Message Title

On the lock, the natural id reattachment must use a database snapshot, since the natural id is mutable. Your B entity has 2 natural ids: one using ManyToOnType and the other IntegerType. The reattachment uses this stack:

	ManyToOneType.hydrate(ResultSet, String[], SessionImplementor, Object) line: 190	
	SingleTableEntityPersister(AbstractEntityPersister).getDatabaseSnapshot(Serializable, SessionImplementor) line: 1534	
	StatefulPersistenceContext.getDatabaseSnapshot(Serializable, EntityPersister) line: 316	
	SingleTableEntityPersister(AbstractEntityPersister).handleNaturalIdReattachment(Object, SessionImplementor) line: 4248	
	SingleTableEntityPersister(AbstractEntityPersister).afterReassociate(Object, SessionImplementor) line: 4228	
	DefaultLockEventListener(AbstractReassociateEventListener).reassociate(AbstractEvent, Object, Serializable, EntityPersister) line: 100	
	DefaultLockEventListener.onLock(LockEvent) line: 95	
	SessionImpl.fireLock(LockEvent) line: 819	
	SessionImpl.fireLock(Object, LockOptions) line: 812	
	SessionImpl.access$11(SessionImpl, Object, LockOptions) line: 811	
	SessionImpl$LockRequestImpl.lock(Object) line: 2438	
	...

ManyToOneType#hydrate does not return the actual A entity – instead, it returns the FK Long value. The hydrated values are later used by the following stack. ManyToOneType#disassemble is called, assuming the value is the A entity. It fails when the Long is there instead.

	DirectPropertyAccessor$DirectGetter.get(Object) line: 62	
	PojoEntityTuplizer(AbstractEntityTuplizer).getIdentifier(Object, SessionImplementor) line: 345	
	SingleTableEntityPersister(AbstractEntityPersister).getIdentifier(Object, SessionImplementor) line: 4547	
	SingleTableEntityPersister(AbstractEntityPersister).isTransient(Object, SessionImplementor) line: 4269	
	ForeignKeys.isTransient(String, Object, Boolean, SessionImplementor) line: 243	
	ForeignKeys.getEntityIdentifierIfNotUnsaved(String, Object, SessionImplementor) line: 293	
	ManyToOneType.disassemble(Object, SessionImplementor, Object) line: 247	
	NaturalIdCacheKey.<init>(Object[], EntityPersister, SessionImplementor) line: 84	
	StatefulPersistenceContext$1.removeSharedNaturalIdCrossReference(EntityPersister, Serializable, Object[]) line: 1825	
	SingleTableEntityPersister(AbstractEntityPersister).handleNaturalIdReattachment(Object, SessionImplementor) line: 4256	
	SingleTableEntityPersister(AbstractEntityPersister).afterReassociate(Object, SessionImplementor) line: 4228	
	DefaultLockEventListener(AbstractReassociateEventListener).reassociate(AbstractEvent, Object, Serializable, EntityPersister) line: 100	
	DefaultLockEventListener.onLock(LockEvent) line: 95	
	SessionImpl.fireLock(LockEvent) line: 819	
	SessionImpl.fireLock(Object, LockOptions) line: 812	
	SessionImpl.access$11(SessionImpl, Object, LockOptions) line: 811	
	SessionImpl$LockRequestImpl.lock(Object) line: 2438	
	...