Code review comment for lp:~zyga/bzr/find_ancestors

Thanks for having a go at fixing this.

To land, this branch really needs:
* Tests, to demonstrate the problem and evaluate any attempted fix against
* Logic, rather than than just raising NotImplementedError and skipping that case

Did you have a look at Wouter's branch, which implements the method? Does that also work for you?

<lp:~larstiq/bzr/bug541626>

If so, picking up that code and writing a test case that exercises it would be a good way forwards.