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: %%--------------------------------------------------------------------
  start_undo_server() ->
      process_flag(trap_exit, true),
      gen_server:start_link({local, wrangler_undo_server}, ?MODULE, [], []).
  
  %%-spec(undo_emacs/0::() ->
  %%		 {ok, [filename()], string(), filename()}|{error, string()}).
  undo_emacs() ->
      gen_server:call(wrangler_undo_server, undo_emacs).
     
  %%-spec(undo/0::() ->{ok, [filename()]}|{error, string()}).
  undo() ->
      gen_server:call(wrangler_undo_server, undo).
     
  
  %%This is added to make Wrangler work with clearcase.
  %%-spec(files_to_change/0::() ->
  %%	     {ok, [filename()]}).
  files_to_change() ->
      gen_server:call(wrangler_undo_server, files_to_change).
     
  
  %%-spec(add_to_history/1::({filename(), filename(), binary()}) -> ok).
  add_to_history({Files, LogMsg, CurFile})->
      gen_server:cast(wrangler_undo_server, {add, {Files, LogMsg, CurFile}}).
  
  %%====================================================================
  %% gen_server callbacks
  %%====================================================================
  