bug#34569: 26.1.90; Zero wide scroll bars

[Eli Zaretskii]

> Date: Sun, 24 Feb 2019 09:43:37 +0100
> From: martin rudalics <rudalics@gmx.at>
> CC: 34569@debbugs.gnu.org
> 
>  >> But yes: One way to fix the aborts should be to disallow setting the
>  >> 'scroll-bar-width' frame parameter to zero.
>  >
>  > Then I think we should do that.
> 
> It means though that we have to do some non-standard surgery in the
> frame parameters area.

That's okay, we already do similar things with some parameters.