void Item_type_holder::get_full_info(Item *item)

{

  if (Item_type_holder::real_type_handler() == &type_handler_enum ||

      Item_type_holder::real_type_handler() == &type_handler_set)

  {

    if (item->type() == Item::SUM_FUNC_ITEM &&

        (((Item_sum*)item)->sum_func() == Item_sum::MAX_FUNC ||

         ((Item_sum*)item)->sum_func() == Item_sum::MIN_FUNC))

      item = ((Item_sum*)item)->get_arg(0);

    /*

      We can have enum/set type after merging only if we have one enum|set

      field (or MIN|MAX(enum|set field)) and number of NULL fields

    */

    DBUG_ASSERT((enum_set_typelib &&

                 item->real_type_handler() == &type_handler_null) ||

                (!enum_set_typelib &&

                 item->real_item()->type() == Item::FIELD_ITEM &&

                 (item->real_type_handler() == &type_handler_enum ||

                  item->real_type_handler() == &type_handler_set) &&

                 ((Field_enum*)((Item_field *) item->real_item())->field)->typelib;

    if (!enum_set_typelib)

    {

      enum_set_typelib= ((Field_enum*)((Item_field *) item->real_item())->field)

    }

  }

}

virtual TYPELIB *Field::get_typelib() const;

virtual TYPELIB *Item::get_typelib() const;