--- a/mercurial/revset.py	Mon Oct 27 23:47:41 2014 -0500
+++ b/mercurial/revset.py	Tue Oct 28 14:06:06 2014 -0700
@@ -2500,7 +2500,7 @@
         return len(self._list)
 
     def __nonzero__(self):
-        return bool(self._r1 or self._r2)
+        return bool(self._r1) or bool(self._r2)
 
     @util.propertycache
     def _list(self):