From bec9966e30fa6732f1dc72699dc05d526c17803b Mon Sep 17 00:00:00 2001
From: Trask Stalnaker <trask.stalnaker@gmail.com>
Date: Sat, 12 Jun 2021 01:37:04 -0700
Subject: [PATCH] Fix failing test (#3269)

---
 examples/distro/gradle/instrumentation.gradle                 | 2 ++
 .../opentelemetry/javaagent/tooling/ExtensionClassLoader.java | 4 ++++
 javaagent/javaagent.gradle                                    | 2 ++
 testing/agent-for-testing/agent-for-testing.gradle            | 2 ++
 4 files changed, 10 insertions(+)

diff --git a/examples/distro/gradle/instrumentation.gradle b/examples/distro/gradle/instrumentation.gradle
index a5b7e072a4..b241ec8eba 100644
--- a/examples/distro/gradle/instrumentation.gradle
+++ b/examples/distro/gradle/instrumentation.gradle
@@ -38,6 +38,8 @@ shadowJar {
 }
 
 tasks.withType(Test).configureEach {
+  inputs.file(shadowJar.archiveFile)
+
   jvmArgs "-Dotel.javaagent.debug=true"
   jvmArgs "-javaagent:${configurations.testAgent.files.first().absolutePath}"
   jvmArgs "-Dotel.javaagent.experimental.initializer.jar=${shadowJar.archiveFile.get().asFile.absolutePath}"
diff --git a/javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/ExtensionClassLoader.java b/javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/ExtensionClassLoader.java
index f308139f9b..6d27d37cba 100644
--- a/javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/ExtensionClassLoader.java
+++ b/javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/ExtensionClassLoader.java
@@ -44,6 +44,10 @@ public class ExtensionClassLoader extends URLClassLoader {
                 System.getenv("OTEL_JAVAAGENT_EXPERIMENTAL_INITIALIZER_JAR"))));
     // TODO when logging is configured add warning about deprecated property
 
+    if (extension.isEmpty()) {
+      return parent;
+    }
+
     List<ClassLoader> delegates = new ArrayList<>(extension.size());
     for (URL url : extension) {
       delegates.add(getDelegate(parent, url));
diff --git a/javaagent/javaagent.gradle b/javaagent/javaagent.gradle
index 5e115a1621..7a6e0e9d4b 100644
--- a/javaagent/javaagent.gradle
+++ b/javaagent/javaagent.gradle
@@ -133,6 +133,8 @@ dependencies {
 }
 
 tasks.withType(Test).configureEach {
+  inputs.file(shadowJar.archiveFile)
+
   jvmArgs "-Dotel.javaagent.debug=true"
 
   doFirst {
diff --git a/testing/agent-for-testing/agent-for-testing.gradle b/testing/agent-for-testing/agent-for-testing.gradle
index ad78b91a91..571d99f661 100644
--- a/testing/agent-for-testing/agent-for-testing.gradle
+++ b/testing/agent-for-testing/agent-for-testing.gradle
@@ -88,6 +88,8 @@ dependencies {
 
 afterEvaluate {
   tasks.withType(Test).configureEach {
+    inputs.file(shadowJar.archiveFile)
+
     jvmArgs "-Dotel.javaagent.debug=true"
     jvmArgs "-javaagent:${shadowJar.archiveFile.get().asFile.absolutePath}"