prev: allow to update to 't0' from 't1'
When on the first changeset of a topic, one can move back one changeset to end
up on t0. The new working copy parent to not belong to the topic, but the topic
is still active. The next commit will create a new root to the active topic.
You can get the same result using `hg up t0`
This software was downloaded from
https://www.mercurial-scm.org/repo/evolve/
Copyright 2011 Peter Arrenbrecht <peter.arrenbrecht@gmail.com>
Logilab SA <contact@logilab.fr>
Pierre-Yves David <pierre-yves.david@ens-lyon.org>
Patrick Mezard <patrick@mezard.eu>
This software may be used and distributed according to the terms of the GNU
General Public License version 2 or any later version.
On Debian systems, the complete text of the GNU General Public License version
2 can be found in `/usr/share/common-licenses/GPL-2'.