extensions: use _order to determine if an extension is enabled

extensions: use _order to determine if an extension is enabled

--- a/mercurial/extensions.py	Sun Jun 21 17:18:48 2009 +0200
+++ b/mercurial/extensions.py	Sun Jun 21 17:19:34 2009 +0200
@@ -138,17 +138,10 @@
             if not os.path.exists(path):
                 continue
 
-        if name in exts or name == '__init__':
+        if name in exts or name in _order or name == '__init__':
             continue
 
         try:
-            find(name)
-        except KeyError:
-            pass
-        else:
-            continue # enabled extension
-
-        try:
             file = open(path)
         except IOError:
             continue