Re: [PATCH] t6300: avoid creating refs/heads/HEAD

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 27, 2017, 19:33 UTC
Message-ID: <xmqqzih7whrw.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20170227092931.7iquwaxomeuuusi2@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> This comes originally from Junio's 84679d470. I cannot see how naming
> the new branch HEAD would make any difference to the test, but perhaps I
> am missing something.

Nah, I think it was just a random string that came to mind and the topic being "ah we blindly dereference something when showing %(HEAD)" it was plausible I thought of "H E A D" as that random string before I used my usual other random strings like frotz ;-)

> I noticed this while digging on a nearby issue around "git branch -m @".
> This does happen to be the only test that checks that we can make a
> branch called refs/heads/HEAD, and I found it because it triggers if you
> try to disallow "git branch -m HEAD". :)

About that "nearby" one, does it even make sense to do the interpret thing on the <new> name? I can understand "please rename the branch I was previously on to this new name" wanting to say @{-1} when the user does not recall the exact spelling of a long name, but I do not quite see how "to this new name" part benefits by the "interpret branch name" magic in the first place.

> If we care about that, though, I think we should make an explicit test
> for "git branch HEAD". But I'm not sure we _do_ care about that. Making
> a branch called HEAD is moderately insane, and I don't think it would be
> unreasonable for us to outlaw it at some point.

Yeah, at that point we would have "test_must_fail git branch HEAD".

Show 16 quoted lines

>  t/t6300-for-each-ref.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
> index aea1dfc71..a468041c5 100755
> --- a/t/t6300-for-each-ref.sh
> +++ b/t/t6300-for-each-ref.sh
> @@ -558,7 +558,7 @@ test_expect_success 'do not dereference NULL upon %(HEAD) on unborn branch' '
>  	test_when_finished "git checkout master" &&
>  	git for-each-ref --format="%(HEAD) %(refname:short)" refs/heads/ >actual &&
>  	sed -e "s/^\* /  /" actual >expect &&
> -	git checkout --orphan HEAD &&
> +	git checkout --orphan orphaned-branch &&
>  	git for-each-ref --format="%(HEAD) %(refname:short)" refs/heads/ >actual &&
>  	test_cmp expect actual
>  '