bug#61496: 30.0.50; Default value of icon-title-format

[Eli Zaretskii <eliz@gnu.org>]

> From: Óscar Fuentes <ofv@wanadoo.es>
> Cc: Po Lu <luangruo@yahoo.com>,  61496@debbugs.gnu.org
> Date: Tue, 14 Feb 2023 15:57:21 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> BTW, for the record:
> >> 
> >> icon-title-format stopped working after some Emacs 24.x release, and was
> >> only fixed in Emacs 29.
> >> 
> >> I don't know if that's relevant or not.  I have no opinion as to the
> >> arguments you or Oscar have presented, as I have not yet read them, but
> >> I am in favor of his change.
> >
> > I'm not opposed to the change, I just asked for minor changes in some
> > details of the change.
> 
> The core of my proposal, is changing icon-title-format's default, so
> users (and external scripts!) will keep observing the same behavior
> after upgrading to 29.

I can't believe that we are actually making such a fuss about asking
the affected users to add a single line to their init files:

  (setq icon-title-format t)

At times, bugfixes end up producing backward-incompatible behavior,
and when that happens, we call those cases out in NEWS and tell users
how to unbreak whatever could be broken by the changes.  Why cannot
that be done in this case?

Please understand: the change you propose, at the 95th minute, _is_
backward-incompatible.  You argue that no one could possibly not want
such a change, but I have too much gray hair from watching such
assumptions and firm opinions defeated by the bitter reality to
believe this.  The only relatively reliable judge is user feedback,
and we don't have time to wait for that for Emacs 29.  So I cannot
agree to what you propose, and urge you to see the dangers.

But if you think the change in Emacs 29 behavior in this aspect is so
grave, we could instead revert that change on emacs-29, leaving
icon-title-format broken as it was since Emacs 24, and leave the fix
only on master.  Then on master we could perhaps change the default
more easily.

> OTOH, I think that what Po just said speak volumes about the abundance
> and importance of icon-title-format on user's config.

Granted, I took his opinion into account.