Thanks alot for your comments!

"Dmitry Gutov" <dgutov@yandex.ru> writes:

[...]
> The REQUIRE-MATCH argument should be t, I think.
Done.

>  > +      (lambda (buffer)
>  > +        (when-let* ((path (buffer-file-name (cdr buffer)))

[...]

> Call it file or file-name.
Done.


>  > +                    (true (file-truename path)))
>
> Do we need this conversion? It'll add some runtime overhead, and I'm not
> sure in which conditions the result will be different.
I removed it, seems to work fine :).


>  > +          (when (file-in-directory-p true (project-root pr))
>  > +            'buffer)))))))
>
> Why 'buffer and not t?
I just figured it as readable, but t is there now!

Theo