diff -r e7bf09acd410 -r e825a89de5d7 mercurial/revset.py
--- a/mercurial/revset.py	Sun May 13 14:04:04 2012 +0200
+++ b/mercurial/revset.py	Sun May 13 14:04:06 2012 +0200
@@ -395,7 +395,7 @@
     """
     # i18n: "closed" is a keyword
     getargs(x, 0, 0, _("closed takes no arguments"))
-    return [r for r in subset if repo[r].extra().get('close')]
+    return [r for r in subset if repo[r].closesbranch()]
 
 def contains(repo, subset, x):
     """``contains(pattern)``