Gnus changes encoding of attachment

Gnus changes encoding of attachment

[Peter Münster]

Hi,

Is it normal, that Gnus changes the encoding of my attachment from
ISO-8859 (on my hard-disk) to UTF-8 (in the message)?

Here an example: http://article.gmane.org/gmane.linux.vdr/47034

Is it a bug, configuration problem or something else?

TIA for any hints,
-- 
           Peter

Re: Gnus changes encoding of attachment

[Katsumi Yamaoka]

Peter Münster wrote:
> Is it normal, that Gnus changes the encoding of my attachment from
> ISO-8859 (on my hard-disk) to UTF-8 (in the message)?

By default Gnus never prefers a certain encoding.  What chooses
it is Emacs, that works according to its hard-coded rules,
the language-environment[1] or the locale[2].  But Gnus offers
you a means to change the behavior.  Try this:

(setq mm-coding-system-priorities '(iso-8859-1))

The value should be a list of coding-systems[3] you prefer.  See
the Info[4] for more detail.  Note that iso-8859-1 won't be used
if there's a character that cannot be encoded by iso-8859-1 in a
message.

[1] See the value of the variable: current-language-environment
[2] `M-! locale RET' and see the buffer "*Shell Command Output*".
[3] The symbols used for the coding-system names are normally
    the same as the ones used for the encoding names in Emacs.
[4] (info "(Emacs-MIME)Encoding Customization") <- Type C-x C-e.

Re: Gnus changes encoding of attachment

[Peter Münster]

On Tue, Feb 12 2013, Katsumi Yamaoka wrote:

> the language-environment[1] or the locale[2].  But Gnus offers
> you a means to change the behavior.  Try this:
>
> (setq mm-coding-system-priorities '(iso-8859-1))

Ok, I understand now: since the attachment is of type text, it must be
in the same encoding as the message body (always utf-8 for me).

So if I want to send an attachment without any modification, I have to
change the type to "application/octet-stream". Then, it works.

Thanks,
-- 
           Peter