how do I commit somewhere other than onto a tip?

[Stephen J. Turnbull]

Vincent Broman writes:

 > Meinel suggested something similar, but here is the problem:
 > Say I have versions A,B,C
 > 
 > A -> B -> C
 > 
 > Now I commit AA which is supposed to be a successor of A and predecessor of B.
 > 
 > A      -> B -> C
 >  -> AA
 > 

Do it in git, which is designed for precisely this kind of surgery on
commit DAGs.  Then use tailor or similar to transform the git repo to
a bzr repo, and go forth and sin no more after that.