anchor.diff:              ?Debug("Guicnt != 0 ~p ~p", [autofilling,<<"more">>]),
               gui_append(#gres{state = autofilling, loop = <<"more">>, focus = -1}, State#state{stack = undefined, replyToFun=ReplyTo})
       end;
  -serve_stack(autofilling, #state{bufCnt=BufCnt,bufBot=BufBot,guiCnt=GuiCnt,guiBot=GuiBot,guiCol=GuiCol, stack = {button, <<">|">>, ReplyTo}} = State) ->
  +serve_stack(_SN, #state{bufCnt=BufCnt,bufBot=BufBot,guiCnt=GuiCnt,guiBot=GuiBot,guiCol=GuiCol, stack = {button, <<">|">>, ReplyTo}} = State) ->
       if
           (BufCnt == 0) -> State;                                    % no data, nothing to do, keep stack
           (BufBot == GuiBot) andalso (GuiCol == false) -> State;     % no new data, nothing to do, keep stack
  
positive.code: filling({button, Button, ReplyTo}=Cmd, #state{bufCnt=0}=State0) ->
      % too quick, defer request .. when we have the first block of data 
      State1 = reply_stack(filling, ReplyTo, State0),
      ?NoDbLog(debug, [], "filling stack ~p", [Button]),
      {next_state, filling, State1#state{stack=Cmd}};
  filling({button, <<"...">>, ReplyTo}, #state{dirtyCnt=DC}=State0) when DC==0 ->
      % close fetch and clear buffers, schedule tail mode
      State1 = reply_stack(filling, ReplyTo, State0),
  
negative.code:     State1 = data_append(filling, {Recs,false},State0),
      NewBufBot = State1#state.bufBot,
      NewGuiBot = State1#state.guiBot,
      State2 = if
          (NewGuiBot == NewBufBot) -> prefetch(filling,State1);
          true ->                     State1
      end,
  