NullPointerException merging entity with a lazy to-many association in Hibernate

Environment

• Red Hat JBoss Enterprise Application Platform (EAP) 7
• Hibernate 5

Issue

• Entity has a lazy to-many association which is un-initialized

• Encountering a NullPointerException when merging the entity

  ... java.lang.NullPointerException
      at org.hibernate.type.EntityType.replace(EntityType.java:313)
      at org.hibernate.collection.internal.AbstractPersistentCollection$AbstractValueDelayedOperation.getReplacement(AbstractPersistentCollection.java:1164)
      at org.hibernate.collection.internal.AbstractPersistentCollection$AbstractValueDelayedOperation.replace(AbstractPersistentCollection.java:1159)
      at org.hibernate.collection.internal.AbstractPersistentCollection.replaceQueuedOperationValues(AbstractPersistentCollection.java:489)
      at org.hibernate.type.CollectionType.replace(CollectionType.java:652)
      at org.hibernate.type.TypeHelper.replace(TypeHelper.java:177)
      at org.hibernate.event.internal.DefaultMergeEventListener.copyValues(DefaultMergeEventListener.java:393)
      at org.hibernate.event.internal.DefaultMergeEventListener.entityIsDetached(DefaultMergeEventListener.java:327)
      at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:169)
      at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:68)
      at org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:843)
      at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:825)
      at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:830)
      at org.hibernate.jpa.spi.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:1161)
      at org.jboss.as.jpa.container.AbstractEntityManager.merge(AbstractEntityManager.java:565)
  

Resolution

This issue will be addressed in a future release¹.

Root Cause

This is a known defect (Content from hibernate.atlassian.net is not included.HHH-11209).

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