HHH-18553 handle case where managed entity was already removed

just short-circuit and abort the remove()

Signed-off-by: Gavin King <gavin@hibernate.org>

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

@@ -176,10 +176,10 @@ public class DefaultDeleteEventListener implements DeleteEventListener,	Callback
 		}
 
 		final EntityKey key = source.generateEntityKey( id, persister);
-		final Object version = persister.getVersion(entity);
+		final Object version = persister.getVersion( entity );
 
 //		persistenceContext.checkUniqueness( key, entity );
-		flushAndEvictExistingEntity( key, version, persister, source );
+		if ( !flushAndEvictExistingEntity( key, version, persister, source ) ) {
 
 			new OnUpdateVisitor( source, id, entity ).process( entity, persister );
 
@@ -195,26 +195,36 @@ public class DefaultDeleteEventListener implements DeleteEventListener,	Callback
 					persister,
 					false
 			);
-		persister.afterReassociate(entity, source);
+			persister.afterReassociate( entity, source );
 
 			delete( event, transientEntities, source, entity, persister, id, version, entityEntry );
 		}
+	}
 
 	/**
 	 * Since Hibernate 7, if a detached instance is passed to remove(),
 	 * and if there is already an existing managed entity with the same
 	 * id, flush and evict it, after checking that the versions match.
+	 *
+	 * @return true if the managed entity was already deleted
 	 */
-	private static void flushAndEvictExistingEntity(
+	private static boolean flushAndEvictExistingEntity(
 			EntityKey key, Object version, EntityPersister persister, EventSource source) {
-		final Object existingEntity = source.getPersistenceContextInternal().getEntity( key );
+		final PersistenceContext persistenceContext = source.getPersistenceContextInternal();
+		final Object existingEntity = persistenceContext.getEntity( key );
 		if ( existingEntity != null ) {
+			if ( persistenceContext.getEntry( existingEntity ).getStatus().isDeletedOrGone() ) {
+				// already deleted, no work to do
+				return true;
+			}
+			else {
 				LOG.flushAndEvictOnRemove( key.getEntityName() );
 				source.flush();
 				if ( !persister.isVersioned()
 						|| persister.getVersionType()
 								.isEqual( version, persister.getVersion( existingEntity ) ) ) {
 					source.evict( existingEntity );
+					return false;
 				}
 				else {
 					throw new StaleObjectStateException( key.getEntityName(), key.getIdentifier(),
@@ -222,6 +232,10 @@ public class DefaultDeleteEventListener implements DeleteEventListener,	Callback
 				}
 			}
 		}
+		else {
+			return false;
+		}
+	}
 
 	private void deletePersistentInstance(
 			DeleteEvent event,

hibernate-core/src/test/java/org/hibernate/orm/test/deletedetached/DeleteDetachedTest.java

@@ -56,6 +56,20 @@ public class DeleteDetachedTest {
 		});
 		scope.inTransaction(s -> assertNotNull(s.find(Thing.class, thing.id)));
 	}
+	@Test void testAlreadyRemoved(SessionFactoryScope scope) {
+		Thing thing = new Thing();
+		thing.stuff = "Some stuff about the thing";
+		scope.inTransaction(s -> s.persist(thing));
+		scope.inTransaction(s -> {
+			Thing otherThing = s.find(Thing.class, thing.id);
+			assertNotNull(otherThing);
+			s.remove(otherThing);
+			s.remove(thing);
+			assertFalse(s.contains(thing));
+			assertFalse(s.contains(otherThing));
+		});
+		scope.inTransaction(s -> assertNull(s.find(Thing.class, thing.id)));
+	}
 	@Entity
 	static class Thing {
 		@GeneratedValue @Id long id;