fix Harmony issue when assembly is loaded from memory (#711)

src/SMAPI.Installer/InteractiveInstaller.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
 using System.Linq;
-using System.Threading;
 using Microsoft.Win32;
 using StardewModdingApi.Installer.Enums;
 using StardewModdingAPI.Installer.Framework;
@@ -624,7 +623,7 @@ namespace StardewModdingApi.Installer
             {
                 try
                 {
-                    this.ForceDelete(Directory.Exists(path) ? new DirectoryInfo(path) : (FileSystemInfo)new FileInfo(path));
+                    FileUtilities.ForceDelete(Directory.Exists(path) ? new DirectoryInfo(path) : (FileSystemInfo)new FileInfo(path));
                     break;
                 }
                 catch (Exception ex)
@@ -665,41 +664,6 @@ namespace StardewModdingApi.Installer
             }
         }
 
-        /// <summary>Delete a file or folder regardless of file permissions, and block until deletion completes.</summary>
-        /// <param name="entry">The file or folder to reset.</param>
-        /// <remarks>This method is mirrored from <c>FileUtilities.ForceDelete</c> in the toolkit.</remarks>
-        private void ForceDelete(FileSystemInfo entry)
-        {
-            // ignore if already deleted
-            entry.Refresh();
-            if (!entry.Exists)
-                return;
-
-            // delete children
-            if (entry is DirectoryInfo folder)
-            {
-                foreach (FileSystemInfo child in folder.GetFileSystemInfos())
-                    this.ForceDelete(child);
-            }
-
-            // reset permissions & delete
-            entry.Attributes = FileAttributes.Normal;
-            entry.Delete();
-
-            // wait for deletion to finish
-            for (int i = 0; i < 10; i++)
-            {
-                entry.Refresh();
-                if (entry.Exists)
-                    Thread.Sleep(500);
-            }
-
-            // throw exception if deletion didn't happen before timeout
-            entry.Refresh();
-            if (entry.Exists)
-                throw new IOException($"Timed out trying to delete {entry.FullName}");
-        }
-
         /// <summary>Interactively ask the user to choose a value.</summary>
         /// <param name="print">A callback which prints a message to the console.</param>
         /// <param name="message">The message to print.</param>
@@ -707,7 +671,7 @@ namespace StardewModdingApi.Installer
         /// <param name="indent">The indentation to prefix to output.</param>
         private string InteractivelyChoose(string message, string[] options, string indent = "", Action<string> print = null)
         {
-            print = print ?? this.PrintInfo;
+            print ??= this.PrintInfo;
 
             while (true)
             {

src/SMAPI/Constants.cs

@@ -61,6 +61,9 @@ namespace StardewModdingAPI
         /// <summary>The absolute path to the folder containing SMAPI's internal files.</summary>
         internal static readonly string InternalFilesPath = Program.DllSearchPath;
 
+        /// <summary>The folder containing temporary files that are only valid for the current session.</summary>
+        internal static string InternalTempFilesPath => Path.Combine(Program.DllSearchPath, ".temp");
+
         /// <summary>The file path for the SMAPI configuration file.</summary>
         internal static string ApiConfigPath => Path.Combine(Constants.InternalFilesPath, "config.json");
 

src/SMAPI/Framework/ModLoading/AssemblyLoader.cs

@@ -36,6 +36,9 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <summary>The objects to dispose as part of this instance.</summary>
         private readonly HashSet<IDisposable> Disposables = new HashSet<IDisposable>();
 
+        /// <summary>The full path to the folder in which to save rewritten assemblies.</summary>
+        private readonly string TempFolderPath;
+
 
         /*********
         ** Public methods
@@ -44,11 +47,15 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <param name="targetPlatform">The current game platform.</param>
         /// <param name="monitor">Encapsulates monitoring and logging.</param>
         /// <param name="paranoidMode">Whether to detect paranoid mode issues.</param>
-        public AssemblyLoader(Platform targetPlatform, IMonitor monitor, bool paranoidMode)
+        /// <param name="tempFolderPath">The full path to the folder in which to save rewritten assemblies.</param>
+        public AssemblyLoader(Platform targetPlatform, IMonitor monitor, bool paranoidMode, string tempFolderPath)
         {
             this.Monitor = monitor;
             this.ParanoidMode = paranoidMode;
             this.AssemblyMap = this.TrackForDisposal(Constants.GetAssemblyMap(targetPlatform));
+            this.TempFolderPath = tempFolderPath;
+
+            // init resolver
             this.AssemblyDefinitionResolver = this.TrackForDisposal(new AssemblyDefinitionResolver());
             this.AssemblyDefinitionResolver.AddSearchDirectory(Constants.ExecutionPath);
             this.AssemblyDefinitionResolver.AddSearchDirectory(Constants.InternalFilesPath);
@@ -124,9 +131,23 @@ namespace StardewModdingAPI.Framework.ModLoading
                 if (changed)
                 {
                     if (!oneAssembly)
-                        this.Monitor.Log($"      Loading {assembly.File.Name} (rewritten in memory)...", LogLevel.Trace);
+                        this.Monitor.Log($"      Loading {assembly.File.Name} (rewritten)...", LogLevel.Trace);
-                    using (MemoryStream outStream = new MemoryStream())
+
+                    if (assembly.Definition.MainModule.AssemblyReferences.Any(p => p.Name == "0Harmony"))
                     {
+                        // Note: the assembly must be loaded from disk for Harmony compatibility.
+                        // Loading it from memory sets the assembly module's FullyQualifiedName to
+                        // "<Unknown>", so Harmony incorrectly identifies the module in its
+                        // Patch.PatchMethod when handling multiple patches for the same method,
+                        // leading to "Token 0x... is not valid in the scope of module HarmonySharedState"
+                        // errors (e.g. https://smapi.io/log/A0gAsc3M).
+                        string tempPath = Path.Combine(this.TempFolderPath, $"{Path.GetFileNameWithoutExtension(assemblyPath)}.{Guid.NewGuid()}.dll");
+                        assembly.Definition.Write(tempPath);
+                        lastAssembly = Assembly.LoadFile(tempPath);
+                    }
+                    else
+                    {
+                        using MemoryStream outStream = new MemoryStream();
                         assembly.Definition.Write(outStream);
                         byte[] bytes = outStream.ToArray();
                         lastAssembly = Assembly.Load(bytes);

src/SMAPI/Framework/SCore.cs

@@ -213,6 +213,20 @@ namespace StardewModdingAPI.Framework
                 return;
             }
 #endif
+
+            // reset temp folder
+            if (Directory.Exists(Constants.InternalTempFilesPath))
+            {
+                try
+                {
+                    FileUtilities.ForceDelete(new DirectoryInfo(Constants.InternalTempFilesPath));
+                }
+                catch (Exception ex)
+                {
+                    this.Monitor.Log($"Couldn't delete temporary files at {Constants.InternalTempFilesPath}: {ex}", LogLevel.Trace);
+                }
+            }
+            Directory.CreateDirectory(Constants.InternalTempFilesPath);
         }
 
         /// <summary>Launch SMAPI.</summary>
@@ -748,7 +762,7 @@ namespace StardewModdingAPI.Framework
 
             // load mods
             IDictionary<IModMetadata, Tuple<string, string>> skippedMods = new Dictionary<IModMetadata, Tuple<string, string>>();
-            using (AssemblyLoader modAssemblyLoader = new AssemblyLoader(Constants.Platform, this.Monitor, this.Settings.ParanoidWarnings))
+            using (AssemblyLoader modAssemblyLoader = new AssemblyLoader(Constants.Platform, this.Monitor, this.Settings.ParanoidWarnings, Constants.InternalTempFilesPath))
             {
                 // init
                 HashSet<string> suppressUpdateChecks = new HashSet<string>(this.Settings.SuppressUpdateChecks, StringComparer.InvariantCultureIgnoreCase);