diff -r 762c8a128357 -r c1149533676b mercurial/mergeutil.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mercurial/mergeutil.py	Mon Nov 21 21:31:45 2016 -0500
@@ -0,0 +1,22 @@
+# mergeutil.py - help for merge processing in mercurial
+#
+# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
+#
+# 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
+
+from .i18n import _
+
+from . import (
+    error,
+)
+
+def checkunresolved(ms):
+    if list(ms.unresolved()):
+        raise error.Abort(_("unresolved merge conflicts "
+                            "(see 'hg help resolve')"))
+    if ms.mdstate() != 's' or list(ms.driverresolved()):
+        raise error.Abort(_('driver-resolved merge conflicts'),
+                          hint=_('run "hg resolve --all" to resolve'))