From f9923c2f16e4a64547df8b745aa664e16df2e252 Mon Sep 17 00:00:00 2001
From: Shreyas Zare <shreyas@technitium.com>
Date: Sat, 6 Nov 2021 13:35:42 +0530
Subject: [PATCH] Failover.HealthMonitor: fixed LastHealthCheckResponse
 property to not return null values.

---
 Apps/FailoverApp/HealthMonitor.cs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Apps/FailoverApp/HealthMonitor.cs b/Apps/FailoverApp/HealthMonitor.cs
index 3b693907..d17fd4c3 100644
--- a/Apps/FailoverApp/HealthMonitor.cs
+++ b/Apps/FailoverApp/HealthMonitor.cs
@@ -21,7 +21,7 @@ using DnsServerCore.ApplicationCommon;
 using System;
 using System.Net;
 using System.Threading;
-using TechnitiumLibrary.Net.Dns;
+using TechnitiumLibrary.Net.Dns.ResourceRecords;
 
 namespace Failover
 {
@@ -310,6 +310,10 @@ namespace Failover
             get
             {
                 _lastHealthStatusCheckedOn = DateTime.UtcNow;
+
+                if (_lastHealthCheckResponse is null)
+                    return new HealthCheckResponse(HealthStatus.Unknown);
+
                 return _lastHealthCheckResponse;
             }
         }