anchor.diff:  					  end,
   					  Files),
   	    FilesToRename = [{NewFileName, OldFileName}||
  -				{{OldFileName, NewFileName, _}, _Con}<-Files, 
  +				{{OldFileName, NewFileName, _}, _Con}<-Files,  
   				OldFileName/=NewFileName],
   	    {reply,{ok, FilesToChange, FilesToRename}, State}
       end.
  -
   %%--------------------------------------------------------------------
   %% Function: handle_cast(Msg, State) -> {noreply, State} |
   %%                                      {noreply, State, Timeout} |
   %%                                      {stop, Reason, State}
   %% Description: Handling cast messages
   %%--------------------------------------------------------------------
  -handle_cast({add, {Files, LogMsg, CurFile}},_State=#state{history=History}) ->
  +handle_cast({add, {Files, LogMsg, CurFile}},State=#state{history=History}) ->
       History1=lists:sublist([{Files, LogMsg, CurFile}|History],20),
  -    {noreply, #state{history=History1}}.
  -	
  -%%--------------------------------------------------------------------
  +    {noreply, State#state{history=History1}}.
  +
  +%%-------------------------------------------------------------------
   %% Function: handle_info(Info, State) -> {noreply, State} |
   %%                                       {noreply, State, Timeout} |
   %%                                       {stop, Reason, State}
  
positive.code: %%% File    : wrangler_undo_server.erl
  %%% Author  :  <Huiqing>
  %% Author contact: hl@kent.ac.uk, sjt@kent.ac.uk
  %%%-------------------------------------------------------------------
  %%%@private
  %%%@hidden
  -module(wrangler_undo_server).
  
  -behaviour(gen_server).
  
negative.code: 						 [OldFileName, NewFileName]
  					 end
  				 end,Files),
  	    {reply,{ok, Modified}, State#state{history=T}}
      end;
  handle_call(files_to_change, _From, State=#state{history=History}) ->
      case History of 
  