Override TryComputeLength(...) in web host HttpContent implementations

src/System.Web.Http.WebHost/HttpControllerHandler.cs

@@ -717,14 +717,17 @@ public Task WriteToStreamAsync(Stream stream, TransportContext context)
                 return SerializeToStreamAsync(stream, context);
             }
 
-            public bool TryCalculateLength(out long length)
+            public Task<Stream> GetContentReadStreamAsync()
             {
-                return TryComputeLength(out length);
+                return CreateContentReadStreamAsync();
             }
 
-            public Task<Stream> GetContentReadStreamAsync()
+            protected override bool TryComputeLength(out long length)
             {
-                return CreateContentReadStreamAsync();
+                // Do not attempt to calculate length because SeekableBufferedRequestStream (for example)
+                // may report 0 until the underlying Stream has been read to end.
+                length = 0L;
+                return false;
             }
         }
 
@@ -762,7 +765,10 @@ protected override Task<Stream> CreateContentReadStreamAsync()
 
             protected override bool TryComputeLength(out long length)
             {
-                return StreamContent.TryCalculateLength(out length);
+                // Do not attempt to calculate length because SeekableBufferedRequestStream (for example)
+                // may report 0 until the underlying Stream has been read to end.
+                length = 0L;
+                return false;
             }
         }
     }

test/System.Web.Http.WebHost.Test/HttpControllerHandlerTest.cs

@@ -73,6 +73,24 @@ public void ConvertRequest_Creates_HttpRequestMessage_For_All_HttpMethods(HttpMe
             Assert.Equal(httpMethod, request.Method);
         }
 
+        [Fact]
+        public void ConvertRequest_DoesNotAddContentLength()
+        {
+            // Arrange
+            HttpContextBase contextBase = CreateStubContextBase("Get", new MemoryStream());
+
+            // Act
+            HttpRequestMessage request = HttpControllerHandler.ConvertRequest(contextBase);
+
+            // Assert
+            var headers = request.Content.Headers;
+            Assert.NotNull(headers);
+            Assert.Null(headers.ContentLength);
+
+            IEnumerable<string> unused;
+            Assert.False(headers.TryGetValues("Content-Length", out unused));
+        }
+
         [Fact]
         public void ConvertRequest_Copies_Headers_And_Content_Headers()
         {
@@ -130,8 +148,10 @@ public void ConvertRequest_AddsOwinEnvironment_WhenPresentInHttpContext()
             {
                 HttpRequestBase stubRequest = CreateStubRequestBase("IgnoreMethod", ignoreStream);
                 IDictionary<string, object> expectedEnvironment = new Dictionary<string, object>();
-                IDictionary items = new Hashtable();
-                items.Add(HttpControllerHandler.OwinEnvironmentHttpContextKey, expectedEnvironment);
+                IDictionary items = new Hashtable
+                {
+                    { HttpControllerHandler.OwinEnvironmentHttpContextKey, expectedEnvironment }
+                };
                 HttpContextBase context = CreateStubContextBase(stubRequest, items);
 
                 // Act
@@ -1946,13 +1966,6 @@ private static HttpResponseBase CreateStubResponseBase()
             return new Mock<HttpResponseBase>().Object;
         }
 
-        private static HttpResponseBase CreateStubResponseBase(CancellationToken clientDisconnectedToken)
-        {
-            Mock<HttpResponseBase> mock = new Mock<HttpResponseBase>();
-            mock.Setup(r => r.ClientDisconnectedToken).Returns(clientDisconnectedToken);
-            return mock.Object;
-        }
-
         private static HttpResponseBase CreateStubResponseBase(Stream outputStream)
         {
             Mock<HttpResponseBase> responseBaseMock = new Mock<HttpResponseBase>();