--- a/mercurial/cmdutil.py	Sat Jan 03 10:25:08 2015 +0900
+++ b/mercurial/cmdutil.py	Mon Jan 05 22:18:55 2015 -0800
@@ -1072,7 +1072,7 @@
                           ", ".join('"%s": "%s"' % (j(k), j(v))
                                     for k, v in ctx.extra().items()))
 
-            files = ctx.status(ctx.p1())
+            files = ctx.p1().status(ctx)
             self.ui.write(',\n  "modified": [%s]' %
                           ", ".join('"%s"' % j(f) for f in files[0]))
             self.ui.write(',\n  "added": [%s]' %