mercurial/fancyopts.py

--- a/mercurial/fancyopts.py	Tue May 12 10:03:36 2009 -0400
+++ b/mercurial/fancyopts.py	Wed May 13 14:08:39 2009 +0200
@@ -70,7 +70,7 @@
         # copy defaults to state
         if isinstance(default, list):
             state[name] = default[:]
-        elif callable(default):
+        elif hasattr(default, '__call__'):
             state[name] = None
         else:
             state[name] = default