if (defined($lock)) {
my $key = $r_hdr->{'Cancel-Key'} || return "$descr of $target without Cancel-Key";
#return verify_cancel_key($key, $lock, ' target=' . $target);
if (defined($lock)) {
my $key = $r_hdr->{'Cancel-Key'} || return "$descr of $target without Cancel-Key";
#return verify_cancel_key($key, $lock, ' target=' . $target);