Re: What does `undecided' do for encoding text?

[Kenichi Handa <handa@m17n.org>]

In article <uocxatswu.fsf@gnu.org>, Eli Zaretskii <eliz@gnu.org> writes:

> > From: Kenichi Handa <handa@m17n.org>
> > CC: emacs-devel@gnu.org
> > Date: Tue, 10 Feb 2009 20:16:53 +0900
> > 
> > > This may have nothing to do with what the programmer did.  My use case
> > > was in Rmail: if the original message had non-ASCII text encoded with
> > > QP or B64, Rmail would (correctly) return `undecided' when it detects
> > > the message encoding.  Suppose you then edit the message and add
> > > non-ASCII characters as raw bytes, e.g. by base64-decode-region, and
> > > type "C-c C-c".  rmail-cease-edit now needs to encode the text and put
> > > it back into the mbox buffer, and the immediate choice it has for the
> > > pertinent coding-system is to use buffer-file-coding-system of the
> > > buffer where the message was edited.  But the value of
> > > buffer-file-coding-system in that buffer is `undecided'...
> > 
> > The situation is the same as visiting an ASCII only file,
> > entering some non-ASCII characters, and saving it.  In that
> > case, we use selecte-safe-coding-system to decide the coding
> > system to encode the buffer contents.

> I think that's a different situation: base64-decode-region inserts raw
> bytes, not non-ASCII characters.  So select-safe-coding-system may not
> work correctly, because (AFAIK) it was not designed for that case.

Have you tried it?  select-safe-coding-system should suggest
raw-text if the buffer contains raw bytes.

---
Kenichi Handa
handa@m17n.org