BridgeMethodResolver properly handles bridge methods in interfaces

Issue: SPR-9330

spring-core/src/main/java/org/springframework/core/BridgeMethodResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,7 +25,6 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
-import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ReflectionUtils;
 
@@ -145,7 +144,7 @@ public abstract class BridgeMethodResolver {
 	private static Method findGenericDeclaration(Method bridgeMethod) {
 		// Search parent types for method that has same signature as bridge.
 		Class superclass = bridgeMethod.getDeclaringClass().getSuperclass();
-		while (!Object.class.equals(superclass)) {
+		while (superclass != null && !Object.class.equals(superclass)) {
 			Method method = searchForMatch(superclass, bridgeMethod);
 			if (method != null && !method.isBridge()) {
 				return method;
@@ -219,8 +218,6 @@ public abstract class BridgeMethodResolver {
 	 * @return whether signatures match as described
 	 */
 	public static boolean isVisibilityBridgeMethodPair(Method bridgeMethod, Method bridgedMethod) {
-		Assert.isTrue(bridgeMethod != null);
-		Assert.isTrue(bridgedMethod != null);
 		if (bridgeMethod == bridgedMethod) {
 			return true;
 		}