backout: don't limit heritage check to a single ancestor
This do probably not make any real difference but is slightly more correct and
we would like to get rid of changelog.ancestor.
--- a/mercurial/commands.py Thu Mar 20 01:35:07 2014 +0100
+++ b/mercurial/commands.py Mon Apr 07 23:17:51 2014 +0200
@@ -438,8 +438,7 @@
node = scmutil.revsingle(repo, rev).node()
op1, op2 = repo.dirstate.parents()
- a = repo.changelog.ancestor(op1, node)
- if a != node:
+ if node not in repo.changelog.commonancestors(op1, node):
raise util.Abort(_('cannot backout change that is not an ancestor'))
p1, p2 = repo.changelog.parents(node)