+ if ((current_buffer != last_undo_buffer)
+ /* Don't call Fundo_boundary for the first change. Otherwise we
+ risk overwriting last_boundary_position in Fundo_boundary with
+ PT of the current buffer and as a consequence not insert an
+ undo boundary because last_boundary_position will equal pt in
+ the test at the end of the present function (Bug#731). */
+ && (MODIFF > SAVE_MODIFF))