On Tue, 27 Mar 2007, Uwe Kleine-König wrote:
> 
> In the state above (i.e. linux-2.6 being a commit) the
> superproject's odb doesn't necessarily needs the object
> 0123456789abcde0, right.  But the commit before that had linux-2.6 being
> a tree.

Well, you're saying that somebody split an existing non-supermodule 
project?

If so, the supermodule really *does* have the old tree as its state, and 
sure, there will be duplication, but it's duplication that existed in the 
actual projects themselves, not something that the superproject 
introduced.

In other words, I don't think that's an argument for or against sharing 
the object database. You should *always* be able to share the object 
database by setting GIT_OBJECT_DIR if you want (or by using alternates). 
But that's independent of whether you are a sub/supermodule..

After all, if you generate two totally *separate* projects (no subproject 
at all) and they just shared some state on their own (say, git and xdiff 
both as totally independent git repositories), they have objects that can 
be in common. Do you want to use alternates or share an object database? 
Maybe, or maybe not. It depends on the user, not on whether it's a 
subproject.

		Linus