On Fri, 16 Dec 2011 17:01:04 +0100, Olivier Berger <olivier.berger@it-sudparis.eu> wrote:

> In my understanding, the quoted-printable iso-8859-1 is correct for
> french accents, and is converted somehow to UTF-8, though it is
> displayed in an emacs buffer that looks like iso-8859-1 (The
> minibuffer separator line starts with '-1:%*-' ...

Do you the same behaviour with "emacs -q"?

I did the following: 

$ export LANG=fr_FR.utf8
$ export LC_CTYPE=fr_FR.utf8
$ emacs -q  # gtk emacs

M-x notmuch

and your message id:"877h1wv7mg.fsf@inf-8657.int-evry.fr" displays fine
(with U in the modeline).

Poking around at random, I did 

       M-x set-language-environment <Return> French <Return>

and then I could duplicate your problem; the mode line shows 8859-1
coding system and the message is not displayed correctly. On the other
hand, in this case the patch I sent does fix the actual message display
for me, just as it did in the other case where I set the locale directly
to fr_FR (without utf8).


d