diff -r ee2e4a2c3690 -r 92d37fb3f1aa mercurial/context.py
--- a/mercurial/context.py	Thu Apr 28 08:52:13 2016 -0700
+++ b/mercurial/context.py	Wed Apr 27 22:45:52 2016 -0400
@@ -275,9 +275,9 @@
         except error.LookupError:
             return ''
 
-    def sub(self, path):
+    def sub(self, path, allowcreate=True):
         '''return a subrepo for the stored revision of path, never wdir()'''
-        return subrepo.subrepo(self, path)
+        return subrepo.subrepo(self, path, allowcreate=allowcreate)
 
     def nullsub(self, path, pctx):
         return subrepo.nullsubrepo(self, path, pctx)