bug#32950: 27.0.50; Strange display bug in *Help* buffer

[Stefan Kangas]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Stefan Kangas <stefan@marxist.se> writes:
>
>>> What does (window-width) evaluate to for you here?  (It's 80 for me.)
>>
>> 255 before running `C-h b', 128 after.
>
> Oh, you resized the terminal?  Well, then that's expected.

No, I didn't resize it.  (I wrote up a detailed explanation, but the bug
was fixed by your below commit, so it's not relevant now I think.)

> Hm...  hang on a minute.  Can't we just use an underline on TUI?  Or was
> that what Customize did?  Hm...  OK, tried it now, and it seems to work
> without the odd point motion?  So I've now pushed it to Emacs 29.

With that change, the above bug is gone.  And it looks much better!
I think we should change customize to use that, too.

However, especially on a graphical display, it would be nice if you
couldn't place point on the actual divider.  It looks almost as jarring
as the weird point movement to me.