Invalidate waveform on track load

osu.Game/Beatmaps/WorkingBeatmap.cs

@@ -105,7 +105,14 @@ public void CancelAsyncLoad()
 
         public virtual bool TrackLoaded => track != null;
 
-        public Track LoadTrack() => track = GetBeatmapTrack() ?? GetVirtualTrack(1000);
+        public Track LoadTrack()
+        {
+            // track could be changed, clearing waveform cache
+            waveform = null;
+
+            track = GetBeatmapTrack() ?? GetVirtualTrack(1000);
+            return track;
+        }
 
         public void PrepareTrackForPreview(bool looping, double offsetFromPreviewPoint = 0)
         {
@@ -172,12 +179,6 @@ protected Track GetVirtualTrack(double emptyLength = 0)
 
         public Waveform Waveform => waveform ??= GetWaveform();
 
-        /// <summary>
-        /// Reloads waveform of beatmap's track even if one is already cached.
-        /// </summary>
-        /// <returns>Newly loaded waveform.</returns>
-        public Waveform LoadWaveform() => waveform = GetWaveform();
-
         #endregion
 
         #region Beatmap

osu.Game/Screens/Edit/Setup/ResourcesSection.cs

@@ -118,7 +118,7 @@ public bool ChangeAudioTrack(FileInfo source)
             }
 
             working.Value.Metadata.AudioFile = destination.Name;
-            working.Value.LoadWaveform();
+
             editorBeatmap.SaveState();
             music.ReloadCurrentTrack();