Fixes cascading orphan delete on versioned entity

src/NHibernate.Test/Async/NHSpecificTest/GH3325/Fixture.cs

@@ -0,0 +1,68 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by AsyncGenerator.
+//
+//     Changes to this file may cause incorrect behavior and will be lost if
+//     the code is regenerated.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+
+using System;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH3325
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class FixtureAsync : BugTestCase
+	{
+		protected override void OnSetUp()
+		{
+			Sfi.Statistics.IsStatisticsEnabled = true;
+		}
+
+		protected override void OnTearDown()
+		{
+			Sfi.Statistics.IsStatisticsEnabled = false;
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.CreateQuery("delete from ChildEntity").ExecuteUpdate();
+				session.CreateQuery("delete from System.Object").ExecuteUpdate();
+
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public async Task CanAddChildAfterFlushAsync()
+		{
+			Guid parentId;
+			Guid childId;
+			using (var session = OpenSession())
+			using (var t = session.BeginTransaction())
+			{
+				var parent = new Entity { Name = "Parent" };
+				var child = new ChildEntity { Name = "Child" };
+				parent.Children.Add(child);
+				await (session.SaveAsync(parent));
+				parent.Children.Remove(child);
+				parentId = parent.Id;
+				childId = child.Id;
+				await (t.CommitAsync());
+			}
+
+			using (var session = OpenSession())
+			using (var _ = session.BeginTransaction())
+			{
+				var parent = await (session.GetAsync<Entity>(parentId));
+				Assert.That(parent, Is.Not.Null);
+				Assert.That(parent.Children, Has.Count.EqualTo(0));
+
+				var child = await (session.GetAsync<ChildEntity>(childId));
+				Assert.That(child, Is.Null);
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH3325/Entity.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+
+namespace NHibernate.Test.NHSpecificTest.GH3325
+{
+	public class Entity
+	{
+		public virtual Guid Id { get; set; }
+		public virtual int Version { get; set; } = -1;
+		public virtual string Name { get; set; }
+		public virtual ISet<ChildEntity> Children { get; set; } = new HashSet<ChildEntity>();
+	}
+
+	public class EntityWithoutDeleteOrphan
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+		public virtual ISet<ChildEntity> Children { get; set; } = new HashSet<ChildEntity>();
+	}
+
+	public class ChildEntity
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH3325/Fixture.cs

@@ -0,0 +1,57 @@
+using System;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH3325
+{
+	[TestFixture]
+	public class Fixture : BugTestCase
+	{
+		protected override void OnSetUp()
+		{
+			Sfi.Statistics.IsStatisticsEnabled = true;
+		}
+
+		protected override void OnTearDown()
+		{
+			Sfi.Statistics.IsStatisticsEnabled = false;
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.CreateQuery("delete from ChildEntity").ExecuteUpdate();
+				session.CreateQuery("delete from System.Object").ExecuteUpdate();
+
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public void CanAddChildAfterFlush()
+		{
+			Guid parentId;
+			Guid childId;
+			using (var session = OpenSession())
+			using (var t = session.BeginTransaction())
+			{
+				var parent = new Entity { Name = "Parent" };
+				var child = new ChildEntity { Name = "Child" };
+				parent.Children.Add(child);
+				session.Save(parent);
+				parent.Children.Remove(child);
+				parentId = parent.Id;
+				childId = child.Id;
+				t.Commit();
+			}
+
+			using (var session = OpenSession())
+			using (var _ = session.BeginTransaction())
+			{
+				var parent = session.Get<Entity>(parentId);
+				Assert.That(parent, Is.Not.Null);
+				Assert.That(parent.Children, Has.Count.EqualTo(0));
+
+				var child = session.Get<ChildEntity>(childId);
+				Assert.That(child, Is.Null);
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH3325/Mappings.hbm.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="NHibernate.Test"
+                   namespace="NHibernate.Test.NHSpecificTest.GH3325">
+
+  <class name="Entity">
+    <id name="Id" generator="guid.comb"/>
+    <version name="Version" column="Version" type="Int32" unsaved-value="-1" />
+    <property name="Name"/>
+    <set name="Children" cascade="persist,delete,save-update,evict,lock,replicate,delete-orphan" collection-type="PersistentSetType`1[ChildEntity]">
+      <key column="Parent" />
+      <one-to-many class="ChildEntity"/>
+    </set>
+  </class>
+
+  <class name="EntityWithoutDeleteOrphan">
+    <id name="Id" generator="guid.comb"/>
+    <property name="Name"/>
+    <set name="Children" cascade="persist,merge,save-update">
+      <key column="ParentWdo" />
+      <one-to-many class="ChildEntity"/>
+    </set>
+  </class>
+
+  <class name="ChildEntity">
+    <!-- Do not use a persisted on save generator for children. Otherwise flush cascade may
+         trigger parent insertion as a side effect, which tends to hide troubles. -->
+    <id name="Id" generator="guid.comb"/>
+    <property name="Name"/>
+  </class>
+
+</hibernate-mapping>

src/NHibernate.Test/NHSpecificTest/GH3325/PersistentSetType.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using NHibernate.Collection;
+using NHibernate.Collection.Generic;
+using NHibernate.Engine;
+using NHibernate.Persister.Collection;
+using NHibernate.UserTypes;
+
+namespace NHibernate.Test.NHSpecificTest.GH3325
+{
+	public class PersistentSetType<T> : IUserCollectionType {
+		IPersistentCollection IUserCollectionType.Instantiate(ISessionImplementor session, ICollectionPersister persister) {
+			return new PersistentGenericSet<T>(session);
+		}
+
+		IPersistentCollection IUserCollectionType.Wrap(ISessionImplementor session, object collection) {
+			return new PersistentGenericSet<T>(session, (ISet<T>) collection);
+		}
+
+		object IUserCollectionType.ReplaceElements(object original, object target, ICollectionPersister persister, object owner, IDictionary copyCache, ISessionImplementor session) {
+			object result = target;
+			Clear(result);
+
+			foreach (object obj in (IEnumerable) original) {
+				Add(result, CopyElement(persister, obj, session, owner, copyCache));
+			}
+
+			return result;
+		}
+
+		protected virtual object CopyElement(ICollectionPersister persister, object element, ISessionImplementor session,
+		                                     object owner, IDictionary copiedAlready) {
+			return persister.ElementType.Replace(element, null, session, owner, copiedAlready);
+		}
+
+		object IUserCollectionType.Instantiate(int anticipatedSize) {
+			return new HashSetWithICollection<T>();
+		}
+
+		public IEnumerable GetElements(object collection) {
+			return (ISet<T>) collection;
+		}
+
+		public bool Contains(object collection, object entity) {
+			return ((ISet<T>) collection).Contains((T) entity);
+		}
+
+		public object IndexOf(object collection, object entity) {
+			throw new NotSupportedException();
+		}
+
+		protected virtual void Add(object collection, object element) {
+			((ISet<T>) collection).Add((T) element);
+		}
+
+		protected virtual void Clear(object collection) {
+			((ISet<T>) collection).Clear();
+		}
+	}
+
+	public class HashSetWithICollection<T> : HashSet<T>, ICollection {
+		public void CopyTo(Array array, int index) {
+			this.Cast<object>().ToArray().CopyTo(array, index);
+		}
+
+		public object SyncRoot => this;
+		public bool IsSynchronized => false;
+	}
+}

src/NHibernate/Async/Event/Default/AbstractSaveEventListener.cs

@@ -210,7 +210,7 @@ protected virtual async Task<object> PerformSaveOrReplicateAsync(object entity,
 
 			if (persister.HasCollections)
 			{
-				substitute = substitute || await (VisitCollectionsBeforeSaveAsync(entity, id, values, types, source, cancellationToken)).ConfigureAwait(false);
+				substitute = substitute | await (VisitCollectionsBeforeSaveAsync(entity, id, values, types, source, cancellationToken)).ConfigureAwait(false);
 			}
 
 			if (substitute)

src/NHibernate/Event/Default/AbstractSaveEventListener.cs

@@ -235,7 +235,7 @@ protected virtual object PerformSaveOrReplicate(object entity, EntityKey key, IE
 
 			if (persister.HasCollections)
 			{
-				substitute = substitute || VisitCollectionsBeforeSave(entity, id, values, types, source);
+				substitute = substitute | VisitCollectionsBeforeSave(entity, id, values, types, source);
 			}
 
 			if (substitute)