Galera MTR Tests: Modify mysqltest so that if a --let = `SELECT ...` query is...

Galera MTR Tests: Modify mysqltest so that if a --let = `SELECT ...` query is interrupted, the test does not fail but the error is communicated to caller

client/mysqltest.cc

@@ -2678,7 +2678,7 @@ void var_query_set(VAR *var, const char *query, const char** query_end)
   init_dynamic_string(&ds_query, 0, (end - query) + 32, 256);
   do_eval(&ds_query, query, end, FALSE);
 
-  if (mysql_real_query(mysql, ds_query.str, ds_query.length)) 
+  if (mysql_real_query(mysql, ds_query.str, ds_query.length) || !(res= mysql_store_result(mysql)))
   {
     handle_error(curr_command, mysql_errno(mysql), mysql_error(mysql),
                  mysql_sqlstate(mysql), &ds_res);
@@ -2688,13 +2688,6 @@ void var_query_set(VAR *var, const char *query, const char** query_end)
     DBUG_VOID_RETURN;
   }
   
-  if (!(res= mysql_store_result(mysql)))
-  {
-    report_or_die("Query '%s' didn't return a result set", ds_query.str);
-    dynstr_free(&ds_query);
-    eval_expr(var, "", 0);
-    DBUG_VOID_RETURN;
-  }
   dynstr_free(&ds_query);
 
   if ((row= mysql_fetch_row(res)) && row[0])

mysql-test/include/wait_condition.inc

@@ -39,7 +39,7 @@ let $wait_timeout= 0;
 let $wait_condition_reps= 0;
 while ($wait_counter)
 {
-    --error 0,ER_NO_SUCH_TABLE,ER_LOCK_WAIT_TIMEOUT,ER_UNKNOWN_COM_ERROR
+    --error 0,ER_NO_SUCH_TABLE,ER_LOCK_WAIT_TIMEOUT,ER_UNKNOWN_COM_ERROR,ER_LOCK_DEADLOCK
     let $success= `$wait_condition`;
     inc $wait_condition_reps;
     if ($success)