I went ahead and pushed this into 9.2 and 9.1. It did not apply at all
to 9.0, though, as there evidently was some refactoring affecting
LockReassignCurrentOwner() between 9.0 and 9.1. We could possibly have
applied some additional patches to 9.0, but I think that would be
stretching the argument that this is well-tested code.
regards, tom lane