Re: saveplace: don't ask for coding system

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 4 Dec 2007 17:40:57 +0100
> From: "Juanma Barranquero" <lekktu@gmail.com>
> Cc: "Emacs Devel" <emacs-devel@gnu.org>
> 
> Which brings forth a similar case: the savehist-file (from
> savehist.el) is by default saved in utf-8 (at least on recent XEmacs
> and Emacs). However, the eol-conversion is left for Emacs to decide.

When saving history, there's nothing to decide: savehist uses a
temporary buffer, which is born with the native EOL convention of the
underlying platform: -unix on Posix platforms, -dos on Windows.

> That's Not Good when some of the saved variables contain "^M" or "^J"
> on a non-unix environment.

So you mean when reading the history file, yes?

> For example, I did some "^M^J" -> "^J"
> replacements (to fix a garbled patch) on Windows, and in subsequent
> invocations of Emacs the contents of query-replace-history got sillier
> and sillier: "^M^M^J", "^M^M^M^M^J", etc.
> 
> Now, savehist.el is friendly enough to contain a variable
> `savehist-coding-system', so it's easy to fix in your own .emacs. The
> question is, for a file whose intention is to preserve exactly some
> variable's contents, wouldn't be a better default to use utf-8-unix?

I don't think it's better, because a lone ^M can fool Emacs even if we
use -unix.  What would help, I think, is have an explicit EOL
conversion stated in the coding: cookie.  Then the fragile guesswork
will be bypassed.