* image.c (jpeg_memory_src): Don't assume string len fits in unsigned.

src/ChangeLog

+2012-09-12  Paul Eggert  <eggert@cs.ucla.edu>
+
+	* image.c (jpeg_memory_src): Don't assume string len fits in unsigned.
+
 2012-09-12  Stefan Monnier  <monnier@iro.umontreal.ca>
 	* eval.c: Add `inhibit-debugger'.

src/image.c

@@ -6181,7 +6181,7 @@ our_memory_skip_input_data (j_decompress_ptr cinfo, long int num_bytes)
    reading the image.  */
 
 static void
-jpeg_memory_src (j_decompress_ptr cinfo, JOCTET *data, unsigned int len)
+jpeg_memory_src (j_decompress_ptr cinfo, JOCTET *data, ptrdiff_t len)
 {
   struct jpeg_source_mgr *src;