HHH-13129 : Cascaded merge fails for detached bytecode-enhanced entity with uninitialized ToOne

hibernate-core/src/main/java/org/hibernate/engine/internal/Cascade.java

@@ -12,12 +12,10 @@ import java.util.HashSet;
 import java.util.Iterator;
 
 import org.hibernate.HibernateException;
-import org.hibernate.bytecode.enhance.spi.LazyPropertyInitializer;
 import org.hibernate.bytecode.enhance.spi.interceptor.LazyAttributeLoadingInterceptor;
 import org.hibernate.collection.spi.PersistentCollection;
 import org.hibernate.engine.spi.CascadeStyle;
 import org.hibernate.engine.spi.CascadingAction;
-import org.hibernate.engine.spi.CascadingActions;
 import org.hibernate.engine.spi.CollectionEntry;
 import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.Status;
@@ -102,25 +100,46 @@ public final class Cascade {
 					final Object child;
 					if ( isUninitializedProperty  ) {
 						// parent is a bytecode enhanced entity.
-						// cascading to an uninitialized, lazy value.
-						if ( types[ i ].isCollectionType() ) {
-							// The collection does not need to be loaded from the DB.
-							// CollectionType#resolve will return an uninitialized PersistentCollection.
-							// The action will initialize the collection later, if necessary.
-							child = types[ i ].resolve( LazyPropertyInitializer.UNFETCHED_PROPERTY, eventSource, parent );
-							// TODO: it would be nice to be able to set the attribute in parent using
-							// persister.setPropertyValue( parent, i, child ).
-							// Unfortunately, that would cause the uninitialized collection to be
-							// loaded from the DB.
+						// Cascade to an uninitialized, lazy value only if
+						// parent is managed in the PersistenceContext.
+						// If parent is a detached entity being merged,
+						// then parent will not be in the PersistencContext
+						// (so lazy attributes must not be initialized).
+						if ( eventSource.getPersistenceContext().getEntry( parent ) == null ) {
+							// parent was not in the PersistenceContext
+							continue;
 						}
-						else if ( action.performOnLazyProperty() ) {
-							// The (non-collection) attribute needs to be initialized so that
-							// the action can be performed on the initialized attribute.
-							LazyAttributeLoadingInterceptor interceptor = persister.getInstrumentationMetadata().extractInterceptor( parent );
+						if ( types[ i ].isCollectionType() ) {
+							// CollectionType#getCollection gets the PersistentCollection
+							// that corresponds to the uninitialized collection from the
+							// PersistenceContext. If not present, an uninitialized
+							// PersistentCollection will be added to the PersistenceContext.
+							// The action may initialize it later, if necessary.
+							// This needs to be done even when action.performOnLazyProperty() returns false.
+							final CollectionType collectionType = (CollectionType) types[i];
+							child = collectionType.getCollection(
+									collectionType.getKeyOfOwner( parent, eventSource ),
+									eventSource,
+									parent,
+									null
+							);
+						}
+						else if ( types[ i ].isComponentType() ) {
+							// Hibernate does not support lazy embeddables, so this shouldn't happen.
+							throw new UnsupportedOperationException(
+									"Lazy components are not supported."
+							);
+						}
+						else if ( action.performOnLazyProperty() && types[ i ].isEntityType() ) {
+							// Only need to initialize a lazy entity attribute when action.performOnLazyProperty()
+							// returns true.
+							LazyAttributeLoadingInterceptor interceptor = persister.getInstrumentationMetadata()
+									.extractInterceptor( parent );
 							child = interceptor.fetchAttribute( parent, propertyName );
+
 						}
 						else {
-							// Nothing to do, so just skip cascading to this lazy (non-collection) attribute.
+							// Nothing to do, so just skip cascading to this lazy attribute.
 							continue;
 						}
 					}

hibernate-core/src/main/java/org/hibernate/event/internal/DefaultDeleteEventListener.java

@@ -131,6 +131,7 @@ public class DefaultDeleteEventListener implements DeleteEventListener,	Callback
 					persister,
 					false
 			);
+			persister.afterReassociate( entity, source );
 		}
 		else {
 			LOG.trace( "Deleting a persistent instance" );