diff -r d90b0b30464b -r 95174c381525 mercurial/subrepo.py
--- a/mercurial/subrepo.py	Wed Nov 09 19:46:49 2011 -0500
+++ b/mercurial/subrepo.py	Wed Nov 09 19:46:51 2011 -0500
@@ -360,6 +360,9 @@
         '''
         pass
 
+    def forget(self, files):
+        pass
+
 class hgsubrepo(abstractsubrepo):
     def __init__(self, ctx, path, state):
         self._path = path
@@ -553,6 +556,10 @@
         ctx = self._repo[None]
         return ctx.walk(match)
 
+    def forget(self, files):
+        ctx = self._repo[None]
+        ctx.forget(files)
+
 class svnsubrepo(abstractsubrepo):
     def __init__(self, ctx, path, state):
         self._path = path