discovery: make revlogdag work on filtered repo

The revlogdag class is a core part of discovery. We need its initialisation to
exclude revision filtered out.

mercurial/dagutil.py

@@ -149,7 +149,7 b' class revlogdag(revlogbaseddag):'
     '''dag interface to a revlog'''
 
     def __init__(self, revlog):
-        revlogbaseddag.__init__(self, revlog, set(xrange(len(revlog))))
+        revlogbaseddag.__init__(self, revlog, set(revlog))
 
     def _getheads(self):
         return [r for r in self._revlog.headrevs() if r != nullrev]