From b3a25fb9e8badf9d243db4935edbd09bebf0dee9 Mon Sep 17 00:00:00 2001
From: Christian <christian.kratky@googlemail.com>
Date: Mon, 5 Mar 2018 20:43:37 +0100
Subject: [PATCH] Fix subscription handling of _ManagedClient_.

---
 .../ManagedClient/ManagedMqttClient.cs           | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/Frameworks/MQTTnet.NetStandard/ManagedClient/ManagedMqttClient.cs b/Frameworks/MQTTnet.NetStandard/ManagedClient/ManagedMqttClient.cs
index 5a392c30..ffb86394 100644
--- a/Frameworks/MQTTnet.NetStandard/ManagedClient/ManagedMqttClient.cs
+++ b/Frameworks/MQTTnet.NetStandard/ManagedClient/ManagedMqttClient.cs
@@ -45,6 +45,7 @@ namespace MQTTnet.ManagedClient
         public event EventHandler<MqttClientDisconnectedEventArgs> Disconnected;
         public event EventHandler<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceived;
         public event EventHandler<ApplicationMessageProcessedEventArgs> ApplicationMessageProcessed;
+        public event EventHandler SynchronizingSubscriptionsFailed;
 
         public async Task StartAsync(IManagedMqttClientOptions options)
         {
@@ -309,13 +310,22 @@ namespace MQTTnet.ManagedClient
 
             try
             {
-                await _mqttClient.SubscribeAsync(subscriptions).ConfigureAwait(false);
-                await _mqttClient.UnsubscribeAsync(unsubscriptions).ConfigureAwait(false);
+                if (subscriptions.Any())
+                {
+                    await _mqttClient.SubscribeAsync(subscriptions).ConfigureAwait(false);
+                }
+
+                if (unsubscriptions.Any())
+                {
+                    await _mqttClient.UnsubscribeAsync(unsubscriptions).ConfigureAwait(false);
+                }
             }
             catch (Exception exception)
             {
-                _logger.Warning<ManagedMqttClient>(exception, "Synchronizing subscriptions failed");
+                _logger.Warning<ManagedMqttClient>(exception, "Synchronizing subscriptions failed.");
                 _subscriptionsNotPushed = true;
+
+                SynchronizingSubscriptionsFailed?.Invoke(this, EventArgs.Empty);
             }
         }