# File lib/sup/modes/line-cursor-mode.rb, line 111
  def cursor_up
    return false unless @curpos > @cursor_top
    if @curpos == topline
      old_topline = topline
      page_up
      set_cursor_pos [old_topline - 1, topline].max
    else
      @curpos -= 1
      unless buffer.dirty?
        draw_line @curpos + 1
        draw_line @curpos
        set_status
        buffer.commit
      end
    end
    true
  end