bug#61337: 29.0.60; Setting frame-title-format makes Emacs to steal focus

[Eli Zaretskii <eliz@gnu.org>]

> From: Po Lu <luangruo@yahoo.com>
> Cc: ofv@wanadoo.es,  61337@debbugs.gnu.org
> Date: Thu, 09 Feb 2023 18:23:00 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Which part? the change in xfns.c is fine (it just makes the code
> > slower, so perhaps test EQ first and Fstring_equal if EQ doesn't
> > return non-zero)
> 
> Just the change in xfns.c.  It fixes a bug in the original code (which
> was trying to test whether or not both strings were equal, but didn't
> handle the case where the strings were equal, but not EQ.)

This part of the change is OK for emacs-29.

> > However, to tell the truth, I don't really understand the phenomenon
> > being complained about in this case.  The original report says: "the
> > z-order is not altered", whereas the conclusion of the analysis is
> > "KWin seems to treat this as Emacs asking to be focused".  Would you
> > please describe the problem in easier-to-understand terms and use the
> > user-facing behavior instead of technical terms like z-order, so that
> > I could at least make up my mind whether this issue is serious, and
> > perhaps think about alternative solutions?  E.g., I don't yet
> > understand why returning early in x_set_title should help here, and
> > how.
> 
> The problem is that KWin apparently focuses a window if its title
> changes while it is in a different workspace.  That's misbehavior on
> KWin's part, and likely a bug.

How is this related to "the z-order isn't change" problem which Óscar
complained about?