comments: avoid warning if there's no subject

diff --git a/IkiWiki/Plugin/comments.pm b/IkiWiki/Plugin/comments.pm
index 6bd18a5cf2be10765a5dbbf5bf83fbd1a88c80bf..d1105b3662ab4b6e96720bc86b9f512e5565f267 100644 (file)
--- a/IkiWiki/Plugin/comments.pm
+++ b/IkiWiki/Plugin/comments.pm
@@ -434,8 +434,10 @@ sub sessioncgi ($$) { #{{{
        }
 
        my $subject = $form->field('subject');
-       $subject =~ s/"/"/g;
-       $content .= " subject=\"$subject\"\n";
+       if (length $subject) {
+               $subject =~ s/"/"/g;
+               $content .= " subject=\"$subject\"\n";
+       }
 
        $content .= " date=\"" . IkiWiki::formattime(time, '%X %x') . "\"\n";