Disable automatic chunking for all non keep-alive requests

- Fixes a bug where Upgrade requests (e.g. WebSockets) would be chunked
- Allows chunking to be disabled by setting "Connection: close" on the response

src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/Frame.cs

@@ -723,14 +723,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
             var end = SocketOutput.ProducingStart();
             if (_keepAlive && hasConnection)
             {
-                foreach (var connectionValue in responseHeaders.HeaderConnection)
+                var connectionValue = responseHeaders.HeaderConnection.ToString();
-                {
+                _keepAlive = connectionValue.Equals("keep-alive", StringComparison.OrdinalIgnoreCase);
-                    if (connectionValue.IndexOf("close", StringComparison.OrdinalIgnoreCase) != -1)
-                    {
-                        _keepAlive = false;
-                        break;
-                    }
-                }
             }
 
             if (!responseHeaders.HasTransferEncoding && !responseHeaders.HasContentLength)
@@ -746,7 +740,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
                         responseHeaders.SetRawContentLength("0", _bytesContentLengthZero);
                     }
                 }
-                else
+                else if(_keepAlive)
                 {
                     // Note for future reference: never change this to set _autoChunk to true on HTTP/1.0
                     // connections, even if we were to infer the client supports it because an HTTP/1.0 request

test/Microsoft.AspNetCore.Server.KestrelTests/ChunkedResponseTests.cs

@@ -63,42 +63,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
 
         [Theory]
         [MemberData(nameof(ConnectionFilterData))]
-        public async Task ResponsesAreChunkedAutomaticallyForHttp11NonKeepAliveRequests(TestServiceContext testContext)
+        public async Task ResponsesAreNotChunkedAutomaticallyForHttp10RequestsAndHttp11NonKeepAliveRequests(TestServiceContext testContext)
-        {
-            using (var server = new TestServer(async httpContext =>
-            {
-                var response = httpContext.Response;
-                await response.Body.WriteAsync(Encoding.ASCII.GetBytes("Hello "), 0, 6);
-                await response.Body.WriteAsync(Encoding.ASCII.GetBytes("World!"), 0, 6);
-            }, testContext))
-            {
-                using (var connection = server.CreateConnection())
-                {
-                    await connection.SendEnd(
-                        "GET / HTTP/1.1",
-                        "Connection: close",
-                        "",
-                        "");
-                    await connection.ReceiveEnd(
-                        "HTTP/1.1 200 OK",
-                        "Connection: close",
-                        $"Date: {testContext.DateHeaderValue}",
-                        "Transfer-Encoding: chunked",
-                        "",
-                        "6",
-                        "Hello ",
-                        "6",
-                        "World!",
-                        "0",
-                        "",
-                        "");
-                }
-            }
-        }
-
-        [Theory]
-        [MemberData(nameof(ConnectionFilterData))]
-        public async Task ResponsesAreNotChunkedAutomaticallyForHttp10Requests(TestServiceContext testContext)
         {
             using (var server = new TestServer(async httpContext =>
             {
@@ -111,6 +76,51 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 {
                     await connection.SendEnd(
                         "GET / HTTP/1.0",
+                        "Connection: keep-alive",
+                        "",
+                        "");
+                    await connection.ReceiveEnd(
+                        "HTTP/1.1 200 OK",
+                        "Connection: close",
+                        $"Date: {testContext.DateHeaderValue}",
+                        "",
+                        "Hello World!");
+                }
+
+                using (var connection = server.CreateConnection())
+                {
+                    await connection.SendEnd(
+                        "GET / HTTP/1.1",
+                        "Connection: close",
+                        "",
+                        "");
+                    await connection.ReceiveEnd(
+                        "HTTP/1.1 200 OK",
+                        "Connection: close",
+                        $"Date: {testContext.DateHeaderValue}",
+                        "",
+                        "Hello World!");
+                }
+            }
+        }
+
+
+        [Theory]
+        [MemberData(nameof(ConnectionFilterData))]
+        public async Task SettingConnectionCloseHeaderInAppDisablesChunking(TestServiceContext testContext)
+        {
+            using (var server = new TestServer(async httpContext =>
+            {
+                var response = httpContext.Response;
+                response.Headers["Connection"] = "close";
+                await response.Body.WriteAsync(Encoding.ASCII.GetBytes("Hello "), 0, 6);
+                await response.Body.WriteAsync(Encoding.ASCII.GetBytes("World!"), 0, 6);
+            }, testContext))
+            {
+                using (var connection = server.CreateConnection())
+                {
+                    await connection.SendEnd(
+                        "GET / HTTP/1.1",
                         "",
                         "");
                     await connection.ReceiveEnd(

test/Microsoft.AspNetCore.Server.KestrelTests/EngineTests.cs

@@ -120,7 +120,6 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
             engine.Dispose();
         }
 
-
         [Theory]
         [MemberData(nameof(ConnectionFilterData))]
         public async Task Http10RequestReceivesHttp11Response(TestServiceContext testContext)
@@ -143,7 +142,6 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
             }
         }
 
-
         [Theory]
         [MemberData(nameof(ConnectionFilterData))]
         public async Task Http11(TestServiceContext testContext)
@@ -1310,5 +1308,43 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 }
             }
         }
+
+        [Theory]
+        [MemberData(nameof(ConnectionFilterData))]
+        public async Task UpgradeRequestIsNotKeptAliveOrChunked(TestServiceContext testContext)
+        {
+            using (var server = new TestServer(async context =>
+            {
+                var upgradeFeature = context.Features.Get<IHttpUpgradeFeature>();
+                var duplexStream = await upgradeFeature.UpgradeAsync();
+
+                while (true)
+                {
+                    var buffer = new byte[8192];
+                    var count = await duplexStream.ReadAsync(buffer, 0, buffer.Length);
+                    if (count == 0)
+                    {
+                        break;
+                    }
+                    await duplexStream.WriteAsync(buffer, 0, count);
+                }
+            }, testContext))
+            {
+                using (var connection = server.CreateConnection())
+                {
+                    await connection.SendEnd(
+                        "GET / HTTP/1.1",
+                        "Connection: Upgrade",
+                        "",
+                        "Hello World");
+                    await connection.ReceiveEnd(
+                        "HTTP/1.1 101 Switching Protocols",
+                        "Connection: Upgrade",
+                        $"Date: {testContext.DateHeaderValue}",
+                        "",
+                        "Hello World");
+                }
+            }
+        }
     }
 }