From a069f6b636e343f7a1839783ee23f9ae7eca32c3 Mon Sep 17 00:00:00 2001
From: John Luo <jt.luo@mail.utoronto.ca>
Date: Wed, 21 Sep 2016 12:48:00 -0700
Subject: [PATCH] Store each header value separately

---
 .../CacheEntry/CacheEntrySerializer.cs        | 26 +++++++++++---
 .../CacheEntrySerializerTests.cs              | 35 +++++++++++++++++++
 2 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/src/Microsoft.AspNetCore.ResponseCaching/CacheEntry/CacheEntrySerializer.cs b/src/Microsoft.AspNetCore.ResponseCaching/CacheEntry/CacheEntrySerializer.cs
index 385d5ebf78..21534dd13f 100644
--- a/src/Microsoft.AspNetCore.ResponseCaching/CacheEntry/CacheEntrySerializer.cs
+++ b/src/Microsoft.AspNetCore.ResponseCaching/CacheEntry/CacheEntrySerializer.cs
@@ -93,7 +93,9 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
         // Header count (int)
         // Header(s)
         //   Key (string)
-        //   Value (string)
+        //   ValueCount (int)
+        //   Value(s)
+        //     Value (string)
         // ContainsBody (bool)
         //   Body length (int)
         //   Body (byte[])
@@ -107,8 +109,20 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
             for (var index = 0; index < headerCount; index++)
             {
                 var key = reader.ReadString();
-                var value = reader.ReadString();
-                headers[key] = value;
+                var headerValueCount = reader.ReadInt32();
+                if (headerValueCount > 1)
+                {
+                    var headerValues = new string[headerValueCount];
+                    for (var valueIndex = 0; valueIndex < headerValueCount; valueIndex++)
+                    {
+                        headerValues[valueIndex] = reader.ReadString();
+                    }
+                    headers[key] = headerValues;
+                }
+                else if (headerValueCount == 1)
+                {
+                    headers[key] = reader.ReadString();
+                }
             }
 
             var containsBody = reader.ReadBoolean();
@@ -202,7 +216,11 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
             foreach (var header in entry.Headers)
             {
                 writer.Write(header.Key);
-                writer.Write(header.Value);
+                writer.Write(header.Value.Count);
+                foreach (var headerValue in header.Value)
+                {
+                    writer.Write(headerValue);
+                }
             }
 
             if (entry.Body == null)
diff --git a/test/Microsoft.AspNetCore.ResponseCaching.Tests/CacheEntrySerializerTests.cs b/test/Microsoft.AspNetCore.ResponseCaching.Tests/CacheEntrySerializerTests.cs
index 493906f20b..966fdee6e0 100644
--- a/test/Microsoft.AspNetCore.ResponseCaching.Tests/CacheEntrySerializerTests.cs
+++ b/test/Microsoft.AspNetCore.ResponseCaching.Tests/CacheEntrySerializerTests.cs
@@ -6,6 +6,7 @@ using System.Linq;
 using System.Text;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.ResponseCaching.Internal;
+using Microsoft.Extensions.Primitives;
 using Xunit;
 
 namespace Microsoft.AspNetCore.ResponseCaching.Tests
@@ -76,6 +77,40 @@ namespace Microsoft.AspNetCore.ResponseCaching.Tests
             AssertCachedResponseEqual(cachedResponse, (CachedResponse)CacheEntrySerializer.Deserialize(CacheEntrySerializer.Serialize(cachedResponse)));
         }
 
+        [Fact]
+        public void RoundTrip_CachedResponseWithMultivalueHeaders_Succeeds()
+        {
+            var headers = new HeaderDictionary();
+            headers["keyA"] = new StringValues(new[] { "ValueA", "ValueB" });
+            var cachedResponse = new CachedResponse()
+            {
+                BodyKeyPrefix = FastGuid.NewGuid().IdString,
+                Created = DateTimeOffset.UtcNow,
+                StatusCode = StatusCodes.Status200OK,
+                Body = Encoding.ASCII.GetBytes("Hello world"),
+                Headers = headers
+            };
+
+            AssertCachedResponseEqual(cachedResponse, (CachedResponse)CacheEntrySerializer.Deserialize(CacheEntrySerializer.Serialize(cachedResponse)));
+        }
+
+        [Fact]
+        public void RoundTrip_CachedResponseWithEmptyHeaders_Succeeds()
+        {
+            var headers = new HeaderDictionary();
+            headers["keyA"] = StringValues.Empty;
+            var cachedResponse = new CachedResponse()
+            {
+                BodyKeyPrefix = FastGuid.NewGuid().IdString,
+                Created = DateTimeOffset.UtcNow,
+                StatusCode = StatusCodes.Status200OK,
+                Body = Encoding.ASCII.GetBytes("Hello world"),
+                Headers = headers
+            };
+
+            AssertCachedResponseEqual(cachedResponse, (CachedResponse)CacheEntrySerializer.Deserialize(CacheEntrySerializer.Serialize(cachedResponse)));
+        }
+
         [Fact]
         public void RoundTrip_CachedVaryByRule_EmptyRules_Succeeds()
         {