Re: [PATCH 1/1] worktree refs: fix case sensitivity for 'head'

On Fri, Dec 14, 2018 at 6:38 PM Duy Nguyen [off-list ref] wrote:

On Fri, Dec 14, 2018 at 6:22 PM Jacob Keller [off-list ref] wrote:

quoted

On Thu, Dec 13, 2018 at 11:38 PM Duy Nguyen [off-list ref] wrote:

quoted

Even with a new ref storage, I'm pretty sure pseudo refs like HEAD,
FETCH_HEAD... will forever be backed by filesystem. HEAD for example
is part of the repository signature and must exist as a file. We could
also lookup pseudo refs with readdir() instead of lstat(). On
case-preserving-and-insensitive filesystems, we can reject "head" this
way. But that comes with a high cost.
--
Duy

Once other refs are backed by something that doesn't depend on
filesystem case sensitivity, you could enforce that we only accept
call-caps HEAD as a psuedo ref, and always look up other spellings in
the other refs backend, though, right?

Hmm.. yes. I don't know off hand if we have any pseudo refs in
lowercase. Unlikely so yes this should work.

One thing we could do _today_ without waiting for a new refs backend
is, avoid looking up pseudo refs if the given ref name is not
all-caps. So "head" (or hEAd) can match refs/head, refs/tags/head,
refs/heads/head but never $GIT_DIR/HEAD. And yes I checked the code,
pseudo refs must be all-caps.
-- 
Duy