nntp+www: drop List-* and Archived-At headers

These headers can conflict with headers in the DKIM signature;
and parsing the DKIM-Signature header to determine whether or
not we can safely add a header would be more code and CPU
cycles.

Since IMAP seems fine without these headers (and JMAP will
likely be, too), there's likely no need to continue appending
these to every message.  Nowadays, developers seem sufficiently
trained to use URLs with Message-IDs in them.  So drop the
headers and save some cycles and bandwidth all around.

1 files changed, 6 insertions, 26 deletions

diff --git a/lib/PublicInbox/Mbox.pm b/lib/PublicInbox/Mbox.pm
index c88350c9..c8e4b406 100644
--- a/lib/PublicInbox/Mbox.pm
+++ b/lib/PublicInbox/Mbox.pm
@@ -20,7 +20,7 @@ sub getline {
         my $ibx = $ctx->{ibx};
         my $eml = $ibx->smsg_eml($smsg) or return;
         my $n = $ctx->{smsg} = $ibx->over->next_by_mid(@{$ctx->{next_arg}});
-        $ctx->zmore(msg_hdr($ctx, $eml, $smsg->{mid}));
+        $ctx->zmore(msg_hdr($ctx, $eml));
         if ($n) {
                 $ctx->translate(msg_body($eml));
         } else { # last message
@@ -46,7 +46,7 @@ sub async_eml { # for async_blob_cb
         # next message
         $ctx->{smsg} = $ctx->{ibx}->over->next_by_mid(@{$ctx->{next_arg}});
 
-        $ctx->zmore(msg_hdr($ctx, $eml, $smsg->{mid}));
+        $ctx->zmore(msg_hdr($ctx, $eml));
         $ctx->{http_out}->write($ctx->translate(msg_body($eml)));
 }
 
@@ -74,7 +74,7 @@ sub no_over_raw ($) {
         my $mref = $ctx->{ibx}->msg_by_mid($ctx->{mid}) or return;
         my $eml = PublicInbox::Eml->new($mref);
         [ 200, res_hdr($ctx, $eml->header_str('Subject')),
-                [ msg_hdr($ctx, $eml, $ctx->{mid}) . msg_body($eml) ] ]
+                [ msg_hdr($ctx, $eml) . msg_body($eml) ] ]
 }
 
 # /$INBOX/$MESSAGE_ID/raw
@@ -90,8 +90,8 @@ sub emit_raw {
         $ctx->psgi_response(200, $res_hdr);
 }
 
-sub msg_hdr ($$;$) {
-        my ($ctx, $eml, $mid) = @_;
+sub msg_hdr ($$) {
+        my ($ctx, $eml) = @_;
         my $header_obj = $eml->header_obj;
 
         # drop potentially confusing headers, ssoma already should've dropped
@@ -99,31 +99,11 @@ sub msg_hdr ($$;$) {
         foreach my $d (qw(Lines Bytes Content-Length Status)) {
                 $header_obj->header_set($d);
         }
-        my $ibx = $ctx->{ibx};
-        my $base = $ctx->{base_url};
-        $mid = $ctx->{mid} unless defined $mid;
-        $mid = mid_escape($mid);
-        my @append = (
-                'Archived-At', "<$base$mid/>",
-                'List-Archive', "<$base>",
-        );
         my $crlf = $header_obj->crlf;
         my $buf = $header_obj->as_string;
         # fixup old bug from import (pre-a0c07cba0e5d8b6a)
         $buf =~ s/\A[\r\n]*From [^\r\n]*\r?\n//s;
-        $buf = "From mboxrd\@z Thu Jan  1 00:00:00 1970" . $crlf . $buf;
-
-        for (my $i = 0; $i < @append; $i += 2) {
-                my $k = $append[$i];
-                my $v = $append[$i + 1];
-                my @v = $header_obj->header_raw($k);
-                $buf .= "$k: $v$crlf" if !grep(/\A\Q$v\E\z/, @v);
-        }
-        my $post_addr = $ibx->{-primary_address};
-        if ($post_addr && $header_obj->header_raw('List-Post')) {
-                $buf .= "List-Post: <mailto:$post_addr>$crlf";
-        }
-        $buf .= $crlf;
+        "From mboxrd\@z Thu Jan  1 00:00:00 1970" . $crlf . $buf . $crlf;
 }
 
 sub msg_body ($) {