Copy connection middleware when using ListenLocalHost (#2447)

- Connection middleware got removed during Clone when using ListenLocalhost

src/Kestrel.Core/ListenOptions.cs

@@ -24,7 +24,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
         private FileHandleType _handleType;
         private HttpProtocols _protocols = HttpProtocols.Http1;
         internal bool _isHttp2Supported;
-        private readonly List<Func<ConnectionDelegate, ConnectionDelegate>> _components = new List<Func<ConnectionDelegate, ConnectionDelegate>>();
+        internal readonly List<Func<ConnectionDelegate, ConnectionDelegate>> _middleware = new List<Func<ConnectionDelegate, ConnectionDelegate>>();
 
         internal ListenOptions(IPEndPoint endPoint)
         {
@@ -181,7 +181,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
 
         public IConnectionBuilder Use(Func<ConnectionDelegate, ConnectionDelegate> middleware)
         {
-            _components.Add(middleware);
+            _middleware.Add(middleware);
             return this;
         }
 
@@ -192,9 +192,9 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
                 return Task.CompletedTask;
             };
 
-            for (int i = _components.Count - 1; i >= 0; i--)
+            for (int i = _middleware.Count - 1; i >= 0; i--)
             {
-                var component = _components[i];
+                var component = _middleware[i];
                 app = component(app);
             }
 

src/Kestrel.Core/LocalhostListenOptions.cs

@@ -72,7 +72,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
         }
 
         // used for cloning to two IPEndpoints
-        private ListenOptions Clone(IPAddress address)
+        internal ListenOptions Clone(IPAddress address)
         {
             var options = new ListenOptions(new IPEndPoint(address, IPEndPoint.Port))
             {
@@ -81,6 +81,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
                 NoDelay = NoDelay,
                 Protocols = Protocols,
             };
+
+            options._middleware.AddRange(_middleware);
             options.ConnectionAdapters.AddRange(ConnectionAdapters);
             return options;
         }

test/Kestrel.Core.Tests/ListenOptionsTests.cs

@@ -3,6 +3,10 @@
 
 using System;
 using System.Net;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Server.Kestrel.Core.Adapter.Internal;
+using Microsoft.AspNetCore.Testing;
+using Microsoft.Extensions.DependencyInjection;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
@@ -25,5 +29,35 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             ex = Assert.Throws<NotSupportedException>(() => listenOptions.Protocols = HttpProtocols.Http2);
             Assert.Equal(CoreStrings.Http2NotSupported, ex.Message);
         }
+
+        [Fact]
+        public void LocalHostListenOptionsClonesConnectionMiddleware()
+        {
+            var localhostListenOptions = new LocalhostListenOptions(1004);
+            localhostListenOptions.ConnectionAdapters.Add(new PassThroughConnectionAdapter());
+            var serviceProvider = new ServiceCollection().BuildServiceProvider();
+            localhostListenOptions.KestrelServerOptions = new KestrelServerOptions()
+            {
+                ApplicationServices = serviceProvider
+            };
+            var middlewareRan = false;
+            localhostListenOptions.Use(next =>
+            {
+                middlewareRan = true;
+                return context => Task.CompletedTask;
+            });
+
+            var clone = localhostListenOptions.Clone(IPAddress.IPv6Loopback);
+            var app = clone.Build();
+
+            // Execute the delegate
+            app(null);
+
+            Assert.True(middlewareRan);
+            Assert.NotNull(clone.KestrelServerOptions);
+            Assert.NotNull(serviceProvider);
+            Assert.Same(serviceProvider, clone.ApplicationServices);
+            Assert.Single(clone.ConnectionAdapters);
+        }
     }
 }