Shouldn't call finalize on LazyTraceThreadPoolTaskScheduler delegate; fixes gh-1485

.gitignore

@@ -23,3 +23,4 @@ jmh-result.csv
 pom.xml.versionsBackup
 .vscode
 .sts4-cache
+_includes

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/async/LazyTraceScheduledThreadPoolExecutor.java

@@ -365,7 +365,7 @@ class LazyTraceScheduledThreadPoolExecutor extends ScheduledThreadPoolExecutor {
 	@Override
 	@Deprecated
 	public void finalize() {
-		ReflectionUtils.invokeMethod(this.finalize, this.delegate);
+		super.finalize();
 	}
 
 	@Override

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/async/LazyTraceScheduledThreadPoolExecutorTests.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2013-2019 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
+ *
+ *      https://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.cloud.sleuth.instrument.async;
+
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.assertj.core.api.BDDAssertions;
+import org.junit.Test;
+import org.mockito.BDDMockito;
+
+import org.springframework.beans.factory.BeanFactory;
+
+public class LazyTraceScheduledThreadPoolExecutorTests {
+
+	@Test
+	public void should_not_finalize_the_delegate_since_its_a_shared_instance() {
+		AtomicBoolean wasCalled = new AtomicBoolean();
+		ScheduledThreadPoolExecutor executor = new ScheduledThreadPoolExecutor(10) {
+			@Override
+			protected void finalize() {
+				super.finalize();
+				wasCalled.set(true);
+			}
+		};
+		BeanFactory beanFactory = BDDMockito.mock(BeanFactory.class);
+
+		new LazyTraceScheduledThreadPoolExecutor(10, beanFactory, executor).finalize();
+
+		BDDAssertions.then(wasCalled).isFalse();
+	}
+
+}