Fix division-by-zero bug.
Fix division-by-zero bug.

This fixes the hanging described in #59, but the query still returns 0 results
and the partition complains about not finding indexers. Investigating now...

mavam/vast,vast-io/vast,mavam/vast,pmos69/vast,pmos69/vast,pmos69/vast,mavam/vast,vast-io/vast,vast-io/vast,mavam/vast,vast-io/vast,pmos69/vast,vast-io/vast