Fix NullReferenceException in EntityEntry.GetLoadedValue

Fixes #2137

Co-authored-by: Roman Artiukhin <bahusdrive@gmail.com>

Author: 2 people

src/NHibernate.Test/Async/NHSpecificTest/GH2137/Fixture.cs

@@ -0,0 +1,61 @@
+//------------------------------------------------------------------------------
+// <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 NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH2137
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class FixtureAsync : BugTestCase
+	{
+		private Entity e1;
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				e1 = new Entity {Name = "Bob"};
+				session.Save(e1);
+
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				// The HQL delete does all the job inside the database without loading the entities, but it does
+				// not handle delete order for avoiding violating constraints if any. Use
+				// session.Delete("from System.Object");
+				// instead if in need of having NHibernate ordering the deletes, but this will cause
+				// loading the entities in the session.
+				session.CreateQuery("delete from System.Object").ExecuteUpdate();
+
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public async Task TestUpdateDetachedEntityAsync()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				e1.Name = "Sally";
+				await (session.UpdateAsync(e1));
+				await (transaction.CommitAsync());
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2137/Entity.cs

@@ -0,0 +1,18 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH2137
+{
+	class Entity
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+		public virtual ExtendedProperties ExtendedProperties { get; set; }
+	}
+
+	class ExtendedProperties
+	{
+		public virtual Guid Id { get; set; }
+
+		public virtual string Value { get; set; }
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2137/Fixture.cs

@@ -0,0 +1,50 @@
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH2137
+{
+	[TestFixture]
+	public class Fixture : BugTestCase
+	{
+		private Entity e1;
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				e1 = new Entity {Name = "Bob"};
+				session.Save(e1);
+
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				// The HQL delete does all the job inside the database without loading the entities, but it does
+				// not handle delete order for avoiding violating constraints if any. Use
+				// session.Delete("from System.Object");
+				// instead if in need of having NHibernate ordering the deletes, but this will cause
+				// loading the entities in the session.
+				session.CreateQuery("delete from System.Object").ExecuteUpdate();
+
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public void TestUpdateDetachedEntity()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				e1.Name = "Sally";
+				session.Update(e1);
+				transaction.Commit();
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2137/Mappings.hbm.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="NHibernate.Test"
+                   namespace="NHibernate.Test.NHSpecificTest.GH2137">
+
+  <class name="Entity">
+    <id name="Id" generator="guid.comb"/>
+    <property name="Name"/>
+    <many-to-one name="ExtendedProperties" class="ExtendedProperties" unique="true" cascade="all-delete-orphan" lazy="proxy" />
+
+  </class>
+
+  <class name="ExtendedProperties">
+    <id name="Id" generator="guid.comb"/>
+    <property name="Value" column="`Value`"/>
+  </class>
+
+</hibernate-mapping>

src/NHibernate/Async/Engine/Cascade.cs

@@ -117,7 +117,8 @@ private async Task CascadePropertyAsync(object parent, object child, IType type,
 						// value is orphaned if loaded state for this property shows not null
 						// because it is currently null.
 						EntityEntry entry = eventSource.PersistenceContext.GetEntry(parent);
-						if (entry != null && entry.Status != Status.Saving)
+						//LoadedState is null when detached entity is cascaded from session.Update context
+						if (entry?.LoadedState != null && entry.Status != Status.Saving)
 						{
 							object loadedValue;
 							if (componentPathStack.Count == 0)

src/NHibernate/Engine/Cascade.cs

@@ -169,7 +169,8 @@ private void CascadeProperty(object parent, object child, IType type, CascadeSty
 						// value is orphaned if loaded state for this property shows not null
 						// because it is currently null.
 						EntityEntry entry = eventSource.PersistenceContext.GetEntry(parent);
-						if (entry != null && entry.Status != Status.Saving)
+						//LoadedState is null when detached entity is cascaded from session.Update context
+						if (entry?.LoadedState != null && entry.Status != Status.Saving)
 						{
 							object loadedValue;
 							if (componentPathStack.Count == 0)