[rules-users] npe in LogicalRetractCallback when using jpa persistence

Hi guys, I think I've found a problem in the TruthMaintenanceSystem and would like to know if its a real bug or if I've made some mistake... I'm using the latest drools and drools flow snapshot with jpa persistence. When I'm retracting a fact from the knowledge session (which causes logical retraction), the session can't be persisted any more. During retraction a LogicalRetractCallback is instantiated using this constructor: public LogicalRetractCallback(final TruthMaintenanceSystem tms, final LogicalDependency node, final Set set, final InternalFactHandle handle, final PropagationContext context, final Activation activation) { this.tms = tms; this.node = node; this.set = set; this.handle = handle; this.context = context; } As you can see an activation object can be passed (and actually is passed) to the constructor, but is never used. Retraction works though. The problem occurs when the knowledge session is persisted, because LogicalRetractCallback.write assumes that activation is not null, which leads to this npe: Caused by: java.lang.NullPointerException org.drools.common.TruthMaintenanceSystem$LogicalRetractCallback.write(TruthMaintenanceSystem.java:251) org.drools.marshalling.impl.OutputMarshaller.writeActionQueue(OutputMarshaller.java:201) It would be cool if anyone could have a look at this... Thanks, chris