diff -r 698b615a1cde -r 5ee250974db9 src/share/vm/runtime/synchronizer.cpp
--- a/src/share/vm/runtime/synchronizer.cpp	Wed Feb 27 16:40:30 2013 +0000
+++ b/src/share/vm/runtime/synchronizer.cpp	Wed Feb 27 15:00:30 2013 -0800
@@ -813,6 +813,7 @@
   }
 
   if (owner != NULL) {
+    // owning_thread_from_monitor_owner() may also return NULL here
     return Threads::owning_thread_from_monitor_owner(owner, doLock);
   }