Inherit patcher types

BepInEx.Core/Bootstrap/TypeLoader.cs

@@ -63,6 +63,38 @@ public static class TypeLoader
 
     public static HashSet<string> SearchDirectories = new();
 
+    private static readonly Dictionary<string, string> AssemblyPathByName = new(StringComparer.InvariantCultureIgnoreCase);
+
+    /// <summary>
+    ///     Maps every managed assembly file in a directory to its assembly name, so files whose
+    ///     filename does not match the assembly name (e.g. renamed by the user) still resolve.
+    ///     First file wins when two files share an assembly name.
+    /// </summary>
+    public static void RegisterAssemblyPaths(string directory)
+    {
+        if (!Directory.Exists(directory))
+            return;
+
+        foreach (var dll in Directory.GetFiles(Path.GetFullPath(directory), "*.dll", SearchOption.AllDirectories))
+        {
+            AssemblyName name;
+            try
+            {
+                name = AssemblyName.GetAssemblyName(dll);
+            }
+            catch (Exception)
+            {
+                continue;
+            }
+
+            if (!AssemblyPathByName.ContainsKey(name.Name))
+                AssemblyPathByName[name.Name] = dll;
+        }
+    }
+
+    public static bool TryGetRegisteredAssemblyPath(string name, out string path) =>
+        AssemblyPathByName.TryGetValue(name, out path) && File.Exists(path);
+
     #region Config
 
     private static readonly ConfigEntry<bool> EnableAssemblyCache = ConfigFile.CoreConfig.Bind(
@@ -104,6 +136,15 @@ public static AssemblyDefinition CecilResolveOnFailure(object sender, AssemblyNa
                 return assembly;
         }
 
+        if (TryGetRegisteredAssemblyPath(name.Name, out var mappedPath))
+        {
+            try
+            {
+                return AssemblyDefinition.ReadAssembly(mappedPath, ReaderParameters);
+            }
+            catch (BadImageFormatException) { }
+        }
+
         return AssemblyResolve?.Invoke(sender, reference);
     }
 

BepInEx.Core/Contract/Attributes.cs

@@ -254,12 +254,27 @@ public static class MetadataHelper
 {
     internal static bool TypeInheretsFrom(TypeReference derived, Type type)
     {
-        var td = derived.Resolve();
+        TypeDefinition td;
+        try
+        {
+            td = derived.Resolve();
+        }
+        catch (AssemblyResolutionException)
+        {
+            return false;
+        }
         while (td != null)
         {
             if (td.FullName == type.FullName)
                 return true;
-            td = td.BaseType?.Resolve();
+            try
+            {
+                td = td.BaseType?.Resolve();
+            }
+            catch (AssemblyResolutionException)
+            {
+                return false;
+            }
         }
         return false;
     }

BepInEx.Preloader.Core/Patching/AssemblyPatcher.cs

@@ -20,8 +20,6 @@ namespace BepInEx.Preloader.Core.Patching;
 /// </summary>
 public class AssemblyPatcher : IDisposable
 {
-    private static readonly string CurrentAssemblyName = Assembly.GetExecutingAssembly().GetName().Name;
-
     private Func<byte[], string, Assembly> assemblyLoader;
 
     public AssemblyPatcher(Func<byte[], string, Assembly> assemblyLoader)
@@ -115,12 +113,11 @@ private PatcherPluginMetadata ToPatcherPlugin(TypeDefinition type, string assemb
 
     private bool HasPatcherPlugins(AssemblyDefinition ass)
     {
-        if (ass.MainModule.AssemblyReferences.All(r => r.Name != CurrentAssemblyName) &&
-            ass.Name.Name != CurrentAssemblyName)
-            return false;
-        if (ass.MainModule.GetTypeReferences().All(r => r.FullName != typeof(BasePatcher).FullName))
-            return false;
-
+        var typeReferences = ass.MainModule.GetTypeReferences().ToList();
+        if (typeReferences.All(r => r.FullName != typeof(BasePatcher).FullName))
+        {
+            return typeReferences.Any(r => MetadataHelper.TypeInheretsFrom(r, typeof(BasePatcher)));
+        }
         return true;
     }
 
@@ -135,6 +132,8 @@ public void AddPatchersFromDirectory(string directory)
 
         var sortedPatchers = new List<PatchDefinition>();
 
+        TypeLoader.RegisterAssemblyPaths(directory);
+
         var patchers = TypeLoader.FindPluginTypes(directory, ToPatcherPlugin, HasPatcherPlugins);
 
         // TODO: Add dependency ordering and process attribute filtering

BepInEx.Preloader.Core/Patching/Attributes.cs

@@ -58,7 +58,7 @@ private static Version TryParseLongVersion(string version)
 
     internal static PatcherPluginInfoAttribute FromCecilType(TypeDefinition td)
     {
-        var attr = MetadataHelper.GetCustomAttributes<PatcherPluginInfoAttribute>(td, false).FirstOrDefault();
+        var attr = MetadataHelper.GetCustomAttributes<PatcherPluginInfoAttribute>(td, false, true).FirstOrDefault();
 
         if (attr == null)
             return null;

Runtimes/NET/BepInEx.NET.Shared/SharedEntrypoint.cs

@@ -78,6 +78,15 @@ public static Assembly LocalResolve(object sender, ResolveEventArgs args)
              || LocalUtility.TryResolveDllAssembly(assemblyName, Paths.PluginPath, out foundAssembly))
                 return foundAssembly;
 
+            if (Bootstrap.TypeLoader.TryGetRegisteredAssemblyPath(assemblyName.Name, out var mappedPath))
+            {
+                try
+                {
+                    return Utility.LoadContext.LoadFromAssemblyPath(mappedPath);
+                }
+                catch (Exception) { }
+            }
+
             return null;
         }
     }