bug#28591: 27.0.50; xterm-set-window-title

[Mark Oteiza <mvoteiza@udel.edu>]

On 05/10/17 at 01:16pm, Eli Zaretskii wrote:
> > Date: Sat, 30 Sep 2017 15:26:27 -0400
> > From: Mark Oteiza <mvoteiza@udel.edu>
> > Cc: yamaoka@jpl.org, 28591@debbugs.gnu.org
> > 
> > > So you are saying the title is only restored when Emacs exits?
> > > Otherwise, I think I'm missing something: in what case(s) your
> > > restoration code does work?
> > 
> > There is no restoration code at the moment--I totally overlooked it
> > because of my shell configuration.
> > 
> > The following works for me on a VTE based terminal.
> > The commented bits I would expect to do _something_ on XTerm, but
> > I have been unable to get titles to restore on XTerm, whether or not
> > I set the allowWindowOps and disallowedWindowOps resources.
> 
> OK, how about pushing this to master, with some defcustom, by default
> off, to control whether this feature is used?  With any luck, we might
> have contributions for others to increase the number of configurations
> supported by this feature.

After running with the patch for a bit, I notice sometimes there is
a long (second or two) delay when opening a new frame--I guess because
of a possible delay like is mentioned in delete-frame-functions.
I would prefer to simply turn the existing code off by default than
introduce possibly more broken behavior, especially when it only
supports a subset of xterm-like terminals.