HHH-14148 fix issue mapping order SQL fragment could produce incorrect SQL

hibernate-core/src/main/antlr/sql-gen.g

@@ -146,7 +146,7 @@ selectStatement
 		from
 		( #(WHERE { out(" where "); } whereExpr ) )?
 		( #(GROUP { out(" group by "); } groupExprs ( #(HAVING { out(" having "); } booleanExpr[false]) )? ) )?
-		( #(ORDER { out(" order by "); } orderExprs ) )?
+		( #(ORDER { out(" order by "); } orderBySqlFragmentOrExprs ) )?
 	)
 	;
 
@@ -191,6 +191,11 @@ whereClauseExpr
 	| booleanExpr[ false ]
 	;
 
+orderBySqlFragmentOrExprs
+	: sqlToken // for the purpose of mapping-defined orderBy SQL fragment
+	| orderExprs
+	;
+
 orderExprs { String ordExp = null; String ordDir = null; String ordNul = null; }
 	// TODO: remove goofy space before the comma when we don't have to regression test anymore.
 	// Dialect is provided a hook to render each ORDER BY element, so the expression is being captured instead of
@@ -277,7 +282,7 @@ distinctOrAll
 	;
 
 countExpr
-	// Syntacitic predicate resolves star all by itself, avoiding a conflict with STAR in expr.
+	// Syntactic predicate resolves star all by itself, avoiding a conflict with STAR in expr.
 	: ROW_STAR { out("*"); }
 	| simpleExpr
 	;

hibernate-core/src/test/java/org/hibernate/test/annotations/onetomany/OrderByTest.java

@@ -24,15 +24,17 @@ import org.hibernate.Criteria;
 import org.hibernate.Hibernate;
 import org.hibernate.NullPrecedence;
 import org.hibernate.Session;
+import org.hibernate.cfg.AvailableSettings;
+import org.hibernate.cfg.Configuration;
 import org.hibernate.dialect.H2Dialect;
 import org.hibernate.dialect.MySQLDialect;
 import org.hibernate.dialect.Oracle8iDialect;
 import org.hibernate.dialect.SQLServer2008Dialect;
-import org.hibernate.dialect.SQLServer2012Dialect;
-import org.hibernate.dialect.SQLServerDialect;
 import org.hibernate.engine.spi.SessionImplementor;
+import org.hibernate.graph.RootGraph;
 import org.hibernate.persister.collection.CollectionPersister;
 import org.hibernate.persister.collection.QueryableCollection;
+import org.hibernate.query.Query;
 import org.hibernate.sql.SimpleSelect;
 import org.hibernate.testing.RequiresDialect;
 import org.hibernate.testing.TestForIssue;
@@ -515,6 +517,28 @@ public class OrderByTest extends BaseCoreFunctionalTestCase {
 		s.close();
 	}
 
+	@Test
+	@TestForIssue( jiraKey = "HHH-14148" )
+	@RequiresDialect(value = { H2Dialect.class, MySQLDialect.class, SQLServer2008Dialect.class },
+			comment = "By default H2 places NULL values first, so testing 'NULLS LAST' expression. " +
+					"For MySQL and SQL Server 2008 testing overridden Dialect#renderOrderByElement(String, String, String, NullPrecedence) method. " +
+					"MySQL and SQL Server 2008 does not support NULLS FIRST / LAST syntax at the moment, so transforming the expression to 'CASE WHEN ...'.")
+	public void testNullPrecedenceWithOrderBySqlFragment() {
+		inTransaction( session -> {
+			final RootGraph<Order> graph = session.createEntityGraph( Order.class );
+			graph.addAttributeNodes( "itemList" );
+
+			Query<Order> query = session.createQuery( "from Order", Order.class );
+			query.applyFetchGraph( graph );
+			query.getResultList(); // before HHH-14148 is fixed, incorrect SQL would be generated ending with " nulls last nulls last"
+		} );
+	}
+
+	@Override
+	protected void configure(Configuration configuration) {
+		configuration.setProperty( AvailableSettings.DEFAULT_NULL_ORDERING, "last" );
+	}
+
 	@Override
 	protected Class[] getAnnotatedClasses() {
 		return new Class[] {