Adding additional case

lib/MySQL_Session.cpp

@@ -4243,6 +4243,11 @@ void MySQL_Session::MySQL_Stmt_Result_to_MySQL_wire(MYSQL_STMT *stmt, MySQL_Conn
 }
 
 void MySQL_Session::MySQL_Result_to_MySQL_wire(MYSQL *mysql, MySQL_ResultSet *MyRS, MySQL_Data_Stream *_myds) {
+        if (mysql == NULL) {
+                // error
+                client_myds->myprot.generate_pkt_ERR(true,NULL,NULL,client_myds->pkt_sid+1, 2013, (char *)"HY000" ,(char *)"Lost connection to MySQL server during query");
+                return;
+        }
 	if (MyRS) {
 		assert(MyRS->result);
 		bool transfer_started=MyRS->transfer_started;