MW-369 FK fixes

Skipping wsrep extra FK checking for applier and replayer threads

storage/innobase/row/row0upd.cc

@@ -2267,7 +2267,7 @@ row_upd_clust_rec_by_insert(
 			}
 		}
 #ifdef WITH_WSREP
-		if (!referenced                                              &&
+		if (wsrep_on(trx->mysql_thd) && !referenced                  &&
 		    !(parent && que_node_get_type(parent) == QUE_NODE_UPDATE &&
 		      ((upd_node_t*)parent)->cascade_node == node)           &&
 		    foreign
@@ -2532,10 +2532,11 @@ row_upd_del_mark_clust_rec(
 			node, pcur, index->table, index, offsets, thr, mtr);
 	}
 #ifdef WITH_WSREP
-	if (err == DB_SUCCESS && !referenced                         &&
+	trx_t* trx = thr_get_trx(thr) ;
+
+	if (err == DB_SUCCESS && !referenced && trx && wsrep_on(trx->mysql_thd) &&
 	    !(parent && que_node_get_type(parent) == QUE_NODE_UPDATE &&
 	      ((upd_node_t*)parent)->cascade_node == node)           &&
-	    thr_get_trx(thr)                                         &&
 	    foreign
 	) {
 		err = wsrep_row_upd_check_foreign_constraints(

storage/xtradb/row/row0upd.cc

@@ -1984,7 +1984,9 @@ row_upd_sec_index_entry(
 					index, offsets, thr, &mtr);
 			}
 #ifdef WITH_WSREP
-			if (err == DB_SUCCESS && !referenced                  &&
+			if (wsrep_on(trx->mysql_thd)                          &&
+			    !wsrep_thd_is_BF(trx->mysql_thd, FALSE)           &&
+			    err == DB_SUCCESS && !referenced                  &&
 			    !(parent && que_node_get_type(parent) ==
 				QUE_NODE_UPDATE                               &&
 			      ((upd_node_t*)parent)->cascade_node == node)    &&
@@ -2273,7 +2275,7 @@ row_upd_clust_rec_by_insert(
 			}
 		}
 #ifdef WITH_WSREP
-		if (!referenced                                              &&
+		if (wsrep_on(trx->mysql_thd) && !referenced                  &&
 		    !(parent && que_node_get_type(parent) == QUE_NODE_UPDATE &&
 		      ((upd_node_t*)parent)->cascade_node == node)           &&
 		    foreign
@@ -2541,10 +2543,11 @@ row_upd_del_mark_clust_rec(
 			node, pcur, index->table, index, offsets, thr, mtr);
 	}
 #ifdef WITH_WSREP
-	if (err == DB_SUCCESS && !referenced                         &&
+	trx_t* trx = thr_get_trx(thr) ;
+
+	if (err == DB_SUCCESS && !referenced && trx && wsrep_on(trx->mysql_thd) &&
 	    !(parent && que_node_get_type(parent) == QUE_NODE_UPDATE &&
 	      ((upd_node_t*)parent)->cascade_node == node)           &&
-	    thr_get_trx(thr)                                         &&
 	    foreign
 	) {
 		err = wsrep_row_upd_check_foreign_constraints(