/* pngpread.c - read a png file in push mode
*
- * libpng 1.0.1
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 15, 1998
+ * Last changed in libpng 1.6.0 [February 14, 2013]
+ * Copyright (c) 1998-2013 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.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
*/
-#define PNG_INTERNAL
-#include "png.h"
+#include "pngpriv.h"
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-void
-png_process_data(png_structp png_ptr, png_infop info_ptr,
- png_bytep buffer, png_size_t buffer_size)
+/* Push model modes */
+#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
+
+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 || info_ptr == NULL)
+ return;
+
png_push_restore_buffer(png_ptr, buffer, buffer_size);
while (png_ptr->buffer_size)
}
}
+png_size_t PNGAPI
+png_process_data_pause(png_structrp png_ptr, int save)
+{
+ if (png_ptr != NULL)
+ {
+ /* 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)
+ png_push_save_buffer(png_ptr);
+ else
+ {
+ /* This includes any pending saved bytes: */
+ png_size_t remaining = png_ptr->buffer_size;
+ png_ptr->buffer_size = 0;
+
+ /* So subtract the saved buffer size, unless all the data
+ * is actually 'saved', in which case we just return 0
+ */
+ if (png_ptr->save_buffer_size < remaining)
+ return remaining - png_ptr->save_buffer_size;
+ }
+ }
+
+ return 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;
+}
+
/* What we do with the incoming data depends on what we were previously
* doing before we ran out of data...
*/
-void
-png_process_some_data(png_structp png_ptr, png_infop info_ptr)
+void /* PRIVATE */
+png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
{
+ if (png_ptr == NULL)
+ return;
+
switch (png_ptr->process_mode)
{
case PNG_READ_SIG_MODE:
png_push_read_sig(png_ptr, info_ptr);
break;
}
+
case PNG_READ_CHUNK_MODE:
{
png_push_read_chunk(png_ptr, info_ptr);
break;
}
+
case PNG_READ_IDAT_MODE:
{
png_push_read_IDAT(png_ptr);
break;
}
-#if defined(PNG_READ_tEXt_SUPPORTED)
- case PNG_READ_tEXt_MODE:
- {
- png_push_read_tEXt(png_ptr, info_ptr);
- break;
- }
-#endif
-#if defined(PNG_READ_zTXt_SUPPORTED)
- case PNG_READ_zTXt_MODE:
- {
- png_push_read_zTXt(png_ptr, info_ptr);
- break;
- }
-#endif
+
case PNG_SKIP_MODE:
{
png_push_crc_finish(png_ptr);
break;
}
+
default:
{
png_ptr->buffer_size = 0;
/* Read any remaining signature bytes from the stream and compare them with
* the correct PNG signature. It is possible that this routine is called
- * with bytes already read from the signature, whether because they have been
- * checked by the calling application, or from multiple calls to this routine.
+ * with bytes already read from the signature, either because they have been
+ * checked by the calling application, or because of multiple calls to this
+ * routine.
*/
-void
-png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
+void /* PRIVATE */
+png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
{
png_size_t num_checked = png_ptr->sig_bytes,
num_to_check = 8 - num_checked;
num_to_check = png_ptr->buffer_size;
}
- png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
- num_to_check);
- png_ptr->sig_bytes += num_to_check;
+ png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
+ num_to_check);
+ png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
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");
}
}
}
-void
-png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
+void /* PRIVATE */
+png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
{
+ png_uint_32 chunk_name;
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ 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
* 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
* end of every chunk (except IDAT, which is handled separately).
*/
- if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER))
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
{
png_byte chunk_length[4];
+ png_byte chunk_tag[4];
if (png_ptr->buffer_size < 8)
{
}
png_push_fill_buffer(png_ptr, chunk_length, 4);
- png_ptr->push_length = png_get_uint_32(chunk_length);
+ png_ptr->push_length = 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->flags |= PNG_FLAG_HAVE_CHUNK_HEADER;
+ png_crc_read(png_ptr, chunk_tag, 4);
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
}
- if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
+ chunk_name = png_ptr->chunk_name;
+
+ if (chunk_name == png_IDAT)
{
+ if (png_ptr->mode & PNG_AFTER_IDAT)
+ 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))
+ 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_error(png_ptr, "Missing PLTE before IDAT");
+
+ png_ptr->mode |= PNG_HAVE_IDAT;
+
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+ if (png_ptr->push_length == 0)
+ return;
+
+ if (png_ptr->mode & PNG_AFTER_IDAT)
+ png_benign_error(png_ptr, "Too many IDATs found");
+ }
+
+ if (chunk_name == png_IHDR)
+ {
+ 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);
png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
}
- else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+
+ else if (chunk_name == png_IEND)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
return;
}
- png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
+ png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
+
+ png_ptr->process_mode = PNG_READ_DONE_MODE;
+ png_push_have_end(png_ptr, info_ptr);
}
- else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
{
- /* 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_IDAT)
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
- if (png_ptr->push_length == 0)
- return;
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
+
+ if (chunk_name == png_PLTE)
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ }
- if (png_ptr->mode & PNG_AFTER_IDAT)
- png_error(png_ptr, "Too many IDAT's found");
+#endif
+ else if (chunk_name == png_PLTE)
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
}
+ png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
+ }
+ else if (chunk_name == png_IDAT)
+ {
png_ptr->idat_size = png_ptr->push_length;
- png_ptr->mode |= PNG_HAVE_IDAT;
png_ptr->process_mode = PNG_READ_IDAT_MODE;
png_push_have_info(png_ptr, info_ptr);
- png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
+ png_ptr->zstream.avail_out =
+ (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1;
png_ptr->zstream.next_out = png_ptr->row_buf;
return;
}
- else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+ else if (png_ptr->chunk_name == png_gAMA)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
return;
}
- png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
- png_ptr->process_mode = PNG_READ_DONE_MODE;
- png_push_have_end(png_ptr, info_ptr);
+ png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
}
-#if defined(PNG_READ_gAMA_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
+
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+ else if (png_ptr->chunk_name == png_sBIT)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
return;
}
- png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
+ png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
-#if defined(PNG_READ_sBIT_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
+#ifdef PNG_READ_cHRM_SUPPORTED
+ else if (png_ptr->chunk_name == png_cHRM)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
return;
}
- png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
+ png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
-#if defined(PNG_READ_cHRM_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
+#ifdef PNG_READ_sRGB_SUPPORTED
+ else if (chunk_name == png_sRGB)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
return;
}
- png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
+ png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
-#if defined(PNG_READ_sRGB_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
+#ifdef PNG_READ_iCCP_SUPPORTED
+ else if (png_ptr->chunk_name == png_iCCP)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
return;
}
- png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
+ png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+#endif
+#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_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
-#if defined(PNG_READ_tRNS_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
+#ifdef PNG_READ_tRNS_SUPPORTED
+ else if (chunk_name == png_tRNS)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
-#if defined(PNG_READ_bKGD_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
+#ifdef PNG_READ_bKGD_SUPPORTED
+ else if (chunk_name == png_bKGD)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
-#if defined(PNG_READ_hIST_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
+#ifdef PNG_READ_hIST_SUPPORTED
+ else if (chunk_name == png_hIST)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
-#if defined(PNG_READ_pHYs_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
+#ifdef PNG_READ_pHYs_SUPPORTED
+ else if (chunk_name == png_pHYs)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
-#if defined(PNG_READ_oFFs_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
+#ifdef PNG_READ_oFFs_SUPPORTED
+ else if (chunk_name == png_oFFs)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
-#if defined(PNG_READ_pCAL_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+ else if (chunk_name == png_pCAL)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
}
+
+#endif
+#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_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
#endif
-#if defined(PNG_READ_tIME_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
+#ifdef PNG_READ_tIME_SUPPORTED
+ else if (chunk_name == png_tIME)
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
}
+
+#endif
+#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_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
#endif
-#if defined(PNG_READ_tEXt_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
+#ifdef PNG_READ_zTXt_SUPPORTED
+ else if (chunk_name == png_zTXt)
{
- png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
-#if defined(PNG_READ_zTXt_SUPPORTED)
- else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
+#ifdef PNG_READ_iTXt_SUPPORTED
+ else if (chunk_name == png_iTXt)
{
- png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
}
+
#endif
else
{
- png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
+ PNG_HANDLE_CHUNK_AS_DEFAULT);
}
- png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER;
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
}
-void
-png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
+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
-png_push_crc_finish(png_structp png_ptr)
+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_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;
- if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
- save_size = (png_size_t)png_ptr->skip_length;
else
- save_size = png_ptr->save_buffer_size;
+ skip_length = (png_uint_32)save_size;
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
- png_ptr->skip_length -= 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_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;
- if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
- save_size = (png_size_t)png_ptr->skip_length;
else
- save_size = png_ptr->current_buffer_size;
+ skip_length = (png_uint_32)save_size;
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
- png_ptr->skip_length -= 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;
}
}
-void
+void PNGCBAPI
png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
{
png_bytep ptr;
+ if (png_ptr == NULL)
+ return;
+
ptr = buffer;
if (png_ptr->save_buffer_size)
{
if (length < png_ptr->save_buffer_size)
save_size = length;
+
else
save_size = png_ptr->save_buffer_size;
- png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
+ memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
length -= save_size;
ptr += save_size;
png_ptr->buffer_size -= save_size;
if (length < png_ptr->current_buffer_size)
save_size = length;
+
else
save_size = png_ptr->current_buffer_size;
- png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
+ memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
png_ptr->buffer_size -= save_size;
png_ptr->current_buffer_size -= save_size;
png_ptr->current_buffer_ptr += save_size;
}
}
-void
-png_push_save_buffer(png_structp png_ptr)
+void /* PRIVATE */
+png_push_save_buffer(png_structrp png_ptr)
{
if (png_ptr->save_buffer_size)
{
if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
{
- png_size_t i;
+ png_size_t i, istop;
png_bytep sp;
png_bytep dp;
+ istop = png_ptr->save_buffer_size;
for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
- i < png_ptr->save_buffer_size;
- i++, sp++, dp++)
+ i < istop; i++, sp++, dp++)
{
*dp = *sp;
}
}
}
if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
- png_ptr->save_buffer_max)
+ png_ptr->save_buffer_max)
{
png_size_t new_max;
png_bytep old_buffer;
+ if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
+ (png_ptr->current_buffer_size + 256))
+ {
+ png_error(png_ptr, "Potential overflow of save_buffer");
+ }
+
new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
old_buffer = png_ptr->save_buffer;
- png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)new_max);
- png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+ png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
+ (png_size_t)new_max);
+
+ if (png_ptr->save_buffer == NULL)
+ {
+ png_free(png_ptr, old_buffer);
+ png_error(png_ptr, "Insufficient memory for save_buffer");
+ }
+
+ memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
png_free(png_ptr, old_buffer);
png_ptr->save_buffer_max = new_max;
}
if (png_ptr->current_buffer_size)
{
- png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
+ memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
png_ptr->save_buffer_size += png_ptr->current_buffer_size;
png_ptr->current_buffer_size = 0;
png_ptr->buffer_size = 0;
}
-void
-png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
+void /* PRIVATE */
+png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer,
png_size_t buffer_length)
{
png_ptr->current_buffer = buffer;
png_ptr->current_buffer_ptr = png_ptr->current_buffer;
}
-void
-png_push_read_IDAT(png_structp png_ptr)
+void /* PRIVATE */
+png_push_read_IDAT(png_structrp png_ptr)
{
- if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER))
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
{
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);
}
png_push_fill_buffer(png_ptr, chunk_length, 4);
- png_ptr->push_length = png_get_uint_32(chunk_length);
-
+ png_ptr->push_length = 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->flags |= PNG_FLAG_HAVE_CHUNK_HEADER;
+ png_crc_read(png_ptr, chunk_tag, 4);
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
- if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ if (png_ptr->chunk_name != png_IDAT)
{
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
- if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+
+ if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
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)
{
- png_size_t save_size;
+ png_size_t save_size = png_ptr->save_buffer_size;
+ png_uint_32 idat_size = png_ptr->idat_size;
+
+ /* We want the smaller of 'idat_size' and 'current_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 (idat_size < save_size)
+ save_size = (png_size_t)idat_size;
- if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
- {
- save_size = (png_size_t)png_ptr->idat_size;
- /* check for overflow */
- if((png_uint_32)save_size != png_ptr->idat_size)
- png_error(png_ptr, "save_size overflowed in pngpread");
- }
else
- save_size = png_ptr->save_buffer_size;
+ idat_size = (png_uint_32)save_size;
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
- png_ptr->idat_size -= save_size;
+ png_ptr->idat_size -= idat_size;
png_ptr->buffer_size -= save_size;
png_ptr->save_buffer_size -= save_size;
png_ptr->save_buffer_ptr += save_size;
}
+
if (png_ptr->idat_size && png_ptr->current_buffer_size)
{
- png_size_t save_size;
+ png_size_t save_size = png_ptr->current_buffer_size;
+ png_uint_32 idat_size = png_ptr->idat_size;
+
+ /* We want the smaller of 'idat_size' and 'current_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.
+ */
+ if (idat_size < save_size)
+ save_size = (png_size_t)idat_size;
- if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
- {
- save_size = (png_size_t)png_ptr->idat_size;
- /* check for overflow */
- if((png_uint_32)save_size != png_ptr->idat_size)
- png_error(png_ptr, "save_size overflowed in pngpread");
- }
else
- save_size = png_ptr->current_buffer_size;
+ idat_size = (png_uint_32)save_size;
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
- png_ptr->idat_size -= save_size;
+ png_ptr->idat_size -= idat_size;
png_ptr->buffer_size -= save_size;
png_ptr->current_buffer_size -= save_size;
png_ptr->current_buffer_ptr += save_size;
}
png_crc_finish(png_ptr, 0);
- png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER;
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->zowner = 0;
}
}
-void
-png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
+void /* PRIVATE */
+png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
png_size_t buffer_length)
{
- int ret;
-
- if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
- png_error(png_ptr, "Extra compression data");
+ /* The caller checks for a non-zero buffer length. */
+ if (!(buffer_length > 0) || buffer == NULL)
+ png_error(png_ptr, "No IDAT data (internal error)");
+ /* This routine must process all the data it has been given
+ * before returning, calling the row callback as required to
+ * handle the uncompressed results.
+ */
png_ptr->zstream.next_in = buffer;
+ /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
png_ptr->zstream.avail_in = (uInt)buffer_length;
- for(;;)
+
+ /* Keep going until the decompressed data is all processed
+ * or the stream marked as finished.
+ */
+ while (png_ptr->zstream.avail_in > 0 &&
+ !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
{
- ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
- if (ret == Z_STREAM_END)
+ int ret;
+
+ /* We have data for zlib, but we must check that zlib
+ * has someplace to put the results. It doesn't matter
+ * if we don't expect any results -- it may be the input
+ * data is just the LZ end code.
+ */
+ if (!(png_ptr->zstream.avail_out > 0))
{
- if (png_ptr->zstream.avail_in)
- png_error(png_ptr, "Extra compressed data");
- if (!(png_ptr->zstream.avail_out))
- {
- png_push_process_row(png_ptr);
- }
+ /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
+ png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1);
- png_ptr->mode |= PNG_AFTER_IDAT;
- png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
- break;
+ png_ptr->zstream.next_out = png_ptr->row_buf;
}
- else if (ret == Z_BUF_ERROR)
- break;
- else if (ret != Z_OK)
- png_error(png_ptr, "Decompression Error");
- if (!(png_ptr->zstream.avail_out))
+
+ /* Using Z_SYNC_FLUSH here means that an unterminated
+ * LZ stream (a stream with a missing end code) can still
+ * be handled, otherwise (Z_NO_FLUSH) a future zlib
+ * implementation might defer output and therefore
+ * 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);
+
+ /* Check for any failure before proceeding. */
+ if (ret != Z_OK && ret != Z_STREAM_END)
{
- png_push_process_row(png_ptr);
- png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
- png_ptr->zstream.next_out = png_ptr->row_buf;
+ /* Terminate the decompression. */
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ png_ptr->zowner = 0;
+
+ /* This may be a truncated stream (missing or
+ * damaged end code). Treat that as a warning.
+ */
+ if (png_ptr->row_number >= png_ptr->num_rows ||
+ png_ptr->pass > 6)
+ png_warning(png_ptr, "Truncated compressed data in IDAT");
+
+ else
+ png_error(png_ptr, "Decompression error in IDAT");
+
+ /* Skip the check on unprocessed input */
+ return;
}
- else
- break;
+
+ /* Did inflate output any data? */
+ if (png_ptr->zstream.next_out != png_ptr->row_buf)
+ {
+ /* Is this unexpected data after the last row?
+ * If it is, artificially terminate the LZ output
+ * here.
+ */
+ if (png_ptr->row_number >= png_ptr->num_rows ||
+ png_ptr->pass > 6)
+ {
+ /* Extra data. */
+ png_warning(png_ptr, "Extra compressed data in IDAT");
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ png_ptr->zowner = 0;
+
+ /* Do no more processing; skip the unprocessed
+ * input check below.
+ */
+ return;
+ }
+
+ /* Do we have a complete row? */
+ if (png_ptr->zstream.avail_out == 0)
+ png_push_process_row(png_ptr);
+ }
+
+ /* And check for the end of the stream. */
+ if (ret == Z_STREAM_END)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
}
+
+ /* All the data should have been processed, if anything
+ * is left at this point we have bytes of IDAT data
+ * after the zlib end code.
+ */
+ if (png_ptr->zstream.avail_in > 0)
+ png_warning(png_ptr, "Extra compression data in IDAT");
}
-void
-png_push_process_row(png_structp png_ptr)
+void /* PRIVATE */
+png_push_process_row(png_structrp png_ptr)
{
- png_ptr->row_info.color_type = png_ptr->color_type;
- png_ptr->row_info.width = png_ptr->iwidth;
- png_ptr->row_info.channels = png_ptr->channels;
- png_ptr->row_info.bit_depth = png_ptr->bit_depth;
- png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
-
- png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
- (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
-
- png_read_filter_row(png_ptr, &(png_ptr->row_info),
- png_ptr->row_buf + 1, png_ptr->prev_row + 1,
- (int)(png_ptr->row_buf[0]));
-
- png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
- png_ptr->rowbytes + 1);
+ /* 1.5.6: row_info moved out of png_struct to a local here. */
+ png_row_info row_info;
+
+ row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+ row_info.color_type = png_ptr->color_type;
+ row_info.bit_depth = png_ptr->bit_depth;
+ row_info.channels = png_ptr->channels;
+ row_info.pixel_depth = png_ptr->pixel_depth;
+ row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+ if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+ {
+ if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+ png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+ png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+ else
+ png_error(png_ptr, "bad adaptive filter value");
+ }
+ /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+ * 1.5.6, while the buffer really is this big in current versions of libpng
+ * it may not be in the future, so this was changed just to copy the
+ * interlaced row count:
+ */
+ memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
if (png_ptr->transformations)
- png_do_read_transformations(png_ptr);
+ png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+ /* The transformed pixel depth should match the depth now in row_info. */
+ if (png_ptr->transformed_pixel_depth == 0)
+ {
+ png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+ if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+ png_error(png_ptr, "progressive row overflow");
+ }
+
+ else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+ png_error(png_ptr, "internal progressive row size calculation error");
-#if defined(PNG_READ_INTERLACING_SUPPORTED)
- /* blow up interlaced rows to full size */
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Blow up interlaced rows to full size */
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
{
if (png_ptr->pass < 6)
- png_do_read_interlace(&(png_ptr->row_info),
- png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
+ png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+ png_ptr->transformations);
- switch (png_ptr->pass)
- {
+ switch (png_ptr->pass)
+ {
case 0:
{
int i;
for (i = 0; i < 8 && png_ptr->pass == 0; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
- png_read_push_finish_row(png_ptr);
+ png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
+ }
+
+ if (png_ptr->pass == 2) /* Pass 1 might be empty */
+ {
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ if (png_ptr->pass == 4 && png_ptr->height <= 4)
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ if (png_ptr->pass == 6 && png_ptr->height <= 4)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
}
+
break;
}
+
case 1:
{
int i;
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
- if (png_ptr->pass == 2)
+
+ if (png_ptr->pass == 2) /* Skip top 4 generated rows */
{
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
{
png_read_push_finish_row(png_ptr);
}
}
+
break;
}
+
case 2:
{
int i;
+
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
+
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
{
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
+
+ if (png_ptr->pass == 4) /* Pass 3 might be empty */
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
break;
}
+
case 3:
{
int i;
+
for (i = 0; i < 4 && png_ptr->pass == 3; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
- if (png_ptr->pass == 4)
+
+ if (png_ptr->pass == 4) /* Skip top two generated rows */
{
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
{
png_read_push_finish_row(png_ptr);
}
}
+
break;
}
+
case 4:
{
int i;
+
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
+
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
{
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
+
+ if (png_ptr->pass == 6) /* Pass 5 might be empty */
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
break;
}
+
case 5:
{
int i;
+
for (i = 0; i < 2 && png_ptr->pass == 5; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
- if (png_ptr->pass == 6)
+
+ if (png_ptr->pass == 6) /* Skip top generated row */
{
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
+
break;
}
+
+ default:
case 6:
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
+
if (png_ptr->pass != 6)
break;
+
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
}
}
-void
-png_read_push_finish_row(png_structp png_ptr)
-{
- png_ptr->row_number++;
- if (png_ptr->row_number < png_ptr->num_rows)
- return;
-
- if (png_ptr->interlaced)
- {
- png_ptr->row_number = 0;
- png_memset_check(png_ptr, png_ptr->prev_row, 0,
- png_ptr->rowbytes + 1);
- do
- {
- png_ptr->pass++;
- if (png_ptr->pass >= 7)
- break;
- png_ptr->iwidth = (png_ptr->width +
- png_pass_inc[png_ptr->pass] - 1 -
- png_pass_start[png_ptr->pass]) /
- png_pass_inc[png_ptr->pass];
-
- png_ptr->irowbytes = ((png_ptr->iwidth *
- png_ptr->pixel_depth + 7) >> 3) + 1;
-
- if (!(png_ptr->transformations & PNG_INTERLACE))
- {
- png_ptr->num_rows = (png_ptr->height +
- png_pass_yinc[png_ptr->pass] - 1 -
- png_pass_ystart[png_ptr->pass]) /
- png_pass_yinc[png_ptr->pass];
- if (!(png_ptr->num_rows))
- continue;
- }
- if (png_ptr->transformations & PNG_INTERLACE)
- break;
- } while (png_ptr->iwidth == 0);
- }
-}
-
-#if defined(PNG_READ_tEXt_SUPPORTED)
-void
-png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
-{
- if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND)
- {
- png_error(png_ptr, "Out of place tEXt");
- /* to quiet some compiler warnings */
- if(info_ptr == NULL) return;
- }
-
-#ifdef PNG_MAX_MALLOC_64K
- png_ptr->skip_length = 0; /* This may not be necessary */
-
- if (length > (png_uint_32)65535L) /* Can't hold the 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_uint_32)(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
-png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
+void /* PRIVATE */
+png_read_push_finish_row(png_structrp png_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;
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
- if (png_ptr->buffer_size < 4)
- {
- png_push_save_buffer(png_ptr);
- return;
- }
-
- png_push_crc_finish(png_ptr);
-
-#if defined(PNG_MAX_MALLOC_64K)
- if (png_ptr->skip_length)
- return;
-#endif
-
- key = png_ptr->current_text;
- png_ptr->current_text = 0;
-
- for (text = key; *text; text++)
- /* empty loop */ ;
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
- if (text != key + png_ptr->current_text_size)
- text++;
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
- text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
- text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
- text_ptr->key = key;
- text_ptr->text = text;
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
- png_set_text(png_ptr, info_ptr, text_ptr, 1);
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
- png_free(png_ptr, text_ptr);
- }
-}
+ /* Height of interlace block. This is not currently used - if you need
+ * it, uncomment it here and in png.h
+ static PNG_CONST png_byte png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+ */
#endif
-#if defined(PNG_READ_zTXt_SUPPORTED)
-void
-png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
-{
- if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND)
- {
- png_error(png_ptr, "Out of place zTXt");
- /* to quiet some compiler warnings */
- if(info_ptr == NULL) return;
- }
-
-#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);
+ png_ptr->row_number++;
+ if (png_ptr->row_number < png_ptr->num_rows)
return;
- }
-#endif
-
- png_ptr->current_text = (png_charp)png_malloc(png_ptr,
- (png_uint_32)(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
-png_push_read_zTXt(png_structp png_ptr, png_infop 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))
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced)
{
- 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;
- png_ptr->current_text = 0;
-
- for (text = key; *text; text++)
- /* empty loop */ ;
-
- /* zTXt can't have zero text */
- if (text == key + png_ptr->current_text_size)
- {
- png_free(png_ptr, key);
- return;
- }
-
- text++;
+ png_ptr->row_number = 0;
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
- if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */
+ do
{
- 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;
+ png_ptr->pass++;
+ if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
+ (png_ptr->pass == 3 && png_ptr->width < 3) ||
+ (png_ptr->pass == 5 && png_ptr->width < 2))
+ png_ptr->pass++;
- 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_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_uint_32)(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_uint_32)(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 (png_ptr->pass > 7)
+ png_ptr->pass--;
- if (ret == Z_STREAM_END)
+ if (png_ptr->pass >= 7)
break;
- }
-
- inflateReset(&png_ptr->zstream);
- png_ptr->zstream.avail_in = 0;
-
- if (ret != Z_STREAM_END)
- {
- png_free(png_ptr, key);
- png_free(png_ptr, text);
- return;
- }
- png_free(png_ptr, key);
- key = text;
- text += key_size;
-
- text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
- text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
- text_ptr->key = key;
- text_ptr->text = text;
-
- png_set_text(png_ptr, info_ptr, text_ptr, 1);
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
- png_free(png_ptr, text_ptr);
- }
-}
-#endif
+ if (png_ptr->transformations & PNG_INTERLACE)
+ break;
-/* This function is called when we haven't found a handler for this
- * chunk. In the future we will have code here which can handle
- * user-defined callback functions for unknown chunks before they are
- * ignored or cause an error. 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
-png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
-{
- png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
- if (!(png_ptr->chunk_name[0] & 0x20))
- {
- png_chunk_error(png_ptr, "unknown critical chunk");
- /* to quiet some compiler warnings */
- if(info_ptr == NULL) return;
+ } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
}
-
- png_push_crc_skip(png_ptr, length);
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
}
-void
-png_push_have_info(png_structp png_ptr, png_infop info_ptr)
+void /* PRIVATE */
+png_push_have_info(png_structrp png_ptr, png_inforp info_ptr)
{
if (png_ptr->info_fn != NULL)
(*(png_ptr->info_fn))(png_ptr, info_ptr);
}
-void
-png_push_have_end(png_structp png_ptr, png_infop info_ptr)
+void /* PRIVATE */
+png_push_have_end(png_structrp png_ptr, png_inforp info_ptr)
{
if (png_ptr->end_fn != NULL)
(*(png_ptr->end_fn))(png_ptr, info_ptr);
}
-void
-png_push_have_row(png_structp png_ptr, png_bytep row)
+void /* PRIVATE */
+png_push_have_row(png_structrp png_ptr, png_bytep row)
{
if (png_ptr->row_fn != NULL)
(*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
(int)png_ptr->pass);
}
-void
-png_progressive_combine_row (png_structp png_ptr,
- png_bytep old_row, png_bytep new_row)
+#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 (png_ptr == NULL)
+ return;
+
+ /* new_row is a flag here - if it is NULL then the app callback was called
+ * from an empty row (see the calls to png_struct::row_fn below), otherwise
+ * it must be png_ptr->row_buf+1
+ */
if (new_row != NULL)
- png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
+ png_combine_row(png_ptr, old_row, 1/*display*/);
}
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
-void
-png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
- png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
- png_progressive_end_ptr end_fn)
+void PNGAPI
+png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr,
+ png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+ png_progressive_end_ptr end_fn)
{
+ if (png_ptr == NULL)
+ return;
+
png_ptr->info_fn = info_fn;
png_ptr->row_fn = row_fn;
png_ptr->end_fn = end_fn;
png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
}
-png_voidp
-png_get_progressive_ptr(png_structp png_ptr)
+png_voidp PNGAPI
+png_get_progressive_ptr(png_const_structrp png_ptr)
{
+ if (png_ptr == NULL)
+ return (NULL);
+
return png_ptr->io_ptr;
}
-
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-
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