+ }
+
+ if (num_chunks_in <= 0)
+ {
+ png_ptr->unknown_default = keep;
+
+ /* '0' means just set the flags, so stop here */
+ if (num_chunks_in == 0)
+ return;
+ }
+
+ if (num_chunks_in < 0)
+ {
+ /* Ignore all unknown chunks and all chunks recognized by
+ * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
+ */
+ static PNG_CONST png_byte chunks_to_ignore[] = {
+ 98, 75, 71, 68, '\0', /* bKGD */
+ 99, 72, 82, 77, '\0', /* cHRM */
+ 103, 65, 77, 65, '\0', /* gAMA */
+ 104, 73, 83, 84, '\0', /* hIST */
+ 105, 67, 67, 80, '\0', /* iCCP */
+ 105, 84, 88, 116, '\0', /* iTXt */
+ 111, 70, 70, 115, '\0', /* oFFs */
+ 112, 67, 65, 76, '\0', /* pCAL */
+ 112, 72, 89, 115, '\0', /* pHYs */
+ 115, 66, 73, 84, '\0', /* sBIT */
+ 115, 67, 65, 76, '\0', /* sCAL */
+ 115, 80, 76, 84, '\0', /* sPLT */
+ 115, 84, 69, 82, '\0', /* sTER */
+ 115, 82, 71, 66, '\0', /* sRGB */
+ 116, 69, 88, 116, '\0', /* tEXt */
+ 116, 73, 77, 69, '\0', /* tIME */
+ 122, 84, 88, 116, '\0' /* zTXt */
+ };
+
+ chunk_list = chunks_to_ignore;
+ num_chunks = (sizeof chunks_to_ignore)/5;
+ }
+
+ else /* num_chunks_in > 0 */
+ {
+ if (chunk_list == NULL)
+ {
+ /* Prior to 1.6.0 this was silently ignored, now it is an app_error
+ * which can be switched off.
+ */
+ png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
+ return;
+ }
+
+ num_chunks = num_chunks_in;
+ }
+
+ old_num_chunks = png_ptr->num_chunk_list;
+ if (png_ptr->chunk_list == NULL)
+ old_num_chunks = 0;
+
+ /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
+ */
+ if (num_chunks + old_num_chunks > UINT_MAX/5)
+ {
+ png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
+ return;
+ }
+
+ /* If these chunks are being reset to the default then no more memory is
+ * required because add_one_chunk above doesn't extend the list if the 'keep'
+ * parameter is the default.
+ */
+ if (keep)
+ {
+ new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
+ 5 * (num_chunks + old_num_chunks)));
+
+ if (old_num_chunks > 0)
+ memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
+ }
+
+ else if (old_num_chunks > 0)
+ new_list = png_ptr->chunk_list;
+
+ else
+ new_list = NULL;
+
+ /* Add the new chunks together with each one's handling code. If the chunk
+ * already exists the code is updated, otherwise the chunk is added to the
+ * end. (In libpng 1.6.0 order no longer matters because this code enforces
+ * the earlier convention that the last setting is the one that is used.)
+ */
+ if (new_list != NULL)
+ {
+ png_const_bytep inlist;
+ png_bytep outlist;
+ unsigned int i;
+
+ for (i=0; i<num_chunks; ++i)
+ old_num_chunks = add_one_chunk(new_list, old_num_chunks,
+ chunk_list+5*i, keep);
+
+ /* Now remove any spurious 'default' entries. */
+ num_chunks = 0;
+ for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
+ if (inlist[4])
+ {
+ if (outlist != inlist)
+ memcpy(outlist, inlist, 5);
+ outlist += 5;
+ ++num_chunks;
+ }
+
+ /* This means the application has removed all the specialized handling. */
+ if (num_chunks == 0)
+ {
+ if (png_ptr->chunk_list != new_list)
+ png_free(png_ptr, new_list);
+
+ new_list = NULL;
+ }
+ }
+
+ else
+ num_chunks = 0;
+
+ png_ptr->num_chunk_list = num_chunks;
+
+ if (png_ptr->chunk_list != new_list)
+ {
+ if (png_ptr->chunk_list != NULL)
+ png_free(png_ptr, png_ptr->chunk_list);
+
+ png_ptr->chunk_list = new_list;
+ }
projects / wxWidgets.git / blobdiff