On Sat, 6 Feb 2021 at 11:04, Lars Ingebrigtsen <larsi@gnus.org> wrote:

> Reuben Thomas <rrt@sc3d.org> writes:
>
> > javascript-mode is an alias for js-mode, and some third-party modes (e.g.
> > json-mode) derive from it.
> >
> > (provided-mode-derived-p 'js-mode 'prog-mode) == t
> >
> > but
> >
> > (provided-mode-derived-p 'javascript-mode 'prog-mode) == nil
> >
> > Hence in json-mode, (derived-mode-p 'prog-mode) evaluates to nil, which
> seems
> > unfortunate.
>
> Yup.  I've now changed the function to also work on MODE parameters that
> are function aliases.
>

Many thanks!

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