HHH-7849 Cleaner fix. Added additional regression test.

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

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

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

@@ -174,11 +174,12 @@ public class IdentNode extends FromReferenceNode implements SelectExpression {
 					}
 					setText( joinedFragment );
 				}
+				return true;
 			}
-			else {
+			else if ( columnExpressions.length > 0 ) {
 				setText( columnExpressions[0] );
+				return true;
 			}
-			return true;
 		}
 		return false;
 	}

hibernate-entitymanager/src/test/java/org/hibernate/jpa/test/criteria/components/ComponentCriteriaTest.java

@@ -25,6 +25,7 @@ package org.hibernate.jpa.test.criteria.components;
 
 import java.util.List;
 import javax.persistence.EntityManager;
+import javax.persistence.TypedQuery;
 import javax.persistence.criteria.CriteriaBuilder;
 import javax.persistence.criteria.CriteriaQuery;
 import javax.persistence.criteria.Root;
@@ -64,6 +65,17 @@ public class ComponentCriteriaTest extends BaseEntityManagerFunctionalTestCase {
 		Assert.assertEquals( 1, list.size() );
 		em.getTransaction().commit();
 		em.close();
+		
+		// HHH-5792
+		em = getOrCreateEntityManager();
+		em.getTransaction().begin();
+		TypedQuery< Client > q = em.createQuery(
+				"SELECT c FROM Client c JOIN c.name n WHERE n.firstName = '"
+						+ client.getName().getFirstName() + "'",
+                 Client.class );
+		Assert.assertEquals( 1, q.getResultList().size() );
+		em.getTransaction().commit();
+		em.close();
 
 		em = getOrCreateEntityManager();
 		em.getTransaction().begin();