From 6880f73ae0ad05515b217c799dac3c05c86fbc9d Mon Sep 17 00:00:00 2001
From: Andrea Boriero <andrea@hibernate.org>
Date: Wed, 13 Nov 2024 10:19:46 +0100
Subject: [PATCH] HHH-18842 CollectionType.replace() breaks if target is
 PersistentCollection, but not instance of Collection

---
 .../collection/spi/PersistentArrayHolder.java |  4 +++
 .../hibernate/engine/internal/Cascade.java    | 14 +++++++++--
 .../org/hibernate/type/CollectionType.java    | 25 +++++++++++++++++--
 3 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/collection/spi/PersistentArrayHolder.java b/hibernate-core/src/main/java/org/hibernate/collection/spi/PersistentArrayHolder.java
index 4ade676b92..426ca5b88d 100644
--- a/hibernate-core/src/main/java/org/hibernate/collection/spi/PersistentArrayHolder.java
+++ b/hibernate-core/src/main/java/org/hibernate/collection/spi/PersistentArrayHolder.java
@@ -7,6 +7,7 @@ package org.hibernate.collection.spi;
 import java.io.Serializable;
 import java.lang.reflect.Array;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
@@ -92,6 +93,9 @@ public class PersistentArrayHolder<E> extends AbstractPersistentCollection<E> {
 	public Collection getOrphans(Serializable snapshot, String entityName) throws HibernateException {
 		final Object[] sn = (Object[]) snapshot;
 		final Object[] arr = (Object[]) array;
+		if ( arr.length == 0 ) {
+			return Arrays.asList( sn );
+		}
 		final ArrayList result = new ArrayList();
 		Collections.addAll( result, sn );
 		for ( int i=0; i<sn.length; i++ ) {
diff --git a/hibernate-core/src/main/java/org/hibernate/engine/internal/Cascade.java b/hibernate-core/src/main/java/org/hibernate/engine/internal/Cascade.java
index 2f5524c7ad..56ffcd6936 100644
--- a/hibernate-core/src/main/java/org/hibernate/engine/internal/Cascade.java
+++ b/hibernate-core/src/main/java/org/hibernate/engine/internal/Cascade.java
@@ -601,10 +601,20 @@ public final class Cascade {
 			}
 		}
 
+		// a newly instantiated collection can't have orphans
+		final PersistentCollection<?> persistentCollection;
+		if ( child instanceof PersistentCollection<?> pc ) {
+			persistentCollection = pc;
+		}
+		else {
+			persistentCollection = eventSource.getPersistenceContext()
+					.getCollectionHolder( child );
+		}
+
 		final boolean deleteOrphans = style.hasOrphanDelete()
 				&& action.deleteOrphans()
 				&& elemType instanceof EntityType
-				&& child instanceof PersistentCollection<?> persistentCollection
+				&& persistentCollection != null
 				// a newly instantiated collection can't have orphans
 				&& !persistentCollection.isNewlyInstantiated();
 
@@ -617,7 +627,7 @@ public final class Cascade {
 			// 1. newly instantiated collections
 			// 2. arrays (we can't track orphans for detached arrays)
 			final String entityName = collectionType.getAssociatedEntityName( eventSource.getFactory() );
-			deleteOrphans( eventSource, entityName, (PersistentCollection<?>) child );
+			deleteOrphans( eventSource, entityName, persistentCollection );
 
 			if ( traceEnabled ) {
 				LOG.tracev( "Done deleting orphans for collection: {0}", collectionType.getRole() );
diff --git a/hibernate-core/src/main/java/org/hibernate/type/CollectionType.java b/hibernate-core/src/main/java/org/hibernate/type/CollectionType.java
index 5ddeeae38a..0e7409fb01 100644
--- a/hibernate-core/src/main/java/org/hibernate/type/CollectionType.java
+++ b/hibernate-core/src/main/java/org/hibernate/type/CollectionType.java
@@ -24,6 +24,7 @@ import org.hibernate.Incubating;
 import org.hibernate.Internal;
 import org.hibernate.MappingException;
 import org.hibernate.collection.spi.AbstractPersistentCollection;
+import org.hibernate.collection.spi.PersistentArrayHolder;
 import org.hibernate.collection.spi.PersistentCollection;
 import org.hibernate.engine.spi.CollectionEntry;
 import org.hibernate.engine.spi.CollectionKey;
@@ -634,11 +635,31 @@ public abstract class CollectionType extends AbstractType implements Association
 			if ( target == null ) {
 				return null;
 			}
-			if ( target instanceof PersistentCollection ) {
-				final Collection collection = (Collection) target;
+			if ( target instanceof Collection<?> collection ) {
 				collection.clear();
 				return collection;
 			}
+			else if ( target instanceof Map<?,?> map ) {
+				map.clear();
+				return map;
+			}
+			else {
+				final PersistenceContext persistenceContext = session.getPersistenceContext();
+				final PersistentCollection<?> collectionHolder = persistenceContext
+						.getCollectionHolder( target );
+				if ( collectionHolder != null ) {
+					if ( collectionHolder instanceof PersistentArrayHolder<?> persistentArrayHolder ) {
+						persistenceContext.removeCollectionHolder( target );
+						persistentArrayHolder.beginRead();
+						persistentArrayHolder.injectLoadedState( persistenceContext.getCollectionEntry( collectionHolder ).getLoadedPersister().getAttributeMapping(), null );
+						persistentArrayHolder.endRead();
+						persistentArrayHolder.dirty();
+						persistenceContext.addCollectionHolder( collectionHolder );
+						return persistentArrayHolder.getArray();
+					}
+				}
+			}
+
 			return null;
 		}
 		if ( !Hibernate.isInitialized( original ) ) {