tests/backref-multibyte-slow:: avoid false positive

* tests/backref-multibyte-slow: When redirecting the "fast" LC_ALL=C
run's output to /dev/null, we got an artificially low timing (of 0),
due to grep's own stdout-vs-/dev/null optimization.  With an initial
timing of 0 on that first run, the derived timeout for the UTF-8 run
(which redirects to a file) would be a mere 1 second.  The fix: also
redirect that first run's output to a file, not to /dev/null.

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/backref-multibyte-slow b/tests/backref-multibyte-slow
index d447a4a9..05bb62e1 100755
--- a/tests/backref-multibyte-slow
+++ b/tests/backref-multibyte-slow
@@ -14,7 +14,7 @@ $AWK 'BEGIN {for (i=0; i<13000; i++) print "aba"}' /dev/null > in || fail=1
 # when running in en_US.UTF-8.  Round up to whole seconds, since timeout
 # can't deal with fractional seconds.
 max_seconds=$(LC_ALL=C perl -le 'use Time::HiRes qw(time); my $s = time();
-              system q,grep -E '\''^([a-z]).\1$'\'' in > /dev/null,;
+              system q,grep -E '\''^([a-z]).\1$'\'' in > junk,;
               my $elapsed = time() - $s; print int (1 + 10 * $elapsed)') \
   || { max_seconds=5;
        warn_ "$ME_: warning: no perl? using default of 5s timeout"; }