mercurial/context.py

--- a/mercurial/context.py	Fri Jun 01 12:37:18 2012 -0700
+++ b/mercurial/context.py	Fri Jun 01 12:45:16 2012 -0700
@@ -227,7 +227,7 @@
             yield changectx(self._repo, a)
 
     def descendants(self):
-        for d in self._repo.changelog.descendants(self._rev):
+        for d in self._repo.changelog.descendants([self._rev]):
             yield changectx(self._repo, d)
 
     def _fileinfo(self, path):