diff -r e8c0b52c363c -r b8076522e889 mercurial/commands.py
--- a/mercurial/commands.py	Wed Jul 18 13:56:08 2007 -0700
+++ b/mercurial/commands.py	Wed Jul 18 14:00:55 2007 -0700
@@ -2018,7 +2018,7 @@
         return
     if optupdate:
         if modheads == 1:
-            return hg.update(repo, repo.changelog.tip()) # update
+            return hg.update(repo, None)
         else:
             ui.status(_("not updating, since new heads added\n"))
     if modheads > 1: