diff -r 6955d69a52a4 -r 59c14bf5a48c mercurial/pushkey.py
--- a/mercurial/pushkey.py	Sat Jul 28 13:05:25 2012 +0200
+++ b/mercurial/pushkey.py	Sat Jul 28 13:33:06 2012 +0200
@@ -11,6 +11,8 @@
     n = {}
     for k in _namespaces:
         n[k] = ""
+    if not obsolete._enabled:
+        n.pop('obsolete')
     return n
 
 _namespaces = {"namespaces": (lambda *x: False, _nslist),