From: Jani Nikula <jani@nikula.org>
To: "Jan N. Klug" <jan.n.klug@rub.de>, notmuch@notmuchmail.org
Subject: Re: [PATCH 2/3] notmuch-mutt: support for messages that
	lack	Message-ID	headers
In-Reply-To: <20150124165639.GA1316@mobil-13.rubion.rub.de>
References: <1422090701-19385-1-git-send-email-zack@upsilon.cc>
	<1422090701-19385-3-git-send-email-zack@upsilon.cc>
	<871tmkql6j.fsf@nikula.org> <20150124152106.GA23037@upsilon.cc>
	<20150124165639.GA1316@mobil-13.rubion.rub.de>
User-Agent: Notmuch/0.19+37~g290dc80 (http://notmuchmail.org) Emacs/24.4.1
	(x86_64-pc-linux-gnu)
Date: Sat, 24 Jan 2015 22:04:20 +0200
Message-ID: <87y4ososhn.fsf@nikula.org>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: list

On Sat, 24 Jan 2015, "Jan N. Klug" <jan.n.klug@rub.de> wrote:
> On Sat, Jan 24, 2015 at 04:21:06PM +0100, Stefano Zacchiroli wrote:
>> On Sat, Jan 24, 2015 at 04:59:16PM +0200, Jani Nikula wrote:
>> > On Sat, 24 Jan 2015, Stefano Zacchiroli <zack@upsilon.cc> wrote:
>> > > To do the above, rewrite get_message_id() to scan the current message
>> > > line by line, incrementally computing a SHA1. As a consequence, drop
>> > > the dependency on Mail::Internet.
>> > 
>> > I am not so sure this is a good idea however, see below.
>> [...]
>> But I didn't think of header folding, and you're absolutely correct in
>> saying that might be a problem.
>
> I disagree. I do not think that header folding is a problem here. RFC
> 5322 and RFC 2822 state that FWS in the message-id are not allowed (as
> opposed to In-Reply: and other headers, where FWS may occur between, but
> not inside message-ids).

Not *inside* message-ids, but as a data point, 0.05% of my email have
FWS *before* the message-id. That's more than the amount of messages
I have without a message-id.

BR,
Jani.