Allow Lua to reliably restore pause state after a seek.

Author: SuuperW

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

@@ -228,7 +228,7 @@ public void SpeedMode(int percent)
 
 		public Point TransformPoint(Point point) => _displayManager.TransformPoint(point);
 
-		public void Unpause() => _mainForm.UnpauseEmulator();
+		public bool Unpause() => _mainForm.UnpauseEmulator();
 
 		public void UnpauseAv() => _mainForm.PauseAvi = false;
 

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

@@ -154,7 +154,10 @@ public interface IEmuClientApi : IDisposable, IExternalApi
 
 		Point TransformPoint(Point point);
 
-		void Unpause();
+		/// <returns>True if <see cref="Pause"/> should be called if you want to restore the previous pause state.
+		/// <br/>Note that this is not the same as checking <see cref="IsPaused"/> before unpausing.
+		/// If the user was holding frame advance, emulation will have already been unpaused and releasing frame advance will not pause.</returns>
+		bool Unpause();
 
 		void UnpauseAv();
 

src/BizHawk.Client.Common/IMainFormForApi.cs

@@ -128,7 +128,7 @@ public interface IMainFormForApi
 		void ToggleSound();
 
 		/// <remarks>only referenced from <see cref="EmuClientApi"/></remarks>
-		void UnpauseEmulator();
+		bool UnpauseEmulator();
 
 		/// <remarks>only referenced from <see cref="EmuClientApi"/></remarks>
 		event BeforeQuickLoadEventHandler QuicksaveLoad;

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

@@ -304,8 +304,8 @@ public LuaTable TransformPoint(int x, int y) {
 		}
 
 		[LuaMethodExample("client.unpause( );")]
-		[LuaMethod("unpause", "Unpauses the emulator")]
-		public void Unpause()
+		[LuaMethod("unpause", "Unpauses the emulator. Returns True if client.pause should be called if you want to restore the previous pause state. Note that this is not the same as checking client.ispaused before unpausing. If the user was holding frame advance, emulation will have already been unpaused and releasing frame advance will not pause.")]
+		public bool Unpause()
 			=> APIs.EmuClient.Unpause();
 
 		[LuaMethodExample("client.unpause_av( );")]

src/BizHawk.Client.EmuHawk/IMainFormForTools.cs

@@ -85,7 +85,7 @@ public interface IMainFormForTools : IDialogController
 		void TogglePause();
 
 		/// <remarks>referenced by 3 or more tools</remarks>
-		void UnpauseEmulator();
+		bool UnpauseEmulator();
 
 		/// <remarks>only referenced from <see cref="BasicBot"/></remarks>
 		void Unthrottle();

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -1367,9 +1367,11 @@ public void PauseEmulator()
 			EmulatorPaused = true;
 		}
 
-		public void UnpauseEmulator()
+		public bool UnpauseEmulator()
 		{
+			bool ret = _emulatorPaused;
 			EmulatorPaused = false;
+			return ret;
 		}
 
 		public void TogglePause()

src/BizHawk.Client.EmuHawk/RetroAchievements/RAIntegration.cs

@@ -137,7 +137,7 @@ public RAIntegration(
 				clientVer: $"{VersionInfo.MainVersion}{(VersionInfo.DeveloperBuild ? "-dev" : string.Empty)}");
 
 			_isActive = () => !Emu.IsNull();
-			_unpause = _mainForm.UnpauseEmulator;
+			_unpause = () => _ = _mainForm.UnpauseEmulator();
 			_pause = _mainForm.PauseEmulator;
 			_rebuildMenu = RebuildMenu;
 			_estimateTitle = buffer =>