diff -r 8a2156780839 -r d8330fb8c44d mercurial/patch.py
--- a/mercurial/patch.py	Mon Feb 02 23:07:04 2015 +0900
+++ b/mercurial/patch.py	Thu Jan 29 21:12:35 2015 -0800
@@ -1788,13 +1788,12 @@
     if opts.git:
         revs = None
 
-    modifiedset, addedset, removedset = set(modified), set(added), set(removed)
-    # Fix up modified and added, since merged-in additions appear as
+    addedset, removedset = set(added), set(removed)
+    # Fix up  added, since merged-in additions appear as
     # modifications during merges
-    for f in modifiedset.copy():
+    for f in modified:
         if f not in ctx1:
             addedset.add(f)
-            modifiedset.remove(f)
     for f in sorted(modified + added + removed):
         to = None
         tn = None