From 9fa8ac5762aa3d320f699238abe43a680d08298b Mon Sep 17 00:00:00 2001
From: David Maas <d.maas+git@neurogears.org>
Date: Thu, 11 Jul 2024 22:22:02 -0500
Subject: [PATCH] Fix redundant assembly resolves resulting in redundant
 assembly loads

Also added copying the NuGet.config to the repack output directory for ease of testing.

Fixes https://github.com/bonsai-rx/bonsai/issues/1901
---
 Bonsai/Bonsai.csproj                       |  1 +
 Bonsai/SystemResourcesExtensionsSupport.cs | 13 +++++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/Bonsai/Bonsai.csproj b/Bonsai/Bonsai.csproj
index 33be0269..66926e89 100644
--- a/Bonsai/Bonsai.csproj
+++ b/Bonsai/Bonsai.csproj
@@ -102,6 +102,7 @@
       </_IlRepackCommand>
     </PropertyGroup>
     <Exec WorkingDirectory="$(RepackedOutputPath)" Command="$(_IlRepackCommand.Replace('%0D', ' ').Replace('%0A', ' '))" UseCommandProcessor="false" />
+    <Copy SourceFiles="$(TargetDir)NuGet.config" DestinationFolder="$(RepackedOutputPath)" />
   </Target>
 
   <Target Name="UseRepackOutputForPackage" Condition="'$(UseRepackForBootstrapperPackage)' == 'true'" AfterTargets="BuiltProjectOutputGroup" DependsOnTargets="ConfigureRepack">
diff --git a/Bonsai/SystemResourcesExtensionsSupport.cs b/Bonsai/SystemResourcesExtensionsSupport.cs
index a0c46421..bafc660e 100644
--- a/Bonsai/SystemResourcesExtensionsSupport.cs
+++ b/Bonsai/SystemResourcesExtensionsSupport.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Concurrent;
 using System.Diagnostics;
 using System.Reflection;
 
@@ -16,19 +17,27 @@ internal static class SystemResourcesExtensionsSupport
         [Conditional("NETFRAMEWORK")]
         internal static void Initialize()
         {
+            // Assembly.Load(byte[]) always results in a new assembly so we need to manually de-duplicate them
+            ConcurrentDictionary<string, Assembly> resolveCache = new();
+
             AppDomain.CurrentDomain.AssemblyResolve += (_, args) =>
             {
                 var assemblyName = new AssemblyName(args.Name);
+
+                if (resolveCache.TryGetValue(assemblyName.Name, out var cachedResult))
+                    return cachedResult;
+
                 using var embeddedAssembly = typeof(SystemResourcesExtensionsSupport).Assembly.GetManifestResourceStream($"{nameof(Bonsai)}.{assemblyName.Name}.dll");
-                
+
                 if (embeddedAssembly is null)
-                    return null;
+                    return resolveCache.GetOrAdd(assemblyName.Name, (Assembly)null);
 
                 var assemblyBytes = new byte[embeddedAssembly.Length];
                 int readLength = embeddedAssembly.Read(assemblyBytes, 0, assemblyBytes.Length);
                 Debug.Assert(readLength == assemblyBytes.Length);
 
                 var result = Assembly.Load(assemblyBytes);
+                result = resolveCache.GetOrAdd(assemblyName.Name, result);
                 Debug.WriteLine($"Redirecting '{args.Name}' to embedded '{result.FullName}'");
                 return result;
             };