tests and fix for pr119352

aspectj5rt/java5-src/org/aspectj/internal/lang/reflect/AjTypeImpl.java

@@ -120,7 +120,7 @@ public class AjTypeImpl<T> implements AjType<T> {
 	 */
 	public AjType<? super T> getSupertype() {
 		Class<? super T> superclass = clazz.getSuperclass();
-		return (AjType<? super T>) new AjTypeImpl(superclass);
+		return superclass==null ? null : (AjType<? super T>) new AjTypeImpl(superclass);
 	}
 
 	/* (non-Javadoc)

aspectj5rt/java5-testsrc/org/aspectj/internal/lang/reflect/AjTypeTests.java

@@ -62,9 +62,19 @@ public class AjTypeTests extends TestCase {
 	public void testGetSupertype() {
 		Class<?> stringSuper = String.class.getSuperclass();
 		AjType ajSuper = stringType.getSupertype();
-		assertEquals(AjTypeSystem.getAjType(stringSuper),ajSuper);
+		assertEquals(AjTypeSystem.getAjType(stringSuper),ajSuper);		
 	}
 
+	public void testObjectSupertype() {
+		AjType<?> objectSuper = AjTypeSystem.getAjType(Object.class).getSupertype();
+		assertNull(objectSuper);		
+	}
+
+	public void testInterfaceSupertype() {
+		AjType<?> serializableSuper = AjTypeSystem.getAjType(Serializable.class).getSupertype();
+		assertNull(serializableSuper);		
+	}
+	
 	public void testGetGenericSupertype() {
 		Type t  = AjTypeSystem.getAjType(Goo.class).getGenericSupertype();
 		assertEquals(Foo.class,t);