diff -r 770128405002 -r 548fa75cdb07 mercurial/context.py
--- a/mercurial/context.py	Sun Aug 21 12:36:23 2016 +0900
+++ b/mercurial/context.py	Sat Sep 10 01:41:38 2016 +0200
@@ -528,7 +528,7 @@
 
     @propertycache
     def _manifest(self):
-        return self._repo.manifestlog[self._changeset.manifest].read()
+        return self._repo.manifestlog[self._changeset.manifest]
 
     @propertycache
     def _manifestdelta(self):