Hello,
we found another query bug:
SELECT a FROM ArtifactImpl a LEFT OUTER JOIN a.tcSignal s WHERE a.startStep.stepNumber <= 2 AND a.endStep.stepNumber >= 0 AND (s.name IN ('In1') OR a.tcSignal IS NULL)
With 2.7.6_b6 we get the expected three result objects.
But with 2.8.0 we get only two result objects, the ArtifactImpl is missed whose attribute tcSignal is Null.