Fix NRE with merge and ignore not-found

src/NHibernate.Test/Async/NHSpecificTest/GH2627/Fixture.cs

@@ -0,0 +1,69 @@
+//------------------------------------------------------------------------------
+// <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.Linq;
+using NUnit.Framework;
+using NHibernate.Linq;
+
+namespace NHibernate.Test.NHSpecificTest.GH2627
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class FixtureAsync : BugTestCase
+	{
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var e1 = new Entity {Name = "Bob"};
+				session.Save(e1);
+
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.CreateQuery("delete from Child").ExecuteUpdate();
+				session.CreateQuery("delete from System.Object").ExecuteUpdate();
+
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public async Task NullRefInMergeAsync()
+		{
+			Child child;
+			using (var session = OpenSession())
+			using (var t = session.BeginTransaction())
+			{
+				child = new Child
+				{
+					Parent = await (session.Query<Entity>().FirstOrDefaultAsync()),
+					Name = "John"
+				};
+
+				await (t.CommitAsync());
+			}
+
+			using (var session = OpenSession())
+			using (var t = session.BeginTransaction())
+			{
+				await (session.MergeAsync(child));
+				await (t.CommitAsync());
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2627/Child.cs

@@ -0,0 +1,11 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH2627
+{
+	public class Child
+	{
+		public virtual Guid Id { get; set; }
+		public virtual Entity Parent { get; set; }
+		public virtual string Name { get; set; }
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2627/Entity.cs

@@ -0,0 +1,10 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH2627
+{
+	public class Entity
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2627/Fixture.cs

@@ -0,0 +1,57 @@
+using System.Linq;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH2627
+{
+	[TestFixture]
+	public class Fixture : BugTestCase
+	{
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var e1 = new Entity {Name = "Bob"};
+				session.Save(e1);
+
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.CreateQuery("delete from Child").ExecuteUpdate();
+				session.CreateQuery("delete from System.Object").ExecuteUpdate();
+
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public void NullRefInMerge()
+		{
+			Child child;
+			using (var session = OpenSession())
+			using (var t = session.BeginTransaction())
+			{
+				child = new Child
+				{
+					Parent = session.Query<Entity>().FirstOrDefault(),
+					Name = "John"
+				};
+
+				t.Commit();
+			}
+
+			using (var session = OpenSession())
+			using (var t = session.BeginTransaction())
+			{
+				session.Merge(child);
+				t.Commit();
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2627/Mappings.hbm.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="NHibernate.Test"
+                   namespace="NHibernate.Test.NHSpecificTest.GH2627">
+
+  <class name="Entity">
+    <id name="Id" generator="guid.comb"/>
+    <property name="Name"/>
+  </class>
+
+  <class name="Child">
+    <id name="Id" generator="guid.comb"/>
+    <property name="Name"/>
+    <many-to-one name="Parent" not-found="ignore"/>
+  </class>
+
+</hibernate-mapping>

src/NHibernate/Async/Type/ManyToOneType.cs

@@ -11,7 +11,6 @@
 using System;
 using System.Data.Common;
 using NHibernate.Engine;
-using NHibernate.Persister.Entity;
 using NHibernate.SqlTypes;
 using NHibernate.Util;
 

src/NHibernate/Cfg/XmlHbmBinding/ClassCompositeIdBinder.cs

@@ -101,7 +101,7 @@ private void BindComponent(System.Type reflectedClass, string path, HbmComposite
 
 				if (keyManyToOneSchema != null)
 				{
-					var manyToOne = new ManyToOne(compositeId.Table);
+					var manyToOne = new ManyToOne(compositeId.Table, compositeId.Owner);
 
 					string propertyName = keyManyToOneSchema.name == null ? null : StringHelper.Qualify(path, keyManyToOneSchema.name);
 

src/NHibernate/Cfg/XmlHbmBinding/CollectionBinder.cs

@@ -655,13 +655,13 @@ private void BindMapSecondPass(HbmMap mapMapping, Map model,
 			}
 			else if ((indexManyToManyMapping = mapMapping.Item as HbmIndexManyToMany) != null)
 			{
-				var manyToOne = new ManyToOne(model.CollectionTable);
+				var manyToOne = new ManyToOne(model.CollectionTable, model.Owner);
 				BindIndexManyToMany(indexManyToManyMapping, manyToOne, IndexedCollection.DefaultIndexColumnName, model.IsOneToMany);
 				model.Index = manyToOne;
 			}
 			else if ((mapKeyManyToManyMapping = mapMapping.Item as HbmMapKeyManyToMany) != null)
 			{
-				var manyToOne = new ManyToOne(model.CollectionTable);
+				var manyToOne = new ManyToOne(model.CollectionTable, model.Owner);
 				BindMapKeyManyToMany(mapKeyManyToManyMapping, manyToOne, IndexedCollection.DefaultIndexColumnName, model.IsOneToMany);
 				model.Index = manyToOne;
 			}
@@ -813,7 +813,7 @@ private void BindCollectionSecondPass(ICollectionPropertiesMapping collectionMap
 
 		private void BindManyToMany(HbmManyToMany manyToManyMapping, Mapping.Collection model)
 		{
-			var manyToMany = new ManyToOne(model.CollectionTable);
+			var manyToMany = new ManyToOne(model.CollectionTable, model.Owner);
 			model.Element = manyToMany;
 			new ValuePropertyBinder(manyToMany, Mappings).BindSimpleValue(manyToManyMapping,
 																	   Mapping.Collection.DefaultElementColumnName, false);

src/NHibernate/Cfg/XmlHbmBinding/PropertiesBinder.cs

@@ -129,7 +129,7 @@ public void Bind(IEnumerable<IEntityPropertyMapping> properties, Table table, ID
 				}
 				else if ((manyToOneMapping = entityPropertyMapping as HbmManyToOne) != null)
 				{
-					var value = new ManyToOne(table);
+					var value = new ManyToOne(table, persistentClass);
 					BindManyToOne(manyToOneMapping, value, propertyName, true);
 					property = CreateProperty(entityPropertyMapping, className, value, inheritedMetas);
 					BindManyToOneProperty(manyToOneMapping, property);
@@ -189,7 +189,7 @@ public void Bind(IEnumerable<IEntityPropertyMapping> properties, Table table, ID
 				}
 				else if ((keyManyToOneMapping = entityPropertyMapping as HbmKeyManyToOne) != null)
 				{
-					var value = new ManyToOne(table);
+					var value = new ManyToOne(table, persistentClass);
 					BindKeyManyToOne(keyManyToOneMapping, value, propertyName, componetDefaultNullable);
 					property = CreateProperty(entityPropertyMapping, className, value, inheritedMetas);
 				}

src/NHibernate/Mapping/ManyToOne.cs

@@ -9,11 +9,24 @@ namespace NHibernate.Mapping
 	[Serializable]
 	public class ManyToOne : ToOne
 	{
+		private readonly string _entityName;
+
+		/// <summary>
+		/// Construct a many-to-one mapping.
+		/// </summary>
+		/// <param name="table">The table.</param>
+		/// <param name="owner">The association owner.</param>
+		public ManyToOne(Table table, PersistentClass owner) : base(table)
+		{
+			_entityName = owner?.EntityName;
+		}
+
 		/// <summary>
 		/// 
 		/// </summary>
 		/// <param name="table"></param>
-		public ManyToOne(Table table) : base(table)
+		[Obsolete("Use overload with owner instead.")]
+		public ManyToOne(Table table) : this(table, null)
 		{
 		}
 
@@ -41,7 +54,7 @@ public bool IsLogicalOneToOne
 			get { return isLogicalOneToOne; }
 			set { isLogicalOneToOne = value; }
 		}
-		
+
 		public string PropertyName { get; set; }
 
 		private IType type;
@@ -51,8 +64,9 @@ public override IType Type
 			{
 				if (type == null)
 				{
-					type =
-						TypeFactory.ManyToOne(ReferencedEntityName, ReferencedPropertyName, IsLazy, UnwrapProxy, IsIgnoreNotFound, isLogicalOneToOne, PropertyName);
+					type = TypeFactory.ManyToOne(
+						ReferencedEntityName, ReferencedPropertyName, IsLazy, UnwrapProxy,
+						IsIgnoreNotFound, isLogicalOneToOne, _entityName, PropertyName);
 				}
 				return type;
 			}

src/NHibernate/Mapping/OneToMany.cs

@@ -23,7 +23,9 @@ public OneToMany(PersistentClass owner)
 
 		private EntityType EntityType
 		{
-			get { return TypeFactory.ManyToOne(ReferencedEntityName, null, false, false, IsIgnoreNotFound, false, null); }
+			get { return TypeFactory.ManyToOne(
+				ReferencedEntityName, null, false, false, 
+				IsIgnoreNotFound, false, null, null); }
 		}
 
 		public bool IsIgnoreNotFound

src/NHibernate/Type/ManyToOneType.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Data.Common;
 using NHibernate.Engine;
-using NHibernate.Persister.Entity;
 using NHibernate.SqlTypes;
 using NHibernate.Util;
 
@@ -15,6 +14,7 @@ public partial class ManyToOneType : EntityType
 	{
 		private readonly bool ignoreNotFound;
 		private readonly bool isLogicalOneToOne;
+		private readonly string _entityName;
 
 		public ManyToOneType(string className)
 			: this(className, false)
@@ -30,18 +30,41 @@ public ManyToOneType(string className, bool lazy)
 		}
 
 		//Since 5.3
-		[Obsolete("Use Constructor with property name")]
+		[Obsolete("Use Constructor with owner property name and property name")]
 		public ManyToOneType(string entityName, string uniqueKeyPropertyName, bool lazy, bool unwrapProxy, bool ignoreNotFound, bool isLogicalOneToOne)
-			: this(entityName, uniqueKeyPropertyName, lazy, unwrapProxy, ignoreNotFound, isLogicalOneToOne, null)
+			: this(entityName, uniqueKeyPropertyName, lazy, unwrapProxy, ignoreNotFound, isLogicalOneToOne, null, null)
 		{
 		}
 
+		//Since 5.3.6
+		[Obsolete("Use Constructor with owner entity name")]
 		public ManyToOneType(string entityName, string uniqueKeyPropertyName, bool lazy, bool unwrapProxy, bool ignoreNotFound, bool isLogicalOneToOne, string propertyName)
-			: base(entityName, uniqueKeyPropertyName, !lazy, unwrapProxy)
+			: this(entityName, uniqueKeyPropertyName, lazy, unwrapProxy, ignoreNotFound, isLogicalOneToOne, null, propertyName)
+		{
+		}
+
+		/// <summary>
+		/// Build a many-to-one relation.
+		/// </summary>
+		/// <param name="referencedEntityName">The referenced entity name.</param>
+		/// <param name="uniqueKeyPropertyName">The property-ref name, or <see langword="null" /> if we reference
+		/// the PK of the associated entity.</param>
+		/// <param name="lazy">Is the association lazily loaded?</param>
+		/// <param name="unwrapProxy">Is unwrapping of proxies allowed for this association; unwrapping says to return
+		/// the "implementation target" of lazy proxies; typically only possible with lazy="no-proxy".</param>
+		/// <param name="ignoreNotFound"><see langword="false" /> for throwing an exception if the referenced
+		/// entity is missing in the database, <see langword="true" /> for yielding <see langword="null" /> instead.</param>
+		/// <param name="isLogicalOneToOne"></param>
+		/// <param name="entityName">The property owner entity name.</param>
+		/// <param name="propertyName">The property name.</param>
+		public ManyToOneType(string referencedEntityName, string uniqueKeyPropertyName, bool lazy, bool unwrapProxy,
+		                     bool ignoreNotFound, bool isLogicalOneToOne, string entityName, string propertyName)
+			: base(referencedEntityName, uniqueKeyPropertyName, !lazy, unwrapProxy)
 		{
 			this.ignoreNotFound = ignoreNotFound;
 			this.isLogicalOneToOne = isLogicalOneToOne;
 			PropertyName = propertyName;
+			_entityName = entityName;
 		}
 
 		public override int GetColumnSpan(IMapping mapping)
@@ -162,11 +185,16 @@ private bool IsIdentifier(object value, ISessionImplementor session)
 
 		public override bool IsNull(object owner, ISessionImplementor session)
 		{
-			if (IsNullable && !string.IsNullOrEmpty(PropertyName))
+			if (IsNullable && !string.IsNullOrEmpty(PropertyName) && owner != null)
 			{
-				EntityEntry entry = session.PersistenceContext.GetEntry(owner);
+				var ownerPersister = session.Factory.GetEntityPersister(_entityName);
+				var id = session.GetContextEntityIdentifier(owner);
+				if (id == null)
+					return false;
+
+				var entityKey = session.GenerateEntityKey(id, ownerPersister);
 
-				return session.PersistenceContext.IsPropertyNull(entry.EntityKey, PropertyName);
+				return session.PersistenceContext.IsPropertyNull(entityKey, PropertyName);
 			}
 
 			return false;