branches/5.1:

Swap the order in which mysql_thd, mysql_query_str and *mysql_query_str
are checked for non-NULL.

Suggested by:	Marko

row/row0sel.c

@@ -3577,9 +3577,9 @@ row_search_for_mysql(
 
 	if (trx->isolation_level <= TRX_ISO_READ_COMMITTED
 	    && prebuilt->select_lock_type != LOCK_NONE
+	    && trx->mysql_thd != NULL
 	    && trx->mysql_query_str != NULL
-	    && *trx->mysql_query_str != NULL
-	    && trx->mysql_thd != NULL) {
+	    && *trx->mysql_query_str != NULL) {
 
 		/* Scan the MySQL query string; check if SELECT is the first
 		word there */