--- a/mercurial/dirstate.py	Tue Mar 31 23:32:27 2015 -0700
+++ b/mercurial/dirstate.py	Wed Apr 01 00:44:33 2015 -0700
@@ -88,6 +88,14 @@
 
     @propertycache
     def _filefoldmap(self):
+        try:
+            makefilefoldmap = parsers.make_file_foldmap
+        except AttributeError:
+            pass
+        else:
+            return makefilefoldmap(self._map, util.normcasespec,
+                                   util.normcasefallback)
+
         f = {}
         normcase = util.normcase
         for name, s in self._map.iteritems():