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

[Dmitry Gutov <dgutov@yandex.ru>]

On 05.10.2013 22:38, Eli Zaretskii wrote:
>> Date: Sat, 05 Oct 2013 22:16:36 +0300
>> From: Dmitry Gutov <dgutov@yandex.ru>
>> CC: monnier@iro.umontreal.ca, emacs-devel@gnu.org
>>
>> 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 -*-'.
>
> "Changed"?  You mean, there was an existing coding: cookie in the file
> before you typed the cyrillic characters?  If so, what did that
> original coding cookie say?

No, that's a continuation of the scenario. That's what happens if I kill 
the modified buffer with the newly-added `# coding: undecided`, and then 
reopen it.

The presence of the `# coding' line is not particularly important. The 
fact that the file has some cyrillic characters in it, however, makes 
the buffer open with buffer-file-coding-system `utf-8-unix'.

> Also, do you see the same behavior with Emacs 24.3?

Yes and no. The `ruby-mode-set-encoding' bug is there, because it uses 
`before-save-hook', but `buffer-file-coding-system' does change after 
the buffer is saved, in accordance with your preference below.

So I don't need to kill and reopen the buffer. Just making another 
change and saving sets `coding:` comment to the right value (as long as 
the second change leaves at least some non-ASCII characters in the buffer).

> I think it is OK to silently save the buffer with UTF-8, if that's
> your default, but the value of buffer-file-coding-system should in
> that case change to UTF-8.

Should I file a bug, or..?