Sometimes messages have an empty In-Reply-To header which throws
threaders off. This actually causes public-inbox-httpd to die,
which is probably bad and will be fixed elsewhere.
my ($hdr) = @_;
my $irt = $hdr->header_raw('In-Reply-To');
my ($hdr) = @_;
my $irt = $hdr->header_raw('In-Reply-To');
- return mid_clean($irt) if (defined $irt);
+ return mid_clean($irt) if defined $irt && $irt ne '';
my $refs = $hdr->header_raw('References');
if ($refs && $refs =~ /<([^>]+)>\s*\z/s) {
my $refs = $hdr->header_raw('References');
if ($refs && $refs =~ /<([^>]+)>\s*\z/s) {