[libpng16] Revised png_set_keep_unknown_chunks() so num_chunks < 0 means
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.
diff --git a/ANNOUNCE b/ANNOUNCE
index 10a572b..2748641 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
-Libpng 1.6.0beta25 - June 12, 2012
+Libpng 1.6.0beta25 - June 16, 2012
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.
@@ -385,7 +385,13 @@
Version 1.6.0beta24 [June 7, 2012]
Don't check palette indexes if num_palette is 0 (as it can be in MNG files).
-Version 1.6.0beta25 [June 12, 2012]
+Version 1.6.0beta25 [June 16, 2012]
+ Revised png_set_keep_unknown_chunks() so num_chunks < 0 means 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.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit
diff --git a/CHANGES b/CHANGES
index 52a60a0..a08218d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4136,7 +4136,13 @@
Version 1.6.0beta24 [June 7, 2012]
Don't check palette indexes if num_palette is 0 (as it can be in MNG files).
-Version 1.6.0beta25 [June 12, 2012]
+Version 1.6.0beta25 [June 16, 2012]
+ Revised png_set_keep_unknown_chunks() so num_chunks < 0 means 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.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit
diff --git a/contrib/gregbook/readpng2.c b/contrib/gregbook/readpng2.c
index b9746b7..e179db7 100644
--- a/contrib/gregbook/readpng2.c
+++ b/contrib/gregbook/readpng2.c
@@ -136,29 +136,23 @@
* used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT,
* IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */
{
- /* These byte strings were copied from png.h. If a future libpng
- * version recognizes more chunks, add them to this list. If a
- * future version of readpng2.c recognizes more chunks, delete them
- * from this list. */
- static /* const */ png_byte chunks_to_ignore[] = {
- 99, 72, 82, 77, '\0', /* cHRM */
- 104, 73, 83, 84, '\0', /* hIST */
- 105, 67, 67, 80, '\0', /* iCCP */
- 105, 84, 88, 116, '\0', /* iTXt */
- 111, 70, 70, 115, '\0', /* oFFs */
- 112, 67, 65, 76, '\0', /* pCAL */
- 112, 72, 89, 115, '\0', /* pHYs */
- 115, 66, 73, 84, '\0', /* sBIT */
- 115, 67, 65, 76, '\0', /* sCAL */
- 115, 80, 76, 84, '\0', /* sPLT */
- 115, 84, 69, 82, '\0', /* sTER */
- 116, 69, 88, 116, '\0', /* tEXt */
- 116, 73, 77, 69, '\0', /* tIME */
- 122, 84, 88, 116, '\0' /* zTXt */
- };
+ /* These byte strings were copied from png.h. If a future version
+ * of readpng2.c recognizes more chunks, add them to this list.
+ */
+ static PNG_CONST png_byte chunks_to_process[] = {
+ 98, 75, 71, 68, '\0', /* bKGD */
+ 103, 65, 77, 65, '\0', /* gAMA */
+ 115, 82, 71, 66, '\0', /* sRGB */
+ };
- png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
- chunks_to_ignore, sizeof(chunks_to_ignore)/5);
+ /* Ignore all chunks except for IHDR, PLTE, tRNS, IDAT, and IEND */
+ png_set_keep_unknown_chunks(png_ptr, -1 /* PNG_HANDLE_CHUNK_NEVER */,
+ NULL, -1);
+
+ /* But do not ignore chunks in the "chunks_to_process" list */
+ png_set_keep_unknown_chunks(png_ptr,
+ 0 /* PNG_HANDLE_CHUNK_AS_DEFAULT */, chunks_to_process,
+ sizeof(chunks_to_process)/5);
}
#endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
diff --git a/libpng-manual.txt b/libpng-manual.txt
index 2f7bca3..dda62ad 100644
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@@ -1,6 +1,6 @@
libpng-manual.txt - A description on how to use and modify libpng
- libpng version 1.6.0beta25 - June 12, 2012
+ libpng version 1.6.0beta25 - June 16, 2012
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2011 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@
Based on:
- libpng versions 0.97, January 1998, through 1.6.0beta25 - June 12, 2012
+ libpng versions 0.97, January 1998, through 1.6.0beta25 - June 16, 2012
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2011 Glenn Randers-Pehrson
@@ -572,6 +572,7 @@
png_set_keep_unknown_chunks(png_ptr, keep,
chunk_list, num_chunks);
+
keep - 0: default unknown chunk handling
1: ignore; do not keep
2: keep only if safe-to-copy
@@ -585,11 +586,16 @@
chunk_list - list of chunks affected (a byte string,
five bytes per chunk, NULL or '\0' if
- num_chunks is 0)
+ num_chunks is positive; ignored if
+ numchunks <= 0).
num_chunks - number of chunks affected; if 0, all
- unknown chunks are affected. If nonzero,
- only the chunks in the list are affected
+ unknown chunks are affected. If positive,
+ only the chunks in the list are affected,
+ and if negative all unknown chunks and
+ all known chunks except for the IHDR,
+ PLTE, tRNS, IDAT, and IEND chunks are
+ affected.
Unknown chunks declared in this way will be saved as raw data onto a
list of png_unknown_chunk structures. If a chunk that is normally
@@ -5013,7 +5019,7 @@
XVI. 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.
@@ -5022,16 +5028,16 @@
upward through 1.6.0beta25 are Y2K compliant. It is my belief that earlier
versions were also Y2K compliant.
-Libpng only has three year fields. One is a 2-byte unsigned integer that
-will hold years up to 65535. The other two hold the date in text
-format, and will hold years up to 9999.
+Libpng only has two year fields. One is a 2-byte unsigned integer
+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 strings are
- "png_charp time_buffer" in png_struct and
- "near_time_buffer", which is a local character string in png.c.
+The string is
+ "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:
diff --git a/libpng.3 b/libpng.3
index 3218d30..2916889 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,4 +1,4 @@
-.TH LIBPNG 3 "June 12, 2012"
+.TH LIBPNG 3 "June 16, 2012"
.SH NAME
libpng \- Portable Network Graphics (PNG) Reference Library 1.6.0beta25
.SH SYNOPSIS
@@ -1007,7 +1007,7 @@
.SH LIBPNG.TXT
libpng-manual.txt - A description on how to use and modify libpng
- libpng version 1.6.0beta25 - June 12, 2012
+ libpng version 1.6.0beta25 - June 16, 2012
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2011 Glenn Randers-Pehrson
@@ -1018,7 +1018,7 @@
Based on:
- libpng versions 0.97, January 1998, through 1.6.0beta25 - June 12, 2012
+ libpng versions 0.97, January 1998, through 1.6.0beta25 - June 16, 2012
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2011 Glenn Randers-Pehrson
@@ -1579,6 +1579,7 @@
png_set_keep_unknown_chunks(png_ptr, keep,
chunk_list, num_chunks);
+
keep - 0: default unknown chunk handling
1: ignore; do not keep
2: keep only if safe-to-copy
@@ -1592,11 +1593,16 @@
chunk_list - list of chunks affected (a byte string,
five bytes per chunk, NULL or '\0' if
- num_chunks is 0)
+ num_chunks is positive; ignored if
+ numchunks <= 0).
num_chunks - number of chunks affected; if 0, all
- unknown chunks are affected. If nonzero,
- only the chunks in the list are affected
+ unknown chunks are affected. If positive,
+ only the chunks in the list are affected,
+ and if negative all unknown chunks and
+ all known chunks except for the IHDR,
+ PLTE, tRNS, IDAT, and IEND chunks are
+ affected.
Unknown chunks declared in this way will be saved as raw data onto a
list of png_unknown_chunk structures. If a chunk that is normally
@@ -6021,7 +6027,7 @@
.SH XVI. 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.
@@ -6030,16 +6036,16 @@
upward through 1.6.0beta25 are Y2K compliant. It is my belief that earlier
versions were also Y2K compliant.
-Libpng only has three year fields. One is a 2-byte unsigned integer that
-will hold years up to 65535. The other two hold the date in text
-format, and will hold years up to 9999.
+Libpng only has two year fields. One is a 2-byte unsigned integer
+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 strings are
- "png_charp time_buffer" in png_struct and
- "near_time_buffer", which is a local character string in png.c.
+The string is
+ "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:
@@ -6289,7 +6295,7 @@
Thanks to Frank J. T. Wojcik for helping with the documentation.
-Libpng version 1.6.0beta25 - June 12, 2012:
+Libpng version 1.6.0beta25 - June 16, 2012:
Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
@@ -6312,7 +6318,7 @@
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) 2004,2006-2007 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
@@ -6411,7 +6417,7 @@
Glenn Randers-Pehrson
glennrp at users.sourceforge.net
-June 12, 2012
+June 16, 2012
.\" end of man page
diff --git a/png.h b/png.h
index b177fd5..8151eab 100644
--- a/png.h
+++ b/png.h
@@ -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 @@
#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));
diff --git a/pngread.c b/pngread.c
index 32b01dd..928525f 100644
--- a/pngread.c
+++ b/pngread.c
@@ -1462,31 +1462,26 @@
*
* This provides a small performance improvement and eliminates any
* potential vulnerability to security problems in the unused chunks.
- *
- * TODO: make it so that this is an explicit list to process, not a list
- * to ignore?
*/
{
- static PNG_CONST png_byte chunks_to_ignore[] = {
- 104, 73, 83, 84, '\0', /* hIST */
- 105, 84, 88, 116, '\0', /* iTXt */
- 111, 70, 70, 115, '\0', /* oFFs */
- 112, 67, 65, 76, '\0', /* pCAL */
- 112, 72, 89, 115, '\0', /* pHYs */
- 115, 67, 65, 76, '\0', /* sCAL */
- 115, 80, 76, 84, '\0', /* sPLT */
- 116, 69, 88, 116, '\0', /* tEXt */
- 116, 73, 77, 69, '\0', /* tIME */
- 122, 84, 88, 116, '\0' /* zTXt */
- };
+ static PNG_CONST png_byte chunks_to_process[] = {
+ 98, 75, 71, 68, '\0', /* bKGD */
+ 99, 72, 82, 77, '\0', /* cHRM */
+ 103, 65, 77, 65, '\0', /* gAMA */
+ 105, 67, 67, 80, '\0', /* iCCP */
+ 115, 66, 73, 84, '\0', /* sBIT */
+ 115, 82, 71, 66, '\0', /* sRGB */
+ };
- /* Ignore unknown chunks */
+ /* Ignore unknown chunks and all other chunks except for the
+ * IHDR, PLTE, tRNS, IDAT, and IEND chunks.
+ */
png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
- NULL, 0);
+ NULL, -1);
- /* Ignore known but unused chunks */
- png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
- chunks_to_ignore, (sizeof chunks_to_ignore)/5);
+ /* But do not ignore image data handling chunks */
+ png_set_keep_unknown_chunks(png_ptr, 0 /* PNG_HANDLE_CHUNK_AS_DEFAULT */,
+ chunks_to_process, (sizeof chunks_to_process)/5);
}
}
diff --git a/pngset.c b/pngset.c
index f197c84..65cb695 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1183,14 +1183,44 @@
else
png_ptr->flags &= ~PNG_FLAG_KEEP_UNSAFE_CHUNKS;
- return;
+ if (num_chunksIn == 0)
+ return;
}
+ if (num_chunksIn < 0)
+ {
+ /* Ignore all unknown chunks and all chunks recognized by
+ * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
+ */
+ static PNG_CONST png_byte chunks_to_ignore[] = {
+ 98, 75, 71, 68, '\0', /* bKGD */
+ 99, 72, 82, 77, '\0', /* cHRM */
+ 103, 65, 77, 65, '\0', /* gAMA */
+ 104, 73, 83, 84, '\0', /* hIST */
+ 105, 67, 67, 80, '\0', /* iCCP */
+ 105, 84, 88, 116, '\0', /* iTXt */
+ 111, 70, 70, 115, '\0', /* oFFs */
+ 112, 67, 65, 76, '\0', /* pCAL */
+ 112, 72, 89, 115, '\0', /* pHYs */
+ 115, 66, 73, 84, '\0', /* sBIT */
+ 115, 67, 65, 76, '\0', /* sCAL */
+ 115, 80, 76, 84, '\0', /* sPLT */
+ 115, 84, 69, 82, '\0', /* sTER */
+ 115, 82, 71, 66, '\0', /* sRGB */
+ 116, 69, 88, 116, '\0', /* tEXt */
+ 116, 73, 77, 69, '\0', /* tIME */
+ 122, 84, 88, 116, '\0' /* zTXt */
+ };
+
+ chunk_list = chunks_to_ignore;
+ num_chunks = (unsigned int) sizeof(chunks_to_ignore)/5;
+ }
+
if (chunk_list == NULL)
return;
- /* The argument is >0 */
- num_chunks = (unsigned int)num_chunksIn;
+ if (num_chunksIn > 0)
+ num_chunks = (unsigned int)num_chunksIn;
old_num_chunks = png_ptr->num_chunk_list;
new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
