From 7b53bdd43e2e605a8eb686f22ceb558f46a1c4f5 Mon Sep 17 00:00:00 2001
From: Kirthi Krishnamraju <kirthik@microsoft.com>
Date: Mon, 14 Sep 2015 10:42:05 -0700
Subject: [PATCH] Fix for #38: Fallback to wrong language preference when the
 top preference is unavailable

---
 ...eptLanguageHeaderRequestCultureProvider.cs |  2 +-
 ...anguageHeaderRequestCultureProviderTest.cs | 64 ++++++++++++++++++-
 2 files changed, 64 insertions(+), 2 deletions(-)

diff --git a/src/Microsoft.AspNet.Localization/AcceptLanguageHeaderRequestCultureProvider.cs b/src/Microsoft.AspNet.Localization/AcceptLanguageHeaderRequestCultureProvider.cs
index 46fbed8cc2..1771f5ada2 100644
--- a/src/Microsoft.AspNet.Localization/AcceptLanguageHeaderRequestCultureProvider.cs
+++ b/src/Microsoft.AspNet.Localization/AcceptLanguageHeaderRequestCultureProvider.cs
@@ -57,7 +57,7 @@ namespace Microsoft.AspNet.Localization
 
                         requestCulture = ValidateRequestCulture(requestCulture);
 
-                        if (requestCulture != null)
+                        if (requestCulture.Culture == culture)
                         {
                             return Task.FromResult(requestCulture);
                         }
diff --git a/test/Microsoft.AspNet.Localization.Tests/AccessLanguageHeaderRequestCultureProviderTest.cs b/test/Microsoft.AspNet.Localization.Tests/AccessLanguageHeaderRequestCultureProviderTest.cs
index b9ccd53707..a93d8f54be 100644
--- a/test/Microsoft.AspNet.Localization.Tests/AccessLanguageHeaderRequestCultureProviderTest.cs
+++ b/test/Microsoft.AspNet.Localization.Tests/AccessLanguageHeaderRequestCultureProviderTest.cs
@@ -16,7 +16,7 @@ namespace Microsoft.Framework.Localization.Tests
     public class AccessLanguageHeaderRequestCultureProviderTest
     {
         [Fact]
-        public async void GetFallbackLanguage()
+        public async void GetFallbackLanguage_ReturnsFirstNonNullCultureFromSupportedCultureList()
         {
             using (var server = TestServer.Create(app =>
             {
@@ -44,5 +44,67 @@ namespace Microsoft.Framework.Localization.Tests
                 var response = await client.GetAsync(string.Empty);
             }
         }
+
+        [Fact]
+        public async void GetFallbackLanguage_ReturnsFromSupportedCulture_AcceptLanguageListContainsSupportedCultures()
+        {
+            using (var server = TestServer.Create(app =>
+            {
+                var options = new RequestLocalizationOptions
+                {
+                    DefaultRequestCulture = new RequestCulture(new CultureInfo("fr-FR")),
+                    SupportedCultures = new List<CultureInfo>
+                    {
+                        new CultureInfo("ar-SA"),
+                        new CultureInfo("en-US")
+                    }
+                };
+                app.UseRequestLocalization(options);
+                app.Run(context =>
+                {
+                    var requestCultureFeature = context.Features.Get<IRequestCultureFeature>();
+                    var requestCulture = requestCultureFeature.RequestCulture;
+                    Assert.Equal("ar-SA", requestCulture.Culture.Name);
+                    return Task.FromResult(0);
+                });
+            }))
+            {
+                var client = server.CreateClient();
+                client.DefaultRequestHeaders.AcceptLanguage.ParseAdd("en-GB,ar-SA,en-US");
+                var count = client.DefaultRequestHeaders.AcceptLanguage.Count;
+                var response = await client.GetAsync(string.Empty);
+            }
+        }
+
+        [Fact]
+        public async void GetFallbackLanguage_ReturnsDefault_AcceptLanguageListDoesnotContainSupportedCultures()
+        {
+            using (var server = TestServer.Create(app =>
+            {
+                var options = new RequestLocalizationOptions
+                {
+                    DefaultRequestCulture = new RequestCulture(new CultureInfo("fr-FR")),
+                    SupportedCultures = new List<CultureInfo>
+                    {
+                        new CultureInfo("ar-SA"),
+                        new CultureInfo("af-ZA")
+                    }
+                };
+                app.UseRequestLocalization(options);
+                app.Run(context =>
+                {
+                    var requestCultureFeature = context.Features.Get<IRequestCultureFeature>();
+                    var requestCulture = requestCultureFeature.RequestCulture;
+                    Assert.Equal("fr-FR", requestCulture.Culture.Name);
+                    return Task.FromResult(0);
+                });
+            }))
+            {
+                var client = server.CreateClient();
+                client.DefaultRequestHeaders.AcceptLanguage.ParseAdd("en-GB,ar-MA,en-US");
+                var count = client.DefaultRequestHeaders.AcceptLanguage.Count;
+                var response = await client.GetAsync(string.Empty);
+            }
+        }
     }
 }
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