On Wed, Dec 12, 2018 at 3:15 PM Óscar Fuentes <ofv@wanadoo.es> wrote:

>
>
> You are asking for being bug-compatible with previous Emacs because you
> must cope with bugs on other applications :-)


Yes, if you will.  That is what the world is like.



> Do you think that this
> problem is frequent enough?


Every time I start Emacs, or everytime someone in my $DAYJOB starts Emacs
after upgrading to Emacs 27.  Frequent enough?



> What applications are those that don't admit
> an slash after the volume letter in HOME?
>

30-year+ old, big bad misbehaving Lisp-based applications.  Kinda like
Emacs, I suppose :-)

João