Fix possible ERROR log when parsing join in hql

src/NHibernate.Test/Associations/OneToOneFixture.cs

@@ -3,6 +3,7 @@
 using NHibernate.Cfg.MappingSchema;
 using NHibernate.Mapping.ByCode;
 using NHibernate.Test.Associations.OneToOneFixtureEntities;
+using NHibernate.Util;
 using NUnit.Framework;
 
 namespace NHibernate.Test.Associations
@@ -127,19 +128,22 @@ public void OneToOneCompositeQueryOverCompareWithJoinById()
 				Assert.That(loadedEntity, Is.Not.Null);
 			}
 		}
-		
+
 		//GH-2064
 		[Test]
 		public void OneToOneCompositeQuerySelectProjection()
 		{
+			using(var logSpy = new LogSpy(typeof(ReflectHelper)))
 			using (var session = OpenSession())
 			{
 				var loadedProjection = session.Query<Parent>().Select(x => new {x.OneToOneComp, x.Key}).FirstOrDefault();
 
 				Assert.That(loadedProjection.OneToOneComp, Is.Not.Null);
+				// GH-2855 Error is logged
+				Assert.That(logSpy.GetWholeLog(), Is.Empty);
 			}
 		}
-		
+
 		//NH-3178 (GH-1125)
 		[Test]
 		public void OneToOneQueryOverSelectProjection()

src/NHibernate.Test/Async/Associations/OneToOneFixture.cs

@@ -13,6 +13,7 @@
 using NHibernate.Cfg.MappingSchema;
 using NHibernate.Mapping.ByCode;
 using NHibernate.Test.Associations.OneToOneFixtureEntities;
+using NHibernate.Util;
 using NUnit.Framework;
 using NHibernate.Linq;
 
@@ -139,19 +140,22 @@ public async Task OneToOneCompositeQueryOverCompareWithJoinByIdAsync()
 				Assert.That(loadedEntity, Is.Not.Null);
 			}
 		}
-		
+
 		//GH-2064
 		[Test]
 		public async Task OneToOneCompositeQuerySelectProjectionAsync()
 		{
+			using(var logSpy = new LogSpy(typeof(ReflectHelper)))
 			using (var session = OpenSession())
 			{
 				var loadedProjection = await (session.Query<Parent>().Select(x => new {x.OneToOneComp, x.Key}).FirstOrDefaultAsync());
 
 				Assert.That(loadedProjection.OneToOneComp, Is.Not.Null);
+				// GH-2855 Error is logged
+				Assert.That(logSpy.GetWholeLog(), Is.Empty);
 			}
 		}
-		
+
 		//NH-3178 (GH-1125)
 		[Test]
 		public async Task OneToOneQueryOverSelectProjectionAsync()

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

@@ -26,7 +26,7 @@ namespace NHibernate.Test.Hql
 	[TestFixture]
 	public class EntityJoinHqlTestAsync : TestCaseMappingByCode
 	{
-		private const string _customEntityName = "CustomEntityName";
+		private const string _customEntityName = "CustomEntityName.Test";
 		private EntityWithCompositeId _entityWithCompositeId;
 		private EntityWithNoAssociation _noAssociation;
 		private EntityCustomEntityName _entityWithCustomEntityName;
@@ -51,6 +51,46 @@ public async Task CanJoinNotAssociatedEntityAsync()
 			}
 		}
 
+		[Test]
+		public async Task CanJoinNotAssociatedEntityFullNameAsync()
+		{
+			using (var sqlLog = new SqlLogSpy())
+			using (var session = OpenSession())
+			{
+				EntityComplex entityComplex = 
+				await (session
+					.CreateQuery("select ex " +
+						"from EntityWithNoAssociation root " +
+						$"left join {typeof(EntityComplex).FullName} ex with root.Complex1Id = ex.Id")
+						.SetMaxResults(1)
+					.UniqueResultAsync<EntityComplex>());
+
+				Assert.That(entityComplex, Is.Not.Null);
+				Assert.That(NHibernateUtil.IsInitialized(entityComplex), Is.True);
+				Assert.That(sqlLog.Appender.GetEvents().Length, Is.EqualTo(1), "Only one SQL select is expected");
+			}
+		}
+
+		[Test]
+		public async Task CanJoinNotAssociatedInterfaceFullNameAsync()
+		{
+			using (var sqlLog = new SqlLogSpy())
+			using (var session = OpenSession())
+			{
+				EntityComplex entityComplex = 
+				await (session
+					.CreateQuery("select ex " +
+						"from EntityWithNoAssociation root " +
+						$"left join {typeof(IEntityComplex).FullName} ex with root.Complex1Id = ex.Id")
+						.SetMaxResults(1)
+					.UniqueResultAsync<EntityComplex>());
+
+				Assert.That(entityComplex, Is.Not.Null);
+				Assert.That(NHibernateUtil.IsInitialized(entityComplex), Is.True);
+				Assert.That(sqlLog.Appender.GetEvents().Length, Is.EqualTo(1), "Only one SQL select is expected");
+			}
+		}
+
 		[Test]
 		public async Task CanJoinNotAssociatedEntity_OnKeywordAsync()
 		{

src/NHibernate.Test/Hql/EntityJoinHqlTest.cs

@@ -14,7 +14,7 @@ namespace NHibernate.Test.Hql
 	[TestFixture]
 	public class EntityJoinHqlTest : TestCaseMappingByCode
 	{
-		private const string _customEntityName = "CustomEntityName";
+		private const string _customEntityName = "CustomEntityName.Test";
 		private EntityWithCompositeId _entityWithCompositeId;
 		private EntityWithNoAssociation _noAssociation;
 		private EntityCustomEntityName _entityWithCustomEntityName;
@@ -39,6 +39,46 @@ public void CanJoinNotAssociatedEntity()
 			}
 		}
 
+		[Test]
+		public void CanJoinNotAssociatedEntityFullName()
+		{
+			using (var sqlLog = new SqlLogSpy())
+			using (var session = OpenSession())
+			{
+				EntityComplex entityComplex = 
+				session
+					.CreateQuery("select ex " +
+						"from EntityWithNoAssociation root " +
+						$"left join {typeof(EntityComplex).FullName} ex with root.Complex1Id = ex.Id")
+						.SetMaxResults(1)
+					.UniqueResult<EntityComplex>();
+
+				Assert.That(entityComplex, Is.Not.Null);
+				Assert.That(NHibernateUtil.IsInitialized(entityComplex), Is.True);
+				Assert.That(sqlLog.Appender.GetEvents().Length, Is.EqualTo(1), "Only one SQL select is expected");
+			}
+		}
+
+		[Test]
+		public void CanJoinNotAssociatedInterfaceFullName()
+		{
+			using (var sqlLog = new SqlLogSpy())
+			using (var session = OpenSession())
+			{
+				EntityComplex entityComplex = 
+				session
+					.CreateQuery("select ex " +
+						"from EntityWithNoAssociation root " +
+						$"left join {typeof(IEntityComplex).FullName} ex with root.Complex1Id = ex.Id")
+						.SetMaxResults(1)
+					.UniqueResult<EntityComplex>();
+
+				Assert.That(entityComplex, Is.Not.Null);
+				Assert.That(NHibernateUtil.IsInitialized(entityComplex), Is.True);
+				Assert.That(sqlLog.Appender.GetEvents().Length, Is.EqualTo(1), "Only one SQL select is expected");
+			}
+		}
+
 		[Test]
 		public void CanJoinNotAssociatedEntity_OnKeyword()
 		{

src/NHibernate.Test/Hql/EntityJoinHqlTestEntities.cs

@@ -2,7 +2,17 @@
 
 namespace NHibernate.Test.Hql.EntityJoinHqlTestEntities
 {
-	public class EntityComplex
+	public interface IEntityComplex
+	{
+		Guid Id { get; set; }
+		int Version { get; set; }
+		string Name { get; set; }
+		string LazyProp { get; set; }
+		EntityComplex SameTypeChild { get; set; }
+		EntityComplex SameTypeChild2 { get; set; }
+	}
+
+	public class EntityComplex : IEntityComplex
 	{
 		public virtual Guid Id { get; set; }
 		public virtual int Version { get; set; }

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

@@ -702,12 +702,10 @@ void CreateFromJoinElement(
 			// 		2) an entity-join (join com.acme.User)
 			//
 			// so make the proper interpretation here...
-			var entityJoinReferencedPersister = ResolveEntityJoinReferencedPersister(path);
-			if (entityJoinReferencedPersister != null)
+			// DOT node processing was moved to prefer implicit join path before probing for entity join
+			if (path.Type == IDENT)
 			{
-				var entityJoin = CreateEntityJoin(entityJoinReferencedPersister, alias, joinType, with);
-				((FromReferenceNode) path).FromElement = entityJoin;
-				SetPropertyFetch(entityJoin, propertyFetch, alias);
+				ProcessAsEntityJoin();
 				return;
 			}
 			// The path AST should be a DotNode, and it should have been evaluated already.
@@ -725,6 +723,7 @@ void CreateFromJoinElement(
 
 			// Generate an explicit join for the root dot node.   The implied joins will be collected and passed up
 			// to the root dot node.
+			dot.SkipSemiResolve = true;
 			dot.Resolve( true, false, alias == null ? null : alias.Text );
 
 			FromElement fromElement;
@@ -738,7 +737,8 @@ void CreateFromJoinElement(
 				fromElement = dot.GetImpliedJoin();
 				if (fromElement == null)
 				{
-					throw new InvalidPathException("Invalid join: " + dot.Path);
+					ProcessAsEntityJoin();
+					return;
 				}
 				SetPropertyFetch(fromElement, propertyFetch, alias);
 
@@ -762,6 +762,15 @@ void CreateFromJoinElement(
 			{
 				log.Debug("createFromJoinElement() : {0}", _printer.ShowAsString( fromElement, "-- join tree --" ));
 			}
+
+			void ProcessAsEntityJoin()
+			{
+				var node = (FromReferenceNode) path;
+				var entityJoinReferencedPersister = ResolveEntityJoinReferencedPersister(node);
+				var entityJoin = CreateEntityJoin(entityJoinReferencedPersister, alias, joinType, with);
+				node.FromElement = entityJoin;
+				SetPropertyFetch(entityJoin, propertyFetch, alias);
+			}
 		}
 
 		private EntityJoinFromElement CreateEntityJoin(
@@ -790,42 +799,29 @@ private EntityJoinFromElement CreateEntityJoin(
 			return join;
 		}
 
-		private IQueryable ResolveEntityJoinReferencedPersister(IASTNode path)
+		private IQueryable ResolveEntityJoinReferencedPersister(FromReferenceNode path)
 		{
-			string entityName = GetEntityJoinCandidateEntityName(path);
+			string entityName = path.Path;
 
 			var persister = SessionFactoryHelper.FindQueryableUsingImports(entityName);
 			if (persister == null && entityName != null)
 			{
 				var implementors = SessionFactoryHelper.Factory.GetImplementors(entityName);
 				//Possible case - join on interface
 				if (implementors.Length == 1)
-					persister = SessionFactoryHelper.FindQueryableUsingImports(implementors[0]);
+					persister = (IQueryable) SessionFactoryHelper.Factory.TryGetEntityPersister(implementors[0]);
 			}
 
 			if (persister != null)
 				return persister;
 
 			if (path.Type == IDENT)
 			{
-				// Since IDENT node is not expected for implicit join path, we can throw on not found persister
 				throw new QuerySyntaxException(entityName + " is not mapped");
 			}
 
-			return null;
-		}
-
-		private static string GetEntityJoinCandidateEntityName(IASTNode path)
-		{
-			switch (path.Type)
-			{
-				case IDENT:
-					return ((IdentNode) path).Path;
-				case DOT:
-					return ASTUtil.GetPathText(path);
-			}
-
-			return null;
+			//Keep old exception for DOT node
+			throw new InvalidPathException("Invalid join: " + entityName);
 		}
 
 		private static string GetPropertyPath(DotNode dotNode, IASTNode alias)

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

@@ -124,6 +124,8 @@ public string PropertyPath
 			set { _propertyPath = value; }
 		}
 
+		internal bool SkipSemiResolve { get; set; }
+
 		public override void SetScalarColumnText(int i)
 		{
 			string[] sqlColumns = GetColumns();
@@ -200,7 +202,7 @@ public override void Resolve(bool generateJoin, bool implicitJoin, string classA
 			// this might be a Java constant.
 			if ( propertyType == null ) 
 			{
-				if ( parent == null ) 
+				if (parent == null && !SkipSemiResolve)
 				{
 					Walker.LiteralProcessor.LookupConstant( this );
 				}