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Date: Tue, 3 Nov 2020 23:59:42 +0000
From: Eric Wong <e@80x24.org>
To: Andrey Melnikov <temnota.am@gmail.com>
Cc: meta@public-inbox.org
Subject: Re: [PATCH] nntp: delimit Newsgroup: header with commas
Message-ID: <20201103235942.GA6163@dcvr>
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Andrey Melnikov <temnota.am@gmail.com> wrote:
> This break filtering on my leafnode.

OK, thanks for that info.

> What about "Path:" header?

Ah, oops; missed that.  I put "y" there since I figured it
wouldn't matter for leafnode (but only lightly tested it).

Since we don't have any NNTP propagation path, I guess putting
just server-name there is appropriate? (not yet deployed)

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 783c0076..cb095bca 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -415,10 +415,6 @@ sub set_nntp_headers ($$) {
 	my ($hdr, $smsg) = @_;
 	my ($mid) = $smsg->{mid};
 
-	# why? leafnode requires a Path: header for some inexplicable
-	# reason.  We'll fake the shortest one possible.
-	$hdr->header_set('Path', 'y');
-
 	# leafnode (and maybe other NNTP clients) have trouble dealing
 	# with v2 messages which have multiple Message-IDs (either due
 	# to our own content-based dedupe or buggy git-send-email versions).
@@ -438,11 +434,14 @@ sub set_nntp_headers ($$) {
 	$hdr->header_set('Xref', $xref);
 
 	# RFC 5536 3.1.4
-	my $newsgroups = (split(/ /, $xref, 2))[1]; # drop server name
+	my ($server_name, $newsgroups) = split(/ /, $xref, 2);
 	$newsgroups =~ s/:[0-9]+\b//g; # drop NNTP article numbers
 	$newsgroups =~ tr/ /,/;
 	$hdr->header_set('Newsgroups', $newsgroups);
 
+	# required for leafnode (RFC 5536 3.1.5)
+	$hdr->header_set('Path', $server_name);
+
 	header_append($hdr, 'List-Post', "<mailto:$ibx->{-primary_address}>");
 	if (my $url = $ibx->base_url) {
 		$mid = mid_escape($mid);