+   if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
    {
       png_crc_finish(png_ptr, length);
       return;

pngstruct.h

@@ -1,12 +1,11 @@
 
 /* pngstruct.h - header file for PNG reference library
  *
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
  * 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.)
  *
- * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -341,17 +340,9 @@ struct png_struct_def
    size_t    big_row_buf_size; /* Actual size of both */
 #endif
 
-#ifdef PNG_WRITE_SUPPORTED
-   /* This is somewhat excessive, there is no obvious reason on write to
-    * allocate a buffer for each possible filtered row, only for the one being
-    * tested and the current best.
-    *
-    * TODO: fix this
-    */
-   png_bytep sub_row;         /* buffer to save "sub" row when filtering */
-   png_bytep up_row;          /* buffer to save "up" row when filtering */
-   png_bytep avg_row;         /* buffer to save "avg" row when filtering */
-   png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   png_bytep try_row;    /* buffer to save trial row when filtering */
+   png_bytep tst_row;    /* buffer to save best trial row when filtering */
 #endif
 
    /* UNKNOWN CHUNK HANDLING */

pngtest.c

@@ -1,8 +1,8 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.6.15 [November 20, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.17 [(PENDING RELEASE)]
+ * 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.)
  *
@@ -1701,6 +1701,8 @@ main(int argc, char *argv[])
    int multiple = 0;
    int ierror = 0;
 
+   png_structp dummy_ptr;
+
    fprintf(STDERR, "\n Testing libpng version %s\n", PNG_LIBPNG_VER_STRING);
    fprintf(STDERR, "   with zlib   version %s\n", ZLIB_VERSION);
    fprintf(STDERR, "%s", png_get_copyright(NULL));
@@ -1994,6 +1996,24 @@ main(int argc, char *argv[])
    else
       fprintf(STDERR, " libpng FAILS test\n");
 
+   dummy_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+   fprintf(STDERR, " Default limits:\n");
+   fprintf(STDERR, "  width_max  = %lu\n",
+      (unsigned long) png_get_user_width_max(dummy_ptr));
+   fprintf(STDERR, "  height_max = %lu\n",
+      (unsigned long) png_get_user_height_max(dummy_ptr));
+   if (png_get_chunk_cache_max(dummy_ptr) == 0)
+      fprintf(STDERR, "  cache_max  = unlimited\n");
+   else
+      fprintf(STDERR, "  cache_max  = %lu\n",
+         (unsigned long) png_get_chunk_cache_max(dummy_ptr));
+   if (png_get_chunk_malloc_max(dummy_ptr) == 0)
+      fprintf(STDERR, "  malloc_max = unlimited\n");
+   else
+      fprintf(STDERR, "  malloc_max = %lu\n",
+         (unsigned long) png_get_chunk_malloc_max(dummy_ptr));
+   png_destroy_read_struct(&dummy_ptr, NULL, NULL);
+
    return (int)(ierror != 0);
 }
 #else
@@ -2008,4 +2028,4 @@ main(void)
 #endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_7_0beta47 Your_png_h_is_not_version_1_7_0beta47;
+typedef png_libpng_version_1_7_0beta53 Your_png_h_is_not_version_1_7_0beta53;

pngusr.dfa

@@ -12,4 +12,4 @@
 # @# define PNG_USER_WIDTH_MAX 65535
 # @# define PNG_USER_HEIGHT_MAX 65535
 # @# define PNG_USER_CHUNK_CACHE_MAX 256
-# @# define PNG_USER_CHUNK_MALLOC_MAX 1000000
+# @# define PNG_USER_CHUNK_MALLOC_MAX 640000

pngwrite.c

@@ -2,7 +2,7 @@
 /* pngwrite.c - general routines to write a PNG file
  *
  * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * 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.)
  *
@@ -942,15 +942,11 @@ png_write_destroy(png_structrp png_ptr)
    png_ptr->row_buf = NULL;
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    png_free(png_ptr, png_ptr->prev_row);
-   png_free(png_ptr, png_ptr->sub_row);
-   png_free(png_ptr, png_ptr->up_row);
-   png_free(png_ptr, png_ptr->avg_row);
-   png_free(png_ptr, png_ptr->paeth_row);
+   png_free(png_ptr, png_ptr->try_row);
+   png_free(png_ptr, png_ptr->tst_row);
    png_ptr->prev_row = NULL;
-   png_ptr->sub_row = NULL;
-   png_ptr->up_row = NULL;
-   png_ptr->avg_row = NULL;
-   png_ptr->paeth_row = NULL;
+   png_ptr->try_row = NULL;
+   png_ptr->tst_row = NULL;
 #endif
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
@@ -1065,8 +1061,8 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
        * it is too late to start using the filters that need it, since we
        * will be missing the data in the previous row.  If an application
        * wants to start and stop using particular filters during compression,
-       * it should start out with all of the filters, and then add and
-       * remove them after the start of compression.
+       * it should start out with all of the filters, and then remove them
+       * or add them back after the start of compression.
        *
        * NOTE: this is a nasty constraint on the code, because it means that the
        * prev_row buffer must be maintained even if there are currently no
@@ -1354,6 +1350,7 @@ png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method,
 #endif /* FIXED_POINT */
 #endif /* WRITE_WEIGHTED_FILTER */
 
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
 void PNGAPI
 png_set_compression_level(png_structrp png_ptr, int level)
 {
@@ -1436,6 +1433,7 @@ png_set_compression_method(png_structrp png_ptr, int method)
 
    png_ptr->zlib_method = method;
 }
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
 
 /* The following were added to libpng-1.5.4 */
 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
@@ -2268,7 +2266,9 @@ png_image_write_main(png_voidp argument)
        * it about 50 times.  The speed-up in pngstest was about 10-20% of the
        * total (user) time on a heavily loaded system.
        */
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
       png_set_compression_level(png_ptr, 3);
+#endif
    }
 
    /* Check for the cases that currently require a pre-transform on the row

pngwutil.c

@@ -1943,7 +1943,7 @@ png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)
 #ifdef PNG_WRITE_FILTER_SUPPORTED
 void /* PRIVATE */
 png_write_alloc_filter_row_buffers(png_structrp png_ptr, int filters)
-   /* Allocate row buffers for any filters that need them, this is also called
+   /* Allocate row buffers for any filters that need them. This is also called
     * from png_set_filter if the filters are changed during write to ensure that
     * the required buffers exist.  png_set_filter ensures that up/avg/paeth are
     * only set if png_ptr->prev_row is allocated.
@@ -1954,29 +1954,28 @@ png_write_alloc_filter_row_buffers(png_structrp png_ptr, int filters)
     */
    png_alloc_size_t buf_size = png_ptr->rowbytes + 1;
 
-   if ((filters & PNG_FILTER_SUB) != 0 && png_ptr->sub_row == NULL)
+   if (((filters & (PNG_FILTER_SUB | PNG_FILTER_UP | PNG_FILTER_AVG |
+       PNG_FILTER_PAETH)) != 0) && png_ptr->try_row == NULL)
    {
-      png_ptr->sub_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
-      png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
-   }
+      int num_filters = 0;
 
-   if ((filters & PNG_FILTER_UP) != 0 && png_ptr->up_row == NULL)
-   {
-      png_ptr->up_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
-      png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
-   }
+      png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
 
-   if ((filters & PNG_FILTER_AVG) != 0 && png_ptr->avg_row == NULL)
-   {
-      png_ptr->avg_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
-      png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
-   }
+      if (filters & PNG_FILTER_SUB)
+         num_filters++;
 
-   if ((filters & PNG_FILTER_PAETH) != 0 && png_ptr->paeth_row == NULL)
-   {
-      png_ptr->paeth_row = png_voidcast(png_bytep, png_malloc(png_ptr,
-         buf_size));
-      png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
+      if (filters & PNG_FILTER_UP)
+         num_filters++;
+
+      if (filters & PNG_FILTER_AVG)
+         num_filters++;
+
+      if (filters & PNG_FILTER_PAETH)
+         num_filters++;
+
+      if (num_filters > 1)
+         png_ptr->tst_row = png_voidcast(png_bytep,
+             png_malloc(png_ptr, buf_size));
    }
 }
 #endif /* WRITE_FILTER */
@@ -2352,42 +2351,232 @@ static void /* PRIVATE */
 png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
    png_size_t row_bytes);
 
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+static png_size_t /* PRIVATE */
+png_setup_sub_row(png_structrp png_ptr, const png_uint_32 bpp,
+    const png_size_t row_bytes, const png_size_t lmins)
+{
+   png_bytep rp, dp, lp;
+   png_size_t i;
+   png_size_t sum = 0;
+   int v;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
+        i++, rp++, dp++)
+   {
+      v = *dp = *rp;
+      sum += (v < 128) ? v : 256 - v;
+   }
+
+   for (lp = png_ptr->row_buf + 1; i < row_bytes;
+      i++, rp++, lp++, dp++)
+   {
+      v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+      sum += (v < 128) ? v : 256 - v;
+
+      if (sum > lmins)  /* We are already worse, don't continue. */
+        break;
+   }
+
+   return (sum);
+}
+
+static png_size_t /* PRIVATE */
+png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes,
+    const png_size_t lmins)
+{
+   png_bytep rp, dp, pp;
+   png_size_t i;
+   png_size_t sum = 0;
+   int v;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+       pp = png_ptr->prev_row + 1; i < row_bytes;
+       i++, rp++, pp++, dp++)
+   {
+      v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+      sum += (v < 128) ? v : 256 - v;
+
+      if (sum > lmins)  /* We are already worse, don't continue. */
+        break;
+   }
+
+   return (sum);
+}
+
+static png_size_t /* PRIVATE */
+png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp,
+      const png_size_t row_bytes, const png_size_t lmins)
+{
+   png_bytep rp, dp, pp, lp;
+   png_uint_32 i;
+   png_size_t sum = 0;
+   int v;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+        pp = png_ptr->prev_row + 1; i < bpp; i++)
+   {
+      v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+
+      sum += (v < 128) ? v : 256 - v;
+   }
+
+   for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
+   {
+      v = *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+          & 0xff);
+
+      sum += (v < 128) ? v : 256 - v;
+
+      if (sum > lmins)  /* We are already worse, don't continue. */
+        break;
+   }
+
+   return (sum);
+}
+
+static png_size_t /* PRIVATE */
+png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp,
+    const png_size_t row_bytes, const png_size_t lmins)
+{
+   png_bytep rp, dp, pp, cp, lp;
+   png_size_t i;
+   png_size_t sum = 0;
+   int v;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+       pp = png_ptr->prev_row + 1; i < bpp; i++)
+   {
+      v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+
+      sum += (v < 128) ? v : 256 - v;
+   }
+
+   for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
+        i++)
+   {
+      int a, b, c, pa, pb, pc, p;
+
+      b = *pp++;
+      c = *cp++;
+      a = *lp++;
+
+      p = b - c;
+      pc = a - c;
+
+#ifdef PNG_USE_ABS
+      pa = abs(p);
+      pb = abs(pc);
+      pc = abs(p + pc);
+#else
+      pa = p < 0 ? -p : p;
+      pb = pc < 0 ? -pc : pc;
+      pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+      p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+
+      v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+
+      sum += (v < 128) ? v : 256 - v;
+
+      if (sum > lmins)  /* We are already worse, don't continue. */
+        break;
+   }
+
+   return (sum);
+}
+
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+
 #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
 #define PNG_HISHIFT 10
 #define PNG_LOMASK ((png_uint_32)0xffffL)
 #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
+
+static png_size_t /* PRIVATE */
+png_increase_lmins(png_structrp png_ptr, png_size_t lmins)
+{
+   /* We temporarily increase the "minimum sum" by the factor we
+    * would reduce the sum of this filter, so that we can do the
+    * early exit comparison without scaling the sum each time.
+    */
+   int j;
+   png_uint_32 lmhi, lmlo;
+   lmlo = lmins & PNG_LOMASK;
+   lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+
+   for (j = 0; j < png_ptr->num_prev_filters; j++)
+   {
+      if (png_ptr->prev_filters[j] == png_ptr->try_row[0])
+      {
+         lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
+             PNG_WEIGHT_SHIFT;
+
+         lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
+             PNG_WEIGHT_SHIFT;
+      }
+   }
+
+   lmlo = (lmlo * png_ptr->inv_filter_costs[png_ptr->try_row[0]]) >>
+       PNG_COST_SHIFT;
+
+   lmhi = (lmhi * png_ptr->inv_filter_costs[png_ptr->try_row[0]]) >>
+       PNG_COST_SHIFT;
+
+   if (lmhi > PNG_HIMASK)
+      lmins = PNG_MAXSUM;
+
+   else
+      lmins = (lmhi << PNG_HISHIFT) + lmlo;
+
+   return (lmins);
+}
+#endif /* WRITE_WEIGHTED_FILTER */
+
+#endif /* WRITE_FILTER */
+
 void /* PRIVATE */
 png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
 {
-   png_bytep best_row;
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-   png_bytep prev_row, row_buf;
-   png_uint_32 mins, bpp;
+#ifndef PNG_WRITE_FILTER_SUPPORTED
+   png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1);
+#else
    png_byte filter_to_do = png_ptr->do_filter;
-   png_size_t row_bytes = row_info->rowbytes;
+   png_bytep row_buf;
+   png_bytep best_row;
+   png_uint_32 bpp;
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
    int num_p_filters = png_ptr->num_prev_filters;
 #endif
+   png_size_t mins;
+   png_size_t row_bytes = row_info->rowbytes;
 
    png_debug(1, "in png_write_find_filter");
 
 #ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-  if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
-  {
+   if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
+   {
      /* These will never be selected so we need not test them. */
      filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
-  }
+   }
 #endif
 
    /* Find out how many bytes offset each pixel is */
    bpp = (row_info->pixel_depth + 7) >> 3;
 
-   prev_row = png_ptr->prev_row;
-#endif
-   best_row = png_ptr->row_buf;
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-   row_buf = best_row;
-   mins = PNG_MAXSUM;
+   row_buf = png_ptr->row_buf;
+   mins = PNG_SIZE_MAX - 256/* so we can detect potential overflow of the
+                               running sum */;
 
    /* The prediction method we use is to find which method provides the
     * smallest value when summing the absolute values of the distances
@@ -2417,19 +2606,16 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
    /* We don't need to test the 'no filter' case if this is the only filter
     * that has been chosen, as it doesn't actually do anything to the data.
     */
+   best_row = png_ptr->row_buf;
+
+
    if ((filter_to_do & PNG_FILTER_NONE) != 0 && filter_to_do != PNG_FILTER_NONE)
    {
       png_bytep rp;
-      png_uint_32 sum = 0;
+      png_size_t sum = 0;
       png_size_t i;
       int v;
 
-      for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
-      {
-         v = *rp;
-         sum += (v < 128) ? v : 256 - v;
-      }
-
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
       {
@@ -2468,6 +2654,28 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }
 #endif
+
+      if (PNG_SIZE_MAX/128 <= row_bytes)
+      {
+         for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
+         {
+            /* Check for overflow */
+            if (sum > PNG_SIZE_MAX/128 - 256)
+               break;
+
+            v = *rp;
+            sum += (v < 128) ? v : 256 - v;
+         }
+      }
+      else /* Overflow is not possible */
+      {
+         for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
+         {
+            v = *rp;
+            sum += (v < 128) ? v : 256 - v;
+         }
+      }
+
       mins = sum;
    }
 
@@ -2475,87 +2683,21 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
    if (filter_to_do == PNG_FILTER_SUB)
    /* It's the only filter so no testing is needed */
    {
-      png_bytep rp, lp, dp;
-      png_size_t i;
-
-      for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
-           i++, rp++, dp++)
-      {
-         *dp = *rp;
-      }
-
-      for (lp = row_buf + 1; i < row_bytes;
-         i++, rp++, lp++, dp++)
-      {
-         *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
-      }
-
-      best_row = png_ptr->sub_row;
+      (void) png_setup_sub_row(png_ptr, bpp, row_bytes, mins); 
+      best_row = png_ptr->try_row;
    }
 
    else if ((filter_to_do & PNG_FILTER_SUB) != 0)
    {
-      png_bytep rp, dp, lp;
-      png_uint_32 sum = 0, lmins = mins;
-      png_size_t i;
-      int v;
-
+      png_size_t sum;
+      png_size_t lmins = mins;
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      /* We temporarily increase the "minimum sum" by the factor we
-       * would reduce the sum of this filter, so that we can do the
-       * early exit comparison without scaling the sum each time.
-       */
+      png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-             PNG_COST_SHIFT;
-
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-             PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
+         lmins = png_increase_lmins(png_ptr, lmins);
 #endif
 
-      for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
-           i++, rp++, dp++)
-      {
-         v = *dp = *rp;
-
-         sum += (v < 128) ? v : 256 - v;
-      }
-
-      for (lp = row_buf + 1; i < row_bytes;
-         i++, rp++, lp++, dp++)
-      {
-         v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
-
-         sum += (v < 128) ? v : 256 - v;
-
-         if (sum > lmins)  /* We are already worse, don't continue. */
-            break;
-      }
+      sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins); 
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
@@ -2594,78 +2736,33 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
       if (sum < mins)
       {
          mins = sum;
-         best_row = png_ptr->sub_row;
+         best_row = png_ptr->try_row;
+         if (png_ptr->tst_row != NULL)
+         {
+            png_ptr->try_row = png_ptr->tst_row;
+            png_ptr->tst_row = best_row;
+         }
       }
    }
 
    /* Up filter */
    if (filter_to_do == PNG_FILTER_UP)
    {
-      png_bytep rp, dp, pp;
-      png_size_t i;
-
-      for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
-          pp = prev_row + 1; i < row_bytes;
-          i++, rp++, pp++, dp++)
-      {
-         *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
-      }
-
-      best_row = png_ptr->up_row;
+      (void) png_setup_up_row(png_ptr, row_bytes, mins);
+      best_row = png_ptr->try_row;
    }
 
    else if ((filter_to_do & PNG_FILTER_UP) != 0)
    {
-      png_bytep rp, dp, pp;
-      png_uint_32 sum = 0, lmins = mins;
-      png_size_t i;
-      int v;
-
-
+      png_size_t sum;
+      png_size_t lmins = mins;
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
-             PNG_COST_SHIFT;
-
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
-             PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
+         lmins = png_increase_lmins(png_ptr, lmins);
 #endif
 
-      for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
-          pp = prev_row + 1; i < row_bytes; i++)
-      {
-         v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
-
-         sum += (v < 128) ? v : 256 - v;
-
-         if (sum > lmins)  /* We are already worse, don't continue. */
-            break;
-      }
+      sum = png_setup_up_row(png_ptr, row_bytes, lmins); 
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
@@ -2704,89 +2801,33 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
       if (sum < mins)
       {
          mins = sum;
-         best_row = png_ptr->up_row;
+         best_row = png_ptr->try_row;
+         if (png_ptr->tst_row != NULL)
+         {
+            png_ptr->try_row = png_ptr->tst_row;
+            png_ptr->tst_row = best_row;
+         }
       }
    }
 
    /* Avg filter */
    if (filter_to_do == PNG_FILTER_AVG)
    {
-      png_bytep rp, dp, pp, lp;
-      png_uint_32 i;
-
-      for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
-           pp = prev_row + 1; i < bpp; i++)
-      {
-         *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
-      }
-
-      for (lp = row_buf + 1; i < row_bytes; i++)
-      {
-         *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
-                 & 0xff);
-      }
-      best_row = png_ptr->avg_row;
+      (void) png_setup_avg_row(png_ptr, bpp, row_bytes, mins);
+      best_row = png_ptr->try_row;
    }
 
    else if ((filter_to_do & PNG_FILTER_AVG) != 0)
    {
-      png_bytep rp, dp, pp, lp;
-      png_uint_32 sum = 0, lmins = mins;
-      png_size_t i;
-      int v;
-
+      png_size_t sum;
+      png_size_t lmins = mins;
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
-             PNG_COST_SHIFT;
-
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
-             PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
+         lmins = png_increase_lmins(png_ptr, lmins);
 #endif
 
-      for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
-           pp = prev_row + 1; i < bpp; i++)
-      {
-         v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
-
-         sum += (v < 128) ? v : 256 - v;
-      }
-
-      for (lp = row_buf + 1; i < row_bytes; i++)
-      {
-         v = *dp++ =
-             (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
-
-         sum += (v < 128) ? v : 256 - v;
-
-         if (sum > lmins)  /* We are already worse, don't continue. */
-            break;
-      }
+      sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins);
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
@@ -2825,143 +2866,33 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
       if (sum < mins)
       {
          mins = sum;
-         best_row = png_ptr->avg_row;
+         best_row = png_ptr->try_row;
+         if (png_ptr->tst_row != NULL)
+         {
+            png_ptr->try_row = png_ptr->tst_row;
+            png_ptr->tst_row = best_row;
+         }
       }
    }
 
    /* Paeth filter */
    if ((filter_to_do == PNG_FILTER_PAETH) != 0)
    {
-      png_bytep rp, dp, pp, cp, lp;
-      png_size_t i;
-
-      for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
-          pp = prev_row + 1; i < bpp; i++)
-      {
-         *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
-      }
-
-      for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
-      {
-         int a, b, c, pa, pb, pc, p;
-
-         b = *pp++;
-         c = *cp++;
-         a = *lp++;
-
-         p = b - c;
-         pc = a - c;
-
-#ifdef PNG_USE_ABS
-         pa = abs(p);
-         pb = abs(pc);
-         pc = abs(p + pc);
-#else
-         pa = p < 0 ? -p : p;
-         pb = pc < 0 ? -pc : pc;
-         pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-#endif
-
-         p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
-
-         *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
-      }
-      best_row = png_ptr->paeth_row;
+      (void) png_setup_paeth_row(png_ptr, bpp, row_bytes, mins);
+      best_row = png_ptr->try_row;
    }
 
    else if ((filter_to_do & PNG_FILTER_PAETH) != 0)
    {
-      png_bytep rp, dp, pp, cp, lp;
-      png_uint_32 sum = 0, lmins = mins;
-      png_size_t i;
-      int v;
-
+      png_size_t sum;
+      png_size_t lmins = mins;
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-             PNG_COST_SHIFT;
-
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-             PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
+         lmins = png_increase_lmins(png_ptr, lmins);
 #endif
 
-      for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
-          pp = prev_row + 1; i < bpp; i++)
-      {
-         v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
-
-         sum += (v < 128) ? v : 256 - v;
-      }
-
-      for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
-      {
-         int a, b, c, pa, pb, pc, p;
-
-         b = *pp++;
-         c = *cp++;
-         a = *lp++;
-
-#ifndef PNG_SLOW_PAETH
-         p = b - c;
-         pc = a - c;
-#ifdef PNG_USE_ABS
-         pa = abs(p);
-         pb = abs(pc);
-         pc = abs(p + pc);
-#else
-         pa = p < 0 ? -p : p;
-         pb = pc < 0 ? -pc : pc;
-         pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-#endif
-         p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
-#else /* SLOW_PAETH */
-         p = a + b - c;
-         pa = abs(p - a);
-         pb = abs(p - b);
-         pc = abs(p - c);
-
-         if (pa <= pb && pa <= pc)
-            p = a;
-
-         else if (pb <= pc)
-            p = b;
-
-         else
-            p = c;
-#endif /* SLOW_PAETH */
-
-         v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
-
-         sum += (v < 128) ? v : 256 - v;
-
-         if (sum > lmins)  /* We are already worse, don't continue. */
-            break;
-      }
+      sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins);
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
@@ -2999,15 +2930,19 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
 
       if (sum < mins)
       {
-         best_row = png_ptr->paeth_row;
+         mins = sum;
+         best_row = png_ptr->try_row;
+         if (png_ptr->tst_row != NULL)
+         {
+            png_ptr->try_row = png_ptr->tst_row;
+            png_ptr->tst_row = best_row;
+         }
       }
    }
-#endif /* WRITE_FILTER */
 
    /* Do the actual writing of the filtered row data from the chosen filter. */
    png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
 
-#ifdef PNG_WRITE_FILTER_SUPPORTED
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
    /* Save the type of filter we picked this time for future calculations */
    if (png_ptr->num_prev_filters > 0)
@@ -3021,7 +2956,7 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
 
       png_ptr->prev_filters[j] = best_row[0];
    }
-#endif
+#endif /* WRITE_WEIGHTED_FILTER */
 #endif /* WRITE_FILTER */
 }
 

projects/vstudio/readme.txt

@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.7.0beta47 - January 27, 2015
+libpng version 1.7.0beta53 - February 23, 2015
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 

projects/vstudio/zlib.props

@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.7.0beta47 - January 27, 2015
+ * libpng version 1.7.0beta53 - February 23, 2015
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *

scripts/README.txt

@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.7.0beta47 - January 27, 2015
+Makefiles for  libpng version 1.7.0beta53 - February 23, 2015
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng17.so.17.1.7.0beta47)
+                       (gcc, creates libpng17.so.17.1.7.0beta53)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -33,12 +33,12 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
  makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
  makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng17.so.17.1.7.0beta47)
+                       creates libpng17.so.17.1.7.0beta53)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng17.so.17.1.7.0beta47)
+                       creates libpng17.so.17.1.7.0beta53)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng17.so.17.1.7.0beta47)
+                       creates libpng17.so.17.1.7.0beta53)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile

scripts/def.c

@@ -21,7 +21,7 @@ PNG_DFN "OS2 DESCRIPTION "PNG image compression library""
 PNG_DFN "OS2 CODE PRELOAD MOVEABLE DISCARDABLE"
 PNG_DFN ""
 PNG_DFN "EXPORTS"
-PNG_DFN ";Version 1.7.0beta47"
+PNG_DFN ";Version 1.7.0beta53"
 
 #define PNG_EXPORTA(ordinal, type, name, args, attributes)\
         PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"

scripts/libpng-config-head.in

@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.7.0beta47
+version=1.7.0beta53
 prefix=""
 libdir=""
 libs=""

scripts/libpng.pc.in

@@ -5,6 +5,6 @@ includedir=@includedir@/libpng17
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.7.0beta47
+Version: 1.7.0beta53
 Libs: -L${libdir} -lpng17
 Cflags: -I${includedir}

scripts/makefile.ne12bsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng17
 
 LIB=	png17
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.7.0beta47
+SHLIB_MINOR=	1.7.0beta53
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c

scripts/makefile.netbsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include
 
 LIB=	png
 SHLIB_MAJOR=	17
-SHLIB_MINOR=	1.7.0beta47
+SHLIB_MINOR=	1.7.0beta53
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c

scripts/makefile.openbsd

@@ -11,7 +11,7 @@ LIBDIR=	${PREFIX}/lib
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	17
-SHLIB_MINOR=	1.7.0beta47
+SHLIB_MINOR=	1.7.0beta53
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \

scripts/pnglibconf.dfa

@@ -395,7 +395,7 @@ option USER_LIMITS requires READ
 # USER_CHUNK_CACHE_MAX limit
 setting USER_WIDTH_MAX default        1000000 /* Use 0x7fffffff for unlimited */
 setting USER_HEIGHT_MAX default       1000000 /* Use 0x7fffffff for unlimited */
-setting USER_CHUNK_CACHE_MAX default      128 /* Use 0 for unlimited */
+setting USER_CHUNK_CACHE_MAX default     1000 /* Use 0 for unlimited */
 setting USER_CHUNK_MALLOC_MAX default 8000000 /* Use 0 for unlimited */
 
 # If this option is enabled APIs to set the above limits at run time are added;
@@ -542,6 +542,7 @@ option USER_TRANSFORM_INFO if READ_USER_TRANSFORM, WRITE_USER_TRANSFORM
 # non-IDAT chunks (zTXt, iTXt, iCCP, and unknown chunks).  This feature
 # was added at libpng-1.5.3.
 option WRITE_CUSTOMIZE_ZTXT_COMPRESSION requires WRITE
+option WRITE_CUSTOMIZE_COMPRESSION requires WRITE
 
 # Any chunks you are not interested in, you can undef here.  The
 # ones that allocate memory may be expecially important (hIST,

scripts/pnglibconf.h.prebuilt

@@ -1,8 +1,8 @@
-/* libpng 1.7.0beta47 STANDARD API DEFINITION */
+/* libpng 1.7.0beta53 STANDARD API DEFINITION */
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.7.0beta47 - January 27, 2015 */
+/* Libpng version 1.7.0beta53 - February 23, 2015 */
 
 /* Copyright (c) 1998-2014 Glenn Randers-Pehrson */
 
@@ -126,6 +126,7 @@
 #define PNG_WRITE_BGR_SUPPORTED
 #define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
 #define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
 #define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 #define PNG_WRITE_FILLER_SUPPORTED
 #define PNG_WRITE_FILTER_SUPPORTED
@@ -196,7 +197,7 @@
 #define PNG_QUANTIZE_RED_BITS 5
 #define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1)
 #define PNG_TEXT_Z_DEFAULT_STRATEGY 0
-#define PNG_USER_CHUNK_CACHE_MAX 128 /* Use 0 for unlimited */
+#define PNG_USER_CHUNK_CACHE_MAX 1000 /* Use 0 for unlimited */
 #define PNG_USER_CHUNK_MALLOC_MAX 8000000 /* Use 0 for unlimited */
 #define PNG_USER_HEIGHT_MAX 1000000 /* Use 0x7fffffff for unlimited */
 #define PNG_USER_WIDTH_MAX 1000000 /* Use 0x7fffffff for unlimited */

scripts/symbols.def

@@ -1,4 +1,4 @@
-;Version 1.7.0beta47
+;Version 1.7.0beta53
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng