Only use payload if it actually matches declared event type

Closes gh-22426

spring-context/src/test/java/org/springframework/context/event/PayloadApplicationEventTests.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2002-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.event;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.PayloadApplicationEvent;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.stereotype.Component;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Juergen Hoeller
+ */
+public class PayloadApplicationEventTests {
+
+	@Test
+	public void testEventClassWithInterface() {
+		ApplicationContext ac = new AnnotationConfigApplicationContext(Listener.class);
+		MyEventClass event = new MyEventClass<>(this, "xyz");
+		ac.publishEvent(event);
+		assertTrue(ac.getBean(Listener.class).events.contains(event));
+	}
+
+
+	public interface Auditable {
+	}
+
+
+	public static class MyEventClass<GT> extends PayloadApplicationEvent<GT> implements Auditable {
+
+		public MyEventClass(Object source, GT payload) {
+			super(source, payload);
+		}
+
+		public String toString() {
+			return "Payload: " + getPayload();
+		}
+	}
+
+
+	@Component
+	public static class Listener {
+
+		public final List<Auditable> events = new ArrayList<>();
+
+		@EventListener
+		public void onEvent(Auditable event) {
+			events.add(event);
+		}
+	}
+
+}