From b3e7d436e5c32dd29253e55970a7b9210bc34aa7 Mon Sep 17 00:00:00 2001
From: Nick Tindall <nick.tindall@elastic.co>
Date: Thu, 1 Aug 2024 11:04:01 +1000
Subject: [PATCH] Fix
 IndexFoldersDeletionListenerIT#testListenersInvokedWhenIndexIsDangling
 (#111440)

Closes #111192
---
 .../elasticsearch/plugins/IndexFoldersDeletionListenerIT.java   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/src/internalClusterTest/java/org/elasticsearch/plugins/IndexFoldersDeletionListenerIT.java b/server/src/internalClusterTest/java/org/elasticsearch/plugins/IndexFoldersDeletionListenerIT.java
index 542a4cd2c4c92..db26d630fefea 100644
--- a/server/src/internalClusterTest/java/org/elasticsearch/plugins/IndexFoldersDeletionListenerIT.java
+++ b/server/src/internalClusterTest/java/org/elasticsearch/plugins/IndexFoldersDeletionListenerIT.java
@@ -350,7 +350,7 @@ public void beforeIndexFoldersDeleted(Index index, IndexSettings indexSettings,
 
                 @Override
                 public void beforeShardFoldersDeleted(ShardId shardId, IndexSettings indexSettings, Path[] shardPaths) {
-                    deletedShards.computeIfAbsent(shardId.getIndex(), i -> new ArrayList<>()).add(shardId);
+                    deletedShards.computeIfAbsent(shardId.getIndex(), i -> Collections.synchronizedList(new ArrayList<>())).add(shardId);
                 }
             });
         }