[css3-books][css3-gcpm] multi-line leaders

I have another leader issue. Currently, the spec presecribes
multi-line leaders in certain cases. One of the examples has this
rendering:

  Douglas Adams...
  ..............42

The normative text is:

  If the presence of a minimum length leader at the end of a line
  results in subsequent content being moved to the next line, the
  leader will also appear at the beginning of the next line.

  http://books.spec.whatwg.org/#leaders

However, I'm unsure if multi-line leaders should be prescribed. Do
multi-line leders exist in any typographical tradition? Samplings from
three semi-random publications indicate that leaders only appear on
a single line:

  http://www.wiumlie.no/2013/whatwg/books/1.png
  http://www.wiumlie.no/2013/whatwg/books/2.png
  http://www.wiumlie.no/2013/whatwg/books/3.png

If we decide that multi-line leaders should not be supported, one quick
fix is probably to say:

  If the presence of a minimum length leader at the end of a line
  results in subsequent content being moved to the next line, the
  leader will only appear at the beginning of the next line.

Which should result in this rendering:

  Douglas Adams
  ..............42

which may not be right either; none of the examples have a leader at
the start of a line. An alternative may be:

  Douglas 
  Adams.........42

But I'm unsure if it looks better. 

Feedback welcome.

-h&kon
              Håkon Wium Lie                          CTO °þe®ª
howcome@opera.com                  http://people.opera.com/howcome