ext/File-Glob/t/rt131211.t: fix timing issues

This test file occasionally fails test numbers 1 and/or 2 on smokes.
These two tests measure how long it takes to do a matching and
non-matching glob() with a lot of "a*a*a*...." and fail if the
match and non-matching times differ too much (the original bug was that
non-match went exponential on number of "a*"'s).

However, on good systems, the timings returned are typically
sub-millisecond, so I'm guessing the occasional failures are due to

(small measured noise) * 100  > (another small measured noise).

So this commit avoids tests 1&2 failing unless the values measured
are large enough not to be merely noise.

This is just speculation on my part though - I couldn't reproduce a
failure myself.

1 files changed, 10 insertions, 3 deletions

diff --git a/ext/File-Glob/t/rt131211.t b/ext/File-Glob/t/rt131211.t
index ed1b321f1d..4ac0d8729d 100644
--- a/ext/File-Glob/t/rt131211.t
+++ b/ext/File-Glob/t/rt131211.t
@@ -1,3 +1,8 @@
+# tests for RT 131211
+#
+# non-matching glob("a*a*a*...") went exponential time on number of a*'s
+
+
 use strict;
 use warnings;
 use v5.16.0;
@@ -49,14 +54,16 @@ while (++$count < 10) {
     $elapsed_fail -= time;
     @no_files= glob catfile $path, "x".("a*" x $count) . "c";
     $elapsed_fail += time;
-    last if $elapsed_fail > $elapsed_match * 100;
+    last if $elapsed_fail > ($elapsed_match < 0.2 ? 0.2 : $elapsed_match) * 100;
 }
 
 is $count,10,
-    "tried all the patterns without bailing out";
+    "tried all the patterns without bailing out"
+    or diag("elapsed_match=$elapsed_match elapsed_fail=$elapsed_fail");
 
 SKIP: {
-    skip "unstable timing", 1 unless $elapsed_match && $elapsed_fail;
+    skip "unstable  or too small timing", 1 unless
+            $elapsed_match >= 0.001 && $elapsed_fail >= 0.001;
     ok $elapsed_fail <= 10 * $elapsed_match,
         "time to fail less than 10x the time to match"
         or diag("elapsed_match=$elapsed_match elapsed_fail=$elapsed_fail");