BUG: trouble with forwarding with accents

[Antoine Beaupré]

So I have an accent in my family name, as you can see from the From
header here. This has a tendency of finding the greatest and finest
UTF-8 bug, and often no one believes me because they don't have that
interesting property.

Notmuch has been bugging me with such a problem for ages now. When I
forward a mail, the accents in my name (or in the signature inserted)
are broken. (Interstingly, I haven't *actually* been bothered by that
bug for a while because I was using Emacs through an SSH console. Now,
I'm using Emacs within a X11 terminal instead, "GNU Emacs 24.4.1
(x86_64-pc-linux-gnu, GTK+ Version 3.14.5) of 2015-03-07 on trouble,
modified by Debian".)

Interestingly, piping that buffer into patebinit doesn't yield any errors:

http://paste.debian.net/378776/

Yet there is clearly an issue while writing the buffer, as you can see
on this screenshot:

http://paste.anarc.at/snap-2016.02.05-17.28.30.png

Look at the buffer on the bottom: my accent (a é) is all busted
in the From line, even though it is perfectly fine in *this* buffer. If
I try to send that message (say to the `devnull` recipient), I get a
nasty warning:

```
These default coding systems were tried to encode text
in the buffer `1454711375.18796_680127_47.angela':
  (utf-8-unix (21 . 4194243) (22 . 4194217))
However, each of them encountered characters it couldn't encode:
  utf-8-unix cannot encode these: \303 \251

Click on a character (or switch to this window by `C-x o'
and select the characters by RET) to jump to the place it appears,
where `C-u C-x =' will give information about it.

Select one of the safe coding systems listed below,
or cancel the writing with C-g and edit the buffer
   to remove or modify the problematic characters,
or specify any other coding system (and risk losing
   the problematic characters).

  raw-text no-conversion
```

(Note that I rewrote the actual escape characters above to avoid to be
"backslash number number number" instead of the actual escape sequence
to avoid trouble, as I am sending this through emacs as well.)

I usually [PLOKTA][1] my way through that warning, but I have no idea if
the recipient receives something that is jumbled up or not. Besides,
PLOKTA is not fun, I just feel like I look like this:

http://i1.kym-cdn.com/photos/images/original/000/234/765/b7e.jpg

 [1]: https://en.wikipedia.org/wiki/PLOKTA

This sure smells like double-encoding. Is this notmuch's fault or
message-mode, and how can i fix this stuff?

This is notmuch 0.18 in Debian jessie.

Thanks for any advice,

A.

-- 
Code is law.
                         - Lawrence Lessig