# File lib/sup/modes/thread-index-mode.rb, line 743
  def update_text_for_line l
    return unless l # not sure why this happens, but it does, occasionally
    
    need_update = false

    @mutex.synchronize do
      @size_widgets[l] = size_widget_for_thread @threads[l]

      ## if the widget size has increased, we need to redraw everyone
      need_update = @size_widgets[l].size > @size_widget_width
    end

    if need_update
      update
    else
      @text[l] = text_for_thread_at l
      buffer.mark_dirty if buffer
    end
  end