From a849bc074654a65d25500f14ade4cff330683ce0 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Fri, 8 Nov 2019 18:51:01 +0900
Subject: [PATCH] Move implementation into resetTrack for safety

---
 osu.Game/Screens/Edit/Editor.cs | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/osu.Game/Screens/Edit/Editor.cs b/osu.Game/Screens/Edit/Editor.cs
index f932517387..ca3b4fdce5 100644
--- a/osu.Game/Screens/Edit/Editor.cs
+++ b/osu.Game/Screens/Edit/Editor.cs
@@ -69,14 +69,6 @@ namespace osu.Game.Screens.Edit
             clock = new EditorClock(Beatmap.Value, beatDivisor) { IsCoupled = false };
             clock.ChangeSource(sourceClock);
 
-            if (Beatmap.Value.Beatmap.HitObjects.Count > 0)
-            {
-                double targetTime = Beatmap.Value.Beatmap.HitObjects[0].StartTime;
-                double beatLength = Beatmap.Value.Beatmap.ControlPointInfo.TimingPointAt(targetTime).BeatLength;
-
-                clock.Seek(Math.Max(0, targetTime - beatLength));
-            }
-
             dependencies.CacheAs<IFrameBasedClock>(clock);
             dependencies.CacheAs<IAdjustableClock>(clock);
             dependencies.Cache(beatDivisor);
@@ -249,7 +241,8 @@ namespace osu.Game.Screens.Edit
             base.OnEntering(last);
 
             Background.FadeColour(Color4.DarkGray, 500);
-            resetTrack();
+
+            resetTrack(true);
         }
 
         public override bool OnExiting(IScreen next)
@@ -260,10 +253,24 @@ namespace osu.Game.Screens.Edit
             return base.OnExiting(next);
         }
 
-        private void resetTrack()
+        private void resetTrack(bool seekToStart = false)
         {
             Beatmap.Value.Track?.ResetSpeedAdjustments();
             Beatmap.Value.Track?.Stop();
+
+            if (seekToStart)
+            {
+                double targetTime = 0;
+
+                if (Beatmap.Value.Beatmap.HitObjects.Count > 0)
+                {
+                    // seek to one beat length before the first hitobject
+                    targetTime = Beatmap.Value.Beatmap.HitObjects[0].StartTime;
+                    targetTime -= Beatmap.Value.Beatmap.ControlPointInfo.TimingPointAt(targetTime).BeatLength;
+                }
+
+                clock.Seek(Math.Max(0, targetTime));
+            }
         }
 
         private void exportBeatmap() => host.OpenFileExternally(Beatmap.Value.Save());