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[libpng16] Revised png_set_keep_unknown_chunks() so num_chunks < 0 means

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ignore all unknown chunks and all known chunks except for IHDR, PLTE, tRNS,
IDAT, and IEND.  Previously it only meant ignore all unknown chunks, the
same as num_chunks == 0. Revised png_image_skip_unused_chunks() to
provide a list of chunks to be processed instead of a list of chunks to
ignore.  Revised contrib/gregbook/readpng2.c accordingly.
This commit is contained in:
Glenn Randers-Pehrson
2012-06-16 13:26:28 -05:00
parent 0546e4e579
commit 96b917056d
8 changed files with 144 additions and 93 deletions
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42
png.h
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@@ -1,7 +1,7 @@
/* png.h - header file for PNG reference library
*
* libpng version 1.6.0beta25 - June 12, 2012
* libpng version 1.6.0beta25 - June 16, 2012
* Copyright (c) 1998-2012 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 1.6.0beta25 - June 12, 2012: Glenn
* libpng versions 0.97, January 1998, through 1.6.0beta25 - June 16, 2012: Glenn
* See also "Contributing Authors", below.
*
* Note about libpng version numbers:
@@ -198,7 +198,7 @@
*
* This code is released under the libpng license.
*
* libpng versions 1.2.6, August 15, 2004, through 1.6.0beta25, June 12, 2012, are
* libpng versions 1.2.6, August 15, 2004, through 1.6.0beta25, June 16, 2012, are
* Copyright (c) 2004, 2006-2012 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:
@@ -310,7 +310,7 @@
* Y2K compliance in libpng:
* =========================
*
* June 12, 2012
* June 16, 2012
*
* Since the PNG Development group is an ad-hoc body, we can't make
* an official declaration.
@@ -320,14 +320,15 @@
* earlier versions were also Y2K compliant.
*
* Libpng only has two year fields. One is a 2-byte unsigned integer
* that will hold years up to 65535. The other holds the date in text
* format, and will hold years up to 9999.
* that will hold years up to 65535. The other, which is deprecated,
* holds the date in text format, and will hold years up to 9999.
*
* The integer is
* "png_uint_16 year" in png_time_struct.
*
* The string is
* "png_char time_buffer" in png_struct
* "char time_buffer[29]" in png_struct. This is no longer used
* in libpng-1.6.x and will be removed from libpng-1.7.0.
*
* There are seven time-related functions:
* png.c: png_convert_to_rfc_1123_buffer() in png.c
@@ -377,7 +378,7 @@
/* Version information for png.h - this should match the version in png.c */
#define PNG_LIBPNG_VER_STRING "1.6.0beta25"
#define PNG_HEADER_VERSION_STRING \
" libpng version 1.6.0beta25 - June 12, 2012\n"
" libpng version 1.6.0beta25 - June 16, 2012\n"
#define PNG_LIBPNG_VER_SONUM 16
#define PNG_LIBPNG_VER_DLLNUM 16
@@ -2318,15 +2319,22 @@ PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
/* Provide a list of chunks and how they are to be handled, if the built-in
handling or default unknown chunk handling is not desired. Any chunks not
listed will be handled in the default manner. The IHDR and IEND chunks
must not be listed. Because this turns off the default handling for chunks
that would otherwise be recognized the behavior of libpng transformations may
well become incorrect!
keep = 0: PNG_HANDLE_CHUNK_AS_DEFAULT: follow default behavior
= 1: PNG_HANDLE_CHUNK_NEVER: do not keep
= 2: PNG_HANDLE_CHUNK_IF_SAFE: keep only if safe-to-copy
= 3: PNG_HANDLE_CHUNK_ALWAYS: keep even if unsafe-to-copy
* handling or default unknown chunk handling is not desired. Any chunks not
* listed will be handled in the default manner. The IHDR and IEND chunks
* must not be listed. Because this turns off the default handling for chunks
* that would otherwise be recognized the behavior of libpng transformations may
* well become incorrect!
* keep = 0: PNG_HANDLE_CHUNK_AS_DEFAULT: follow default behavior
* = 1: PNG_HANDLE_CHUNK_NEVER: do not keep
* = 2: PNG_HANDLE_CHUNK_IF_SAFE: keep only if safe-to-copy
* = 3: PNG_HANDLE_CHUNK_ALWAYS: keep even if unsafe-to-copy
* If num_chunks is 0, then the "keep" parameter specifies the default
* manner for handling unknown chunks. If num_chunks is positive, then
* the "keep" parameter specifies the manner for handling only those chunks
* appearing in the chunk_list array. If it is negative, then the "keep"
* parameter specifies the manner for handling all unknown chunks plus
* all chunks recognized by libpng except for the IHDR, PLTE, tRNS, IDAT,
* and IEND chunks.
*/
PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
int keep, png_const_bytep chunk_list, int num_chunks));