[master] Moved reading of file signature into png_read_sig (Cosmin)
diff --git a/CHANGES b/CHANGES
index a3168ed..4691289 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2702,13 +2702,9 @@
version 1.4.5rc02 [November 20, 2010]
Removed some extraneous parentheses that appeared in pngrutil.c of
- libpng-1.4.3bet01
-
-version 1.4.4-optipng [November 14, 2010]
- Fixed atomicity of chunk header serialization (Cosmin)
- Added test for io_state in pngtest.c (Cosmin)
- Moved reading of file signature into png_read_sig (Cosmin)
+ libpng-1.4.3bet01 (Cosmin)
Revised png_get_uint_32, png_get_int_32, png_get_uint_16 (Cosmin)
+ Moved reading of file signature into png_read_sig (Cosmin)
*/ }
#endif
diff --git a/png.h b/png.h
index 17b6e68..973b87d 100644
--- a/png.h
+++ b/png.h
@@ -2649,11 +2649,12 @@
((png_uint_32)(*((buf) + 2)) << 8) + \
((png_uint_32)(*((buf) + 3))))
# define png_get_uint_16(buf) \
- (((png_uint_32)(*(buf)) << 8) + \
- ((png_uint_32)(*((buf) + 1))))
+ ((png_uint_16) \
+ (((unsigned int)(*(buf)) << 8) + \
+ ((unsigned int)(*((buf) + 1)))))
# define png_get_int_32(buf) \
((png_int_32)((*(buf) & 0x80) \
- ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffff)+1)) \
+ ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
: (png_int_32)png_get_uint_32(buf)))
#else
PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
diff --git a/pngread.c b/pngread.c
index 92060d2..bc2b284 100644
--- a/pngread.c
+++ b/pngread.c
@@ -214,35 +214,13 @@
png_read_info(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_info");
-
+
if (png_ptr == NULL || info_ptr == NULL)
return;
-
- /* If we haven't checked all of the PNG signature bytes, do so now. */
- if (png_ptr->sig_bytes < 8)
- {
- png_size_t num_checked = png_ptr->sig_bytes,
- num_to_check = 8 - num_checked;
-#ifdef PNG_IO_STATE_SUPPORTED
- png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
-#endif
-
- png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
- png_ptr->sig_bytes = 8;
-
- if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
- {
- if (num_checked < 4 &&
- png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
- png_error(png_ptr, "Not a PNG file");
- else
- png_error(png_ptr, "PNG file corrupted by ASCII conversion");
- }
- if (num_checked < 3)
- png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
- }
-
+ /* Read and check the PNG file signature. */
+ png_read_sig(png_ptr, info_ptr);
+
for (;;)
{
PNG_IHDR;
@@ -426,7 +404,7 @@
png_read_update_info(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_update_info");
-
+
if (png_ptr == NULL)
return;
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
@@ -448,7 +426,7 @@
png_start_read_image(png_structp png_ptr)
{
png_debug(1, "in png_start_read_image");
-
+
if (png_ptr == NULL)
return;
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
@@ -465,10 +443,10 @@
0xff};
PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
int ret;
-
+
if (png_ptr == NULL)
return;
-
+
png_debug2(1, "in png_read_row (row %lu, pass %d)",
(unsigned long) png_ptr->row_number, png_ptr->pass);
@@ -724,7 +702,7 @@
png_bytepp dp;
png_debug(1, "in png_read_rows");
-
+
if (png_ptr == NULL)
return;
rp = row;
@@ -775,7 +753,7 @@
png_bytepp rp;
png_debug(1, "in png_read_image");
-
+
if (png_ptr == NULL)
return;
@@ -813,7 +791,7 @@
png_read_end(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_end");
-
+
if (png_ptr == NULL)
return;
png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
@@ -993,7 +971,7 @@
#endif
png_debug(1, "in png_destroy_read_struct");
-
+
if (png_ptr_ptr != NULL)
png_ptr = *png_ptr_ptr;
if (png_ptr == NULL)
@@ -1069,7 +1047,7 @@
#endif
png_debug(1, "in png_read_destroy");
-
+
if (info_ptr != NULL)
png_info_destroy(png_ptr, info_ptr);
diff --git a/pngrutil.c b/pngrutil.c
index 1191c48..9856c1f 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -69,6 +69,39 @@
}
#endif /* PNG_USE_READ_MACROS */
+/* Read and check the PNG file signature */
+void /* PRIVATE */
+png_read_sig(png_structp png_ptr, png_infop info_ptr)
+{
+ png_size_t num_checked, num_to_check;
+
+ /* Exit if the user application does not expect a signature. */
+ if (png_ptr->sig_bytes >= 8)
+ return;
+
+ num_checked = png_ptr->sig_bytes;
+ num_to_check = 8 - num_checked;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
+#endif
+
+ /* The signature must be serialized in a single I/O call. */
+ png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
+ png_ptr->sig_bytes = 8;
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+ png_error(png_ptr, "Not a PNG file");
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ if (num_checked < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
/* Read the chunk header (length + type name).
* Put the type name into png_ptr->chunk_name, and return the length.
*/
@@ -79,32 +112,31 @@
png_uint_32 length;
#ifdef PNG_IO_STATE_SUPPORTED
- /* Inform the I/O callback that the chunk header is being read.
- * PNG_IO_CHUNK_HDR requires a single I/O call.
- */
png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
#endif
- /* Read the length and the chunk name */
+ /* Read the length and the chunk name.
+ * This must be performed in a single I/O call.
+ */
png_read_data(png_ptr, buf, 8);
length = png_get_uint_31(png_ptr, buf);
- /* Put the chunk name into png_ptr->chunk_name */
+ /* Put the chunk name into png_ptr->chunk_name. */
png_memcpy(png_ptr->chunk_name, buf + 4, 4);
png_debug2(0, "Reading %s chunk, length = %lu",
png_ptr->chunk_name, length);
- /* Reset the crc and run it over the chunk name */
+ /* Reset the crc and run it over the chunk name. */
png_reset_crc(png_ptr);
png_calculate_crc(png_ptr, png_ptr->chunk_name, 4);
- /* Check to see if chunk name is valid */
+ /* Check to see if chunk name is valid. */
png_check_chunk_name(png_ptr, png_ptr->chunk_name);
#ifdef PNG_IO_STATE_SUPPORTED
- /* Inform the I/O callback that chunk data will (possibly) be read.
- * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
+ /* It is unspecified how many I/O calls will be performed
+ * during the serialization of the chunk data.
*/
png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
#endif
@@ -185,11 +217,10 @@
}
#ifdef PNG_IO_STATE_SUPPORTED
- /* Inform the I/O callback that the chunk CRC is being read */
- /* PNG_IO_CHUNK_CRC requires the I/O to be done at once */
png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
#endif
+ /* The chunk CRC must be serialized in a single I/O call. */
png_read_data(png_ptr, crc_bytes, 4);
if (need_crc)
@@ -3108,17 +3139,10 @@
{
while (!png_ptr->idat_size)
{
- png_byte chunk_length[4];
-
png_crc_finish(png_ptr, 0);
-
- png_read_data(png_ptr, chunk_length, 4);
- png_ptr->idat_size = png_get_uint_31(png_ptr, chunk_length);
- png_reset_crc(png_ptr);
- png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+ png_ptr->idat_size = png_read_chunk_header(png_ptr);
if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
png_error(png_ptr, "Not enough image data");
-
}
png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
png_ptr->zstream.next_in = png_ptr->zbuf;
