akka/akka — pull request #1645 by patriknw (2013-08-16 10:08:22+00:00)
Title: =clu #3517 Guard against wrong random selection

* When all weights in the map are zero total became 0, which is not
valid in random pick. Treat this special case as empty WeightedRoutees, i.e.
no availble targets and routing to deadLetters.