bug#50798: 28.0.50; Tab line close button is off-center until it is highlighted with the mouse

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Sat, 25 Sep 2021 09:17:03 +0200
> Cc: Po Lu <luangruo@yahoo.com>
> 
> Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text
> editors" <bug-gnu-emacs@gnu.org> writes:
> 
> > The close button for each tab in a tab line is off-center unless it's
> > under mouse face.
> >
> > Enable tab-line-mode, and compare the position of the close button (X)
> > in any tab when it is under mouse face to when it is not.  The
> > difference is quite obvious.
> 
> I'm unable to reproduce the problem

You need to have at least two tab-line buttons to see that, because it
only shows on the non-current tab.