Re: [PATCH/RFC] builtin-checkout: suggest creating local branch when appropriate to do so

> So we need the set of new rules, say, for 1.7.0 release.  A strawman?
>
> Assume that these are the only refs that exist:
>
>     refs/remotes/origin/{master,next,nitfol}
>     refs/remotes/xyzzy/{frotz,nitfol}
>     refs/heads/master

>     refs/tags/v1.0.0
>
> #0. These will stay as is:
>
>  $ git checkout mine               ;# switches to the branch
>  $ git checkout $any_committish^0  ;# detaches
>
> #1. These used to detach, but will create a local branch
>
>  $ git checkout origin/next        ;# as if with -t
>  $ git checkout xyzzy/frotz        ;# as if with -t (origin is not special)
>
> #2. These are allowed only when unambiguous and there is no local branch yet.
>
>  $ git checkout next               ;# ok
>  $ git checkout frotz              ;# ok (origin is not special)
>  $ git checkout nitfol             ;# not ok (ambiguous and origin is not special)
>
> #3. These used to detach, but what should we do?
>
>  $ git checkout v1.0.0             ;# detach, or refuse???
>  $ git checkout origin/master      ;# detach, or refuse???
>
> I can buy 0, 1, and 2, and I think it is a minor inconvenience if we
> started refusing to detach in case #3, as people who want to detach can
> always suffix ^0 or ~0 to make it a general committish.
>
> Did I cover all cases?