--- a/mercurial/manifest.py Sun Feb 18 00:43:50 2018 -0500
+++ b/mercurial/manifest.py Sun Feb 18 00:49:11 2018 -0500
@@ -960,7 +960,7 @@
else:
files.update(m1.iterkeys())
- for fn in t1._files.iterkeys():
+ for fn in t1._files:
if fn not in t2._files:
files.add(t1._subpath(fn))