diff --git a/mercurial/dirstate.py b/mercurial/dirstate.py
--- a/mercurial/dirstate.py
+++ b/mercurial/dirstate.py
@@ -300,6 +300,8 @@
                         return b''
                 return fallback(x)
 
+            return f
+
     @propertycache
     def _cwd(self):
         # internal config: ui.forcecwd