Re: How to specify remote branch correctly

[Woody Wu <narkewoody@gmail.com>]

On 2012-12-17, Andrew Ardill <andrew.ardill@gmail.com> wrote:
> On 17 December 2012 16:06, Woody Wu <narkewoody@gmail.com> wrote:
>> 1. git checkout foo.
>> By this command, I think I am checking out files in my local branch
>> named foo, and after that I also switch to the branch. Right?
>
> Correct. Your working directory (files) switch over to whatever your
> local branch 'foo' points to, and your HEAD is updated to point to
> your local branch 'foo'. Unless something goes wrong/you have
> conflicting files/uncommitted changes etc.
>
>> 2. git checkout origin/foo
>> By this command, I am checking out files in remote branch origin/foo,
>> but don't create a local branch, so I am not in any branch now. This is
>> the reason why git tell me that I am in a 'detached HEAD'. Is this
>> understanding right?
>
> Correct! Your working directory is updated, however it doesn't make
> sense for you to make changes to a remote branch, so HEAD is updated
> to be detached.
>
>>>
>>> There are lots of patterns that can emerge from this functionality,
>>> but the main thing to remember is that to create changes on top of a
>>> remote branch, we first need to create a local copy of it. A 'detached
>>> HEAD' here means that we are looking at the remote repository's branch
>>> but don't have a local copy of it, so any changes we make might be
>>> 'lost' (that is, not have an easy to find branch name).
>>>
>>
>> I think here is a little confuse to me.  You mean that a 'detached HEAD'
>> means I don't have a local copy, but I remember that if I run something
>> like:
>>     $ git checkout a-tag-name
>> then I ususally went into 'detached HEAD' but my local files really get
>> switched to those files in the tag 'a-tag-name'.  So what does you mean
>> by 'don't have a local copy'?
>
> I should have been more clear. Here I mean that you don't have a local
> copy of the branch reference. Your working directory is updated to be
> in sync with the remote branch, but you haven't yet copied that remote
> reference to a local branch that you can update with your changes.
>
> Hope that clears it up.
>

Andre, by this in further exaplaination, I think I fully understood.
Thanks a lot!

-- 
woody
I can't go back to yesterday - because I was a different person then.