Subject: Re: bug#63469: 29.0.90; project.el doesn't add menu-bar entries

From: Dmitry Gutov <[email-masked]>
Date: Mon, 22 May 2023 22:54:52 +0300

On 22/05/2023 22:49, Spencer Baugh wrote:
> And actually, the mention of VC makes
> me realize: We already do something expensive by default for every new
> buffer: Query the VC state.  So maybe it's not so bad to run
> project-current every time we make a new buffer?  Or at least, in the
> exact same situations that we query the VC state?  Maybe we can even
> implement some sharing between the project-current lookup and the VC
> state query, for the vc project backend?

The VC project backend is not the only backend out there. Others' 
performance characteristics may well be different.

Further, its root-finding logic is different from VC. We also cannot 
simply see which backend the current file is registered at because 
project-vc has different options which affect how the root is determined.

Long story short, we won't be able to simply reuse VC's cached info.

 > (I personally agree that this should be always on, with perhaps a user
option to turn it off.)

I'm fairly sure not everybody will like the additional delay when 
visiting files over Tramp.