diff -r 6a0018cdb2fe -r d2504744e7a5 mercurial/config.py
--- a/mercurial/config.py	Sun Apr 26 16:50:43 2009 -0500
+++ b/mercurial/config.py	Sun Apr 26 16:50:43 2009 -0500
@@ -6,8 +6,6 @@
     def __init__(self, data=None):
         self._list = []
         if data:
-            if hasattr(data, '_list'):
-                self._list = list(data._list)
             self.update(data)
     def copy(self):
         return sortdict(self)