stablesort: simplify processing of non-merge changesets As long as a changeset as only one parent, the next element in the sort (starting from the head) has to be that parent. We detect and take advantage of that shortcut in the non-merge case.

# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)