Fix modrdn newSuperior checks

servers/slapd/back-bdb/modrdn.c

@@ -268,7 +268,7 @@ retry:	/* transaction retry */
 
 	new_parent_dn = &p_dn;	/* New Parent unless newSuperior given */
 
-	if ( newSuperior != NULL ) {
+	if ( newSuperior->bv_val != NULL ) {
 		Debug( LDAP_DEBUG_TRACE, 
 			"bdb_modrdn: new parent \"%s\" requested...\n",
 			newSuperior->bv_val, 0, 0 );

servers/slapd/back-ldbm/modrdn.c

@@ -281,7 +281,7 @@ ldbm_back_modrdn(
 
 	new_parent_dn = &p_dn;	/* New Parent unless newSuperior given */
 
-	if ( newSuperior != NULL ) {
+	if ( newSuperior->bv_val != NULL ) {
 #ifdef NEW_LOGGING
 		LDAP_LOG(( "backend", LDAP_LEVEL_DETAIL1,
 			"ldbm_back_modrdn: new parent \"%s\" requested\n",
@@ -314,7 +314,7 @@ ldbm_back_modrdn(
 		}
 	}
 
-	if ( newSuperior != NULL ) {
+	if ( newSuperior && newSuperior->bv_val != NULL ) {
 		/* newSuperior == entry being moved?, if so ==> ERROR */
 		/* Get Entry with dn=newSuperior. Does newSuperior exist? */