Re: saveplace: don't ask for coding system

[Eli Zaretskii <eliz@gnu.org>]

> Cc: dreitter@inf.ed.ac.uk,  lekktu@gmail.com,  emacs-devel@gnu.org
> From: Karl Fogel <kfogel@red-bean.com>
> Date: Mon, 03 Dec 2007 02:59:33 -0800
> 
> It would be more helpful if, instead of saying what encoding *not* to
> use, you (or someone) would say what encoding *to* use

I thought that was obvious: emacs-mule.

> and why :-).

I thought that was obvious: because it supports all the characters
Emacs can handle.

> In the thread, you objected to utf-8 because Emacs-mule supports some
> characters that utf-8 doesn't (I hadn't known that, but I'll take your
> word for it).

In Emacs 22, only mule-unicode-* characters can be encoded with
UTF-8.  We do a lot of juggling behind the scenes to pretend that
characters from other charsets are somehow equivalent to (or mapped
into) Unicode codepoints, but that's camouflage.  Cyrillic ISO-8859-5
characters and Cyrillic mule-unicode-* characters are still different
characters, for example.

> However, Juanma pointed out that utf-8 was used for the
> ido-history file, and that the reason this was okay was that the data
> is just filenames (as with saveplace); he pointed to a thread on this.

That discussion was about Emacs 23, which will be Unicode based and
where UTF-8 will be able to support all characters (or so I think).
EMACS_22_BASE is a stable branch, so we are not supposed to install
there changes that _might_ work, only changes we know _for_sure_ they
_will_ work.