And maybe 8-headered ones, too...
I noticed --reindex failing on the linux-renesas-soc mirror due
one 3-headed monster of a message having 3 sets of headers;
while another normal message had a Message-ID that matched one
of the 3 IDs of the 3-headed monster.
We still try to do the majority of indexing backwards, but we
defer indexing multi-Message-ID'd messages until the end to
ensure we get all the "good" messages in before we process the
multi-headered ones.
Link: https://public-inbox.org/meta/20191016211415.GA6084@dcvr/