Re: `@` alias for `HEAD` not working in `git push -u origin @`

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 31, 2019, 16:10 UTC
Message-ID: <xmqqsgqmqj5k.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20190731055832.GA18039@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 15 quoted lines

> On Wed, Jul 10, 2019 at 11:39:37PM +0000, brian m. carlson wrote:
>
>> This is a bug. If the destination side of a refspec is omitted, and the
>> source side resolves to a ref starting with "refs/heads/" or
>> "refs/tags/" (which I expect it does here), then that ref is used as the
>> destination.
>> 
>> I submitted a patch at [0], but it was decided not to pick it up. If
>> Junio and the list decide that it's wanted, I'm happy to resend or
>> revise and resend.
>> 
>> [0] https://public-inbox.org/git/20180729192803.1047050-1-sandals@crustytoothpaste.net/
>
> I see I was cc'd on that original, but I don't remember ever reading it.
> It seems like a sane enough idea to me.

I see I was also on the cc list; I am not sure what I thought about the patch (i.e. implementation, not the desire to use '@' in the context in place for "HEAD") back then.

Now I read it with everything I thought forgotten, I see two potential issues:

 - Any error message downstream will mention "HEAD" and there won't
   be a trace of it originally being an "@" sign.  It may not be a
   problem, especially for those who _KNOW_ that they should be
   typing HEAD but can type "@" instead, but I am not sure what to
   do those who do not know much about "HEAD" and start from "@" (by
   the way, it is one reason why I do not like encouraging "@",
   especially in introductory text).

 - The code should update llen to 4; right now the remainder of the
   function does not use the variable in a way that the discrepancy
   of replacing "@" with "HEAD" without updating llen matters, but
   relying on the shape of the code that happens to exist right now
   is a bad code hygiene.

Other than that, the patch looks sensible to me.

Show 19 quoted lines

> Although I did notice that you mentioned there:
>
>> I probably type "git push upstream HEAD" from five to thirty times a
>> day
>
> I find I do that rarely, because I have:
>
>   [push]
>   default = current
>
> and in a triangular workflow, I have:
>
>   [remote]
>   pushDefault = upstream
>
> So "git push" without arguments typically does the same thing for me.
>
> Not an argument against your patch, but just something you might find
> useful.

That's a helpful tangent.  Thanks.