bug#28023: fix make-temp-file race on local host

[Eli Zaretskii]

> Cc: michael.albinus@gmx.de, 28023@debbugs.gnu.org
> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Sat, 12 Aug 2017 10:57:26 -0700
> 
> I see lots of exceptions to these conventions, presumably either because 
> developers don't know the intent or because the code was written before the 
> conventions were established. Still, it's better to document the intent so I 
> installed the attached patch to do that.

Thanks, I agree this should be documented.

> I'll adjust the make-temp-file patch accordingly.

Thanks.