bug#13540: 24.3.50; Regression in trunk: auto-revert-mode fails on files accessed via samba

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 25 Jan 2013 08:46:59 +0100
> From: Dani Moncayo <dmoncayo@gmail.com>
> Cc: michael.albinus@gmx.de, 13540@debbugs.gnu.org
> 
> > Each time you evaluate the expression that calls w32notify-add-watch,
> > you should see another "New Thread" announcement.
> 
> Yes I do.
> 
> > This is normal,
> > since each watch you add starts a new thread where the watching code
> > runs.
> 
> Ok.
> 
> > Can you use Process Explorer or "pslist -d emacs" (both tools are from
> > the Sysinternals package) to see if the threads started when you
> > invoke w32notify-add-watch keep running, or die/exit?
> 
> I observe (with process explorer) that the new threads keep running.
> 
> > The lack of any messages suggests that the threads continue to run,
> > but file notifications never come in, which probably means we cannot
> > detect this problem automatically, and must rely on the users who know
> > which volumes can and cannot be supported.
> 
> Ok, if Emacs cannot determine itself whether file notifications work,
> I'll set `auto-revert-use-notify' to nil on that machine.
> 
> > Also, I presume that you tried to modify files on the mounted volumes,
> > while you had GDB attached to Emacs.
> 
> Of course.  I started and "emacs -Q" process under GDB, and from that
> emacs session I visited the file on the mounted volume and turned on
> auto-revert-mode.  Then, if I modify the file with another program,
> the emacs buffer isn't reverted and the GDB console doesn't show any
> message.

Thanks.

I guess autorevert should allow users to specify whether notifications
should be used on a per filesystem basis, rather than just globally
for the entire session.