extensions.disabled: return {} instead of None no extensions are disabled

extensions.disabled: return {} instead of None no extensions are disabled

--- a/mercurial/extensions.py	Sun May 13 11:55:42 2012 +0200
+++ b/mercurial/extensions.py	Sun May 13 04:06:07 2012 -0500
@@ -274,7 +274,7 @@
 
     paths = _disabledpaths()
     if not paths:
-        return None
+        return {}
 
     exts = {}
     for name, path in paths.iteritems():