Fix for NH3455.

Author: jlevitt

src/NHibernate.Test/NHSpecificTest/NH3455/Fixture.cs

@@ -81,7 +81,6 @@ public void OrderBySpecifiedPropertyWithCriteria()
 			using (var session = OpenSession())
 			using (session.BeginTransaction())
 			{
-				PersonDto dto = null;
 				var selectList = Projections.ProjectionList()
 				                            .Add(Projections.Property("Id"), "Id")
 				                            .Add(Projections.Property("Name"), "Name")

src/NHibernate/Loader/Criteria/CriteriaQueryTranslator.cs

@@ -815,7 +815,14 @@ public string[] GetColumnAliasesUsingProjection(ICriteria subcriteria, string pr
 		{
 			//first look for a reference to a projection alias
 			IProjection projection = rootCriteria.Projection;
-			string[] projectionColumns = projection == null ? null : projection.GetColumnAliases(propertyName, 0);
+			string[] projectionColumns = null;
+
+			if (projection != null)
+			{
+				projectionColumns = projection is IEnhancedProjection
+					? ((IEnhancedProjection)projection).GetColumnAliases(propertyName, 0, subcriteria, this)
+					: projection.GetColumnAliases(propertyName, 0);
+			}
 
 			if (projectionColumns == null)
 			{