facebook/phabricator — pull request #507 by billywatson (2014-02-12 17:31:53+00:00)
Title: fix data migration issues when migrating from really old databases

We had an issue when migrating our 8-month old database. Apparently, there were some revisions that had reviewers that were missing the src_type (or type) in their data column. These two guard statements fixed that issue for us.