diff options
Diffstat (limited to 'drivers/png/pngpread.c')
| -rw-r--r-- | drivers/png/pngpread.c | 695 |
1 files changed, 38 insertions, 657 deletions
diff --git a/drivers/png/pngpread.c b/drivers/png/pngpread.c index 20d3f236e1..9cf987d7e3 100644 --- a/drivers/png/pngpread.c +++ b/drivers/png/pngpread.c @@ -1,8 +1,8 @@ /* pngpread.c - read a png file in push mode * - * Last changed in libpng 1.5.7 [December 15, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.23 [July 23, 2015] + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -19,7 +19,6 @@ #define PNG_READ_SIG_MODE 0 #define PNG_READ_CHUNK_MODE 1 #define PNG_READ_IDAT_MODE 2 -#define PNG_SKIP_MODE 3 #define PNG_READ_tEXt_MODE 4 #define PNG_READ_zTXt_MODE 5 #define PNG_READ_DONE_MODE 6 @@ -49,7 +48,7 @@ png_process_data_pause(png_structp png_ptr, int save) /* It's easiest for the caller if we do the save, then the caller doesn't * have to supply the same data again: */ - if (save) + if (save != 0) png_push_save_buffer(png_ptr); else { @@ -71,32 +70,15 @@ png_process_data_pause(png_structp png_ptr, int save) png_uint_32 PNGAPI png_process_data_skip(png_structp png_ptr) { - png_uint_32 remaining = 0; - - if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE && - png_ptr->skip_length > 0) - { - /* At the end of png_process_data the buffer size must be 0 (see the loop - * above) so we can detect a broken call here: - */ - if (png_ptr->buffer_size != 0) - png_error(png_ptr, - "png_process_data_skip called inside png_process_data"); - - /* If is impossible for there to be a saved buffer at this point - - * otherwise we could not be in SKIP mode. This will also happen if - * png_process_skip is called inside png_process_data (but only very - * rarely.) - */ - if (png_ptr->save_buffer_size != 0) - png_error(png_ptr, "png_process_data_skip called with saved data"); - - remaining = png_ptr->skip_length; - png_ptr->skip_length = 0; - png_ptr->process_mode = PNG_READ_CHUNK_MODE; - } - - return remaining; + /* TODO: Deprecate and remove this API. + * Somewhere the implementation of this seems to have been lost, + * or abandoned. It was only to support some internal back-door access + * to png_struct) in libpng-1.4.x. + */ + png_warning(png_ptr, + "png_process_data_skip is not implemented in any current version" + " of libpng"); + return 0; } /* What we do with the incoming data depends on what we were previously @@ -128,36 +110,6 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr) break; } -#ifdef PNG_READ_tEXt_SUPPORTED - case PNG_READ_tEXt_MODE: - { - png_push_read_tEXt(png_ptr, info_ptr); - break; - } - -#endif -#ifdef PNG_READ_zTXt_SUPPORTED - case PNG_READ_zTXt_MODE: - { - png_push_read_zTXt(png_ptr, info_ptr); - break; - } - -#endif -#ifdef PNG_READ_iTXt_SUPPORTED - case PNG_READ_iTXt_MODE: - { - png_push_read_iTXt(png_ptr, info_ptr); - break; - } - -#endif - case PNG_SKIP_MODE: - { - png_push_crc_finish(png_ptr); - break; - } - default: { png_ptr->buffer_size = 0; @@ -175,8 +127,8 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr) void /* PRIVATE */ png_push_read_sig(png_structp png_ptr, png_infop info_ptr) { - png_size_t num_checked = png_ptr->sig_bytes, - num_to_check = 8 - num_checked; + png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */ + num_to_check = 8 - num_checked; if (png_ptr->buffer_size < num_to_check) { @@ -196,6 +148,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr) else png_error(png_ptr, "PNG file corrupted by ASCII conversion"); } + else { if (png_ptr->sig_bytes >= 8) @@ -305,8 +258,8 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_error(png_ptr, "Missing PLTE before IDAT"); } } - #endif + else if (chunk_name == png_PLTE) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) @@ -543,7 +496,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); + png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); } #endif @@ -556,7 +509,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); + png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); } #endif @@ -569,10 +522,11 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); + png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); } #endif + else { if (png_ptr->push_length + 4 > png_ptr->buffer_size) @@ -580,80 +534,12 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_push_save_buffer(png_ptr); return; } - png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); } png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; } -void /* PRIVATE */ -png_push_crc_skip(png_structp png_ptr, png_uint_32 skip) -{ - png_ptr->process_mode = PNG_SKIP_MODE; - png_ptr->skip_length = skip; -} - -void /* PRIVATE */ -png_push_crc_finish(png_structp png_ptr) -{ - if (png_ptr->skip_length && png_ptr->save_buffer_size) - { - png_size_t save_size = png_ptr->save_buffer_size; - png_uint_32 skip_length = png_ptr->skip_length; - - /* We want the smaller of 'skip_length' and 'save_buffer_size', but - * they are of different types and we don't know which variable has the - * fewest bits. Carefully select the smaller and cast it to the type of - * the larger - this cannot overflow. Do not cast in the following test - * - it will break on either 16 or 64 bit platforms. - */ - if (skip_length < save_size) - save_size = (png_size_t)skip_length; - - else - skip_length = (png_uint_32)save_size; - - png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); - - png_ptr->skip_length -= skip_length; - png_ptr->buffer_size -= save_size; - png_ptr->save_buffer_size -= save_size; - png_ptr->save_buffer_ptr += save_size; - } - if (png_ptr->skip_length && png_ptr->current_buffer_size) - { - png_size_t save_size = png_ptr->current_buffer_size; - png_uint_32 skip_length = png_ptr->skip_length; - - /* We want the smaller of 'skip_length' and 'current_buffer_size', here, - * the same problem exists as above and the same solution. - */ - if (skip_length < save_size) - save_size = (png_size_t)skip_length; - - else - skip_length = (png_uint_32)save_size; - - png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); - - png_ptr->skip_length -= skip_length; - png_ptr->buffer_size -= save_size; - png_ptr->current_buffer_size -= save_size; - png_ptr->current_buffer_ptr += save_size; - } - if (!png_ptr->skip_length) - { - if (png_ptr->buffer_size < 4) - { - png_push_save_buffer(png_ptr); - return; - } - - png_crc_finish(png_ptr, 0); - png_ptr->process_mode = PNG_READ_CHUNK_MODE; - } -} - void PNGCBAPI png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) { @@ -663,6 +549,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) return; ptr = buffer; + if (png_ptr->save_buffer_size) { png_size_t save_size; @@ -680,6 +567,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) png_ptr->save_buffer_size -= save_size; png_ptr->save_buffer_ptr += save_size; } + if (length && png_ptr->current_buffer_size) { png_size_t save_size; @@ -709,6 +597,7 @@ png_push_save_buffer(png_structp png_ptr) png_bytep dp; istop = png_ptr->save_buffer_size; + for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; i < istop; i++, sp++, dp++) { @@ -716,6 +605,7 @@ png_push_save_buffer(png_structp png_ptr) } } } + if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > png_ptr->save_buffer_max) { @@ -730,8 +620,7 @@ png_push_save_buffer(png_structp png_ptr) new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; old_buffer = png_ptr->save_buffer; - png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, - (png_size_t)new_max); + png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, new_max); if (png_ptr->save_buffer == NULL) { @@ -743,6 +632,7 @@ png_push_save_buffer(png_structp png_ptr) png_free(png_ptr, old_buffer); png_ptr->save_buffer_max = new_max; } + if (png_ptr->current_buffer_size) { png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, @@ -750,6 +640,7 @@ png_push_save_buffer(png_structp png_ptr) png_ptr->save_buffer_size += png_ptr->current_buffer_size; png_ptr->current_buffer_size = 0; } + png_ptr->save_buffer_ptr = png_ptr->save_buffer; png_ptr->buffer_size = 0; } @@ -851,6 +742,7 @@ png_push_read_IDAT(png_structp png_ptr) png_ptr->current_buffer_size -= save_size; png_ptr->current_buffer_ptr += save_size; } + if (!png_ptr->idat_size) { if (png_ptr->buffer_size < 4) @@ -911,6 +803,12 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, */ ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH); + /* Hack, added in 1.5.18: the progressive reader does not reset + * png_ptr->zstream, so any attempt to use it after the last IDAT fails + * (silently). This allows the read code to do the reset when required. + */ + png_ptr->flags |= PNG_FLAG_ZSTREAM_PROGRESSIVE; + /* Check for any failure before proceeding. */ if (ret != Z_OK && ret != Z_STREAM_END) { @@ -1201,6 +1099,7 @@ png_push_process_row(png_structp png_ptr) void /* PRIVATE */ png_read_push_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 */ @@ -1219,6 +1118,7 @@ png_read_push_finish_row(png_structp png_ptr) * it, uncomment it here and in png.h static PNG_CONST png_byte FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; */ +#endif png_ptr->row_number++; if (png_ptr->row_number < png_ptr->num_rows) @@ -1262,525 +1162,6 @@ png_read_push_finish_row(png_structp png_ptr) #endif /* PNG_READ_INTERLACING_SUPPORTED */ } -#ifdef PNG_READ_tEXt_SUPPORTED -void /* PRIVATE */ -png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 - length) -{ - if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) - { - PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ - png_error(png_ptr, "Out of place tEXt"); - /* NOT REACHED */ - } - -#ifdef PNG_MAX_MALLOC_64K - png_ptr->skip_length = 0; /* This may not be necessary */ - - if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ - { - png_warning(png_ptr, "tEXt chunk too large to fit in memory"); - png_ptr->skip_length = length - (png_uint_32)65535L; - length = (png_uint_32)65535L; - } -#endif - - png_ptr->current_text = (png_charp)png_malloc(png_ptr, - (png_size_t)(length + 1)); - png_ptr->current_text[length] = '\0'; - png_ptr->current_text_ptr = png_ptr->current_text; - png_ptr->current_text_size = (png_size_t)length; - png_ptr->current_text_left = (png_size_t)length; - png_ptr->process_mode = PNG_READ_tEXt_MODE; -} - -void /* PRIVATE */ -png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr) -{ - if (png_ptr->buffer_size && png_ptr->current_text_left) - { - png_size_t text_size; - - if (png_ptr->buffer_size < png_ptr->current_text_left) - text_size = png_ptr->buffer_size; - - else - text_size = png_ptr->current_text_left; - - png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); - png_ptr->current_text_left -= text_size; - png_ptr->current_text_ptr += text_size; - } - if (!(png_ptr->current_text_left)) - { - png_textp text_ptr; - png_charp text; - png_charp key; - int ret; - - if (png_ptr->buffer_size < 4) - { - png_push_save_buffer(png_ptr); - return; - } - - png_push_crc_finish(png_ptr); - -#ifdef PNG_MAX_MALLOC_64K - if (png_ptr->skip_length) - return; -#endif - - key = png_ptr->current_text; - - for (text = key; *text; text++) - /* Empty loop */ ; - - if (text < key + png_ptr->current_text_size) - text++; - - text_ptr = (png_textp)png_malloc(png_ptr, png_sizeof(png_text)); - text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; - text_ptr->key = key; - text_ptr->itxt_length = 0; - text_ptr->lang = NULL; - text_ptr->lang_key = NULL; - text_ptr->text = text; - - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - - png_free(png_ptr, key); - png_free(png_ptr, text_ptr); - png_ptr->current_text = NULL; - - if (ret) - png_warning(png_ptr, "Insufficient memory to store text chunk"); - } -} -#endif - -#ifdef PNG_READ_zTXt_SUPPORTED -void /* PRIVATE */ -png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 - length) -{ - if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) - { - PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ - png_error(png_ptr, "Out of place zTXt"); - /* NOT REACHED */ - } - -#ifdef PNG_MAX_MALLOC_64K - /* We can't handle zTXt chunks > 64K, since we don't have enough space - * to be able to store the uncompressed data. Actually, the threshold - * is probably around 32K, but it isn't as definite as 64K is. - */ - if (length > (png_uint_32)65535L) - { - png_warning(png_ptr, "zTXt chunk too large to fit in memory"); - png_push_crc_skip(png_ptr, length); - return; - } -#endif - - png_ptr->current_text = (png_charp)png_malloc(png_ptr, - (png_size_t)(length + 1)); - png_ptr->current_text[length] = '\0'; - png_ptr->current_text_ptr = png_ptr->current_text; - png_ptr->current_text_size = (png_size_t)length; - png_ptr->current_text_left = (png_size_t)length; - png_ptr->process_mode = PNG_READ_zTXt_MODE; -} - -void /* PRIVATE */ -png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr) -{ - if (png_ptr->buffer_size && png_ptr->current_text_left) - { - png_size_t text_size; - - if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left) - text_size = png_ptr->buffer_size; - - else - text_size = png_ptr->current_text_left; - - png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); - png_ptr->current_text_left -= text_size; - png_ptr->current_text_ptr += text_size; - } - if (!(png_ptr->current_text_left)) - { - png_textp text_ptr; - png_charp text; - png_charp key; - int ret; - png_size_t text_size, key_size; - - if (png_ptr->buffer_size < 4) - { - png_push_save_buffer(png_ptr); - return; - } - - png_push_crc_finish(png_ptr); - - key = png_ptr->current_text; - - for (text = key; *text; text++) - /* Empty loop */ ; - - /* zTXt can't have zero text */ - if (text >= key + png_ptr->current_text_size) - { - png_ptr->current_text = NULL; - png_free(png_ptr, key); - return; - } - - text++; - - if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */ - { - png_ptr->current_text = NULL; - png_free(png_ptr, key); - return; - } - - text++; - - png_ptr->zstream.next_in = (png_bytep)text; - png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size - - (text - key)); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - - key_size = text - key; - text_size = 0; - text = NULL; - ret = Z_STREAM_END; - - while (png_ptr->zstream.avail_in) - { - ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); - if (ret != Z_OK && ret != Z_STREAM_END) - { - inflateReset(&png_ptr->zstream); - png_ptr->zstream.avail_in = 0; - png_ptr->current_text = NULL; - png_free(png_ptr, key); - png_free(png_ptr, text); - return; - } - - if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END) - { - if (text == NULL) - { - text = (png_charp)png_malloc(png_ptr, - (png_ptr->zbuf_size - - png_ptr->zstream.avail_out + key_size + 1)); - - png_memcpy(text + key_size, png_ptr->zbuf, - png_ptr->zbuf_size - png_ptr->zstream.avail_out); - - png_memcpy(text, key, key_size); - - text_size = key_size + png_ptr->zbuf_size - - png_ptr->zstream.avail_out; - - *(text + text_size) = '\0'; - } - - else - { - png_charp tmp; - - tmp = text; - text = (png_charp)png_malloc(png_ptr, text_size + - (png_ptr->zbuf_size - - png_ptr->zstream.avail_out + 1)); - - png_memcpy(text, tmp, text_size); - png_free(png_ptr, tmp); - - png_memcpy(text + text_size, png_ptr->zbuf, - png_ptr->zbuf_size - png_ptr->zstream.avail_out); - - text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; - *(text + text_size) = '\0'; - } - - if (ret != Z_STREAM_END) - { - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - } - } - else - { - break; - } - - if (ret == Z_STREAM_END) - break; - } - - inflateReset(&png_ptr->zstream); - png_ptr->zstream.avail_in = 0; - - if (ret != Z_STREAM_END) - { - png_ptr->current_text = NULL; - png_free(png_ptr, key); - png_free(png_ptr, text); - return; - } - - png_ptr->current_text = NULL; - png_free(png_ptr, key); - key = text; - text += key_size; - - text_ptr = (png_textp)png_malloc(png_ptr, - png_sizeof(png_text)); - text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; - text_ptr->key = key; - text_ptr->itxt_length = 0; - text_ptr->lang = NULL; - text_ptr->lang_key = NULL; - text_ptr->text = text; - - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - - png_free(png_ptr, key); - png_free(png_ptr, text_ptr); - - if (ret) - png_warning(png_ptr, "Insufficient memory to store text chunk"); - } -} -#endif - -#ifdef PNG_READ_iTXt_SUPPORTED -void /* PRIVATE */ -png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 - length) -{ - if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) - { - PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ - png_error(png_ptr, "Out of place iTXt"); - /* NOT REACHED */ - } - -#ifdef PNG_MAX_MALLOC_64K - png_ptr->skip_length = 0; /* This may not be necessary */ - - if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ - { - png_warning(png_ptr, "iTXt chunk too large to fit in memory"); - png_ptr->skip_length = length - (png_uint_32)65535L; - length = (png_uint_32)65535L; - } -#endif - - png_ptr->current_text = (png_charp)png_malloc(png_ptr, - (png_size_t)(length + 1)); - png_ptr->current_text[length] = '\0'; - png_ptr->current_text_ptr = png_ptr->current_text; - png_ptr->current_text_size = (png_size_t)length; - png_ptr->current_text_left = (png_size_t)length; - png_ptr->process_mode = PNG_READ_iTXt_MODE; -} - -void /* PRIVATE */ -png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr) -{ - - if (png_ptr->buffer_size && png_ptr->current_text_left) - { - png_size_t text_size; - - if (png_ptr->buffer_size < png_ptr->current_text_left) - text_size = png_ptr->buffer_size; - - else - text_size = png_ptr->current_text_left; - - png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); - png_ptr->current_text_left -= text_size; - png_ptr->current_text_ptr += text_size; - } - - if (!(png_ptr->current_text_left)) - { - png_textp text_ptr; - png_charp key; - int comp_flag; - png_charp lang; - png_charp lang_key; - png_charp text; - int ret; - - if (png_ptr->buffer_size < 4) - { - png_push_save_buffer(png_ptr); - return; - } - - png_push_crc_finish(png_ptr); - -#ifdef PNG_MAX_MALLOC_64K - if (png_ptr->skip_length) - return; -#endif - - key = png_ptr->current_text; - - for (lang = key; *lang; lang++) - /* Empty loop */ ; - - if (lang < key + png_ptr->current_text_size - 3) - lang++; - - comp_flag = *lang++; - lang++; /* Skip comp_type, always zero */ - - for (lang_key = lang; *lang_key; lang_key++) - /* Empty loop */ ; - - lang_key++; /* Skip NUL separator */ - - text=lang_key; - - if (lang_key < key + png_ptr->current_text_size - 1) - { - for (; *text; text++) - /* Empty loop */ ; - } - - if (text < key + png_ptr->current_text_size) - text++; - - text_ptr = (png_textp)png_malloc(png_ptr, - png_sizeof(png_text)); - - text_ptr->compression = comp_flag + 2; - text_ptr->key = key; - text_ptr->lang = lang; - text_ptr->lang_key = lang_key; - text_ptr->text = text; - text_ptr->text_length = 0; - text_ptr->itxt_length = png_strlen(text); - - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - - png_ptr->current_text = NULL; - - png_free(png_ptr, text_ptr); - if (ret) - png_warning(png_ptr, "Insufficient memory to store iTXt chunk"); - } -} -#endif - -/* This function is called when we haven't found a handler for this - * chunk. If there isn't a problem with the chunk itself (ie a bad chunk - * name or a critical chunk), the chunk is (currently) silently ignored. - */ -void /* PRIVATE */ -png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 - length) -{ - png_uint_32 skip = 0; - png_uint_32 chunk_name = png_ptr->chunk_name; - - if (PNG_CHUNK_CRITICAL(chunk_name)) - { -#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED - if (png_chunk_unknown_handling(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"); - - PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ - } - -#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED - /* TODO: the code below is apparently just using the - * png_struct::unknown_chunk member as a temporarily variable, it should be - * possible to eliminate both it and the temporary buffer. - */ - if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) - { -#ifdef PNG_MAX_MALLOC_64K - if (length > 65535) - { - png_warning(png_ptr, "unknown chunk too large to fit in memory"); - skip = length - 65535; - length = 65535; - } -#endif - /* This is just a record for the user; libpng doesn't use the character - * form of the name. - */ - PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name); - - /* The following cast should be safe because of the check above. */ - 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, - png_ptr->unknown_chunk.size); - png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, - png_ptr->unknown_chunk.size); - } - -#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_CHUNK_CRITICAL(png_ptr->chunk_name)) - if (png_chunk_unknown_handling(png_ptr, chunk_name) != - PNG_HANDLE_CHUNK_ALWAYS) - 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_push_crc_skip(png_ptr, skip); -} - void /* PRIVATE */ png_push_have_info(png_structp png_ptr, png_infop info_ptr) { @@ -1816,7 +1197,7 @@ png_progressive_combine_row (png_structp png_ptr, png_bytep old_row, * it must be png_ptr->row_buf+1 */ if (new_row != NULL) - png_combine_row(png_ptr, old_row, 1/*display*/); + png_combine_row(png_ptr, old_row, 1/*blocky display*/); } #endif /* PNG_READ_INTERLACING_SUPPORTED */ |