[master] Imported from libpng-1.6.15.tar

ANNOUNCE

@@ -1,4 +1,4 @@
-Libpng 1.6.14 - October 23, 2014
+Libpng 1.6.15 - November 20, 2014
 
 This is a public release of libpng, intended for use in production codes.
 
@@ -7,52 +7,55 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   libpng-1.6.14.tar.xz (LZMA-compressed, recommended)
-   libpng-1.6.14.tar.gz
+   libpng-1.6.15.tar.xz (LZMA-compressed, recommended)
+   libpng-1.6.15.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lpng1614.7z  (LZMA-compressed, recommended)
-   lpng1614.zip
+   lpng1615.7z  (LZMA-compressed, recommended)
+   lpng1615.zip
 
 Other information:
 
-   libpng-1.6.14-README.txt
-   libpng-1.6.14-LICENSE.txt
-   libpng-1.6.14-*.asc (armored detached GPG signatures)
+   libpng-1.6.15-README.txt
+   libpng-1.6.15-LICENSE.txt
+   libpng-1.6.15-*.asc (armored detached GPG signatures)
 
-Changes since the last public release (1.6.13):
-  Guard usage of png_ptr->options with #ifdef PNG_SET_OPTION_SUPPORTED.
-  Do not build contrib/tools/pngfix.c when PNG_SETJMP_NOT_SUPPORTED,
-    to allow "make" to complete without setjmp support (bug report by
-    Claudio Fontana)
-  Add "#include <setjmp.h>" to contrib/tools/pngfix.c (John Bowler)
-  Use nanosleep() instead of usleep() in contrib/gregbook/rpng2-x.c
-    because usleep() is deprecated.
-  Define usleep() in contrib/gregbook/rpng2-x.c if not already defined
-    in unistd.h and nanosleep() is not available; fixes error introduced
-    in libpng-1.6.13.
-  Define FE_DIVBYZERO, FE_INVALID, and FE_OVERFLOW in pngvalid.c if not
-    already defined (bug report by "zootus at users.sourceforge.net").
-  Fixed incorrect handling of the iTXt compression flag in pngrutil.c
-    (bug report by Shunsaku Hirata).  Bug was introduced in libpng-1.6.0.
-  Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa
-  Removed unused "text_len" parameter from private function png_write_zTXt().
-  Conditionally compile some code in png_deflate_claim(), when
-    PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled.
-  Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL.
-  Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT"
-    to pnglibconf.dfa.
-  Removed "option READ_COMPRESSED_TEXT enables READ_TEXT" from pnglibconf.dfa,
-    to make it possible to configure a libpng that supports iCCP but not TEXT.
-  Removed "option WRITE_COMPRESSED_TEXT enables WRITE_TEXT" from pnglibconf.dfa
-  Only mark text chunks as written after successfully writing them.
-  Fixed some typos in comments.
-  Changed png_convert_to_rfc_1123() to png_convert_to_rfc_1123_buffer()
-    in the manual, to reflect the change made in libpng-1.6.0.
-  Updated README file to explain that direct access to the png_struct
-    and info_struct members has not been permitted since libpng-1.5.0.
+Changes since the last public release (1.6.14):
+  Changed "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
+  Simplified png_free_data().
+  Added missing "ptr = NULL" after some instances of png_free().
+  Made a one-line revision to configure.ac to support ARM on aarch64
+    (bug report by Marcin Juszkiewicz, fix by John Bowler).
+  Avoid out-of-bounds memory access in png_user_version_check().
+  Simplified and future-proofed png_user_version_check().
+  Fixed GCC unsigned int->float warnings. Various versions of GCC
+    seem to generate warnings when an unsigned value is implicitly
+    converted to double. This is probably a GCC bug but this change
+    avoids the issue by explicitly converting to (int) where safe.
+  Free all allocated memory in pngimage. The file buffer cache was left
+    allocated at the end of the program, harmless but it causes memory
+    leak reports from clang.
+  Fixed array size calculations to avoid warnings. At various points
+    in the code the number of elements in an array is calculated using
+    sizeof.  This generates a compile time constant of type (size_t) which
+    is then typically assigned to an (unsigned int) or (int). Some versions
+    of GCC on 64-bit systems warn about the apparent narrowing, even though
+    the same compiler does apparently generate the correct, in-range,
+    numeric constant.  This adds appropriate, safe, casts to make the
+    warnings go away.
+  Removed #ifdef PNG_16BIT_SUPPORTED/#endif around png_product2(); it is
+    needed by png_reciprocal2().
+  Added #ifdef PNG_16BIT_SUPPORTED/#endif around png_log16bit() and
+    png_do_swap().
+  Changed all "#endif /* PNG_FEATURE_SUPPORTED */" to "#endif /* FEATURE */"
+  The macros passed in the command line to Borland make were ignored if
+    similarly-named macros were already defined in makefiles. This behavior
+    is different from POSIX make and other make programs.  Surround the
+    macro definitions with ifndef guards (Cosmin).
+  Added "-D_CRT_SECURE_NO_WARNINGS" to CFLAGS in scripts/makefile.vcwin32.
+  Removed the obsolete $ARCH variable from scripts/makefile.darwin.
 
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