Re: Bug: "git checkout -b" should be allowed in empty repo

From: Michael Haggerty <mhagger@alum.mit.edu>
Date: Feb 6, 2012, 08:59 UTC
Message-ID: <4F2F9661.2020606@alum.mit.edu>
In-Reply-To: <7vk440a5qw.fsf@alter.siamese.dyndns.org>

On 02/06/2012 06:30 AM, Junio C Hamano wrote:

Show 27 quoted lines

> Jeff King <peff@peff.net> writes:
> 
>> Sure, that's one way to do it. But I don't see any point in not allowing
>> "git checkout -b" to be another way of doing it. Is there some other use
>> case for "git checkout -b" from an unborn branch? Or is there some
>> harmful outcome that can come from doing so that we need to be
>> protecting against? Am I missing something?
> 
> Mostly because it is wrong at the conceptual level to do so.
> 
> 	git checkout -b foo
> 
> is a short-hand for
> 
> 	git checkout -b foo HEAD
> 
> which is a short-hand for
> 
> 	git branch foo HEAD &&
>         git checkout foo
> 
> But the last one has no chance of working if you think about it, because
> "git branch foo $start" is a way to start a branch at $start and you need
> to have something to point at with refs/heads/foo.
> 
> So we are breaking the equivalence between these three only when HEAD
> points at an unborn branch.

You are thinking too much like a developer and not like a user.  For a user,

    git checkout -b foo

is a short-hand for

    "create and check out a branch at my current state"

and the interpretation of what that means when I am on an unborn branch seems unambiguous.

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/