Re: Tab bar tabs landed on master

[Juri Linkov]

>> Enabling tab-bar-mode grows the frame's height (not always, just the
>> first time).  Disabling the mode does not shrink it. Is that intended?
>
> What's worse, this also happens in the -nw session on MS-Windows, and
> that makes the session all but unusable, because the echo-area is
> mostly invisible, and the mouse clicks don't work, probably because of
> the same miscalculation of coordinates.

Tab-bar code is just a copy of tool-bar code.  And indeed
running `emacs -Q -f tool-bar-mode' that disables tool-bar-mode
exposes the same problem:

(let ((initial (assq 'outer-size (frame-geometry))))
  (tool-bar-mode 1)
  (tool-bar-mode 0)
  (list (assq 'outer-size (frame-geometry)) initial))

=> ((outer-size 680 . 693) (outer-size 680 . 676))

The reason why this problem was unknown until now
is because tool-bar-mode is enabled by default.
But disabling it with a command line option
of by using .Xresources causes frame resizing.

So we need to fix it simultaneously for both tool-bar and
tab-bar.  I'd appreciate any help from our experts in
window-related code.