Bug#32078 - Excessive warnings: One can only use the --user switch

            if running as root

Every start of a server in the test suite raised that warning.

The cause was an unconditionla add of the --user option to the
server command line. Only the "root" user (effective user id == 0)
must use that option.

Added check for effective user id == 0 before adding --user.

Thanks to Magnus Svensson for the patch.

mysql-test/mysql-test-run.pl

@@ -3754,7 +3754,9 @@ sub mysqld_arguments ($$$$) {
   # When mysqld is run by a root user(euid is 0), it will fail
   # to start unless we specify what user to run as. If not running
   # as root it will be ignored, see BUG#30630
-  if (!(grep(/^--user/, @$extra_opt, @opt_extra_mysqld_opt))) {
+  my $euid= $>;
+  if (!$glob_win32 and $euid == 0 and
+      grep(/^--user/, @$extra_opt, @opt_extra_mysqld_opt) == 0) {
     mtr_add_arg($args, "%s--user=root");
   }