ancestor: use absolute_import A few months ago, import-checker.py was taught to enforce a more well-defined import style for files with absolute_import. However, we stopped short of actually converting source files to use absolute_import because of problems with certain files. Investigation revealed the following problems with switching to absolute_import universally: 1) import cycles result in import failure on Python 2.6 2) undetermined way to import C/pure modules While these problems need to be solved, they can be put off. This patch starts a series of converting files to absolute_import that won't exhibit any of the aforementioned problems.

--- a/mercurial/ancestor.py	Wed Aug 05 14:21:46 2015 -0400
+++ b/mercurial/ancestor.py	Fri Aug 07 19:45:48 2015 -0700
@@ -5,9 +5,12 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
+from __future__ import absolute_import
+
 import collections
 import heapq
-from node import nullrev
+
+from .node import nullrev
 
 def commonancestorsheads(pfunc, *nodes):
     """Returns a set with the heads of all common ancestors of all nodes,