[Fixes #5637] Make CookieName of CookieTempDataProvider configurable

src/Microsoft.AspNetCore.Mvc.ViewFeatures/CookieTempDataProviderOptions.cs

@@ -22,5 +22,10 @@ namespace Microsoft.AspNetCore.Mvc
         /// The domain set on a cookie. Defaults to <c>null</c>.
         /// </summary>
         public string Domain { get; set; }
+
+        /// <summary>
+        /// The name of the cookie which stores TempData. Defaults to <see cref="CookieTempDataProvider.CookieName"/>. 
+        /// </summary>
+        public string CookieName { get; set; } = CookieTempDataProvider.CookieName;
     }
 }

src/Microsoft.AspNetCore.Mvc.ViewFeatures/ViewFeatures/CookieTempDataProvider.cs

@@ -23,14 +23,14 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
         private readonly IDataProtector _dataProtector;
         private readonly TempDataSerializer _tempDataSerializer;
         private readonly ChunkingCookieManager _chunkingCookieManager;
-        private readonly IOptions<CookieTempDataProviderOptions> _options;
+        private readonly CookieTempDataProviderOptions _options;
 
         public CookieTempDataProvider(IDataProtectionProvider dataProtectionProvider, IOptions<CookieTempDataProviderOptions> options)
         {
             _dataProtector = dataProtectionProvider.CreateProtector(Purpose);
             _tempDataSerializer = new TempDataSerializer();
             _chunkingCookieManager = new ChunkingCookieManager();
-            _options = options;
+            _options = options.Value;
         }
 
         public IDictionary<string, object> LoadTempData(HttpContext context)
@@ -40,9 +40,9 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
                 throw new ArgumentNullException(nameof(context));
             }
 
-            if (context.Request.Cookies.ContainsKey(CookieName))
+            if (context.Request.Cookies.ContainsKey(_options.CookieName))
             {
-                var encodedValue = _chunkingCookieManager.GetRequestCookie(context, CookieName);
+                var encodedValue = _chunkingCookieManager.GetRequestCookie(context, _options.CookieName);
                 if (!string.IsNullOrEmpty(encodedValue))
                 {
                     var protectedData = Base64UrlTextEncoder.Decode(encodedValue);
@@ -63,7 +63,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
 
             var cookieOptions = new CookieOptions()
             {
-                Domain = string.IsNullOrEmpty(_options.Value.Domain) ? null : _options.Value.Domain,
+                Domain = string.IsNullOrEmpty(_options.Domain) ? null : _options.Domain,
                 HttpOnly = true,
                 Secure = context.Request.IsHttps,
             };
@@ -75,19 +75,19 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
                 var bytes = _tempDataSerializer.Serialize(values);
                 bytes = _dataProtector.Protect(bytes);
                 var encodedValue = Base64UrlTextEncoder.Encode(bytes);
-                _chunkingCookieManager.AppendResponseCookie(context, CookieName, encodedValue, cookieOptions);
+                _chunkingCookieManager.AppendResponseCookie(context, _options.CookieName, encodedValue, cookieOptions);
             }
             else
             {
-                _chunkingCookieManager.DeleteCookie(context, CookieName, cookieOptions);
+                _chunkingCookieManager.DeleteCookie(context, _options.CookieName, cookieOptions);
             }
         }
 
         private void SetCookiePath(HttpContext httpContext, CookieOptions cookieOptions)
         {
-            if (!string.IsNullOrEmpty(_options.Value.Path))
+            if (!string.IsNullOrEmpty(_options.Path))
             {
-                cookieOptions.Path = _options.Value.Path;
+                cookieOptions.Path = _options.Path;
             }
             else
             {

test/Microsoft.AspNetCore.Mvc.ViewFeatures.Test/ViewFeatures/CookieTempDataProviderTest.cs

@@ -6,9 +6,9 @@ using System.Collections;
 using System.Collections.Generic;
 using Microsoft.AspNetCore.DataProtection;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.WebUtilities;
 using Microsoft.AspNetCore.Http.Internal;
 using Microsoft.AspNetCore.Mvc.ViewFeatures.Internal;
+using Microsoft.AspNetCore.WebUtilities;
 using Microsoft.Extensions.Options;
 using Moq;
 using Xunit;
@@ -17,6 +17,41 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
 {
     public class CookieTempDataProviderTest
     {
+        [Fact]
+        public void SaveTempData_UsesCookieName_FromOptions()
+        {
+            // Arrange
+            var exepectedCookieName = "TestCookieName";
+            var values = new Dictionary<string, object>();
+            values.Add("int", 10);
+
+            var tempDataProviderStore = new TempDataSerializer();
+            var expectedDataToProtect = tempDataProviderStore.Serialize(values);
+            var expectedDataInCookie = Base64UrlTextEncoder.Encode(expectedDataToProtect);
+            var tempDataProvider = GetProvider(dataProtector: null, options: new CookieTempDataProviderOptions()
+            {
+                CookieName = exepectedCookieName
+            });
+
+            var responseCookies = new MockResponseCookieCollection();
+            var httpContext = new Mock<HttpContext>();
+            httpContext
+                .SetupGet(hc => hc.Request.PathBase)
+                .Returns("/");
+            httpContext
+                .Setup(hc => hc.Response.Cookies)
+                .Returns(responseCookies);
+
+            // Act
+            tempDataProvider.SaveTempData(httpContext.Object, values);
+
+            // Assert
+            Assert.Contains(responseCookies, (cookie) => cookie.Key == exepectedCookieName);
+            var cookieInfo = responseCookies[exepectedCookieName];
+            Assert.Equal(expectedDataInCookie, cookieInfo.Value);
+            Assert.Equal("/", cookieInfo.Options.Path);
+        }
+
         [Fact]
         public void LoadTempData_ReturnsEmptyDictionary_WhenNoCookieDataIsAvailable()
         {
@@ -583,11 +618,11 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
 
         private CookieTempDataProvider GetProvider(IDataProtector dataProtector = null, CookieTempDataProviderOptions options = null)
         {
-            if(dataProtector == null)
+            if (dataProtector == null)
             {
                 dataProtector = new PassThroughDataProtector();
             }
-            if(options == null)
+            if (options == null)
             {
                 options = new CookieTempDataProviderOptions();
             }