--- a/hgext/obsolete.py	Mon Apr 16 10:51:40 2012 +0200
+++ b/hgext/obsolete.py	Fri Apr 20 17:12:38 2012 +0200
@@ -157,7 +157,7 @@
     nm = repo.changelog.nodemap
     for r in s:
         for p in repo._obssubrels.get(repo[r].node(), ()):
-            pr = nm.get(p, None)
+            pr = nm.get(p)
             if pr is not None:
                 cs.add(pr)
     return cs
@@ -181,7 +181,7 @@
     nm = repo.changelog.nodemap
     cs = set()
     for p in seen:
-        pr = nm.get(p, None)
+        pr = nm.get(p)
         if pr is not None:
             cs.add(pr)
     return cs