HHH-7849 Unable to join on an embedded field

hibernate-core/src/main/java/org/hibernate/hql/internal/ast/tree/ComponentJoin.java

@@ -57,7 +57,8 @@ public class ComponentJoin extends FromElement {
 		fromClause.addJoinByPathMap( componentPath, this );
 		initializeComponentJoin( new ComponentFromElementType( this ) );
 
-		this.columns = origin.getPropertyMapping( "" ).toColumns( getTableAlias(), componentProperty );
+		String[] cols = origin.getPropertyMapping( "" ).toColumns( getTableAlias(), componentProperty );
+		this.columns = cols.length == 0 ? new String[] { null} : cols;
 		StringBuilder buf = new StringBuilder();
 		for ( int j = 0; j < columns.length; j++ ) {
 			final String column = columns[j];

hibernate-core/src/test/java/org/hibernate/test/component/basic2/Component.java

@@ -0,0 +1,39 @@
+package org.hibernate.test.component.basic2;
+
+
+import javax.persistence.*;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * {@inheritDoc}
+ *
+ * @author Mathieu Grenonville
+ */
+@Entity
+public class Component {
+
+    @Id
+	private Long id;
+    @Embedded
+	private Component.Emb emb;
+
+	public Component() {
+	}
+
+    @Access(AccessType.FIELD)
+    @Embeddable
+    public static class Emb {
+
+        @OneToMany(targetEntity = Stuff.class)
+        Set<Stuff> stuffs = new HashSet<Stuff>();
+
+        @Entity
+        public static class Stuff {
+            @Id
+            private Long id;
+        }
+    }
+
+
+}

hibernate-core/src/test/java/org/hibernate/test/component/basic2/ComponentJoinsTest.java

@@ -23,6 +23,7 @@
  */
 package org.hibernate.test.component.basic2;
 
+import org.hibernate.testing.TestForIssue;
 import org.junit.Test;
 
 import org.hibernate.Session;
@@ -36,7 +37,7 @@ import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
 public class ComponentJoinsTest extends BaseCoreFunctionalTestCase {
 	@Override
 	public Class[] getAnnotatedClasses() {
-		return new Class[] { Person.class };
+		return new Class[]{Person.class, Component.class, Component.Emb.Stuff.class};
 	}
 
 	@Test
@@ -45,14 +46,27 @@ public class ComponentJoinsTest extends BaseCoreFunctionalTestCase {
 		Session session = openSession();
 		session.beginTransaction();
 		// use it in WHERE
-		session.createQuery( "select p from Person p join p.name as n where n.lastName like '%'" ).list();
+		session.createQuery("select p from Person p join p.name as n where n.lastName like '%'").list();
 		// use it in SELECT
-		session.createQuery( "select n.lastName from Person p join p.name as n" ).list();
-		session.createQuery( "select n from Person p join p.name as n" ).list();
+		session.createQuery("select n.lastName from Person p join p.name as n").list();
+		session.createQuery("select n from Person p join p.name as n").list();
 		// use it in ORDER BY
-		session.createQuery( "select n from Person p join p.name as n order by n.lastName" ).list();
-		session.createQuery( "select n from Person p join p.name as n order by p" ).list();
-		session.createQuery( "select n from Person p join p.name as n order by n" ).list();
+		session.createQuery("select n from Person p join p.name as n order by n.lastName").list();
+		session.createQuery("select n from Person p join p.name as n order by p").list();
+		session.createQuery("select n from Person p join p.name as n order by n").list();
+		session.getTransaction().commit();
+		session.close();
+	}
+
+	@Test
+	@TestForIssue(jiraKey = "HHH-7849")
+	public void testComponentJoins_HHH_7849() {
+		// Just checking proper query construction and syntax checking via database query parser...
+		Session session = openSession();
+		session.beginTransaction();
+		// use it in WHERE
+		session.createQuery("select c from Component c join c.emb as e where e.stuffs is empty ").list();
+
 		session.getTransaction().commit();
 		session.close();
 	}