diff options
Diffstat (limited to 'src/3rdparty/libpng/pngpread.c')
| -rw-r--r-- | src/3rdparty/libpng/pngpread.c | 1854 |
1 files changed, 1854 insertions, 0 deletions
diff --git a/src/3rdparty/libpng/pngpread.c b/src/3rdparty/libpng/pngpread.c new file mode 100644 index 0000000000..7b1149bab1 --- /dev/null +++ b/src/3rdparty/libpng/pngpread.c @@ -0,0 +1,1854 @@ + +/* pngpread.c - read a png file in push mode + * + * Last changed in libpng 1.5.1 [February 3, 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 + */ + +#include "pngpriv.h" + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + +/* Push model modes */ +#define PNG_READ_SIG_MODE 0 +#define PNG_READ_CHUNK_MODE 1 +#define PNG_READ_IDAT_MODE 2 +#define PNG_SKIP_MODE 3 +#define PNG_READ_tEXt_MODE 4 +#define PNG_READ_zTXt_MODE 5 +#define PNG_READ_DONE_MODE 6 +#define PNG_READ_iTXt_MODE 7 +#define PNG_ERROR_MODE 8 + +void PNGAPI +png_process_data(png_structp png_ptr, png_infop info_ptr, + png_bytep buffer, png_size_t buffer_size) +{ + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_push_restore_buffer(png_ptr, buffer, buffer_size); + + while (png_ptr->buffer_size) + { + png_process_some_data(png_ptr, info_ptr); + } +} + +png_size_t PNGAPI +png_process_data_pause(png_structp png_ptr, int save) +{ + if (png_ptr != NULL) + { + /* It's easiest for the caller if we do the save, then the caller doesn't + * have to supply the same data again: + */ + if (save) + png_push_save_buffer(png_ptr); + else + { + /* This includes any pending saved bytes: */ + png_size_t remaining = png_ptr->buffer_size; + png_ptr->buffer_size = 0; + + /* So subtract the saved buffer size, unless all the data + * is actually 'saved', in which case we just return 0 + */ + if (png_ptr->save_buffer_size < remaining) + return remaining - png_ptr->save_buffer_size; + } + } + + return 0; +} + +png_uint_32 PNGAPI +png_process_data_skip(png_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; +} + +/* What we do with the incoming data depends on what we were previously + * doing before we ran out of data... + */ +void /* PRIVATE */ +png_process_some_data(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr == NULL) + return; + + switch (png_ptr->process_mode) + { + case PNG_READ_SIG_MODE: + { + png_push_read_sig(png_ptr, info_ptr); + break; + } + + case PNG_READ_CHUNK_MODE: + { + png_push_read_chunk(png_ptr, info_ptr); + break; + } + + case PNG_READ_IDAT_MODE: + { + png_push_read_IDAT(png_ptr); + break; + } + +#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; + break; + } + } +} + +/* Read any remaining signature bytes from the stream and compare them with + * the correct PNG signature. It is possible that this routine is called + * with bytes already read from the signature, either because they have been + * checked by the calling application, or because of multiple calls to this + * routine. + */ +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; + + if (png_ptr->buffer_size < num_to_check) + { + num_to_check = png_ptr->buffer_size; + } + + png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), + num_to_check); + png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check); + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + else + { + if (png_ptr->sig_bytes >= 8) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + } + } +} + +void /* PRIVATE */ +png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) +{ + PNG_IHDR; + PNG_IDAT; + PNG_IEND; + PNG_PLTE; +#ifdef PNG_READ_bKGD_SUPPORTED + PNG_bKGD; +#endif +#ifdef PNG_READ_cHRM_SUPPORTED + PNG_cHRM; +#endif +#ifdef PNG_READ_gAMA_SUPPORTED + PNG_gAMA; +#endif +#ifdef PNG_READ_hIST_SUPPORTED + PNG_hIST; +#endif +#ifdef PNG_READ_iCCP_SUPPORTED + PNG_iCCP; +#endif +#ifdef PNG_READ_iTXt_SUPPORTED + PNG_iTXt; +#endif +#ifdef PNG_READ_oFFs_SUPPORTED + PNG_oFFs; +#endif +#ifdef PNG_READ_pCAL_SUPPORTED + PNG_pCAL; +#endif +#ifdef PNG_READ_pHYs_SUPPORTED + PNG_pHYs; +#endif +#ifdef PNG_READ_sBIT_SUPPORTED + PNG_sBIT; +#endif +#ifdef PNG_READ_sCAL_SUPPORTED + PNG_sCAL; +#endif +#ifdef PNG_READ_sRGB_SUPPORTED + PNG_sRGB; +#endif +#ifdef PNG_READ_sPLT_SUPPORTED + PNG_sPLT; +#endif +#ifdef PNG_READ_tEXt_SUPPORTED + PNG_tEXt; +#endif +#ifdef PNG_READ_tIME_SUPPORTED + PNG_tIME; +#endif +#ifdef PNG_READ_tRNS_SUPPORTED + PNG_tRNS; +#endif +#ifdef PNG_READ_zTXt_SUPPORTED + PNG_zTXt; +#endif + + /* First we make sure we have enough data for the 4 byte chunk name + * and the 4 byte chunk length before proceeding with decoding the + * chunk data. To fully decode each of these chunks, we also make + * sure we have enough data in the buffer for the 4 byte CRC at the + * end of every chunk (except IDAT, which is handled separately). + */ + if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) + { + png_byte chunk_length[4]; + + if (png_ptr->buffer_size < 8) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; + } + + if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + if (png_ptr->mode & PNG_AFTER_IDAT) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + + if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) + { + if (png_ptr->push_length != 13) + png_error(png_ptr, "Invalid IHDR length"); + + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); + } + + else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); + + png_ptr->process_mode = PNG_READ_DONE_MODE; + png_push_have_end(png_ptr, info_ptr); + } + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + png_ptr->mode |= PNG_HAVE_IDAT; + + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); + + if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + png_ptr->mode |= PNG_HAVE_PLTE; + + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + } + } + +#endif + else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); + } + + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + /* If we reach an IDAT chunk, this means we have read all of the + * header chunks, and we can start reading the image (or if this + * is called after the image has been read - we have an error). + */ + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + { + if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) + if (png_ptr->push_length == 0) + return; + + if (png_ptr->mode & PNG_AFTER_IDAT) + png_benign_error(png_ptr, "Too many IDATs found"); + } + + png_ptr->idat_size = png_ptr->push_length; + png_ptr->mode |= PNG_HAVE_IDAT; + png_ptr->process_mode = PNG_READ_IDAT_MODE; + png_push_have_info(png_ptr, info_ptr); + png_ptr->zstream.avail_out = + (uInt) PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1; + png_ptr->zstream.next_out = png_ptr->row_buf; + return; + } + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sBIT_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_cHRM_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sRGB_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_iCCP_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sPLT_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tRNS_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_bKGD_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_hIST_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_pHYs_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_oFFs_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); + } +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sCAL_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tIME_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tEXt_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_zTXt_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_iTXt_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif + else + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + png_push_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) +{ + png_bytep ptr; + + if (png_ptr == NULL) + return; + + ptr = buffer; + if (png_ptr->save_buffer_size) + { + png_size_t save_size; + + if (length < png_ptr->save_buffer_size) + save_size = length; + + else + save_size = png_ptr->save_buffer_size; + + png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size); + length -= save_size; + ptr += save_size; + png_ptr->buffer_size -= save_size; + 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; + + if (length < png_ptr->current_buffer_size) + save_size = length; + + else + save_size = png_ptr->current_buffer_size; + + png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size); + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } +} + +void /* PRIVATE */ +png_push_save_buffer(png_structp png_ptr) +{ + if (png_ptr->save_buffer_size) + { + if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) + { + png_size_t i, istop; + png_bytep sp; + png_bytep dp; + + istop = png_ptr->save_buffer_size; + for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; + i < istop; i++, sp++, dp++) + { + *dp = *sp; + } + } + } + if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > + png_ptr->save_buffer_max) + { + png_size_t new_max; + png_bytep old_buffer; + + if (png_ptr->save_buffer_size > PNG_SIZE_MAX - + (png_ptr->current_buffer_size + 256)) + { + png_error(png_ptr, "Potential overflow of save_buffer"); + } + + new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; + old_buffer = png_ptr->save_buffer; + png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, + (png_size_t)new_max); + + if (png_ptr->save_buffer == NULL) + { + png_free(png_ptr, old_buffer); + png_error(png_ptr, "Insufficient memory for save_buffer"); + } + + png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); + png_free(png_ptr, old_buffer); + png_ptr->save_buffer_max = new_max; + } + if (png_ptr->current_buffer_size) + { + png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, + png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); + png_ptr->save_buffer_size += png_ptr->current_buffer_size; + png_ptr->current_buffer_size = 0; + } + png_ptr->save_buffer_ptr = png_ptr->save_buffer; + png_ptr->buffer_size = 0; +} + +void /* PRIVATE */ +png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, + png_size_t buffer_length) +{ + png_ptr->current_buffer = buffer; + png_ptr->current_buffer_size = buffer_length; + png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; + png_ptr->current_buffer_ptr = png_ptr->current_buffer; +} + +void /* PRIVATE */ +png_push_read_IDAT(png_structp png_ptr) +{ + PNG_IDAT; + if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) + { + png_byte chunk_length[4]; + + if (png_ptr->buffer_size < 8) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; + + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) + png_error(png_ptr, "Not enough compressed data"); + + return; + } + + png_ptr->idat_size = png_ptr->push_length; + } + if (png_ptr->idat_size && png_ptr->save_buffer_size) + { + png_size_t save_size = png_ptr->save_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. Do not cast in the following test - it + * will break on either 16 or 64 bit platforms. + */ + if (idat_size < save_size) + save_size = (png_size_t)idat_size; + + else + idat_size = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_ptr->idat_size -= idat_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + + if (png_ptr->idat_size && png_ptr->current_buffer_size) + { + png_size_t save_size = png_ptr->current_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. + */ + if (idat_size < save_size) + save_size = (png_size_t)idat_size; + + else + idat_size = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_ptr->idat_size -= idat_size; + png_ptr->buffer_size -= save_size; + 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) + { + png_push_save_buffer(png_ptr); + return; + } + + png_crc_finish(png_ptr, 0); + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + png_ptr->mode |= PNG_AFTER_IDAT; + } +} + +void /* PRIVATE */ +png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, + png_size_t buffer_length) +{ + /* The caller checks for a non-zero buffer length. */ + if (!(buffer_length > 0) || buffer == NULL) + png_error(png_ptr, "No IDAT data (internal error)"); + + /* This routine must process all the data it has been given + * before returning, calling the row callback as required to + * handle the uncompressed results. + */ + png_ptr->zstream.next_in = buffer; + png_ptr->zstream.avail_in = (uInt)buffer_length; + + /* Keep going until the decompressed data is all processed + * or the stream marked as finished. + */ + while (png_ptr->zstream.avail_in > 0 && + !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) + { + int ret; + + /* We have data for zlib, but we must check that zlib + * has someplace to put the results. It doesn't matter + * if we don't expect any results -- it may be the input + * data is just the LZ end code. + */ + if (!(png_ptr->zstream.avail_out > 0)) + { + png_ptr->zstream.avail_out = + (uInt) PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1; + + png_ptr->zstream.next_out = png_ptr->row_buf; + } + + /* Using Z_SYNC_FLUSH here means that an unterminated + * LZ stream (a stream with a missing end code) can still + * be handled, otherwise (Z_NO_FLUSH) a future zlib + * implementation might defer output and therefore + * change the current behavior (see comments in inflate.c + * for why this doesn't happen at present with zlib 1.2.5). + */ + ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH); + + /* Check for any failure before proceeding. */ + if (ret != Z_OK && ret != Z_STREAM_END) + { + /* Terminate the decompression. */ + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + + /* This may be a truncated stream (missing or + * damaged end code). Treat that as a warning. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + png_warning(png_ptr, "Truncated compressed data in IDAT"); + + else + png_error(png_ptr, "Decompression error in IDAT"); + + /* Skip the check on unprocessed input */ + return; + } + + /* Did inflate output any data? */ + if (png_ptr->zstream.next_out != png_ptr->row_buf) + { + /* Is this unexpected data after the last row? + * If it is, artificially terminate the LZ output + * here. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + { + /* Extra data. */ + png_warning(png_ptr, "Extra compressed data in IDAT"); + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + + /* Do no more processing; skip the unprocessed + * input check below. + */ + return; + } + + /* Do we have a complete row? */ + if (png_ptr->zstream.avail_out == 0) + png_push_process_row(png_ptr); + } + + /* And check for the end of the stream. */ + if (ret == Z_STREAM_END) + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + } + + /* All the data should have been processed, if anything + * is left at this point we have bytes of IDAT data + * after the zlib end code. + */ + if (png_ptr->zstream.avail_in > 0) + png_warning(png_ptr, "Extra compression data in IDAT"); +} + +void /* PRIVATE */ +png_push_process_row(png_structp png_ptr) +{ + png_ptr->row_info.color_type = png_ptr->color_type; + png_ptr->row_info.width = png_ptr->iwidth; + png_ptr->row_info.channels = png_ptr->channels; + png_ptr->row_info.bit_depth = png_ptr->bit_depth; + png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; + + png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, + png_ptr->row_info.width); + + png_read_filter_row(png_ptr, &(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->prev_row + 1, + (int)(png_ptr->row_buf[0])); + + png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); + + if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) + png_do_read_transformations(png_ptr); + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Blow up interlaced rows to full size */ + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) + { + if (png_ptr->pass < 6) +/* old interface (pre-1.0.9): + png_do_read_interlace(&(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); + */ + png_do_read_interlace(png_ptr); + + switch (png_ptr->pass) + { + case 0: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 0; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */ + } + + if (png_ptr->pass == 2) /* Pass 1 might be empty */ + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 4 && png_ptr->height <= 4) + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 6 && png_ptr->height <= 4) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + case 1: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 1; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 2) /* Skip top 4 generated rows */ + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 2: + { + int i; + + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 4) /* Pass 3 might be empty */ + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 3: + { + int i; + + for (i = 0; i < 4 && png_ptr->pass == 3; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 4) /* Skip top two generated rows */ + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 4: + { + int i; + + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 6) /* Pass 5 might be empty */ + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + case 5: + { + int i; + + for (i = 0; i < 2 && png_ptr->pass == 5; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 6) /* Skip top generated row */ + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + default: + case 6: + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + + if (png_ptr->pass != 6) + break; + + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + } + else +#endif + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } +} + +void /* PRIVATE */ +png_read_push_finish_row(png_structp png_ptr) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; + + /* Height of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h + PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; + */ + + 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 == 1 && png_ptr->width < 5) || + (png_ptr->pass == 3 && png_ptr->width < 3) || + (png_ptr->pass == 5 && png_ptr->width < 2)) + png_ptr->pass++; + + if (png_ptr->pass > 7) + 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) + break; + + 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]; + + } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0); + } +#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; + + if (!(png_ptr->chunk_name[0] & 0x20)) + { +#ifdef PNG_READ_UNKNOWN_CHUNKS_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"); + + PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ + } + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) + { +#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, + (png_size_t)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)) + if (png_handle_as_unknown(png_ptr, 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) +{ + if (png_ptr->info_fn != NULL) + (*(png_ptr->info_fn))(png_ptr, info_ptr); +} + +void /* PRIVATE */ +png_push_have_end(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr->end_fn != NULL) + (*(png_ptr->end_fn))(png_ptr, info_ptr); +} + +void /* PRIVATE */ +png_push_have_row(png_structp png_ptr, png_bytep row) +{ + if (png_ptr->row_fn != NULL) + (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, + (int)png_ptr->pass); +} + +void PNGAPI +png_progressive_combine_row (png_structp png_ptr, png_bytep old_row, + png_const_bytep new_row) +{ + PNG_CONST int FARDATA png_pass_dsp_mask[7] = + {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; + + if (png_ptr == NULL) + return; + + if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */ + png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); +} + +void PNGAPI +png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, + png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, + png_progressive_end_ptr end_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->info_fn = info_fn; + png_ptr->row_fn = row_fn; + png_ptr->end_fn = end_fn; + + png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); +} + +png_voidp PNGAPI +png_get_progressive_ptr(png_const_structp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return png_ptr->io_ptr; +} +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ |