The attached jpeg causes an infinite loop in il_jpeg.c. skip_input_data. For some reason, src->pub.bytes_in_buffer == 0. Therefore, num_bytes never changes, and the terminating condition never breaks execution of the while loop. Testing
if (num_bytes > 0 && src->pub.bytes_in_buffer > 0)
in line 249 prevents this, but I don't know if this is the cleanest solution.