Address PR feedback.

- Set _canHaveBody to true when StatusCode == 101
- Add test to check that upgraded connections are always closed when the app
  is done

Author: Cesar Blum Silveira

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

@@ -514,7 +514,7 @@ public void Write(ArraySegment<byte> data)
         {
             ProduceStartAndFireOnStarting().GetAwaiter().GetResult();
 
-            if (_canHaveBody || StatusCode == 101)
+            if (_canHaveBody)
             {
                 if (_autoChunk)
                 {
@@ -542,7 +542,7 @@ public Task WriteAsync(ArraySegment<byte> data, CancellationToken cancellationTo
                 return WriteAsyncAwaited(data, cancellationToken);
             }
 
-            if (_canHaveBody || StatusCode == 101)
+            if (_canHaveBody)
             {
                 if (_autoChunk)
                 {
@@ -568,7 +568,7 @@ public async Task WriteAsyncAwaited(ArraySegment<byte> data, CancellationToken c
         {
             await ProduceStartAndFireOnStarting();
 
-            if (_canHaveBody || StatusCode == 101)
+            if (_canHaveBody)
             {
                 if (_autoChunk)
                 {
@@ -771,11 +771,13 @@ private void CreateResponseHeader(
             // Set whether response can have body
             _canHaveBody = StatusCanHaveBody(StatusCode) && Method != "HEAD";
 
+            // Don't set the Content-Length or Transfer-Encoding headers
+            // automatically for HEAD requests or 204, 205, 304 responses.
             if (_canHaveBody)
             {
                 if (!responseHeaders.HasTransferEncoding && !responseHeaders.HasContentLength)
                 {
-                    if (appCompleted)
+                    if (appCompleted && StatusCode != 101)
                     {
                         // Since the app has completed and we are only now generating
                         // the headers we can safely set the Content-Length to 0.
@@ -790,7 +792,7 @@ private void CreateResponseHeader(
                         //
                         // A server MUST NOT send a response containing Transfer-Encoding unless the corresponding
                         // request indicates HTTP/1.1 (or later).
-                        if (_httpVersion == Http.HttpVersion.Http11)
+                        if (_httpVersion == Http.HttpVersion.Http11 && StatusCode != 101)
                         {
                             _autoChunk = true;
                             responseHeaders.SetRawTransferEncoding("chunked", _bytesTransferEncodingChunked);
@@ -804,8 +806,6 @@ private void CreateResponseHeader(
             }
             else
             {
-                // Don't set the Content-Length or Transfer-Encoding headers
-                // automatically for HEAD requests or 204, 205, 304 responses.
                 if (responseHeaders.HasTransferEncoding)
                 {
                     RejectNonBodyTransferEncodingResponse(appCompleted);
@@ -1271,8 +1271,7 @@ public bool TakeMessageHeaders(SocketInput input, FrameRequestHeaders requestHea
         public bool StatusCanHaveBody(int statusCode)
         {
             // List of status codes taken from Microsoft.Net.Http.Server.Response
-            return statusCode != 101 &&
-                   statusCode != 204 &&
+            return statusCode != 204 &&
                    statusCode != 205 &&
                    statusCode != 304;
         }

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

@@ -548,9 +548,6 @@ await connection.SendEnd(
                         "POST / HTTP/1.1",
                         "Content-Length: 3",
                         "",
-                        "101POST / HTTP/1.1",
-                        "Content-Length: 3",
-                        "",
                         "204POST / HTTP/1.1",
                         "Content-Length: 3",
                         "",
@@ -562,9 +559,6 @@ await connection.SendEnd(
                         "",
                         "200");
                     await connection.ReceiveEnd(
-                        "HTTP/1.1 101 Switching Protocols",
-                        $"Date: {testContext.DateHeaderValue}",
-                        "",
                         "HTTP/1.1 204 No Content",
                         $"Date: {testContext.DateHeaderValue}",
                         "",
@@ -583,6 +577,49 @@ await connection.ReceiveEnd(
             }
         }
 
+        [Theory]
+        [MemberData(nameof(ConnectionFilterData))]
+        public async Task ConnectionClosedAfter101Response(TestServiceContext testContext)
+        {
+            using (var server = new TestServer(async httpContext =>
+            {
+                var request = httpContext.Request;
+                var stream = await httpContext.Features.Get<IHttpUpgradeFeature>().UpgradeAsync();
+                var response = Encoding.ASCII.GetBytes("hello, world");
+                await stream.WriteAsync(response, 0, response.Length);
+            }, testContext))
+            {
+                using (var connection = server.CreateConnection())
+                {
+                    await connection.SendEnd(
+                        "GET / HTTP/1.1",
+                        "",
+                        "");
+                    await connection.ReceiveEnd(
+                        "HTTP/1.1 101 Switching Protocols",
+                        "Connection: Upgrade",
+                        $"Date: {testContext.DateHeaderValue}",
+                        "",
+                        "hello, world");
+                }
+
+                using (var connection = server.CreateConnection())
+                {
+                    await connection.SendEnd(
+                        "GET / HTTP/1.0",
+                        "Connection: kee-alive",
+                        "",
+                        "");
+                    await connection.ReceiveEnd(
+                        "HTTP/1.1 101 Switching Protocols",
+                        "Connection: Upgrade",
+                        $"Date: {testContext.DateHeaderValue}",
+                        "",
+                        "hello, world");
+                }
+            }
+        }
+
         [Theory]
         [MemberData(nameof(ConnectionFilterData))]
         public async Task ThrowingResultsIn500Response(TestServiceContext testContext)