--- a/hgext/fetch.py	Fri Dec 30 14:31:59 2011 -0600
+++ b/hgext/fetch.py	Fri Dec 30 15:07:05 2011 -0600
@@ -102,6 +102,9 @@
                       (len(newheads) - 1))
             return 1
 
+        if not newheads:
+            return 0
+
         # Otherwise, let's merge.
         err = False
         if newheads: