diff -r 222fb8a512eb -r a5917346c72e mercurial/localrepo.py
--- a/mercurial/localrepo.py	Fri Jan 13 01:19:08 2012 +0100
+++ b/mercurial/localrepo.py	Fri Jan 13 02:29:38 2012 +0100
@@ -1263,9 +1263,7 @@
                 # if minimal phase was 0 we don't need to retract anything
                 phases.retractboundary(self, targetphase, [n])
             tr.close()
-
-            if self._branchcache:
-                self.updatebranchcache()
+            self.updatebranchcache()
             return n
         finally:
             if tr: