/* pngpread.c - read a png file in push mode
*
- * Last changed in libpng 1.6.11 [June 5, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Copyright (c) 1998-2002,2004,2006-2015 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.)
*
#define PNG_READ_SIG_MODE 0
#define PNG_READ_CHUNK_MODE 1
#define PNG_READ_IDAT_MODE 2
-#define PNG_SKIP_MODE 3
#define PNG_READ_tEXt_MODE 4
#define PNG_READ_zTXt_MODE 5
#define PNG_READ_DONE_MODE 6
#define PNG_READ_iTXt_MODE 7
#define PNG_ERROR_MODE 8
+#define PNG_PUSH_SAVE_BUFFER_IF_FULL \
+if (png_ptr->push_length + 4 > png_ptr->buffer_size) \
+ { png_push_save_buffer(png_ptr); return; }
+#define PNG_PUSH_SAVE_BUFFER_IF_LT(N) \
+if (png_ptr->buffer_size < N) \
+ { png_push_save_buffer(png_ptr); return; }
+
void PNGAPI
png_process_data(png_structrp png_ptr, png_inforp info_ptr,
png_bytep buffer, png_size_t buffer_size)
{
if (png_ptr != NULL)
{
- /* It's easiest for the caller if we do the save, then the caller doesn't
+ /* It's easiest for the caller if we do the save; then the caller doesn't
* have to supply the same data again:
*/
if (save != 0)
png_uint_32 PNGAPI
png_process_data_skip(png_structrp png_ptr)
{
- png_uint_32 remaining = 0;
-
- if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE &&
- png_ptr->skip_length > 0)
- {
- /* At the end of png_process_data the buffer size must be 0 (see the loop
- * above) so we can detect a broken call here:
- */
- if (png_ptr->buffer_size != 0)
- png_error(png_ptr,
- "png_process_data_skip called inside png_process_data");
-
- /* If is impossible for there to be a saved buffer at this point -
- * otherwise we could not be in SKIP mode. This will also happen if
- * png_process_skip is called inside png_process_data (but only very
- * rarely.)
- */
- if (png_ptr->save_buffer_size != 0)
- png_error(png_ptr, "png_process_data_skip called with saved data");
-
- remaining = png_ptr->skip_length;
- png_ptr->skip_length = 0;
- png_ptr->process_mode = PNG_READ_CHUNK_MODE;
- }
-
- return remaining;
+ /* TODO: Deprecate and remove this API.
+ * Somewhere the implementation of this seems to have been lost,
+ * or abandoned. It was only to support some internal back-door access
+ * to png_struct) in libpng-1.4.x.
+ */
+ png_app_warning(png_ptr,
+"png_process_data_skip is not implemented in any current version of libpng");
+ return 0;
}
/* What we do with the incoming data depends on what we were previously
break;
}
- case PNG_SKIP_MODE:
- {
- png_push_crc_finish(png_ptr);
- break;
- }
-
default:
{
png_ptr->buffer_size = 0;
void /* PRIVATE */
png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
{
- png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */
- num_to_check = 8 - num_checked;
+ png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */
+ num_to_check = 8 - num_checked;
if (png_ptr->buffer_size < num_to_check)
{
int keep; /* unknown handling method */
#endif
- /* First we make sure we have enough data for the 4 byte chunk name
- * and the 4 byte chunk length before proceeding with decoding the
+ /* First we make sure we have enough data for the 4-byte chunk name
+ * and the 4-byte chunk length before proceeding with decoding the
* chunk data. To fully decode each of these chunks, we also make
- * sure we have enough data in the buffer for the 4 byte CRC at the
+ * sure we have enough data in the buffer for the 4-byte CRC at the
* end of every chunk (except IDAT, which is handled separately).
*/
- if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+ if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
{
png_byte chunk_length[4];
png_byte chunk_tag[4];
- if (png_ptr->buffer_size < 8)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_LT(8)
png_push_fill_buffer(png_ptr, chunk_length, 4);
png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
png_reset_crc(png_ptr);
if (chunk_name == png_IDAT)
{
- if (png_ptr->mode & PNG_AFTER_IDAT)
+ if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
/* If we reach an IDAT chunk, this means we have read all of the
* header chunks, and we can start reading the image (or if this
* is called after the image has been read - we have an error).
*/
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
png_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
- !(png_ptr->mode & PNG_HAVE_PLTE))
+ (png_ptr->mode & PNG_HAVE_PLTE) == 0)
png_error(png_ptr, "Missing PLTE before IDAT");
png_ptr->mode |= PNG_HAVE_IDAT;
png_ptr->process_mode = PNG_READ_IDAT_MODE;
- if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+ if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0)
if (png_ptr->push_length == 0)
return;
- if (png_ptr->mode & PNG_AFTER_IDAT)
+ if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
png_benign_error(png_ptr, "Too many IDATs found");
}
if (png_ptr->push_length != 13)
png_error(png_ptr, "Invalid IHDR length");
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
}
else if (chunk_name == png_IEND)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
png_ptr->process_mode = PNG_READ_DONE_MODE;
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
if (chunk_name == png_PLTE)
else if (chunk_name == png_PLTE)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_gAMA_SUPPORTED
else if (png_ptr->chunk_name == png_gAMA)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_sBIT_SUPPORTED
else if (png_ptr->chunk_name == png_sBIT)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_cHRM_SUPPORTED
else if (png_ptr->chunk_name == png_cHRM)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_sRGB_SUPPORTED
else if (chunk_name == png_sRGB)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_iCCP_SUPPORTED
else if (png_ptr->chunk_name == png_iCCP)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_sPLT_SUPPORTED
else if (chunk_name == png_sPLT)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_tRNS_SUPPORTED
else if (chunk_name == png_tRNS)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_bKGD_SUPPORTED
else if (chunk_name == png_bKGD)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_hIST_SUPPORTED
else if (chunk_name == png_hIST)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_pHYs_SUPPORTED
else if (chunk_name == png_pHYs)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_oFFs_SUPPORTED
else if (chunk_name == png_oFFs)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
else if (chunk_name == png_pCAL)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_sCAL_SUPPORTED
else if (chunk_name == png_sCAL)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_tIME_SUPPORTED
else if (chunk_name == png_tIME)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_tEXt_SUPPORTED
else if (chunk_name == png_tEXt)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_zTXt_SUPPORTED
else if (chunk_name == png_zTXt)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
}
#ifdef PNG_READ_iTXt_SUPPORTED
else if (chunk_name == png_iTXt)
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
else
{
- if (png_ptr->push_length + 4 > png_ptr->buffer_size)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
PNG_HANDLE_CHUNK_AS_DEFAULT);
}
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
}
-void /* PRIVATE */
-png_push_crc_skip(png_structrp png_ptr, png_uint_32 skip)
-{
- png_ptr->process_mode = PNG_SKIP_MODE;
- png_ptr->skip_length = skip;
-}
-
-void /* PRIVATE */
-png_push_crc_finish(png_structrp png_ptr)
-{
- if (png_ptr->skip_length && png_ptr->save_buffer_size)
- {
- png_size_t save_size = png_ptr->save_buffer_size;
- png_uint_32 skip_length = png_ptr->skip_length;
-
- /* We want the smaller of 'skip_length' and 'save_buffer_size', but
- * they are of different types and we don't know which variable has the
- * fewest bits. Carefully select the smaller and cast it to the type of
- * the larger - this cannot overflow. Do not cast in the following test
- * - it will break on either 16 or 64 bit platforms.
- */
- if (skip_length < save_size)
- save_size = (png_size_t)skip_length;
-
- else
- skip_length = (png_uint_32)save_size;
-
- png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
-
- png_ptr->skip_length -= skip_length;
- png_ptr->buffer_size -= save_size;
- png_ptr->save_buffer_size -= save_size;
- png_ptr->save_buffer_ptr += save_size;
- }
- if (png_ptr->skip_length && png_ptr->current_buffer_size)
- {
- png_size_t save_size = png_ptr->current_buffer_size;
- png_uint_32 skip_length = png_ptr->skip_length;
-
- /* We want the smaller of 'skip_length' and 'current_buffer_size', here,
- * the same problem exists as above and the same solution.
- */
- if (skip_length < save_size)
- save_size = (png_size_t)skip_length;
-
- else
- skip_length = (png_uint_32)save_size;
-
- png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
-
- png_ptr->skip_length -= skip_length;
- png_ptr->buffer_size -= save_size;
- png_ptr->current_buffer_size -= save_size;
- png_ptr->current_buffer_ptr += save_size;
- }
- if (!png_ptr->skip_length)
- {
- if (png_ptr->buffer_size < 4)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_crc_finish(png_ptr, 0);
- png_ptr->process_mode = PNG_READ_CHUNK_MODE;
- }
-}
-
void PNGCBAPI
png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
{
return;
ptr = buffer;
- if (png_ptr->save_buffer_size)
+ if (png_ptr->save_buffer_size != 0)
{
png_size_t save_size;
png_ptr->save_buffer_size -= save_size;
png_ptr->save_buffer_ptr += save_size;
}
- if (length && png_ptr->current_buffer_size)
+ if (length != 0 && png_ptr->current_buffer_size != 0)
{
png_size_t save_size;
void /* PRIVATE */
png_push_save_buffer(png_structrp png_ptr)
{
- if (png_ptr->save_buffer_size)
+ if (png_ptr->save_buffer_size != 0)
{
if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
{
void /* PRIVATE */
png_push_read_IDAT(png_structrp png_ptr)
{
- if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+ if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
{
png_byte chunk_length[4];
png_byte chunk_tag[4];
/* TODO: this code can be commoned up with the same code in push_read */
- if (png_ptr->buffer_size < 8)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
+ PNG_PUSH_SAVE_BUFFER_IF_LT(8)
png_push_fill_buffer(png_ptr, chunk_length, 4);
png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
png_reset_crc(png_ptr);
{
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
- if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
png_error(png_ptr, "Not enough compressed data");
return;
png_ptr->idat_size = png_ptr->push_length;
}
- if (png_ptr->idat_size && png_ptr->save_buffer_size)
+ if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0)
{
png_size_t save_size = png_ptr->save_buffer_size;
png_uint_32 idat_size = png_ptr->idat_size;
* are of different types and we don't know which variable has the fewest
* bits. Carefully select the smaller and cast it to the type of the
* larger - this cannot overflow. Do not cast in the following test - it
- * will break on either 16 or 64 bit platforms.
+ * will break on either 16-bit or 64-bit platforms.
*/
if (idat_size < save_size)
save_size = (png_size_t)idat_size;
png_ptr->save_buffer_ptr += save_size;
}
- if (png_ptr->idat_size && png_ptr->current_buffer_size)
+ if (png_ptr->idat_size != 0 && png_ptr->current_buffer_size != 0)
{
png_size_t save_size = png_ptr->current_buffer_size;
png_uint_32 idat_size = png_ptr->idat_size;
png_ptr->current_buffer_size -= save_size;
png_ptr->current_buffer_ptr += save_size;
}
- if (!png_ptr->idat_size)
- {
- if (png_ptr->buffer_size < 4)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
+ if (png_ptr->idat_size == 0)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_LT(4)
png_crc_finish(png_ptr, 0);
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
png_ptr->mode |= PNG_AFTER_IDAT;
* or the stream marked as finished.
*/
while (png_ptr->zstream.avail_in > 0 &&
- !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+ (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
{
int ret;
* change the current behavior (see comments in inflate.c
* for why this doesn't happen at present with zlib 1.2.5).
*/
- ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);
+ ret = PNG_INFLATE(png_ptr, Z_SYNC_FLUSH);
/* Check for any failure before proceeding. */
if (ret != Z_OK && ret != Z_STREAM_END)
memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
- if (png_ptr->transformations)
+ if (png_ptr->transformations != 0)
png_do_read_transformations(png_ptr, &row_info);
#endif
#ifdef PNG_READ_INTERLACING_SUPPORTED
/* Expand interlaced rows to full size */
- if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
{
if (png_ptr->pass < 6)
png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
}
}
else
+#endif
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
void /* PRIVATE */
png_read_push_finish_row(png_structrp png_ptr)
{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
/* Start of interlace block */
if (png_ptr->row_number < png_ptr->num_rows)
return;
- if (png_ptr->interlaced)
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced != 0)
{
png_ptr->row_number = 0;
memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
png_pass_start[png_ptr->pass]) /
png_pass_inc[png_ptr->pass];
- if (png_ptr->transformations & PNG_INTERLACE)
+ if ((png_ptr->transformations & PNG_INTERLACE) != 0)
break;
png_ptr->num_rows = (png_ptr->height +
} while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
}
+#endif /* READ_INTERLACING */
}
void /* PRIVATE */
(int)png_ptr->pass);
}
+#ifdef PNG_READ_INTERLACING_SUPPORTED
void PNGAPI
png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row,
png_const_bytep new_row)
if (new_row != NULL)
png_combine_row(png_ptr, old_row, 1/*blocky display*/);
}
+#endif /* READ_INTERLACING */
void PNGAPI
png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr,
return png_ptr->io_ptr;
}
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PROGRESSIVE_READ */