From 7c56e5307658eca580aee4540f28a41b9f8a011f Mon Sep 17 00:00:00 2001
From: Trask Stalnaker <trask.stalnaker@gmail.com>
Date: Fri, 2 Aug 2024 09:38:41 -0700
Subject: [PATCH] Fix sporadic test failure

---
 .../fakeingestion/MockedAppInsightsIngestionServlet.java      | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/smoke-tests/framework/src/main/java/com/microsoft/applicationinsights/smoketest/fakeingestion/MockedAppInsightsIngestionServlet.java b/smoke-tests/framework/src/main/java/com/microsoft/applicationinsights/smoketest/fakeingestion/MockedAppInsightsIngestionServlet.java
index 6fdbb3d6a0b..565365ab4d9 100644
--- a/smoke-tests/framework/src/main/java/com/microsoft/applicationinsights/smoketest/fakeingestion/MockedAppInsightsIngestionServlet.java
+++ b/smoke-tests/framework/src/main/java/com/microsoft/applicationinsights/smoketest/fakeingestion/MockedAppInsightsIngestionServlet.java
@@ -65,7 +65,9 @@ int getItemCount() {
   List<Envelope> getItemsByType(String type) {
     Objects.requireNonNull(type, "type");
     synchronized (multimapLock) {
-      return type2envelope.get(type);
+      // need to make a copy to avoid ConcurrentModificationException
+      // if the caller iterates over it at the same time as another telemetry item arrives
+      return new ArrayList<>(type2envelope.get(type));
     }
   }