--- a/mercurial/localrepo.py	Mon Sep 08 20:57:44 2014 +0200
+++ b/mercurial/localrepo.py	Fri Sep 05 11:34:29 2014 -0700
@@ -1102,7 +1102,11 @@
             return l
 
         def unlock():
-            self.dirstate.write()
+            if self.dirstate.pendingparentchange():
+                self.dirstate.invalidate()
+            else:
+                self.dirstate.write()
+
             self._filecache['dirstate'].refresh()
 
         l = self._lock(self.vfs, "wlock", wait, unlock,