Re: [PATCH] http-backend: respect GIT_NAMESPACE with dumb clients

From: Junio C Hamano <gitster@pobox.com>
Date: Apr 5, 2013, 05:34 UTC
Message-ID: <7vobdtee12.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20130405025655.GA25970@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 20 quoted lines

> Yeah, that makes sense. I think we'd want something like the (totally
> untested) patch below. And the tests I provided for t5551 should be
> amended to set up a HEAD within the namespace, should make the resulting
> clone non-bare, and should confirm that we check out the correct HEAD.
>
> diff --git a/http-backend.c b/http-backend.c
> index 8144f3a..84ba7f9 100644
> --- a/http-backend.c
> +++ b/http-backend.c
> @@ -376,6 +376,14 @@ static int show_text_ref(const char *name, const unsigned char *sha1,
>  	return 0;
>  }
>  
> +static void get_head(char *arg)
> +{
> +	struct strbuf buf = STRBUF_INIT;
> +	head_ref_namespaced(show_text_ref, &buf);
> +	send_strbuf("text/plain", &buf);
> +	strbuf_release(&buf);
> +}

You identified the right place to patch, but I think we need a bit more than this.

The show_text_ref() function gives "SHA-1 <TAB> refname". It is likely that the dumb client will ignore the trailing part of that output, but let's avoid a hack that we would not want see other implementations imitate.

One advantage dumb clients has over smart ones is that they can read HEAD that is a textual symref from a dumb server and learn which branch is the default one (remote.c::guess_remote_head()) without guessing. I think this function should:

 - Turn "HEAD" into a namespaced equivalent;

 - Run resolve_ref() on the result of the above;

 - Is it a symbolic ref?

   . If it is, then format "ref: <target>\n" into a strbuf and send
     it (make sure <target> is without the namespace prefix);

   . Otherwise, HEAD is detached. Prepare "%s\n" % sha1_to_hex(sha1),
     and send it.