anchor.diff:  
   type
     // widget options
  -  TfpgComboOption = (wo_FocusItemTriggersOnChange);
  +  TfpgComboOption = (wo_FocusItemTriggersOnChange, wo_AllowUserBlank);
     TfpgComboOptions = set of TfpgComboOption;
   
   
  
positive.code: begin
    if FItems.Count = 0 then
      FocusItem := -1;
  end;
  
  procedure TfpgBaseComboBox.HandleKeyPress(var keycode: word;
  
negative.code: 
        keyUp:
          begin
            if (FocusItem = 0) and (wo_AllowUserBlank in FOptions) then
              FocusItem := FocusItem - 1
            else if FocusItem > 0 then
              FocusItem := FocusItem - 1;
            if old <> FocusItem then
              DoOnChange;
            consumed := True;
  