diff -r e1ecfc7c84be -r b4057d001760 mercurial/copies.py
--- a/mercurial/copies.py	Fri Jan 31 08:47:32 2020 -0800
+++ b/mercurial/copies.py	Wed Jan 22 13:29:26 2020 -0800
@@ -537,10 +537,7 @@
             return
         # modified on side 2
         for dst in dsts1:
-            if dst not in m2:
-                # dst not added on side 2 (handle as regular
-                # "both created" case in manifestmerge otherwise)
-                copy[dst] = src
+            copy[dst] = src
 
 
 class branch_copies(object):