mercurial/context.py

--- a/mercurial/context.py	Tue May 27 17:41:20 2014 -0700
+++ b/mercurial/context.py	Fri Sep 20 21:55:42 2013 -0500
@@ -132,6 +132,9 @@
     def substate(self):
         return subrepo.state(self, self._repo.ui)
 
+    def subrev(self, subpath):
+        return self.substate[subpath][1]
+
     def rev(self):
         return self._rev
     def node(self):