From 4519bc00e78f3a8b08b22e7d33381f29acca846a Mon Sep 17 00:00:00 2001
From: Chris Riley <36002394+bdchris@users.noreply.github.com>
Date: Wed, 7 Apr 2021 14:49:35 -0500
Subject: [PATCH] Check _cleanupTimer is not null when disposing

Backporting fix for #4818
This commit checks that _cleanupTimer is not null when disposing, which it may be if no requests have been made.

Fixes #5529
---
 .../Connection/HandlerTracking/RequestDataHttpClientFactory.cs  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Elasticsearch.Net/Connection/HandlerTracking/RequestDataHttpClientFactory.cs b/src/Elasticsearch.Net/Connection/HandlerTracking/RequestDataHttpClientFactory.cs
index 1629cf80fc8..2fe809bff6e 100644
--- a/src/Elasticsearch.Net/Connection/HandlerTracking/RequestDataHttpClientFactory.cs
+++ b/src/Elasticsearch.Net/Connection/HandlerTracking/RequestDataHttpClientFactory.cs
@@ -154,7 +154,7 @@ protected virtual void StopCleanupTimer()
 		{
 			lock (_cleanupTimerLock)
 			{
-				_cleanupTimer.Dispose();
+				_cleanupTimer?.Dispose();
 				_cleanupTimer = null;
 			}
 		}