Fix missing alias for subquery entity references in update statements (#2218)

Fixes #1015

Author: bahusoid

src/NHibernate.Test/Async/Hql/AggregateFunctionsWithSubSelectTest.cs

@@ -16,7 +16,6 @@
 namespace NHibernate.Test.Hql
 {
 	using System.Threading.Tasks;
-	using System.Threading;
 	[TestFixture]
 	public class AggregateFunctionsWithSubSelectTestAsync : TestCaseMappingByCode
 	{
@@ -88,7 +87,7 @@ protected override bool AppliesTo(Dialect.Dialect dialect)
 		[TestCase("MIN", 2)]
 		[TestCase("MAX", 2)]
 		[TestCase("AVG", 2d)]
-		public async Task TestAggregateFunctionAsync(string functionName, object result, CancellationToken cancellationToken = default(CancellationToken))
+		public async Task TestAggregateFunctionAsync(string functionName, object result)
 		{
 			var query = "SELECT " +
 			            "	d.Id, " +
@@ -107,14 +106,14 @@ protected override bool AppliesTo(Dialect.Dialect dialect)
 			using (var session = OpenSession())
 			using (var transaction = session.BeginTransaction())
 			{
-				var results = await (session.CreateQuery(query).ListAsync(cancellationToken));
+				var results = await (session.CreateQuery(query).ListAsync());
 
 				Assert.That(results, Has.Count.EqualTo(1));
 				var tuple = results[0] as object[];
 				Assert.That(tuple, Is.Not.Null);
 				Assert.That(tuple, Has.Length.EqualTo(2));
 				Assert.That(tuple[1], Is.EqualTo(result));
-				await (transaction.CommitAsync(cancellationToken));
+				await (transaction.CommitAsync());
 			}
 		}
 	}

src/NHibernate.Test/Async/NHSpecificTest/NH2951/Fixture.cs

@@ -0,0 +1,62 @@
+//------------------------------------------------------------------------------
+// <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 NHibernate.Linq;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.NH2951
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class FixtureAsync : BugTestCase
+	{
+		protected override void OnTearDown()
+		{
+			using (ISession session = OpenSession())
+			using (ITransaction transaction = session.BeginTransaction())
+			{
+				session.Delete("from System.Object");
+
+				session.Flush();
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public async Task UpdateWithSubqueryToJoinedSubclassAsync()
+		{
+            using (ISession session = OpenSession())
+            using (ITransaction transaction = session.BeginTransaction())
+            {
+
+                var c = new Customer { Name = "Bob" };
+                await (session.SaveAsync(c));
+
+                var i = new Invoice { Amount = 10 };
+                await (session.SaveAsync(i));
+
+                await (session.FlushAsync());
+                await (transaction.CommitAsync());
+            }
+
+            using (ISession session = OpenSession())
+			using (session.BeginTransaction())
+			{
+                // Using (select c.Id ...) works.
+                string hql = "update Invoice i set i.Customer = (select c from Customer c where c.Name = 'Bob')";
+
+			    int result = await (session.CreateQuery(hql).ExecuteUpdateAsync());
+
+                Assert.AreEqual(1, result);
+			}
+		}
+	}
+}

src/NHibernate.Test/Async/NHSpecificTest/NH750/Fixture.cs

@@ -108,7 +108,7 @@ public async Task DeviceOfDriveAsync()
 				await (t.CommitAsync());
 			}
 
-			await (VerifyResultAsync(2,2,  msg: "modified collection"));
+			await (VerifyResultAsync(2, 2, msg: "modified collection"));
 
 			async Task VerifyResultAsync(int expectedInCollection, int expectedInDb, string msg)
 			{

src/NHibernate.Test/NHSpecificTest/NH2951/Fixture.cs

@@ -20,7 +20,6 @@ protected override void OnTearDown()
 		}
 
 		[Test]
-        [Ignore("Not working.")]
 		public void UpdateWithSubqueryToJoinedSubclass()
 		{
             using (ISession session = OpenSession())
@@ -49,4 +48,4 @@ public void UpdateWithSubqueryToJoinedSubclass()
 			}
 		}
 	}
-}
+}

src/NHibernate/Hql/Ast/ANTLR/Tree/FromElement.cs

@@ -505,7 +505,7 @@ public virtual string GetIdentityColumn()
 			{
 				propertyName = NHibernate.Persister.Entity.EntityPersister.EntityID;
 			}
-			if (Walker.StatementType == HqlSqlWalker.SELECT)
+			if (Walker.StatementType == HqlSqlWalker.SELECT || Walker.IsSubQuery)
 			{
 				cols = GetPropertyMapping(propertyName).ToColumns(table, propertyName);
 			}