bug#52986: 29.0.50; tab bar doesn't immediately show

[Eli Zaretskii]

> From: Dustin Lacewell <dlacewell@gmail.com>
> Date: Mon, 3 Jan 2022 13:15:02 -0600
> 
> Evaluating (tab-bar-mode 1) after startup, the tab-bar does not immediately 
> appear. I must resize or bring
> some other (non-emacs) window in front of emacs in order for it to (repaint? 
> and) display.

Not reproducible here.

> I use a tiling window manager on Linux, not sure if that's relevant.

It probably is.  Activating tab-bar-mode involves resizing the frame,
so the WM is involved.  If it doesn't feed us the events we expect, we
won't repaint the frame, I think.