bug#53012: 28.0.90; completion--nth-completion: Throw a meaningful error

[Stefan Monnier]

Daniel Mendler [2022-01-04 21:12:47] wrote:
> In the context of the GNU ELPA Vertico/Mct/Orderless/Embark ecosystem we
> teach users to adjust the completion style. Unfortunately
> completion--nth-completion is not very robust against misconfiguration.
> I propose to throw a more meaningful error instead of the nil error.

Thanks, looks good.
Pushed to `master`.


        Stefan