diff -r 371cff9610cd -r 0bd17a4bed88 mercurial/patch.py
--- a/mercurial/patch.py	Tue Jan 03 17:13:03 2012 -0600
+++ b/mercurial/patch.py	Wed Jan 04 15:48:02 2012 -0600
@@ -1600,7 +1600,7 @@
 
     copy = {}
     if opts.git or opts.upgrade:
-        copy = copies.copies(repo, ctx1, ctx2, repo[nullid])[0]
+        copy = copies.pathcopies(ctx1, ctx2)
 
     difffn = lambda opts, losedata: trydiff(repo, revs, ctx1, ctx2,
                  modified, added, removed, copy, getfilectx, opts, losedata, prefix)