Fix bug where movie was failing to go into finished mode and would crash instead, fixes issue #429

BizHawk.Client.Common/movie/MovieSession.cs

@@ -136,9 +136,16 @@ namespace BizHawk.Client.Common
 		{
 			var input = Movie.GetInputState(Global.Emulator.Frame);
 
+			// adelikat: TODO: this is likely the source of frame 0 TAStudio bugs, I think the intent is to check if the movie is 0 length?
 			if (Global.Emulator.Frame == 0) // Hacky
 				HandleMovieAfterFrameLoop(); // Frame 0 needs to be handled.
 
+			if (input == null)
+			{
+				HandleMovieAfterFrameLoop();
+				return;
+			}
+
 			MovieControllerAdapter.LatchFromSource(input);
 			if (MultiTrack.IsActive)
 			{