From 016e3957879af6012d0a82cea655ce0eed2f9ae8 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Thu, 6 Sep 2018 17:11:23 +0900
Subject: [PATCH] Fix disposal logic

---
 osu.Game/Overlays/ChatOverlay.cs | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/osu.Game/Overlays/ChatOverlay.cs b/osu.Game/Overlays/ChatOverlay.cs
index 47262068d1..912734ba0c 100644
--- a/osu.Game/Overlays/ChatOverlay.cs
+++ b/osu.Game/Overlays/ChatOverlay.cs
@@ -354,9 +354,13 @@ namespace osu.Game.Overlays
         protected override void Dispose(bool isDisposing)
         {
             base.Dispose(isDisposing);
-            channelManager.CurrentChannel.ValueChanged -= currentChannelChanged;
-            channelManager.JoinedChannels.CollectionChanged -= joinedChannelsChanged;
-            channelManager.AvailableChannels.CollectionChanged -= availableChannelsChanged;
+
+            if (channelManager != null)
+            {
+                channelManager.CurrentChannel.ValueChanged -= currentChannelChanged;
+                channelManager.JoinedChannels.CollectionChanged -= joinedChannelsChanged;
+                channelManager.AvailableChannels.CollectionChanged -= availableChannelsChanged;
+            }
         }
 
         private void postMessage(TextBox textbox, bool newText)