diff -r 4277e20cfec4 -r e10adebf8176 mercurial/context.py
--- a/mercurial/context.py	Mon Dec 17 15:05:52 2018 +0100
+++ b/mercurial/context.py	Tue Dec 18 10:21:25 2018 -0500
@@ -2330,6 +2330,9 @@
         if copied:
             self._copied = (copied, nullid)
 
+    def cmp(self, fctx):
+        return self.data() != fctx.data()
+
     def data(self):
         return self._data