diff -r c93ca83a3354 -r cfebb175704f mercurial/copies.py
--- a/mercurial/copies.py	Sat Mar 15 16:24:16 2008 -0500
+++ b/mercurial/copies.py	Sat Mar 15 16:25:27 2008 -0500
@@ -68,7 +68,7 @@
     pr = repo.changelog.parentrevs
     def parents(rev):
         return [p for p in pr(rev) if p != nullrev]
-    limit = min(ancestor.symmetricdifference(rev1, rev2, parents))
+    limit = min(ancestor.symmetricdifference(rev1, rev2, parents) + [rev1, rev2])
     m1 = c1.manifest()
     m2 = c2.manifest()
     ma = ca.manifest()