Re: Strange behaviour on Windows 10

[Eli Zaretskii <eliz@gnu.org>]

> From: Pascal Quesseveur <pquessev@gmail.com>
> Date: Fri, 27 Sep 2019 14:48:41 +0200
> 
> #+BEGIN_EXAMPLE
> >type xtest.cmd
> @echo off
> if exist "C:\Windows\System32" (echo OK) else (echo NOK)
> if exist "C:\Windows\System32\OpenSSH" (echo OK) else (echo NOK)
> 
> >xtest
> OK
> OK
> #+END_EXAMPLE
> 
> and in emacs -Q (version 26.1):
> 
> #+BEGIN_EXAMPLE
> (defun xtest()
>   (interactive)
>   (call-process "xtest" nil t nil))
> M-x xtest
> OK
> NOK
> #+END_EXAMPLE

One possible reason is that your Emacs is a 32-bit build.  Windows
silently redirects all accesses to C:\Windows\System32 from 32-bit
programs to C:\Windows\SysWOW64.  If there's no OpenSSH there, you get
an error.

> #+BEGIN_EXAMPLE
> > which --version
> GNU which v2.20, Copyright (C) 1999 - 2008 Carlo Wood.
> (Modified for MS-Windows/MinGW by Eli Zaretskii.)
> > which ssh.exe
> which: no ssh.exe in (.;C:\Program...;C:\WINDOWS\System32\OpenSSH\;...)
> #+END_EXAMPLE

This which.exe is a 32-bit program, so it gets the same treatment from
Windows.