Re: [Bug] Porcelain allows creation of '@' branch

["Kristoffer Haugsbakk" <kristofferhaugsbakk@fastmail.com>]

On Mon, Aug 31, 2026, at 21:59, D. Ben Knoble wrote:
> On Mon, Aug 31, 2026 at 3:12 PM Bence Csókás <bence.csokas@arm.com> wrote:
>>
>> Hi,
>>
>> I ran into this issue a few weeks ago. I'm using Git 2.55.0, which is
>> the latest released.
>>
>> `git help check-ref-format` says this about a branch name:
>>
>>    [...]
>>    9. They cannot be the single character @.
>>    [...]
>
> This is the rule for a reference.
>
>> And as expected, it is rejected:
>>
>>    $ git check-ref-format @ && echo BUG!
>>    $
>>
>> However, the following commands all create a branch named @ :
>>
>>    $ git checkout -b @
>>    $ git switch -c @
>>    $ git branch @
>
> But (with git refs list) we should see this creates a ref "refs/heads/@".
>
> I happen to think that's extremely confusing given that "@" is the
> shorthand for HEAD, but… it's not against the current documented
> rules, I think. (e.g., "git switch @" will fail, since it sees "git
> switch HEAD"; using "refs/heads/@" will also fail.) git-checkout
> doesn't fail but also doesn't change to the "@" branch. Futzing with
> .git/HEAD and restoring the working tree works, but… yikes.
>
> Of course, --branch mode is allowed to be stricter; maybe we should
> reject this case?

Not a bug (2024) https://lore.kernel.org/git/xmqqy12z7eti.fsf@gitster.g/

    I suspect that it is much more productive to deprecate and remove
    "@" that is a built-in synomym for HEAD (but "refs/remotes/origin/@"
    does not act as a synonym for "refs/remotes/origin/HEAD"). [...]

>[snip]