--- a/mercurial/filelog.py	Mon Sep 24 09:38:27 2018 -0700
+++ b/mercurial/filelog.py	Thu Sep 20 19:31:07 2018 -0700
@@ -25,8 +25,6 @@
         # Full name of the user visible file, relative to the repository root.
         # Used by LFS.
         self._revlog.filename = path
-        # Used by repo upgrade.
-        self.index = self._revlog.index
         # Used by changegroup generation.
         self._generaldelta = self._revlog._generaldelta