searchidx: use defined for checking EOF behavior

While empty or "0" should never appear, this allows the
reviewer to think and know less about the context in which
this check is done.

diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index 67272997b22149faf3db8b9018a86ac8569f83ae..1d0d926f28164a29a904643bdc0cacdc7218fc22 100644 (file)
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -337,7 +337,7 @@ sub rlog {
                                --raw -r --no-abbrev/, $range);
        my $latest;
        my $bytes;
-       while (my $line = <$log>) {
+       while (defined(my $line = <$log>)) {
                if ($line =~ /$addmsg/o) {
                        my $mime = do_cat_mail($git, $1, \$bytes) or next;
                        $add_cb->($self, $git, $mime, $bytes);