MW-402 cascading FK issue (5.7 version)

Optimizing cascade node list traversal, which could turn out as
performance bottleneck
Even this current cascade node check could be skipped, but a dedicated
mtr test is needed to confirm that

storage/innobase/row/row0upd.cc

@@ -2430,6 +2430,10 @@ row_upd_sec_index_entry(
 		if (!rec_get_deleted_flag(
 			    rec, dict_table_is_comp(index->table))) {
 
+#ifdef WITH_WSREP
+			que_node_t *parent = que_node_get_parent(node);
+#endif /* WITH_WSREP */
+
 			err = btr_cur_del_mark_set_sec_rec(
 				flags, btr_cur, TRUE, thr, &mtr);
 
@@ -2437,10 +2441,9 @@ row_upd_sec_index_entry(
 				break;
 			}
 #ifdef WITH_WSREP
-			if (!referenced && foreign &&
-			    wsrep_on(trx->mysql_thd) &&
-			    !wsrep_thd_is_BF(trx->mysql_thd, FALSE) &&
-				wsrep_must_process_fk(node, trx)) {
+			if (!referenced && foreign
+			    && wsrep_must_process_fk(node, trx)
+			    && !wsrep_thd_is_BF(trx->mysql_thd, FALSE)) {
 				ulint*	offsets = rec_get_offsets(
 					rec, index, NULL, ULINT_UNDEFINED,
 					&heap);
@@ -2659,6 +2662,9 @@ row_upd_clust_rec_by_insert(
 	rec_t*		rec;
 	ulint*		offsets			= NULL;
 
+#ifdef WITH_WSREP
+	que_node_t *parent = que_node_get_parent(node);
+#endif /* WITH_WSREP */
 	ut_ad(node);
 	ut_ad(dict_index_is_clust(index));
 
@@ -2752,6 +2758,7 @@ row_upd_clust_rec_by_insert(
 			err = wsrep_row_upd_check_foreign_constraints(
 				node, pcur, table, index, offsets, thr, mtr);
 
+
 			switch (err) {
 			case DB_SUCCESS:
 			case DB_NO_REFERENCED_ROW:
@@ -2964,6 +2971,10 @@ row_upd_del_mark_clust_rec(
 	ut_ad(dict_index_is_clust(index));
 	ut_ad(node->is_delete);
 
+#ifdef WITH_WSREP
+	que_node_t *parent = que_node_get_parent(node);
+#endif /* WITH_WSREP */
+
 	pcur = node->pcur;
 	btr_cur = btr_pcur_get_btr_cur(pcur);
 
@@ -2992,6 +3003,7 @@ row_upd_del_mark_clust_rec(
 	} else if (trx && wsrep_on(trx->mysql_thd)  &&
 		   wsrep_must_process_fk(node, trx)) {
 
+
 		err = wsrep_row_upd_check_foreign_constraints(
 			node, pcur, index->table, index, offsets, thr, mtr);