From eedfbdc0e8de2f3da4418a20ac42e1b84ee16404 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Mon, 11 Sep 2017 11:41:09 +0900
Subject: [PATCH] Add nullref check in KeyCounterCollection's Add method

---
 osu.Game/Screens/Play/KeyCounterCollection.cs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/osu.Game/Screens/Play/KeyCounterCollection.cs b/osu.Game/Screens/Play/KeyCounterCollection.cs
index 0f6c5984c4..d21be71785 100644
--- a/osu.Game/Screens/Play/KeyCounterCollection.cs
+++ b/osu.Game/Screens/Play/KeyCounterCollection.cs
@@ -28,6 +28,8 @@ namespace osu.Game.Screens.Play
 
         public override void Add(KeyCounter key)
         {
+            if (key == null) throw new ArgumentNullException(nameof(key));
+
             base.Add(key);
             key.IsCounting = IsCounting;
             key.FadeTime = FadeTime;