bug#24953: 25.1; Possible inefficiency in UTF-8

[Eli Zaretskii <eliz@gnu.org>]

> From: Eli Barzilay <eli@barzilay.org>
> Date: Mon, 21 Nov 2016 16:38:07 -0500
> Cc: 24953@debbugs.gnu.org
> 
> > It isn't expected with Emacs 25.1, as it specifically sets up things
> > assuming Git reports its data in UTF-8.  Are you sure you didn't set
> > i18n.commitEncoding in your Git configuration, or have some non-ASCII
> > text encoded in something other than UTF-8 in that repository?
> 
> I just ran into an encoding problem, with files now: openning a utf-8
> file with a single lambda (\316\273) sometimes failes, and I traced this
> to whether I start Emacs from Windows or from a cygwin shell.

That's unrelated to Git, though.

> In the latter case, my shell has an explicit LANG setting and the
> result is that Emacs opens that file fine, but in the first case,
> when Emacs is started directly by windows, there is no LANG, and the
> utf-8 file is not treated as such (looks like it opens it in
> latin-1).  I verified this with "emacs -Q" too.

Emacs sets LANG internally, by using a suitable Windows API, when it
runs on Windows (unless LANG is set in the shell), so the fact that
LANG is not set is not a problem in itself.

What you describe is expected with the default Windows settings: a
file that is in no particular mode which requires UTF-8 will not be
automatically decoded as UTF-8, without some customizations.  You
could also put file-local variables into the file.