bug#50572: 28.0.50; [PATCH] fix VC to find the responsible backend with the most specific path.

[Eli Zaretskii]

> Cc: 50572@debbugs.gnu.org
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Wed, 15 Sep 2021 13:35:14 +0300
> 
> On 14.09.2021 19:03, Eli Zaretskii wrote:
> > So maybe this never worked for registering, in which case I think it
> > would be good to add that.  Because the manual says this should work
> > for "C-x v v" in general, not just under some conditions.  And what's
> > the most natural occasion to determine the backend if not when you
> > register a file?
> 
> I don't know what the manual says, but vc-next-section's signature calls 
> the prefix argument's value VERBOSE, and vc-register doesn't have a way 
> to trigger backend-prompting either. So it might be difficult to add 
> that feature in a backward-compatible manner.

We could use a different arg value, for example "C-u" will do one
thing and "C-u C-u" another.  There's precedence for that.