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[libpng16] Made read 'inflate' handling like write 'deflate' handling. The

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read code now claims and releases png_ptr->zstream, like the write code.
The bug whereby the progressive reader failed to release the zstream
is now fixed, all initialization is delayed, and the code checks for
changed parameters on deflate rather than always calling
deflatedEnd/deflateInit.
This commit is contained in:
John Bowler
2012-03-05 20:57:40 -06:00
committed by Glenn Randers-Pehrson
parent e2ae0f2f2b
commit 42a2b556e9
10 changed files with 360 additions and 340 deletions
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77
pngread.c
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@@ -48,61 +48,14 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
if (png_ptr != NULL)
{
int ok = 0;
/* TODO: why does this happen here on read, but in png_write_IHDR on
* write? If it happened there then there would be no error handling case
* here and png_ptr could be a png_structrp.
/* TODO: delay this, it can be done in png_init_io (if the app doesn't
* do it itself) avoiding setting the default function if it is not
* required.
*/
png_ptr->zstream.zalloc = png_zalloc;
png_ptr->zstream.zfree = png_zfree;
png_ptr->zstream.opaque = png_ptr;
switch (inflateInit(&png_ptr->zstream))
{
case Z_OK:
ok = 1;
break;
case Z_MEM_ERROR:
png_warning(png_ptr, "zlib memory error");
break;
case Z_STREAM_ERROR:
png_warning(png_ptr, "zlib stream error");
break;
case Z_VERSION_ERROR:
png_warning(png_ptr, "zlib version error");
break;
default:
png_warning(png_ptr, "Unknown zlib error");
break;
}
if (ok)
{
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = png_ptr->zbuf_size;
/* TODO: delay this, it can be done in png_init_io (if the app doesn't
* do it itself) avoiding setting the default function if it is not
* required.
*/
png_set_read_fn(png_ptr, NULL, NULL);
return png_ptr;
}
/* Else something went wrong in the zlib initialization above; it would
* much simplify this code if the creation of the zlib stuff was to be
* delayed until it is needed.
*/
png_destroy_read_struct(&png_ptr, NULL, NULL);
png_set_read_fn(png_ptr, NULL, NULL);
}
return NULL;
return png_ptr;
}
@@ -471,15 +424,17 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
png_error(png_ptr, "Invalid attempt to read row data");
png_ptr->zstream.next_out = png_ptr->row_buf;
png_ptr->zstream.avail_out =
(uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
/* TODO: WARNING: BAD NEWS ALERT: this fails, terminally, if the row width is
* bigger than a uInt.
*/
png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
png_ptr->iwidth) + 1);
do
{
if (!(png_ptr->zstream.avail_in))
{
while (!png_ptr->idat_size)
while (png_ptr->idat_size == 0)
{
png_crc_finish(png_ptr, 0);
@@ -487,7 +442,7 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
if (png_ptr->chunk_name != png_IDAT)
png_error(png_ptr, "Not enough image data");
}
png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
png_ptr->zstream.avail_in = png_ptr->zbuf_size;
png_ptr->zstream.next_in = png_ptr->zbuf;
if (png_ptr->zbuf_size > png_ptr->idat_size)
png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
@@ -495,7 +450,11 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
png_ptr->idat_size -= png_ptr->zstream.avail_in;
}
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
/* Use NO_FLUSH, not SYNC_FLUSH, here because we keep reading data until
* we have a row to process (so leave it to zlib to decide when to flush
* the output.)
*/
ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
if (ret == Z_STREAM_END)
{
@@ -503,7 +462,9 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
png_ptr->idat_size)
png_benign_error(png_ptr, "Extra compressed data");
png_ptr->mode |= PNG_AFTER_IDAT;
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
/* Release the stream */
png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
png_ptr->flags &= ~PNG_FLAG_ZSTREAM_IN_USE;
break;
}