fix uninitialized value warnings

I suspect these are only triggered by spammers.

diff --git a/IkiWiki/Plugin/comments.pm b/IkiWiki/Plugin/comments.pm
index 833bedf25dcbad59a6f1dc3faed0f5c764b03db9..6d0e45a97d29f49569f306b616aada1183f36510 100644 (file)
--- a/IkiWiki/Plugin/comments.pm
+++ b/IkiWiki/Plugin/comments.pm
@@ -406,19 +406,19 @@ sub sessioncgi ($$) {
 
        if ($config{comments_allowauthor}) {
                my $author = $form->field('author');
-               if (length $author) {
+               if (defined $author && length $author) {
                        $author =~ s/"/"/g;
                        $content .= " claimedauthor=\"$author\"\n";
                }
                my $url = $form->field('url');
-               if (length $url) {
+               if (defined $url && length $url) {
                        $url =~ s/"/"/g;
                        $content .= " url=\"$url\"\n";
                }
        }
 
        my $subject = $form->field('subject');
-       if (length $subject) {
+       if (defined $subject && length $subject) {
                $subject =~ s/"/"/g;
                $content .= " subject=\"$subject\"\n";
        }