Fix components list lazy loading with not lazy associations (#3321)

Fixes #3317

src/NHibernate.Test/Async/NHSpecificTest/GH3317/FixtureByCode.cs

@@ -0,0 +1,123 @@
+//------------------------------------------------------------------------------
+// <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 System.Linq;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Mapping.ByCode;
+using NHibernate.Linq;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH3317
+{
+	using System.Threading.Tasks;
+	[TestFixture(true)]
+	[TestFixture(false)]
+	public class ComponentsListFixtureAsync : TestCaseMappingByCode
+	{
+		private readonly bool _fetchJoinMapping;
+		private Guid _id;
+
+		public ComponentsListFixtureAsync(bool fetchJoinMapping)
+		{
+			_fetchJoinMapping = fetchJoinMapping;
+		}
+
+		protected override void OnSetUp()
+		{
+			using var session = OpenSession();
+			using var tr = session.BeginTransaction();
+			var root = new Entity();
+			root.Entries.Add(new ComponentListEntry { ComponentReference = null, DummyString = "one", });
+
+			session.Save(root);
+			tr.Commit();
+			_id = root.Id;
+		}
+
+		[Test]
+		public async Task LazyLoadingAsync()
+		{
+			using var newSession = OpenSession();
+			var reloadedRoot = await (newSession.GetAsync<Entity>(_id));
+			Assert.AreEqual(1, reloadedRoot.Entries.Count);
+		}
+
+		[Test]
+		public async Task QueryOverFetchAsync()
+		{
+			using var newSession = OpenSession();
+			var reloadedRoot = await (newSession.QueryOver<Entity>()
+				.Fetch(SelectMode.Fetch, x => x.Entries)
+				.Where(x => x.Id == _id)
+				.SingleOrDefaultAsync());
+			Assert.AreEqual(1, reloadedRoot.Entries.Count);
+		}
+
+		[Test]
+		public async Task LinqFetchAsync()
+		{
+			using var newSession = OpenSession();
+			var reloadedRoot = await (newSession.Query<Entity>()
+				.Fetch(x => x.Entries)
+				.Where(x => x.Id == _id)
+				.SingleOrDefaultAsync());
+			Assert.AreEqual(1, reloadedRoot.Entries.Count);
+		}
+
+		protected override void OnTearDown()
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+			session.CreateSQLQuery("delete from Entries").ExecuteUpdate();
+			session.Delete("from System.Object");
+			transaction.Commit();
+		}
+
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.Class<Entity>(rc =>
+			{
+				rc.Id(x => x.Id, map => map.Generator(Generators.GuidComb));
+				rc.Lazy(false);
+				rc.Property(x => x.Name);
+
+				rc.Bag(
+					x => x.Entries,
+					v =>
+					{
+						if (_fetchJoinMapping)
+							v.Fetch(CollectionFetchMode.Join);
+					},
+					h => h.Component(cmp =>
+					{
+						cmp.Property(x => x.DummyString);
+						cmp.ManyToOne(x => x.ComponentReference);
+					}));
+			});
+			mapper.Class<EntityWithParent>(rc =>
+			{
+				rc.Id(x => x.Id, map => map.Generator(Generators.GuidComb));
+				rc.Lazy(false);
+				rc.ManyToOne(x => x.Parent, m => m.NotNullable(true));
+			});
+			mapper.Class<ParentEntity>(rc =>
+			{
+				rc.Id(x => x.Id, map => map.Generator(Generators.GuidComb));
+				rc.Lazy(false);
+				rc.Property(x => x.Name);
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH3317/Entity.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+
+namespace NHibernate.Test.NHSpecificTest.GH3317
+{
+	public class Entity
+	{
+		public Guid Id { get; set; }
+		public string Name { get; set; }
+		public IList<ComponentListEntry> Entries { get; set; } = new List<ComponentListEntry>();
+	}
+
+	public class ComponentListEntry
+	{
+		public string DummyString { get; set; }
+		public EntityWithParent ComponentReference { get; set; }
+	}
+
+	public class EntityWithParent
+	{
+		public Guid Id { get; set; }
+		public ParentEntity Parent { get; set; }
+	}
+
+	public class ParentEntity
+	{
+		public Guid Id { get; set; }
+		public string Name { get; set; }
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH3317/FixtureByCode.cs

@@ -0,0 +1,112 @@
+using System;
+using System.Linq;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Mapping.ByCode;
+using NHibernate.Linq;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH3317
+{
+	[TestFixture(true)]
+	[TestFixture(false)]
+	public class ComponentsListFixture : TestCaseMappingByCode
+	{
+		private readonly bool _fetchJoinMapping;
+		private Guid _id;
+
+		public ComponentsListFixture(bool fetchJoinMapping)
+		{
+			_fetchJoinMapping = fetchJoinMapping;
+		}
+
+		protected override void OnSetUp()
+		{
+			using var session = OpenSession();
+			using var tr = session.BeginTransaction();
+			var root = new Entity();
+			root.Entries.Add(new ComponentListEntry { ComponentReference = null, DummyString = "one", });
+
+			session.Save(root);
+			tr.Commit();
+			_id = root.Id;
+		}
+
+		[Test]
+		public void LazyLoading()
+		{
+			using var newSession = OpenSession();
+			var reloadedRoot = newSession.Get<Entity>(_id);
+			Assert.AreEqual(1, reloadedRoot.Entries.Count);
+		}
+
+		[Test]
+		public void QueryOverFetch()
+		{
+			using var newSession = OpenSession();
+			var reloadedRoot = newSession.QueryOver<Entity>()
+				.Fetch(SelectMode.Fetch, x => x.Entries)
+				.Where(x => x.Id == _id)
+				.SingleOrDefault();
+			Assert.AreEqual(1, reloadedRoot.Entries.Count);
+		}
+
+		[Test]
+		public void LinqFetch()
+		{
+			using var newSession = OpenSession();
+			var reloadedRoot = newSession.Query<Entity>()
+				.Fetch(x => x.Entries)
+				.Where(x => x.Id == _id)
+				.SingleOrDefault();
+			Assert.AreEqual(1, reloadedRoot.Entries.Count);
+		}
+
+		protected override void OnTearDown()
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+			session.CreateSQLQuery("delete from Entries").ExecuteUpdate();
+			session.Delete("from System.Object");
+			transaction.Commit();
+		}
+
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.Class<Entity>(rc =>
+			{
+				rc.Id(x => x.Id, map => map.Generator(Generators.GuidComb));
+				rc.Lazy(false);
+				rc.Property(x => x.Name);
+
+				rc.Bag(
+					x => x.Entries,
+					v =>
+					{
+						if (_fetchJoinMapping)
+							v.Fetch(CollectionFetchMode.Join);
+					},
+					h => h.Component(cmp =>
+					{
+						cmp.Property(x => x.DummyString);
+						cmp.ManyToOne(x => x.ComponentReference);
+					}));
+			});
+			mapper.Class<EntityWithParent>(rc =>
+			{
+				rc.Id(x => x.Id, map => map.Generator(Generators.GuidComb));
+				rc.Lazy(false);
+				rc.ManyToOne(x => x.Parent, m => m.NotNullable(true));
+			});
+			mapper.Class<ParentEntity>(rc =>
+			{
+				rc.Id(x => x.Id, map => map.Generator(Generators.GuidComb));
+				rc.Lazy(false);
+				rc.Property(x => x.Name);
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+	}
+}

src/NHibernate/Loader/JoinWalker.cs

@@ -375,6 +375,7 @@ private void WalkCollectionTree(IQueryableCollection persister, string alias, st
 				}
 				else if (type.IsComponentType)
 				{
+					_joinQueue.Enqueue(NextLevelJoinQueueEntry.Instance);
 					WalkCompositeElementTree(
 						(IAbstractComponentType) type,
 						persister.ElementColumnNames,