Re: [PATCH v4 1/5] refs: introduce `is_pseudoref()` and `is_headref()`

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 12, 2024, 17:01 UTC
Message-ID: <xmqqeddh7h2l.fsf@gitster.g>
In-Reply-To: <ZcoTbRxIaGmTd4fJ@tanuki>

Patrick Steinhardt <ps@pks.im> writes:

> I think it's quite confusing that `is_pseudoref()` not only checks
> whether the refname may be a pseudoref, but also whether it actually
> exists. Furthermore, why is a pseudoref only considered to exist in case
> it's not a symbolic ref? That sounds overly restrictive to me.

I am torn on this, but in favor of the proposed naming, primarily because is_pseudoref_syntax() was about "does this string look like the fullref a pseudoref would have?", and the reason why we wanted to have this new function was we wanted to ask "does this string name a valid pseudoref?"

 Q: Is CHERRY_PICK_HEAD a pseudoref?
 A: It would have been if it existed, but I see only
    $GIT_DIR/CHERRY_PICK_HEAD that is a symbolic link, and it cannot
    be a pseudoref.

I can certainly see a broken out set of helper functions to check

 - Does this string make a good fullref for a pseudoref?
 - Does a pseudoref with his string as its fullref exist?

independently. The first one would answer Yes and the second one would answer No in such a context.

Thanks.