Handle null valued headers #158

src/Microsoft.Net.Http.Server/RequestProcessing/Response.cs

@@ -575,7 +575,6 @@ namespace Microsoft.Net.Http.Server
             {
                 if (headerPair.Value.Count == 0)
                 {
-                    // TODO: Have the collection exclude empty headers.
                     continue;
                 }
                 // See if this is an unknown header
@@ -602,7 +601,6 @@ namespace Microsoft.Net.Http.Server
                     {
                         if (headerPair.Value.Count == 0)
                         {
-                            // TODO: Have the collection exclude empty headers.
                             continue;
                         }
                         headerName = headerPair.Key;
@@ -632,7 +630,7 @@ namespace Microsoft.Net.Http.Server
                                 unknownHeaders[_nativeResponse.Response_V1.Headers.UnknownHeaderCount].pName = (sbyte*)gcHandle.AddrOfPinnedObject();
 
                                 // Add Value
-                                headerValue = headerValues[headerValueIndex];
+                                headerValue = headerValues[headerValueIndex] ?? string.Empty;
                                 bytes = new byte[HeaderEncoding.GetByteCount(headerValue)];
                                 unknownHeaders[_nativeResponse.Response_V1.Headers.UnknownHeaderCount].RawValueLength = (ushort)bytes.Length;
                                 HeaderEncoding.GetBytes(headerValue, 0, bytes.Length, bytes, 0);
@@ -644,9 +642,7 @@ namespace Microsoft.Net.Http.Server
                         }
                         else if (headerPair.Value.Count == 1)
                         {
-                            headerValue = headerValues[0];
-                            if (headerValue != null)
-                            {
+                            headerValue = headerValues[0] ?? string.Empty;
                             bytes = new byte[HeaderEncoding.GetByteCount(headerValue)];
                             pKnownHeaders[lookup].RawValueLength = (ushort)bytes.Length;
                             HeaderEncoding.GetBytes(headerValue, 0, bytes.Length, bytes, 0);
@@ -654,7 +650,6 @@ namespace Microsoft.Net.Http.Server
                             pinnedHeaders.Add(gcHandle);
                             pKnownHeaders[lookup].pRawValue = (sbyte*)gcHandle.AddrOfPinnedObject();
                         }
-                        }
                         else
                         {
                             if (knownHeaderInfo == null)
@@ -681,7 +676,7 @@ namespace Microsoft.Net.Http.Server
                             for (int headerValueIndex = 0; headerValueIndex < headerValues.Count; headerValueIndex++)
                             {
                                 // Add Value
-                                headerValue = headerValues[headerValueIndex];
+                                headerValue = headerValues[headerValueIndex] ?? string.Empty;
                                 bytes = new byte[HeaderEncoding.GetByteCount(headerValue)];
                                 nativeHeaderValues[header.KnownHeaderCount].RawValueLength = (ushort)bytes.Length;
                                 HeaderEncoding.GetBytes(headerValue, 0, bytes.Length, bytes, 0);

test/Microsoft.AspNet.Server.WebListener.FunctionalTests/ResponseHeaderTests.cs

@@ -23,7 +23,7 @@ using System.Net.Http;
 using System.Text;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Features;
-using Microsoft.AspNet.Http.Internal;
+using Microsoft.Extensions.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNet.Server.WebListener
@@ -259,6 +259,58 @@ namespace Microsoft.AspNet.Server.WebListener
             }
         }
 
+        [Theory, MemberData(nameof(NullHeaderData))]
+        public async Task Headers_IgnoreNullHeaders(string headerName, StringValues headerValue, StringValues expectedValue)
+        {
+            string address;
+            using (Utilities.CreateHttpServer(out address, httpContext =>
+            {
+                var responseHeaders = httpContext.Response.Headers;
+                responseHeaders.Add(headerName, headerValue);
+                return Task.FromResult(0);
+            }))
+            {
+                HttpResponseMessage response = await SendRequestAsync(address);
+                response.EnsureSuccessStatusCode();
+                var headers = response.Headers;
+
+                if (expectedValue.Count == 0)
+                {
+                    Assert.False(headers.Contains(headerName));
+                }
+                else
+                {
+                    Assert.True(headers.Contains(headerName));
+                    Assert.Equal(headers.GetValues(headerName), expectedValue);
+                }
+            }
+        }
+
+        public static TheoryData<string, StringValues, StringValues> NullHeaderData
+        {
+            get
+            {
+                var dataset = new TheoryData<string, StringValues, StringValues>();
+
+                // Unknown headers
+                dataset.Add("NullString", (string)null, (string)null);
+                dataset.Add("EmptyString", "", "");
+                dataset.Add("NullStringArray", new string[] { null }, "");
+                dataset.Add("EmptyStringArray", new string[] { "" }, "");
+                dataset.Add("MixedStringArray", new string[] { null, "" }, new string[] { "", "" });
+                // Known headers
+                dataset.Add("Location", (string)null, (string)null);
+                dataset.Add("Location", "", (string)null);
+                dataset.Add("Location", new string[] { null }, (string)null);
+                dataset.Add("Location", new string[] { "" }, (string)null);
+                dataset.Add("Location", new string[] { "a" }, "a");
+                dataset.Add("Location", new string[] { null, "" }, (string)null);
+                dataset.Add("Location", new string[] { null, "", "a", "b" }, new string[] { "a", "b" });
+
+                return dataset;
+            }
+        }
+
         private async Task<HttpResponseMessage> SendRequestAsync(string uri)
         {
             using (HttpClient client = new HttpClient())