HHH-9342 - HQL "x member of treat(y as Type).collections" fails to parse

hibernate-core/src/main/antlr/hql.g

@@ -593,7 +593,7 @@ relationalExpression
 					#l.setText( (n == null) ? "like" : "not like");
 				}
 				concatenation likeEscape)
-			| (MEMBER! (OF!)? p:path! {
+			| (MEMBER! (OF!)? p:memberOfPath! {
 				processMemberOf(n,#p,currentAST);
 			  } ) )
 		)
@@ -612,6 +612,14 @@ betweenList
 	: concatenation AND! concatenation
 	;
 
+memberOfPath
+	// JPA says this is a `collection_valued_path_expression` which is essentially either:
+	// 		1) a treated path followed by a collection-valued attribute reference
+	//		2) a path
+	: { validateSoftKeyword("treat") && LA(2) == OPEN }? i:IDENT! OPEN! p:path AS! a:path! CLOSE! ( DOT^ path )
+	| path
+	;
+
 //level 4 - string concatenation
 concatenation
 	: additiveExpression 

hibernate-core/src/test/java/org/hibernate/test/hql/TreatKeywordTest.java

@@ -0,0 +1,85 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.test.hql;
+
+import java.util.List;
+
+import org.hibernate.Query;
+import org.hibernate.Session;
+
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+import org.junit.Test;
+
+import static junit.framework.TestCase.assertEquals;
+
+/**
+ * Tests the "treat" keyword in HQL.
+ *
+ * @author Etienne Miret
+ * @author Steve Ebersole
+ *
+ * @see org.hibernate.test.jpa.ql.TreatKeywordTest
+ */
+public class TreatKeywordTest extends BaseCoreFunctionalTestCase {
+
+	@Override
+	public String[] getMappings() {
+		return new String[] { "hql/Animal.hbm.xml" };
+	}
+
+	@Test
+	@TestForIssue( jiraKey = "HHH-9342" )
+	public void memberOfTreatTest() {
+		// prepare test data
+		Session s = openSession();
+		s.getTransaction().begin();
+
+		Human owner = new Human();
+		s.persist( owner );
+
+		Dog wildDog = new Dog();
+		s.persist( wildDog );
+
+		Dog petDog = new Dog();
+		petDog.setOwner( owner );
+		s.persist( petDog );
+
+		Cat petCat = new Cat();
+		petCat.setOwner( owner );
+		s.persist( petCat );
+
+		s.getTransaction().commit();
+		s.close();
+
+
+		// perform test
+		s = openSession();
+		s.getTransaction().begin();
+		Query q = s.createQuery(
+				"select pet" +
+						" from Animal pet, Animal owner" +
+						" where pet member of treat (owner as Human).pets"
+		);
+		@SuppressWarnings("unchecked")
+		List<Animal> results = q.list();
+		assertEquals( 2, results.size() );
+		s.getTransaction().commit();
+		s.close();
+
+
+		// clean up test data
+		s = openSession();
+		s.getTransaction().begin();
+		s.delete( petCat );
+		s.delete( petDog );
+		s.delete( wildDog );
+		s.delete( owner );
+		s.getTransaction().commit();
+		s.close();
+	}
+}