anchor.diff:    FItem: Item;
     I: Integer;
   begin
  +  Items_Clear_Item(FItem);
     Result := FItem;
  -  Items_Clear_Item(Result);
     if HasEmpty(MapItems) then Exit;
     if not IndexInRange(MapItems, Index) then Exit;
     I := GlobalIndex(MapItems, MapID, Index);
  
positive.code:   FItem: Item;
    I: Integer;
  begin
    Result := FItem;
    Items_Clear_Item(Result);
    if HasEmpty(MapItems) then Exit;
  
negative.code: var
    I, J, A: Integer;
  
    procedure Add(AItem: Item); stdcall;
    var
      A, J: Integer;
    begin
  