bug#38255: 27.0.50; Indentation error-out in css-mode

[Lars Ingebrigtsen <larsi@gnus.org>]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Open a.css and type:
>
> foo {
> }
> }
>
> The following backtrace is triggered.
>
> Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p nil)
>   smie-next-sexp(#f(compiled-function () #<bytecode 0x155d7de91a0d>) #f(compiled-function (n) #<bytecode 0x155d7f00a465>) #<subr car> #f(compiled-function (x) "Return the car of the cdr of X." #<bytecode 0x1ffc61806017>) "}")
>   smie-backward-sexp("}")
>   smie-indent-keyword()
>   run-hook-with-args-until-success(smie-indent-keyword)

Stefan, I tried to follow the logic in smie-backward-sexp here, but I'm
somewhat confused.  (More than usual, even.)  Could you have a look at this?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no