bug#41821: 28.0.50; read-directory-name in vc commands should provide defaults from projects

[Juri Linkov <juri@linkov.net>]

>>> +;; Or use project-try-vc after all. But this should be faster in the
>>> +;; event when there actually are non-VC based projects in the list.
>>> +(defun vc--known-vc-roots ()
>>> +  (require 'project)
>>> +  (defvar project--list)
>>> +  (project--ensure-read-project-list)
>>
>> Calling internal project.el functions from vc.el?  Really?
>
> The alternative would be to create a function like that in project.el.
>
> But I hesitate to make it public, sorry.

Why not?

We have to decide which of them should be dependent.  It would be fine
either way: project.el to use vc.el public functions, or vice versa.

>>> Personally, though, when I want behavior like this, I would probably just
>>> type 'C-x p v'.
>> 'C-x p v' is not a replacement for 'C-x v L'.
>
> 'C-x p v L', then?

'C-x v L' needs to provide a list of recently used repositories.
Actually, this feature doesn't depend on project.el, so recently
used repositories could be recorded independently without project.el.
But it would be nice to share these directories between project.el and vc.el.