[libpng16] Revise man page to demonstrate dealing with unknown chunk
handling in libpng.1.5.x and with bugs in libpng-1.4.x and earlier.
diff --git a/libpng-manual.txt b/libpng-manual.txt
index 3adfb26..09f111d 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 1.6.3beta03 - April 27, 2013
+ libpng version 1.6.3beta03 - April 29, 2013
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2013 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@
Based on:
- libpng versions 0.97, January 1998, through 1.6.3beta03 - April 27, 2013
+ libpng versions 0.97, January 1998, through 1.6.3beta03 - April 29, 2013
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2013 Glenn Randers-Pehrson
@@ -3104,17 +3104,33 @@
#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
/* Set unknown chunk data */
- png_unknown_chunk unkc[2];
- png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS, NULL, 0);
- strcpy((char *) unkc[0].name, "prVt";
- unkc[0].data = (unsigned char *) "PRIVATE CHUNK DATA";
- unkc[0].size = strlen(unkc[0].data)+1;
- unkc[0].location = PNG_HAVE_IHDR;
- strcpy((char *) unkc[1].name, "miNE";
- unkc[1].data = (unsigned char *) "MY CHUNK DATA";
- unkc[1].size = strlen(unkc[0].data)+1;
- unkc[1].location = PNG_AFTER_IDAT;
- png_set_unknown_chunks(png, info, unkc, 2);
+ png_unknown_chunk unk_chunk[2];
+ strcpy((char *) unk_chunk[0].name, "prVt";
+ unk_chunk[0].data = (unsigned char *) "PRIVATE DATA";
+ unk_chunk[0].size = strlen(unk_chunk[0].data)+1;
+ unk_chunk[0].location = PNG_HAVE_IHDR;
+ strcpy((char *) unk_chunk[1].name, "miNE";
+ unk_chunk[1].data = (unsigned char *) "MY CHUNK DATA";
+ unk_chunk[1].size = strlen(unk_chunk[0].data)+1;
+ unk_chunk[1].location = PNG_AFTER_IDAT;
+ png_set_unknown_chunks(write_ptr, write_info_ptr,
+ unk_chunk, 2);
+ /* Needed because miNE is not safe-to-copy */
+ png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS,
+ (png_bytep) "miNE", 1);
+ # if PNG_LIBPNG_VER < 10600
+ /* Deal with unknown chunk location bug in 1.5.x and earlier */
+ png_set_unknown_chunk_location(png, info, 0, PNG_HAVE_IHDR);
+ png_set_unknown_chunk_location(png, info, 1, PNG_AFTER_IDAT);
+ # endif
+ # if PNG_LIBPNG_VER < 10500
+ /* PNG_AFTER_IDAT writes two copies of the chunk prior to libpng-1.5.0,
+ * one before IDAT and another after IDAT, so don't use it; only use
+ * PNG_HAVE_IHDR location. This call resets the location previously
+ * set by assignment and png_set_unknown_chunk_location() for chunk 1.
+ */
+ png_set_unknown_chunk_location(png, info, 1, PNG_HAVE_IHDR);
+ # endif
#endif
The high-level write interface
@@ -4965,7 +4981,7 @@
to pngpriv.h, where it is not accessible by applications. Applications that
need access to information in string.h must add an '#include <string.h>'
directive. It does not matter whether this is placed prior to or after
-the '"#include png.h"' directive.
+the '#include "png.h"' directive.
The following API are now DEPRECATED:
png_info_init_3()
@@ -5181,7 +5197,7 @@
XVI. Y2K Compliance in libpng
-April 27, 2013
+April 29, 2013
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
diff --git a/libpng.3 b/libpng.3
index 597f9d0..d56b0b8 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,4 +1,4 @@
-.TH LIBPNG 3 "April 27, 2013"
+.TH LIBPNG 3 "April 29, 2013"
.SH NAME
libpng \- Portable Network Graphics (PNG) Reference Library 1.6.3beta03
.SH SYNOPSIS
@@ -504,7 +504,7 @@
.SH LIBPNG.TXT
libpng-manual.txt - A description on how to use and modify libpng
- libpng version 1.6.3beta03 - April 27, 2013
+ libpng version 1.6.3beta03 - April 29, 2013
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2013 Glenn Randers-Pehrson
@@ -515,7 +515,7 @@
Based on:
- libpng versions 0.97, January 1998, through 1.6.3beta03 - April 27, 2013
+ libpng versions 0.97, January 1998, through 1.6.3beta03 - April 29, 2013
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2013 Glenn Randers-Pehrson
@@ -3608,17 +3608,33 @@
#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
/* Set unknown chunk data */
- png_unknown_chunk unkc[2];
- png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS, NULL, 0);
- strcpy((char *) unkc[0].name, "prVt";
- unkc[0].data = (unsigned char *) "PRIVATE CHUNK DATA";
- unkc[0].size = strlen(unkc[0].data)+1;
- unkc[0].location = PNG_HAVE_IHDR;
- strcpy((char *) unkc[1].name, "miNE";
- unkc[1].data = (unsigned char *) "MY CHUNK DATA";
- unkc[1].size = strlen(unkc[0].data)+1;
- unkc[1].location = PNG_AFTER_IDAT;
- png_set_unknown_chunks(png, info, unkc, 2);
+ png_unknown_chunk unk_chunk[2];
+ strcpy((char *) unk_chunk[0].name, "prVt";
+ unk_chunk[0].data = (unsigned char *) "PRIVATE DATA";
+ unk_chunk[0].size = strlen(unk_chunk[0].data)+1;
+ unk_chunk[0].location = PNG_HAVE_IHDR;
+ strcpy((char *) unk_chunk[1].name, "miNE";
+ unk_chunk[1].data = (unsigned char *) "MY CHUNK DATA";
+ unk_chunk[1].size = strlen(unk_chunk[0].data)+1;
+ unk_chunk[1].location = PNG_AFTER_IDAT;
+ png_set_unknown_chunks(write_ptr, write_info_ptr,
+ unk_chunk, 2);
+ /* Needed because miNE is not safe-to-copy */
+ png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS,
+ (png_bytep) "miNE", 1);
+ # if PNG_LIBPNG_VER < 10600
+ /* Deal with unknown chunk location bug in 1.5.x and earlier */
+ png_set_unknown_chunk_location(png, info, 0, PNG_HAVE_IHDR);
+ png_set_unknown_chunk_location(png, info, 1, PNG_AFTER_IDAT);
+ # endif
+ # if PNG_LIBPNG_VER < 10500
+ /* PNG_AFTER_IDAT writes two copies of the chunk prior to libpng-1.5.0,
+ * one before IDAT and another after IDAT, so don't use it; only use
+ * PNG_HAVE_IHDR location. This call resets the location previously
+ * set by assignment and png_set_unknown_chunk_location() for chunk 1.
+ */
+ png_set_unknown_chunk_location(png, info, 1, PNG_HAVE_IHDR);
+ # endif
#endif
.SS The high-level write interface
@@ -5470,7 +5486,7 @@
to pngpriv.h, where it is not accessible by applications. Applications that
need access to information in string.h must add an '#include <string.h>'
directive. It does not matter whether this is placed prior to or after
-the '"#include png.h"' directive.
+the '#include "png.h"' directive.
The following API are now DEPRECATED:
png_info_init_3()
@@ -5686,7 +5702,7 @@
.SH XVI. Y2K Compliance in libpng
-April 27, 2013
+April 29, 2013
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
@@ -5963,7 +5979,7 @@
Thanks to Frank J. T. Wojcik for helping with the documentation.
-Libpng version 1.6.3beta03 - April 27, 2013:
+Libpng version 1.6.3beta03 - April 29, 2013:
Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
@@ -5986,7 +6002,7 @@
This code is released under the libpng license.
-libpng versions 1.2.6, August 15, 2004, through 1.6.3beta03, April 27, 2013, are
+libpng versions 1.2.6, August 15, 2004, through 1.6.3beta03, April 29, 2013, 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
@@ -6085,7 +6101,7 @@
Glenn Randers-Pehrson
glennrp at users.sourceforge.net
-April 27, 2013
+April 29, 2013
.\" end of man page
