NullReferenceException when many-to-many relation with the same key name as backreference

Hello.

There is a problem with Envers when you have a many-to-many relation between two entities and one of them has another many-to-one relation with the same key name. This works just fine in nHibernate, but when you enable Envers it crashes in NHibernate.Envers.Synchronization.Work.FakeBidirectionalRelationWorkUnit.FakeRelationChange.GenerateData method.