Test for Merging a bidirectional list creates unnecessary UPDATE statement

src/NHibernate.Test/Async/NHSpecificTest/GH1530/Fixture.cs

@@ -0,0 +1,116 @@
+//------------------------------------------------------------------------------
+// <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 NHibernate.Cfg;
+using NUnit.Framework;
+using Environment = NHibernate.Cfg.Environment;
+
+namespace NHibernate.Test.NHSpecificTest.GH1530
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public abstract class FixtureBaseAsync : BugTestCase
+	{
+		private Parent _parent;
+
+		protected override void OnSetUp()
+		{
+			using (var s = OpenSession())
+			{
+				using (var tx = s.BeginTransaction())
+				{
+					_parent = new Parent();
+					_parent.AddChild(new Child());
+					s.Save(_parent);
+					tx.Commit();
+				}
+			}
+		}
+
+		[Test]
+		public virtual async Task OneNewChildShouldOnlyCreateInsertWithNoUpdate_LockAndMergeAsync()
+		{
+			var parentClone = _parent.MakeCopy();
+			parentClone.AddChild(new Child());
+			using (var s = OpenSession())
+			{
+				using (var tx = s.BeginTransaction())
+				{
+					await (s.LockAsync(_parent, LockMode.None));
+					await (s.MergeAsync(parentClone));
+					s.SessionFactory.Statistics.Clear();
+					await (tx.CommitAsync());
+				}
+
+				Assert.That(s.SessionFactory.Statistics.PrepareStatementCount, Is.EqualTo(1));
+			}
+		}
+
+		[Test]
+		public virtual async Task OneNewChildShouldOnlyCreateInsertWithNoUpdate_MergeAsync()
+		{
+			var parentClone = _parent.MakeCopy();
+			parentClone.AddChild(new Child());
+			using (var s = OpenSession())
+			{
+				using (var tx = s.BeginTransaction())
+				{
+					await (s.MergeAsync(parentClone));
+					s.SessionFactory.Statistics.Clear();
+					await (tx.CommitAsync());
+				}
+
+				Assert.That(s.SessionFactory.Statistics.PrepareStatementCount, Is.EqualTo(1));
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var s = OpenSession())
+			{
+				using (var tx = s.BeginTransaction())
+				{
+					s.Delete(s.Load<Parent>(_parent.Id));
+					tx.Commit();
+				}
+			}
+		}
+
+		protected override void Configure(Configuration configuration)
+		{
+			configuration.SetProperty(Environment.GenerateStatistics, "true");
+		}
+	}
+
+	[TestFixture]
+	public class FixtureAsync : FixtureBaseAsync
+	{
+		[Test]
+		[KnownBug("#1530")]
+		public override async Task OneNewChildShouldOnlyCreateInsertWithNoUpdate_MergeAsync()
+		{
+			await (base.OneNewChildShouldOnlyCreateInsertWithNoUpdate_MergeAsync());
+		}
+
+		[Test]
+		[KnownBug("#1530")]
+		public override async Task OneNewChildShouldOnlyCreateInsertWithNoUpdate_LockAndMergeAsync()
+		{
+			await (base.OneNewChildShouldOnlyCreateInsertWithNoUpdate_LockAndMergeAsync());
+		}
+	}
+
+	[TestFixture]
+	public class NonInverseFixtureAsync : FixtureBaseAsync
+	{
+		protected override string[] Mappings => new[] { "NonInverseMappings.hbm.xml" };
+	}
+
+}

src/NHibernate.Test/NHSpecificTest/GH1530/Fixture.cs

@@ -0,0 +1,105 @@
+using NHibernate.Cfg;
+using NUnit.Framework;
+using Environment = NHibernate.Cfg.Environment;
+
+namespace NHibernate.Test.NHSpecificTest.GH1530
+{
+	[TestFixture]
+	public abstract class FixtureBase : BugTestCase
+	{
+		private Parent _parent;
+
+		protected override void OnSetUp()
+		{
+			using (var s = OpenSession())
+			{
+				using (var tx = s.BeginTransaction())
+				{
+					_parent = new Parent();
+					_parent.AddChild(new Child());
+					s.Save(_parent);
+					tx.Commit();
+				}
+			}
+		}
+
+		[Test]
+		public virtual void OneNewChildShouldOnlyCreateInsertWithNoUpdate_LockAndMerge()
+		{
+			var parentClone = _parent.MakeCopy();
+			parentClone.AddChild(new Child());
+			using (var s = OpenSession())
+			{
+				using (var tx = s.BeginTransaction())
+				{
+					s.Lock(_parent, LockMode.None);
+					s.Merge(parentClone);
+					s.SessionFactory.Statistics.Clear();
+					tx.Commit();
+				}
+
+				Assert.That(s.SessionFactory.Statistics.PrepareStatementCount, Is.EqualTo(1));
+			}
+		}
+
+		[Test]
+		public virtual void OneNewChildShouldOnlyCreateInsertWithNoUpdate_Merge()
+		{
+			var parentClone = _parent.MakeCopy();
+			parentClone.AddChild(new Child());
+			using (var s = OpenSession())
+			{
+				using (var tx = s.BeginTransaction())
+				{
+					s.Merge(parentClone);
+					s.SessionFactory.Statistics.Clear();
+					tx.Commit();
+				}
+
+				Assert.That(s.SessionFactory.Statistics.PrepareStatementCount, Is.EqualTo(1));
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var s = OpenSession())
+			{
+				using (var tx = s.BeginTransaction())
+				{
+					s.Delete(s.Load<Parent>(_parent.Id));
+					tx.Commit();
+				}
+			}
+		}
+
+		protected override void Configure(Configuration configuration)
+		{
+			configuration.SetProperty(Environment.GenerateStatistics, "true");
+		}
+	}
+
+	[TestFixture]
+	public class Fixture : FixtureBase
+	{
+		[Test]
+		[KnownBug("#1530")]
+		public override void OneNewChildShouldOnlyCreateInsertWithNoUpdate_Merge()
+		{
+			base.OneNewChildShouldOnlyCreateInsertWithNoUpdate_Merge();
+		}
+
+		[Test]
+		[KnownBug("#1530")]
+		public override void OneNewChildShouldOnlyCreateInsertWithNoUpdate_LockAndMerge()
+		{
+			base.OneNewChildShouldOnlyCreateInsertWithNoUpdate_LockAndMerge();
+		}
+	}
+
+	[TestFixture]
+	public class NonInverseFixture : FixtureBase
+	{
+		protected override string[] Mappings => new[] { "NonInverseMappings.hbm.xml" };
+	}
+
+}

src/NHibernate.Test/NHSpecificTest/GH1530/Mappings.hbm.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
+                   namespace="NHibernate.Test.NHSpecificTest.GH1530"
+                   assembly="NHibernate.Test">
+  <class name="Parent">
+    <id name="Id" type="guid">
+      <generator class="guid.comb"/>
+    </id>
+    <list name="Children" cascade="all-delete-orphan" inverse="true">
+      <key column="Parent" not-null="true"/>
+      <list-index column="OrderIndex"/>
+      <one-to-many class="Child"/>
+    </list>
+    <property name="Name"/>
+  </class>
+
+  <class name="Child">
+    <id name="Id" type="guid">
+      <generator class="guid.comb"/>
+    </id>
+    <many-to-one name="Parent" class="Parent"/>
+    <property name="OrderIndex" access="readonly"/>
+    <property name="Name"/>
+  </class>
+</hibernate-mapping>

src/NHibernate.Test/NHSpecificTest/GH1530/Model.cs

@@ -0,0 +1,66 @@
+using System;
+using System.Collections.Generic;
+
+namespace NHibernate.Test.NHSpecificTest.GH1530
+{
+	public class Parent
+	{
+		public virtual Guid Id { get; set; }
+		public virtual IList<Child> Children { get; set; } = new List<Child>();
+		public virtual string Name { get; set; } = Guid.NewGuid().ToString();
+
+		public virtual void AddChild(Child child)
+		{
+			Children.Add(child);
+			child.Parent = this;
+		}
+
+		public virtual Parent MakeCopy()
+		{
+			var ret = new Parent { Id = Id, Name = Name };
+			foreach (var child in Children)
+			{
+				ret.AddChild(new Child { Id = child.Id, Name = child.Name });
+			}
+
+			return ret;
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is Parent other && Id == other.Id;
+		}
+
+		public override int GetHashCode()
+		{
+			return 0;
+		}
+	}
+
+	public class Child
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; } = Guid.NewGuid().ToString();
+		public virtual Parent Parent { get; set; }
+
+		public virtual int OrderIndex
+		{
+			get
+			{
+				if (Parent == null)
+					return -2;
+				return Parent.Children.IndexOf(this);
+			}
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is Child other && Id == other.Id;
+		}
+
+		public override int GetHashCode()
+		{
+			return 0;
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH1530/NonInverseMappings.hbm.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
+                   namespace="NHibernate.Test.NHSpecificTest.GH1530"
+                   assembly="NHibernate.Test">
+  <class name="Parent">
+    <id name="Id" type="guid">
+      <generator class="guid.comb"/>
+    </id>
+    <list name="Children" cascade="all-delete-orphan">
+      <key column="Parent" not-null="true" update="false"/>
+      <list-index column="OrderIndex"/>
+      <one-to-many class="Child"/>
+    </list>
+    <property name="Name"/>
+  </class>
+
+
+  <class name="Child">
+    <id name="Id" type="guid">
+      <generator class="guid.comb"/>
+    </id>
+    <many-to-one name="Parent" class="Parent" update="false" insert="false"/>
+    <property name="Name"/>
+  </class>
+</hibernate-mapping>