Re: vger doesn't like UTF-8 from send-email

From: Michael Witten <mfwitten@gmail.com>
Date: Jun 13, 2010, 04:15 UTC
Message-ID: <AANLkTim1QajqLOp4y6-oIMAGp8Tkf7z9uTH6bwIIFYkH@mail.gmail.com>
In-Reply-To: <201006121211.12870.trast@student.ethz.ch>

On Sat, Jun 12, 2010 at 05:11, Thomas Rast <trast@student.ethz.ch> wrote:

Show 13 quoted lines

> AFAICT the original message did not declare an encoding:
>
> Subject: [PATCH v2 0/2] bash completion: Support "divergence from upstream" warnings in __git_ps1
> Date: Sat, 12 Jun 2010 12:02:14 +0200
> Message-ID: <cover.1276336602.git.trast@student.ethz.ch>
> X-Mailer: git-send-email 1.7.1.561.g94582
> In-Reply-To: <20100612000002.GA30196@neumann>
> References: <20100612000002.GA30196@neumann>
> MIME-Version: 1.0
> Content-Type: text/plain
> Return-Path: trast@student.ethz.ch
> ...
> Is this a new vger policy, or am I hitting a send-email bug?

Let's assume the headers themselves are already properly encoded.

According to:

    http://www.faqs.org/rfcs/rfc2045.html

we have:

    The proper Content-Transfer-Encoding
    label must always be used.

and:

    An encoding type of 7BIT requires that
    the body is already in a 7bit mail-ready
    representation.  This is the default value
    -- that is, "Content-Transfer-Encoding: 7BIT"
    is assumed if the Content-Transfer-Encoding
    header field is not present.

Moreover, according to:

    http://www.faqs.org/rfcs/rfc2046.html

we have:

    4.1.2    Charset Parameter
    ...
    The default character set, which must be
    assumed in the absence of a charset parameter,
    is US-ASCII.

So, your email is indeed incorrect in 2 ways if the body contains UTF-8 encoded data.

>From what I've skimmed, the mail user agent (MUA)---such as

send-email---could send your unmodified message body by producing these headers:

    MIME-Version: 1.0
    Content-type: text/plain; charset=utf-8
    Content-transfer-encoding: 8bit

but only 7bit transfer encodings are guaranteed to make it intact to the destination; consequently, it would probably be a good idea for the MUA to transform your message into some 7bit encoding, preferably a human-readable one such as the 'quoted-printable' encoding; after such a transformation, the headers could be:

    MIME-Version: 1.0
    Content-type: text/plain; charset=utf-8
    Content-transfer-encoding: quoted-printable

Sincerely, Michael Witten