Testsuite: tidy use of undef'd var

diff --git a/test/runtest b/test/runtest
index 64a8e7f3720a9c9e1d735e09050fe590642a3eed..8d96e13bda5f65f9d77b2657e5c1cd9bbe8af9b5 100755 (executable)
--- a/test/runtest
+++ b/test/runtest
@@ -4072,7 +4072,7 @@ DIR: for (my $i = 0; $i < @test_dirs; $i++)
        if (!defined $1 && $? != 0 || defined $1 && $? == 0) {
          $wantthis = 0;
          unlink("$parm_cwd/test-config");
-         $_ = "$1feature $2";
+         $_ = $1 || "" . "feature $2";
          last;
        }
        unlink("$parm_cwd/test-config");