diff -r 91f3ac205816 -r 1093ad1e8903 mercurial/revlog.py
--- a/mercurial/revlog.py	Fri Jun 01 12:37:18 2012 -0700
+++ b/mercurial/revlog.py	Fri Jun 01 12:45:16 2012 -0700
@@ -398,7 +398,7 @@
                     seen.add(parent)
                     yield parent
 
-    def descendants(self, *revs):
+    def descendants(self, revs):
         """Generate the descendants of 'revs' in revision order.
 
         Yield a sequence of revision numbers starting with a child of
@@ -700,7 +700,7 @@
     def descendant(self, start, end):
         if start == nullrev:
             return True
-        for i in self.descendants(start):
+        for i in self.descendants([start]):
             if i == end:
                 return True
             elif i > end: