Change loadstate methods to return a bool indicating success

src/BizHawk.Client.Common/Api/Classes/EmuClientApi.cs

@@ -103,7 +103,11 @@ namespace BizHawk.Client.Common
 
 		public bool IsTurbo() => _mainForm.IsTurboing;
 
-		public void LoadState(string name) => _mainForm.LoadState(Path.Combine(_config.PathEntries.SaveStateAbsolutePath(Game.System), $"{name}.State"), name, suppressOSD: false);
+		public bool LoadState(string name)
+			=> _mainForm.LoadState(
+				path: Path.Combine(_config.PathEntries.SaveStateAbsolutePath(Game.System), $"{name}.State"),
+				userFriendlyStateName: name,
+				suppressOSD: false);
 
 		public void OnBeforeQuickLoad(object sender, string quickSaveSlotName, out bool eventHandled)
 		{

src/BizHawk.Client.Common/Api/Classes/SaveStateApi.cs

@@ -19,18 +19,17 @@ namespace BizHawk.Client.Common
 			_mainForm = mainForm;
 		}
 
-		public void Load(string path, bool suppressOSD)
+		public bool Load(string path, bool suppressOSD)
 		{
 			if (!File.Exists(path))
 			{
 				LogCallback($"could not find file: {path}");
-				return;
+				return false;
 			}
-
-			_mainForm.LoadState(path, Path.GetFileName(path), suppressOSD);
+			return _mainForm.LoadState(path: path, userFriendlyStateName: Path.GetFileName(path), suppressOSD);
 		}
 
-		public void LoadSlot(int slotNum, bool suppressOSD)
+		public bool LoadSlot(int slotNum, bool suppressOSD)
 		{
 			if (slotNum is < 0 or > 10) throw new ArgumentOutOfRangeException(paramName: nameof(slotNum), message: ERR_MSG_NOT_A_SLOT);
 			if (slotNum is 0)
@@ -38,7 +37,7 @@ namespace BizHawk.Client.Common
 				LogCallback(ERR_MSG_USE_SLOT_10);
 				slotNum = 10;
 			}
-			_mainForm.LoadQuickSave(slotNum, suppressOSD: suppressOSD);
+			return _mainForm.LoadQuickSave(slotNum, suppressOSD: suppressOSD);
 		}
 
 		public void Save(string path, bool suppressOSD) => _mainForm.SaveState(path, path, true, suppressOSD);

src/BizHawk.Client.Common/Api/Interfaces/IEmuClientApi.cs

@@ -88,7 +88,7 @@ namespace BizHawk.Client.Common
 		/// Load a savestate specified by its name
 		/// </summary>
 		/// <param name="name">Savestate friendly name</param>
-		void LoadState(string name);
+		bool LoadState(string name);
 
 		/// <summary>
 		/// Raised before a quickload is done (just after pressing shortcut button)

src/BizHawk.Client.Common/Api/Interfaces/ISaveStateApi.cs

@@ -2,8 +2,10 @@
 {
 	public interface ISaveStateApi : IExternalApi
 	{
-		void Load(string path, bool suppressOSD = false);
-		void LoadSlot(int slotNum, bool suppressOSD = false);
+		bool Load(string path, bool suppressOSD = false);
+
+		bool LoadSlot(int slotNum, bool suppressOSD = false);
+
 		void Save(string path, bool suppressOSD = false);
 		void SaveSlot(int slotNum, bool suppressOSD = false);
 	}

src/BizHawk.Client.Common/IMainFormForApi.cs

@@ -69,12 +69,12 @@ namespace BizHawk.Client.Common
 		bool LoadMovie(string filename, string archive = null);
 
 		/// <remarks>only referenced from <see cref="SaveStateApi"/></remarks>
-		void LoadQuickSave(int slot, bool suppressOSD = false);
+		bool LoadQuickSave(int slot, bool suppressOSD = false);
 
 		/// <remarks>only referenced from <c>EmuClientApi</c></remarks>
 		bool LoadRom(string path, LoadRomArgs args);
 
-		void LoadState(string combine, string name, bool suppressOSD = false);
+		bool LoadState(string path, string userFriendlyStateName, bool suppressOSD = false);
 
 		/// <remarks>only referenced from <c>EmuClientApi</c></remarks>
 		void PauseEmulator();

src/BizHawk.Client.Common/lua/CommonLibs/SaveStateLuaLibrary.cs

@@ -11,24 +11,22 @@ namespace BizHawk.Client.Common
 
 		[LuaMethodExample("savestate.load( \"C:\\state.bin\" );")]
 		[LuaMethod("load", "Loads a savestate with the given path. If EmuHawk is deferring quicksaves, to TAStudio for example, that form will do what it likes (and the path is ignored).")]
-		public void Load(string path, bool suppressOSD = false)
+		public bool Load(string path, bool suppressOSD = false)
 		{
 			_luaLibsImpl.IsUpdateSupressed = true;
-
-			APIs.SaveState.Load(path, suppressOSD);
-			
+			var success = APIs.SaveState.Load(path, suppressOSD);
 			_luaLibsImpl.IsUpdateSupressed = false;
+			return success;
 		}
 
 		[LuaMethodExample("savestate.loadslot( 7 );")]
 		[LuaMethod("loadslot", "Loads the savestate at the given slot number (must be an integer between 0 and 9). If EmuHawk is deferring quicksaves, to TAStudio for example, that form will do what it likes with the slot number.")]
-		public void LoadSlot(int slotNum, bool suppressOSD = false)
+		public bool LoadSlot(int slotNum, bool suppressOSD = false)
 		{
 			_luaLibsImpl.IsUpdateSupressed = true;
-
-			APIs.SaveState.LoadSlot(slotNum, suppressOSD);
-			
+			var success = APIs.SaveState.LoadSlot(slotNum, suppressOSD: suppressOSD);
 			_luaLibsImpl.IsUpdateSupressed = false;
+			return success;
 		}
 
 		[LuaMethodExample("savestate.save( \"C:\\state.bin\" );")]

src/BizHawk.Client.EmuHawk/IControlMainform.cs

@@ -8,11 +8,16 @@
 		bool WantsToControlSavestates { get; }
 
 		void SaveState();
-		void LoadState();
+
+		bool LoadState();
+
 		void SaveStateAs();
-		void LoadStateAs();
+
+		bool LoadStateAs();
+
 		void SaveQuickSave(int slot);
-		void LoadQuickSave(int slot);
+
+		bool LoadQuickSave(int slot);
 
 		/// <summary>
 		/// Overrides the select slot method

src/BizHawk.Client.EmuHawk/IMainFormForTools.cs

@@ -65,7 +65,7 @@ namespace BizHawk.Client.EmuHawk
 		void FrameBufferResized();
 
 		/// <remarks>only referenced from <see cref="BasicBot"/></remarks>
-		void LoadQuickSave(int slot, bool suppressOSD = false);
+		bool LoadQuickSave(int slot, bool suppressOSD = false);
 
 		/// <remarks>only referenced from <see cref="MultiDiskBundler"/></remarks>
 		bool LoadRom(string path, LoadRomArgs args);

src/BizHawk.Client.EmuHawk/MainForm.Events.cs

@@ -406,7 +406,7 @@ namespace BizHawk.Client.EmuHawk
 		private void LoadCurrentSlotMenuItem_Click(object sender, EventArgs e)
 			=> LoadstateCurrentSlot();
 
-		private void LoadstateCurrentSlot()
+		private bool LoadstateCurrentSlot()
 			=> LoadQuickSave(Config.SaveSlot);
 
 		private void FlushSaveRAMMenuItem_Click(object sender, EventArgs e)
@@ -2522,7 +2522,7 @@ namespace BizHawk.Client.EmuHawk
 			if (sender == Slot0StatusButton) slot = 10;
 
 			if (e.Button is MouseButtons.Right) SaveQuickSave(slot);
-			else if (e.Button is MouseButtons.Left && HasSlot(slot)) LoadQuickSave(slot);
+			else if (e.Button is MouseButtons.Left && HasSlot(slot)) _ = LoadQuickSave(slot);
 		}
 
 		private void KeyPriorityStatusLabel_Click(object sender, EventArgs e)

src/BizHawk.Client.EmuHawk/MainForm.FileLoader.cs

@@ -108,10 +108,8 @@ namespace BizHawk.Client.EmuHawk
 			LoadRom(filename, args);
 		}
 
-		private void LoadStateFile(string filename, string archive = null)
-		{
-			LoadState(filename, Path.GetFileName(filename));
-		}
+		private bool LoadStateFile(string filename, string archive = null)
+			=> LoadState(path: filename, userFriendlyStateName: Path.GetFileName(filename));
 
 		private void LoadWatch(string filename, string archive = null)
 		{
@@ -267,7 +265,7 @@ namespace BizHawk.Client.EmuHawk
 								LoadRom(filename, fileInformation.ArchiveName);
 								break;
 							case LoadOrdering.State:
-								LoadStateFile(filename, fileInformation.ArchiveName);
+								_ = LoadStateFile(filename, fileInformation.ArchiveName);
 								break;
 							case LoadOrdering.Watch:
 								LoadWatch(filename, fileInformation.ArchiveName);

src/BizHawk.Client.EmuHawk/MainForm.Hotkey.cs

@@ -18,7 +18,7 @@ namespace BizHawk.Client.EmuHawk
 			}
 			void SelectAndLoadFromSlot(int slot)
 			{
-				LoadQuickSave(slot);
+				_ = LoadQuickSave(slot);
 				Config.SaveSlot = slot;
 				UpdateStatusSlots();
 			}
@@ -63,7 +63,7 @@ namespace BizHawk.Client.EmuHawk
 					HardReset();
 					break;
 				case "Quick Load":
-					LoadstateCurrentSlot();
+					_ = LoadstateCurrentSlot();
 					break;
 				case "Quick Save":
 					SavestateCurrentSlot();
@@ -255,7 +255,7 @@ namespace BizHawk.Client.EmuHawk
 					SaveStateAs();
 					break;
 				case "Load Named State":
-					LoadStateAs();
+					_ = LoadStateAs();
 					break;
 				case "Previous Slot":
 					PreviousSlot();

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -658,15 +658,17 @@ namespace BizHawk.Client.EmuHawk
 			{
 				if (_argParser.cmdLoadState != null)
 				{
-					LoadState(_argParser.cmdLoadState, Path.GetFileName(_argParser.cmdLoadState));
+					_ = LoadState(
+						path: _argParser.cmdLoadState,
+						userFriendlyStateName: Path.GetFileName(_argParser.cmdLoadState));
 				}
 				else if (_argParser.cmdLoadSlot != null)
 				{
-					LoadQuickSave(_argParser.cmdLoadSlot.Value);
+					_ = LoadQuickSave(_argParser.cmdLoadSlot.Value);
 				}
 				else if (Config.AutoLoadLastSaveSlot)
 				{
-					LoadstateCurrentSlot();
+					_ = LoadstateCurrentSlot();
 				}
 			}
 
@@ -3958,7 +3960,7 @@ namespace BizHawk.Client.EmuHawk
 					Tools.UpdateCheatRelatedTools(null, null);
 					if (!MovieSession.NewMovieQueued && Config.AutoLoadLastSaveSlot && HasSlot(Config.SaveSlot))
 					{
-						LoadstateCurrentSlot();
+						_ = LoadstateCurrentSlot();
 					}
 
 					if (FirmwareManager.RecentlyServed.Count > 0)
@@ -4201,23 +4203,15 @@ namespace BizHawk.Client.EmuHawk
 			return int.Parse(slot.Substring(slot.Length - 1, 1));
 		}
 
-		public void LoadState(string path, string userFriendlyStateName, bool suppressOSD = false) // Move to client.common
+		public bool LoadState(string path, string userFriendlyStateName, bool suppressOSD = false) // Move to client.common
 		{
-			if (!Emulator.HasSavestates())
-			{
-				return;
-			}
-
-			if (IsSavestateSlave)
-			{
-				Master.LoadState();
-				return;
-			}
+			if (!Emulator.HasSavestates()) return false;
+			if (IsSavestateSlave) return Master.LoadState();
 
 			if (!new SavestateFile(Emulator, MovieSession, QuickBmpFile, MovieSession.UserBag).Load(path, this))
 			{
 				AddOnScreenMessage("Loadstate error!");
-				return;
+				return false;
 			}
 
 			OSD.ClearGuiText();
@@ -4246,36 +4240,27 @@ namespace BizHawk.Client.EmuHawk
 			{
 				AddOnScreenMessage($"Loaded state: {userFriendlyStateName}");
 			}
+			return true;
 		}
 
-		public void LoadQuickSave(int slot, bool suppressOSD = false)
+		public bool LoadQuickSave(int slot, bool suppressOSD = false)
 		{
-			if (!Emulator.HasSavestates())
-			{
-				return;
-			}
+			if (!Emulator.HasSavestates()) return false;
+
 			var quickSlotName = $"QuickSave{slot % 10}";
 			EmuClient.OnBeforeQuickLoad(this, quickSlotName, out var handled);
-			if (handled)
-			{
-				return;
-			}
+			if (handled) return true; // not sure
 
-			if (IsSavestateSlave)
-			{
-				Master.LoadQuickSave(SlotToInt(quickSlotName));
-				return;
-			}
+			if (IsSavestateSlave) return Master.LoadQuickSave(SlotToInt(quickSlotName));
 
 			var path = $"{SaveStatePrefix()}.{quickSlotName}.State";
 			if (!File.Exists(path))
 			{
 				AddOnScreenMessage($"Unable to load {quickSlotName}.State");
-
-				return;
+				return false;
 			}
 
-			LoadState(path, quickSlotName, suppressOSD);
+			return LoadState(path: path, userFriendlyStateName: quickSlotName, suppressOSD: suppressOSD);
 		}
 
 		public void SaveState(string path, string userFriendlyStateName, bool fromLua = false, bool suppressOSD = false)
@@ -4434,25 +4419,17 @@ namespace BizHawk.Client.EmuHawk
 			}
 		}
 
-		private void LoadStateAs()
+		private bool LoadStateAs()
 		{
-			if (!Emulator.HasSavestates())
-			{
-				return;
-			}
-
-			if (IsSavestateSlave)
-			{
-				Master.LoadStateAs();
-				return;
-			}
+			if (!Emulator.HasSavestates()) return false;
+			if (IsSavestateSlave) return Master.LoadStateAs();
 
 			var result = this.ShowFileOpenDialog(
 				discardCWDChange: true,
 				filter: EmuHawkSaveStatesFSFilterSet,
 				initDir: Config.PathEntries.SaveStateAbsolutePath(Game.System));
-			if (result is null || !File.Exists(result)) return;
-			LoadState(result, Path.GetFileName(result));
+			if (result is null || !File.Exists(result)) return false;
+			return LoadState(path: result, userFriendlyStateName: Path.GetFileName(result));
 		}
 
 		private void SelectSlot(int slot)

src/BizHawk.Client.EmuHawk/tools/BasicBot/BasicBot.cs

@@ -453,7 +453,7 @@ namespace BizHawk.Client.EmuHawk
 
 			InputManager.SyncControls(Emulator, MovieSession, Config);
 
-			MainForm.LoadQuickSave(SelectedSlot, true); // Triggers an UpdateValues call
+			_ = MainForm.LoadQuickSave(SelectedSlot, true); // Triggers an UpdateValues call
 			_lastFrameAdvanced = Emulator.Frame;
 			_doNotUpdateValues = false;
 			_startFrame = Emulator.Frame;
@@ -904,7 +904,7 @@ namespace BizHawk.Client.EmuHawk
 					reset_curent(Attempts);
 					_doNotUpdateValues = true;
 					PressButtons(true);
-					MainForm.LoadQuickSave(SelectedSlot, true);
+					_ = MainForm.LoadQuickSave(SelectedSlot, true);
 					_lastFrameAdvanced = Emulator.Frame;
 					_doNotUpdateValues = false;
 					return;
@@ -1034,7 +1034,7 @@ namespace BizHawk.Client.EmuHawk
 
 			_doNotUpdateValues = true;
 			PressButtons(true);
-			MainForm.LoadQuickSave(SelectedSlot, true); // Triggers an UpdateValues call
+			_ = MainForm.LoadQuickSave(SelectedSlot, true); // Triggers an UpdateValues call
 			_lastFrameAdvanced = Emulator.Frame;
 			_doNotUpdateValues = false;
 			_startFrame = Emulator.Frame;

src/BizHawk.Client.EmuHawk/tools/Debugger/GenericDebugger.IControlMainform.cs

@@ -11,11 +11,20 @@
 		public bool WantsToControlSavestates => false;
 
 		public void SaveState() { }
-		public void LoadState() { }
+
+		public bool LoadState()
+			=> false;
+
 		public void SaveStateAs() { }
-		public void LoadStateAs() { }
+
+		public bool LoadStateAs()
+			=> false;
+
 		public void SaveQuickSave(int slot) { }
-		public void LoadQuickSave(int slot) { }
+
+		public bool LoadQuickSave(int slot)
+			=> false;
+
 		public bool SelectSlot(int slot) => false;
 		public bool PreviousSlot() => false;
 		public bool NextSlot() => false;

src/BizHawk.Client.EmuHawk/tools/TAStudio/BookmarksBranchesBox.cs

@@ -210,15 +210,14 @@ namespace BizHawk.Client.EmuHawk
 			Tastudio.RefreshDialog();
 		}
 
-		private void LoadSelectedBranch()
+		private bool LoadSelectedBranch()
 		{
-			if (SelectedBranch != null)
-			{
-				Branches.Current = BranchView.FirstSelectedRowIndex;
-				LoadBranch(SelectedBranch);
-				BranchView.Refresh();
-				Tastudio.MainForm.AddOnScreenMessage($"Loaded branch {Branches.Current + 1}");
-			}
+			if (SelectedBranch == null) return false;
+			Branches.Current = BranchView.FirstSelectedRowIndex;
+			LoadBranch(SelectedBranch);
+			BranchView.Refresh();
+			Tastudio.MainForm.AddOnScreenMessage($"Loaded branch {Branches.Current + 1}");
+			return true;
 		}
 
 		private void BranchesContextMenu_Opening(object sender, CancelEventArgs e)
@@ -247,7 +246,7 @@ namespace BizHawk.Client.EmuHawk
 			Tastudio.MainForm.AddOnScreenMessage($"Added branch {Branches.Current + 1}");
 		}
 
-		private void PrepareHistoryAndLoadSelectedBranch()
+		private bool PrepareHistoryAndLoadSelectedBranch()
 		{
 			_backupBranch = CreateBranch();
 
@@ -263,11 +262,11 @@ namespace BizHawk.Client.EmuHawk
 			toolTip1.SetToolTip(UndoBranchButton, "Undo Branch Load");
 			_branchUndo = BranchUndo.Load;
 
-			if (BranchView.AnyRowsSelected)
-			{
-				LoadSelectedBranch();
-				LoadedCallback?.Invoke(BranchView.FirstSelectedRowIndex);
-			}
+			if (!BranchView.AnyRowsSelected) return false; // why'd we do all that then
+
+			var success = LoadSelectedBranch();
+			LoadedCallback?.Invoke(BranchView.FirstSelectedRowIndex);
+			return success;
 		}
 
 		private void LoadBranchToolStripMenuItem_Click(object sender, EventArgs e)
@@ -405,11 +404,11 @@ namespace BizHawk.Client.EmuHawk
 			AddBranchToolStripMenuItem_Click(null, null);
 		}
 
-		public void LoadBranchExternal(int slot = -1)
+		public bool LoadBranchExternal(int slot = -1)
 		{
 			if (Tastudio.AxisEditingMode)
 			{
-				return;
+				return false;
 			}
 
 			if (slot != -1)
@@ -422,11 +421,11 @@ namespace BizHawk.Client.EmuHawk
 				else
 				{
 					NonExistentBranchMessage(slot);
-					return;
+					return false;
 				}
 			}
 
-			PrepareHistoryAndLoadSelectedBranch();
+			return PrepareHistoryAndLoadSelectedBranch();
 		}
 
 		public void UpdateBranchExternal(int slot = -1)

src/BizHawk.Client.EmuHawk/tools/TAStudio/TAStudio.IControlMainForm.cs

@@ -15,25 +15,21 @@ namespace BizHawk.Client.EmuHawk
 			BookMarkControl.UpdateBranchExternal();
 		}
 
-		public void LoadState()
-		{
-			BookMarkControl.LoadBranchExternal();
-		}
+		public bool LoadState()
+			=> BookMarkControl.LoadBranchExternal();
 
 		public void SaveStateAs()
 		{
 			// dummy
 		}
 
-		public void LoadStateAs()
-		{
-			// dummy
-		}
+		public bool LoadStateAs()
+			=> false;
 
 		public void SaveQuickSave(int slot)
 			=> BookMarkControl.UpdateBranchExternal(slot - 1);
 
-		public void LoadQuickSave(int slot)
+		public bool LoadQuickSave(int slot)
 			=> BookMarkControl.LoadBranchExternal(slot - 1);
 
 		public bool SelectSlot(int slot)