Fix entity join for entity with discriminator (#2464)

Author: bahusoid

src/NHibernate.Test/Async/NHSpecificTest/GH2463/Fixture.cs

@@ -0,0 +1,41 @@
+//------------------------------------------------------------------------------
+// <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.DomainModel;
+using NUnit.Framework;
+using NHibernate.Linq;
+
+namespace NHibernate.Test.NHSpecificTest.GH2463
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class FixtureAsync : TestCase
+	{
+		protected override string[] Mappings
+		{
+			get { return new[] {"ABC.hbm.xml"}; }
+		}
+
+		[Test]
+		public async Task CanJoinOnEntityWithDiscriminatorAsync()
+		{
+			using (var s = OpenSession())
+			{
+				await (s.Query<A>().Join(
+					s.Query<A>(),
+					a => a.Id,
+					b => b.Id,
+					(a, b) =>
+						new {a, b}).ToListAsync());
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2463/Fixture.cs

@@ -0,0 +1,29 @@
+using System.Linq;
+using NHibernate.DomainModel;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH2463
+{
+	[TestFixture]
+	public class Fixture : TestCase
+	{
+		protected override string[] Mappings
+		{
+			get { return new[] {"ABC.hbm.xml"}; }
+		}
+
+		[Test]
+		public void CanJoinOnEntityWithDiscriminator()
+		{
+			using (var s = OpenSession())
+			{
+				s.Query<A>().Join(
+					s.Query<A>(),
+					a => a.Id,
+					b => b.Id,
+					(a, b) =>
+						new {a, b}).ToList();
+			}
+		}
+	}
+}

src/NHibernate/Hql/Ast/ANTLR/HqlSqlWalker.cs

@@ -794,8 +794,7 @@ private IQueryable ResolveEntityJoinReferencedPersister(IASTNode path)
 			if (path.Type == IDENT)
 			{
 				var pathIdentNode = (IdentNode) path;
-				string name = path.Text ?? pathIdentNode.OriginalText;
-				return SessionFactoryHelper.FindQueryableUsingImports(name);
+				return SessionFactoryHelper.FindQueryableUsingImports(pathIdentNode.Path);
 			}
 			else if (path.Type == DOT)
 			{