bug#27210: 25.2; Recovering loaddefs.el with desktop-mode hangs when linum is on

[Eli Zaretskii <eliz@gnu.org>]

> From: npostavs@users.sourceforge.net
> Cc: 27210@debbugs.gnu.org,  ambrevar@gmail.com
> Date: Sun, 04 Jun 2017 11:08:59 -0400
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > And don't forget that the initial frame is invisible in non-daemon
> > sessions as well, until some point during startup.
> 
> I don't understand, is this an objection?

Sorry for being unclear: I meant to point out that a non-daemon
startup initially has such a frame as well, and we never heard any
complaints about that.  Which might mean that some of the code
routinely run during startup expects to find that frame marked
visible.

> > My alternative proposal is much simpler, is localized to linum.el, and
> > in a nutshell tests exactly the same condition, since any frame in a
> > daemon session that can be visible is by definition a client frame.
> > Do you see any disadvantages with installing that instead?
> 
> The only disadvantage is that we still have this invisible daemon frame
> which is marked as visible.  I agree it's okay to apply your patch now
> and see if we get some other similar problems later.

OK, I've pushed the change.  Let's keep an eye on similar problems if
they pop up.