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[libpng16] Added tests for invalid palette index while reading and writing

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(work in progress, the latter isn't finished).
This commit is contained in:
Glenn Randers-Pehrson 2012-03-01 21:39:29 -06:00
parent cb129a6234
commit 363ae65e2b
7 changed files with 126 additions and 37 deletions
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2
ANNOUNCE
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@ -250,6 +250,8 @@ Version 1.6.0beta15 [March 2, 2012]
allow the error numbers in pngstest to be tuned and checked. makepng
also allows generation of images with extra chunks, although this is
still work-in-progress.
Added tests for invalid palette index while reading and writing (work in
progress, the latter isn't finished).
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit

2
CHANGES
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@ -4002,6 +4002,8 @@ Version 1.6.0beta15 [March 2, 2012]
allow the error numbers in pngstest to be tuned and checked. makepng
also allows generation of images with extra chunks, although this is
still work-in-progress.
Added tests for invalid palette index while reading and writing (work in
progress, the latter isn't finished).
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit

124
pngrtran.c
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@ -2294,32 +2294,104 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
png_do_unpack(row_info, png_ptr->row_buf + 1);
#endif
/* Added at libpng-1.6.0 */
#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
/* To do: Fix does not check sub-8-bit rows that have not been unpacked. */
if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
row_info->bit_depth == 8)
if (png_ptr->num_palette < (1 << png_ptr->bit_depth))
{
if ((png_ptr->interlaced && png_ptr->pass == 6) ||
(!png_ptr->interlaced && png_ptr->pass == 0))
{
png_uint_32 i;
png_bytep rp = png_ptr->row_buf+1; /* +1 to skip the filter byte */
for (i = 0; i <= row_info->rowbytes; i++)
{
if (*rp >= png_ptr->num_palette)
{
/* Should this be a benign error instead of a warning? */
png_warning(png_ptr,"Found invalid palette index");
break;
}
rp++;
}
}
}
#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
/* Added at libpng-1.5.10 */
if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
{
if (png_ptr->num_palette < (1 << png_ptr->bit_depth) &&
((png_ptr->interlaced && png_ptr->pass == 6) ||
(!png_ptr->interlaced && png_ptr->pass == 0)))
{
png_bytep rp = png_ptr->row_buf + 1 + row_info->rowbytes;
int index, padding;
switch (row_info->bit_depth)
{
case 1:
{
/* in this case, all bytes must be 0 so we don't need
* to unpack the pixels except for the rightmost one.
*/
padding = 8*row_info->rowbytes - png_ptr->width;
for (; rp > png_ptr->row_buf; rp--)
{
if (*rp >> padding != 0)
png_ptr->num_palette_max = 1;
padding = 0;
}
break;
}
case 2:
{
padding = 2*(4*row_info->rowbytes - png_ptr->width);
for (; rp > png_ptr->row_buf; rp--)
{
index = ((*rp >> padding) & 0x03);
if (index > png_ptr->num_palette_max)
png_ptr->num_palette_max = index;
index = (((*rp >> padding) >> 2) & 0x03);
if (index > png_ptr->num_palette_max)
png_ptr->num_palette_max = index;
index = (((*rp >> padding) >> 4) & 0x03);
if (index > png_ptr->num_palette_max)
png_ptr->num_palette_max = index;
index = (((*rp >> padding) >> 6) & 0x03);
if (index > png_ptr->num_palette_max)
png_ptr->num_palette_max = index;
padding = 0;
}
break;
}
case 4:
{
padding = 4*(2*row_info->rowbytes - png_ptr->width);
for (; rp > png_ptr->row_buf; rp--)
{
index = ((*rp >> padding) & 0x0f);
if (index > png_ptr->num_palette_max)
png_ptr->num_palette_max = index;
index = (((*rp >> padding) >> 4) & 0x0f);
if (index > png_ptr->num_palette_max)
png_ptr->num_palette_max = index;
padding = 0;
}
break;
}
case 8:
{
for (; rp > png_ptr->row_buf; rp--)
{
if (*rp >= png_ptr->num_palette_max)
png_ptr->num_palette_max = *rp;
}
break;
}
}
}
}
#endif
#ifdef PNG_READ_BGR_SUPPORTED

13
pngstruct.h
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@ -123,6 +123,12 @@ struct png_struct_def
png_uint_32 crc; /* current chunk CRC value */
png_colorp palette; /* palette from the input file */
png_uint_16 num_palette; /* number of color entries in palette */
/* Added at libpng-1.5.10 */
#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
png_uint_16 num_palette_max; /* maximum palette index found in IDAT */
#endif
png_uint_16 num_trans; /* number of transparency values */
png_byte compression; /* file compression type (always 0) */
png_byte filter; /* file filter type (always 0) */
@ -215,13 +221,6 @@ struct png_struct_def
int process_mode; /* what push library is currently doing */
int cur_palette; /* current push library palette index */
# ifdef PNG_TEXT_SUPPORTED
png_size_t current_text_size; /* current size of text input data */
png_size_t current_text_left; /* how much text left to read in input */
png_charp current_text; /* current text chunk buffer */
png_charp current_text_ptr; /* current location in current_text */
# endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)

7
pngwrite.c
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@ -731,12 +731,15 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
}
#endif
#if 0 /* To do: implement png_do_check_palette_indexes() */
/* Added at libpng-1.5.10 */
#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
/* Check for out-of-range palette index */
#if 0 /* To do: implement png_do_check_palette_indexes() */
if (png_ptr->num_palette < (1 << png_ptr->bit_depth))
png_do_check_palette_indexes(&row_info, png_ptr->row_buf + 1,
png_ptr->num_palette_max);
if (png_ptr->num_palette_max > num_palette + 1)
#endif
if (png_ptr->num_palette_max > png_ptr->num_palette + 1)
png_warning(png_ptr, "Palette index exceeded num_palette");
#endif

10
scripts/pnglibconf.dfa
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@ -586,7 +586,15 @@ option WRITE_COMPRESSED_TEXT enables WRITE_TEXT
option INFO_IMAGE
# Simplified API options
# added at libpng-1.5.10
# Turn this off to disable warning about invalid palette index and
# leave the num_palette_max member out of the png structure.
option CHECK_FOR_INVALID_INDEX
option READ_CHECK_FOR_INVALID_INDEX requires READ CHECK_FOR_INVALID_INDEX
option WRITE_CHECK_FOR_INVALID_INDEX requires WRITE CHECK_FOR_INVALID_INDEX
# Simplified API options (added at libpng-1.6.0)
# Read:
option SIMPLIFIED_READ requires SEQUENTIAL_READ READ_TRANSFORMS SETJMP
option SIMPLIFIED_READ enables READ_EXPAND READ_16BIT READ_EXPAND_16

5
scripts/pnglibconf.h.prebuilt
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@ -3,7 +3,7 @@
/* pnglibconf.h - library build configuration */
/* Libpng 1.6.0beta15 - February 27, 2012 */
/* Libpng 1.6.0beta15 - March 1, 2012 */
/* Copyright (c) 1998-2012 Glenn Randers-Pehrson */
@ -41,6 +41,7 @@
#define PNG_bKGD_SUPPORTED
#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
#define PNG_CHECK_cHRM_SUPPORTED
#define PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
#define PNG_cHRM_SUPPORTED
#define PNG_CONSOLE_IO_SUPPORTED
#define PNG_CONVERT_tIME_SUPPORTED
@ -72,6 +73,7 @@
#define PNG_READ_BACKGROUND_SUPPORTED
#define PNG_READ_BGR_SUPPORTED
#define PNG_READ_bKGD_SUPPORTED
#define PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
#define PNG_READ_cHRM_SUPPORTED
#define PNG_READ_COMPOSITE_NODIV_SUPPORTED
#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
@ -149,6 +151,7 @@
#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
#define PNG_WRITE_BGR_SUPPORTED
#define PNG_WRITE_bKGD_SUPPORTED
#define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
#define PNG_WRITE_cHRM_SUPPORTED
#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED