diff -r 9aebeea7ac00 -r bbc78cb1bf15 mercurial/localrepo.py
--- a/mercurial/localrepo.py	Sat Jul 04 14:18:15 2009 +0100
+++ b/mercurial/localrepo.py	Thu Jul 09 19:49:02 2009 -0500
@@ -473,7 +473,9 @@
                 latest = newnodes.pop()
                 if latest not in bheads:
                     continue
-                reachable = self.changelog.reachable(latest, bheads[0])
+                reachable = set()
+                for bh in bheads:
+                    reachable |= self.changelog.reachable(latest, bh)
                 bheads = [b for b in bheads if b not in reachable]
                 newbheads.insert(0, latest)
             bheads.extend(newbheads)