# File lib/rbreadline.rb, line 7892
  def rl_modifying(start, _end)
    if (start > _end)
      start,_end = _end,start
    end

    if (start != _end)
      temp = rl_copy_text(start, _end)
      rl_begin_undo_group()
      rl_add_undo(UNDO_DELETE, start, _end, temp)
      rl_add_undo(UNDO_INSERT, start, _end, nil)
      rl_end_undo_group()
    end
    0
  end