+sub header_append ($$$) {
+ my ($hdr, $k, $v) = @_;
+ my @v = $hdr->header($k);
+ foreach (@v) {
+ return if $v eq $_;
+ }
+ $hdr->header_set($k, @v, $v);
+}
+
+sub set_nntp_headers {
+ my ($hdr, $ng, $n, $mid) = @_;
+
+ # clobber some
+ $hdr->header_set('Newsgroups', $ng->{newsgroup});
+ $hdr->header_set('Xref', xref($ng, $n));
+ header_append($hdr, 'List-Post', "<mailto:$ng->{-primary_address}>");
+ if (my $url = $ng->base_url) {
+ $mid = mid_escape($mid);
+ header_append($hdr, 'Archived-At', "<$url$mid/>");
+ header_append($hdr, 'List-Archive', "<$url>");
+ }
+}
+