dispose of TasStateManager

src/BizHawk.Client.Common/movie/MovieSession.cs

@@ -277,6 +277,11 @@ namespace BizHawk.Client.Common
 				_modeChangedCallback();
 			}
 
+			if (Movie is IDisposable d)
+			{
+				d.Dispose();
+			}
+
 			Movie = null;
 		}
 

src/BizHawk.Client.Common/movie/interfaces/ITasMovie.cs

@@ -6,7 +6,7 @@ using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.Common
 {
-	public interface ITasMovie : IMovie, INotifyPropertyChanged
+	public interface ITasMovie : IMovie, INotifyPropertyChanged, IDisposable
 	{
 		bool BindMarkersToInput { get; set; }
 		bool LastPositionStable { get; set; }

src/BizHawk.Client.Common/movie/tasproj/IStateManager.cs

@@ -1,10 +1,11 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.IO;
 using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.Common
 {
-	public interface IStateManager
+	public interface IStateManager : IDisposable
 	{
 		/// <summary>
 		/// Retrieves the savestate for the given frame,

src/BizHawk.Client.Common/movie/tasproj/TasMovie.cs

@@ -350,5 +350,11 @@ namespace BizHawk.Client.Common
 			return Markers.Any(m => m.Frame - 1 == frame)
 				|| Branches.Any(b => b.Frame == frame); // Branches should already be in the reserved list, but it doesn't hurt to check
 		}
+
+		public void Dispose()
+		{
+			TasStateManager?.Dispose();
+			TasStateManager = null;
+		}
 	}
 }