Re: [PATCH] clone: fix refspec on "--single-branch" option

[Junio C Hamano <gitster@pobox.com>]

Ralf Thielow <ralf.thielow@gmail.com> writes:

> After using "git clone" with the "--single-branch"
> option, the configured refspec for this repo was
> "+refs/heads/*:refs/remotes/origin/*".
> After fetching changes from this repo again, it'll
> receive all refs instead of the single ref which
> was used in "--single-branch". Fixing the refspec
> that it just contains the ref of the branch which
> was cloned.
>
> Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
> ---
>  builtin/clone.c | 5 ++++-
>  1 Datei geändert, 4 Zeilen hinzugefügt(+), 1 Zeile entfernt(-)
>
> diff --git a/builtin/clone.c b/builtin/clone.c
> index 5e8f3ba..3e74d55 100644
> --- a/builtin/clone.c
> +++ b/builtin/clone.c
> @@ -754,7 +754,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
>  		strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
>  	}
>  
> -	strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
> +	if (option_single_branch)
> +		strbuf_addf(&value, "+%s%s:%s%s", src_ref_prefix, option_branch, branch_top.buf, option_branch);
> +	else
> +		strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);

Who guarantees at this point in the codepath that option_branch is
set when option_single_branch is non-zero?  Until we talk with the
remote, "clone --single-branch" without an explicit "--branch" will
not learn which branch at the remote we are going to fetch (it will
be their HEAD).

I wonder if this should be more like this:

	if (option_single_branch) {
		if (option_branch)
			Your patch "+refs/heads/foo:refs/remotes/origin/foo";
		else
			"HEAD";
        } else {
        	Original "+refs/heads/*:refs/remotes/origin/*";
	}

That is, "clone --single-branch" will continue fetching from and
integrating with their HEAD without storing any remote tracking
branch.