Handle errors when saving config file.

Author: SuuperW

src/BizHawk.Client.Common/config/ConfigService.cs

@@ -104,19 +104,14 @@ public static bool IsFromSameVersion(string filepath, out string msg)
 			return config ?? new T();
 		}
 
-		public static void Save(string filepath, object config)
+		public static FileWriteResult Save(string filepath, object config)
 		{
-			var file = new FileInfo(filepath);
-			try
+			return FileWriter.Write(filepath, (fs) =>
 			{
-				using var writer = file.CreateText();
+				using var writer = new StreamWriter(fs);
 				var w = new JsonTextWriter(writer) { Formatting = Formatting.Indented };
 				Serializer.Serialize(w, config);
-			}
-			catch
-			{
-				/* Eat it */
-			}
+			});
 		}
 
 		// movie 1.0 header stuff

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

@@ -979,8 +979,15 @@ private void HkOverInputMenuItem_Click(object sender, EventArgs e)
 
 		private void SaveConfigMenuItem_Click(object sender, EventArgs e)
 		{
-			SaveConfig();
-			AddOnScreenMessage("Saved settings");
+			FileWriteResult result = SaveConfig();
+			if (result.IsError)
+			{
+				this.ErrorMessageBox(result);
+			}
+			else
+			{
+				AddOnScreenMessage("Saved settings");
+			}
 		}
 
 		private void SaveConfigAsMenuItem_Click(object sender, EventArgs e)
@@ -992,8 +999,15 @@ private void SaveConfigAsMenuItem_Click(object sender, EventArgs e)
 				initFileName: file);
 			if (result is not null)
 			{
-				SaveConfig(result);
-				AddOnScreenMessage("Copied settings");
+				FileWriteResult saveResult = SaveConfig(result);
+				if (saveResult.IsError)
+				{
+					this.ErrorMessageBox(saveResult);
+				}
+				else
+				{
+					AddOnScreenMessage("Copied settings");
+				}
 			}
 		}
 

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -875,7 +875,12 @@ private void CheckMayCloseAndCleanup(object/*?*/ closingSender, CancelEventArgs
 				StopAv();
 			}
 
-			SaveConfig(); // TODO: Handle failure.
+			TryAgainResult configSaveResult = this.DoWithTryAgainBox(() => SaveConfig(), "Failed to save config file.");
+			if (configSaveResult == TryAgainResult.Canceled)
+			{
+				closingArgs.Cancel = true;
+				return;
+			}
 
 			if (!CloseGame())
 			{
@@ -2417,7 +2422,7 @@ public ISettingsAdapter GetSettingsAdapterForLoadedCore<T>()
 		public SettingsAdapter GetSettingsAdapterForLoadedCoreUntyped()
 			=> new(Emulator, static () => true, HandlePutCoreSettings, MayPutCoreSyncSettings, HandlePutCoreSyncSettings);
 
-		private void SaveConfig(string path = "")
+		private FileWriteResult SaveConfig(string path = "")
 		{
 			if (Config.SaveWindowPosition)
 			{
@@ -2443,7 +2448,7 @@ private void SaveConfig(string path = "")
 			}
 
 			CommitCoreSettingsToConfig();
-			ConfigService.Save(path, Config);
+			return ConfigService.Save(path, Config);
 		}
 
 		private void ToggleFps()
@@ -3943,10 +3948,7 @@ private bool CloseGame(bool clearSram = false)
 			}
 			// There is a cheats tool, but cheats can be active while the "cheats tool" is not. And have auto-save option.
 			TryAgainResult cheatSaveResult = this.DoWithTryAgainBox(CheatList.SaveOnClose, "Failed to save cheats.");
-			if (cheatSaveResult == TryAgainResult.Canceled)
-			{
-				return false;
-			}
+			if (cheatSaveResult == TryAgainResult.Canceled) return false;
 
 			// If TAStudio is open, we already asked about saving the movie.
 			if (!Tools.IsLoaded<TAStudio>())

src/BizHawk.Client.EmuHawk/config/ControllerConfig.cs

@@ -470,7 +470,11 @@ private void ButtonSaveDefaults_Click(object sender, EventArgs e)
 
 				SaveToDefaults(cd);
 
-				ConfigService.Save(Config.ControlDefaultPath, cd);
+				FileWriteResult saveResult = ConfigService.Save(Config.ControlDefaultPath, cd);
+				if (saveResult.IsError)
+				{
+					this.ErrorMessageBox(saveResult);
+				}
 			}
 		}