diff options
| author | Lei Zhang <thestig@chromium.org> | 2016-01-15 12:20:27 -0800 |
|---|---|---|
| committer | Lei Zhang <thestig@chromium.org> | 2016-01-15 12:20:27 -0800 |
| commit | fa92864d257f57e5afdc0a36eafad8f2575c528a (patch) | |
| tree | d792e53ea13f87d1fa2995127c864621b7701146 /third_party/lpng_v163/pngrutil.c | |
| parent | 45f2a47df2d6505c351ee0586969bf142c93bf6b (diff) | |
| download | pdfium-fa92864d257f57e5afdc0a36eafad8f2575c528a.tar.xz | |
XFA: Upgrade libpng to 1.6.20.
R=tsepez@chromium.org
Review URL: https://codereview.chromium.org/1591483003 .
Diffstat (limited to 'third_party/lpng_v163/pngrutil.c')
| -rw-r--r-- | third_party/lpng_v163/pngrutil.c | 4471 |
1 files changed, 0 insertions, 4471 deletions
diff --git a/third_party/lpng_v163/pngrutil.c b/third_party/lpng_v163/pngrutil.c deleted file mode 100644 index 970ec4d4d9..0000000000 --- a/third_party/lpng_v163/pngrutil.c +++ /dev/null @@ -1,4471 +0,0 @@ -/* pngrutil.c - utilities to read a PNG file
- *
- * Last changed in libpng 1.6.3 [July 18, 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
- *
- * This file contains routines that are only called from within
- * libpng itself during the course of reading an image.
- */
-
-#include "pngpriv.h"
-
-#ifdef PNG_READ_SUPPORTED
-
-png_uint_32 PNGAPI
-png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf)
-{
- png_uint_32 uval = png_get_uint_32(buf);
-
- if (uval > PNG_UINT_31_MAX)
- png_error(png_ptr, "PNG unsigned integer out of range");
-
- return (uval);
-}
-
-#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED)
-/* The following is a variation on the above for use with the fixed
- * point values used for gAMA and cHRM. Instead of png_error it
- * issues a warning and returns (-1) - an invalid value because both
- * gAMA and cHRM use *unsigned* integers for fixed point values.
- */
-#define PNG_FIXED_ERROR (-1)
-
-static png_fixed_point /* PRIVATE */
-png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf)
-{
- png_uint_32 uval = png_get_uint_32(buf);
-
- if (uval <= PNG_UINT_31_MAX)
- return (png_fixed_point)uval; /* known to be in range */
-
- /* The caller can turn off the warning by passing NULL. */
- if (png_ptr != NULL)
- png_warning(png_ptr, "PNG fixed point integer out of range");
-
- return PNG_FIXED_ERROR;
-}
-#endif
-
-#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
-/* NOTE: the read macros will obscure these definitions, so that if
- * PNG_USE_READ_MACROS is set the library will not use them internally,
- * but the APIs will still be available externally.
- *
- * The parentheses around "PNGAPI function_name" in the following three
- * functions are necessary because they allow the macros to co-exist with
- * these (unused but exported) functions.
- */
-
-/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
-png_uint_32 (PNGAPI
-png_get_uint_32)(png_const_bytep buf)
-{
- png_uint_32 uval =
- ((png_uint_32)(*(buf )) << 24) +
- ((png_uint_32)(*(buf + 1)) << 16) +
- ((png_uint_32)(*(buf + 2)) << 8) +
- ((png_uint_32)(*(buf + 3)) ) ;
-
- return uval;
-}
-
-/* Grab a signed 32-bit integer from a buffer in big-endian format. The
- * data is stored in the PNG file in two's complement format and there
- * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
- * the following code does a two's complement to native conversion.
- */
-png_int_32 (PNGAPI
-png_get_int_32)(png_const_bytep buf)
-{
- png_uint_32 uval = png_get_uint_32(buf);
- if ((uval & 0x80000000) == 0) /* non-negative */
- return uval;
-
- uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
- return -(png_int_32)uval;
-}
-
-/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
-png_uint_16 (PNGAPI
-png_get_uint_16)(png_const_bytep buf)
-{
- /* ANSI-C requires an int value to accomodate at least 16 bits so this
- * works and allows the compiler not to worry about possible narrowing
- * on 32 bit systems. (Pre-ANSI systems did not make integers smaller
- * than 16 bits either.)
- */
- unsigned int val =
- ((unsigned int)(*buf) << 8) +
- ((unsigned int)(*(buf + 1)));
-
- return (png_uint_16)val;
-}
-
-#endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */
-
-/* Read and check the PNG file signature */
-void /* PRIVATE */
-png_read_sig(png_structrp png_ptr, png_inforp 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.
- */
-png_uint_32 /* PRIVATE */
-png_read_chunk_header(png_structrp png_ptr)
-{
- png_byte buf[8];
- png_uint_32 length;
-
-#ifdef PNG_IO_STATE_SUPPORTED
- png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
-#endif
-
- /* 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. */
- png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
-
- png_debug2(0, "Reading %lx chunk, length = %lu",
- (unsigned long)png_ptr->chunk_name, (unsigned long)length);
-
- /* Reset the crc and run it over the chunk name. */
- png_reset_crc(png_ptr);
- png_calculate_crc(png_ptr, buf + 4, 4);
-
- /* Check to see if chunk name is valid. */
- png_check_chunk_name(png_ptr, png_ptr->chunk_name);
-
-#ifdef PNG_IO_STATE_SUPPORTED
- png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
-#endif
-
- return length;
-}
-
-/* Read data, and (optionally) run it through the CRC. */
-void /* PRIVATE */
-png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length)
-{
- if (png_ptr == NULL)
- return;
-
- png_read_data(png_ptr, buf, length);
- png_calculate_crc(png_ptr, buf, length);
-}
-
-/* Optionally skip data and then check the CRC. Depending on whether we
- * are reading an ancillary or critical chunk, and how the program has set
- * things up, we may calculate the CRC on the data and print a message.
- * Returns '1' if there was a CRC error, '0' otherwise.
- */
-int /* PRIVATE */
-png_crc_finish(png_structrp png_ptr, png_uint_32 skip)
-{
- /* The size of the local buffer for inflate is a good guess as to a
- * reasonable size to use for buffering reads from the application.
- */
- while (skip > 0)
- {
- png_uint_32 len;
- png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
-
- len = (sizeof tmpbuf);
- if (len > skip)
- len = skip;
- skip -= len;
-
- png_crc_read(png_ptr, tmpbuf, len);
- }
-
- if (png_crc_error(png_ptr))
- {
- if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) ?
- !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) :
- (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))
- {
- png_chunk_warning(png_ptr, "CRC error");
- }
-
- else
- {
- png_chunk_benign_error(png_ptr, "CRC error");
- return (0);
- }
-
- return (1);
- }
-
- return (0);
-}
-
-/* Compare the CRC stored in the PNG file with that calculated by libpng from
- * the data it has read thus far.
- */
-int /* PRIVATE */
-png_crc_error(png_structrp png_ptr)
-{
- png_byte crc_bytes[4];
- png_uint_32 crc;
- int need_crc = 1;
-
- if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))
- {
- if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
- (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
- need_crc = 0;
- }
-
- else /* critical */
- {
- if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
- need_crc = 0;
- }
-
-#ifdef PNG_IO_STATE_SUPPORTED
- 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)
- {
- crc = png_get_uint_32(crc_bytes);
- return ((int)(crc != png_ptr->crc));
- }
-
- else
- return (0);
-}
-
-/* Manage the read buffer; this simply reallocates the buffer if it is not small
- * enough (or if it is not allocated). The routine returns a pointer to the
- * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
- * it will call png_error (via png_malloc) on failure. (warn == 2 means
- * 'silent').
- */
-static png_bytep
-png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
-{
- png_bytep buffer = png_ptr->read_buffer;
-
- if (buffer != NULL && new_size > png_ptr->read_buffer_size)
- {
- png_ptr->read_buffer = NULL;
- png_ptr->read_buffer = NULL;
- png_ptr->read_buffer_size = 0;
- png_free(png_ptr, buffer);
- buffer = NULL;
- }
-
- if (buffer == NULL)
- {
- buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size));
-
- if (buffer != NULL)
- {
- png_ptr->read_buffer = buffer;
- png_ptr->read_buffer_size = new_size;
- }
-
- else if (warn < 2) /* else silent */
- {
-#ifdef PNG_WARNINGS_SUPPORTED
- if (warn)
- png_chunk_warning(png_ptr, "insufficient memory to read chunk");
- else
-#endif
- {
-#ifdef PNG_ERROR_TEXT_SUPPORTED
- png_chunk_error(png_ptr, "insufficient memory to read chunk");
-#endif
- }
- }
- }
-
- return buffer;
-}
-
-/* png_inflate_claim: claim the zstream for some nefarious purpose that involves
- * decompression. Returns Z_OK on success, else a zlib error code. It checks
- * the owner but, in final release builds, just issues a warning if some other
- * chunk apparently owns the stream. Prior to release it does a png_error.
- */
-static int
-png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
-{
- if (png_ptr->zowner != 0)
- {
- char msg[64];
-
- PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner);
- /* So the message that results is "<chunk> using zstream"; this is an
- * internal error, but is very useful for debugging. i18n requirements
- * are minimal.
- */
- (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
-# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
- png_chunk_warning(png_ptr, msg);
- png_ptr->zowner = 0;
-# else
- png_chunk_error(png_ptr, msg);
-# endif
- }
-
- /* Implementation note: unlike 'png_deflate_claim' this internal function
- * does not take the size of the data as an argument. Some efficiency could
- * be gained by using this when it is known *if* the zlib stream itself does
- * not record the number; however, this is an illusion: the original writer
- * of the PNG may have selected a lower window size, and we really must
- * follow that because, for systems with with limited capabilities, we
- * would otherwise reject the application's attempts to use a smaller window
- * size (zlib doesn't have an interface to say "this or lower"!).
- *
- * inflateReset2 was added to zlib 1.2.4; before this the window could not be
- * reset, therefore it is necessary to always allocate the maximum window
- * size with earlier zlibs just in case later compressed chunks need it.
- */
- {
- int ret; /* zlib return code */
-# if PNG_ZLIB_VERNUM >= 0x1240
-
-# if defined(PNG_SET_OPTION_SUPPORTED) && \
- defined(PNG_MAXIMUM_INFLATE_WINDOW)
- int window_bits;
-
- if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) ==
- PNG_OPTION_ON)
- window_bits = 15;
-
- else
- window_bits = 0;
-# else
-# define window_bits 0
-# endif
-# endif
-
- /* Set this for safety, just in case the previous owner left pointers to
- * memory allocations.
- */
- png_ptr->zstream.next_in = NULL;
- png_ptr->zstream.avail_in = 0;
- png_ptr->zstream.next_out = NULL;
- png_ptr->zstream.avail_out = 0;
-
- if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
- {
-# if PNG_ZLIB_VERNUM < 0x1240
- ret = inflateReset(&png_ptr->zstream);
-# else
- ret = inflateReset2(&png_ptr->zstream, window_bits);
-# endif
- }
-
- else
- {
-# if PNG_ZLIB_VERNUM < 0x1240
- ret = inflateInit(&png_ptr->zstream);
-# else
- ret = inflateInit2(&png_ptr->zstream, window_bits);
-# endif
-
- if (ret == Z_OK)
- png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
- }
-
- if (ret == Z_OK)
- png_ptr->zowner = owner;
-
- else
- png_zstream_error(png_ptr, ret);
-
- return ret;
- }
-
-# ifdef window_bits
-# undef window_bits
-# endif
-}
-
-#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
-/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to
- * allow the caller to do multiple calls if required. If the 'finish' flag is
- * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must
- * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and
- * Z_OK or Z_STREAM_END will be returned on success.
- *
- * The input and output sizes are updated to the actual amounts of data consumed
- * or written, not the amount available (as in a z_stream). The data pointers
- * are not changed, so the next input is (data+input_size) and the next
- * available output is (output+output_size).
- */
-static int
-png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
- /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr,
- /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr)
-{
- if (png_ptr->zowner == owner) /* Else not claimed */
- {
- int ret;
- png_alloc_size_t avail_out = *output_size_ptr;
- png_uint_32 avail_in = *input_size_ptr;
-
- /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it
- * can't even necessarily handle 65536 bytes) because the type uInt is
- * "16 bits or more". Consequently it is necessary to chunk the input to
- * zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the
- * maximum value that can be stored in a uInt.) It is possible to set
- * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have
- * a performance advantage, because it reduces the amount of data accessed
- * at each step and that may give the OS more time to page it in.
- */
- png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
- /* avail_in and avail_out are set below from 'size' */
- png_ptr->zstream.avail_in = 0;
- png_ptr->zstream.avail_out = 0;
-
- /* Read directly into the output if it is available (this is set to
- * a local buffer below if output is NULL).
- */
- if (output != NULL)
- png_ptr->zstream.next_out = output;
-
- do
- {
- uInt avail;
- Byte local_buffer[PNG_INFLATE_BUF_SIZE];
-
- /* zlib INPUT BUFFER */
- /* The setting of 'avail_in' used to be outside the loop; by setting it
- * inside it is possible to chunk the input to zlib and simply rely on
- * zlib to advance the 'next_in' pointer. This allows arbitrary
- * amounts of data to be passed through zlib at the unavoidable cost of
- * requiring a window save (memcpy of up to 32768 output bytes)
- * every ZLIB_IO_MAX input bytes.
- */
- avail_in += png_ptr->zstream.avail_in; /* not consumed last time */
-
- avail = ZLIB_IO_MAX;
-
- if (avail_in < avail)
- avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */
-
- avail_in -= avail;
- png_ptr->zstream.avail_in = avail;
-
- /* zlib OUTPUT BUFFER */
- avail_out += png_ptr->zstream.avail_out; /* not written last time */
-
- avail = ZLIB_IO_MAX; /* maximum zlib can process */
-
- if (output == NULL)
- {
- /* Reset the output buffer each time round if output is NULL and
- * make available the full buffer, up to 'remaining_space'
- */
- png_ptr->zstream.next_out = local_buffer;
- if ((sizeof local_buffer) < avail)
- avail = (sizeof local_buffer);
- }
-
- if (avail_out < avail)
- avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */
-
- png_ptr->zstream.avail_out = avail;
- avail_out -= avail;
-
- /* zlib inflate call */
- /* In fact 'avail_out' may be 0 at this point, that happens at the end
- * of the read when the final LZ end code was not passed at the end of
- * the previous chunk of input data. Tell zlib if we have reached the
- * end of the output buffer.
- */
- ret = inflate(&png_ptr->zstream, avail_out > 0 ? Z_NO_FLUSH :
- (finish ? Z_FINISH : Z_SYNC_FLUSH));
- } while (ret == Z_OK);
-
- /* For safety kill the local buffer pointer now */
- if (output == NULL)
- png_ptr->zstream.next_out = NULL;
-
- /* Claw back the 'size' and 'remaining_space' byte counts. */
- avail_in += png_ptr->zstream.avail_in;
- avail_out += png_ptr->zstream.avail_out;
-
- /* Update the input and output sizes; the updated values are the amount
- * consumed or written, effectively the inverse of what zlib uses.
- */
- if (avail_out > 0)
- *output_size_ptr -= avail_out;
-
- if (avail_in > 0)
- *input_size_ptr -= avail_in;
-
- /* Ensure png_ptr->zstream.msg is set (even in the success case!) */
- png_zstream_error(png_ptr, ret);
- return ret;
- }
-
- else
- {
- /* This is a bad internal error. The recovery assigns to the zstream msg
- * pointer, which is not owned by the caller, but this is safe; it's only
- * used on errors!
- */
- png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
- return Z_STREAM_ERROR;
- }
-}
-
-/*
- * Decompress trailing data in a chunk. The assumption is that read_buffer
- * points at an allocated area holding the contents of a chunk with a
- * trailing compressed part. What we get back is an allocated area
- * holding the original prefix part and an uncompressed version of the
- * trailing part (the malloc area passed in is freed).
- */
-static int
-png_decompress_chunk(png_structrp png_ptr,
- png_uint_32 chunklength, png_uint_32 prefix_size,
- png_alloc_size_t *newlength /* must be initialized to the maximum! */,
- int terminate /*add a '\0' to the end of the uncompressed data*/)
-{
- /* TODO: implement different limits for different types of chunk.
- *
- * The caller supplies *newlength set to the maximum length of the
- * uncompressed data, but this routine allocates space for the prefix and
- * maybe a '\0' terminator too. We have to assume that 'prefix_size' is
- * limited only by the maximum chunk size.
- */
- png_alloc_size_t limit = PNG_SIZE_MAX;
-
-# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
- if (png_ptr->user_chunk_malloc_max > 0 &&
- png_ptr->user_chunk_malloc_max < limit)
- limit = png_ptr->user_chunk_malloc_max;
-# elif PNG_USER_CHUNK_MALLOC_MAX > 0
- if (PNG_USER_CHUNK_MALLOC_MAX < limit)
- limit = PNG_USER_CHUNK_MALLOC_MAX;
-# endif
-
- if (limit >= prefix_size + (terminate != 0))
- {
- int ret;
-
- limit -= prefix_size + (terminate != 0);
-
- if (limit < *newlength)
- *newlength = limit;
-
- /* Now try to claim the stream. */
- ret = png_inflate_claim(png_ptr, png_ptr->chunk_name);
-
- if (ret == Z_OK)
- {
- png_uint_32 lzsize = chunklength - prefix_size;
-
- ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
- /* input: */ png_ptr->read_buffer + prefix_size, &lzsize,
- /* output: */ NULL, newlength);
-
- if (ret == Z_STREAM_END)
- {
- /* Use 'inflateReset' here, not 'inflateReset2' because this
- * preserves the previously decided window size (otherwise it would
- * be necessary to store the previous window size.) In practice
- * this doesn't matter anyway, because png_inflate will call inflate
- * with Z_FINISH in almost all cases, so the window will not be
- * maintained.
- */
- if (inflateReset(&png_ptr->zstream) == Z_OK)
- {
- /* Because of the limit checks above we know that the new,
- * expanded, size will fit in a size_t (let alone an
- * png_alloc_size_t). Use png_malloc_base here to avoid an
- * extra OOM message.
- */
- png_alloc_size_t new_size = *newlength;
- png_alloc_size_t buffer_size = prefix_size + new_size +
- (terminate != 0);
- png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr,
- buffer_size));
-
- if (text != NULL)
- {
- ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
- png_ptr->read_buffer + prefix_size, &lzsize,
- text + prefix_size, newlength);
-
- if (ret == Z_STREAM_END)
- {
- if (new_size == *newlength)
- {
- if (terminate)
- text[prefix_size + *newlength] = 0;
-
- if (prefix_size > 0)
- memcpy(text, png_ptr->read_buffer, prefix_size);
-
- {
- png_bytep old_ptr = png_ptr->read_buffer;
-
- png_ptr->read_buffer = text;
- png_ptr->read_buffer_size = buffer_size;
- text = old_ptr; /* freed below */
- }
- }
-
- else
- {
- /* The size changed on the second read, there can be no
- * guarantee that anything is correct at this point.
- * The 'msg' pointer has been set to "unexpected end of
- * LZ stream", which is fine, but return an error code
- * that the caller won't accept.
- */
- ret = PNG_UNEXPECTED_ZLIB_RETURN;
- }
- }
-
- else if (ret == Z_OK)
- ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */
-
- /* Free the text pointer (this is the old read_buffer on
- * success)
- */
- png_free(png_ptr, text);
-
- /* This really is very benign, but it's still an error because
- * the extra space may otherwise be used as a Trojan Horse.
- */
- if (ret == Z_STREAM_END &&
- chunklength - prefix_size != lzsize)
- png_chunk_benign_error(png_ptr, "extra compressed data");
- }
-
- else
- {
- /* Out of memory allocating the buffer */
- ret = Z_MEM_ERROR;
- png_zstream_error(png_ptr, Z_MEM_ERROR);
- }
- }
-
- else
- {
- /* inflateReset failed, store the error message */
- png_zstream_error(png_ptr, ret);
-
- if (ret == Z_STREAM_END)
- ret = PNG_UNEXPECTED_ZLIB_RETURN;
- }
- }
-
- else if (ret == Z_OK)
- ret = PNG_UNEXPECTED_ZLIB_RETURN;
-
- /* Release the claimed stream */
- png_ptr->zowner = 0;
- }
-
- else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */
- ret = PNG_UNEXPECTED_ZLIB_RETURN;
-
- return ret;
- }
-
- else
- {
- /* Application/configuration limits exceeded */
- png_zstream_error(png_ptr, Z_MEM_ERROR);
- return Z_MEM_ERROR;
- }
-}
-#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
-
-#ifdef PNG_READ_iCCP_SUPPORTED
-/* Perform a partial read and decompress, producing 'avail_out' bytes and
- * reading from the current chunk as required.
- */
-static int
-png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size,
- png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size,
- int finish)
-{
- if (png_ptr->zowner == png_ptr->chunk_name)
- {
- int ret;
-
- /* next_in and avail_in must have been initialized by the caller. */
- png_ptr->zstream.next_out = next_out;
- png_ptr->zstream.avail_out = 0; /* set in the loop */
-
- do
- {
- if (png_ptr->zstream.avail_in == 0)
- {
- if (read_size > *chunk_bytes)
- read_size = (uInt)*chunk_bytes;
- *chunk_bytes -= read_size;
-
- if (read_size > 0)
- png_crc_read(png_ptr, read_buffer, read_size);
-
- png_ptr->zstream.next_in = read_buffer;
- png_ptr->zstream.avail_in = read_size;
- }
-
- if (png_ptr->zstream.avail_out == 0)
- {
- uInt avail = ZLIB_IO_MAX;
- if (avail > *out_size)
- avail = (uInt)*out_size;
- *out_size -= avail;
-
- png_ptr->zstream.avail_out = avail;
- }
-
- /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all
- * the available output is produced; this allows reading of truncated
- * streams.
- */
- ret = inflate(&png_ptr->zstream,
- *chunk_bytes > 0 ? Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH));
- }
- while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0));
-
- *out_size += png_ptr->zstream.avail_out;
- png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */
-
- /* Ensure the error message pointer is always set: */
- png_zstream_error(png_ptr, ret);
- return ret;
- }
-
- else
- {
- png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
- return Z_STREAM_ERROR;
- }
-}
-#endif
-
-/* Read and check the IDHR chunk */
-void /* PRIVATE */
-png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[13];
- png_uint_32 width, height;
- int bit_depth, color_type, compression_type, filter_type;
- int interlace_type;
-
- png_debug(1, "in png_handle_IHDR");
-
- if (png_ptr->mode & PNG_HAVE_IHDR)
- png_chunk_error(png_ptr, "out of place");
-
- /* Check the length */
- if (length != 13)
- png_chunk_error(png_ptr, "invalid");
-
- png_ptr->mode |= PNG_HAVE_IHDR;
-
- png_crc_read(png_ptr, buf, 13);
- png_crc_finish(png_ptr, 0);
-
- width = png_get_uint_31(png_ptr, buf);
- height = png_get_uint_31(png_ptr, buf + 4);
- bit_depth = buf[8];
- color_type = buf[9];
- compression_type = buf[10];
- filter_type = buf[11];
- interlace_type = buf[12];
-
- /* Set internal variables */
- png_ptr->width = width;
- png_ptr->height = height;
- png_ptr->bit_depth = (png_byte)bit_depth;
- png_ptr->interlaced = (png_byte)interlace_type;
- png_ptr->color_type = (png_byte)color_type;
-#ifdef PNG_MNG_FEATURES_SUPPORTED
- png_ptr->filter_type = (png_byte)filter_type;
-#endif
- png_ptr->compression_type = (png_byte)compression_type;
-
- /* Find number of channels */
- switch (png_ptr->color_type)
- {
- default: /* invalid, png_set_IHDR calls png_error */
- case PNG_COLOR_TYPE_GRAY:
- case PNG_COLOR_TYPE_PALETTE:
- png_ptr->channels = 1;
- break;
-
- case PNG_COLOR_TYPE_RGB:
- png_ptr->channels = 3;
- break;
-
- case PNG_COLOR_TYPE_GRAY_ALPHA:
- png_ptr->channels = 2;
- break;
-
- case PNG_COLOR_TYPE_RGB_ALPHA:
- png_ptr->channels = 4;
- break;
- }
-
- /* Set up other useful info */
- png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
- png_ptr->channels);
- png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
- png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
- png_debug1(3, "channels = %d", png_ptr->channels);
- png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes);
- png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
- color_type, interlace_type, compression_type, filter_type);
-}
-
-/* Read and check the palette */
-void /* PRIVATE */
-png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_color palette[PNG_MAX_PALETTE_LENGTH];
- int num, i;
-#ifdef PNG_POINTER_INDEXING_SUPPORTED
- png_colorp pal_ptr;
-#endif
-
- png_debug(1, "in png_handle_PLTE");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- /* Moved to before the 'after IDAT' check below because otherwise duplicate
- * PLTE chunks are potentially ignored (the spec says there shall not be more
- * than one PLTE, the error is not treated as benign, so this check trumps
- * the requirement that PLTE appears before IDAT.)
- */
- else if (png_ptr->mode & PNG_HAVE_PLTE)
- png_chunk_error(png_ptr, "duplicate");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- /* This is benign because the non-benign error happened before, when an
- * IDAT was encountered in a color-mapped image with no PLTE.
- */
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- png_ptr->mode |= PNG_HAVE_PLTE;
-
- if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "ignored in grayscale PNG");
- return;
- }
-
-#ifndef PNG_READ_OPT_PLTE_SUPPORTED
- if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-#endif
-
- if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
- {
- png_crc_finish(png_ptr, length);
-
- if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
- png_chunk_benign_error(png_ptr, "invalid");
-
- else
- png_chunk_error(png_ptr, "invalid");
-
- return;
- }
-
- /* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */
- num = (int)length / 3;
-
-#ifdef PNG_POINTER_INDEXING_SUPPORTED
- for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
- {
- png_byte buf[3];
-
- png_crc_read(png_ptr, buf, 3);
- pal_ptr->red = buf[0];
- pal_ptr->green = buf[1];
- pal_ptr->blue = buf[2];
- }
-#else
- for (i = 0; i < num; i++)
- {
- png_byte buf[3];
-
- png_crc_read(png_ptr, buf, 3);
- /* Don't depend upon png_color being any order */
- palette[i].red = buf[0];
- palette[i].green = buf[1];
- palette[i].blue = buf[2];
- }
-#endif
-
- /* If we actually need the PLTE chunk (ie for a paletted image), we do
- * whatever the normal CRC configuration tells us. However, if we
- * have an RGB image, the PLTE can be considered ancillary, so
- * we will act as though it is.
- */
-#ifndef PNG_READ_OPT_PLTE_SUPPORTED
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
-#endif
- {
- png_crc_finish(png_ptr, 0);
- }
-
-#ifndef PNG_READ_OPT_PLTE_SUPPORTED
- else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */
- {
- /* If we don't want to use the data from an ancillary chunk,
- * we have two options: an error abort, or a warning and we
- * ignore the data in this chunk (which should be OK, since
- * it's considered ancillary for a RGB or RGBA image).
- *
- * IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the
- * chunk type to determine whether to check the ancillary or the critical
- * flags.
- */
- if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
- {
- if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
- {
- png_chunk_benign_error(png_ptr, "CRC error");
- }
-
- else
- {
- png_chunk_warning(png_ptr, "CRC error");
- return;
- }
- }
-
- /* Otherwise, we (optionally) emit a warning and use the chunk. */
- else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
- {
- png_chunk_warning(png_ptr, "CRC error");
- }
- }
-#endif
-
- /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its
- * own copy of the palette. This has the side effect that when png_start_row
- * is called (this happens after any call to png_read_update_info) the
- * info_ptr palette gets changed. This is extremely unexpected and
- * confusing.
- *
- * Fix this by not sharing the palette in this way.
- */
- png_set_PLTE(png_ptr, info_ptr, palette, num);
-
- /* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before
- * IDAT. Prior to 1.6.0 this was not checked; instead the code merely
- * checked the apparent validity of a tRNS chunk inserted before PLTE on a
- * palette PNG. 1.6.0 attempts to rigorously follow the standard and
- * therefore does a benign error if the erroneous condition is detected *and*
- * cancels the tRNS if the benign error returns. The alternative is to
- * amend the standard since it would be rather hypocritical of the standards
- * maintainers to ignore it.
- */
-#ifdef PNG_READ_tRNS_SUPPORTED
- if (png_ptr->num_trans > 0 ||
- (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0))
- {
- /* Cancel this because otherwise it would be used if the transforms
- * require it. Don't cancel the 'valid' flag because this would prevent
- * detection of duplicate chunks.
- */
- png_ptr->num_trans = 0;
-
- if (info_ptr != NULL)
- info_ptr->num_trans = 0;
-
- png_chunk_benign_error(png_ptr, "tRNS must be after");
- }
-#endif
-
-#ifdef PNG_READ_hIST_SUPPORTED
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0)
- png_chunk_benign_error(png_ptr, "hIST must be after");
-#endif
-
-#ifdef PNG_READ_bKGD_SUPPORTED
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0)
- png_chunk_benign_error(png_ptr, "bKGD must be after");
-#endif
-}
-
-void /* PRIVATE */
-png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_debug(1, "in png_handle_IEND");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
- png_chunk_error(png_ptr, "out of place");
-
- png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
-
- png_crc_finish(png_ptr, length);
-
- if (length != 0)
- png_chunk_benign_error(png_ptr, "invalid");
-
- PNG_UNUSED(info_ptr)
-}
-
-#ifdef PNG_READ_gAMA_SUPPORTED
-void /* PRIVATE */
-png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_fixed_point igamma;
- png_byte buf[4];
-
- png_debug(1, "in png_handle_gAMA");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (length != 4)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 4);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- igamma = png_get_fixed_point(NULL, buf);
-
- png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma);
- png_colorspace_sync(png_ptr, info_ptr);
-}
-#endif
-
-#ifdef PNG_READ_sBIT_SUPPORTED
-void /* PRIVATE */
-png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- unsigned int truelen;
- png_byte buf[4];
-
- png_debug(1, "in png_handle_sBIT");
-
- buf[0] = buf[1] = buf[2] = buf[3] = 0;
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- truelen = 3;
-
- else
- truelen = png_ptr->channels;
-
- if (length != truelen || length > 4)
- {
- png_chunk_benign_error(png_ptr, "invalid");
- png_crc_finish(png_ptr, length);
- return;
- }
-
- png_crc_read(png_ptr, buf, truelen);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
- {
- png_ptr->sig_bit.red = buf[0];
- png_ptr->sig_bit.green = buf[1];
- png_ptr->sig_bit.blue = buf[2];
- png_ptr->sig_bit.alpha = buf[3];
- }
-
- else
- {
- png_ptr->sig_bit.gray = buf[0];
- png_ptr->sig_bit.red = buf[0];
- png_ptr->sig_bit.green = buf[0];
- png_ptr->sig_bit.blue = buf[0];
- png_ptr->sig_bit.alpha = buf[1];
- }
-
- png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
-}
-#endif
-
-#ifdef PNG_READ_cHRM_SUPPORTED
-void /* PRIVATE */
-png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[32];
- png_xy xy;
-
- png_debug(1, "in png_handle_cHRM");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (length != 32)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 32);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- xy.whitex = png_get_fixed_point(NULL, buf);
- xy.whitey = png_get_fixed_point(NULL, buf + 4);
- xy.redx = png_get_fixed_point(NULL, buf + 8);
- xy.redy = png_get_fixed_point(NULL, buf + 12);
- xy.greenx = png_get_fixed_point(NULL, buf + 16);
- xy.greeny = png_get_fixed_point(NULL, buf + 20);
- xy.bluex = png_get_fixed_point(NULL, buf + 24);
- xy.bluey = png_get_fixed_point(NULL, buf + 28);
-
- if (xy.whitex == PNG_FIXED_ERROR ||
- xy.whitey == PNG_FIXED_ERROR ||
- xy.redx == PNG_FIXED_ERROR ||
- xy.redy == PNG_FIXED_ERROR ||
- xy.greenx == PNG_FIXED_ERROR ||
- xy.greeny == PNG_FIXED_ERROR ||
- xy.bluex == PNG_FIXED_ERROR ||
- xy.bluey == PNG_FIXED_ERROR)
- {
- png_chunk_benign_error(png_ptr, "invalid values");
- return;
- }
-
- /* If a colorspace error has already been output skip this chunk */
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
- return;
-
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM)
- {
- png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
- png_colorspace_sync(png_ptr, info_ptr);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
- (void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy,
- 1/*prefer cHRM values*/);
- png_colorspace_sync(png_ptr, info_ptr);
-}
-#endif
-
-#ifdef PNG_READ_sRGB_SUPPORTED
-void /* PRIVATE */
-png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte intent;
-
- png_debug(1, "in png_handle_sRGB");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (length != 1)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, &intent, 1);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* If a colorspace error has already been output skip this chunk */
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
- return;
-
- /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
- * this.
- */
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT)
- {
- png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
- png_colorspace_sync(png_ptr, info_ptr);
- png_chunk_benign_error(png_ptr, "too many profiles");
- return;
- }
-
- (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent);
- png_colorspace_sync(png_ptr, info_ptr);
-}
-#endif /* PNG_READ_sRGB_SUPPORTED */
-
-#ifdef PNG_READ_iCCP_SUPPORTED
-void /* PRIVATE */
-png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-/* Note: this does not properly handle profiles that are > 64K under DOS */
-{
- png_const_charp errmsg = NULL; /* error message output, or no error */
- int finished = 0; /* crc checked */
-
- png_debug(1, "in png_handle_iCCP");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- /* Consistent with all the above colorspace handling an obviously *invalid*
- * chunk is just ignored, so does not invalidate the color space. An
- * alternative is to set the 'invalid' flags at the start of this routine
- * and only clear them in they were not set before and all the tests pass.
- * The minimum 'deflate' stream is assumed to be just the 2 byte header and 4
- * byte checksum. The keyword must be one character and there is a
- * terminator (0) byte and the compression method.
- */
- if (length < 9)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "too short");
- return;
- }
-
- /* If a colorspace error has already been output skip this chunk */
- if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
- * this.
- */
- if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0)
- {
- uInt read_length, keyword_length;
- char keyword[81];
-
- /* Find the keyword; the keyword plus separator and compression method
- * bytes can be at most 81 characters long.
- */
- read_length = 81; /* maximum */
- if (read_length > length)
- read_length = (uInt)length;
-
- png_crc_read(png_ptr, (png_bytep)keyword, read_length);
- length -= read_length;
-
- keyword_length = 0;
- while (keyword_length < 80 && keyword_length < read_length &&
- keyword[keyword_length] != 0)
- ++keyword_length;
-
- /* TODO: make the keyword checking common */
- if (keyword_length >= 1 && keyword_length <= 79)
- {
- /* We only understand '0' compression - deflate - so if we get a
- * different value we can't safely decode the chunk.
- */
- if (keyword_length+1 < read_length &&
- keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE)
- {
- read_length -= keyword_length+2;
-
- if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK)
- {
- Byte profile_header[132];
- Byte local_buffer[PNG_INFLATE_BUF_SIZE];
- png_alloc_size_t size = (sizeof profile_header);
-
- png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2);
- png_ptr->zstream.avail_in = read_length;
- (void)png_inflate_read(png_ptr, local_buffer,
- (sizeof local_buffer), &length, profile_header, &size,
- 0/*finish: don't, because the output is too small*/);
-
- if (size == 0)
- {
- /* We have the ICC profile header; do the basic header checks.
- */
- const png_uint_32 profile_length =
- png_get_uint_32(profile_header);
-
- if (png_icc_check_length(png_ptr, &png_ptr->colorspace,
- keyword, profile_length))
- {
- /* The length is apparently ok, so we can check the 132
- * byte header.
- */
- if (png_icc_check_header(png_ptr, &png_ptr->colorspace,
- keyword, profile_length, profile_header,
- png_ptr->color_type))
- {
- /* Now read the tag table; a variable size buffer is
- * needed at this point, allocate one for the whole
- * profile. The header check has already validated
- * that none of these stuff will overflow.
- */
- const png_uint_32 tag_count = png_get_uint_32(
- profile_header+128);
- png_bytep profile = png_read_buffer(png_ptr,
- profile_length, 2/*silent*/);
-
- if (profile != NULL)
- {
- memcpy(profile, profile_header,
- (sizeof profile_header));
-
- size = 12 * tag_count;
-
- (void)png_inflate_read(png_ptr, local_buffer,
- (sizeof local_buffer), &length,
- profile + (sizeof profile_header), &size, 0);
-
- /* Still expect a a buffer error because we expect
- * there to be some tag data!
- */
- if (size == 0)
- {
- if (png_icc_check_tag_table(png_ptr,
- &png_ptr->colorspace, keyword, profile_length,
- profile))
- {
- /* The profile has been validated for basic
- * security issues, so read the whole thing in.
- */
- size = profile_length - (sizeof profile_header)
- - 12 * tag_count;
-
- (void)png_inflate_read(png_ptr, local_buffer,
- (sizeof local_buffer), &length,
- profile + (sizeof profile_header) +
- 12 * tag_count, &size, 1/*finish*/);
-
- if (length > 0 && !(png_ptr->flags &
- PNG_FLAG_BENIGN_ERRORS_WARN))
- errmsg = "extra compressed data";
-
- /* But otherwise allow extra data: */
- else if (size == 0)
- {
- if (length > 0)
- {
- /* This can be handled completely, so
- * keep going.
- */
- png_chunk_warning(png_ptr,
- "extra compressed data");
- }
-
- png_crc_finish(png_ptr, length);
- finished = 1;
-
-# ifdef PNG_sRGB_SUPPORTED
- /* Check for a match against sRGB */
- png_icc_set_sRGB(png_ptr,
- &png_ptr->colorspace, profile,
- png_ptr->zstream.adler);
-# endif
-
- /* Steal the profile for info_ptr. */
- if (info_ptr != NULL)
- {
- png_free_data(png_ptr, info_ptr,
- PNG_FREE_ICCP, 0);
-
- info_ptr->iccp_name = png_voidcast(char*,
- png_malloc_base(png_ptr,
- keyword_length+1));
- if (info_ptr->iccp_name != NULL)
- {
- memcpy(info_ptr->iccp_name, keyword,
- keyword_length+1);
- info_ptr->iccp_proflen =
- profile_length;
- info_ptr->iccp_profile = profile;
- png_ptr->read_buffer = NULL; /*steal*/
- info_ptr->free_me |= PNG_FREE_ICCP;
- info_ptr->valid |= PNG_INFO_iCCP;
- }
-
- else
- {
- png_ptr->colorspace.flags |=
- PNG_COLORSPACE_INVALID;
- errmsg = "out of memory";
- }
- }
-
- /* else the profile remains in the read
- * buffer which gets reused for subsequent
- * chunks.
- */
-
- if (info_ptr != NULL)
- png_colorspace_sync(png_ptr, info_ptr);
-
- if (errmsg == NULL)
- {
- png_ptr->zowner = 0;
- return;
- }
- }
-
- else if (size > 0)
- errmsg = "truncated";
-
- else
- errmsg = png_ptr->zstream.msg;
- }
-
- /* else png_icc_check_tag_table output an error */
- }
-
- else /* profile truncated */
- errmsg = png_ptr->zstream.msg;
- }
-
- else
- errmsg = "out of memory";
- }
-
- /* else png_icc_check_header output an error */
- }
-
- /* else png_icc_check_length output an error */
- }
-
- else /* profile truncated */
- errmsg = png_ptr->zstream.msg;
-
- /* Release the stream */
- png_ptr->zowner = 0;
- }
-
- else /* png_inflate_claim failed */
- errmsg = png_ptr->zstream.msg;
- }
-
- else
- errmsg = "bad compression method"; /* or missing */
- }
-
- else
- errmsg = "bad keyword";
- }
-
- else
- errmsg = "too many profiles";
-
- /* Failure: the reason is in 'errmsg' */
- if (!finished)
- png_crc_finish(png_ptr, length);
-
- png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
- png_colorspace_sync(png_ptr, info_ptr);
- if (errmsg != NULL) /* else already output */
- png_chunk_benign_error(png_ptr, errmsg);
-}
-#endif /* PNG_READ_iCCP_SUPPORTED */
-
-#ifdef PNG_READ_sPLT_SUPPORTED
-void /* PRIVATE */
-png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-/* Note: this does not properly handle chunks that are > 64K under DOS */
-{
- png_bytep entry_start, buffer;
- png_sPLT_t new_palette;
- png_sPLT_entryp pp;
- png_uint_32 data_length;
- int entry_size, i;
- png_uint_32 skip = 0;
- png_uint_32 dl;
- png_size_t max_dl;
-
- png_debug(1, "in png_handle_sPLT");
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_cache_max != 0)
- {
- if (png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- if (--png_ptr->user_chunk_cache_max == 1)
- {
- png_warning(png_ptr, "No space in chunk cache for sPLT");
- png_crc_finish(png_ptr, length);
- return;
- }
- }
-#endif
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
-#ifdef PNG_MAX_MALLOC_64K
- if (length > 65535U)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "too large to fit in memory");
- return;
- }
-#endif
-
- buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
- if (buffer == NULL)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
-
- /* WARNING: this may break if size_t is less than 32 bits; it is assumed
- * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
- * potential breakage point if the types in pngconf.h aren't exactly right.
- */
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, skip))
- return;
-
- buffer[length] = 0;
-
- for (entry_start = buffer; *entry_start; entry_start++)
- /* Empty loop to find end of name */ ;
-
- ++entry_start;
-
- /* A sample depth should follow the separator, and we should be on it */
- if (entry_start > buffer + length - 2)
- {
- png_warning(png_ptr, "malformed sPLT chunk");
- return;
- }
-
- new_palette.depth = *entry_start++;
- entry_size = (new_palette.depth == 8 ? 6 : 10);
- /* This must fit in a png_uint_32 because it is derived from the original
- * chunk data length.
- */
- data_length = length - (png_uint_32)(entry_start - buffer);
-
- /* Integrity-check the data length */
- if (data_length % entry_size)
- {
- png_warning(png_ptr, "sPLT chunk has bad length");
- return;
- }
-
- dl = (png_int_32)(data_length / entry_size);
- max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry));
-
- if (dl > max_dl)
- {
- png_warning(png_ptr, "sPLT chunk too long");
- return;
- }
-
- new_palette.nentries = (png_int_32)(data_length / entry_size);
-
- new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
- png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry)));
-
- if (new_palette.entries == NULL)
- {
- png_warning(png_ptr, "sPLT chunk requires too much memory");
- return;
- }
-
-#ifdef PNG_POINTER_INDEXING_SUPPORTED
- for (i = 0; i < new_palette.nentries; i++)
- {
- pp = new_palette.entries + i;
-
- if (new_palette.depth == 8)
- {
- pp->red = *entry_start++;
- pp->green = *entry_start++;
- pp->blue = *entry_start++;
- pp->alpha = *entry_start++;
- }
-
- else
- {
- pp->red = png_get_uint_16(entry_start); entry_start += 2;
- pp->green = png_get_uint_16(entry_start); entry_start += 2;
- pp->blue = png_get_uint_16(entry_start); entry_start += 2;
- pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
- }
-
- pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
- }
-#else
- pp = new_palette.entries;
-
- for (i = 0; i < new_palette.nentries; i++)
- {
-
- if (new_palette.depth == 8)
- {
- pp[i].red = *entry_start++;
- pp[i].green = *entry_start++;
- pp[i].blue = *entry_start++;
- pp[i].alpha = *entry_start++;
- }
-
- else
- {
- pp[i].red = png_get_uint_16(entry_start); entry_start += 2;
- pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
- pp[i].blue = png_get_uint_16(entry_start); entry_start += 2;
- pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
- }
-
- pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2;
- }
-#endif
-
- /* Discard all chunk data except the name and stash that */
- new_palette.name = (png_charp)buffer;
-
- png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
-
- png_free(png_ptr, new_palette.entries);
-}
-#endif /* PNG_READ_sPLT_SUPPORTED */
-
-#ifdef PNG_READ_tRNS_SUPPORTED
-void /* PRIVATE */
-png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
-
- png_debug(1, "in png_handle_tRNS");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
- {
- png_byte buf[2];
-
- if (length != 2)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 2);
- png_ptr->num_trans = 1;
- png_ptr->trans_color.gray = png_get_uint_16(buf);
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
- {
- png_byte buf[6];
-
- if (length != 6)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, length);
- png_ptr->num_trans = 1;
- png_ptr->trans_color.red = png_get_uint_16(buf);
- png_ptr->trans_color.green = png_get_uint_16(buf + 2);
- png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (!(png_ptr->mode & PNG_HAVE_PLTE))
- {
- /* TODO: is this actually an error in the ISO spec? */
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- if (length > png_ptr->num_palette || length > PNG_MAX_PALETTE_LENGTH ||
- length == 0)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, readbuf, length);
- png_ptr->num_trans = (png_uint_16)length;
- }
-
- else
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid with alpha channel");
- return;
- }
-
- if (png_crc_finish(png_ptr, 0))
- {
- png_ptr->num_trans = 0;
- return;
- }
-
- /* TODO: this is a horrible side effect in the palette case because the
- * png_struct ends up with a pointer to the tRNS buffer owned by the
- * png_info. Fix this.
- */
- png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
- &(png_ptr->trans_color));
-}
-#endif
-
-#ifdef PNG_READ_bKGD_SUPPORTED
-void /* PRIVATE */
-png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- unsigned int truelen;
- png_byte buf[6];
- png_color_16 background;
-
- png_debug(1, "in png_handle_bKGD");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if ((png_ptr->mode & PNG_HAVE_IDAT) ||
- (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
- !(png_ptr->mode & PNG_HAVE_PLTE)))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- truelen = 1;
-
- else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
- truelen = 6;
-
- else
- truelen = 2;
-
- if (length != truelen)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, truelen);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* We convert the index value into RGB components so that we can allow
- * arbitrary RGB values for background when we have transparency, and
- * so it is easy to determine the RGB values of the background color
- * from the info_ptr struct.
- */
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- background.index = buf[0];
-
- if (info_ptr && info_ptr->num_palette)
- {
- if (buf[0] >= info_ptr->num_palette)
- {
- png_chunk_benign_error(png_ptr, "invalid index");
- return;
- }
-
- background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
- background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
- background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
- }
-
- else
- background.red = background.green = background.blue = 0;
-
- background.gray = 0;
- }
-
- else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
- {
- background.index = 0;
- background.red =
- background.green =
- background.blue =
- background.gray = png_get_uint_16(buf);
- }
-
- else
- {
- background.index = 0;
- background.red = png_get_uint_16(buf);
- background.green = png_get_uint_16(buf + 2);
- background.blue = png_get_uint_16(buf + 4);
- background.gray = 0;
- }
-
- png_set_bKGD(png_ptr, info_ptr, &background);
-}
-#endif
-
-#ifdef PNG_READ_hIST_SUPPORTED
-void /* PRIVATE */
-png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- unsigned int num, i;
- png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
-
- png_debug(1, "in png_handle_hIST");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if ((png_ptr->mode & PNG_HAVE_IDAT) || !(png_ptr->mode & PNG_HAVE_PLTE))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- num = length / 2 ;
-
- if (num != png_ptr->num_palette || num > PNG_MAX_PALETTE_LENGTH)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- for (i = 0; i < num; i++)
- {
- png_byte buf[2];
-
- png_crc_read(png_ptr, buf, 2);
- readbuf[i] = png_get_uint_16(buf);
- }
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- png_set_hIST(png_ptr, info_ptr, readbuf);
-}
-#endif
-
-#ifdef PNG_READ_pHYs_SUPPORTED
-void /* PRIVATE */
-png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[9];
- png_uint_32 res_x, res_y;
- int unit_type;
-
- png_debug(1, "in png_handle_pHYs");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (length != 9)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 9);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- res_x = png_get_uint_32(buf);
- res_y = png_get_uint_32(buf + 4);
- unit_type = buf[8];
- png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
-}
-#endif
-
-#ifdef PNG_READ_oFFs_SUPPORTED
-void /* PRIVATE */
-png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[9];
- png_int_32 offset_x, offset_y;
- int unit_type;
-
- png_debug(1, "in png_handle_oFFs");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (length != 9)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 9);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- offset_x = png_get_int_32(buf);
- offset_y = png_get_int_32(buf + 4);
- unit_type = buf[8];
- png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
-}
-#endif
-
-#ifdef PNG_READ_pCAL_SUPPORTED
-/* Read the pCAL chunk (described in the PNG Extensions document) */
-void /* PRIVATE */
-png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_int_32 X0, X1;
- png_byte type, nparams;
- png_bytep buffer, buf, units, endptr;
- png_charpp params;
- int i;
-
- png_debug(1, "in png_handle_pCAL");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
- length + 1);
-
- buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
-
- if (buffer == NULL)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- buffer[length] = 0; /* Null terminate the last string */
-
- png_debug(3, "Finding end of pCAL purpose string");
- for (buf = buffer; *buf; buf++)
- /* Empty loop */ ;
-
- endptr = buffer + length;
-
- /* We need to have at least 12 bytes after the purpose string
- * in order to get the parameter information.
- */
- if (endptr <= buf + 12)
- {
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
- X0 = png_get_int_32((png_bytep)buf+1);
- X1 = png_get_int_32((png_bytep)buf+5);
- type = buf[9];
- nparams = buf[10];
- units = buf + 11;
-
- png_debug(3, "Checking pCAL equation type and number of parameters");
- /* Check that we have the right number of parameters for known
- * equation types.
- */
- if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
- (type == PNG_EQUATION_BASE_E && nparams != 3) ||
- (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
- (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
- {
- png_chunk_benign_error(png_ptr, "invalid parameter count");
- return;
- }
-
- else if (type >= PNG_EQUATION_LAST)
- {
- png_chunk_benign_error(png_ptr, "unrecognized equation type");
- }
-
- for (buf = units; *buf; buf++)
- /* Empty loop to move past the units string. */ ;
-
- png_debug(3, "Allocating pCAL parameters array");
-
- params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
- nparams * (sizeof (png_charp))));
-
- if (params == NULL)
- {
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- /* Get pointers to the start of each parameter string. */
- for (i = 0; i < nparams; i++)
- {
- buf++; /* Skip the null string terminator from previous parameter. */
-
- png_debug1(3, "Reading pCAL parameter %d", i);
-
- for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++)
- /* Empty loop to move past each parameter string */ ;
-
- /* Make sure we haven't run out of data yet */
- if (buf > endptr)
- {
- png_free(png_ptr, params);
- png_chunk_benign_error(png_ptr, "invalid data");
- return;
- }
- }
-
- png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams,
- (png_charp)units, params);
-
- png_free(png_ptr, params);
-}
-#endif
-
-#ifdef PNG_READ_sCAL_SUPPORTED
-/* Read the sCAL chunk */
-void /* PRIVATE */
-png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_bytep buffer;
- png_size_t i;
- int state;
-
- png_debug(1, "in png_handle_sCAL");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of place");
- return;
- }
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- /* Need unit type, width, \0, height: minimum 4 bytes */
- else if (length < 4)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
- length + 1);
-
- buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
-
- if (buffer == NULL)
- {
- png_chunk_benign_error(png_ptr, "out of memory");
- png_crc_finish(png_ptr, length);
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
- buffer[length] = 0; /* Null terminate the last string */
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* Validate the unit. */
- if (buffer[0] != 1 && buffer[0] != 2)
- {
- png_chunk_benign_error(png_ptr, "invalid unit");
- return;
- }
-
- /* Validate the ASCII numbers, need two ASCII numbers separated by
- * a '\0' and they need to fit exactly in the chunk data.
- */
- i = 1;
- state = 0;
-
- if (!png_check_fp_number((png_const_charp)buffer, length, &state, &i) ||
- i >= length || buffer[i++] != 0)
- png_chunk_benign_error(png_ptr, "bad width format");
-
- else if (!PNG_FP_IS_POSITIVE(state))
- png_chunk_benign_error(png_ptr, "non-positive width");
-
- else
- {
- png_size_t heighti = i;
-
- state = 0;
- if (!png_check_fp_number((png_const_charp)buffer, length, &state, &i) ||
- i != length)
- png_chunk_benign_error(png_ptr, "bad height format");
-
- else if (!PNG_FP_IS_POSITIVE(state))
- png_chunk_benign_error(png_ptr, "non-positive height");
-
- else
- /* This is the (only) success case. */
- png_set_sCAL_s(png_ptr, info_ptr, buffer[0],
- (png_charp)buffer+1, (png_charp)buffer+heighti);
- }
-}
-#endif
-
-#ifdef PNG_READ_tIME_SUPPORTED
-void /* PRIVATE */
-png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_byte buf[7];
- png_time mod_time;
-
- png_debug(1, "in png_handle_tIME");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "duplicate");
- return;
- }
-
- if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
-
- if (length != 7)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "invalid");
- return;
- }
-
- png_crc_read(png_ptr, buf, 7);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- mod_time.second = buf[6];
- mod_time.minute = buf[5];
- mod_time.hour = buf[4];
- mod_time.day = buf[3];
- mod_time.month = buf[2];
- mod_time.year = png_get_uint_16(buf);
-
- png_set_tIME(png_ptr, info_ptr, &mod_time);
-}
-#endif
-
-#ifdef PNG_READ_tEXt_SUPPORTED
-/* Note: this does not properly handle chunks that are > 64K under DOS */
-void /* PRIVATE */
-png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_text text_info;
- png_bytep buffer;
- png_charp key;
- png_charp text;
- png_uint_32 skip = 0;
-
- png_debug(1, "in png_handle_tEXt");
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_cache_max != 0)
- {
- if (png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- if (--png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "no space in chunk cache");
- return;
- }
- }
-#endif
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
-
-#ifdef PNG_MAX_MALLOC_64K
- if (length > 65535U)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "too large to fit in memory");
- return;
- }
-#endif
-
- buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
-
- if (buffer == NULL)
- {
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, skip))
- return;
-
- key = (png_charp)buffer;
- key[length] = 0;
-
- for (text = key; *text; text++)
- /* Empty loop to find end of key */ ;
-
- if (text != key + length)
- text++;
-
- text_info.compression = PNG_TEXT_COMPRESSION_NONE;
- text_info.key = key;
- text_info.lang = NULL;
- text_info.lang_key = NULL;
- text_info.itxt_length = 0;
- text_info.text = text;
- text_info.text_length = strlen(text);
-
- if (png_set_text_2(png_ptr, info_ptr, &text_info, 1))
- png_warning(png_ptr, "Insufficient memory to process text chunk");
-}
-#endif
-
-#ifdef PNG_READ_zTXt_SUPPORTED
-/* Note: this does not correctly handle chunks that are > 64K under DOS */
-void /* PRIVATE */
-png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_const_charp errmsg = NULL;
- png_bytep buffer;
- png_uint_32 keyword_length;
-
- png_debug(1, "in png_handle_zTXt");
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_cache_max != 0)
- {
- if (png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- if (--png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "no space in chunk cache");
- return;
- }
- }
-#endif
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
-
- buffer = png_read_buffer(png_ptr, length, 2/*silent*/);
-
- if (buffer == NULL)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* TODO: also check that the keyword contents match the spec! */
- for (keyword_length = 0;
- keyword_length < length && buffer[keyword_length] != 0;
- ++keyword_length)
- /* Empty loop to find end of name */ ;
-
- if (keyword_length > 79 || keyword_length < 1)
- errmsg = "bad keyword";
-
- /* zTXt must have some LZ data after the keyword, although it may expand to
- * zero bytes; we need a '\0' at the end of the keyword, the compression type
- * then the LZ data:
- */
- else if (keyword_length + 3 > length)
- errmsg = "truncated";
-
- else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE)
- errmsg = "unknown compression type";
-
- else
- {
- png_alloc_size_t uncompressed_length = PNG_SIZE_MAX;
-
- /* TODO: at present png_decompress_chunk imposes a single application
- * level memory limit, this should be split to different values for iCCP
- * and text chunks.
- */
- if (png_decompress_chunk(png_ptr, length, keyword_length+2,
- &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
- {
- png_text text;
-
- /* It worked; png_ptr->read_buffer now looks like a tEXt chunk except
- * for the extra compression type byte and the fact that it isn't
- * necessarily '\0' terminated.
- */
- buffer = png_ptr->read_buffer;
- buffer[uncompressed_length+(keyword_length+2)] = 0;
-
- text.compression = PNG_TEXT_COMPRESSION_zTXt;
- text.key = (png_charp)buffer;
- text.text = (png_charp)(buffer + keyword_length+2);
- text.text_length = uncompressed_length;
- text.itxt_length = 0;
- text.lang = NULL;
- text.lang_key = NULL;
-
- if (png_set_text_2(png_ptr, info_ptr, &text, 1))
- errmsg = "insufficient memory";
- }
-
- else
- errmsg = png_ptr->zstream.msg;
- }
-
- if (errmsg != NULL)
- png_chunk_benign_error(png_ptr, errmsg);
-}
-#endif
-
-#ifdef PNG_READ_iTXt_SUPPORTED
-/* Note: this does not correctly handle chunks that are > 64K under DOS */
-void /* PRIVATE */
-png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-{
- png_const_charp errmsg = NULL;
- png_bytep buffer;
- png_uint_32 prefix_length;
-
- png_debug(1, "in png_handle_iTXt");
-
-#ifdef PNG_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_cache_max != 0)
- {
- if (png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
-
- if (--png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "no space in chunk cache");
- return;
- }
- }
-#endif
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_chunk_error(png_ptr, "missing IHDR");
-
- if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
-
- buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
-
- if (buffer == NULL)
- {
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "out of memory");
- return;
- }
-
- png_crc_read(png_ptr, buffer, length);
-
- if (png_crc_finish(png_ptr, 0))
- return;
-
- /* First the keyword. */
- for (prefix_length=0;
- prefix_length < length && buffer[prefix_length] != 0;
- ++prefix_length)
- /* Empty loop */ ;
-
- /* Perform a basic check on the keyword length here. */
- if (prefix_length > 79 || prefix_length < 1)
- errmsg = "bad keyword";
-
- /* Expect keyword, compression flag, compression type, language, translated
- * keyword (both may be empty but are 0 terminated) then the text, which may
- * be empty.
- */
- else if (prefix_length + 5 > length)
- errmsg = "truncated";
-
- else if (buffer[prefix_length+1] == 0 ||
- (buffer[prefix_length+1] == 1 &&
- buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE))
- {
- int compressed = buffer[prefix_length+1] != 0;
- png_uint_32 language_offset, translated_keyword_offset;
- png_alloc_size_t uncompressed_length = 0;
-
- /* Now the language tag */
- prefix_length += 3;
- language_offset = prefix_length;
-
- for (; prefix_length < length && buffer[prefix_length] != 0;
- ++prefix_length)
- /* Empty loop */ ;
-
- /* WARNING: the length may be invalid here, this is checked below. */
- translated_keyword_offset = ++prefix_length;
-
- for (; prefix_length < length && buffer[prefix_length] != 0;
- ++prefix_length)
- /* Empty loop */ ;
-
- /* prefix_length should now be at the trailing '\0' of the translated
- * keyword, but it may already be over the end. None of this arithmetic
- * can overflow because chunks are at most 2^31 bytes long, but on 16-bit
- * systems the available allocaton may overflow.
- */
- ++prefix_length;
-
- if (!compressed && prefix_length <= length)
- uncompressed_length = length - prefix_length;
-
- else if (compressed && prefix_length < length)
- {
- uncompressed_length = PNG_SIZE_MAX;
-
- /* TODO: at present png_decompress_chunk imposes a single application
- * level memory limit, this should be split to different values for
- * iCCP and text chunks.
- */
- if (png_decompress_chunk(png_ptr, length, prefix_length,
- &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
- buffer = png_ptr->read_buffer;
-
- else
- errmsg = png_ptr->zstream.msg;
- }
-
- else
- errmsg = "truncated";
-
- if (errmsg == NULL)
- {
- png_text text;
-
- buffer[uncompressed_length+prefix_length] = 0;
-
- if (compressed)
- text.compression = PNG_ITXT_COMPRESSION_NONE;
-
- else
- text.compression = PNG_ITXT_COMPRESSION_zTXt;
-
- text.key = (png_charp)buffer;
- text.lang = (png_charp)buffer + language_offset;
- text.lang_key = (png_charp)buffer + translated_keyword_offset;
- text.text = (png_charp)buffer + prefix_length;
- text.text_length = 0;
- text.itxt_length = uncompressed_length;
-
- if (png_set_text_2(png_ptr, info_ptr, &text, 1))
- errmsg = "insufficient memory";
- }
- }
-
- else
- errmsg = "bad compression info";
-
- if (errmsg != NULL)
- png_chunk_benign_error(png_ptr, errmsg);
-}
-#endif
-
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
-static int
-png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
-{
- png_alloc_size_t limit = PNG_SIZE_MAX;
-
- if (png_ptr->unknown_chunk.data != NULL)
- {
- png_free(png_ptr, png_ptr->unknown_chunk.data);
- png_ptr->unknown_chunk.data = NULL;
- }
-
-# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
- if (png_ptr->user_chunk_malloc_max > 0 &&
- png_ptr->user_chunk_malloc_max < limit)
- limit = png_ptr->user_chunk_malloc_max;
-
-# elif PNG_USER_CHUNK_MALLOC_MAX > 0
- if (PNG_USER_CHUNK_MALLOC_MAX < limit)
- limit = PNG_USER_CHUNK_MALLOC_MAX;
-# endif
-
- if (length <= limit)
- {
- PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
- /* The following is safe because of the PNG_SIZE_MAX init above */
- png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/;
- /* 'mode' is a flag array, only the bottom four bits matter here */
- png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/;
-
- if (length == 0)
- png_ptr->unknown_chunk.data = NULL;
-
- else
- {
- /* Do a 'warn' here - it is handled below. */
- png_ptr->unknown_chunk.data = png_voidcast(png_bytep,
- png_malloc_warn(png_ptr, length));
- }
- }
-
- if (png_ptr->unknown_chunk.data == NULL && length > 0)
- {
- /* This is benign because we clean up correctly */
- png_crc_finish(png_ptr, length);
- png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits");
- return 0;
- }
-
- else
- {
- if (length > 0)
- png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
- png_crc_finish(png_ptr, 0);
- return 1;
- }
-}
-#endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
-
-/* Handle an unknown, or known but disabled, chunk */
-void /* PRIVATE */
-png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
- png_uint_32 length, int keep)
-{
- int handled = 0; /* the chunk was handled */
-
- png_debug(1, "in png_handle_unknown");
-
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
- /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
- * the bug which meant that setting a non-default behavior for a specific
- * chunk would be ignored (the default was always used unless a user
- * callback was installed).
- *
- * 'keep' is the value from the png_chunk_unknown_handling, the setting for
- * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it
- * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here.
- * This is just an optimization to avoid multiple calls to the lookup
- * function.
- */
-# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
- keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
-# endif
-# endif
-
- /* One of the following methods will read the chunk or skip it (at least one
- * of these is always defined because this is the only way to switch on
- * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
- */
-# ifdef PNG_READ_USER_CHUNKS_SUPPORTED
- /* The user callback takes precedence over the chunk keep value, but the
- * keep value is still required to validate a save of a critical chunk.
- */
- if (png_ptr->read_user_chunk_fn != NULL)
- {
- if (png_cache_unknown_chunk(png_ptr, length))
- {
- /* Callback to user unknown chunk handler */
- int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr,
- &png_ptr->unknown_chunk);
-
- /* ret is:
- * negative: An error occured, png_chunk_error will be called.
- * zero: The chunk was not handled, the chunk will be discarded
- * unless png_set_keep_unknown_chunks has been used to set
- * a 'keep' behavior for this particular chunk, in which
- * case that will be used. A critical chunk will cause an
- * error at this point unless it is to be saved.
- * positive: The chunk was handled, libpng will ignore/discard it.
- */
- if (ret < 0)
- png_chunk_error(png_ptr, "error in user chunk");
-
- else if (ret == 0)
- {
- /* If the keep value is 'default' or 'never' override it, but
- * still error out on critical chunks unless the keep value is
- * 'always' While this is weird it is the behavior in 1.4.12.
- * A possible improvement would be to obey the value set for the
- * chunk, but this would be an API change that would probably
- * damage some applications.
- *
- * The png_app_warning below catches the case that matters, where
- * the application has not set specific save or ignore for this
- * chunk or global save or ignore.
- */
- if (keep < PNG_HANDLE_CHUNK_IF_SAFE)
- {
-# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
- if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE)
- {
- png_chunk_warning(png_ptr, "Saving unknown chunk:");
- png_app_warning(png_ptr,
- "forcing save of an unhandled chunk;"
- " please call png_set_keep_unknown_chunks");
- /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */
- }
-# endif
- keep = PNG_HANDLE_CHUNK_IF_SAFE;
- }
- }
-
- else /* chunk was handled */
- {
- handled = 1;
- /* Critical chunks can be safely discarded at this point. */
- keep = PNG_HANDLE_CHUNK_NEVER;
- }
- }
-
- else
- keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */
- }
-
- else
- /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */
-# endif /* PNG_READ_USER_CHUNKS_SUPPORTED */
-
-# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
- {
- /* keep is currently just the per-chunk setting, if there was no
- * setting change it to the global default now (not that this may
- * still be AS_DEFAULT) then obtain the cache of the chunk if required,
- * if not simply skip the chunk.
- */
- if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
- keep = png_ptr->unknown_default;
-
- if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
- (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
- PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
- {
- if (!png_cache_unknown_chunk(png_ptr, length))
- keep = PNG_HANDLE_CHUNK_NEVER;
- }
-
- else
- png_crc_finish(png_ptr, length);
- }
-# else
-# ifndef PNG_READ_USER_CHUNKS_SUPPORTED
-# error no method to support READ_UNKNOWN_CHUNKS
-# endif
-
- {
- /* If here there is no read callback pointer set and no support is
- * compiled in to just save the unknown chunks, so simply skip this
- * chunk. If 'keep' is something other than AS_DEFAULT or NEVER then
- * the app has erroneously asked for unknown chunk saving when there
- * is no support.
- */
- if (keep > PNG_HANDLE_CHUNK_NEVER)
- png_app_error(png_ptr, "no unknown chunk support available");
-
- png_crc_finish(png_ptr, length);
- }
-# endif
-
-# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
- /* Now store the chunk in the chunk list if appropriate, and if the limits
- * permit it.
- */
- if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
- (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
- PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
- {
-# ifdef PNG_USER_LIMITS_SUPPORTED
- switch (png_ptr->user_chunk_cache_max)
- {
- case 2:
- png_ptr->user_chunk_cache_max = 1;
- png_chunk_benign_error(png_ptr, "no space in chunk cache");
- /* FALL THROUGH */
- case 1:
- /* NOTE: prior to 1.6.0 this case resulted in an unknown critical
- * chunk being skipped, now there will be a hard error below.
- */
- break;
-
- default: /* not at limit */
- --(png_ptr->user_chunk_cache_max);
- /* FALL THROUGH */
- case 0: /* no limit */
-# endif /* PNG_USER_LIMITS_SUPPORTED */
- /* Here when the limit isn't reached or when limits are compiled
- * out; store the chunk.
- */
- png_set_unknown_chunks(png_ptr, info_ptr,
- &png_ptr->unknown_chunk, 1);
- handled = 1;
-# ifdef PNG_USER_LIMITS_SUPPORTED
- break;
- }
-# endif
- }
-# else /* no store support! */
- PNG_UNUSED(info_ptr)
-# error untested code (reading unknown chunks with no store support)
-# endif
-
- /* Regardless of the error handling below the cached data (if any) can be
- * freed now. Notice that the data is not freed if there is a png_error, but
- * it will be freed by destroy_read_struct.
- */
- if (png_ptr->unknown_chunk.data != NULL)
- png_free(png_ptr, png_ptr->unknown_chunk.data);
- png_ptr->unknown_chunk.data = NULL;
-
-#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
- /* There is no support to read an unknown chunk, so just skip it. */
- png_crc_finish(png_ptr, length);
- PNG_UNUSED(info_ptr)
- PNG_UNUSED(keep)
-#endif /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
-
- /* Check for unhandled critical chunks */
- if (!handled && PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
- png_chunk_error(png_ptr, "unhandled critical chunk");
-}
-
-/* This function is called to verify that a chunk name is valid.
- * This function can't have the "critical chunk check" incorporated
- * into it, since in the future we will need to be able to call user
- * functions to handle unknown critical chunks after we check that
- * the chunk name itself is valid.
- */
-
-/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is:
- *
- * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
- */
-
-void /* PRIVATE */
-png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name)
-{
- int i;
-
- png_debug(1, "in png_check_chunk_name");
-
- for (i=1; i<=4; ++i)
- {
- int c = chunk_name & 0xff;
-
- if (c < 65 || c > 122 || (c > 90 && c < 97))
- png_chunk_error(png_ptr, "invalid chunk type");
-
- chunk_name >>= 8;
- }
-}
-
-/* Combines the row recently read in with the existing pixels in the row. This
- * routine takes care of alpha and transparency if requested. This routine also
- * handles the two methods of progressive display of interlaced images,
- * depending on the 'display' value; if 'display' is true then the whole row
- * (dp) is filled from the start by replicating the available pixels. If
- * 'display' is false only those pixels present in the pass are filled in.
- */
-void /* PRIVATE */
-png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
-{
- unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
- png_const_bytep sp = png_ptr->row_buf + 1;
- png_uint_32 row_width = png_ptr->width;
- unsigned int pass = png_ptr->pass;
- png_bytep end_ptr = 0;
- png_byte end_byte = 0;
- unsigned int end_mask;
-
- png_debug(1, "in png_combine_row");
-
- /* Added in 1.5.6: it should not be possible to enter this routine until at
- * least one row has been read from the PNG data and transformed.
- */
- if (pixel_depth == 0)
- png_error(png_ptr, "internal row logic error");
-
- /* Added in 1.5.4: the pixel depth should match the information returned by
- * any call to png_read_update_info at this point. Do not continue if we got
- * this wrong.
- */
- if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
- PNG_ROWBYTES(pixel_depth, row_width))
- png_error(png_ptr, "internal row size calculation error");
-
- /* Don't expect this to ever happen: */
- if (row_width == 0)
- png_error(png_ptr, "internal row width error");
-
- /* Preserve the last byte in cases where only part of it will be overwritten,
- * the multiply below may overflow, we don't care because ANSI-C guarantees
- * we get the low bits.
- */
- end_mask = (pixel_depth * row_width) & 7;
- if (end_mask != 0)
- {
- /* end_ptr == NULL is a flag to say do nothing */
- end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1;
- end_byte = *end_ptr;
-# ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (png_ptr->transformations & PNG_PACKSWAP) /* little-endian byte */
- end_mask = 0xff << end_mask;
-
- else /* big-endian byte */
-# endif
- end_mask = 0xff >> end_mask;
- /* end_mask is now the bits to *keep* from the destination row */
- }
-
- /* For non-interlaced images this reduces to a memcpy(). A memcpy()
- * will also happen if interlacing isn't supported or if the application
- * does not call png_set_interlace_handling(). In the latter cases the
- * caller just gets a sequence of the unexpanded rows from each interlace
- * pass.
- */
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE) &&
- pass < 6 && (display == 0 ||
- /* The following copies everything for 'display' on passes 0, 2 and 4. */
- (display == 1 && (pass & 1) != 0)))
- {
- /* Narrow images may have no bits in a pass; the caller should handle
- * this, but this test is cheap:
- */
- if (row_width <= PNG_PASS_START_COL(pass))
- return;
-
- if (pixel_depth < 8)
- {
- /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit
- * into 32 bits, then a single loop over the bytes using the four byte
- * values in the 32-bit mask can be used. For the 'display' option the
- * expanded mask may also not require any masking within a byte. To
- * make this work the PACKSWAP option must be taken into account - it
- * simply requires the pixels to be reversed in each byte.
- *
- * The 'regular' case requires a mask for each of the first 6 passes,
- * the 'display' case does a copy for the even passes in the range
- * 0..6. This has already been handled in the test above.
- *
- * The masks are arranged as four bytes with the first byte to use in
- * the lowest bits (little-endian) regardless of the order (PACKSWAP or
- * not) of the pixels in each byte.
- *
- * NOTE: the whole of this logic depends on the caller of this function
- * only calling it on rows appropriate to the pass. This function only
- * understands the 'x' logic; the 'y' logic is handled by the caller.
- *
- * The following defines allow generation of compile time constant bit
- * masks for each pixel depth and each possibility of swapped or not
- * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index,
- * is in the range 0..7; and the result is 1 if the pixel is to be
- * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B'
- * for the block method.
- *
- * With some compilers a compile time expression of the general form:
- *
- * (shift >= 32) ? (a >> (shift-32)) : (b >> shift)
- *
- * Produces warnings with values of 'shift' in the range 33 to 63
- * because the right hand side of the ?: expression is evaluated by
- * the compiler even though it isn't used. Microsoft Visual C (various
- * versions) and the Intel C compiler are known to do this. To avoid
- * this the following macros are used in 1.5.6. This is a temporary
- * solution to avoid destabilizing the code during the release process.
- */
-# if PNG_USE_COMPILE_TIME_MASKS
-# define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
-# define PNG_LSL(x,s) ((x)<<((s) & 0x1f))
-# else
-# define PNG_LSR(x,s) ((x)>>(s))
-# define PNG_LSL(x,s) ((x)<<(s))
-# endif
-# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\
- PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1)
-# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\
- PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1)
-
- /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is
- * little endian - the first pixel is at bit 0 - however the extra
- * parameter 's' can be set to cause the mask position to be swapped
- * within each byte, to match the PNG format. This is done by XOR of
- * the shift with 7, 6 or 4 for bit depths 1, 2 and 4.
- */
-# define PIXEL_MASK(p,x,d,s) \
- (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0))))
-
- /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask.
- */
-# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
-# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
-
- /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp
- * cases the result needs replicating, for the 4-bpp case the above
- * generates a full 32 bits.
- */
-# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1)))
-
-# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\
- S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\
- S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d)
-
-# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\
- B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\
- B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d)
-
-#if PNG_USE_COMPILE_TIME_MASKS
- /* Utility macros to construct all the masks for a depth/swap
- * combination. The 's' parameter says whether the format is PNG
- * (big endian bytes) or not. Only the three odd-numbered passes are
- * required for the display/block algorithm.
- */
-# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
- S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
-
-# define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) }
-
-# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
-
- /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and
- * then pass:
- */
- static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] =
- {
- /* Little-endian byte masks for PACKSWAP */
- { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) },
- /* Normal (big-endian byte) masks - PNG format */
- { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) }
- };
-
- /* display_mask has only three entries for the odd passes, so index by
- * pass>>1.
- */
- static PNG_CONST png_uint_32 display_mask[2][3][3] =
- {
- /* Little-endian byte masks for PACKSWAP */
- { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) },
- /* Normal (big-endian byte) masks - PNG format */
- { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) }
- };
-
-# define MASK(pass,depth,display,png)\
- ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\
- row_mask[png][DEPTH_INDEX(depth)][pass])
-
-#else /* !PNG_USE_COMPILE_TIME_MASKS */
- /* This is the runtime alternative: it seems unlikely that this will
- * ever be either smaller or faster than the compile time approach.
- */
-# define MASK(pass,depth,display,png)\
- ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png))
-#endif /* !PNG_USE_COMPILE_TIME_MASKS */
-
- /* Use the appropriate mask to copy the required bits. In some cases
- * the byte mask will be 0 or 0xff, optimize these cases. row_width is
- * the number of pixels, but the code copies bytes, so it is necessary
- * to special case the end.
- */
- png_uint_32 pixels_per_byte = 8 / pixel_depth;
- png_uint_32 mask;
-
-# ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (png_ptr->transformations & PNG_PACKSWAP)
- mask = MASK(pass, pixel_depth, display, 0);
-
- else
-# endif
- mask = MASK(pass, pixel_depth, display, 1);
-
- for (;;)
- {
- png_uint_32 m;
-
- /* It doesn't matter in the following if png_uint_32 has more than
- * 32 bits because the high bits always match those in m<<24; it is,
- * however, essential to use OR here, not +, because of this.
- */
- m = mask;
- mask = (m >> 8) | (m << 24); /* rotate right to good compilers */
- m &= 0xff;
-
- if (m != 0) /* something to copy */
- {
- if (m != 0xff)
- *dp = (png_byte)((*dp & ~m) | (*sp & m));
- else
- *dp = *sp;
- }
-
- /* NOTE: this may overwrite the last byte with garbage if the image
- * is not an exact number of bytes wide; libpng has always done
- * this.
- */
- if (row_width <= pixels_per_byte)
- break; /* May need to restore part of the last byte */
-
- row_width -= pixels_per_byte;
- ++dp;
- ++sp;
- }
- }
-
- else /* pixel_depth >= 8 */
- {
- unsigned int bytes_to_copy, bytes_to_jump;
-
- /* Validate the depth - it must be a multiple of 8 */
- if (pixel_depth & 7)
- png_error(png_ptr, "invalid user transform pixel depth");
-
- pixel_depth >>= 3; /* now in bytes */
- row_width *= pixel_depth;
-
- /* Regardless of pass number the Adam 7 interlace always results in a
- * fixed number of pixels to copy then to skip. There may be a
- * different number of pixels to skip at the start though.
- */
- {
- unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
-
- row_width -= offset;
- dp += offset;
- sp += offset;
- }
-
- /* Work out the bytes to copy. */
- if (display)
- {
- /* When doing the 'block' algorithm the pixel in the pass gets
- * replicated to adjacent pixels. This is why the even (0,2,4,6)
- * passes are skipped above - the entire expanded row is copied.
- */
- bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth;
-
- /* But don't allow this number to exceed the actual row width. */
- if (bytes_to_copy > row_width)
- bytes_to_copy = row_width;
- }
-
- else /* normal row; Adam7 only ever gives us one pixel to copy. */
- bytes_to_copy = pixel_depth;
-
- /* In Adam7 there is a constant offset between where the pixels go. */
- bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth;
-
- /* And simply copy these bytes. Some optimization is possible here,
- * depending on the value of 'bytes_to_copy'. Special case the low
- * byte counts, which we know to be frequent.
- *
- * Notice that these cases all 'return' rather than 'break' - this
- * avoids an unnecessary test on whether to restore the last byte
- * below.
- */
- switch (bytes_to_copy)
- {
- case 1:
- for (;;)
- {
- *dp = *sp;
-
- if (row_width <= bytes_to_jump)
- return;
-
- dp += bytes_to_jump;
- sp += bytes_to_jump;
- row_width -= bytes_to_jump;
- }
-
- case 2:
- /* There is a possibility of a partial copy at the end here; this
- * slows the code down somewhat.
- */
- do
- {
- dp[0] = sp[0], dp[1] = sp[1];
-
- if (row_width <= bytes_to_jump)
- return;
-
- sp += bytes_to_jump;
- dp += bytes_to_jump;
- row_width -= bytes_to_jump;
- }
- while (row_width > 1);
-
- /* And there can only be one byte left at this point: */
- *dp = *sp;
- return;
-
- case 3:
- /* This can only be the RGB case, so each copy is exactly one
- * pixel and it is not necessary to check for a partial copy.
- */
- for(;;)
- {
- dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2];
-
- if (row_width <= bytes_to_jump)
- return;
-
- sp += bytes_to_jump;
- dp += bytes_to_jump;
- row_width -= bytes_to_jump;
- }
-
- default:
-#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE
- /* Check for double byte alignment and, if possible, use a
- * 16-bit copy. Don't attempt this for narrow images - ones that
- * are less than an interlace panel wide. Don't attempt it for
- * wide bytes_to_copy either - use the memcpy there.
- */
- if (bytes_to_copy < 16 /*else use memcpy*/ &&
- png_isaligned(dp, png_uint_16) &&
- png_isaligned(sp, png_uint_16) &&
- bytes_to_copy % (sizeof (png_uint_16)) == 0 &&
- bytes_to_jump % (sizeof (png_uint_16)) == 0)
- {
- /* Everything is aligned for png_uint_16 copies, but try for
- * png_uint_32 first.
- */
- if (png_isaligned(dp, png_uint_32) &&
- png_isaligned(sp, png_uint_32) &&
- bytes_to_copy % (sizeof (png_uint_32)) == 0 &&
- bytes_to_jump % (sizeof (png_uint_32)) == 0)
- {
- png_uint_32p dp32 = png_aligncast(png_uint_32p,dp);
- png_const_uint_32p sp32 = png_aligncastconst(
- png_const_uint_32p, sp);
- size_t skip = (bytes_to_jump-bytes_to_copy) /
- (sizeof (png_uint_32));
-
- do
- {
- size_t c = bytes_to_copy;
- do
- {
- *dp32++ = *sp32++;
- c -= (sizeof (png_uint_32));
- }
- while (c > 0);
-
- if (row_width <= bytes_to_jump)
- return;
-
- dp32 += skip;
- sp32 += skip;
- row_width -= bytes_to_jump;
- }
- while (bytes_to_copy <= row_width);
-
- /* Get to here when the row_width truncates the final copy.
- * There will be 1-3 bytes left to copy, so don't try the
- * 16-bit loop below.
- */
- dp = (png_bytep)dp32;
- sp = (png_const_bytep)sp32;
- do
- *dp++ = *sp++;
- while (--row_width > 0);
- return;
- }
-
- /* Else do it in 16-bit quantities, but only if the size is
- * not too large.
- */
- else
- {
- png_uint_16p dp16 = png_aligncast(png_uint_16p, dp);
- png_const_uint_16p sp16 = png_aligncastconst(
- png_const_uint_16p, sp);
- size_t skip = (bytes_to_jump-bytes_to_copy) /
- (sizeof (png_uint_16));
-
- do
- {
- size_t c = bytes_to_copy;
- do
- {
- *dp16++ = *sp16++;
- c -= (sizeof (png_uint_16));
- }
- while (c > 0);
-
- if (row_width <= bytes_to_jump)
- return;
-
- dp16 += skip;
- sp16 += skip;
- row_width -= bytes_to_jump;
- }
- while (bytes_to_copy <= row_width);
-
- /* End of row - 1 byte left, bytes_to_copy > row_width: */
- dp = (png_bytep)dp16;
- sp = (png_const_bytep)sp16;
- do
- *dp++ = *sp++;
- while (--row_width > 0);
- return;
- }
- }
-#endif /* PNG_ALIGN_ code */
-
- /* The true default - use a memcpy: */
- for (;;)
- {
- memcpy(dp, sp, bytes_to_copy);
-
- if (row_width <= bytes_to_jump)
- return;
-
- sp += bytes_to_jump;
- dp += bytes_to_jump;
- row_width -= bytes_to_jump;
- if (bytes_to_copy > row_width)
- bytes_to_copy = row_width;
- }
- }
-
- /* NOT REACHED*/
- } /* pixel_depth >= 8 */
-
- /* Here if pixel_depth < 8 to check 'end_ptr' below. */
- }
- else
-#endif
-
- /* If here then the switch above wasn't used so just memcpy the whole row
- * from the temporary row buffer (notice that this overwrites the end of the
- * destination row if it is a partial byte.)
- */
- memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
-
- /* Restore the overwritten bits from the last byte if necessary. */
- if (end_ptr != NULL)
- *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask));
-}
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
-void /* PRIVATE */
-png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
- png_uint_32 transformations /* Because these may affect the byte layout */)
-{
- /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
- /* Offset to next interlace block */
- static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
-
- png_debug(1, "in png_do_read_interlace");
- if (row != NULL && row_info != NULL)
- {
- png_uint_32 final_width;
-
- final_width = row_info->width * png_pass_inc[pass];
-
- switch (row_info->pixel_depth)
- {
- case 1:
- {
- png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
- png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
- int sshift, dshift;
- int s_start, s_end, s_inc;
- int jstop = png_pass_inc[pass];
- png_byte v;
- png_uint_32 i;
- int j;
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (transformations & PNG_PACKSWAP)
- {
- sshift = (int)((row_info->width + 7) & 0x07);
- dshift = (int)((final_width + 7) & 0x07);
- s_start = 7;
- s_end = 0;
- s_inc = -1;
- }
-
- else
-#endif
- {
- sshift = 7 - (int)((row_info->width + 7) & 0x07);
- dshift = 7 - (int)((final_width + 7) & 0x07);
- s_start = 0;
- s_end = 7;
- s_inc = 1;
- }
-
- for (i = 0; i < row_info->width; i++)
- {
- v = (png_byte)((*sp >> sshift) & 0x01);
- for (j = 0; j < jstop; j++)
- {
- unsigned int tmp = *dp & (0x7f7f >> (7 - dshift));
- tmp |= v << dshift;
- *dp = (png_byte)(tmp & 0xff);
-
- if (dshift == s_end)
- {
- dshift = s_start;
- dp--;
- }
-
- else
- dshift += s_inc;
- }
-
- if (sshift == s_end)
- {
- sshift = s_start;
- sp--;
- }
-
- else
- sshift += s_inc;
- }
- break;
- }
-
- case 2:
- {
- png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
- png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
- int sshift, dshift;
- int s_start, s_end, s_inc;
- int jstop = png_pass_inc[pass];
- png_uint_32 i;
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (transformations & PNG_PACKSWAP)
- {
- sshift = (int)(((row_info->width + 3) & 0x03) << 1);
- dshift = (int)(((final_width + 3) & 0x03) << 1);
- s_start = 6;
- s_end = 0;
- s_inc = -2;
- }
-
- else
-#endif
- {
- sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
- dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
- s_start = 0;
- s_end = 6;
- s_inc = 2;
- }
-
- for (i = 0; i < row_info->width; i++)
- {
- png_byte v;
- int j;
-
- v = (png_byte)((*sp >> sshift) & 0x03);
- for (j = 0; j < jstop; j++)
- {
- unsigned int tmp = *dp & (0x3f3f >> (6 - dshift));
- tmp |= v << dshift;
- *dp = (png_byte)(tmp & 0xff);
-
- if (dshift == s_end)
- {
- dshift = s_start;
- dp--;
- }
-
- else
- dshift += s_inc;
- }
-
- if (sshift == s_end)
- {
- sshift = s_start;
- sp--;
- }
-
- else
- sshift += s_inc;
- }
- break;
- }
-
- case 4:
- {
- png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
- png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
- int sshift, dshift;
- int s_start, s_end, s_inc;
- png_uint_32 i;
- int jstop = png_pass_inc[pass];
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (transformations & PNG_PACKSWAP)
- {
- sshift = (int)(((row_info->width + 1) & 0x01) << 2);
- dshift = (int)(((final_width + 1) & 0x01) << 2);
- s_start = 4;
- s_end = 0;
- s_inc = -4;
- }
-
- else
-#endif
- {
- sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
- dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
- s_start = 0;
- s_end = 4;
- s_inc = 4;
- }
-
- for (i = 0; i < row_info->width; i++)
- {
- png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
- int j;
-
- for (j = 0; j < jstop; j++)
- {
- unsigned int tmp = *dp & (0xf0f >> (4 - dshift));
- tmp |= v << dshift;
- *dp = (png_byte)(tmp & 0xff);
-
- if (dshift == s_end)
- {
- dshift = s_start;
- dp--;
- }
-
- else
- dshift += s_inc;
- }
-
- if (sshift == s_end)
- {
- sshift = s_start;
- sp--;
- }
-
- else
- sshift += s_inc;
- }
- break;
- }
-
- default:
- {
- png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
-
- png_bytep sp = row + (png_size_t)(row_info->width - 1)
- * pixel_bytes;
-
- png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
-
- int jstop = png_pass_inc[pass];
- png_uint_32 i;
-
- for (i = 0; i < row_info->width; i++)
- {
- png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */
- int j;
-
- memcpy(v, sp, pixel_bytes);
-
- for (j = 0; j < jstop; j++)
- {
- memcpy(dp, v, pixel_bytes);
- dp -= pixel_bytes;
- }
-
- sp -= pixel_bytes;
- }
- break;
- }
- }
-
- row_info->width = final_width;
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
- }
-#ifndef PNG_READ_PACKSWAP_SUPPORTED
- PNG_UNUSED(transformations) /* Silence compiler warning */
-#endif
-}
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-
-static void
-png_read_filter_row_sub(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- png_size_t i;
- png_size_t istop = row_info->rowbytes;
- unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
- png_bytep rp = row + bpp;
-
- PNG_UNUSED(prev_row)
-
- for (i = bpp; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
- rp++;
- }
-}
-
-static void
-png_read_filter_row_up(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- png_size_t i;
- png_size_t istop = row_info->rowbytes;
- png_bytep rp = row;
- png_const_bytep pp = prev_row;
-
- for (i = 0; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
- rp++;
- }
-}
-
-static void
-png_read_filter_row_avg(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- png_size_t i;
- png_bytep rp = row;
- png_const_bytep pp = prev_row;
- unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
- png_size_t istop = row_info->rowbytes - bpp;
-
- for (i = 0; i < bpp; i++)
- {
- *rp = (png_byte)(((int)(*rp) +
- ((int)(*pp++) / 2 )) & 0xff);
-
- rp++;
- }
-
- for (i = 0; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) +
- (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
-
- rp++;
- }
-}
-
-static void
-png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- png_bytep rp_end = row + row_info->rowbytes;
- int a, c;
-
- /* First pixel/byte */
- c = *prev_row++;
- a = *row + c;
- *row++ = (png_byte)a;
-
- /* Remainder */
- while (row < rp_end)
- {
- int b, pa, pb, pc, p;
-
- a &= 0xff; /* From previous iteration or start */
- b = *prev_row++;
-
- p = b - c;
- pc = a - c;
-
-# ifdef PNG_USE_ABS
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
-# else
- pa = p < 0 ? -p : p;
- pb = pc < 0 ? -pc : pc;
- pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-# endif
-
- /* Find the best predictor, the least of pa, pb, pc favoring the earlier
- * ones in the case of a tie.
- */
- if (pb < pa) pa = pb, a = b;
- if (pc < pa) a = c;
-
- /* Calculate the current pixel in a, and move the previous row pixel to c
- * for the next time round the loop
- */
- c = b;
- a += *row;
- *row++ = (png_byte)a;
- }
-}
-
-static void
-png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row)
-{
- int bpp = (row_info->pixel_depth + 7) >> 3;
- png_bytep rp_end = row + bpp;
-
- /* Process the first pixel in the row completely (this is the same as 'up'
- * because there is only one candidate predictor for the first row).
- */
- while (row < rp_end)
- {
- int a = *row + *prev_row++;
- *row++ = (png_byte)a;
- }
-
- /* Remainder */
- rp_end += row_info->rowbytes - bpp;
-
- while (row < rp_end)
- {
- int a, b, c, pa, pb, pc, p;
-
- c = *(prev_row - bpp);
- a = *(row - bpp);
- b = *prev_row++;
-
- p = b - c;
- pc = a - c;
-
-# ifdef PNG_USE_ABS
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
-# else
- pa = p < 0 ? -p : p;
- pb = pc < 0 ? -pc : pc;
- pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-# endif
-
- if (pb < pa) pa = pb, a = b;
- if (pc < pa) a = c;
-
- c = b;
- a += *row;
- *row++ = (png_byte)a;
- }
-}
-
-static void
-png_init_filter_functions(png_structrp pp)
- /* This function is called once for every PNG image to set the
- * implementations required to reverse the filtering of PNG rows. Reversing
- * the filter is the first transformation performed on the row data. It is
- * performed in place, therefore an implementation can be selected based on
- * the image pixel format. If the implementation depends on image width then
- * take care to ensure that it works correctly if the image is interlaced -
- * interlacing causes the actual row width to vary.
- */
-{
- unsigned int bpp = (pp->pixel_depth + 7) >> 3;
-
- pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub;
- pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up;
- pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg;
- if (bpp == 1)
- pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
- png_read_filter_row_paeth_1byte_pixel;
- else
- pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
- png_read_filter_row_paeth_multibyte_pixel;
-
-#ifdef PNG_FILTER_OPTIMIZATIONS
- /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to
- * call to install hardware optimizations for the above functions; simply
- * replace whatever elements of the pp->read_filter[] array with a hardware
- * specific (or, for that matter, generic) optimization.
- *
- * To see an example of this examine what configure.ac does when
- * --enable-arm-neon is specified on the command line.
- */
- PNG_FILTER_OPTIMIZATIONS(pp, bpp);
-#endif
-}
-
-void /* PRIVATE */
-png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row,
- png_const_bytep prev_row, int filter)
-{
- /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define
- * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic
- * implementations. See png_init_filter_functions above.
- */
- if (pp->read_filter[0] == NULL)
- png_init_filter_functions(pp);
- if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
- pp->read_filter[filter-1](row_info, row, prev_row);
-}
-
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-void /* PRIVATE */
-png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
- png_alloc_size_t avail_out)
-{
- /* Loop reading IDATs and decompressing the result into output[avail_out] */
- png_ptr->zstream.next_out = output;
- png_ptr->zstream.avail_out = 0; /* safety: set below */
-
- if (output == NULL)
- avail_out = 0;
-
- do
- {
- int ret;
- png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
-
- if (png_ptr->zstream.avail_in == 0)
- {
- uInt avail_in;
- png_bytep buffer;
-
- while (png_ptr->idat_size == 0)
- {
- png_crc_finish(png_ptr, 0);
-
- png_ptr->idat_size = png_read_chunk_header(png_ptr);
- /* This is an error even in the 'check' case because the code just
- * consumed a non-IDAT header.
- */
- if (png_ptr->chunk_name != png_IDAT)
- png_error(png_ptr, "Not enough image data");
- }
-
- avail_in = png_ptr->IDAT_read_size;
-
- if (avail_in > png_ptr->idat_size)
- avail_in = (uInt)png_ptr->idat_size;
-
- /* A PNG with a gradually increasing IDAT size will defeat this attempt
- * to minimize memory usage by causing lots of re-allocs, but
- * realistically doing IDAT_read_size re-allocs is not likely to be a
- * big problem.
- */
- buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/);
-
- png_crc_read(png_ptr, buffer, avail_in);
- png_ptr->idat_size -= avail_in;
-
- png_ptr->zstream.next_in = buffer;
- png_ptr->zstream.avail_in = avail_in;
- }
-
- /* And set up the output side. */
- if (output != NULL) /* standard read */
- {
- uInt out = ZLIB_IO_MAX;
-
- if (out > avail_out)
- out = (uInt)avail_out;
-
- avail_out -= out;
- png_ptr->zstream.avail_out = out;
- }
-
- else /* after last row, checking for end */
- {
- png_ptr->zstream.next_out = tmpbuf;
- png_ptr->zstream.avail_out = (sizeof tmpbuf);
- }
-
- /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the
- * process. If the LZ stream is truncated the sequential reader will
- * terminally damage the stream, above, by reading the chunk header of the
- * following chunk (it then exits with png_error).
- *
- * TODO: deal more elegantly with truncated IDAT lists.
- */
- ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
-
- /* Take the unconsumed output back. */
- if (output != NULL)
- avail_out += png_ptr->zstream.avail_out;
-
- else /* avail_out counts the extra bytes */
- avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out;
-
- png_ptr->zstream.avail_out = 0;
-
- if (ret == Z_STREAM_END)
- {
- /* Do this for safety; we won't read any more into this row. */
- png_ptr->zstream.next_out = NULL;
-
- png_ptr->mode |= PNG_AFTER_IDAT;
- png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
-
- if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0)
- png_chunk_benign_error(png_ptr, "Extra compressed data");
- break;
- }
-
- if (ret != Z_OK)
- {
- png_zstream_error(png_ptr, ret);
-
- if (output != NULL)
- png_chunk_error(png_ptr, png_ptr->zstream.msg);
-
- else /* checking */
- {
- png_chunk_benign_error(png_ptr, png_ptr->zstream.msg);
- return;
- }
- }
- } while (avail_out > 0);
-
- if (avail_out > 0)
- {
- /* The stream ended before the image; this is the same as too few IDATs so
- * should be handled the same way.
- */
- if (output != NULL)
- png_error(png_ptr, "Not enough image data");
-
- else /* the deflate stream contained extra data */
- png_chunk_benign_error(png_ptr, "Too much image data");
- }
-}
-
-void /* PRIVATE */
-png_read_finish_IDAT(png_structrp png_ptr)
-{
- /* We don't need any more data and the stream should have ended, however the
- * LZ end code may actually not have been processed. In this case we must
- * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk
- * may still remain to be consumed.
- */
- if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
- {
- /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in
- * the compressed stream, but the stream may be damaged too, so even after
- * this call we may need to terminate the zstream ownership.
- */
- png_read_IDAT_data(png_ptr, NULL, 0);
- png_ptr->zstream.next_out = NULL; /* safety */
-
- /* Now clear everything out for safety; the following may not have been
- * done.
- */
- if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
- {
- png_ptr->mode |= PNG_AFTER_IDAT;
- png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
- }
- }
-
- /* If the zstream has not been released do it now *and* terminate the reading
- * of the final IDAT chunk.
- */
- if (png_ptr->zowner == png_IDAT)
- {
- /* Always do this; the pointers otherwise point into the read buffer. */
- png_ptr->zstream.next_in = NULL;
- png_ptr->zstream.avail_in = 0;
-
- /* Now we no longer own the zstream. */
- png_ptr->zowner = 0;
-
- /* The slightly weird semantics of the sequential IDAT reading is that we
- * are always in or at the end of an IDAT chunk, so we always need to do a
- * crc_finish here. If idat_size is non-zero we also need to read the
- * spurious bytes at the end of the chunk now.
- */
- (void)png_crc_finish(png_ptr, png_ptr->idat_size);
- }
-}
-
-void /* PRIVATE */
-png_read_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 */
- static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
-
- /* Offset to next interlace block */
- static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
-
- /* Start of interlace block in the y direction */
- static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
-
- /* Offset to next interlace block in the y direction */
- static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-
- png_debug(1, "in png_read_finish_row");
- png_ptr->row_number++;
- if (png_ptr->row_number < png_ptr->num_rows)
- return;
-
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- if (png_ptr->interlaced)
- {
- png_ptr->row_number = 0;
-
- /* TO DO: don't do this if prev_row isn't needed (requires
- * read-ahead of the next row's filter byte.
- */
- memset(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];
-
- 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];
- }
-
- else /* if (png_ptr->transformations & PNG_INTERLACE) */
- break; /* libpng deinterlacing sees every row */
-
- } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
-
- if (png_ptr->pass < 7)
- return;
- }
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-
- /* Here after at the end of the last row of the last pass. */
- png_read_finish_IDAT(png_ptr);
-}
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
-
-void /* PRIVATE */
-png_read_start_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 */
- static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
-
- /* Offset to next interlace block */
- static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
-
- /* Start of interlace block in the y direction */
- static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
-
- /* Offset to next interlace block in the y direction */
- static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
-#endif
-
- int max_pixel_depth;
- png_size_t row_bytes;
-
- png_debug(1, "in png_read_start_row");
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
- png_init_read_transformations(png_ptr);
-#endif
-#ifdef PNG_READ_INTERLACING_SUPPORTED
- if (png_ptr->interlaced)
- {
- if (!(png_ptr->transformations & PNG_INTERLACE))
- png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
- png_pass_ystart[0]) / png_pass_yinc[0];
-
- else
- png_ptr->num_rows = png_ptr->height;
-
- 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];
- }
-
- else
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
- {
- png_ptr->num_rows = png_ptr->height;
- png_ptr->iwidth = png_ptr->width;
- }
-
- max_pixel_depth = png_ptr->pixel_depth;
-
- /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of
- * calculations to calculate the final pixel depth, then
- * png_do_read_transforms actually does the transforms. This means that the
- * code which effectively calculates this value is actually repeated in three
- * separate places. They must all match. Innocent changes to the order of
- * transformations can and will break libpng in a way that causes memory
- * overwrites.
- *
- * TODO: fix this.
- */
-#ifdef PNG_READ_PACK_SUPPORTED
- if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
- max_pixel_depth = 8;
-#endif
-
-#ifdef PNG_READ_EXPAND_SUPPORTED
- if (png_ptr->transformations & PNG_EXPAND)
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (png_ptr->num_trans)
- max_pixel_depth = 32;
-
- else
- max_pixel_depth = 24;
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
- {
- if (max_pixel_depth < 8)
- max_pixel_depth = 8;
-
- if (png_ptr->num_trans)
- max_pixel_depth *= 2;
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
- {
- if (png_ptr->num_trans)
- {
- max_pixel_depth *= 4;
- max_pixel_depth /= 3;
- }
- }
- }
-#endif
-
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
- if (png_ptr->transformations & PNG_EXPAND_16)
- {
-# ifdef PNG_READ_EXPAND_SUPPORTED
- /* In fact it is an error if it isn't supported, but checking is
- * the safe way.
- */
- if (png_ptr->transformations & PNG_EXPAND)
- {
- if (png_ptr->bit_depth < 16)
- max_pixel_depth *= 2;
- }
- else
-# endif
- png_ptr->transformations &= ~PNG_EXPAND_16;
- }
-#endif
-
-#ifdef PNG_READ_FILLER_SUPPORTED
- if (png_ptr->transformations & (PNG_FILLER))
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
- {
- if (max_pixel_depth <= 8)
- max_pixel_depth = 16;
-
- else
- max_pixel_depth = 32;
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB ||
- png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (max_pixel_depth <= 32)
- max_pixel_depth = 32;
-
- else
- max_pixel_depth = 64;
- }
- }
-#endif
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
- if (png_ptr->transformations & PNG_GRAY_TO_RGB)
- {
- if (
-#ifdef PNG_READ_EXPAND_SUPPORTED
- (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
-#endif
-#ifdef PNG_READ_FILLER_SUPPORTED
- (png_ptr->transformations & (PNG_FILLER)) ||
-#endif
- png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- if (max_pixel_depth <= 16)
- max_pixel_depth = 32;
-
- else
- max_pixel_depth = 64;
- }
-
- else
- {
- if (max_pixel_depth <= 8)
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- max_pixel_depth = 32;
-
- else
- max_pixel_depth = 24;
- }
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- max_pixel_depth = 64;
-
- else
- max_pixel_depth = 48;
- }
- }
-#endif
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
-defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
- if (png_ptr->transformations & PNG_USER_TRANSFORM)
- {
- int user_pixel_depth = png_ptr->user_transform_depth *
- png_ptr->user_transform_channels;
-
- if (user_pixel_depth > max_pixel_depth)
- max_pixel_depth = user_pixel_depth;
- }
-#endif
-
- /* This value is stored in png_struct and double checked in the row read
- * code.
- */
- png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
- png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
-
- /* Align the width on the next larger 8 pixels. Mainly used
- * for interlacing
- */
- row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
- /* Calculate the maximum bytes needed, adding a byte and a pixel
- * for safety's sake
- */
- row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
- 1 + ((max_pixel_depth + 7) >> 3);
-
-#ifdef PNG_MAX_MALLOC_64K
- if (row_bytes > (png_uint_32)65536L)
- png_error(png_ptr, "This image requires a row greater than 64KB");
-#endif
-
- if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
- {
- png_free(png_ptr, png_ptr->big_row_buf);
- png_free(png_ptr, png_ptr->big_prev_row);
-
- if (png_ptr->interlaced)
- png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
- row_bytes + 48);
-
- else
- png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
-
- png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
-
-#ifdef PNG_ALIGNED_MEMORY_SUPPORTED
- /* Use 16-byte aligned memory for row_buf with at least 16 bytes
- * of padding before and after row_buf; treat prev_row similarly.
- * NOTE: the alignment is to the start of the pixels, one beyond the start
- * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this
- * was incorrect; the filter byte was aligned, which had the exact
- * opposite effect of that intended.
- */
- {
- png_bytep temp = png_ptr->big_row_buf + 32;
- int extra = (int)((temp - (png_bytep)0) & 0x0f);
- png_ptr->row_buf = temp - extra - 1/*filter byte*/;
-
- temp = png_ptr->big_prev_row + 32;
- extra = (int)((temp - (png_bytep)0) & 0x0f);
- png_ptr->prev_row = temp - extra - 1/*filter byte*/;
- }
-
-#else
- /* Use 31 bytes of padding before and 17 bytes after row_buf. */
- png_ptr->row_buf = png_ptr->big_row_buf + 31;
- png_ptr->prev_row = png_ptr->big_prev_row + 31;
-#endif
- png_ptr->old_big_row_buf_size = row_bytes + 48;
- }
-
-#ifdef PNG_MAX_MALLOC_64K
- if (png_ptr->rowbytes > 65535)
- png_error(png_ptr, "This image requires a row greater than 64KB");
-
-#endif
- if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
- png_error(png_ptr, "Row has too many bytes to allocate in memory");
-
- memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
-
- png_debug1(3, "width = %u,", png_ptr->width);
- png_debug1(3, "height = %u,", png_ptr->height);
- png_debug1(3, "iwidth = %u,", png_ptr->iwidth);
- png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
- png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
- png_debug1(3, "irowbytes = %lu",
- (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
-
- /* The sequential reader needs a buffer for IDAT, but the progressive reader
- * does not, so free the read buffer now regardless; the sequential reader
- * reallocates it on demand.
- */
- if (png_ptr->read_buffer)
- {
- png_bytep buffer = png_ptr->read_buffer;
-
- png_ptr->read_buffer_size = 0;
- png_ptr->read_buffer = NULL;
- png_free(png_ptr, buffer);
- }
-
- /* Finally claim the zstream for the inflate of the IDAT data, use the bits
- * value from the stream (note that this will result in a fatal error if the
- * IDAT stream has a bogus deflate header window_bits value, but this should
- * not be happening any longer!)
- */
- if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK)
- png_error(png_ptr, png_ptr->zstream.msg);
-
- png_ptr->flags |= PNG_FLAG_ROW_INIT;
-}
-#endif /* PNG_READ_SUPPORTED */
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