Comment 4 for bug 266572

This bug is still valid, but the patch is incomplete at best.

Preliminary testing shows that with the patch, rebuilding the archive with bin/arch --wipe works generally as expected, but individual posts without In-Reply-To: headers are still not threaded by Subject if the list has a subject_prefix. This appears to be the case whether or not the prefix is included in the reply as sent. The posts are unthreaded in the archive until the archive is rebuilt with bin/arch --wipe.