On Mon, Feb 27, 2017 at 01:44:26PM -0800, Junio C Hamano wrote:
> Junio C Hamano <gitster@xxxxxxxxx> writes:
>
> > ... I suspect that calling interpret_empty_at() from
> > that function is fundamentally flawed. The "@" end user types never
> > means refs/heads/HEAD, and HEAD@{either reflog or -1} would not mean
> > anything that should be taken as a branch_name, either.
>
> The latter should read "HEAD@{either reflog or -1 or 'upstream'}"
>
> Or do we make HEAD@{upstream} to mean "deref HEAD to learn the
> current branch name and then take its upstream"? If so @@{upstream}
> might logically make sense, but I do not see why @{upstream} without
> HEAD or @ is not sufficient to begin with, so...
Yes, HEAD@{upstream} and @@{upstream} are both resolved to the actual
branch name. I also was puzzled whether there was any real use over just
@{upstream}. But it does work, and if you had a script which looked for,
say, $branch@{upstream}, you'd probably want branch=HEAD to keep
working.
The "branch=@" case I am less sympathetic to, as it was mainly supposed
to be a command-line convenience. But it _does_ work now.
-Peff