Add test case for one-to-one with property ref SOE

Co-authored-by: Michael Estermann <michael.estermann@bbv.ch>

Author: fredericDelaporte

src/NHibernate.Test/NHSpecificTest/GH1645/EntityBase.cs

@@ -0,0 +1,67 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH1645
+{
+	public abstract class EntityBase
+	{
+		public virtual Guid Id { get; protected set; }
+
+		public static bool operator ==(EntityBase left, EntityBase right)
+		{
+			return Equals(left, right);
+		}
+
+		public static bool operator !=(EntityBase left, EntityBase right)
+		{
+			return !Equals(left, right);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return Equals(obj as EntityBase);
+		}
+
+		public virtual bool Equals(EntityBase other)
+		{
+			if (other == null)
+			{
+				return false;
+			}
+
+			if (ReferenceEquals(this, other))
+			{
+				return true;
+			}
+
+			if (!IsTransient(this) && !IsTransient(other) && Equals(Id, other.Id))
+			{
+				var otherType = other.GetUnproxiedType();
+				var thisType = GetUnproxiedType();
+				return thisType.IsAssignableFrom(otherType) ||
+					otherType.IsAssignableFrom(thisType);
+			}
+
+			return false;
+		}
+
+		public override int GetHashCode()
+		{
+			if (Equals(Id, default(Guid)))
+			{
+				return base.GetHashCode();
+			}
+
+			return Id.GetHashCode();
+		}
+
+		private static bool IsTransient(EntityBase obj)
+		{
+			return obj != null && Equals(obj.Id, default(Guid));
+		}
+
+		private System.Type GetUnproxiedType()
+		{
+			return GetType();
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH1645/Fixture.cs

@@ -0,0 +1,53 @@
+using System;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH1645
+{
+	[TestFixture]
+	public class Fixture : BugTestCase
+	{
+		private Guid _superParentId;
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var p = new Parent();
+				session.Save(p);
+
+				_superParentId = (Guid) session.Save(new SuperParent { Parent = p });
+
+				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 NHbernate 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 SOEOnLoad()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var superParent = session.Load<SuperParent>(_superParentId);
+				Assert.That(() => NHibernateUtil.Initialize(superParent), Throws.Nothing);
+				Assert.That(() => NHibernateUtil.Initialize(superParent.Parent), Throws.Nothing);
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH1645/Mappings.hbm.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="NHibernate.Test"
+                   namespace="NHibernate.Test.NHSpecificTest.GH1645">
+
+  <class name="SuperParent">
+    <id name="Id" generator="guid.comb"/>
+    <many-to-one name="Parent"/>
+  </class>
+
+  <class name="Parent">
+    <id name="Id" generator="guid.comb"/>
+    <one-to-one name="SuperParent" property-ref="Parent"/>
+  </class>
+
+</hibernate-mapping>

src/NHibernate.Test/NHSpecificTest/GH1645/Parent.cs

@@ -0,0 +1,7 @@
+namespace NHibernate.Test.NHSpecificTest.GH1645
+{
+	public class Parent : EntityBase
+	{
+		public virtual SuperParent SuperParent { get; set; }
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH1645/SuperParent.cs

@@ -0,0 +1,7 @@
+namespace NHibernate.Test.NHSpecificTest.GH1645
+{
+    public class SuperParent : EntityBase
+    {
+        public virtual Parent Parent { get; set; }
+    }
+}