bug#28180: [w32] Unicode characters in subprocess (git) arguments changed to space

[Eli Zaretskii <eliz@gnu.org>]

> From: Noam Postavsky <npostavs@users.sourceforge.net>
> Date: Mon, 28 Aug 2017 10:42:14 -0400
> Cc: 28180@debbugs.gnu.org
> 
> Just to understand the issue better, I applied the attached diff to
> use CreateProcessW.

I hope you realize that this is just a quick hack, which cannot work
in general, yes?  For starters, the command line is not a file name,
in general, so using filename_to_utf16 is inappropriate.  Also, I
think the environment variables need to be converted to UTF-16.

> It seemed to work, but only when I start emacs from mingw's msys
> shell. When running from cmd.exe it still translates to space.

What exactly did you run from cmd.exe?  What command?

> Furthermore, when I run an unpatched Emacs from the msys shell, the
> output of the test I posted above is different:
> 
> (call-process "git" nil '(t t) nil
>               "-c" "alias.x=!x() { printf '%s' \"$1\" | od -tx1; }; x"
> "x" "(好)")
> 0000000 28 c3 a5 c2 a5 c2 bd 29
> 0000010
> 
> Do you have any idea what setting could cause this?

Windows tries to interpret UTF-8 as something else?