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[libpng17] Merge recent changes to the manual and pngrutil.c from libpng-1.6.14beta04.

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Glenn Randers-Pehrson 2014-09-27 18:49:42 -05:00
parent 34e49ae1bc
commit 2799bf9a4f
4 changed files with 106 additions and 58 deletions
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34
INSTALL
View File

@ -28,7 +28,9 @@ On Unix/Linux and similar systems, you can simply type
make check
make install
and ignore the rest of this document.
and ignore the rest of this document. "/path" is the path to the directory
where you want to install the libpng "lib", "include", and "bin"
subdirectories.
II. Rebuilding the configure scripts
@ -64,8 +66,8 @@ Or you can use one of the "projects" in the "projects" directory.
Before installing libpng, you must first install zlib, if it
is not already on your system. zlib can usually be found
wherever you got libpng. zlib can be placed in another directory,
at the same level as libpng.
wherever you got libpng; otherwise go to http://zlib.net. You can place
zlib in in the same directory as libpng or in another directory.
If your system already has a preinstalled zlib you will still need
to have access to the zlib.h and zconf.h include files that
@ -93,6 +95,10 @@ If you want to use "cmake" (see www.cmake.org), type
make
make install
As when using the simple configure method described above, "/path" points to
the installation directory where you want to put the libpng "lib", "include",
and "bin" subdirectories.
V. Directory structure
You can rename the directories that you downloaded (they
@ -322,11 +328,12 @@ unmodified, default, libpng API and thus would probably fail to link.
These mechanisms still work in the configure build and in any makefile
build that builds pnglibconf.h, although the feature selection macros
have changed somewhat as described above. In 1.5.0, however, pngusr.h is
processed only once, when the exported header file pnglibconf.h is built.
pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the
build of pnglibconf.h and it is never included in an application build.
processed only once, at the time the exported header file pnglibconf.h is
built. pngconf.h no longer includes pngusr.h; therefore, pngusr.h is ignored
after the build of pnglibconf.h and it is never included in an application
build.
The rarely used alternative of adding a list of feature macros to the
The formerly used alternative of adding a list of feature macros to the
CPPFLAGS setting in the build also still works; however, the macros will be
copied to pnglibconf.h and this may produce macro redefinition warnings
when the individual C files are compiled.
@ -342,12 +349,19 @@ functioning awk called 'nawk'.
Configuration options are now documented in scripts/pnglibconf.dfa. This
file also includes dependency information that ensures a configuration is
consistent; that is, if a feature is switched off dependent features are
also removed. As a recommended alternative to using feature macros in
consistent; that is, if a feature is switched off, dependent features are
also switched off. As a recommended alternative to using feature macros in
pngusr.h a system builder may also define equivalent options in pngusr.dfa
(or, indeed, any file) and add that to the configuration by setting
DFA_XTRA to the file name. The makefiles in contrib/pngminim illustrate
how to do this, and a case where pngusr.h is still required.
how to do this, and also illustrate a case where pngusr.h is still required.
After you have built libpng, the definitions that were recorded in
pnglibconf.h are available to your application (pnglibconf.h is included
in png.h and gets installed alongside png.h and pngconf.h in your
$PREFIX/include directory). Do not edit pnglibconf.h after you have built
libpng, because than the settings would not accurately reflect the settings
that were used to build libpng.
XV. Configuring libpng for multiprocessing

47
libpng-manual.txt
View File

@ -1,6 +1,6 @@
libpng-manual.txt - A description on how to use and modify libpng
libpng version 1.7.0beta36 - August 6, 2014
libpng version 1.7.0beta36 - September 27, 2014
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2014 Glenn Randers-Pehrson
@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
Based on:
libpng versions 0.97, January 1998, through 1.7.0beta36 - August 6, 2014
libpng versions 0.97, January 1998, through 1.7.0beta36 - September 27, 2014
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2014 Glenn Randers-Pehrson
@ -5036,11 +5036,27 @@ Error detection in some chunks has improved; in particular the iCCP chunk
reader now does pretty complete validation of the basic format. Some bad
profiles that were previously accepted are now accepted with a warning or
rejected, depending upon the png_set_benign_errors() setting, in particular the
very old broken Microsoft/HP 3144-byte sRGB profile. The PNG spec requirement
that only grayscale profiles may appear in images with color type 0 or 4 and
that even if the image only contains gray pixels, only RGB profiles may appear
in images with color type 2, 3, or 6, is now enforced. The sRGB chunk
is allowed to appear in images with any color type.
very old broken Microsoft/HP 3144-byte sRGB profile. Starting with
libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by
means of
#if defined(PNG_SKIP_sRGB_CHECK_PROFILE) && \
defined(PNG_SET_OPTION_SUPPORTED)
png_set_option(png_ptr, PNG_SKIP_sRGB_CHECK_PROFILE,
PNG_OPTION_ON);
#endif
It's not a good idea to do this if you are using the "simplified API",
which needs to be able to recognize an sRGB profile conveyed via the iCCP
chunk.
The PNG spec requirement that only grayscale profiles may appear in images
with color type 0 or 4 and that even if the image only contains gray pixels,
only RGB profiles may appear in images with color type 2, 3, or 6, is now
enforced. The sRGB chunk is allowed to appear in images with any color type
and is interpreted by libpng to convey a one-tracer-curve gray profile or a
three-tracer-curve RGB profile as appropriate.
Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
an empty language field or an empty translated keyword. Both of these
@ -5239,12 +5255,15 @@ We mark all non-exported functions with "/* PRIVATE */"":
}
The prototypes for non-exported functions (except for those in
pngtest) appear in
pngpriv.h
above the comment that says
pngtest) appear in pngpriv.h above the comment that says
/* Maintainer: Put new private prototypes here ^ */
To avoid polluting the global namespace, the names of all exported
functions and variables begin with "png_", and all publicly visible C
preprocessor macros begin with "PNG". We request that applications that
use libpng *not* begin any of their own symbols with either of these strings.
We put a space after the "sizeof" operator and we omit the
optional parentheses around its argument when the argument
is an expression, not a type name, and we always enclose the
@ -5256,10 +5275,8 @@ sizeof operator, with its argument, in parentheses:
Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as
though it were a function.
To avoid polluting the global namespace, the names of all exported
functions and variables begin with "png_", and all publicly visible C
preprocessor macros begin with "PNG". We request that applications that
use libpng *not* begin any of their own symbols with either of these strings.
Control keywords if, for, while, and switch are always followed by a space
to distinguish them from function calls, which have no trailing space.
We put a space after each comma and after each semicolon
in "for" statements, and we put spaces before and after each
@ -5292,7 +5309,7 @@ Other rules can be inferred by inspecting the libpng source.
XVII. Y2K Compliance in libpng
August 6, 2014
September 27, 2014
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.

55
libpng.3
View File

@ -1,4 +1,4 @@
.TH LIBPNG 3 "August 6, 2014"
.TH LIBPNG 3 "September 27, 2014"
.SH NAME
libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta36
.SH SYNOPSIS
@ -494,7 +494,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
.SH LIBPNG.TXT
libpng-manual.txt - A description on how to use and modify libpng
libpng version 1.7.0beta36 - August 6, 2014
libpng version 1.7.0beta36 - September 27, 2014
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2014 Glenn Randers-Pehrson
@ -505,7 +505,7 @@ libpng-manual.txt - A description on how to use and modify libpng
Based on:
libpng versions 0.97, January 1998, through 1.7.0beta36 - August 6, 2014
libpng versions 0.97, January 1998, through 1.7.0beta36 - September 27, 2014
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2014 Glenn Randers-Pehrson
@ -5530,11 +5530,27 @@ Error detection in some chunks has improved; in particular the iCCP chunk
reader now does pretty complete validation of the basic format. Some bad
profiles that were previously accepted are now accepted with a warning or
rejected, depending upon the png_set_benign_errors() setting, in particular the
very old broken Microsoft/HP 3144-byte sRGB profile. The PNG spec requirement
that only grayscale profiles may appear in images with color type 0 or 4 and
that even if the image only contains gray pixels, only RGB profiles may appear
in images with color type 2, 3, or 6, is now enforced. The sRGB chunk
is allowed to appear in images with any color type.
very old broken Microsoft/HP 3144-byte sRGB profile. Starting with
libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by
means of
#if defined(PNG_SKIP_sRGB_CHECK_PROFILE) && \
defined(PNG_SET_OPTION_SUPPORTED)
png_set_option(png_ptr, PNG_SKIP_sRGB_CHECK_PROFILE,
PNG_OPTION_ON);
#endif
It's not a good idea to do this if you are using the "simplified API",
which needs to be able to recognize an sRGB profile conveyed via the iCCP
chunk.
The PNG spec requirement that only grayscale profiles may appear in images
with color type 0 or 4 and that even if the image only contains gray pixels,
only RGB profiles may appear in images with color type 2, 3, or 6, is now
enforced. The sRGB chunk is allowed to appear in images with any color type
and is interpreted by libpng to convey a one-tracer-curve gray profile or a
three-tracer-curve RGB profile as appropriate.
Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
an empty language field or an empty translated keyword. Both of these
@ -5733,12 +5749,15 @@ We mark all non-exported functions with "/* PRIVATE */"":
}
The prototypes for non-exported functions (except for those in
pngtest) appear in
pngpriv.h
above the comment that says
pngtest) appear in pngpriv.h above the comment that says
/* Maintainer: Put new private prototypes here ^ */
To avoid polluting the global namespace, the names of all exported
functions and variables begin with "png_", and all publicly visible C
preprocessor macros begin with "PNG". We request that applications that
use libpng *not* begin any of their own symbols with either of these strings.
We put a space after the "sizeof" operator and we omit the
optional parentheses around its argument when the argument
is an expression, not a type name, and we always enclose the
@ -5750,10 +5769,8 @@ sizeof operator, with its argument, in parentheses:
Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as
though it were a function.
To avoid polluting the global namespace, the names of all exported
functions and variables begin with "png_", and all publicly visible C
preprocessor macros begin with "PNG". We request that applications that
use libpng *not* begin any of their own symbols with either of these strings.
Control keywords if, for, while, and switch are always followed by a space
to distinguish them from function calls, which have no trailing space.
We put a space after each comma and after each semicolon
in "for" statements, and we put spaces before and after each
@ -5786,7 +5803,7 @@ Other rules can be inferred by inspecting the libpng source.
.SH XVII. Y2K Compliance in libpng
August 6, 2014
September 27, 2014
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
@ -6056,7 +6073,7 @@ possible without all of you.
Thanks to Frank J. T. Wojcik for helping with the documentation.
Libpng version 1.7.0beta36 - August 6, 2014:
Libpng version 1.7.0beta36 - September 27, 2014:
Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
@ -6079,7 +6096,7 @@ this sentence.
This code is released under the libpng license.
libpng versions 1.2.6, August 15, 2004, through 1.7.0beta36, August 6, 2014, are
libpng versions 1.2.6, August 15, 2004, through 1.7.0beta36, September 27, 2014, 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
@ -6178,7 +6195,7 @@ certification mark of the Open Source Initiative.
Glenn Randers-Pehrson
glennrp at users.sourceforge.net
August 6, 2014
September 27, 2014
.\" end of man page

22
pngrutil.c
View File

@ -1304,9 +1304,9 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
* chunk is just ignored, so does not invalidate the color space. An
* alternative is to set the 'invalid' flags at the start of this routine
* and only clear them in they were not set before and all the tests pass.
* The minimum 'deflate' stream is assumed to be just the 2 byte header and 4
* byte checksum. The keyword must be one character and there is a
* terminator (0) byte and the compression method.
* The minimum 'deflate' stream is assumed to be just the 2 byte header and
* 4 byte checksum. The keyword must be at least one character and there is
* a terminator (0) byte and the compression method.
*/
if (length < 9)
{
@ -1581,7 +1581,7 @@ png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
if (--png_ptr->user_chunk_cache_max == 1)
{
/* Warn the first time */
png_chunk_benign_error(png_ptr, "chunk cache full");
png_chunk_benign_error(png_ptr, "no space in chunk cache");
png_crc_finish(png_ptr, length);
return;
}
@ -2371,7 +2371,7 @@ png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
if (--png_ptr->user_chunk_cache_max == 1)
{
png_crc_finish(png_ptr, length);
png_chunk_benign_error(png_ptr, "chunk cache full");
png_chunk_benign_error(png_ptr, "no space in chunk cache");
return;
}
}
@ -2450,7 +2450,7 @@ png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
if (--png_ptr->user_chunk_cache_max == 1)
{
png_crc_finish(png_ptr, length);
png_chunk_benign_error(png_ptr, "chunk cache full");
png_chunk_benign_error(png_ptr, "no space in chunk cache");
return;
}
}
@ -2559,7 +2559,7 @@ png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
if (--png_ptr->user_chunk_cache_max == 1)
{
png_crc_finish(png_ptr, length);
png_chunk_benign_error(png_ptr, "chunk cache full");
png_chunk_benign_error(png_ptr, "no space in chunk cache");
return;
}
}
@ -2628,7 +2628,7 @@ png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
/* prefix_length should now be at the trailing '\0' of the translated
* keyword, but it may already be over the end. None of this arithmetic
* can overflow because chunks are at most 2^31 bytes long, but on 16-bit
* systems the available allocaton may overflow.
* systems the available allocation may overflow.
*/
++prefix_length;
@ -2660,7 +2660,7 @@ png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
buffer[uncompressed_length+prefix_length] = 0;
if (compressed != 0)
if (compressed == 0)
text.compression = PNG_ITXT_COMPRESSION_NONE;
else
@ -2884,7 +2884,7 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
{
case 2:
png_ptr->user_chunk_cache_max = 1;
png_chunk_benign_error(png_ptr, "chunk cache full");
png_chunk_benign_error(png_ptr, "no space in chunk cache");
/* FALL THROUGH */
case 1:
/* NOTE: prior to 1.6.0 this case resulted in an unknown critical
@ -3165,7 +3165,7 @@ png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
#endif /* !PNG_USE_COMPILE_TIME_MASKS */
/* Use the appropriate mask to copy the required bits. In some cases
* the byte mask will be 0 or 0xff, optimize these cases. row_width is
* the byte mask will be 0 or 0xff; optimize these cases. row_width is
* the number of pixels, but the code copies bytes, so it is necessary
* to special case the end.
*/