bug#34343: [PATCH] Make project--find-regexp-in-files work with remote files

[Felicián Németh]

Hi Dmitry,

I forgot that project-files are new in emacs-27, so there's no need to
worry about backward compatibility.  Also, there is no need to hurry
either, because emacs-27 won't be released soon.  Nevertheless, I would
love to have a convenience function returning "complete" file names,
even if the function's name is not project-files.

> So we can mandate that project-files returns local names. And add a
> new method that returns remote-id corresponding to the project.
>
> This will codify that the whole project must have one remote-id.

> So I wonder if somebody has an opinion on that. Maybe we'll want to
> include remote files as "external roots" in some projects? Or files
> inside archives?

I never worked on a project with multiple remote-ids.  However, if we
can come up with something simple that does not have significant
performance impact on the local case, we should solve the general case,
I think.  Remote operations tend to be slow, so I think project.el can
run more complex algorithms in that case.