- if(png_ptr->read_user_chunk_fn != NULL)
- {
- /* callback to user unknown chunk handler */
- if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 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, &chunk, 1);
- }
- else
+ 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
+ png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);