Simplify movie stopping+saving logic, fixing bug where opening a new movie while in recording mode in TAStudio would save the current movie even if the user said not to. (#4341)

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

@@ -260,11 +260,12 @@ namespace BizHawk.Client.Common
 
 				message += "stopped.";
 
-				var result = Movie.Stop(saveChanges);
-				if (result)
+				if (saveChanges && Movie.Changes)
 				{
+					Movie.Save();
 					Output($"{Path.GetFileName(Movie.Filename)} written to disk.");
 				}
+				Movie.Stop();
 
 				Output(message);
 				ReadOnly = true;
@@ -372,7 +373,7 @@ namespace BizHawk.Client.Common
 			switch (Settings.MovieEndAction)
 			{
 				case MovieEndAction.Stop:
-					Movie.Stop();
+					StopMovie();
 					break;
 				case MovieEndAction.Record:
 					Movie.SwitchToRecord();

src/BizHawk.Client.Common/movie/bk2/Bk2Movie.ModeApi.cs

@@ -20,23 +20,6 @@
 		public void SwitchToRecord() => Mode = MovieMode.Record;
 		public void SwitchToPlay() => Mode = MovieMode.Play;
 		public void FinishedMode() => Mode = MovieMode.Finished;
-
-		public virtual bool Stop(bool saveChanges = true)
-		{
-			bool saved = false;
-			if (saveChanges)
-			{
-				if (Mode == MovieMode.Record || (this.IsActive() && Changes))
-				{
-					Save();
-					saved = true;
-				}
-			}
-
-			Changes = false;
-			Mode = MovieMode.Inactive;
-
-			return saved;
-		}
+		public void Stop() =>  Mode = MovieMode.Inactive;
 	}
 }

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

@@ -121,11 +121,8 @@ namespace BizHawk.Client.Common
 
 		/// <summary>
 		/// Sets the movie to inactive (note that it will still be in memory)
-		/// The saveChanges flag will tell the movie to save its contents to disk
 		/// </summary>
-		/// <param name="saveChanges">if true, will save to disk</param>
-		/// <returns>Whether or not the movie was saved</returns>
-		bool Stop(bool saveChanges = true);
+		void Stop();
 
 		/// <summary>
 		/// Switches to record mode