Re: Performance issue in project.el

[Ergus]

Reading the issue I see that there is already vc-file-prop-obarray.

Could vc-responsible-backend use that?

On Tue, Jun 29, 2021 at 12:14:57AM +1200, Phil Sainty wrote:
> On 2021-06-28 23:42, Ergus wrote:
> > After reading the function vc-responsible-backend I can see that it 
> > uses
> > a mapcar to test the responsible; so all of them are always tested in
> > every single call every time.
>
> It didn't in Emacs 27, but see bug #42966 and commit 2697123933e3
>
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=42966
>
> commit 2697123933e3ac7ed4e21a6d12746a98ed7fa74a
> Author: Lars Ingebrigtsen <larsi@gnus.org>
> Date:   Mon Oct 26 21:10:36 2020 +0100
>
>    Make vc-responsible-backend choose the most specific backend
>
>    * lisp/vc/vc.el (vc-responsible-backend): Search through all the
>    VC backends instead of the first one, and choose the one that's
>    most specific (bug#42966).