[libpng16] Imported from libpng-1.6.18beta01.tar

have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
bug report by Andrew Church).

ANNOUNCE

@@ -1,67 +1,37 @@
-Libpng 1.6.17 - March 26, 2015
+Libpng 1.6.18beta01 - April 1, 2015
 
-This is a public release of libpng, intended for use in production codes.
+This is not intended to be a public release.  It will be replaced
+within a few weeks by a public version or by another test version.
 
 Files available for download:
 
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   libpng-1.6.17.tar.xz (LZMA-compressed, recommended)
-   libpng-1.6.17.tar.gz
+   1.6.18beta01.tar.xz (LZMA-compressed, recommended)
+   1.6.18beta01.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lpng1617.7z  (LZMA-compressed, recommended)
-   lpng1617.zip
+   lp1618b01.7z  (LZMA-compressed, recommended)
+   lp1618b01.zip
 
 Other information:
 
-   libpng-1.6.17-README.txt
-   libpng-1.6.17-LICENSE.txt
-   libpng-1.6.17-*.asc (armored detached GPG signatures)
+   1.6.18beta01-README.txt
+   1.6.18beta01-LICENSE.txt
+   libpng-1.6.18beta01-*.asc (armored detached GPG signatures)
 
-Changes since the last public release (1.6.16):
+Changes since the last public release (1.6.17):
 
-  Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h
-  Corrected the width limit calculation in png_check_IHDR().
-  Removed user limits from pngfix. Also pass NULL pointers to
-    png_read_row to skip the unnecessary row de-interlace stuff.
-  Added testing of png_set_packing() to pngvalid.c
-  Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
-  Implement previously untested cases of libpng transforms in pngvalid.c
-  Fixed byte order in 2-byte filler, in png_do_read_filler().
-  Made the check for out-of-range values in png_set_tRNS() detect
-    values that are exactly 2^bit_depth, and work on 16-bit platforms.
-  Merged some parts of libpng-1.6.17beta01 and libpng-1.7.0beta47.
-  Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and
-    pngset.c to avoid warnings about dead code.
-  Do not build png_product2() when it is unused.
-  Display user limits in the output from pngtest.
-  Eliminated the PNG_SAFE_LIMITS macro and restored the 1-million-column
-    and 1-million-row default limits in pnglibconf.dfa, that can be reset
-    by the user at build time or run time.  This provides a more robust
-    defense against DOS and as-yet undiscovered overflows.
-  Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
-  Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
-  Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
-  Moved png_set_filter() prototype into a PNG_WRITE_SUPPORTED block
-    of png.h.
-  Avoid runtime checks when converting integer to png_byte with
-    Visual Studio (Sergey Kosarevsky)
-  Removed some comments that the configure script did not handle
-    properly from scripts/pnglibconf.dfa and pnglibconf.h.prebuilt.
-  Free the unknown_chunks structure even when it contains no data.
-  Updated CMakeLists.txt to add OSX framework, change YES/NO to ON/OFF
-    for consistency, and remove some useless tests (Alexey Petruchik).
-  Remove pnglibconf.h, pnglibconf.c, pnglibconf.pre, pnglibconf.dfn,
-    and pnglibconf.out instead of pnglibconf.* in "make clean" (Cosmin).
-  Fixed simplified 8-bit-linear to sRGB alpha. The calculated alpha
-    value was wrong.  It's not clear if this affected the final stored
-    value; in the obvious code path the upper and lower 8-bits of the
-    alpha value were identical and the alpha was truncated to 8-bits
-    rather than dividing by 257 (John Bowler).
+Version 1.6.18beta01 [April 1, 2015]
+  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
+    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+    bug report by Andrew Church).
+  Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c.  This
+    fixes some arithmetic errors that caused some tests to fail on
+    some 32-bit platforms.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -5205,6 +5205,14 @@ Version 1.6.17rc06 [March 23, 2015]
 Version 1.6.17 [March 26, 2015]
   No changes.
 
+Version 1.6.18beta01 [April 1, 2015]
+  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
+    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+    bug report by Andrew Church).
+  Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c.  This
+    fixes some arithmetic errors that caused some tests to fail on
+    some 32-bit platforms.
+
 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

@@ -16,7 +16,7 @@ enable_testing()
 
 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 6)
-set(PNGLIB_RELEASE 17)
+set(PNGLIB_RELEASE 18)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
@@ -261,7 +261,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.17
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.18beta01
     VERSION 16.${PNGLIB_RELEASE}.0
     SOVERSION 16
     CLEAN_DIRECT_OUTPUT 1)

LICENSE

@@ -10,7 +10,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.17, March 26, 2015, are
+libpng versions 1.2.6, August 15, 2004, through 1.6.18beta01, April 1, 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
-March 26, 2015
+April 1, 2015

README

@@ -1,4 +1,4 @@
-README for libpng version 1.6.17 - March 26, 2015 (shared library 16.0)
+README for libpng version 1.6.18beta01 - April 1, 2015 (shared library 16.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.

autogen.sh

@@ -73,8 +73,9 @@ done
 # present bad things are happening.
 #
 # The autotools generated files:
-libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in\
-   config.sub configure depcomp install-sh ltmain.sh missing test-driver"
+libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in
+   config.h.in~ config.sub configure depcomp install-sh ltmain.sh missing\
+   test-driver"
 #
 # Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
 # versions than those required by configure.ac):

configure.ac

@@ -18,7 +18,7 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.17],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.18beta01],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -39,10 +39,10 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
 
-PNGLIB_VERSION=1.6.17
+PNGLIB_VERSION=1.6.18beta01
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=17
+PNGLIB_RELEASE=18
 
 dnl End of version number stuff
 

contrib/libtests/pngvalid.c

@@ -1,7 +1,7 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Last changed in libpng 1.6.17 [(PENDING RELEASE)]
  * Copyright (c) 2014-2015 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
@@ -258,7 +258,7 @@ make_four_random_bytes(png_uint_32* seed, png_bytep bytes)
    make_random_bytes(seed, bytes, 4);
 }
 
-#ifdef PNG_READ_SUPPORTED
+#if defined PNG_READ_SUPPORTED || defined PNG_WRITE_tRNS_SUPPORTED
 static void
 randomize(void *pv, size_t size)
 {
@@ -267,7 +267,9 @@ randomize(void *pv, size_t size)
 }
 
 #define RANDOMIZE(this) randomize(&(this), sizeof (this))
+#endif /* READ || WRITE_tRNS */
 
+#ifdef PNG_READ_SUPPORTED
 static unsigned int
 random_mod(unsigned int max)
 {
@@ -295,7 +297,8 @@ random_choice(void)
 /* A numeric ID based on PNG file characteristics.  The 'do_interlace' field
  * simply records whether pngvalid did the interlace itself or whether it
  * was done by libpng.  Width and height must be less than 256.  'palette' is an
- * index of the palette to use for formats with a palette (0 otherwise.)
+ * index of the palette to use for formats with a palette otherwise a boolean
+ * indicating if a tRNS chunk was generated.
  */
 #define FILEID(col, depth, palette, interlace, width, height, do_interlace) \
    ((png_uint_32)((col) + ((depth)<<3) + ((palette)<<8) + ((interlace)<<13) + \
@@ -316,12 +319,16 @@ standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type,
     png_uint_32 w, png_uint_32 h, int do_interlace)
 {
    pos = safecat(buffer, bufsize, pos, colour_types[colour_type]);
-   if (npalette > 0)
+   if (colour_type == 3) /* must have a palette */
    {
       pos = safecat(buffer, bufsize, pos, "[");
       pos = safecatn(buffer, bufsize, pos, npalette);
       pos = safecat(buffer, bufsize, pos, "]");
    }
+
+   else if (npalette != 0)
+      pos = safecat(buffer, bufsize, pos, "+tRNS");
+
    pos = safecat(buffer, bufsize, pos, " ");
    pos = safecatn(buffer, bufsize, pos, bit_depth);
    pos = safecat(buffer, bufsize, pos, " bit");
@@ -378,25 +385,32 @@ standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id)
 
 static int
 next_format(png_bytep colour_type, png_bytep bit_depth,
-   unsigned int* palette_number, int no_low_depth_gray)
+   unsigned int* palette_number, int low_depth_gray, int tRNS)
 {
    if (*bit_depth == 0)
    {
       *colour_type = 0;
-      if (no_low_depth_gray)
-         *bit_depth = 8;
-      else
+      if (low_depth_gray)
          *bit_depth = 1;
+      else
+         *bit_depth = 8;
       *palette_number = 0;
       return 1;
    }
 
-   if (*colour_type == 3)
+   if  (*colour_type < 4/*no alpha channel*/)
    {
-      /* Add multiple palettes for colour type 3. */
-      if (++*palette_number < PALETTE_COUNT(*bit_depth))
+      /* Add multiple palettes for colour type 3, one image with tRNS
+       * and one without for other non-alpha formats:
+       */
+      unsigned int pn = ++*palette_number;
+      png_byte ct = *colour_type;
+
+      if (((ct == 0/*GRAY*/ || ct/*RGB*/ == 2) && tRNS && pn < 2) ||
+          (ct == 3/*PALETTE*/ && pn < PALETTE_COUNT(*bit_depth)))
          return 1;
 
+      /* No: next bit depth */
       *palette_number = 0;
    }
 
@@ -1959,6 +1973,7 @@ typedef struct png_modifier
 
    /* Run tests on reading with a combination of transforms, */
    unsigned int             test_transform :1;
+   unsigned int             test_tRNS :1; /* Includes tRNS images */
 
    /* When to use the use_input_precision option, this controls the gamma
     * validation code checks.  If set any value that is within the transformed
@@ -1990,6 +2005,16 @@ typedef struct png_modifier
    unsigned int             test_gamma_expand16 :1;
    unsigned int             test_exhaustive :1;
 
+   /* Whether or not to run the low-bit-depth grayscale tests.  This fail on
+    * gamma images in some cases because of gross inaccuracies in the grayscale
+    * gamma handling for low bit depth.
+    */
+   unsigned int             test_lbg :1;
+   unsigned int             test_lbg_gamma_threshold :1;
+   unsigned int             test_lbg_gamma_transform :1;
+   unsigned int             test_lbg_gamma_sbit :1;
+   unsigned int             test_lbg_gamma_composition :1;
+
    unsigned int             log :1;   /* Log max error */
 
    /* Buffer information, the buffer size limits the size of the chunks that can
@@ -2042,6 +2067,11 @@ modifier_init(png_modifier *pm)
    pm->test_standard = 0;
    pm->test_size = 0;
    pm->test_transform = 0;
+#  ifdef PNG_WRITE_tRNS_SUPPORTED
+      pm->test_tRNS = 1;
+#  else
+      pm->test_tRNS = 0;
+#  endif
    pm->use_input_precision = 0;
    pm->use_input_precision_sbit = 0;
    pm->use_input_precision_16to8 = 0;
@@ -2054,6 +2084,11 @@ modifier_init(png_modifier *pm)
    pm->test_gamma_background = 0;
    pm->test_gamma_alpha_mode = 0;
    pm->test_gamma_expand16 = 0;
+   pm->test_lbg = 1;
+   pm->test_lbg_gamma_threshold = 1;
+   pm->test_lbg_gamma_transform = 1;
+   pm->test_lbg_gamma_sbit = 1;
+   pm->test_lbg_gamma_composition = 1;
    pm->test_exhaustive = 0;
    pm->log = 0;
 
@@ -3192,6 +3227,45 @@ init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette,
    }
 }
 
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+static void
+set_random_tRNS(png_structp pp, png_infop pi, PNG_CONST png_byte colour_type,
+   PNG_CONST int bit_depth)
+{
+   /* To make this useful the tRNS color needs to match at least one pixel.
+    * Random values are fine for gray, including the 16-bit case where we know
+    * that the test image contains all the gray values.  For RGB we need more
+    * method as only 65536 different RGB values are generated.
+    */
+   png_color_16 tRNS;
+   const png_uint_16 mask = (png_uint_16)((1U << bit_depth)-1);
+
+   RANDOMIZE(tRNS);
+
+   if (colour_type & 2/*RGB*/)
+   {
+      if (bit_depth == 8)
+      {
+         tRNS.blue = tRNS.red ^ tRNS.green;
+         tRNS.red &= mask;
+         tRNS.green &= mask;
+         tRNS.blue &= mask;
+      }
+
+      else /* bit_depth == 16 */
+      {
+         tRNS.green = (png_uint_16)(tRNS.red * 257);
+         tRNS.blue = (png_uint_16)(tRNS.green * 17);
+      }
+   }
+
+   else
+      tRNS.gray &= mask;
+
+   png_set_tRNS(pp, pi, NULL, 0, &tRNS);
+}
+#endif
+
 /* The number of passes is related to the interlace type. There was no libpng
  * API to determine this prior to 1.5, so we need an inquiry function:
  */
@@ -3525,6 +3599,11 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
       if (colour_type == 3) /* palette */
          init_standard_palette(ps, pp, pi, 1U << bit_depth, 1/*do tRNS*/);
 
+#     ifdef PNG_WRITE_tRNS_SUPPORTED
+         else if (palette_number)
+            set_random_tRNS(pp, pi, colour_type, bit_depth);
+#     endif
+
       png_write_info(pp, pi);
 
       if (png_get_rowbytes(pp, pi) !=
@@ -3598,19 +3677,20 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
 }
 
 static void
-make_transform_images(png_store *ps)
+make_transform_images(png_modifier *pm)
 {
    png_byte colour_type = 0;
    png_byte bit_depth = 0;
    unsigned int palette_number = 0;
 
    /* This is in case of errors. */
-   safecat(ps->test, sizeof ps->test, 0, "make standard images");
+   safecat(pm->this.test, sizeof pm->this.test, 0, "make standard images");
 
    /* Use next_format to enumerate all the combinations we test, including
-    * generating multiple low bit depth palette images.
+    * generating multiple low bit depth palette images. Non-A images (palette
+    * and direct) are created with and without tRNS chunks.
     */
-   while (next_format(&colour_type, &bit_depth, &palette_number, 0))
+   while (next_format(&colour_type, &bit_depth, &palette_number, 1, 1))
    {
       int interlace_type;
 
@@ -3621,7 +3701,7 @@ make_transform_images(png_store *ps)
 
          standard_name(name, sizeof name, 0, colour_type, bit_depth,
             palette_number, interlace_type, 0, 0, 0);
-         make_transform_image(ps, colour_type, bit_depth, palette_number,
+         make_transform_image(&pm->this, colour_type, bit_depth, palette_number,
             interlace_type, name);
       }
    }
@@ -4287,6 +4367,7 @@ typedef struct standard_display
    size_t      cbRow;          /* Bytes in a row of the output image */
    int         do_interlace;   /* Do interlacing internally */
    int         is_transparent; /* Transparency information was present. */
+   int         has_tRNS;       /* color type GRAY or RGB with a tRNS chunk. */
    int         speed;          /* Doing a speed test */
    int         use_update_info;/* Call update_info, not start_image */
    struct
@@ -4619,14 +4700,14 @@ standard_info_part1(standard_display *dp, png_structp pp, png_infop pi)
          case 0:
             dp->transparent.red = dp->transparent.green = dp->transparent.blue =
                trans_color->gray;
-            dp->is_transparent = 1;
+            dp->has_tRNS = 1;
             break;
 
          case 2:
             dp->transparent.red = trans_color->red;
             dp->transparent.green = trans_color->green;
             dp->transparent.blue = trans_color->blue;
-            dp->is_transparent = 1;
+            dp->has_tRNS = 1;
             break;
 
          case 3:
@@ -5518,7 +5599,7 @@ image_pixel_add_alpha(image_pixel *this, PNG_CONST standard_display *display)
       if (this->colour_type == PNG_COLOR_TYPE_GRAY)
       {
          if (this->bit_depth < 8)
-            this->bit_depth = 8;
+            this->bit_depth = this->sample_depth = 8;
 
          if (this->have_tRNS)
          {
@@ -5553,9 +5634,11 @@ image_pixel_add_alpha(image_pixel *this, PNG_CONST standard_display *display)
                this->alphaf = 0;
             else
                this->alphaf = 1;
-
-            this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
          }
+         else
+            this->alphaf = 1;
+
+         this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
       }
 
       /* The error in the alpha is zero and the sBIT value comes from the
@@ -5848,8 +5931,9 @@ transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
    /* If png_set_filler is in action then fake the output color type to include
     * an alpha channel where appropriate.
     */
-   if (dp->output_bit_depth >= 8 && (dp->output_colour_type == PNG_COLOR_TYPE_RGB ||
-       dp->output_colour_type == PNG_COLOR_TYPE_GRAY) && dp->this.filler)
+   if (dp->output_bit_depth >= 8 &&
+       (dp->output_colour_type == PNG_COLOR_TYPE_RGB ||
+        dp->output_colour_type == PNG_COLOR_TYPE_GRAY) && dp->this.filler)
        dp->output_colour_type |= 4;
 
    /* Validate the combination of colour type and bit depth that we are getting
@@ -6372,6 +6456,13 @@ image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this,
    transform_display *that, png_structp pp, png_infop pi)
 {
    png_set_tRNS_to_alpha(pp);
+
+   /* If there was a tRNS chunk that would get expanded and add an alpha
+    * channel is_transparent must be updated:
+    */
+   if (that->this.has_tRNS)
+      that->this.is_transparent = 1;
+
    this->next->set(this->next, that, pp, pi);
 }
 
@@ -6430,6 +6521,7 @@ image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this,
     transform_display *that, png_structp pp, png_infop pi)
 {
    png_set_gray_to_rgb(pp);
+   /* NOTE: this doesn't result in tRNS expansion. */
    this->next->set(this->next, that, pp, pi);
 }
 
@@ -6489,6 +6581,10 @@ image_transform_png_set_expand_set(PNG_CONST image_transform *this,
     transform_display *that, png_structp pp, png_infop pi)
 {
    png_set_expand(pp);
+
+   if (that->this.has_tRNS)
+      that->this.is_transparent = 1;
+
    this->next->set(this->next, that, pp, pi);
 }
 
@@ -6539,6 +6635,7 @@ image_transform_png_set_expand_gray_1_2_4_to_8_set(
     png_infop pi)
 {
    png_set_expand_gray_1_2_4_to_8(pp);
+   /* NOTE: don't expect this to expand tRNS */
    this->next->set(this->next, that, pp, pi);
 }
 
@@ -6570,6 +6667,11 @@ image_transform_png_set_expand_16_set(PNG_CONST image_transform *this,
     transform_display *that, png_structp pp, png_infop pi)
 {
    png_set_expand_16(pp);
+
+   /* NOTE: at present libpng does SET_EXPAND as well, so tRNS is expanded. */
+   if (that->this.has_tRNS)
+      that->this.is_transparent = 1;
+
    this->next->set(this->next, that, pp, pi);
 }
 
@@ -6940,14 +7042,14 @@ image_transform_png_set_rgb_to_gray_ini(PNG_CONST image_transform *this,
           * When DIGITIZE is set because a pre-1.7 version of libpng is being
           * tested allow a bigger slack.
           *
-          * NOTE: this magic number was determined by experiment to be 1.25.
-          * There's no great merit to the value below, however it only affects
-          * the limit used for checking for internal calculation errors, not
-          * the actual limit imposed by pngvalid on the output errors.
+          * NOTE: this magic number was determined by experiment to be about
+          * 1.263.  There's no great merit to the value below, however it only
+          * affects the limit used for checking for internal calculation errors,
+          * not the actual limit imposed by pngvalid on the output errors.
           */
          that->pm->limit += pow(
 #        if DIGITIZE
-            1.25
+            1.3
 #        else
             1.0
 #        endif
@@ -7111,7 +7213,8 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
          const unsigned int sample_depth = that->sample_depth;
          const unsigned int calc_depth = (pm->assume_16_bit_calculations ? 16 :
             sample_depth);
-         const unsigned int gamma_depth = (sample_depth == 16 ? 16 :
+         const unsigned int gamma_depth = (sample_depth == 16 ?
+            PNG_MAX_GAMMA_8 :
             (pm->assume_16_bit_calculations ? PNG_MAX_GAMMA_8 : sample_depth));
          int isgray;
          double r, g, b;
@@ -7125,56 +7228,73 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
           * will be identical after this operation if there is only one
           * transform, feel free to delete the png_error checks on this below in
           * the future (this is just me trying to ensure it works!)
+          *
+          * Interval arithmetic is exact, but to implement it it must be
+          * possible to control the floating point implementation rounding mode.
+          * This cannot be done in ANSI-C, so instead I reduce the 'lo' values
+          * by DBL_EPSILON and increase the 'hi' values by the same.
           */
+#        define DD(v,d,r) (digitize(v*(1-DBL_EPSILON), d, r) * (1-DBL_EPSILON))
+#        define DU(v,d,r) (digitize(v*(1+DBL_EPSILON), d, r) * (1+DBL_EPSILON))
+
          r = rlo = rhi = that->redf;
          rlo -= that->rede;
-         rlo = digitize(rlo, calc_depth, 1/*round*/);
+         rlo = DD(rlo, calc_depth, 1/*round*/);
          rhi += that->rede;
-         rhi = digitize(rhi, calc_depth, 1/*round*/);
+         rhi = DU(rhi, calc_depth, 1/*round*/);
 
          g = glo = ghi = that->greenf;
          glo -= that->greene;
-         glo = digitize(glo, calc_depth, 1/*round*/);
+         glo = DD(glo, calc_depth, 1/*round*/);
          ghi += that->greene;
-         ghi = digitize(ghi, calc_depth, 1/*round*/);
+         ghi = DU(ghi, calc_depth, 1/*round*/);
 
          b = blo = bhi = that->bluef;
          blo -= that->bluee;
-         blo = digitize(blo, calc_depth, 1/*round*/);
+         blo = DD(blo, calc_depth, 1/*round*/);
          bhi += that->greene;
-         bhi = digitize(bhi, calc_depth, 1/*round*/);
+         bhi = DU(bhi, calc_depth, 1/*round*/);
 
          isgray = r==g && g==b;
 
          if (data.gamma != 1)
          {
             PNG_CONST double power = 1/data.gamma;
-            PNG_CONST double abse = calc_depth == 16 ? .5/65535 : .5/255;
+            PNG_CONST double abse = .5/(sample_depth == 16 ? 65535 : 255);
 
-            /* 'abse' is the absolute error permitted in linear calculations. It
-             * is used here to capture the error permitted in the handling
-             * (undoing) of the gamma encoding.  Once again digitization occurs
-             * to handle the upper and lower bounds of the values.  This is
-             * where the real errors are introduced.
+            /* If a gamma calculation is done it is done using lookup tables of
+             * precision gamma_depth, so the already digitized value above may
+             * need to be further digitized here.
              */
+            if (gamma_depth != calc_depth)
+            {
+               rlo = DD(rlo, gamma_depth, 0/*truncate*/);
+               rhi = DU(rhi, gamma_depth, 0/*truncate*/);
+               glo = DD(glo, gamma_depth, 0/*truncate*/);
+               ghi = DU(ghi, gamma_depth, 0/*truncate*/);
+               blo = DD(blo, gamma_depth, 0/*truncate*/);
+               bhi = DU(bhi, gamma_depth, 0/*truncate*/);
+            }
+
+            /* 'abse' is the error in the gamma table calculation itself. */
             r = pow(r, power);
-            rlo = digitize(pow(rlo, power)-abse, calc_depth, 1);
-            rhi = digitize(pow(rhi, power)+abse, calc_depth, 1);
+            rlo = DD(pow(rlo, power)-abse, calc_depth, 1);
+            rhi = DU(pow(rhi, power)+abse, calc_depth, 1);
 
             g = pow(g, power);
-            glo = digitize(pow(glo, power)-abse, calc_depth, 1);
-            ghi = digitize(pow(ghi, power)+abse, calc_depth, 1);
+            glo = DD(pow(glo, power)-abse, calc_depth, 1);
+            ghi = DU(pow(ghi, power)+abse, calc_depth, 1);
 
             b = pow(b, power);
-            blo = digitize(pow(blo, power)-abse, calc_depth, 1);
-            bhi = digitize(pow(bhi, power)+abse, calc_depth, 1);
+            blo = DD(pow(blo, power)-abse, calc_depth, 1);
+            bhi = DU(pow(bhi, power)+abse, calc_depth, 1);
          }
 
          /* Now calculate the actual gray values.  Although the error in the
           * coefficients depends on whether they were specified on the command
           * line (in which case truncation to 15 bits happened) or not (rounding
           * was used) the maxium error in an individual coefficient is always
-          * 1/32768, because even in the rounding case the requirement that
+          * 2/32768, because even in the rounding case the requirement that
           * coefficients add up to 32768 can cause a larger rounding error.
           *
           * The only time when rounding doesn't occur in 1.5.5 and later is when
@@ -7185,19 +7305,19 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
 
          {
             PNG_CONST int do_round = data.gamma != 1 || calc_depth == 16;
-            PNG_CONST double ce = 1. / 32768;
+            PNG_CONST double ce = 2. / 32768;
 
-            graylo = digitize(rlo * (data.red_coefficient-ce) +
+            graylo = DD(rlo * (data.red_coefficient-ce) +
                glo * (data.green_coefficient-ce) +
-               blo * (data.blue_coefficient-ce), gamma_depth, do_round);
-            if (graylo <= 0)
-               graylo = 0;
+               blo * (data.blue_coefficient-ce), calc_depth, do_round);
+            if (graylo > gray) /* always accept the right answer */
+               graylo = gray;
 
-            grayhi = digitize(rhi * (data.red_coefficient+ce) +
+            grayhi = DU(rhi * (data.red_coefficient+ce) +
                ghi * (data.green_coefficient+ce) +
-               bhi * (data.blue_coefficient+ce), gamma_depth, do_round);
-            if (grayhi >= 1)
-               grayhi = 1;
+               bhi * (data.blue_coefficient+ce), calc_depth, do_round);
+            if (grayhi < gray)
+               grayhi = gray;
          }
 
          /* And invert the gamma. */
@@ -7205,11 +7325,25 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
          {
             PNG_CONST double power = data.gamma;
 
+            /* And this happens yet again, shifting the values once more. */
+            if (gamma_depth != sample_depth)
+            {
+               rlo = DD(rlo, gamma_depth, 0/*truncate*/);
+               rhi = DU(rhi, gamma_depth, 0/*truncate*/);
+               glo = DD(glo, gamma_depth, 0/*truncate*/);
+               ghi = DU(ghi, gamma_depth, 0/*truncate*/);
+               blo = DD(blo, gamma_depth, 0/*truncate*/);
+               bhi = DU(bhi, gamma_depth, 0/*truncate*/);
+            }
+
             gray = pow(gray, power);
-            graylo = digitize(pow(graylo, power), sample_depth, 1);
-            grayhi = digitize(pow(grayhi, power), sample_depth, 1);
+            graylo = DD(pow(graylo, power), sample_depth, 1);
+            grayhi = DU(pow(grayhi, power), sample_depth, 1);
          }
 
+#        undef DD
+#        undef DU
+
          /* Now the error can be calculated.
           *
           * If r==g==b because there is no overall gamma correction libpng
@@ -7260,16 +7394,28 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
          {
             /* There is no need to do the conversions to and from linear space,
              * so the calculation should be a lot more accurate.  There is a
-             * built in 1/32768 error in the coefficients because they only have
-             * 15 bits and are adjusted to make sure they add up to 32768, so
-             * the result may have an additional error up to 1/32768.  (Note
-             * that adding the 1/32768 here avoids needing to increase the
-             * global error limits to take this into account.)
+             * built in error in the coefficients because they only have 15 bits
+             * and are adjusted to make sure they add up to 32768.  This
+             * involves a integer calculation with truncation of the form:
+             *
+             *     ((int)(coefficient * 100000) * 32768)/100000
+             *
+             * This is done to the red and green coefficients (the ones
+             * provided to the API) then blue is calculated from them so the
+             * result adds up to 32768.  In the worst case this can result in
+             * a -1 error in red and green and a +2 error in blue.  Consequently
+             * the worst case in the calculation below is 2/32768 error.
+             *
+             * TODO: consider fixing this in libpng by rounding the calculation
+             * limiting the error to 1/32768.
+             *
+             * Handling this by adding 2/32768 here avoids needing to increase
+             * the global error limits to take this into account.)
              */
             gray = r * data.red_coefficient + g * data.green_coefficient +
                b * data.blue_coefficient;
             err = re * data.red_coefficient + ge * data.green_coefficient +
-               be * data.blue_coefficient + 1./32768 + gray * 5 * DBL_EPSILON;
+               be * data.blue_coefficient + 2./32768 + gray * 5 * DBL_EPSILON;
          }
 
          else
@@ -7304,7 +7450,7 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
              * previously added input quantization error at this point.
              */
             gray = r * data.red_coefficient + g * data.green_coefficient +
-               b * data.blue_coefficient - 1./32768 - out_qe;
+               b * data.blue_coefficient - 2./32768 - out_qe;
             if (gray <= 0)
                gray = 0;
             else
@@ -7314,7 +7460,7 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
             }
 
             grayhi = rhi * data.red_coefficient + ghi * data.green_coefficient +
-               bhi * data.blue_coefficient + 1./32768 + out_qe;
+               bhi * data.blue_coefficient + 2./32768 + out_qe;
             grayhi *= (1 + 6 * DBL_EPSILON);
             if (grayhi >= 1)
                grayhi = 1;
@@ -7429,6 +7575,9 @@ image_transform_png_set_background_set(PNG_CONST image_transform *this,
 
    else
    {
+      if (that->this.has_tRNS)
+         that->this.is_transparent = 1;
+
       bit_depth = that->this.bit_depth;
       expand = 1;
    }
@@ -7506,14 +7655,14 @@ image_transform_png_set_background_mod(PNG_CONST image_transform *this,
       /* Remove the alpha type and set the alpha (not in that order.) */
       that->alphaf = 1;
       that->alphae = 0;
-
-      if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
-         that->colour_type = PNG_COLOR_TYPE_RGB;
-      else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-         that->colour_type = PNG_COLOR_TYPE_GRAY;
-      /* PNG_COLOR_TYPE_PALETTE is not changed */
    }
 
+   if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      that->colour_type = PNG_COLOR_TYPE_RGB;
+   else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      that->colour_type = PNG_COLOR_TYPE_GRAY;
+   /* PNG_COLOR_TYPE_PALETTE is not changed */
+
    this->next->mod(this->next, that, pp, display);
 }
 
@@ -8301,7 +8450,8 @@ perform_transform_test(png_modifier *pm)
    png_byte bit_depth = 0;
    unsigned int palette_number = 0;
 
-   while (next_format(&colour_type, &bit_depth, &palette_number, 0))
+   while (next_format(&colour_type, &bit_depth, &palette_number, pm->test_lbg,
+            pm->test_tRNS))
    {
       png_uint_32 counter = 0;
       size_t base_pos;
@@ -8604,7 +8754,9 @@ init_validate_info(validate_info *vi, gamma_display *dp, png_const_structp pp,
    vi->outlog = outlog(dp->pm, in_depth, out_depth);
 
    if ((dp->this.colour_type & PNG_COLOR_MASK_ALPHA) != 0 ||
-      (dp->this.colour_type == 3 && dp->this.is_transparent))
+      (dp->this.colour_type == 3 && dp->this.is_transparent) ||
+      ((dp->this.colour_type == 0 || dp->this.colour_type == 2) &&
+       dp->this.has_tRNS))
    {
       vi->do_background = dp->do_background;
 
@@ -8634,7 +8786,7 @@ init_validate_info(validate_info *vi, gamma_display *dp, png_const_structp pp,
          vi->background_blue = b;
       }
    }
-   else
+   else /* Do not expect any background processing */
       vi->do_background = 0;
 
    if (vi->do_background == 0)
@@ -9350,6 +9502,7 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
    png_uint_32 y;
    PNG_CONST store_palette_entry *in_palette = dp->this.palette;
    PNG_CONST int in_is_transparent = dp->this.is_transparent;
+   int process_tRNS;
    int out_npalette = -1;
    int out_is_transparent = 0; /* Just refers to the palette case */
    store_palette out_palette;
@@ -9365,6 +9518,7 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
 
    processing = (vi.gamma_correction > 0 && !dp->threshold_test)
       || in_bd != out_bd || in_ct != out_ct || vi.do_background;
+   process_tRNS = dp->this.has_tRNS && vi.do_background;
 
    /* TODO: FIX THIS: MAJOR BUG!  If the transformations all happen inside
     * the palette there is no way of finding out, because libpng fails to
@@ -9403,8 +9557,8 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
             /* Handle input alpha - png_set_background will cause the output
              * alpha to disappear so there is nothing to check.
              */
-            if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 || (in_ct == 3 &&
-               in_is_transparent))
+            if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 ||
+                (in_ct == 3 && in_is_transparent))
             {
                PNG_CONST unsigned int input_alpha = in_ct == 3 ?
                   dp->this.palette[in_index].alpha :
@@ -9436,6 +9590,35 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
                }
             }
 
+            else if (process_tRNS)
+            {
+               /* alpha needs to be set appropriately for this pixel, it is
+                * currently 1 and needs to be 0 for an input pixel which matches
+                * the values in tRNS.
+                */
+               switch (in_ct)
+               {
+                  case 0: /* gray */
+                     if (sample(std, in_ct, in_bd, x, 0, 0, 0) ==
+                           dp->this.transparent.red)
+                        alpha = 0;
+                     break;
+
+                  case 2: /* RGB */
+                     if (sample(std, in_ct, in_bd, x, 0, 0, 0) ==
+                           dp->this.transparent.red &&
+                         sample(std, in_ct, in_bd, x, 1, 0, 0) ==
+                           dp->this.transparent.green &&
+                         sample(std, in_ct, in_bd, x, 2, 0, 0) ==
+                           dp->this.transparent.blue)
+                        alpha = 0;
+                     break;
+
+                  default:
+                     break;
+               }
+            }
+
             /* Handle grayscale or RGB components. */
             if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* grayscale */
                (void)gamma_component_validate("gray", &vi,
@@ -9545,7 +9728,7 @@ gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn,
 
       modification_reset(d.pm->modifications);
 
-      /* Get a png_struct for writing the image. */
+      /* Get a png_struct for reading the image. */
       pp = set_modifier_for_read(d.pm, &pi, d.this.id, name);
       standard_palette_init(&d.this);
 
@@ -9684,9 +9867,13 @@ perform_gamma_threshold_tests(png_modifier *pm)
    /* Don't test more than one instance of each palette - it's pointless, in
     * fact this test is somewhat excessive since libpng doesn't make this
     * decision based on colour type or bit depth!
+    *
+    * CHANGED: now test two palettes and, as a side effect, images with and
+    * without tRNS.
     */
-   while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/))
-      if (palette_number == 0)
+   while (next_format(&colour_type, &bit_depth, &palette_number,
+                      pm->test_lbg_gamma_threshold, pm->test_tRNS))
+      if (palette_number < 2)
    {
       double test_gamma = 1.0;
       while (test_gamma >= .4)
@@ -9746,7 +9933,8 @@ static void perform_gamma_transform_tests(png_modifier *pm)
    png_byte bit_depth = 0;
    unsigned int palette_number = 0;
 
-   while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/))
+   while (next_format(&colour_type, &bit_depth, &palette_number,
+                      pm->test_lbg_gamma_transform, pm->test_tRNS))
    {
       unsigned int i, j;
 
@@ -9776,7 +9964,8 @@ static void perform_gamma_sbit_tests(png_modifier *pm)
       png_byte colour_type = 0, bit_depth = 0;
       unsigned int npalette = 0;
 
-      while (next_format(&colour_type, &bit_depth, &npalette, 1/*gamma*/))
+      while (next_format(&colour_type, &bit_depth, &npalette,
+                         pm->test_lbg_gamma_sbit, pm->test_tRNS))
          if ((colour_type & PNG_COLOR_MASK_ALPHA) == 0 &&
             ((colour_type == 3 && sbit < 8) ||
             (colour_type != 3 && sbit < bit_depth)))
@@ -9967,8 +10156,17 @@ static void gamma_composition_test(png_modifier *pm,
    }
 
    background.index = 193; /* rgb(193,193,193) to detect errors */
+
    if (!(colour_type & PNG_COLOR_MASK_COLOR))
    {
+      /* Because, currently, png_set_background is always called with
+       * 'need_expand' false in this case and because the gamma test itself
+       * doesn't cause an expand to 8-bit for lower bit depths the colour must
+       * be reduced to the correct range.
+       */
+      if (bit_depth < 8)
+         background.gray &= (png_uint_16)((1U << bit_depth)-1);
+
       /* Grayscale input, we do not convert to RGB (TBD), so we must set the
        * background to gray - else libpng seems to fail.
        */
@@ -10017,9 +10215,18 @@ perform_gamma_composition_tests(png_modifier *pm, int do_background,
 
    /* Skip the non-alpha cases - there is no setting of a transparency colour at
     * present.
+    *
+    * TODO: incorrect; the palette case sets tRNS and, now RGB and gray do,
+    * however the palette case fails miserably so is commented out below.
     */
-   while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/))
-      if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0)
+   while (next_format(&colour_type, &bit_depth, &palette_number,
+                      pm->test_lbg_gamma_composition, pm->test_tRNS))
+      if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0
+#if 0 /* TODO: FIXME */
+          /*TODO: FIXME: this should work */
+          || colour_type == 3
+#endif
+          || (colour_type != 3 && palette_number != 0))
    {
       unsigned int i, j;
 
@@ -10751,6 +10958,18 @@ int main(int argc, char **argv)
    pm.ngammas = ARRAY_SIZE(gammas);
    pm.ngamma_tests = 0; /* default to off */
 
+   /* Low bit depth gray images don't do well in the gamma tests, until
+    * this is fixed turn them off for some gamma cases:
+    */
+#  ifdef PNG_WRITE_tRNS_SUPPORTED
+      pm.test_tRNS = 1;
+#  endif
+   pm.test_lbg = 0;
+   pm.test_lbg_gamma_threshold = 1;
+   pm.test_lbg_gamma_transform = 0/*PNG_LIBPNG_VER >= 10700*/;
+   pm.test_lbg_gamma_sbit = 1;
+   pm.test_lbg_gamma_composition = 0;
+
    /* And the test encodings */
    pm.encodings = test_encodings;
    pm.nencodings = ARRAY_SIZE(test_encodings);
@@ -10863,7 +11082,7 @@ int main(int argc, char **argv)
          pm.test_gamma_transform = 1;
          pm.test_gamma_sbit = 1;
          pm.test_gamma_scale16 = 1;
-         pm.test_gamma_background = 1;
+         pm.test_gamma_background = 1; /* composition */
          pm.test_gamma_alpha_mode = 1;
          }
 
@@ -10912,6 +11131,24 @@ int main(int argc, char **argv)
       else if (strcmp(*argv, "--noexpand16") == 0)
          pm.test_gamma_expand16 = 0;
 
+      else if (strcmp(*argv, "--low-depth-gray") == 0)
+         pm.test_lbg = pm.test_lbg_gamma_threshold =
+            pm.test_lbg_gamma_transform = pm.test_lbg_gamma_sbit =
+            pm.test_lbg_gamma_composition = 1;
+
+      else if (strcmp(*argv, "--nolow-depth-gray") == 0)
+         pm.test_lbg = pm.test_lbg_gamma_threshold =
+            pm.test_lbg_gamma_transform = pm.test_lbg_gamma_sbit =
+            pm.test_lbg_gamma_composition = 0;
+
+#     ifdef PNG_WRITE_tRNS_SUPPORTED
+         else if (strcmp(*argv, "--tRNS") == 0)
+            pm.test_tRNS = 1;
+#     endif
+
+      else if (strcmp(*argv, "--notRNS") == 0)
+         pm.test_tRNS = 0;
+
       else if (strcmp(*argv, "--more-gammas") == 0)
          pm.ngamma_tests = 3U;
 
@@ -11102,7 +11339,7 @@ int main(int argc, char **argv)
    Try
    {
       /* Make useful base images */
-      make_transform_images(&pm.this);
+      make_transform_images(&pm);
 
       /* Perform the standard and gamma tests. */
       if (pm.test_standard)

contrib/tools/pngfix.c

@@ -2,7 +2,7 @@
  *
  * Copyright (c) 2014-2015 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Last changed in libpng 1.6.17 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

libpng-manual.txt

@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.17 - March 26, 2015
+ libpng version 1.6.18beta01 - April 1, 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 1.6.17 - March 26, 2015
+ libpng versions 0.97, January 1998, through 1.6.18beta01 - April 1, 2015
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
@@ -5279,13 +5279,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 XVI. Y2K Compliance in libpng
 
-March 26, 2015
+April 1, 2015
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.17 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.18beta01 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 "March 26, 2015"
+.TH LIBPNG 3 "April 1, 2015"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.17
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.18beta01
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@@ -504,7 +504,7 @@ 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 1.6.17 - March 26, 2015
+ libpng version 1.6.18beta01 - April 1, 2015
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
@@ -515,7 +515,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.17 - March 26, 2015
+ libpng versions 0.97, January 1998, through 1.6.18beta01 - April 1, 2015
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
@@ -5783,13 +5783,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 .SH XVI. Y2K Compliance in libpng
 
-March 26, 2015
+April 1, 2015
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.17 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.18beta01 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
@@ -6044,6 +6044,7 @@ the first widely used release:
  1.6.17beta01-06     16    10617  16.so.16.17[.0]
  1.6.17rc01-06       16    10617  16.so.16.17[.0]
  1.6.17              16    10617  16.so.16.17[.0]
+ 1.6.18beta01        16    10618  16.so.16.18[.0]
 
 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@@ -6100,7 +6101,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.6.17 - March 26, 2015:
+Libpng version 1.6.18beta01 - April 1, 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).
 
@@ -6123,7 +6124,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.17, March 26, 2015, are
+libpng versions 1.2.6, August 15, 2004, through 1.6.18beta01, April 1, 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
@@ -6222,7 +6223,7 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-March 26, 2015
+April 1, 2015
 
 .\" end of man page
 

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "March 26, 2015"
+.TH LIBPNGPF 3 "April 1, 2015"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.17
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.18beta01
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "March 26, 2015"
+.TH PNG 5 "April 1, 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_6_17 Your_png_h_is_not_version_1_6_17;
+typedef png_libpng_version_1_6_18beta01 Your_png_h_is_not_version_1_6_18beta01;
 
 /* 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
@@ -766,13 +766,13 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.6.17 - March 26, 2015" PNG_STRING_NEWLINE \
+     "libpng version 1.6.18beta01 - April 1, 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 1.6.17 - March 26, 2015\
+      return "libpng version 1.6.18beta01 - April 1, 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 1.6.17, March 26, 2015
+ * libpng version 1.6.18beta01, April 1, 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 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.17, March 26, 2015: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.18beta01, April 1, 2015: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -216,6 +216,7 @@
  *    1.6.17beta01-06         16    10617  16.so.16.17[.0]
  *    1.6.17rc01-06           16    10617  16.so.16.17[.0]
  *    1.6.17                  16    10617  16.so.16.17[.0]
+ *    1.6.18beta01            16    10618  16.so.16.18[.0]
  *
  *   Henceforth the source version will match the shared-library major
  *   and minor numbers; the shared-library major version number will be
@@ -247,7 +248,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.17, March 26, 2015, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.6.18beta01, April 1, 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:
@@ -359,13 +360,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    March 26, 2015
+ *    April 1, 2015
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.6.17 are Y2K compliant.  It is my belief that
+ *    upward through 1.6.18beta01 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
@@ -427,9 +428,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.17"
+#define PNG_LIBPNG_VER_STRING "1.6.18beta01"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.17 - March 26, 2015\n"
+     " libpng version 1.6.18beta01 - April 1, 2015\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -437,13 +438,13 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 17
+#define PNG_LIBPNG_VER_RELEASE 18
 
 /* 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
+#define PNG_LIBPNG_VER_BUILD  01
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
@@ -460,7 +461,7 @@
 #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
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
 
 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  * We must not include leading zeros.
@@ -468,7 +469,7 @@
  * 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 10617 /* 1.6.17 */
+#define PNG_LIBPNG_VER 10618 /* 1.6.18 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -573,7 +574,7 @@ 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_6_17;
+typedef char* png_libpng_version_1_6_18beta01;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *

pngconf.h

@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.17, March 26, 2015
+ * libpng version 1.6.18beta01, (PENDING RELEASE)
  *
  * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)

pngrutil.c

@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Last changed in libpng 1.6.18 [(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.)
@@ -575,7 +575,7 @@ png_decompress_chunk(png_structrp png_ptr,
     */
    png_alloc_size_t limit = PNG_SIZE_MAX;
 
-# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+# ifdef PNG_SET_USER_LIMITS_SUPPORTED
    if (png_ptr->user_chunk_malloc_max > 0 &&
        png_ptr->user_chunk_malloc_max < limit)
       limit = png_ptr->user_chunk_malloc_max;
@@ -2715,7 +2715,7 @@ png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
       png_ptr->unknown_chunk.data = NULL;
    }
 
-#  ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+#  ifdef PNG_SET_USER_LIMITS_SUPPORTED
       if (png_ptr->user_chunk_malloc_max > 0 &&
           png_ptr->user_chunk_malloc_max < limit)
          limit = png_ptr->user_chunk_malloc_max;

pngtest.c

@@ -2028,4 +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_6_17 Your_png_h_is_not_version_1_6_17;
+typedef png_libpng_version_1_6_18beta01 Your_png_h_is_not_version_1_6_18beta01;

projects/vstudio/readme.txt

@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.6.17 - March 26, 2015
+libpng version 1.6.18beta01 - April 1, 2015
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 

projects/vstudio/zlib.props

@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.6.17 - March 26, 2015
+ * libpng version 1.6.18beta01 - April 1, 2015
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *

scripts/README.txt

@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.6.17 - March 26, 2015
+Makefiles for  libpng version 1.6.18beta01 - April 1, 2015
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng16.so.16.1.6.17)
+                       (gcc, creates libpng16.so.16.1.6.18beta01)
  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 libpng16.so.16.1.6.17)
+                       creates libpng16.so.16.1.6.18beta01)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng16.so.16.1.6.17)
+                       creates libpng16.so.16.1.6.18beta01)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng16.so.16.1.6.17)
+                       creates libpng16.so.16.1.6.18beta01)
  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 1.6.17"
+PNG_DFN ";Version 1.6.18beta01"
 
 #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=1.6.17
+version=1.6.18beta01
 prefix=""
 libdir=""
 libs=""

scripts/libpng.pc.in

@@ -5,6 +5,6 @@ includedir=@includedir@/libpng16
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.6.17
+Version: 1.6.18beta01
 Libs: -L${libdir} -lpng16
 Cflags: -I${includedir}

scripts/makefile.cegcc

@@ -23,7 +23,7 @@
 
 VERMAJ = 1
 VERMIN = 6
-VERMIC = 17
+VERMIC = 18
 VER = $(VERMAJ).$(VERMIN).$(VERMIC)
 NAME = libpng
 PACKAGE = $(NAME)-$(VER)

scripts/makefile.linux

@@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 17
+RELEASE = 18
 
 # Shared library names:
 LIBSO=$(LIBNAME).so

scripts/makefile.msys

@@ -18,7 +18,7 @@ exec_prefix=$(prefix)
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 17
+RELEASE = 18
 
 # Shared library names:
 LIBSO=$(LIBNAME).dll

scripts/makefile.ne12bsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng16
 
 LIB=	png16
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.6.17
+SHLIB_MINOR=	1.6.18beta01
 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=	16
-SHLIB_MINOR=	1.6.17
+SHLIB_MINOR=	1.6.18beta01
 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=	16
-SHLIB_MINOR=	1.6.17
+SHLIB_MINOR=	1.6.18beta01
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \

scripts/pnglibconf.h.prebuilt

@@ -1,8 +1,8 @@
-/* libpng 1.6.17 STANDARD API DEFINITION */
+/* libpng 1.6.18beta01 STANDARD API DEFINITION */
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.6.17 - March 26, 2015 */
+/* Libpng version 1.6.18beta01 - April 1, 2015 */
 
 /* Copyright (c) 1998-2014 Glenn Randers-Pehrson */
 
@@ -101,8 +101,6 @@
 #define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SEQUENTIAL_READ_SUPPORTED
 #define PNG_SETJMP_SUPPORTED
-#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
-#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
 #define PNG_SET_OPTION_SUPPORTED
 #define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SET_USER_LIMITS_SUPPORTED

scripts/symbols.def

@@ -1,4 +1,4 @@
-;Version 1.6.17
+;Version 1.6.18beta01
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng