Message Title

After updating from Hibernate 5.1 to Hibernate 5.3 we the following exception when deploying our application in Wildfly:

Caused by: java.lang.ClassCastException: org.hibernate.loader.plan.build.internal.spaces.CompositeQuerySpaceImpl cannot be cast to org.hibernate.loader.plan.spi.EntityQuerySpace
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.addJoins(LoadQueryJoinAndFetchProcessor.java:286)
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.renderCollectionJoin(LoadQueryJoinAndFetchProcessor.java:323)
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.renderJoin(LoadQueryJoinAndFetchProcessor.java:170)
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoin(LoadQueryJoinAndFetchProcessor.java:145)
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoins(LoadQueryJoinAndFetchProcessor.java:140)
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoin(LoadQueryJoinAndFetchProcessor.java:146)
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoins(LoadQueryJoinAndFetchProcessor.java:140)
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoin(LoadQueryJoinAndFetchProcessor.java:146)
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoins(LoadQueryJoinAndFetchProcessor.java:140)
	at org.hibernate.loader.plan.exec.internal.LoadQueryJoinAndFetchProcessor.processQuerySpaceJoins(LoadQueryJoinAndFetchProcessor.java:121)
	at org.hibernate.loader.plan.exec.internal.AbstractLoadQueryDetails.generate(AbstractLoadQueryDetails.java:181)
	at org.hibernate.loader.plan.exec.internal.EntityLoadQueryDetails.<init>(EntityLoadQueryDetails.java:85)
	at org.hibernate.loader.plan.exec.internal.BatchingLoadQueryDetailsFactory.makeEntityLoadQueryDetails(BatchingLoadQueryDetailsFactory.java:61)
	at org.hibernate.loader.entity.plan.AbstractLoadPlanBasedEntityLoader.<init>(AbstractLoadPlanBasedEntityLoader.java:95)
	at org.hibernate.loader.entity.plan.EntityLoader.<init>(EntityLoader.java:125)
	at org.hibernate.loader.entity.plan.EntityLoader.<init>(EntityLoader.java:38)
	at org.hibernate.loader.entity.plan.EntityLoader$Builder.byUniqueKey(EntityLoader.java:90)
	at org.hibernate.loader.entity.plan.EntityLoader$Builder.byPrimaryKey(EntityLoader.java:83)
	at org.hibernate.loader.entity.plan.AbstractBatchingEntityLoaderBuilder.buildNonBatchingLoader(AbstractBatchingEntityLoaderBuilder.java:30)
	at org.hibernate.loader.entity.BatchingEntityLoaderBuilder.buildLoader(BatchingEntityLoaderBuilder.java:59)
	at org.hibernate.persister.entity.AbstractEntityPersister.createEntityLoader(AbstractEntityPersister.java:2494)
	at org.hibernate.persister.entity.AbstractEntityPersister.createEntityLoader(AbstractEntityPersister.java:2516)
	at org.hibernate.persister.entity.AbstractEntityPersister.createLoaders(AbstractEntityPersister.java:4248)
	at org.hibernate.persister.entity.AbstractEntityPersister.postInstantiate(AbstractEntityPersister.java:4222)
	at org.hibernate.metamodel.internal.MetamodelImpl.initialize(MetamodelImpl.java:257)
	at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:294)
	at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:462)
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:938)
	... 34 more

After some investigation we found out that this is caused by the combination of using the Joined strategy for inheritence and using the same embedded entity multiple times in entities in the inheritance hierarchy. A test case using the Hibernate Test Case template can be found here: https://github.com/jpdigital/hibernate-test-case-templates/tree/master/orm/hibernate-orm-5 (in the JPAUnitTestCase).

I executed the test with different versions of Hibernate. 5.1 works, starting with 5.2 the expectation is thrown.