Re: git submodule support feedback

[Junio C Hamano <junkio@cox.net>]

Andy Parkins <andyparkins@gmail.com> writes:

> On Thursday 2007, April 26, Andy Parkins wrote:
>
>> I'll report further as I come across any stumbling blocks; but here
>
> The submodule support requires the latest version of git right?  That's 
> going to cause trouble for people running different versions of git 
> (I've already experienced it in my own limited way - I had to upgrade 
> all the copies of git I have on my various computers before fetching 
> and pushing would work).  If the repository contains a submodule 
> reference it effectively becomes inaccessible by a version of git 
> without submodule support.
>
> I think that we might be able to avoid that problem though - am I right 
> in thinking that the problem is that all the tools need teaching not to 
> follow the gitlink object because that hash doesn't exist in _this_ 
> tree it is a reference to a commit in another tree.
>
> Wouldn't it be better if the gitlink reference pointed at an object in 
> this tree which in turn referred to the submodule commit?  That way the 
> old versions of git would still work with submodule objects in the 
> repository because they would just see submodules as pointing at a 
> blob.
>
> Have I oversimplified it in my head?

I think older tools do not expect to find anything but tree or
blob in a tree object to begin with.  Now your experimental
repository has a commit, which they do not expect to see and I
think they will be unhappy.

If you replace the commit objects in your trees with a new type
of object 'gitlink', your older tools will have exactly the same
problem, won't they?