Jones ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiYmNmZWQxNzA1... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16258?atlOrigin=eyJpIjoiYmNmZW... ) HHH-16258 ( https://hibernate.atlassian.net/browse/HHH-16258?atlOrigin=eyJpIjoiYmNmZW... ) NPE with SubselectFetch and inheritance ( https://hibernate.atlassian.net/browse/HHH-16258?atlOrigin=eyJpIjoiYmNmZW... ) Issue Type: Bug Affects Versions: 6.1.7, 6.2.0.CR3 Assignee: Unassigned Components: hibernate-core Created: 06/Mar/2023 23:42 PM Priority: Critical Reporter: Jones ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) Given: * Single table inheritance using discriminator * One child entity has an OneToMany relationship to a certain entity of type A using FetchMode. *SUBSELECT* * Another child entity has another OneToMany relationship to a certain entity of type B also using FetchMode. *SUBSELECT* When * Querying both entities and initializing the first child relationship Then * A NPE happens when hibernate wrongly tries to load the 2nd child relationship with entity of type A, which mapping doesn’t exist for the second child type. @Entity @Table(name = "MY_ENTITY" ) @DiscriminatorColumn(name = "DISC_COL" , discriminatorType = DiscriminatorType.INTEGER) @DiscriminatorValue( "0" ) public class ParentEntity { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "ID" ) Integer id; } @Entity @DiscriminatorValue( "1" ) public class MyEntityWithAnotherEntities extends ParentEntity { @OneToMany(mappedBy = "myEntity" ) @Fetch(FetchMode.SUBSELECT) List<AnotherEntity> anotherEntities = new ArrayList<>(); } @Entity @DiscriminatorValue( "2" ) public class MyEntityWithSomeOtherEntities extends ParentEntity { @OneToMany(mappedBy = "myEntity" ) @Fetch(FetchMode.SUBSELECT) List<SomeOtherEntity> someOtherEntitiesEntities = new ArrayList<>(); } @Test public void hhhXXXXTest() throws Exception { // BaseCoreFunctionalTestCase automatically creates the SessionFactory and // provides the Session. AnotherEntity anotherEntity1 = new AnotherEntity(); MyEntityWithAnotherEntities child1 = new MyEntityWithAnotherEntities(); MyEntityWithSomeOtherEntities child2 = new MyEntityWithSomeOtherEntities(); try (Session s = openSession()) { Transaction tx = s.beginTransaction(); child1.anotherEntities.add(anotherEntity1); anotherEntity1.myEntity = child1; s.persist(child1); s.persist(child2); s.persist(anotherEntity1); tx.commit(); } try (Session s = openSession()) { Transaction tx = s.beginTransaction(); Query<ParentEntity> query = s.createQuery( "from ParentEntity e order by e.id" , ParentEntity.class); List<ParentEntity> entities = query.list(); assertThat(entities).hasSize(2); assertThat(entities.get(0)).isInstanceOf(MyEntityWithAnotherEntities.class); // initialize anotherEntities which uses subselect batch fetch which will lead // to the exception assertThat(((MyEntityWithAnotherEntities) entities.get(0)).anotherEntities).isNotEmpty(); tx.commit(); } } java.lang.NullPointerException: Cannot invoke "org.hibernate.collection.spi.PersistentCollection.beginRead()" because "containedCollection" is null at org.hibernate.loader.ast.internal.CollectionLoaderSubSelectFetch.load(CollectionLoaderSubSelectFetch.java:110) at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:716) at org.hibernate.event.internal.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:75) at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:127) at org.hibernate.internal.SessionImpl.initializeCollection(SessionImpl.java:1697) at org.hibernate.collection.spi.AbstractPersistentCollection.lambda$initialize$3(AbstractPersistentCollection.java:617) at org.hibernate.collection.spi.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:265) at org.hibernate.collection.spi.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:615) at org.hibernate.collection.spi.AbstractPersistentCollection.read(AbstractPersistentCollection.java:136) at org.hibernate.collection.spi.AbstractPersistentCollection.lambda$readSize$0(AbstractPersistentCollection.java:163) at org.hibernate.collection.spi.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:265) at org.hibernate.collection.spi.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:148) at org.hibernate.collection.spi.PersistentBag.isEmpty(PersistentBag.java:359) at org.assertj.core.util.IterableUtil.isNullOrEmpty(IterableUtil.java:37) at org.assertj.core.internal.Iterables.assertNotEmpty(Iterables.java:188) at org.assertj.core.api.AbstractIterableAssert.isNotEmpty(AbstractIterableAssert.java:142) at org.hibernate.bugs.ORMUnitTestCase.hhh16254Test(ORMUnitTestCase.java:88) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:568) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56) at org.hibernate.testing.junit4.ExtendedFrameworkMethod.invokeExplosively(ExtendedFrameworkMethod.java:45) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27) at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:299) at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:293) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at java.base/java.lang.Thread.run(Thread.java:833) The issue happens because SubselectFetch. StandardRegistrationHandler.addKey method wrongly registers a key even for the child entity which doesn’t have that collection mapped. This works fine on latest hibernate 5 series. It doesn’t work in any hibernate 6 series. Failing test scenario to be attached ( https://hibernate.atlassian.net/browse/HHH-16258#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16258#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100217- sha1:45db922 )