avoid length in boolean context

Perl does not currently optimize for this.

ref (from p5p):
http://mid.gmane.org/D5C27970-9176-4C7A-8B99-7D78360E67A2@pobox.com

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/PublicInbox/Search.pm b/lib/PublicInbox/Search.pm
index 4362a002..4b3830e2 100644
--- a/lib/PublicInbox/Search.pm
+++ b/lib/PublicInbox/Search.pm
@@ -251,10 +251,11 @@ sub subject_summary {
                         last if length($new) >= $max;
                         $subj = $new;
                 }
-                if (length $subj) {
+                if ($subj ne '') {
                         my $r = scalar @subj ? ' ...' : '';
                         $subj =~ s/ \z/$r/s;
                 } else {
+                        # subject has one REALLY long word, and NOT spam? wtf
                         @subj = ($l =~ /\A(.{1,72})/);
                         $subj = $subj[0] . ' ...';
                 }