We now consider a transactional rollback that returns an empty EXEC result as rollback for the CAS (compare-and-set) operation. Previously, we checked only that the response of EXEC is not null. A rollback returns an empty list which was previously considered a successful CAS operation.
The code for CAS is now extracted to CompareAndSet and is reused from RedisAtomic implementations.
Original Pull Request: #349
191244b1a4