Merge branch 'libpng17' into libpng17-buffer-enhancements

ANNOUNCE

@@ -972,6 +972,38 @@ Version 1.7.0beta69 [November 23, 2015]
     by flaviommedeiros).
   Fixed bug recently introduced in png_set_PLTE() that uses png_ptr
     not info_ptr.
+  Added pngvalid --transform --interlace test. This increases code
+    coverage by generating test cases with smaller length rows as a
+    result of the interlacing.  Without this packswap handling was
+    incompletely tested.
+  Fixed NO_WRITE_INTERLACE in pngvalid.c.  The support for writing
+    interlaced images directly from libpng 1.7 was unintentionally
+    disabled (INTERLACE_LAST was defined incorrectly, excluding the
+    interlaced images).  This obscured the fact that the transform and
+    error test case generators lacked the support for writing interlaced
+    images from libpng.
+  Transform rewrite: perform transforms in small chunks.  The intent
+    of this change is to reduce the memory footprint during transform
+    sequences by performing transforms in fixed (small) sized blocks of
+    pixels.  The change is incomplete; the filter code still works
+    row-by-row, so the whole tranform also works row-by-row. The intent
+    is to fix this so that everything works in small(ish) chunks.
+    At present the change has no discernable effect on pngvalid --speed
+    or pngstest with (e.g.) rgb-8-1.8.png; user time and (minor) page
+    faults are the same in old and new versions.  The same applies to
+    real-world 15MP PNG images; even on these the presence of the filter
+    code causes a cyclical progress through memory which will interfere
+    with any caching otherwise possible (useful word, 'otherwise'.) 
+  Read row buffer changes.  The read code now allocates one row buffer
+    of the size of the input PNG row and, only if required, one buffer of
+    the size of the output.  The output buffer is required for the
+    progressive reader (always) and for the sequential reader if libpng
+    is de-interlacing an image (because the output row is used multiple
+    times if png_read_row is called with a display row parameter.) This
+    should reduce memory utilization by libpng significantly, but it has no
+    detectable effect on overall performance figures of the test programs;
+    these are probably dominated by memory allocations for the whole image
+    within the test programs.
 
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CHANGES

@@ -5271,6 +5271,39 @@ Version 1.7.0beta69 [November 23, 2015]
     by flaviommedeiros).
   Fixed bug recently introduced in png_set_PLTE() that uses png_ptr
     not info_ptr.
+  Added pngvalid --transform --interlace test. This increases code
+    coverage by generating test cases with smaller length rows as a
+    result of the interlacing.  Without this packswap handling was
+    incompletely tested.
+  Fixed NO_WRITE_INTERLACE in pngvalid.c.  The support for writing
+    interlaced images directly from libpng 1.7 was unintentionally
+    disabled (INTERLACE_LAST was defined incorrectly, excluding the
+    interlaced images).  This obscured the fact that the transform and
+    error test case generators lacked the support for writing interlaced
+    images from libpng.
+  Transform rewrite: perform transforms in small chunks.  The intent
+    of this change is to reduce the memory footprint during transform
+    sequences by performing transforms in fixed (small) sized blocks of
+    pixels.  The change is incomplete; the filter code still works
+    row-by-row, so the whole tranform also works row-by-row. The intent
+    is to fix this so that everything works in small(ish) chunks.
+    At present the change has no discernable effect on pngvalid --speed
+    or pngstest with (e.g.) rgb-8-1.8.png; user time and (minor) page
+    faults are the same in old and new versions.  The same applies to
+    real-world 15MP PNG images; even on these the presence of the filter
+    code causes a cyclical progress through memory which will interfere
+    with any caching otherwise possible (useful word, 'otherwise'.) 
+  Read row buffer changes.  The read code now allocates one row buffer
+    of the size of the input PNG row and, only if required, one buffer of
+    the size of the output.  The output buffer is required for the
+    progressive reader (always) and for the sequential reader if libpng
+    is de-interlacing an image (because the output row is used multiple
+    times if png_read_row is called with a display row parameter.) This
+    should reduce memory utilization by libpng significantly, but it has no
+    detectable effect on overall performance figures of the test programs;
+    these are probably dominated by memory allocations for the whole image
+    within the test programs.
+
    
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png.c

@@ -711,13 +711,13 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.7.0beta69 - November 22, 2015" PNG_STRING_NEWLINE \
+     "libpng version 1.7.0beta69 - November 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 1.7.0beta69 - November 22, 2015\
+      return "libpng version 1.7.0beta69 - November 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.";

png.h

@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.7.0beta69, November 13, 2015
+ * libpng version 1.7.0beta69, November 23, 2015
  *
  * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -12,7 +12,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.7.0beta69, November 13, 2015:
+ *   libpng versions 0.97, January 1998, through 1.7.0beta69, November 23, 2015:
  *     Glenn Randers-Pehrson.
  *   See also "Contributing Authors", below.
  */
@@ -25,7 +25,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.0.7, July 1, 2000, through 1.7.0beta69, November 13, 2015, are
+ * libpng versions 1.0.7, July 1, 2000, through 1.7.0beta69, November 23, 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
@@ -218,7 +218,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    November 13, 2015
+ *    November 23, 2015
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -288,7 +288,7 @@
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.7.0beta69"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.7.0beta69 - November 13, 2015\n"
+     " libpng version 1.7.0beta69 - November 23, 2015\n"
 
 #define PNG_LIBPNG_VER_SONUM   17
 #define PNG_LIBPNG_VER_DLLNUM  17

pngconf.h

@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.7.0beta69, November 13, 2015
+ * libpng version 1.7.0beta69, November 23, 2015
  *
  * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)

scripts/pnglibconf.dfa

@@ -958,7 +958,7 @@ option WRITE_PNG requires WRITE WRITE_TRANSFORMS enables INFO_IMAGE
 #    Disabled by -DPNG_NO_CHECK_FOR_INVALID_INDEX
 #
 # 2) {READ,WRITE}_GET_PALETTE_MAX: returns the largest pixel value in a
-#    color mapped PNG.  Disbaled by -DPNG_NO_GET_PALETTE_MAX
+#    color mapped PNG.  Disabled by -DPNG_NO_GET_PALETTE_MAX
 #
 # All of this stuff can be removed by "option PALETTE_MAX off" but using
 # -DPNG_NO_ defines on the command line just sets the relevant option to

scripts/pnglibconf.h.prebuilt

@@ -2,7 +2,7 @@
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.7.0beta69 - November 13, 2015 */
+/* Libpng version 1.7.0beta69 - November 23, 2015 */
 
 /* Copyright (c) 1998-2015 Glenn Randers-Pehrson */
 
@@ -136,6 +136,7 @@
 #define PNG_WRITE_FILTER_SUPPORTED
 #define PNG_WRITE_FLUSH_SUPPORTED
 #define PNG_WRITE_GET_PALETTE_MAX_SUPPORTED
+#define PNG_WRITE_INTERLACE_SUPPORTED
 #define PNG_WRITE_INTERLACING_SUPPORTED
 #define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
 #define PNG_WRITE_INVERT_ALPHA_SUPPORTED