diff options
Diffstat (limited to 'plugins/FreeImage/Source/LibPNG/pngrutil.c')
| -rw-r--r-- | plugins/FreeImage/Source/LibPNG/pngrutil.c | 3666 |
1 files changed, 3666 insertions, 0 deletions
diff --git a/plugins/FreeImage/Source/LibPNG/pngrutil.c b/plugins/FreeImage/Source/LibPNG/pngrutil.c new file mode 100644 index 0000000000..3fe202063f --- /dev/null +++ b/plugins/FreeImage/Source/LibPNG/pngrutil.c @@ -0,0 +1,3666 @@ +
+/* pngrutil.c - utilities to read a PNG file
+ *
+ * Last changed in libpng 1.5.4 [July 7, 2011]
+ * Copyright (c) 1998-2011 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
+
+#define png_strtod(p,a,b) strtod(a,b)
+
+png_uint_32 PNGAPI
+png_get_uint_31(png_structp 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_structp 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 & 0x80000000L) == 0) /* non-negative */
+ return uval;
+
+ uval = (uval ^ 0xffffffffL) + 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_structp png_ptr, png_infop info_ptr)
+{
+ png_size_t num_checked, num_to_check;
+
+ /* Exit if the user application does not expect a signature. */
+ if (png_ptr->sig_bytes >= 8)
+ return;
+
+ num_checked = png_ptr->sig_bytes;
+ num_to_check = 8 - num_checked;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
+#endif
+
+ /* The signature must be serialized in a single I/O call. */
+ png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
+ png_ptr->sig_bytes = 8;
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+ png_error(png_ptr, "Not a PNG file");
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ if (num_checked < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
+/* Read the chunk header (length + type name).
+ * Put the type name into png_ptr->chunk_name, and return the length.
+ */
+png_uint_32 /* PRIVATE */
+png_read_chunk_header(png_structp 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_memcpy(png_ptr->chunk_name, buf + 4, 4);
+
+ png_debug2(0, "Reading %s chunk, length = %u",
+ png_ptr->chunk_name, length);
+
+ /* Reset the crc and run it over the chunk name. */
+ png_reset_crc(png_ptr);
+ png_calculate_crc(png_ptr, png_ptr->chunk_name, 4);
+
+ /* Check to see if chunk name is valid. */
+ 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_structp png_ptr, png_bytep buf, png_size_t 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 a 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_structp png_ptr, png_uint_32 skip)
+{
+ png_size_t i;
+ png_size_t istop = png_ptr->zbuf_size;
+
+ for (i = (png_size_t)skip; i > istop; i -= istop)
+ {
+ png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
+ }
+
+ if (i)
+ {
+ png_crc_read(png_ptr, png_ptr->zbuf, i);
+ }
+
+ if (png_crc_error(png_ptr))
+ {
+ if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */
+ !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
+ (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */
+ (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_structp png_ptr)
+{
+ png_byte crc_bytes[4];
+ png_uint_32 crc;
+ int need_crc = 1;
+
+ if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
+ {
+ 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);
+}
+
+#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
+static png_size_t
+png_inflate(png_structp png_ptr, png_bytep data, png_size_t size,
+ png_bytep output, png_size_t output_size)
+{
+ png_size_t count = 0;
+
+ /* 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 forces access of the input data to be separated from
+ * at least some of the use by some period of time.
+ */
+ png_ptr->zstream.next_in = data;
+ /* avail_in is set below from 'size' */
+ png_ptr->zstream.avail_in = 0;
+
+ while (1)
+ {
+ int ret, avail;
+
+ /* 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 o
+ * 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.
+ */
+ if (png_ptr->zstream.avail_in == 0 && size > 0)
+ {
+ if (size <= ZLIB_IO_MAX)
+ {
+ /* The value is less than ZLIB_IO_MAX so the cast is safe: */
+ png_ptr->zstream.avail_in = (uInt)size;
+ size = 0;
+ }
+
+ else
+ {
+ png_ptr->zstream.avail_in = ZLIB_IO_MAX;
+ size -= ZLIB_IO_MAX;
+ }
+ }
+
+ /* Reset the output buffer each time round - we empty it
+ * after every inflate call.
+ */
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = png_ptr->zbuf_size;
+
+ ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
+ avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+
+ /* First copy/count any new output - but only if we didn't
+ * get an error code.
+ */
+ if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0)
+ {
+ png_size_t space = avail; /* > 0, see above */
+
+ if (output != 0 && output_size > count)
+ {
+ png_size_t copy = output_size - count;
+
+ if (space < copy)
+ copy = space;
+
+ png_memcpy(output + count, png_ptr->zbuf, copy);
+ }
+ count += space;
+ }
+
+ if (ret == Z_OK)
+ continue;
+
+ /* Termination conditions - always reset the zstream, it
+ * must be left in inflateInit state.
+ */
+ png_ptr->zstream.avail_in = 0;
+ inflateReset(&png_ptr->zstream);
+
+ if (ret == Z_STREAM_END)
+ return count; /* NOTE: may be zero. */
+
+ /* Now handle the error codes - the API always returns 0
+ * and the error message is dumped into the uncompressed
+ * buffer if available.
+ */
+# ifdef PNG_WARNINGS_SUPPORTED
+ {
+ png_const_charp msg;
+
+ if (png_ptr->zstream.msg != 0)
+ msg = png_ptr->zstream.msg;
+
+ else switch (ret)
+ {
+ case Z_BUF_ERROR:
+ msg = "Buffer error in compressed datastream";
+ break;
+
+ case Z_DATA_ERROR:
+ msg = "Data error in compressed datastream";
+ break;
+
+ default:
+ msg = "Incomplete compressed datastream";
+ break;
+ }
+
+ png_chunk_warning(png_ptr, msg);
+ }
+# endif
+
+ /* 0 means an error - notice that this code simply ignores
+ * zero length compressed chunks as a result.
+ */
+ return 0;
+ }
+}
+
+/*
+ * Decompress trailing data in a chunk. The assumption is that chunkdata
+ * 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).
+ */
+void /* PRIVATE */
+png_decompress_chunk(png_structp png_ptr, int comp_type,
+ png_size_t chunklength,
+ png_size_t prefix_size, png_size_t *newlength)
+{
+ /* The caller should guarantee this */
+ if (prefix_size > chunklength)
+ {
+ /* The recovery is to delete the chunk. */
+ png_warning(png_ptr, "invalid chunklength");
+ prefix_size = 0; /* To delete everything */
+ }
+
+ else if (comp_type == PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_size_t expanded_size = png_inflate(png_ptr,
+ (png_bytep)(png_ptr->chunkdata + prefix_size),
+ chunklength - prefix_size,
+ 0, /* output */
+ 0); /* output size */
+
+ /* Now check the limits on this chunk - if the limit fails the
+ * compressed data will be removed, the prefix will remain.
+ */
+#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+ if (png_ptr->user_chunk_malloc_max &&
+ (prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1))
+#else
+# ifdef PNG_USER_CHUNK_MALLOC_MAX
+ if ((PNG_USER_CHUNK_MALLOC_MAX > 0) &&
+ prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1)
+# endif
+#endif
+ png_warning(png_ptr, "Exceeded size limit while expanding chunk");
+
+ /* If the size is zero either there was an error and a message
+ * has already been output (warning) or the size really is zero
+ * and we have nothing to do - the code will exit through the
+ * error case below.
+ */
+#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \
+ defined(PNG_USER_CHUNK_MALLOC_MAX)
+ else if (expanded_size > 0)
+#else
+ if (expanded_size > 0)
+#endif
+ {
+ /* Success (maybe) - really uncompress the chunk. */
+ png_size_t new_size = 0;
+ png_charp text = png_malloc_warn(png_ptr,
+ prefix_size + expanded_size + 1);
+
+ if (text != NULL)
+ {
+ png_memcpy(text, png_ptr->chunkdata, prefix_size);
+ new_size = png_inflate(png_ptr,
+ (png_bytep)(png_ptr->chunkdata + prefix_size),
+ chunklength - prefix_size,
+ (png_bytep)(text + prefix_size), expanded_size);
+ text[prefix_size + expanded_size] = 0; /* just in case */
+
+ if (new_size == expanded_size)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = text;
+ *newlength = prefix_size + expanded_size;
+ return; /* The success return! */
+ }
+
+ png_warning(png_ptr, "png_inflate logic error");
+ png_free(png_ptr, text);
+ }
+
+ else
+ png_warning(png_ptr, "Not enough memory to decompress chunk");
+ }
+ }
+
+ else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
+ {
+ PNG_WARNING_PARAMETERS(p)
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type);
+ png_formatted_warning(png_ptr, p, "Unknown zTXt compression type @1");
+
+ /* The recovery is to simply drop the data. */
+ }
+
+ /* Generic error return - leave the prefix, delete the compressed
+ * data, reallocate the chunkdata to remove the potentially large
+ * amount of compressed data.
+ */
+ {
+ png_charp text = png_malloc_warn(png_ptr, prefix_size + 1);
+
+ if (text != NULL)
+ {
+ if (prefix_size > 0)
+ png_memcpy(text, png_ptr->chunkdata, prefix_size);
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = text;
+
+ /* This is an extra zero in the 'uncompressed' part. */
+ *(png_ptr->chunkdata + prefix_size) = 0x00;
+ }
+ /* Ignore a malloc error here - it is safe. */
+ }
+
+ *newlength = prefix_size;
+}
+#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
+
+/* Read and check the IDHR chunk */
+void /* PRIVATE */
+png_handle_IHDR(png_structp png_ptr, png_infop 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_error(png_ptr, "Out of place IHDR");
+
+ /* Check the length */
+ if (length != 13)
+ png_error(png_ptr, "Invalid IHDR chunk");
+
+ 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_structp png_ptr, png_infop 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_error(png_ptr, "Missing IHDR before PLTE");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid PLTE after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ png_error(png_ptr, "Duplicate PLTE chunk");
+
+ png_ptr->mode |= PNG_HAVE_PLTE;
+
+ if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
+ {
+ png_warning(png_ptr,
+ "Ignoring PLTE chunk in grayscale PNG");
+ png_crc_finish(png_ptr, length);
+ 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)
+ {
+ if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ png_warning(png_ptr, "Invalid palette chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else
+ {
+ png_error(png_ptr, "Invalid palette chunk");
+ }
+ }
+
+ 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).
+ */
+ 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
+
+ png_set_PLTE(png_ptr, info_ptr, palette, num);
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+ {
+ if (png_ptr->num_trans > (png_uint_16)num)
+ {
+ png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
+ png_ptr->num_trans = (png_uint_16)num;
+ }
+
+ if (info_ptr->num_trans > (png_uint_16)num)
+ {
+ png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
+ info_ptr->num_trans = (png_uint_16)num;
+ }
+ }
+ }
+#endif
+
+}
+
+void /* PRIVATE */
+png_handle_IEND(png_structp png_ptr, png_infop 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_error(png_ptr, "No image in file");
+ }
+
+ png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
+
+ if (length != 0)
+ {
+ png_warning(png_ptr, "Incorrect IEND chunk length");
+ }
+
+ png_crc_finish(png_ptr, length);
+
+ PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
+}
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+void /* PRIVATE */
+png_handle_gAMA(png_structp png_ptr, png_infop 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_error(png_ptr, "Missing IHDR before gAMA");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid gAMA after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place gAMA chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+#ifdef PNG_READ_sRGB_SUPPORTED
+ && !(info_ptr->valid & PNG_INFO_sRGB)
+#endif
+ )
+ {
+ png_warning(png_ptr, "Duplicate gAMA chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 4)
+ {
+ png_warning(png_ptr, "Incorrect gAMA chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 4);
+
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ igamma = png_get_fixed_point(NULL, buf);
+
+ /* Check for zero gamma or an error. */
+ if (igamma <= 0)
+ {
+ png_warning(png_ptr,
+ "Ignoring gAMA chunk with out of range gamma");
+
+ return;
+ }
+
+# ifdef PNG_READ_sRGB_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+ {
+ if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
+ {
+ PNG_WARNING_PARAMETERS(p)
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, igamma);
+ png_formatted_warning(png_ptr, p,
+ "Ignoring incorrect gAMA value @1 when sRGB is also present");
+ return;
+ }
+ }
+# endif /* PNG_READ_sRGB_SUPPORTED */
+
+# ifdef PNG_READ_GAMMA_SUPPORTED
+ /* Gamma correction on read is supported. */
+ png_ptr->gamma = igamma;
+# endif
+ /* And set the 'info' structure members. */
+ png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
+}
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+void /* PRIVATE */
+png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_size_t 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_error(png_ptr, "Missing IHDR before sBIT");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sBIT after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ {
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place sBIT chunk");
+ }
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
+ {
+ png_warning(png_ptr, "Duplicate sBIT chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ truelen = 3;
+
+ else
+ truelen = (png_size_t)png_ptr->channels;
+
+ if (length != truelen || length > 4)
+ {
+ png_warning(png_ptr, "Incorrect sBIT chunk length");
+ 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_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[32];
+ png_fixed_point x_white, y_white, x_red, y_red, x_green, y_green, x_blue,
+ y_blue;
+
+ png_debug(1, "in png_handle_cHRM");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before cHRM");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid cHRM after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Missing PLTE before cHRM");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
+# ifdef PNG_READ_sRGB_SUPPORTED
+ && !(info_ptr->valid & PNG_INFO_sRGB)
+# endif
+ )
+ {
+ png_warning(png_ptr, "Duplicate cHRM chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 32)
+ {
+ png_warning(png_ptr, "Incorrect cHRM chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 32);
+
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ x_white = png_get_fixed_point(NULL, buf);
+ y_white = png_get_fixed_point(NULL, buf + 4);
+ x_red = png_get_fixed_point(NULL, buf + 8);
+ y_red = png_get_fixed_point(NULL, buf + 12);
+ x_green = png_get_fixed_point(NULL, buf + 16);
+ y_green = png_get_fixed_point(NULL, buf + 20);
+ x_blue = png_get_fixed_point(NULL, buf + 24);
+ y_blue = png_get_fixed_point(NULL, buf + 28);
+
+ if (x_white == PNG_FIXED_ERROR ||
+ y_white == PNG_FIXED_ERROR ||
+ x_red == PNG_FIXED_ERROR ||
+ y_red == PNG_FIXED_ERROR ||
+ x_green == PNG_FIXED_ERROR ||
+ y_green == PNG_FIXED_ERROR ||
+ x_blue == PNG_FIXED_ERROR ||
+ y_blue == PNG_FIXED_ERROR)
+ {
+ png_warning(png_ptr, "Ignoring cHRM chunk with negative chromaticities");
+ return;
+ }
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+ if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
+ {
+ if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) ||
+ PNG_OUT_OF_RANGE(y_white, 32900, 1000) ||
+ PNG_OUT_OF_RANGE(x_red, 64000L, 1000) ||
+ PNG_OUT_OF_RANGE(y_red, 33000, 1000) ||
+ PNG_OUT_OF_RANGE(x_green, 30000, 1000) ||
+ PNG_OUT_OF_RANGE(y_green, 60000L, 1000) ||
+ PNG_OUT_OF_RANGE(x_blue, 15000, 1000) ||
+ PNG_OUT_OF_RANGE(y_blue, 6000, 1000))
+ {
+ PNG_WARNING_PARAMETERS(p)
+
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, x_white);
+ png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_fixed, y_white);
+ png_warning_parameter_signed(p, 3, PNG_NUMBER_FORMAT_fixed, x_red);
+ png_warning_parameter_signed(p, 4, PNG_NUMBER_FORMAT_fixed, y_red);
+ png_warning_parameter_signed(p, 5, PNG_NUMBER_FORMAT_fixed, x_green);
+ png_warning_parameter_signed(p, 6, PNG_NUMBER_FORMAT_fixed, y_green);
+ png_warning_parameter_signed(p, 7, PNG_NUMBER_FORMAT_fixed, x_blue);
+ png_warning_parameter_signed(p, 8, PNG_NUMBER_FORMAT_fixed, y_blue);
+
+ png_formatted_warning(png_ptr, p,
+ "Ignoring incorrect cHRM white(@1,@2) r(@3,@4)g(@5,@6)b(@7,@8) "
+ "when sRGB is also present");
+ }
+ return;
+ }
+#endif /* PNG_READ_sRGB_SUPPORTED */
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* Store the _white values as default coefficients for the rgb to gray
+ * operation if it is supported.
+ */
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
+ {
+ /* png_set_background has not been called, the coefficients must be in
+ * range for the following to work without overflow.
+ */
+ if (y_red <= (1<<17) && y_green <= (1<<17) && y_blue <= (1<<17))
+ {
+ /* The y values are chromaticities: Y/X+Y+Z, the weights for the gray
+ * transformation are simply the normalized Y values for red, green and
+ * blue scaled by 32768.
+ */
+ png_uint_32 w = y_red + y_green + y_blue;
+
+ png_ptr->rgb_to_gray_red_coeff = (png_uint_16)(((png_uint_32)y_red *
+ 32768)/w);
+ png_ptr->rgb_to_gray_green_coeff = (png_uint_16)(((png_uint_32)y_green
+ * 32768)/w);
+ png_ptr->rgb_to_gray_blue_coeff = (png_uint_16)(((png_uint_32)y_blue *
+ 32768)/w);
+ }
+ }
+#endif
+
+ png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red,
+ x_green, y_green, x_blue, y_blue);
+}
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+void /* PRIVATE */
+png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ int intent;
+ png_byte buf[1];
+
+ png_debug(1, "in png_handle_sRGB");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sRGB");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sRGB after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place sRGB chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+ {
+ png_warning(png_ptr, "Duplicate sRGB chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 1)
+ {
+ png_warning(png_ptr, "Incorrect sRGB chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 1);
+
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ intent = buf[0];
+
+ /* Check for bad intent */
+ if (intent >= PNG_sRGB_INTENT_LAST)
+ {
+ png_warning(png_ptr, "Unknown sRGB intent");
+ return;
+ }
+
+#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
+ {
+ if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500L, 500))
+ {
+ PNG_WARNING_PARAMETERS(p)
+
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed,
+ info_ptr->gamma);
+
+ png_formatted_warning(png_ptr, p,
+ "Ignoring incorrect gAMA value @1 when sRGB is also present");
+ }
+ }
+#endif /* PNG_READ_gAMA_SUPPORTED */
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+ if (PNG_OUT_OF_RANGE(info_ptr->x_white, 31270, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->y_white, 32900, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->x_red, 64000L, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->y_red, 33000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->x_green, 30000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->y_green, 60000L, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->x_blue, 15000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->y_blue, 6000, 1000))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect cHRM value when sRGB is also present");
+ }
+#endif /* PNG_READ_cHRM_SUPPORTED */
+
+ png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
+}
+#endif /* PNG_READ_sRGB_SUPPORTED */
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+void /* PRIVATE */
+png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+ png_byte compression_type;
+ png_bytep pC;
+ png_charp profile;
+ png_uint_32 skip = 0;
+ png_uint_32 profile_size;
+ png_alloc_size_t profile_length;
+ png_size_t slength, prefix_length, data_length;
+
+ png_debug(1, "in png_handle_iCCP");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before iCCP");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid iCCP after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place iCCP chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
+ {
+ png_warning(png_ptr, "Duplicate iCCP chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "iCCP chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (profile = png_ptr->chunkdata; *profile; profile++)
+ /* Empty loop to find end of name */ ;
+
+ ++profile;
+
+ /* There should be at least one zero (the compression type byte)
+ * following the separator, and we should be on it
+ */
+ if (profile >= png_ptr->chunkdata + slength - 1)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "Malformed iCCP chunk");
+ return;
+ }
+
+ /* Compression_type should always be zero */
+ compression_type = *profile++;
+
+ if (compression_type)
+ {
+ png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
+ compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8
+ wrote nonzero) */
+ }
+
+ prefix_length = profile - png_ptr->chunkdata;
+ png_decompress_chunk(png_ptr, compression_type,
+ slength, prefix_length, &data_length);
+
+ profile_length = data_length - prefix_length;
+
+ if (prefix_length > data_length || profile_length < 4)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "Profile size field missing from iCCP chunk");
+ return;
+ }
+
+ /* Check the profile_size recorded in the first 32 bits of the ICC profile */
+ pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
+ profile_size = ((*(pC )) << 24) |
+ ((*(pC + 1)) << 16) |
+ ((*(pC + 2)) << 8) |
+ ((*(pC + 3)) );
+
+ /* NOTE: the following guarantees that 'profile_length' fits into 32 bits,
+ * because profile_size is a 32 bit value.
+ */
+ if (profile_size < profile_length)
+ profile_length = profile_size;
+
+ /* And the following guarantees that profile_size == profile_length. */
+ if (profile_size > profile_length)
+ {
+ PNG_WARNING_PARAMETERS(p)
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+
+ png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_u, profile_size);
+ png_warning_parameter_unsigned(p, 2, PNG_NUMBER_FORMAT_u, profile_length);
+ png_formatted_warning(png_ptr, p,
+ "Ignoring iCCP chunk with declared size = @1 and actual length = @2");
+ return;
+ }
+
+ png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
+ compression_type, (png_bytep)png_ptr->chunkdata + prefix_length,
+ profile_size);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+}
+#endif /* PNG_READ_iCCP_SUPPORTED */
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+void /* PRIVATE */
+png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+ png_bytep entry_start;
+ png_sPLT_t new_palette;
+ png_sPLT_entryp pp;
+ png_uint_32 data_length;
+ int entry_size, i;
+ png_uint_32 skip = 0;
+ png_size_t slength;
+ 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_error(png_ptr, "Missing IHDR before sPLT");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sPLT after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "sPLT chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+
+ /* 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.
+ */
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (entry_start = (png_bytep)png_ptr->chunkdata; *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 > (png_bytep)png_ptr->chunkdata + slength - 2)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ 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 (and use 'length', not 'slength' here for clarity -
+ * they are guaranteed to be the same, see the tests above.)
+ */
+ data_length = length - (png_uint_32)(entry_start -
+ (png_bytep)png_ptr->chunkdata);
+
+ /* Integrity-check the data length */
+ if (data_length % entry_size)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "sPLT chunk has bad length");
+ return;
+ }
+
+ dl = (png_int_32)(data_length / entry_size);
+ max_dl = PNG_SIZE_MAX / png_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 * png_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_ptr->chunkdata;
+
+ png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, new_palette.entries);
+}
+#endif /* PNG_READ_sPLT_SUPPORTED */
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+void /* PRIVATE */
+png_handle_tRNS(png_structp png_ptr, png_infop 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_error(png_ptr, "Missing IHDR before tRNS");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid tRNS after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+ {
+ png_warning(png_ptr, "Duplicate tRNS chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_byte buf[2];
+
+ if (length != 2)
+ {
+ png_warning(png_ptr, "Incorrect tRNS chunk length");
+ png_crc_finish(png_ptr, length);
+ 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_warning(png_ptr, "Incorrect tRNS chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, (png_size_t)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))
+ {
+ /* Should be an error, but we can cope with it. */
+ png_warning(png_ptr, "Missing PLTE before tRNS");
+ }
+
+ if (length > (png_uint_32)png_ptr->num_palette ||
+ length > PNG_MAX_PALETTE_LENGTH)
+ {
+ png_warning(png_ptr, "Incorrect tRNS chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length == 0)
+ {
+ png_warning(png_ptr, "Zero length tRNS chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, readbuf, (png_size_t)length);
+ png_ptr->num_trans = (png_uint_16)length;
+ }
+
+ else
+ {
+ png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_ptr->num_trans = 0;
+ return;
+ }
+
+ 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_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_size_t truelen;
+ png_byte buf[6];
+ png_color_16 background;
+
+ png_debug(1, "in png_handle_bKGD");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before bKGD");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid bKGD after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ png_warning(png_ptr, "Missing PLTE before bKGD");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
+ {
+ png_warning(png_ptr, "Duplicate bKGD chunk");
+ png_crc_finish(png_ptr, length);
+ 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_warning(png_ptr, "Incorrect bKGD chunk length");
+ png_crc_finish(png_ptr, length);
+ 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_warning(png_ptr, "Incorrect bKGD chunk index value");
+ 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_structp png_ptr, png_infop 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_error(png_ptr, "Missing IHDR before hIST");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid hIST after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (!(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ png_warning(png_ptr, "Missing PLTE before hIST");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
+ {
+ png_warning(png_ptr, "Duplicate hIST chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ num = length / 2 ;
+
+ if (num != (unsigned int)png_ptr->num_palette || num >
+ (unsigned int)PNG_MAX_PALETTE_LENGTH)
+ {
+ png_warning(png_ptr, "Incorrect hIST chunk length");
+ png_crc_finish(png_ptr, length);
+ 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_structp png_ptr, png_infop 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_error(png_ptr, "Missing IHDR before pHYs");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid pHYs after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+ {
+ png_warning(png_ptr, "Duplicate pHYs chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 9)
+ {
+ png_warning(png_ptr, "Incorrect pHYs chunk length");
+ png_crc_finish(png_ptr, length);
+ 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_structp png_ptr, png_infop 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_error(png_ptr, "Missing IHDR before oFFs");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid oFFs after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+ {
+ png_warning(png_ptr, "Duplicate oFFs chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 9)
+ {
+ png_warning(png_ptr, "Incorrect oFFs chunk length");
+ png_crc_finish(png_ptr, length);
+ 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_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_int_32 X0, X1;
+ png_byte type, nparams;
+ png_charp buf, units, endptr;
+ png_charpp params;
+ png_size_t slength;
+ int i;
+
+ png_debug(1, "in png_handle_pCAL");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before pCAL");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid pCAL after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
+ {
+ png_warning(png_ptr, "Duplicate pCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
+ length + 1);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "No memory for pCAL purpose");
+ return;
+ }
+
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
+
+ png_debug(3, "Finding end of pCAL purpose string");
+ for (buf = png_ptr->chunkdata; *buf; buf++)
+ /* Empty loop */ ;
+
+ endptr = png_ptr->chunkdata + slength;
+
+ /* We need to have at least 12 bytes after the purpose string
+ * in order to get the parameter information.
+ */
+ if (endptr <= buf + 12)
+ {
+ png_warning(png_ptr, "Invalid pCAL data");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ 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_warning(png_ptr, "Invalid pCAL parameters for equation type");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ else if (type >= PNG_EQUATION_LAST)
+ {
+ png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
+ }
+
+ for (buf = units; *buf; buf++)
+ /* Empty loop to move past the units string. */ ;
+
+ png_debug(3, "Allocating pCAL parameters array");
+
+ params = (png_charpp)png_malloc_warn(png_ptr,
+ (png_size_t)(nparams * png_sizeof(png_charp)));
+
+ if (params == NULL)
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_warning(png_ptr, "No memory for pCAL params");
+ return;
+ }
+
+ /* Get pointers to the start of each parameter string. */
+ for (i = 0; i < (int)nparams; i++)
+ {
+ buf++; /* Skip the null string terminator from previous parameter. */
+
+ png_debug1(3, "Reading pCAL parameter %d", i);
+
+ for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++)
+ /* Empty loop to move past each parameter string */ ;
+
+ /* Make sure we haven't run out of data yet */
+ if (buf > endptr)
+ {
+ png_warning(png_ptr, "Invalid pCAL data");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, params);
+ return;
+ }
+ }
+
+ png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
+ units, params);
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, params);
+}
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+/* Read the sCAL chunk */
+void /* PRIVATE */
+png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_size_t slength, i;
+ int state;
+
+ png_debug(1, "in png_handle_sCAL");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sCAL");
+
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sCAL after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
+ {
+ png_warning(png_ptr, "Duplicate sCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ /* Need unit type, width, \0, height: minimum 4 bytes */
+ else if (length < 4)
+ {
+ png_warning(png_ptr, "sCAL chunk too short");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
+ length + 1);
+
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "Out of memory while processing sCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+ png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ /* Validate the unit. */
+ if (png_ptr->chunkdata[0] != 1 && png_ptr->chunkdata[0] != 2)
+ {
+ png_warning(png_ptr, "Invalid sCAL ignored: invalid unit");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ 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_ptr->chunkdata, slength, &state, &i) ||
+ i >= slength || png_ptr->chunkdata[i++] != 0)
+ png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format");
+
+ else if (!PNG_FP_IS_POSITIVE(state))
+ png_warning(png_ptr, "Invalid sCAL chunk ignored: non-positive width");
+
+ else
+ {
+ png_size_t heighti = i;
+
+ state = 0;
+ if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+ i != slength)
+ png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format");
+
+ else if (!PNG_FP_IS_POSITIVE(state))
+ png_warning(png_ptr,
+ "Invalid sCAL chunk ignored: non-positive height");
+
+ else
+ /* This is the (only) success case. */
+ png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0],
+ png_ptr->chunkdata+1, png_ptr->chunkdata+heighti);
+ }
+
+ /* Clean up - just free the temporarily allocated buffer. */
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+}
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+void /* PRIVATE */
+png_handle_tIME(png_structp png_ptr, png_infop 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_error(png_ptr, "Out of place tIME chunk");
+
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
+ {
+ png_warning(png_ptr, "Duplicate tIME chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ if (length != 7)
+ {
+ png_warning(png_ptr, "Incorrect tIME chunk length");
+ png_crc_finish(png_ptr, length);
+ 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_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp key;
+ png_charp text;
+ png_uint_32 skip = 0;
+ png_size_t slength;
+ int ret;
+
+ 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_warning(png_ptr, "No space in chunk cache for tEXt");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before tEXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "tEXt chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "No memory to process text chunk");
+ return;
+ }
+
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ key = png_ptr->chunkdata;
+
+ key[slength] = 0x00;
+
+ for (text = key; *text; text++)
+ /* Empty loop to find end of key */ ;
+
+ if (text != key + slength)
+ text++;
+
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ png_sizeof(png_text));
+
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process text chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr->key = key;
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+ text_ptr->itxt_length = 0;
+ text_ptr->text = text;
+ text_ptr->text_length = png_strlen(text);
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ png_free(png_ptr, text_ptr);
+
+ if (ret)
+ 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_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp text;
+ int comp_type;
+ int ret;
+ png_size_t slength, prefix_len, data_len;
+
+ 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_warning(png_ptr, "No space in chunk cache for zTXt");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before zTXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ /* We will no doubt have problems with chunks even half this size, but
+ * there is no hard and fast rule to tell us where to stop.
+ */
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "zTXt chunk too large to fit in memory");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "Out of memory processing zTXt chunk");
+ return;
+ }
+
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (text = png_ptr->chunkdata; *text; text++)
+ /* Empty loop */ ;
+
+ /* zTXt must have some text after the chunkdataword */
+ if (text >= png_ptr->chunkdata + slength - 2)
+ {
+ png_warning(png_ptr, "Truncated zTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ else
+ {
+ comp_type = *(++text);
+
+ if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
+ {
+ png_warning(png_ptr, "Unknown compression type in zTXt chunk");
+ comp_type = PNG_TEXT_COMPRESSION_zTXt;
+ }
+
+ text++; /* Skip the compression_method byte */
+ }
+
+ prefix_len = text - png_ptr->chunkdata;
+
+ png_decompress_chunk(png_ptr, comp_type,
+ (png_size_t)length, prefix_len, &data_len);
+
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ png_sizeof(png_text));
+
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process zTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ text_ptr->compression = comp_type;
+ text_ptr->key = png_ptr->chunkdata;
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+ text_ptr->itxt_length = 0;
+ text_ptr->text = png_ptr->chunkdata + prefix_len;
+ text_ptr->text_length = data_len;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, text_ptr);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+
+ if (ret)
+ png_error(png_ptr, "Insufficient memory to store zTXt chunk");
+}
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp key, lang, text, lang_key;
+ int comp_flag;
+ int comp_type = 0;
+ int ret;
+ png_size_t slength, prefix_len, data_len;
+
+ 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_warning(png_ptr, "No space in chunk cache for iTXt");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before iTXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ /* We will no doubt have problems with chunks even half this size, but
+ * there is no hard and fast rule to tell us where to stop.
+ */
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "iTXt chunk too large to fit in memory");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#endif
+
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+
+ if (png_ptr->chunkdata == NULL)
+ {
+ png_warning(png_ptr, "No memory to process iTXt chunk");
+ return;
+ }
+
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ png_ptr->chunkdata[slength] = 0x00;
+
+ for (lang = png_ptr->chunkdata; *lang; lang++)
+ /* Empty loop */ ;
+
+ lang++; /* Skip NUL separator */
+
+ /* iTXt must have a language tag (possibly empty), two compression bytes,
+ * translated keyword (possibly empty), and possibly some text after the
+ * keyword
+ */
+
+ if (lang >= png_ptr->chunkdata + slength - 3)
+ {
+ png_warning(png_ptr, "Truncated iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ else
+ {
+ comp_flag = *lang++;
+ comp_type = *lang++;
+ }
+
+ for (lang_key = lang; *lang_key; lang_key++)
+ /* Empty loop */ ;
+
+ lang_key++; /* Skip NUL separator */
+
+ if (lang_key >= png_ptr->chunkdata + slength)
+ {
+ png_warning(png_ptr, "Truncated iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ for (text = lang_key; *text; text++)
+ /* Empty loop */ ;
+
+ text++; /* Skip NUL separator */
+
+ if (text >= png_ptr->chunkdata + slength)
+ {
+ png_warning(png_ptr, "Malformed iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ prefix_len = text - png_ptr->chunkdata;
+
+ key=png_ptr->chunkdata;
+
+ if (comp_flag)
+ png_decompress_chunk(png_ptr, comp_type,
+ (size_t)length, prefix_len, &data_len);
+
+ else
+ data_len = png_strlen(png_ptr->chunkdata + prefix_len);
+
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ png_sizeof(png_text));
+
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process iTXt chunk");
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+ return;
+ }
+
+ text_ptr->compression = (int)comp_flag + 1;
+ text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
+ text_ptr->lang = png_ptr->chunkdata + (lang - key);
+ text_ptr->itxt_length = data_len;
+ text_ptr->text_length = 0;
+ text_ptr->key = png_ptr->chunkdata;
+ text_ptr->text = png_ptr->chunkdata + prefix_len;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, text_ptr);
+ png_free(png_ptr, png_ptr->chunkdata);
+ png_ptr->chunkdata = NULL;
+
+ if (ret)
+ png_error(png_ptr, "Insufficient memory to store iTXt chunk");
+}
+#endif
+
+/* This function is called when we haven't found a handler for a
+ * chunk. If there isn't a problem with the chunk itself (ie bad
+ * chunk name, CRC, or a critical chunk), the chunk is silently ignored
+ * -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
+ * case it will be saved away to be written out later.
+ */
+void /* PRIVATE */
+png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_uint_32 skip = 0;
+
+ png_debug(1, "in png_handle_unknown");
+
+#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 unknown chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ PNG_IDAT;
+
+ if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* Not an IDAT */
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ }
+
+ if (!(png_ptr->chunk_name[0] & 0x20))
+ {
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ && png_ptr->read_user_chunk_fn == NULL
+#endif
+ )
+#endif
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ }
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ || (png_ptr->read_user_chunk_fn != NULL)
+#endif
+ )
+ {
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "unknown chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_memcpy((png_charp)png_ptr->unknown_chunk.name,
+ (png_charp)png_ptr->chunk_name,
+ png_sizeof(png_ptr->unknown_chunk.name));
+
+ png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1]
+ = '\0';
+
+ png_ptr->unknown_chunk.size = (png_size_t)length;
+
+ if (length == 0)
+ png_ptr->unknown_chunk.data = NULL;
+
+ else
+ {
+ png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
+ png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
+ }
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ if (png_ptr->read_user_chunk_fn != NULL)
+ {
+ /* Callback to user unknown chunk handler */
+ int ret;
+
+ ret = (*(png_ptr->read_user_chunk_fn))
+ (png_ptr, &png_ptr->unknown_chunk);
+
+ if (ret < 0)
+ png_chunk_error(png_ptr, "error in user chunk");
+
+ if (ret == 0)
+ {
+ if (!(png_ptr->chunk_name[0] & 0x20))
+ {
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS)
+#endif
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ }
+
+ png_set_unknown_chunks(png_ptr, info_ptr,
+ &png_ptr->unknown_chunk, 1);
+ }
+ }
+
+ else
+#endif
+ png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
+
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
+
+ else
+#endif
+ skip = length;
+
+ png_crc_finish(png_ptr, skip);
+
+#ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+ PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
+#endif
+}
+
+/* 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.
+ */
+
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+
+void /* PRIVATE */
+png_check_chunk_name(png_structp png_ptr, png_const_bytep chunk_name)
+{
+ png_debug(1, "in png_check_chunk_name");
+ if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
+ isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
+ {
+ png_chunk_error(png_ptr, "invalid chunk type");
+ }
+}
+
+/* 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 mask value.
+ * The mask value describes which pixels are to be combined with
+ * the row. The pattern always repeats every 8 pixels, so just 8
+ * bits are needed. A one indicates the pixel is to be combined,
+ * a zero indicates the pixel is to be skipped. This is in addition
+ * to any alpha or transparency value associated with the pixel. If
+ * you want all pixels to be combined, pass 0xff (255) in mask.
+ */
+
+void /* PRIVATE */
+png_combine_row(png_structp png_ptr, png_bytep row, int mask)
+{
+ png_debug(1, "in png_combine_row");
+
+ /* Added in 1.5.4: the row_info 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(png_ptr->row_info.pixel_depth, png_ptr->width))
+ png_error(png_ptr, "internal row size calculation error");
+
+ if (mask == 0xff)
+ {
+ png_memcpy(row, png_ptr->row_buf + 1,
+ PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
+ }
+
+ else
+ {
+ switch (png_ptr->row_info.pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ int s_inc, s_start, s_end;
+ int m = 0x80;
+ int shift;
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 7;
+ s_inc = 1;
+ }
+
+ else
+#endif
+ {
+ s_start = 7;
+ s_end = 0;
+ s_inc = -1;
+ }
+
+ shift = s_start;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ int value;
+
+ value = (*sp >> shift) & 0x01;
+ *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+
+ else
+ shift += s_inc;
+
+ if (m == 1)
+ m = 0x80;
+
+ else
+ m >>= 1;
+ }
+ break;
+ }
+
+ case 2:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ int s_start, s_end, s_inc;
+ int m = 0x80;
+ int shift;
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+ int value;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 6;
+ s_inc = 2;
+ }
+
+ else
+#endif
+ {
+ s_start = 6;
+ s_end = 0;
+ s_inc = -2;
+ }
+
+ shift = s_start;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+
+ else
+ shift += s_inc;
+
+ if (m == 1)
+ m = 0x80;
+
+ else
+ m >>= 1;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ int s_start, s_end, s_inc;
+ int m = 0x80;
+ int shift;
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+ int value;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 4;
+ s_inc = 4;
+ }
+
+ else
+#endif
+ {
+ s_start = 4;
+ s_end = 0;
+ s_inc = -4;
+ }
+ shift = s_start;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ value = (*sp >> shift) & 0xf;
+ *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+
+ else
+ shift += s_inc;
+
+ if (m == 1)
+ m = 0x80;
+
+ else
+ m >>= 1;
+ }
+ break;
+ }
+
+ default:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+ png_byte m = 0x80;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ png_memcpy(dp, sp, pixel_bytes);
+ }
+
+ sp += pixel_bytes;
+ dp += pixel_bytes;
+
+ if (m == 1)
+ m = 0x80;
+
+ else
+ m >>= 1;
+ }
+ break;
+ }
+ }
+ }
+}
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void /* PRIVATE */
+png_do_read_interlace(png_structp png_ptr)
+{
+ png_row_infop row_info = &(png_ptr->row_info);
+ png_bytep row = png_ptr->row_buf + 1;
+ int pass = png_ptr->pass;
+ png_uint_32 transformations = png_ptr->transformations;
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+ /* Offset to next interlace block */
+ 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++)
+ {
+ *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+
+ 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++)
+ {
+ *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+
+ 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) & 0xf);
+ int j;
+
+ for (j = 0; j < jstop; j++)
+ {
+ *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+
+ 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];
+ int j;
+
+ png_memcpy(v, sp, pixel_bytes);
+
+ for (j = 0; j < jstop; j++)
+ {
+ png_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 */
+
+void /* PRIVATE */
+png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row, int filter)
+{
+ png_debug(1, "in png_read_filter_row");
+ png_debug2(2, "row = %u, filter = %d", png_ptr->row_number, filter);
+ switch (filter)
+ {
+ case PNG_FILTER_VALUE_NONE:
+ break;
+
+ case PNG_FILTER_VALUE_SUB:
+ {
+ 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_bytep lp = row;
+
+ for (i = bpp; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ case PNG_FILTER_VALUE_UP:
+ {
+ 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++;
+ }
+ break;
+ }
+ case PNG_FILTER_VALUE_AVG:
+ {
+ png_size_t i;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+ png_bytep lp = 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++ + *lp++) / 2 ) & 0xff);
+
+ rp++;
+ }
+ break;
+ }
+ case PNG_FILTER_VALUE_PAETH:
+ {
+ png_size_t i;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+ png_bytep lp = row;
+ png_const_bytep cp = 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++)) & 0xff);
+ rp++;
+ }
+
+ for (i = 0; i < istop; i++) /* Use leftover rp,pp */
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ a = *lp++;
+ b = *pp++;
+ c = *cp++;
+
+ 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 (pa <= pb && pa <= pc)
+ p = a;
+
+ else if (pb <= pc)
+ p = b;
+
+ else
+ p = c;
+ */
+
+ p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c;
+
+ *rp = (png_byte)(((int)(*rp) + p) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ default:
+ png_error(png_ptr, "Ignoring bad adaptive filter type");
+ /*NOT REACHED */
+ break;
+ }
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void /* PRIVATE */
+png_read_finish_row(png_structp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ PNG_CONST int 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;
+
+ png_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 */
+
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+ {
+ PNG_IDAT;
+ char extra;
+ int ret;
+
+ png_ptr->zstream.next_out = (Byte *)&extra;
+ png_ptr->zstream.avail_out = (uInt)1;
+
+ for (;;)
+ {
+ if (!(png_ptr->zstream.avail_in))
+ {
+ while (!png_ptr->idat_size)
+ {
+ png_crc_finish(png_ptr, 0);
+ png_ptr->idat_size = png_read_chunk_header(png_ptr);
+ if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ png_error(png_ptr, "Not enough image data");
+ }
+
+ png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_in = png_ptr->zbuf;
+
+ if (png_ptr->zbuf_size > png_ptr->idat_size)
+ png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
+
+ png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
+ png_ptr->idat_size -= png_ptr->zstream.avail_in;
+ }
+
+ ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+
+ if (ret == Z_STREAM_END)
+ {
+ if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
+ png_ptr->idat_size)
+ png_warning(png_ptr, "Extra compressed data");
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
+
+ if (ret != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
+ "Decompression Error");
+
+ if (!(png_ptr->zstream.avail_out))
+ {
+ png_warning(png_ptr, "Extra compressed data");
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
+
+ }
+ png_ptr->zstream.avail_out = 0;
+ }
+
+ if (png_ptr->idat_size || png_ptr->zstream.avail_in)
+ png_warning(png_ptr, "Extra compression data");
+
+ inflateReset(&png_ptr->zstream);
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+
+void /* PRIVATE */
+png_read_start_row(png_structp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ PNG_CONST int 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");
+ png_ptr->zstream.avail_in = 0;
+#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;
+
+#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_PALETTE)
+ max_pixel_depth = 32;
+
+ else 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)
+ {
+ 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
+
+ /* 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);
+
+ 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->old_big_row_buf_size = 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.
+ */
+ png_ptr->row_buf = png_ptr->big_row_buf + 32 -
+ (((png_alloc_size_t)png_ptr->big_row_buf + 15) & 0x0F);
+
+ png_ptr->old_big_row_buf_size = row_bytes + 48;
+#else
+ /* Use 32 bytes of padding before and 16 bytes after row_buf. */
+ png_ptr->row_buf = png_ptr->big_row_buf + 32;
+#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");
+
+ if (png_ptr->rowbytes + 1 > png_ptr->old_prev_row_size)
+ {
+ png_free(png_ptr, png_ptr->prev_row);
+
+ png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
+
+ png_ptr->old_prev_row_size = png_ptr->rowbytes + 1;
+ }
+
+ png_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);
+
+ png_ptr->flags |= PNG_FLAG_ROW_INIT;
+}
+#endif /* PNG_READ_SUPPORTED */
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