apache/spark — pull request #367 by ankurdave (2014-04-09 06:05:09+00:00)
Title: Handle empty partition iterators

Empty edge partitions sometimes appear in the output of zipPartitions for unknown reasons, causing calls to Iterator#next to fail. This PR checks these cases, handles them by returning an empty iterator, and logs an error if this would cause GraphX to drop a corresponding non-empty partition.

Resolves amplab/graphx#52.