diff -r 590ac023c536 -r f597421662f7 hgext/evolve.py
--- a/hgext/evolve.py	Thu Jun 21 19:24:19 2012 +0200
+++ b/hgext/evolve.py	Thu Jun 21 19:58:57 2012 +0200
@@ -142,10 +142,8 @@
                 bookmarks.write(repo)
 
             # add evolution metadata
-            repo.addobsolete(new.node(), old.node())
-            for u in updates:
-                repo.addobsolete(u.node(), old.node())
-                repo.addobsolete(new.node(), u.node())
+            collapsed = set([u.node() for u in updates] + [old.node()])
+            repo.addcollapsedobsolete(collapsed, new.node())
             oldbookmarks = repo.nodebookmarks(old.node())
             for book in oldbookmarks:
                 repo._bookmarks[book] = new.node()