diff -r 8ab7de07f40e -r f9b0e4f023c4 mercurial/merge.py
--- a/mercurial/merge.py	Thu Oct 04 14:23:28 2007 +0200
+++ b/mercurial/merge.py	Mon Oct 08 18:47:22 2007 -0500
@@ -177,7 +177,7 @@
                 continue
             # named changed on only one side?
             if ca.path() == c.path() or ca.path() == c2.path():
-                if c == ca or c2 == ca: # no merge needed, ignore copy
+                if c == ca and c2 == ca: # no merge needed, ignore copy
                     continue
                 copy[c.path()] = of
 
@@ -254,7 +254,7 @@
 
 def symmetricdifference(repo, rev1, rev2):
     """symmetric difference of the sets of ancestors of rev1 and rev2
-    
+
     I.e. revisions that are ancestors of rev1 or rev2, but not both.
     """
     # basic idea: