NH-3973 - Remove dependency on passed enabledFilters parameter from SubqueryExpression.ToSqlString method

Author: hazzik

src/NHibernate/Criterion/SubqueryExpression.cs

@@ -7,6 +7,7 @@
 using NHibernate.Persister.Entity;
 using NHibernate.SqlCommand;
 using NHibernate.Type;
+using NHibernate.Util;
 
 namespace NHibernate.Criterion
 {
@@ -60,10 +61,9 @@ public override SqlString ToSqlString(ICriteria criteria, ICriteriaQuery criteri
 
 			IOuterJoinLoadable persister = (IOuterJoinLoadable) factory.GetEntityPersister(criteriaImpl.EntityOrClassName);
 
-			//patch to generate joins on subqueries
-			//stolen from CriteriaLoader
-			CriteriaJoinWalker walker =
-				new CriteriaJoinWalker(persister, innerQuery, factory, criteriaImpl, criteriaImpl.EntityOrClassName, enabledFilters);
+			criteriaImpl.Session = DeriveRootSession(criteria);
+
+			var walker = new CriteriaJoinWalker(persister, innerQuery, factory, criteriaImpl, criteriaImpl.EntityOrClassName, criteriaImpl.Session.EnabledFilters);
 
 			parameters = innerQuery.GetQueryParameters(); // parameters can be inferred only after initialize the walker
 
@@ -99,6 +99,7 @@ public override SqlString ToSqlString(ICriteria criteria, ICriteriaQuery criteri
 			return buf.ToSqlString();
 		}
 
+
 		public override string ToString()
 		{
 			if (prefixOp)
@@ -117,10 +118,22 @@ public override IProjection[] GetProjections()
 			return null;
 		}
 
-		public ICriteria Criteria
+		// NH-1146
+		public ICriteria Criteria => criteriaImpl;
+
+		static ISessionImplementor DeriveRootSession(ICriteria criteria)
 		{
-			// NH-1146
-			get { return criteriaImpl; }
+			while (criteria is CriteriaImpl.Subcriteria subcriteria)
+			{
+				criteria = subcriteria.Parent;
+			}
+			if (criteria is CriteriaImpl criteriaImpl)
+			{
+				return criteriaImpl.Session;
+			}
+			// could happen for custom Criteria impls.  Not likely, but...
+			// for long term solution, see HHH-3514
+			return null;
 		}
 	}
 }