bug#46827: Broken initial size of GTK3 frame

[martin rudalics]

>> It's due to to the fact that WM notifications about new frame sizes may
>> be processed earlier or later.  I tried to fix that behavior in commit
>> a190b4cfd8b6f42a91678ac7292e1cceccd168e7 by having adjust_frame_size
>> pick up such notifications on the fly and am closing this bug.
>
> Unfortunately, this commit caused a regression: now there is distracting
> blinking of the frame that looks like the visual effect of visible-bell
> when it flashes the frame to represent a bell.
>
> This problem can be reproduced only in Gnus.  With such configuration:
>
>    (push '("\\`\\*Summary .*\\*\\'" .
>            (display-buffer-in-tab
>             (tab-name . "*Summary*")))
>          display-buffer-alist)
>
> opening a Gnus group in a new tab flashes the whole frame where empty space
> instead of the frame content is visible for a short time.
>
> This problem can't be reproduced with just creating a new tab,
> it only manifests in Gnus, maybe something in gnus-summary-read-group-1
> with gnus-configure-windows forces frame redisplay or something like this.
>
> This problem doesn't exist without recent changes in a190b4cfd8.

Please try to provide some sort of recipe to reproduce this.  Ideally
without Gnus because I never used it.  Also, I've never seen a frame
"flash".  Is that a new frame?  Is there anything broken in the frame
after the flash?

martin