rescue_from and assert_raise

Since commit 5e3517ea7b9fbd460f772bffc9212d882011f2bc, rescue_from is
now being handled in tests. I've been using rescue_from to handle
custom exceptions and testing that those exceptions are raised in
functional tests with assert_raise. This no longer works now. What's
the proper way to test this now?

Anyone have any input on this?