bug#64822: Broken tab-bar rendering when increasing internal-border-width

[Eli Zaretskii]

> From: GB <g.bickovich@gmail.com>
> Date: Sun, 23 Jul 2023 22:48:19 +0300
> 
> - emacs -Q
> - Evaluate this expression:
>   (add-to-list 'default-frame-alist '(internal-border-width . 10))
> - Create a new frame (C-x 5 2)
> - Create a new tab (C-x t 2)
> - Wait a second or start typing
> 
> Results:
> The tab bar gets cut in half by the area where text is.
> Switching tabs flashes the tab bar the way it's supposed to look like for a 
> split second.

I cannot reproduce this (but mine is not a GTK build).  Can you show a
screenshot of "The tab bar gets cut in half by the area where text
is"?  I'm not sure I have a clear idea what this is supposed to look
like.