GNU bug report logs - #14604
24.3.50.1; Possibly incorrect behaviour of frame-selected-window

Previous Next

Full log

View this message in rfc822 format

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: E Sabof <esabof <at> gmail.com>
Cc: 14604 <at> debbugs.gnu.org
Subject: bug#14604: 24.3.50.1; Possibly incorrect behaviour of frame-selected-window
Date: Thu, 13 Jun 2013 10:35:18 -0400

> This works on 24.3, but on trunk all windows will be shown as "selected".
> (setq-default
>  mode-line-format
>  '(:eval (if (eq (frame-selected-window)
>                  (selected-window))
>              "selected"
>              "not-selected")))

Indeed this doesn't work any more.  This was one of the very few places
where (eq (frame-selected-window) (selected-window)) was nil, and this
"invariant" is presumed at various places in the C code, so it was
a bug.

BTW, this worked in Emacs<24.3 if you wanted to highlight every frame's
selected-window, but not if you wanted to highlight "the one and only
selected-window".  For single-frame settings, there's no difference,
of course.

There is no alternative, yet.  We should probably provide some ad-hoc
primitives (call them maybe display-selected-window and
display-frame-selected-window) which return something like "the window
that was selected when we entered redisplay".


        Stefan

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.