[libpng16] Catch up with some recent changes that did not get merged.

png.h

@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.7beta01 - September 16, 2013
+ * libpng version 1.6.7beta01 - September 30, 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.)
@@ -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 1.6.7beta01 - September 16, 2013: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.7beta01 - September 30, 2013: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -215,7 +215,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.7beta01, September 16, 2013, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.6.7beta01, September 30, 2013, are
  * Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -327,7 +327,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    September 16, 2013
+ *    September 30, 2013
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -395,7 +395,7 @@
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.6.7beta01"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.7beta01 - September 16, 2013\n"
+     " libpng version 1.6.7beta01 - September 30, 2013\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -721,7 +721,8 @@ typedef png_time * png_timep;
 typedef const png_time * png_const_timep;
 typedef png_time * * png_timepp;
 
-#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
+   defined(PNG_USER_CHUNKS_SUPPORTED)
 /* png_unknown_chunk is a structure to hold queued chunks for which there is
  * no specific support.  The idea is that we can use this to queue
  * up private chunks for output even though the library doesn't actually

pngrutil.c

@@ -2766,6 +2766,7 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
 
    png_debug(1, "in png_handle_unknown");
 
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
    /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
     * the bug which meant that setting a non-default behavior for a specific
     * chunk would be ignored (the default was always used unless a user
@@ -2778,14 +2779,15 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
     * function.
     */
 #  ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   keep = PNG_HANDLE_CHUNK_AS_DEFAULT;
+#     ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+         keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
+#     endif
 #  endif
 
    /* One of the following methods will read the chunk or skip it (at least one
     * of these is always defined because this is the only way to switch on
     * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
     */
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
 #  ifdef PNG_READ_USER_CHUNKS_SUPPORTED
       /* The user callback takes precedence over the chunk keep value, but the
        * keep value is still required to validate a save of a critical chunk.
@@ -2893,7 +2895,7 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
 
          png_crc_finish(png_ptr, length);
       }
-#  endif /* PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED */
+#  endif
 
 #  ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
       /* Now store the chunk in the chunk list if appropriate, and if the limits
@@ -2932,9 +2934,8 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
          }
 #     endif
       }
-#  else /* no store support! */
+#  else /* no store support: the chunk must be handled by the user callback */
       PNG_UNUSED(info_ptr)
-#     error untested code (reading unknown chunks with no store support)
 #  endif
 
    /* Regardless of the error handling below the cached data (if any) can be

pngtest.c

@@ -1391,11 +1391,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
-   png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
+#  ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-#endif
+      png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
-#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#  endif
-   png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#  ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+      png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#  endif
 #endif
 
    pngtest_debug("Reading and writing end_info data");

scripts/pnglibconf.dfa

@@ -753,6 +753,13 @@ option SAVE_UNKNOWN_CHUNKS enables READ_UNKNOWN_CHUNKS, STORE_UNKNOWN_CHUNKS
 # chunks, the callback can either handle the chunk entirely itself or request
 # that libpng store the chunk for later retrieval via png_get_unknown_chunks.
 #
+# NOTE: If STORE_UNKNOWN_CHUNKS is not enabled (which is the default if
+# both SAVE_UNKNOWN_CHUNKS and WRITE_UNKNOWN_CHUNKS are disabled) then a
+# 0 result from the callback will be ignored because no support for saving
+# unknown chunks has been compiled in.  The normal symptom is that your app
+# fails to compile because png_get_unknown_chunks is no longer defined in png.h.
+# If you encounter this issue simply enable STORE_UNKNOWN_CHUNKS in your build.
+#
 # Note that there is no 'WRITE_USER_CHUNKS' so the USER_CHUNKS option is always
 # the same as READ_USER_CHUNKS at present
 option READ_USER_CHUNKS requires READ, UNKNOWN_CHUNKS