anchor.diff:      process_flag(trap_exit, true),
       gen_server:start_link({local, refactor_undo}, ?MODULE, [], []).
   
  -%%-spec(undo/0::() ->
  -%%	     {ok, [filename()]}).
  +-spec(undo/0::() ->
  + 	     {ok, [filename()], string(), filename()}).
   undo() ->
       gen_server:call(refactor_undo, undo).
      
  -%%-spec(add_to_history/1::([{filename(), filename(), binary()}]) -> ok).
  +
  +%%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}}).
  
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: 		    end;
  		false ->
  		    case IsNew of 
  			true -> %% This should not happen.
  			    file:delete(OldFileName),
  			    file:delete(NewFileName),
  			    undo_files(T);
  