Handle parse errors during diff migration.
Review Request #5485 — Created Feb. 16, 2014 and submitted — Latest diff uploaded
Handle parse errors during diff migration.
The new diff size column would cause migrations for old diff data. In the case
where a very old review request has un-migrated data which doesn't parse
correctly (from back when you could attach a bogus diff to a review request),
it would cause an un-caught exception. This change handles DiffParseErrors in
the recalculate_line_counts method.
Ran unit tests.