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[libpng16] Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from

Browse Source 
pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
    now that png_ptr->buffer is inaccessible to applications, the special
    handling is no longer useful.
This commit is contained in:
Glenn Randers-Pehrson 2012-02-21 14:49:56 -06:00
parent 7d5bf79d88
commit 17ba5de88f
3 changed files with 15 additions and 550 deletions
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8
ANNOUNCE
View File

@ -1,5 +1,5 @@
Libpng 1.6.0beta13 - February 19, 2012
Libpng 1.6.0beta13 - February 21, 2012
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.
@ -219,7 +219,11 @@ Version 1.6.0beta12 [February 18, 2012]
on iCCP chunk length. Also removed spurious casts that may hide problems
on 16-bit systems.
Version 1.6.0beta13 [February 19, 2012]
Version 1.6.0beta13 [February 21, 2012]
Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from
pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
now that png_ptr->buffer is inaccessible to applications, the special
handling is no longer useful.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit

6
CHANGES
View File

@ -3970,7 +3970,11 @@ Version 1.6.0beta12 [February 18, 2012]
on iCCP chunk length. Also removed spurious casts that may hide problems
on 16-bit systems.
Version 1.6.0beta13 [February 19, 2012]
Version 1.6.0beta13 [February 21, 2012]
Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from
pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
now that png_ptr->buffer is inaccessible to applications, the special
handling is no longer useful.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit

551
pngpread.c
View File

@ -128,30 +128,6 @@ png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
break;
}
#ifdef PNG_READ_tEXt_SUPPORTED
case PNG_READ_tEXt_MODE:
{
png_push_read_tEXt(png_ptr, info_ptr);
break;
}
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
case PNG_READ_zTXt_MODE:
{
png_push_read_zTXt(png_ptr, info_ptr);
break;
}
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
case PNG_READ_iTXt_MODE:
{
png_push_read_iTXt(png_ptr, info_ptr);
break;
}
#endif
case PNG_SKIP_MODE:
{
png_push_crc_finish(png_ptr);
@ -543,7 +519,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
return;
}
png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
@ -556,7 +532,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
return;
}
png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
@ -569,7 +545,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
return;
}
png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
@ -580,7 +556,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
png_push_save_buffer(png_ptr);
return;
}
png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
}
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
@ -1264,525 +1240,6 @@ png_read_push_finish_row(png_structrp png_ptr)
#endif /* PNG_READ_INTERLACING_SUPPORTED */
}
#ifdef PNG_READ_tEXt_SUPPORTED
void /* PRIVATE */
png_push_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32
length)
{
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
{
PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
png_error(png_ptr, "Out of place tEXt");
/* NOT REACHED */
}
#ifdef PNG_MAX_MALLOC_64K
png_ptr->skip_length = 0; /* This may not be necessary */
if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
{
png_warning(png_ptr, "tEXt chunk too large to fit in memory");
png_ptr->skip_length = length - (png_uint_32)65535L;
length = (png_uint_32)65535L;
}
#endif
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
(png_size_t)(length + 1));
png_ptr->current_text[length] = '\0';
png_ptr->current_text_ptr = png_ptr->current_text;
png_ptr->current_text_size = (png_size_t)length;
png_ptr->current_text_left = (png_size_t)length;
png_ptr->process_mode = PNG_READ_tEXt_MODE;
}
void /* PRIVATE */
png_push_read_tEXt(png_structrp png_ptr, png_inforp info_ptr)
{
if (png_ptr->buffer_size && png_ptr->current_text_left)
{
png_size_t text_size;
if (png_ptr->buffer_size < png_ptr->current_text_left)
text_size = png_ptr->buffer_size;
else
text_size = png_ptr->current_text_left;
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
png_ptr->current_text_left -= text_size;
png_ptr->current_text_ptr += text_size;
}
if (!(png_ptr->current_text_left))
{
png_textp text_ptr;
png_charp text;
png_charp key;
int ret;
if (png_ptr->buffer_size < 4)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_crc_finish(png_ptr);
#ifdef PNG_MAX_MALLOC_64K
if (png_ptr->skip_length)
return;
#endif
key = png_ptr->current_text;
for (text = key; *text; text++)
/* Empty loop */ ;
if (text < key + png_ptr->current_text_size)
text++;
text_ptr = (png_textp)png_malloc(png_ptr, png_sizeof(png_text));
text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
text_ptr->key = key;
text_ptr->itxt_length = 0;
text_ptr->lang = NULL;
text_ptr->lang_key = NULL;
text_ptr->text = text;
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
png_free(png_ptr, key);
png_free(png_ptr, text_ptr);
png_ptr->current_text = NULL;
if (ret)
png_warning(png_ptr, "Insufficient memory to store text chunk");
}
}
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
void /* PRIVATE */
png_push_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32
length)
{
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
{
PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
png_error(png_ptr, "Out of place zTXt");
/* NOT REACHED */
}
#ifdef PNG_MAX_MALLOC_64K
/* We can't handle zTXt chunks > 64K, since we don't have enough space
* to be able to store the uncompressed data. Actually, the threshold
* is probably around 32K, but it isn't as definite as 64K is.
*/
if (length > (png_uint_32)65535L)
{
png_warning(png_ptr, "zTXt chunk too large to fit in memory");
png_push_crc_skip(png_ptr, length);
return;
}
#endif
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
(png_size_t)(length + 1));
png_ptr->current_text[length] = '\0';
png_ptr->current_text_ptr = png_ptr->current_text;
png_ptr->current_text_size = (png_size_t)length;
png_ptr->current_text_left = (png_size_t)length;
png_ptr->process_mode = PNG_READ_zTXt_MODE;
}
void /* PRIVATE */
png_push_read_zTXt(png_structrp png_ptr, png_inforp info_ptr)
{
if (png_ptr->buffer_size && png_ptr->current_text_left)
{
png_size_t text_size;
if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
text_size = png_ptr->buffer_size;
else
text_size = png_ptr->current_text_left;
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
png_ptr->current_text_left -= text_size;
png_ptr->current_text_ptr += text_size;
}
if (!(png_ptr->current_text_left))
{
png_textp text_ptr;
png_charp text;
png_charp key;
int ret;
png_size_t text_size, key_size;
if (png_ptr->buffer_size < 4)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_crc_finish(png_ptr);
key = png_ptr->current_text;
for (text = key; *text; text++)
/* Empty loop */ ;
/* zTXt can't have zero text */
if (text >= key + png_ptr->current_text_size)
{
png_ptr->current_text = NULL;
png_free(png_ptr, key);
return;
}
text++;
if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
{
png_ptr->current_text = NULL;
png_free(png_ptr, key);
return;
}
text++;
png_ptr->zstream.next_in = (png_bytep)text;
png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
(text - key));
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
key_size = text - key;
text_size = 0;
text = NULL;
ret = Z_STREAM_END;
while (png_ptr->zstream.avail_in)
{
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
if (ret != Z_OK && ret != Z_STREAM_END)
{
inflateReset(&png_ptr->zstream);
png_ptr->zstream.avail_in = 0;
png_ptr->current_text = NULL;
png_free(png_ptr, key);
png_free(png_ptr, text);
return;
}
if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
{
if (text == NULL)
{
text = (png_charp)png_malloc(png_ptr,
(png_ptr->zbuf_size
- png_ptr->zstream.avail_out + key_size + 1));
png_memcpy(text + key_size, png_ptr->zbuf,
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
png_memcpy(text, key, key_size);
text_size = key_size + png_ptr->zbuf_size -
png_ptr->zstream.avail_out;
*(text + text_size) = '\0';
}
else
{
png_charp tmp;
tmp = text;
text = (png_charp)png_malloc(png_ptr, text_size +
(png_ptr->zbuf_size
- png_ptr->zstream.avail_out + 1));
png_memcpy(text, tmp, text_size);
png_free(png_ptr, tmp);
png_memcpy(text + text_size, png_ptr->zbuf,
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
*(text + text_size) = '\0';
}
if (ret != Z_STREAM_END)
{
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
}
}
else
{
break;
}
if (ret == Z_STREAM_END)
break;
}
inflateReset(&png_ptr->zstream);
png_ptr->zstream.avail_in = 0;
if (ret != Z_STREAM_END)
{
png_ptr->current_text = NULL;
png_free(png_ptr, key);
png_free(png_ptr, text);
return;
}
png_ptr->current_text = NULL;
png_free(png_ptr, key);
key = text;
text += key_size;
text_ptr = (png_textp)png_malloc(png_ptr,
png_sizeof(png_text));
text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
text_ptr->key = key;
text_ptr->itxt_length = 0;
text_ptr->lang = NULL;
text_ptr->lang_key = NULL;
text_ptr->text = text;
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
png_free(png_ptr, key);
png_free(png_ptr, text_ptr);
if (ret)
png_warning(png_ptr, "Insufficient memory to store text chunk");
}
}
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
void /* PRIVATE */
png_push_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32
length)
{
if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
{
PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
png_error(png_ptr, "Out of place iTXt");
/* NOT REACHED */
}
#ifdef PNG_MAX_MALLOC_64K
png_ptr->skip_length = 0; /* This may not be necessary */
if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
{
png_warning(png_ptr, "iTXt chunk too large to fit in memory");
png_ptr->skip_length = length - (png_uint_32)65535L;
length = (png_uint_32)65535L;
}
#endif
png_ptr->current_text = (png_charp)png_malloc(png_ptr,
(png_size_t)(length + 1));
png_ptr->current_text[length] = '\0';
png_ptr->current_text_ptr = png_ptr->current_text;
png_ptr->current_text_size = (png_size_t)length;
png_ptr->current_text_left = (png_size_t)length;
png_ptr->process_mode = PNG_READ_iTXt_MODE;
}
void /* PRIVATE */
png_push_read_iTXt(png_structrp png_ptr, png_inforp info_ptr)
{
if (png_ptr->buffer_size && png_ptr->current_text_left)
{
png_size_t text_size;
if (png_ptr->buffer_size < png_ptr->current_text_left)
text_size = png_ptr->buffer_size;
else
text_size = png_ptr->current_text_left;
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
png_ptr->current_text_left -= text_size;
png_ptr->current_text_ptr += text_size;
}
if (!(png_ptr->current_text_left))
{
png_textp text_ptr;
png_charp key;
int comp_flag;
png_charp lang;
png_charp lang_key;
png_charp text;
int ret;
if (png_ptr->buffer_size < 4)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_crc_finish(png_ptr);
#ifdef PNG_MAX_MALLOC_64K
if (png_ptr->skip_length)
return;
#endif
key = png_ptr->current_text;
for (lang = key; *lang; lang++)
/* Empty loop */ ;
if (lang < key + png_ptr->current_text_size - 3)
lang++;
comp_flag = *lang++;
lang++; /* Skip comp_type, always zero */
for (lang_key = lang; *lang_key; lang_key++)
/* Empty loop */ ;
lang_key++; /* Skip NUL separator */
text=lang_key;
if (lang_key < key + png_ptr->current_text_size - 1)
{
for (; *text; text++)
/* Empty loop */ ;
}
if (text < key + png_ptr->current_text_size)
text++;
text_ptr = (png_textp)png_malloc(png_ptr,
png_sizeof(png_text));
text_ptr->compression = comp_flag + 2;
text_ptr->key = key;
text_ptr->lang = lang;
text_ptr->lang_key = lang_key;
text_ptr->text = text;
text_ptr->text_length = 0;
text_ptr->itxt_length = png_strlen(text);
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
png_ptr->current_text = NULL;
png_free(png_ptr, text_ptr);
if (ret)
png_warning(png_ptr, "Insufficient memory to store iTXt chunk");
}
}
#endif
/* This function is called when we haven't found a handler for this
* chunk. If there isn't a problem with the chunk itself (ie a bad chunk
* name or a critical chunk), the chunk is (currently) silently ignored.
*/
void /* PRIVATE */
png_push_handle_unknown(png_structrp png_ptr, png_inforp info_ptr, png_uint_32
length)
{
png_uint_32 skip = 0;
png_uint_32 chunk_name = png_ptr->chunk_name;
if (PNG_CHUNK_CRITICAL(chunk_name))
{
#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
PNG_HANDLE_CHUNK_ALWAYS
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
&& png_ptr->read_user_chunk_fn == NULL
#endif
)
#endif
png_chunk_error(png_ptr, "unknown critical chunk");
PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
}
#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
/* TODO: the code below is apparently just using the
* png_struct::unknown_chunk member as a temporarily variable, it should be
* possible to eliminate both it and the temporary buffer.
*/
if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
{
#ifdef PNG_MAX_MALLOC_64K
if (length > 65535)
{
png_warning(png_ptr, "unknown chunk too large to fit in memory");
skip = length - 65535;
length = 65535;
}
#endif
/* This is just a record for the user; libpng doesn't use the character
* form of the name.
*/
PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
/* The following cast should be safe because of the check above. */
png_ptr->unknown_chunk.size = (png_size_t)length;
if (length == 0)
png_ptr->unknown_chunk.data = NULL;
else
{
png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
png_ptr->unknown_chunk.size);
png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data,
png_ptr->unknown_chunk.size);
}
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
if (png_ptr->read_user_chunk_fn != NULL)
{
/* Callback to user unknown chunk handler */
int ret;
ret = (*(png_ptr->read_user_chunk_fn))
(png_ptr, &png_ptr->unknown_chunk);
if (ret < 0)
png_chunk_error(png_ptr, "error in user chunk");
if (ret == 0)
{
if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
PNG_HANDLE_CHUNK_ALWAYS)
png_chunk_error(png_ptr, "unknown critical chunk");
png_set_unknown_chunks(png_ptr, info_ptr,
&png_ptr->unknown_chunk, 1);
}
}
else
#endif
png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
png_free(png_ptr, png_ptr->unknown_chunk.data);
png_ptr->unknown_chunk.data = NULL;
}
else
#endif
skip=length;
png_push_crc_skip(png_ptr, skip);
}
void /* PRIVATE */
png_push_have_info(png_structrp png_ptr, png_inforp info_ptr)
{