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[master] Trivial revision of documentation.
This commit is contained in:
Glenn Randers-Pehrson
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@ -1,6 +1,6 @@
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libpng.txt - A description on how to use and modify libpng
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libpng version 1.4.2rc02 - April 16, 2010
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libpng version 1.4.2rc03 - April 16, 2010
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Updated and distributed by Glenn Randers-Pehrson
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<glennrp at users.sourceforge.net>
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Copyright (c) 1998-2009 Glenn Randers-Pehrson
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@ -11,7 +11,7 @@ libpng.txt - A description on how to use and modify libpng
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Based on:
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libpng versions 0.97, January 1998, through 1.4.2rc02 - April 16, 2010
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libpng versions 0.97, January 1998, through 1.4.2rc03 - April 16, 2010
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Updated and distributed by Glenn Randers-Pehrson
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Copyright (c) 1998-2009 Glenn Randers-Pehrson
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@ -241,9 +241,13 @@ free any memory.
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}
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If you would rather avoid the complexity of setjmp/longjmp issues,
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you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
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you can compile libpng with PNG_NO_SETJMP, in which case
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errors will result in a call to PNG_ABORT() which defaults to abort().
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You can #define PNG_ABORT() to a function that does something
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more useful than abort(), as long as your function does not
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return.
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Now you need to set up the input code. The default for libpng is to
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use the C function fread(). If you use this, you will need to pass a
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valid FILE * in the function png_init_io(). Be sure that the file is
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@ -899,7 +903,7 @@ things.
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As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
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added. It expands the sample depth without changing tRNS to alpha.
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As of libpng version 1.4.2rc02, not all possible expansions are supported.
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As of libpng version 1.4.2rc03, not all possible expansions are supported.
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In the following table, the 01 means grayscale with depth<8, 31 means
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indexed with depth<8, other numerals represent the color type, "T" means
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@ -1722,9 +1726,13 @@ section below for more information on the libpng error handling.
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return;
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If you would rather avoid the complexity of setjmp/longjmp issues,
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you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
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you can compile libpng with PNG_NO_SETJMP, in which case
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errors will result in a call to PNG_ABORT() which defaults to abort().
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You can #define PNG_ABORT() to a function that does something
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more useful than abort(), as long as your function does not
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return.
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Now you need to set up the output code. The default for libpng is to
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use the C function fwrite(). If you use this, you will need to pass a
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valid FILE * in the function png_init_io(). Be sure that the file is
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@ -2585,8 +2593,9 @@ Error handling in libpng is done through png_error() and png_warning().
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Errors handled through png_error() are fatal, meaning that png_error()
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should never return to its caller. Currently, this is handled via
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setjmp() and longjmp() (unless you have compiled libpng with
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PNG_SETJMP_NOT_SUPPORTED, in which case it is handled via PNG_ABORT()),
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but you could change this to do things like exit() if you should wish.
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PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
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but you could change this to do things like exit() if you should wish,
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as long as your function does not return.
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On non-fatal errors, png_warning() is called
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to print a warning message, and then control returns to the calling code.
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@ -3217,12 +3226,12 @@ the statement that follows the comment:
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/* Single-line comment */
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statement;
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/* Multiple-line
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* comment
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/* This is a multiple-line
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* comment.
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*/
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statement;
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Very short comments can be placed at the end of the statement
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Very short comments can be placed after the end of the statement
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to which they pertain:
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statement; /* comment */
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@ -3269,9 +3278,9 @@ macros begin with "PNG_".
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We put a space after each comma and after each semicolon
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in "for" statments, and we put spaces before and after each
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C binary operator and after "for" or "while". We don't
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put a space between a typecast and the expression being
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cast, nor do we put one between a function name and the
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C binary operator and after "for" or "while", and before
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"?". We don't put a space between a typecast and the expression
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being cast, nor do we put one between a function name and the
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left parenthesis that follows it:
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for (i = 2; i > 0; --i)
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@ -3294,7 +3303,7 @@ Since the PNG Development group is an ad-hoc body, we can't make
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an official declaration.
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This is your unofficial assurance that libpng from version 0.71 and
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upward through 1.4.2rc02 are Y2K compliant. It is my belief that earlier
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upward through 1.4.2rc03 are Y2K compliant. It is my belief that earlier
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versions were also Y2K compliant.
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Libpng only has three year fields. One is a 2-byte unsigned integer that
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43
libpng.3
43
libpng.3
@ -1,6 +1,6 @@
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.TH LIBPNG 3 "April 16, 2010"
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.SH NAME
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libpng \- Portable Network Graphics (PNG) Reference Library 1.4.2rc02
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libpng \- Portable Network Graphics (PNG) Reference Library 1.4.2rc03
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.SH SYNOPSIS
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\fI\fB
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@ -785,7 +785,7 @@ Following is a copy of the libpng.txt file that accompanies libpng.
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.SH LIBPNG.TXT
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libpng.txt - A description on how to use and modify libpng
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libpng version 1.4.2rc02 - April 16, 2010
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libpng version 1.4.2rc03 - April 16, 2010
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Updated and distributed by Glenn Randers-Pehrson
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<glennrp at users.sourceforge.net>
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Copyright (c) 1998-2009 Glenn Randers-Pehrson
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@ -796,7 +796,7 @@ libpng.txt - A description on how to use and modify libpng
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Based on:
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libpng versions 0.97, January 1998, through 1.4.2rc02 - April 16, 2010
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libpng versions 0.97, January 1998, through 1.4.2rc03 - April 16, 2010
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Updated and distributed by Glenn Randers-Pehrson
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Copyright (c) 1998-2009 Glenn Randers-Pehrson
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@ -1026,9 +1026,13 @@ free any memory.
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}
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If you would rather avoid the complexity of setjmp/longjmp issues,
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you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
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you can compile libpng with PNG_NO_SETJMP, in which case
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errors will result in a call to PNG_ABORT() which defaults to abort().
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You can #define PNG_ABORT() to a function that does something
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more useful than abort(), as long as your function does not
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return.
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Now you need to set up the input code. The default for libpng is to
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use the C function fread(). If you use this, you will need to pass a
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valid FILE * in the function png_init_io(). Be sure that the file is
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@ -1684,7 +1688,7 @@ things.
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As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
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added. It expands the sample depth without changing tRNS to alpha.
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As of libpng version 1.4.2rc02, not all possible expansions are supported.
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As of libpng version 1.4.2rc03, not all possible expansions are supported.
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In the following table, the 01 means grayscale with depth<8, 31 means
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indexed with depth<8, other numerals represent the color type, "T" means
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@ -2507,9 +2511,13 @@ section below for more information on the libpng error handling.
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return;
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If you would rather avoid the complexity of setjmp/longjmp issues,
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you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
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you can compile libpng with PNG_NO_SETJMP, in which case
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errors will result in a call to PNG_ABORT() which defaults to abort().
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You can #define PNG_ABORT() to a function that does something
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more useful than abort(), as long as your function does not
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return.
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Now you need to set up the output code. The default for libpng is to
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use the C function fwrite(). If you use this, you will need to pass a
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valid FILE * in the function png_init_io(). Be sure that the file is
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@ -3370,8 +3378,9 @@ Error handling in libpng is done through png_error() and png_warning().
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Errors handled through png_error() are fatal, meaning that png_error()
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should never return to its caller. Currently, this is handled via
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setjmp() and longjmp() (unless you have compiled libpng with
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PNG_SETJMP_NOT_SUPPORTED, in which case it is handled via PNG_ABORT()),
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but you could change this to do things like exit() if you should wish.
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PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
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but you could change this to do things like exit() if you should wish,
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as long as your function does not return.
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On non-fatal errors, png_warning() is called
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to print a warning message, and then control returns to the calling code.
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@ -4002,12 +4011,12 @@ the statement that follows the comment:
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/* Single-line comment */
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statement;
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/* Multiple-line
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* comment
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/* This is a multiple-line
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* comment.
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*/
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statement;
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Very short comments can be placed at the end of the statement
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Very short comments can be placed after the end of the statement
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to which they pertain:
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statement; /* comment */
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@ -4054,9 +4063,9 @@ macros begin with "PNG_".
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We put a space after each comma and after each semicolon
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in "for" statments, and we put spaces before and after each
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C binary operator and after "for" or "while". We don't
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put a space between a typecast and the expression being
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cast, nor do we put one between a function name and the
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C binary operator and after "for" or "while", and before
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"?". We don't put a space between a typecast and the expression
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being cast, nor do we put one between a function name and the
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left parenthesis that follows it:
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for (i = 2; i > 0; --i)
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@ -4079,7 +4088,7 @@ Since the PNG Development group is an ad-hoc body, we can't make
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an official declaration.
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This is your unofficial assurance that libpng from version 0.71 and
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upward through 1.4.2rc02 are Y2K compliant. It is my belief that earlier
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upward through 1.4.2rc03 are Y2K compliant. It is my belief that earlier
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versions were also Y2K compliant.
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Libpng only has three year fields. One is a 2-byte unsigned integer that
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@ -4313,7 +4322,7 @@ possible without all of you.
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Thanks to Frank J. T. Wojcik for helping with the documentation.
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Libpng version 1.4.2rc02 - April 16, 2010:
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Libpng version 1.4.2rc03 - April 16, 2010:
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Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
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Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
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@ -4336,7 +4345,7 @@ this sentence.
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This code is released under the libpng license.
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libpng versions 1.2.6, August 15, 2004, through 1.4.2rc02, April 16, 2010, are
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libpng versions 1.2.6, August 15, 2004, through 1.4.2rc03, April 16, 2010, are
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Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are
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distributed according to the same disclaimer and license as libpng-1.2.5
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with the following individual added to the list of Contributing Authors
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