diff -r 3d1baa702d1a -r 5c0fd878779c mercurial/changegroup.py
--- a/mercurial/changegroup.py	Wed Jan 06 20:05:18 2016 +0000
+++ b/mercurial/changegroup.py	Fri Jan 08 21:13:06 2016 -0800
@@ -1046,17 +1046,6 @@
         directory = (f[-1] == '/')
         if directory:
             # a directory using treemanifests
-            # TODO fixup repo requirements safely
-            if 'treemanifest' not in repo.requirements:
-                if not wasempty:
-                    raise error.Abort(_(
-                        "bundle contains tree manifests, but local repo is "
-                        "non-empty and does not use tree manifests"))
-                repo.requirements.add('treemanifest')
-                repo._applyopenerreqs()
-                repo._writerequirements()
-                repo.manifest._treeondisk = True
-                repo.manifest._treeinmem = True
             fl = repo.manifest.dirlog(f)
         else:
             fl = repo.file(f)