On Tue, Apr 30, 2024 at 01:25:32PM +0200, Patrick Steinhardt wrote:

quoted

So this is where I will show my ignorance of reftables. I assume it
still has to implement FETCH_HEAD as a file (since it holds extra data).
But does it do the same for other names outside of "refs/"? I am
assuming not in the paragraph below.

No, that's why we originally introduced the "special refs" syntax, as
defined in gitglossary(7). There are only two files that behave like
refs, but circumvent the ref backend: FETCH_HEAD and MERGE_HEAD. Both of
these have special syntax and carry additional metadata, and as such
they cannot be stored generically in a ref backend.

All other root refs are stored via the ref backend.

OK, that matches what I guessed based on the existence of special refs. ;)
Thanks for confirming.

Part of me does wonder if things would be simpler if ref backends only
handled refs/*, and pseudo/special/root refs remained as their own thing
in the filesystem. They're a limited set, so we don't really care about
scaling in the same way. And their point is to be somewhat ephemeral, so
even if you wanted to be clever with a replicated database-backed refs
store, you probably don't care if CHERRY_PICK_HEAD goes away.

And it's not clear to me what the path forward is for scripts which poke
at .git/* to determine repo state. For example, I think git-prompt.sh
looks at CHERRY_PICK_HEAD and REVERT_HEAD to decide what we're doing.
Maybe we just roll all of that into a command which returns all details
of the repo state?

quoted

So I think dropping REFFILES it would still pass, but we are not really
testing anything that interesting for reftables. That said, I would be
OK dropping the REFFILES in the name of simplicity and just documenting
it in the commit message.

Yeah, I'd prefer to drop it. We should only specify the REFFILES prereq
as sparingly as possible to ensure that behaviour is as consistent as
possible across the implementations.

Makes sense. I'll change that for my next re-roll (which probably won't
be until next week, as I'll be offline for a bit).

-Peff