anchor.diff:  	    Modified = lists:map(fun({{OldFileName, NewFileName,_}, _Con})->
   					 [OldFileName, NewFileName] end,Files),
   	    {reply,{ok, Modified, LogMsg, CurFile}, #state{history=T}}
  +    end;
  +handle_call(files_to_change, _From, State=#state{history=History}) ->
  +    case History of 
  +	[] ->
  +	    [];
  +	[{Files, _LogMsg, _CurFile}|_T] -> 
  +	    ok = undo_files(Files),
  +	    FilesToChange = lists:flatmap(fun({{OldFileName, NewFileName,_}, _Con})->
  +						  case OldFileName==NewFileName of 
  +						      true -> [OldFileName];
  +						      false -> [OldFileName, NewFileName]
  +						  end
  +					  end,
  +					  Files),
  +	    {reply,{ok, FilesToChange}, State}
       end.
   
   %%--------------------------------------------------------------------
  
positive.code: -behaviour(gen_server).
  
  %% API
  -export([start_undo_server/0, undo/0, add_to_history/1]).
  
  %% gen_server callbacks
  -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  
negative.code:     process_flag(trap_exit, true),
      gen_server:start_link({local, refactor_undo}, ?MODULE, [], []).
  
  -spec(undo/0::() ->
   	     {ok, [filename()], string(), filename()}).
  undo() ->
      gen_server:call(refactor_undo, undo).
     
  
  %%This is added to make Wrangler work with clearcase.
  -spec(files_to_change/0::() ->
  	     {ok, [filename()]}).
  files_to_change() ->
      gen_server:call(refactor_undo, files_to_change).
     
  
  -spec(add_to_history/1::([{filename(), filename(), binary()}]) -> ok).
  	     
  add_to_history({Files, LogMsg, CurFile})->
      gen_server:cast(refactor_undo, {add, {Files, LogMsg, CurFile}}).
  