Comment 40 for bug 861664

(In reply to Dave Townsend (:Mossop) from comment #38)
> The testcase from bug 664833 already checks installing an update when the DB
> schema and app version changes. The only thing missing was to make the
> cached manifest have a necessary property missing so I updated the test to
> do that. Without this fix the test fails in the same way that I've been
> seeing in this bug.

Forgot to add, the testcase here is good and I think an accurate test for this, however it suffers from the same problem that much of our automated tests for updates do, it doesn't actually test moving from one version of Firefox to another in reality. So we certainly want a litmus test for this scenario.