HHH-17668 NullPointerException when refreshing bytecode-enhanced entity from second-level cache

Author: dreab8

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

@@ -64,21 +64,39 @@ public void onRefresh(RefreshEvent event, RefreshContext refreshedAlready) {
 		final Object object = event.getObject();
 		if ( persistenceContext.reassociateIfUninitializedProxy( object ) ) {
 			final boolean isTransient = isTransient( event, source, object );
+			// If refreshAlready is not empty then the refresh is the result of a
+			// cascade refresh and the refresh of the parent will take care of initializing the lazy
+			// entity and setting the correct lock on it, this is needed only when the refresh is called directly on a lazy entity
+			if ( refreshedAlready.isEmpty() ) {
+				final LazyInitializer lazyInitializer = HibernateProxy.extractLazyInitializer( object );
+				final EntityPersister persister;
+				if ( lazyInitializer != null ) {
+					persister = source.getEntityPersister( lazyInitializer.getEntityName(), object );
+				}
+				else if ( !isTransient ) {
+					final EntityEntry entry = persistenceContext.getEntry( object );
+					persister = entry.getPersister();
+				}
+				else {
+					persister = source.getEntityPersister( source.guessEntityName( object ), object );
+				}
 
-			final LazyInitializer lazyInitializer = HibernateProxy.extractLazyInitializer( object );
-			final EntityPersister persister = source.getEntityPersister( lazyInitializer.getEntityName(), object );
-			refresh(
-					event,
-					null,
-					source,
-					persister,
-					lazyInitializer,
-					null,
-					persister.getIdentifier( object, event.getSession() ),
-					persistenceContext
-			);
+				refresh(
+						event,
+						null,
+						source,
+						persister,
+						lazyInitializer,
+						null,
+						persister.getIdentifier( object, event.getSession() ),
+						persistenceContext
+				);
+				if ( lazyInitializer != null ) {
+					refreshedAlready.add( lazyInitializer.getImplementation() );
+				}
+			}
 
-			if ( isTransient  ) {
+			if ( isTransient ) {
 				source.setReadOnly( object, source.isDefaultReadOnly() );
 			}
 		}

hibernate-core/src/main/java/org/hibernate/event/spi/RefreshContext.java

@@ -19,6 +19,10 @@ public interface RefreshContext {
 
 	boolean add(Object entity);
 
+	default boolean isEmpty() {
+		return false;
+	}
+
 	static RefreshContext create() {
 		// use extension to avoid creating
 		// a useless wrapper object
@@ -32,6 +36,11 @@ class Impl extends IdentityHashMap<Object,Object>
 			public boolean add(Object entity) {
 				return put(entity,entity)==null;
 			}
+
+			@Override
+			public boolean isEmpty() {
+				return size() == 0;
+			}
 		}
 		return new Impl();
 	}