switching versioning from distro only to distro+upstream

[James Westby]

On Wed, 2008-03-19 at 10:28 +0100, Stefano Zacchiroli wrote:
> What I would need is the ability to create a separate history line from
> scratch, call it "usptream", tie it with the master history with a new
> (fake) commit root, and then merge the two into master. Is that possible
> with git or some other $DVCS?

git itself has this in it's history with the "todo" branch. 
Unfortunately, I can't find you a reference to the instructions to do
this at the moment, perhaps someone else can provide them.

Thanks,

James