rebase: allow rebasing children of wd to wd if a new branch has been set (BC)...
rebase: allow rebasing children of wd to wd if a new branch has been set (BC)
The named branch of the leaf changeset can be changed by updating to it,
setting the branch, and amending.
But previously, there was no good way to *just* change the branch of several
linear changes. If rebasing changes with another parent to '.', it would pick
up a pending branch change up. But when rebasing changes that have the same
parent, it would fail with 'nothing to rebase', even when the branch name was
set differently.
To fix this, allow rebasing to same parent when a branch has been set.
