A branch from a sub-directory?

[Stefan Monnier]

> - reconstruct a new history via a process similar to "rebase".  This way
>   you can get rid of the history part that only affects "unrelated"
>   files, but you get a new branch unrelated to the old one.

Now I wonder: would it be possible for this new reconstructed branch to
be setup such that each commit has two parents: the usual one, plus one
from the original branch's corresponding revision?

I'm pretty sure the above is possible, but I guess my question is: would
this branch still need to contain all the info of the original branch
(just because it contains "parent commit pointers" to it)?


        Stefan