Re: [Emacs-diffs] trunk r114533: Revert 114527

[Dmitry Gutov]

On 05.10.2013 22:02, Eli Zaretskii wrote:
> > Because its value doesn't change (from the initial `undecided-unix')
> > even after the buffer is saved with new, non-ASCII characters.
>
> Didn't Emacs asked you to select an encoding when you saved?

Nope, it saves the file correctly automatically.

> Also, what were the non-ASCII characters,

Some cyrillic characters, for example: фывапролд

> and what is your
> default-buffer-file-coding-system?

utf-8-unix

> > So far I've decided to use `select-safe-coding-system-function', but it
> > just adds to the mess:
>
> Please describe the issue from the beginning, I cannot find it in the
> mailing list archives.  It's hard to judge the solution without
> knowing the details of the problem.

Sorry, at first I thought I had the solution (with 
last-coding-system-used), so I didn't start the discussion.

Scenario:

1. Open an .rb file, written in ASCII (buffer-file-coding-system will be 
undecided-unix).
2. Switch to the Russian layout (usually that happens by accident, but 
sometimes even on purpose, according to my colleagues), type some text 
in Russian, press `C-x C-s'.
3. The file is saved fine, but buffer-file-coding-system is still 
undecided-unix. And `ruby-mode-set-encoding', from before-save-hook, has 
inserted `# coding: undecided' at the beginning of the file.

If I kill the buffer, then open the file again, 
buffer-file-coding-system is now utf-8-unix. If I make a modification 
and save the buffer now, the first line is changed to the correct `# -*- 
coding: utf-8 -*-'.