GNU bug report logs - #78835
Wrong pop-to-buffer behavior after one display-buffer-in-side-window call

Previous Next

Full log

View this message in rfc822 format

From: martin rudalics <rudalics <at> gmx.at>
To: Dmitry Gutov <dmitry <at> gutov.dev>, 78835 <at> debbugs.gnu.org
Subject: bug#78835: Wrong pop-to-buffer behavior after one display-buffer-in-side-window call
Date: Tue, 15 Jul 2025 10:06:14 +0200

>> You typed C-x v = in a configuration with two side-by-side windows,
>> right?
>
> Yes. Ones with seemingly equal width.
>
>>  > And then pressing 'q' in it restored that width.
>>
>> If the width changed after displaying the buffer, this is the expected
>> behavior.
>
> After displaying and/or after quitting it.

After quitting it.

>> Here I can trigger it as follows with emacs -Q: Show window.el in a left
>> window and a *Help* buffer in the right window.  The ‘quit-restore’
>> parameter of the *Help* window is
>>
>> (window window #<window 3 on window.el> #<buffer *Help*>)
>
> Not exactly the same value that I see, but I guess that depends on how
>  the Help buffer was created anyway.

Right.

>> Now I do C-x v = in the left window which displays the diff buffer in
>> the right window but does _not_ change its width.  Next I change the
>> width of the right window by dragging the mode line divider with the
>> mouse, type 'q' in the right window and am asked
>>
>> (window window #<window 3 on window.el> *Help*) ... (*Help* 1 #<marker at 1160 in *Help*> 93) (y or n) y
>>
>> where the 93 is the previous width which gets restored if I type 'y'.
>> What do you get?
>
> I get the same (if the windows windows are equal in the
> beginning). And it's somewhat surprising but also logical at the same
> time.

'quit-window' is primarily thought to work for short-lived windows where
the configuration before displaying the buffer is still visually present
in the user's mind.  Like restoring a window configuration, but without
deleting newer windows or recreating older ones.

> OT2H, I also see 'vc-diff' resizing the width (evening the windows) if
> its target window takes up less than half of the frame.

I suppose that you want to customize 'even-window-sizes' here.

> Is that a new behavior? I don't think I've noticed it before. Not sure
> I like it in principle either (my widths are usually either even, or
> more rarely uneven with a specific purpose). It also only happens if
> the window spans the whole height, but not inside a vertical split.

Evening widths was added for Emacs 25 - ten years minus one week ago.

martin

Previous Next

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