src/Pure/PIDE/document.ML

 in
 
 fun edit (old_id: version_id) (new_id: version_id) edits state =
   let
     val old_version = the_version state old_id;
+    val _ = Time.now ();  (* FIXME odd workaround *)
     val new_version = fold edit_nodes edits old_version;
 
     fun update_node name (rev_updates, version, st) =
       let val node = get_node version name in
         (case first_entry NONE (is_changed (get_node old_version name)) node of