From: Jeff King <peff@peff.net>
Date: Tue, 12 Jul 2016 15:51:41 GMT
Subject: Re: gc and repack ignore .git/*HEAD when checking reachability
Message-ID: <20160712155141.GA5967@sigill.intra.peff.net>
In-Reply-To: <CACsJy8C+NEP1HJq8w1frOy=UOv5-SA+b7MkbX8DE_vU-zjX0XQ@mail.gmail.com>

On Tue, Jul 12, 2016 at 05:46:12PM +0200, Duy Nguyen wrote:

> I'm not opposed to letting one worktree see everything, but this move
> makes it harder to write new scripts (or new builtin commands, even)
> that works with both single and multiple worktrees because you refer
> to one ref (in current worktree perspective) differently. If we kill
> of the main worktree (i.e. git init always creates a linked worktree)
> then it's less of a problem, but still a nuisance to write
> refs/worktree/$CURRENT/<something> everywhere.

True. I gave a suggestion for the reading side, but the writing side
would still remain tedious.

I wonder if, in a worktree, we could simply convert requests to read or
write names that do not begin with "refs/" as "refs/worktree/$CURRENT/"?
That makes it a read/write-time alias conversion, but the actual storage
is just vanilla (so the ref storage doesn't need to care, and
reachability just works).

The trickiest thing, I think, is FETCH_HEAD, which is not really a
ref (because it may have a bunch of values, and contain extra
information).

-Peff