evolve: refactor the code which swap two nodes (in divergence resolution)
I see that we are using the code to swap the "divergent" and "other" node;
and updating the evolvestate accordingly at many places in divergence
resolution. This patch extract that code to a function.
Although I don't have strong opinion on this patch. It's a volunteered
patch to remove some redundancy.
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'.