bool Item_param::add_as_clone(THD *thd)
{
  LEX *lex= thd->lex;
  uint master_pos= pos_in_query + lex->clone_spec_offset;
  List_iterator_fast<Item_param> it(lex->param_list);
  Item_param *master_param;
  while ((master_param = it++))
  {
    if (master_pos == master_param->pos_in_query)
      return master_param->register_clone(this);
  }
  DBUG_ASSERT(false);
  return false;
}
bool Item_param::add_as_clone(THD *thd)
{
  LEX *lex= thd->lex;
  uint master_pos= pos_in_query + lex->clone_spec_offset;
  List_iterator_fast<Item_param> it(lex->param_list);
  Item_param *master_param;
  while ((master_param = it++))
  {
    if (master_pos == master_param->pos_in_query)
      return master_param->register_clone(this);
  }
  DBUG_ASSERT(false);
  return false;
}