diff options
Diffstat (limited to 'pngpread.c')
| -rw-r--r-- | pngpread.c | 104 |
1 files changed, 8 insertions, 96 deletions
diff --git a/pngpread.c b/pngpread.c index e9bffb42b..a5da8db0d 100644 --- a/pngpread.c +++ b/pngpread.c @@ -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 @@ -78,32 +77,14 @@ png_process_data_pause(png_structrp png_ptr, int save) png_uint_32 PNGAPI png_process_data_skip(png_structrp 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_app_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 @@ -135,12 +116,6 @@ png_process_some_data(png_structrp png_ptr, png_inforp info_ptr) break; } - case PNG_SKIP_MODE: - { - png_push_crc_finish(png_ptr); - break; - } - default: { png_ptr->buffer_size = 0; @@ -439,69 +414,6 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr) png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; } -void /* PRIVATE */ -png_push_crc_skip(png_structrp 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_structrp png_ptr) -{ - if (png_ptr->skip_length != 0 && png_ptr->save_buffer_size != 0) - { - 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 != 0 && png_ptr->current_buffer_size != 0) - { - 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 == 0) - { - PNG_PUSH_SAVE_BUFFER_IF_LT(4) - 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) { |