Index: vm/vmcore/src/kernel_classes/javasrc/java/lang/Runtime.java =================================================================== --- vm/vmcore/src/kernel_classes/javasrc/java/lang/Runtime.java (revision 429290) +++ vm/vmcore/src/kernel_classes/javasrc/java/lang/Runtime.java (working copy) @@ -146,6 +146,10 @@ */ static void addShutdownHook(Thread hook) throws IllegalStateException, IllegalArgumentException { + // Check hook for null + if (hook == null) + throw new NullPointerException("null is not allowed here"); + synchronized (hooksList) { if (hooksList.contains((Object) hook)) { throw new IllegalArgumentException(); @@ -168,6 +172,10 @@ */ static boolean removeShutdownHook(Thread hook) throws IllegalStateException { + // Check hook for null + if (hook == null) + throw new NullPointerException("null is not allowed here"); + synchronized (Synchro.class) { if (VMState > 0) { throw new IllegalStateException();