--- a/mercurial/revset.py	Wed Dec 04 13:42:28 2013 -0600
+++ b/mercurial/revset.py	Sat Dec 21 12:44:19 2013 +0900
@@ -1880,7 +1880,9 @@
         aliases[alias.name] = alias
     return _expandaliases(aliases, tree, [], {})
 
-parse = parser.parser(tokenize, elements).parse
+def parse(spec):
+    p = parser.parser(tokenize, elements)
+    return p.parse(spec)
 
 def match(ui, spec):
     if not spec: