diff -r f0efd2bffe1e -r b82615afde65 mercurial/bundle2.py
--- a/mercurial/bundle2.py	Thu Jun 22 15:59:07 2017 -0700
+++ b/mercurial/bundle2.py	Fri Jun 16 10:25:11 2017 -0700
@@ -310,6 +310,10 @@
     to be created"""
     raise TransactionUnavailable()
 
+def applybundle1(repo, cg, tr, source, url, **kwargs):
+    ret, addednodes = cg.apply(repo, tr, source, url, **kwargs)
+    return ret
+
 def applybundle(repo, unbundler, tr, source=None, url=None):
     # transform me into unbundler.apply() as soon as the freeze is lifted
     tr.hookargs['bundle2'] = '1'