# File lib/rbreadline.rb, line 5326
  def rl_maybe_unsave_line()
    if (@_rl_saved_line_for_history)
      # Can't call with `1' because rl_undo_list might point to an undo
      # list from a history entry, as in rl_replace_from_history() below.
      rl_replace_line(@_rl_saved_line_for_history.line, false)
      @rl_undo_list = @_rl_saved_line_for_history.data
      @_rl_saved_line_for_history = nil
      @rl_point = @rl_end  # rl_replace_line sets rl_end
    else
      rl_ding()
    end
    0
  end