From ac02bb005d982603c55002d8212af592453a584d Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Fri, 1 Nov 2019 14:11:18 +0900
Subject: [PATCH] Fix GameplayClockContainer operating on beatmap's track after
 scren exited

---
 osu.Game/Screens/Play/GameplayClockContainer.cs | 15 ++++++++++++++-
 osu.Game/Screens/Play/Player.cs                 |  4 ++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/osu.Game/Screens/Play/GameplayClockContainer.cs b/osu.Game/Screens/Play/GameplayClockContainer.cs
index 6a03271b86..f2efbe6073 100644
--- a/osu.Game/Screens/Play/GameplayClockContainer.cs
+++ b/osu.Game/Screens/Play/GameplayClockContainer.cs
@@ -8,6 +8,7 @@ using System.Threading.Tasks;
 using osu.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Audio;
+using osu.Framework.Audio.Track;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -29,7 +30,7 @@ namespace osu.Game.Screens.Play
         /// <summary>
         /// The original source (usually a <see cref="WorkingBeatmap"/>'s track).
         /// </summary>
-        private readonly IAdjustableClock sourceClock;
+        private IAdjustableClock sourceClock;
 
         public readonly BindableBool IsPaused = new BindableBool();
 
@@ -153,6 +154,18 @@ namespace osu.Game.Screens.Play
             IsPaused.Value = true;
         }
 
+        /// <summary>
+        /// Changes the backing clock to avoid using the originally provided beatmap's track.
+        /// </summary>
+        public void StopUsingBeatmapClock()
+        {
+            if (sourceClock != beatmap.Track)
+                return;
+
+            sourceClock = new TrackVirtual(beatmap.Track.Length);
+            adjustableClock.ChangeSource(sourceClock);
+        }
+
         public void ResetLocalAdjustments()
         {
             // In the case of replays, we may have changed the playback rate.
diff --git a/osu.Game/Screens/Play/Player.cs b/osu.Game/Screens/Play/Player.cs
index 0b363eac4d..4820c62da3 100644
--- a/osu.Game/Screens/Play/Player.cs
+++ b/osu.Game/Screens/Play/Player.cs
@@ -527,6 +527,10 @@ namespace osu.Game.Screens.Play
 
             GameplayClockContainer.ResetLocalAdjustments();
 
+            // GameplayClockContainer performs seeks / start / stop operations on the beatmap's track.
+            // as we are no longer the current screen, we cannot guarantee the track is still usable.
+            GameplayClockContainer.StopUsingBeatmapClock();
+
             fadeOut();
             return base.OnExiting(next);
         }