Created attachment 789255 [details]
Exception stack trace

Description of problem:

When KieSession is serialized, a NPE is thrown in org.drools.core.marshalling.impl.ProtobufOutputMarshaller.writeRIANodeMemory(ProtobufOutputMarshaller.java:377).

Please see the attached stack trace for details.

I am not sure what exactly causes the NPE to be thrown, it probably depends on using some user defined facts (if I removed them, the NPE did not occur).

Please see the reproducer from the pull request which will be attached shortly.


Version-Release number of selected component (if applicable):

Drools 6.0.0-SNAPSHOT

How reproducible:

Please run JpaPersistentStatefulSessionTest#testMoreComplexRulesSerialization() test from the attached pull request.