From: Michal Sojka <sojkam1@fel.cvut.cz>
To: Jani Nikula <jani@nikula.org>, Damien Cassou <damien@cassou.me>,
 David Bremner <david@tethera.net>, notmuch@notmuchmail.org
Subject: Re: notmuch-reply doesn't use Reply-To
In-Reply-To: <87twnygmps.fsf@nikula.org>
References: <8737vjcx9b.fsf@cassou.me> <8737vi8l7j.fsf@zancas.localnet>
 <87fuzi9ng5.fsf@cassou.me> <87twnygmps.fsf@nikula.org>
User-Agent: Notmuch/0.21+30~g55c056a (http://notmuchmail.org) Emacs/24.5.1
 (x86_64-pc-linux-gnu)
Date: Tue, 29 Dec 2015 22:54:45 +0100
Message-ID: <8760zgdioq.fsf@steelpick.2x.cz>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: list

Hi all,

On Fri, Dec 04 2015, Jani Nikula wrote:
> On Fri, 04 Dec 2015, Damien Cassou <damien@cassou.me> wrote:
>> David Bremner <david@tethera.net> writes:
>>
>>> Damien Cassou <damien@cassou.me> writes:
>>>
>>>>                    "To" : "rmod@inria.fr",
>>>>                    "Reply-To" : "rmod@inria.fr",
>>>>                    "From" : "seaside@rmod.inria.fr",
>>>>                    "Subject" : "[rmod] [Mm10s] 2015-11-30",
>>>>                    "Date" : "Mon, 30 Nov 2015 07:00:01 +0100"
>>>
>>> A quick look at the code suggests this is falling victim to the
>>> "reply-to munging" detection code, which considers a reply-to field
>>> redudant if it duplicates one of the other fields. From the source
>>>
>>>     /* Some mailing lists munge the Reply-To header despite it being A Bad
>>>      * Thing, see http://www.unicom.com/pw/reply-to-harmful.html
>>>      *
>>>      * The munging is easy to detect, because it results in a
>>>      * redundant reply-to header, (with an address that already exists
>>>      * in either To or Cc). So in this case, we ignore the Reply-To
>>>      * field and use the From header. This ensures the original sender
>>>      * will get the reply even if not subscribed to the list. Note
>>>      * that the address in the Reply-To header will always appear in
>>>      * the reply.
>>>      */
>>
>>
>> The last sentence seems to contradict my example:
>>
>>     Note that the address in the Reply-To header will always appear in
>>     the reply.
>>
>> Here is the reply message, and it does not contain the address in Reply-To.
>
> This was true way back when notmuch reply only knew about reply all. For
> --reply-to=sender, it's broken. The simplest "fix" might be

I don't think that this is broken for two reasons:

1. In tests/T230-reply-to-sender.sh, there is "Un-munging Reply-To"
   test, which checks the same combination of headers as in Damien's
   case and uses --reply-to=sender. The test passes and the reply has
   To=From.

2. When replying to mailing lists using reply-to munging, current
   notmuch behavior allows me to decide whether to reply 1) privately to
   the mail sender (--reply-to=sender) or 2) to the mailing list
   (--reply-to=all). The proposed change would make option 1) harder.

Therefore I suggest to fix this by applying the documentation patch from
the follow-up mail.

-Michal