add apply_save_fix command

docs/release-notes.md

@@ -13,6 +13,7 @@
 
 * For modders:
   * World events are now raised for the volcano levels.
+  * Added `apply_save_fix` command to reapply a save migration in exceptional cases. This should be used with extreme care. Type `help apply_save_fix` for details.
 
 For the web UI:
   * Fixed edge cases in SMAPI log parsing.

src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/ApplySaveFixCommand.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using StardewValley;
+
+namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Other
+{
+    /// <summary>A command which runs one of the game's save migrations.</summary>
+    internal class ApplySaveFixCommand : TrainerCommand
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        public ApplySaveFixCommand()
+            : base("apply_save_fix", "Apply one of the game's save migrations to the currently loaded save. WARNING: This may corrupt or make permanent changes to your save. DO NOT USE THIS unless you're absolutely sure.\n\nUsage: apply_save_fix list\nList all valid save IDs.\n\nUsage: apply_save_fix <fix ID>\nApply the named save fix.") { }
+
+        /// <summary>Handle the command.</summary>
+        /// <param name="monitor">Writes messages to the console and log file.</param>
+        /// <param name="command">The command name.</param>
+        /// <param name="args">The command arguments.</param>
+        public override void Handle(IMonitor monitor, string command, ArgumentParser args)
+        {
+            // get fix ID
+            if (!args.TryGet(0, "fix_id", out string rawFixId, required: false))
+            {
+                monitor.Log("Invalid usage. Type 'help apply_save_fix' for details.", LogLevel.Error);
+                return;
+            }
+            rawFixId = rawFixId.Trim();
+
+
+            // list mode
+            if (rawFixId == "list")
+            {
+                monitor.Log("Valid save fix IDs:\n  - " + string.Join("\n  - ", this.GetSaveIds()), LogLevel.Info);
+                return;
+            }
+
+            // validate fix ID
+            if (!Enum.TryParse(rawFixId, ignoreCase: true, out SaveGame.SaveFixes fixId))
+            {
+                monitor.Log($"Invalid save ID '{rawFixId}'. Type 'help apply_save_fix' for details.", LogLevel.Error);
+                return;
+            }
+
+            // apply
+            monitor.Log("THIS MAY CAUSE PERMANENT CHANGES TO YOUR SAVE FILE. If you're not sure, exit your game without saving to avoid issues.", LogLevel.Warn);
+            monitor.Log($"Trying to apply save fix ID: '{fixId}'.", LogLevel.Warn);
+            try
+            {
+                Game1.applySaveFix(fixId);
+                monitor.Log("Save fix applied.", LogLevel.Info);
+            }
+            catch (Exception ex)
+            {
+                monitor.Log("Applying save fix failed. The save may be in an invalid state; you should exit your game now without saving to avoid issues.", LogLevel.Error);
+                monitor.Log($"Technical details: {ex}", LogLevel.Debug);
+            }
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Get the valid save fix IDs.</summary>
+        private IEnumerable<string> GetSaveIds()
+        {
+            foreach (SaveGame.SaveFixes id in Enum.GetValues(typeof(SaveGame.SaveFixes)))
+            {
+                if (id == SaveGame.SaveFixes.MAX)
+                    continue;
+
+                yield return id.ToString();
+            }
+        }
+    }
+}