# File lib/rbreadline.rb, line 5265
  def _rl_current_display_line()
    # Find out whether or not there might be invisible characters in the
    #   editing buffer.
    if (@rl_display_prompt == @rl_prompt)
      nleft = @_rl_last_c_pos - @_rl_screenwidth - @rl_visible_prompt_length
    else
      nleft = @_rl_last_c_pos - @_rl_screenwidth
    end

    if (nleft > 0)
      ret = 1 + nleft / @_rl_screenwidth
    else
      ret = 0
    end

    ret
  end