diff -r 76b334b9f45c -r 100814e14b77 mercurial/exchange.py
--- a/mercurial/exchange.py	Sat Sep 30 07:43:40 2017 -0400
+++ b/mercurial/exchange.py	Sat Sep 30 07:43:53 2017 -0400
@@ -1417,7 +1417,6 @@
 
 def _pullbundle2extraprepare(pullop, kwargs):
     """hook function so that extensions can extend the getbundle call"""
-    pass
 
 def _pullchangeset(pullop):
     """pull changeset from unbundle into the local repo"""