Fix ConditionalProjection GetType from outer query

src/NHibernate.Test/Async/NHSpecificTest/GH2454/FixtureByCode.cs

@@ -0,0 +1,130 @@
+//------------------------------------------------------------------------------
+// <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.MappingSchema;
+using NHibernate.Criterion;
+using NHibernate.Mapping.ByCode;
+using NHibernate.SqlCommand;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH2454
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class ByCodeFixtureAsync : TestCaseMappingByCode
+	{
+		protected override bool AppliesTo(Dialect.Dialect dialect)
+		{
+			return dialect.SupportsScalarSubSelects;
+		}
+
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.Class<Project>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+			});
+
+			mapper.Class<Component>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+				rc.ManyToOne(x => x.Project, m => { m.Column("ProjectId"); m.NotNullable(true); });
+			});
+
+			mapper.Class<Tag>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+				rc.ManyToOne(x => x.Component1, m => { m.Column("Component1Id"); m.NotNullable(true); });
+				rc.ManyToOne(x => x.Component2, m => { m.Column("Component2Id"); m.NotNullable(false); });
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				// alpha entities
+				var projectAlpha = new Project {Name = "Alpha"};
+				session.Save(projectAlpha);
+
+				var componentAlpha = new Component {Project = projectAlpha, Name = "Thingie"};
+				session.Save(componentAlpha);
+
+				var tagAlpha = new Tag {Component1 = componentAlpha, Name = "A20"};
+				session.Save(tagAlpha);
+
+				// beta entities
+				var projectBeta = new Project {Name = "Beta"};
+				session.Save(projectBeta);
+
+				var componentBeta = new Component {Project = projectBeta, Name = "Thingie"};
+				session.Save(componentBeta);
+
+				var tagBeta = new Tag {Component1 = componentBeta, Name = "B17"};
+				session.Save(tagBeta);
+
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.CreateQuery("delete from Tag").ExecuteUpdate();
+				session.CreateQuery("delete from Component").ExecuteUpdate();
+				session.CreateQuery("delete from Project").ExecuteUpdate();
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public async Task SubqueryCorrelatedThroughConditionalAsync()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var tagCriteria = session.CreateCriteria(typeof(Tag), "t");
+				tagCriteria.CreateCriteria("Component1", "c1");
+				tagCriteria.CreateCriteria("Component2", "c2", JoinType.LeftOuterJoin);
+
+				// create correlated subquery
+				var projectCriteria = DetachedCriteria.For(typeof(Project), "p");
+
+				var conditionalCorrelationProjection = Projections.Conditional(
+					Restrictions.IsNotNull(Projections.Property("t.Component2")),
+					Projections.Property("c2.Project"),
+					Projections.Property("c1.Project"));
+				projectCriteria.Add(Restrictions.EqProperty("p.Id", conditionalCorrelationProjection));
+
+				projectCriteria.SetProjection(Projections.Property("p.Name"));
+
+				var projectNameProjection = Projections.SubQuery(projectCriteria);
+
+				tagCriteria.Add(Restrictions.Eq(projectNameProjection, "Beta"));
+				tagCriteria.SetProjection(Projections.Property("t.Name"));
+
+				// run query
+				var results = await (tagCriteria.ListAsync());
+
+				Assert.That(results, Is.EquivalentTo(new[] {"B17"}));
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2454/Domain.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH2454
+{
+	public class Project
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+	}
+
+	public class Component
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+		public virtual Project Project { get; set; }
+	}
+
+	public class Tag
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+		public virtual Component Component1 { get; set; }
+		public virtual Component Component2 { get; set; }
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH2454/FixtureByCode.cs

@@ -0,0 +1,119 @@
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Criterion;
+using NHibernate.Mapping.ByCode;
+using NHibernate.SqlCommand;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH2454
+{
+	[TestFixture]
+	public class ByCodeFixture : TestCaseMappingByCode
+	{
+		protected override bool AppliesTo(Dialect.Dialect dialect)
+		{
+			return dialect.SupportsScalarSubSelects;
+		}
+
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.Class<Project>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+			});
+
+			mapper.Class<Component>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+				rc.ManyToOne(x => x.Project, m => { m.Column("ProjectId"); m.NotNullable(true); });
+			});
+
+			mapper.Class<Tag>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+				rc.ManyToOne(x => x.Component1, m => { m.Column("Component1Id"); m.NotNullable(true); });
+				rc.ManyToOne(x => x.Component2, m => { m.Column("Component2Id"); m.NotNullable(false); });
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				// alpha entities
+				var projectAlpha = new Project {Name = "Alpha"};
+				session.Save(projectAlpha);
+
+				var componentAlpha = new Component {Project = projectAlpha, Name = "Thingie"};
+				session.Save(componentAlpha);
+
+				var tagAlpha = new Tag {Component1 = componentAlpha, Name = "A20"};
+				session.Save(tagAlpha);
+
+				// beta entities
+				var projectBeta = new Project {Name = "Beta"};
+				session.Save(projectBeta);
+
+				var componentBeta = new Component {Project = projectBeta, Name = "Thingie"};
+				session.Save(componentBeta);
+
+				var tagBeta = new Tag {Component1 = componentBeta, Name = "B17"};
+				session.Save(tagBeta);
+
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.CreateQuery("delete from Tag").ExecuteUpdate();
+				session.CreateQuery("delete from Component").ExecuteUpdate();
+				session.CreateQuery("delete from Project").ExecuteUpdate();
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public void SubqueryCorrelatedThroughConditional()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var tagCriteria = session.CreateCriteria(typeof(Tag), "t");
+				tagCriteria.CreateCriteria("Component1", "c1");
+				tagCriteria.CreateCriteria("Component2", "c2", JoinType.LeftOuterJoin);
+
+				// create correlated subquery
+				var projectCriteria = DetachedCriteria.For(typeof(Project), "p");
+
+				var conditionalCorrelationProjection = Projections.Conditional(
+					Restrictions.IsNotNull(Projections.Property("t.Component2")),
+					Projections.Property("c2.Project"),
+					Projections.Property("c1.Project"));
+				projectCriteria.Add(Restrictions.EqProperty("p.Id", conditionalCorrelationProjection));
+
+				projectCriteria.SetProjection(Projections.Property("p.Name"));
+
+				var projectNameProjection = Projections.SubQuery(projectCriteria);
+
+				tagCriteria.Add(Restrictions.Eq(projectNameProjection, "Beta"));
+				tagCriteria.SetProjection(Projections.Property("t.Name"));
+
+				// run query
+				var results = tagCriteria.List();
+
+				Assert.That(results, Is.EquivalentTo(new[] {"B17"}));
+			}
+		}
+	}
+}

src/NHibernate/Loader/Criteria/CriteriaQueryTranslator.cs

@@ -778,18 +778,8 @@ public IType GetTypeUsingProjection(ICriteria subcriteria, string propertyName)
 
 			if (projectionTypes == null)
 			{
-					//it does not refer to an alias of a projection,
-					//look for a property
-
-				if (TryGetType(subcriteria, propertyName, out var type))
-				{
-					return type;
-				}
-				if (outerQueryTranslator != null)
-				{
-					return outerQueryTranslator.GetTypeUsingProjection(subcriteria, propertyName);
-				}
-				throw new QueryException("Could not find property " + propertyName);
+				//it does not refer to an alias of a projection, look for a property
+				return GetType(subcriteria, propertyName);
 			}
 			else
 			{
@@ -804,10 +794,13 @@ public IType GetTypeUsingProjection(ICriteria subcriteria, string propertyName)
 
 		public IType GetType(ICriteria subcriteria, string propertyName)
 		{
-			if(!TryParseCriteriaPath(subcriteria, propertyName, out var entityName, out var entityPropName, out _))
-				throw new QueryException("Could not find property " + propertyName);
+			if (TryGetType(subcriteria, propertyName, out var resultType))
+				return resultType;
+
+			if (outerQueryTranslator != null)
+				return outerQueryTranslator.GetType(subcriteria, propertyName);
 
-			return GetPropertyMapping(entityName).ToType(entityPropName);
+			throw new QueryException("Could not find property " + propertyName);
 		}
 
 		public bool TryGetType(ICriteria subcriteria, string propertyName, out IType type)