SemanticQueryBuilder#visitPathExpression() cannot cast DomainPathPart to SqmExpression

hibernate-core/src/main/java/org/hibernate/query/hql/internal/DomainPathPart.java

@@ -29,6 +29,10 @@ public class DomainPathPart implements SemanticPathPart {
 		assert currentPath != null;
 	}
 
+	SqmExpression<?> getSqmExpression() {
+		return currentPath;
+	}
+
 	@Override
 	public SemanticPathPart resolvePathPart(
 			String name,

hibernate-core/src/main/java/org/hibernate/query/hql/internal/SemanticQueryBuilder.java

@@ -1158,7 +1158,12 @@ public class SemanticQueryBuilder<R> extends HqlParserBaseVisitor<Object> implem
 
 	@Override
 	public SqmExpression<?> visitPathExpression(HqlParser.PathExpressionContext ctx) {
-		return (SqmExpression<?>) ctx.path().accept( this );
+		final HqlParser.PathContext path = ctx.path();
+		final Object accept = path.accept( this );
+		if ( accept instanceof DomainPathPart ) {
+			return ( (DomainPathPart) accept ).getSqmExpression();
+		}
+		return (SqmExpression<?>) accept;
 	}
 
 	@Override

hibernate-core/src/test/java/org/hibernate/orm/test/query/sqm/exec/SubQueryImplicitJoinReferenceTest.java

@@ -61,6 +61,17 @@ public class SubQueryImplicitJoinReferenceTest {
         } );
     }
 
+    @Test
+    public void performHqlIsNullTest(SessionFactoryScope scope) {
+        // Now simulate running an audit query
+        scope.inSession( session -> {
+            session.createQuery( "select e__ FROM TheEntity e__ "
+                                         + "WHERE e__.originalId.rev.id = (select max(e2__.originalId.rev.id) FROM "
+                                         + "TheEntity e2__ WHERE " +
+                                         "e2__.originalId.rev is null)" ).list();
+        } );
+    }
+
     @Test
     public void performHqlTest2(SessionFactoryScope scope) {
         // Now simulate running an audit query