On Tue, 2016-03-29 at 21:06 +1100, Stephen Rothwell wrote:

Hi Jeremy,

On Tue, 29 Mar 2016 16:56:58 +0800 Jeremy Kerr [off-list ref] wrote:

quoted

From the mail that Anton has sent to linuxppc-dev:

quoted

From: Anton Blanchard via Linuxppc-dev <redacted>
Reply-To: Anton Blanchard [off-list ref]  

Do you know why mailman would be re-writing From: there? It's confusing
patchwork, as multiple mails are now coming from that address.

Yep, Anton posts from samba.org.  They publish a DMARC policy that
breaks mailing lists.  The best thing we can do is to do the above
rewrite of the From header.

The alternative is that all our Yahoo, Gmail and Hotmail subscribers
(at least) would bounce the email.

So this rewriting will happen for any From: line that has an address
that has such a DMARC policy.  We have had posts from Yahoo subscribers
bounced in the past.

[adding patchwork list to cc]

So it sounds like this is just something we're going to have to live with.

It's causing problems on patchwork because patchwork only uses the email
address to lookup a user. This is causing patches to be misattributed on
ozlabs.org, eg:

  http://patchwork.ozlabs.org/project/linuxppc-dev/list/?submitter=68366&state=*

Paul was the first person to have a From header rewritten, eg to:

  From: Paul Mackerras via Linuxppc-dev [off-list ref]

And so in the patchwork database the user "linuxppc-dev@lists.ozlabs.org" has a
name of "Paul Mackerras via Linuxppc-dev".

The subsequent two patches (ppc4xx-rng and perf jit) are from different people,
who also had their From address rewritten due to DMARC.

So I think patchwork needs to:
 - detect mails that have been rewritten due to DMARC
   - AFAICS the only way to do this is to notice that the From address is the
     same as the list address.
 - when it sees those mails, use the Reply-To header instead.

cheers