[devel] Revised png_check_IHDR() again
to check info_ptr members instead of the contents of the returned parameters.
diff --git a/ANNOUNCE b/ANNOUNCE
index f83ee0e..6429ae0 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
-Libpng 1.4.0beta85 - September 30, 2009
+Libpng 1.4.0beta85 - October 1, 2009
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.
@@ -570,7 +570,9 @@
Fixed some inconsistent indentation in pngconf.h
Revised png_check_IHDR() to add a test for width variable less than 32-bit.
-version 1.4.0beta85 [September 30, 2009]
+version 1.4.0beta85 [October 1, 2009]
+ Revised png_check_IHDR() again, to check info_ptr members instead of
+ the contents of the returned parameters.
version 1.4.0betaN [future]
Build shared libraries with -lz and sometimes -lm.
diff --git a/CHANGES b/CHANGES
index 9cfea81..0e89025 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2256,7 +2256,9 @@
Fixed some inconsistent indentation in pngconf.h
Revised png_check_IHDR() to add a test for width variable less than 32-bit.
-version 1.4.0beta85 [September 30, 2009]
+version 1.4.0beta85 [October 1, 2009]
+ Revised png_check_IHDR() again, to check info_ptr members instead of
+ the contents of the returned parameters.
version 1.4.0betaN [future]
Build shared libraries with -lz and sometimes -lm.
diff --git a/libpng-1.4.0beta85.txt b/libpng-1.4.0beta85.txt
index 33d18f9..1e29fd9 100644
--- a/libpng-1.4.0beta85.txt
+++ b/libpng-1.4.0beta85.txt
@@ -1,6 +1,6 @@
libpng.txt - A description on how to use and modify libpng
- libpng version 1.4.0beta85 - September 30, 2009
+ libpng version 1.4.0beta85 - October 1, 2009
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2009 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@
Based on:
- libpng versions 0.97, January 1998, through 1.4.0beta85 - September 30, 2009
+ libpng versions 0.97, January 1998, through 1.4.0beta85 - October 1, 2009
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2009 Glenn Randers-Pehrson
@@ -557,10 +557,33 @@
for PNG 1.0)
interlace_type - (PNG_INTERLACE_NONE or
PNG_INTERLACE_ADAM7)
- Any or all of interlace_type, compression_type, of
+
+ Any or all of interlace_type, compression_type, or
filter_method can be NULL if you are
not interested in their values.
+ Note that png_get_IHDR() returns 32-bit data into
+ the application's width and height variables.
+ This is an unsafe situation if these are 16-bit
+ variables. In such situations, the
+ png_get_image_width() and png_get_image_height()
+ functions described below are safer.
+
+ width = png_get_image_width(png_ptr,
+ info_ptr);
+ height = png_get_image_height(png_ptr,
+ info_ptr);
+ bit_depth = png_get_bit_depth(png_ptr,
+ info_ptr);
+ color_type = png_get_color_type(png_ptr,
+ info_ptr);
+ filter_method = png_get_filter_type(png_ptr,
+ info_ptr);
+ compression_type = png_get_compression_type(png_ptr,
+ info_ptr);
+ interlace_type = png_get_interlace_type(png_ptr,
+ info_ptr);
+
channels = png_get_channels(png_ptr, info_ptr);
channels - number of channels of info for the
color type (valid values are 1 (GRAY,
@@ -580,23 +603,6 @@
be in signature[4] through signature[7]
(see png_set_sig_bytes())).
-
- width = png_get_image_width(png_ptr,
- info_ptr);
- height = png_get_image_height(png_ptr,
- info_ptr);
- bit_depth = png_get_bit_depth(png_ptr,
- info_ptr);
- color_type = png_get_color_type(png_ptr,
- info_ptr);
- filter_method = png_get_filter_type(png_ptr,
- info_ptr);
- compression_type = png_get_compression_type(png_ptr,
- info_ptr);
- interlace_type = png_get_interlace_type(png_ptr,
- info_ptr);
-
-
These are also important, but their validity depends on whether the chunk
has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and
png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the
@@ -3205,7 +3211,7 @@
XIII. Y2K Compliance in libpng
-September 30, 2009
+October 1, 2009
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
diff --git a/png.c b/png.c
index 37802fe..a24f598 100644
--- a/png.c
+++ b/png.c
@@ -1,7 +1,7 @@
/* png.c - location for general purpose libpng functions
*
- * Last changed in libpng 1.4.0 [September 30, 2009]
+ * Last changed in libpng 1.4.0 [October 1, 2009]
* Copyright (c) 1998-2009 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.)
@@ -547,13 +547,13 @@
#else
#ifdef __STDC__
return ((png_charp) PNG_STRING_NEWLINE \
- "libpng version x 1.4.0beta85 - September 30, 2009" PNG_STRING_NEWLINE \
+ "libpng version x 1.4.0beta85 - October 1, 2009" PNG_STRING_NEWLINE \
"Copyright (c) 1998-2009 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
"Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
"Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
PNG_STRING_NEWLINE);
#else
- return ((png_charp) "libpng version 1.4.0beta85 - September 30, 2009\
+ return ((png_charp) "libpng version 1.4.0beta85 - October 1, 2009\
Copyright (c) 1998-2009 Glenn Randers-Pehrson\
Copyright (c) 1996-1997 Andreas Dilger\
Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.");
@@ -796,14 +796,6 @@
#endif
{
png_warning(png_ptr, "Image width exceeds user limit in IHDR");
- if ((width >> 16) == height)
- {
- /* This is likely to be caused by passing consecutive addresses
- * of 16-bit width and height variables to png_get_IHDR(), which
- * overflowed when we tried to fill them with 31-bit data.
- */
- png_warning(png_ptr, "High bytes of width == low bytes of height");
- }
error = 1;
}
diff --git a/pngget.c b/pngget.c
index cd9d62e..556b43d 100644
--- a/pngget.c
+++ b/pngget.c
@@ -1,7 +1,7 @@
/* pngget.c - retrieval of values from info struct
*
- * Last changed in libpng 1.4.0 [September 30, 2009]
+ * Last changed in libpng 1.4.0 [October 1, 2009]
* Copyright (c) 1998-2009 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.)
@@ -579,10 +579,6 @@
int *filter_type)
{
- int test_interlace_type = 0;
- int test_compression_type = 0;
- int test_filter_type = 0;
-
png_debug1(1, "in %s retrieval function", "IHDR");
if (png_ptr == NULL || info_ptr == NULL || width == NULL ||
@@ -595,26 +591,22 @@
*color_type = info_ptr->color_type;
if (compression_type != NULL)
- {
*compression_type = info_ptr->compression_type;
- test_compression_type=*compression_type;
- }
if (filter_type != NULL)
- {
*filter_type = info_ptr->filter_type;
- test_filter_type=*filter_type;
- }
if (interlace_type != NULL)
- {
*interlace_type = info_ptr->interlace_type;
- test_interlace_type=*interlace_type;
- }
- png_check_IHDR (png_ptr, *width, *height, *bit_depth, *color_type,
- info_ptr->interlace_type, info_ptr->compression_type,
- info_ptr->filter_type);
+ /* This is redundant if we can be sure that the info_ptr values were all
+ * assigned in png_set_IHDR(). We do the check anyhow in case an
+ * application has ignored our advice not to mess with the members
+ * of info_ptr directly.
+ */
+ png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+ info_ptr->compression_type, info_ptr->filter_type);
return (1);
}
diff --git a/pngset.c b/pngset.c
index bd1f496..b494cd5 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1,7 +1,7 @@
/* pngset.c - storage of image information into info struct
*
- * Last changed in libpng 1.4.0 [September 30, 2009]
+ * Last changed in libpng 1.4.0 [October 1, 2009]
* Copyright (c) 1998-2009 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.)
@@ -227,16 +227,18 @@
if (png_ptr == NULL || info_ptr == NULL)
return;
- png_check_IHDR (png_ptr, width, height, bit_depth, color_type,
- interlace_type, compression_type, filter_type);
-
info_ptr->width = width;
info_ptr->height = height;
info_ptr->bit_depth = (png_byte)bit_depth;
- info_ptr->color_type =(png_byte) color_type;
+ info_ptr->color_type = (png_byte)color_type;
info_ptr->compression_type = (png_byte)compression_type;
info_ptr->filter_type = (png_byte)filter_type;
info_ptr->interlace_type = (png_byte)interlace_type;
+
+ png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+ info_ptr->compression_type, info_ptr->filter_type);
+
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
info_ptr->channels = 1;
else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
