From 8a3fdb4b2122ba0fa990fd44ad60eff70c873619 Mon Sep 17 00:00:00 2001
From: Pranav K <prkrishn@hotmail.com>
Date: Sat, 11 May 2019 06:22:19 -0700
Subject: [PATCH] Changes per PR comments

---
 .../CORS/src/Infrastructure/CorsMiddleware.cs     | 15 +++++----------
 .../CORS/src/Infrastructure/CorsOptions.cs        |  4 +++-
 .../Infrastructure/DefaultCorsPolicyProvider.cs   |  3 ++-
 3 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/src/Middleware/CORS/src/Infrastructure/CorsMiddleware.cs b/src/Middleware/CORS/src/Infrastructure/CorsMiddleware.cs
index a8984f472c..d376370cc6 100644
--- a/src/Middleware/CORS/src/Infrastructure/CorsMiddleware.cs
+++ b/src/Middleware/CORS/src/Infrastructure/CorsMiddleware.cs
@@ -125,11 +125,6 @@ namespace Microsoft.AspNetCore.Cors.Infrastructure
                 return _next(context);
             }
 
-            return InvokeCore(context, corsPolicyProvider);
-        }
-
-        private Task InvokeCore(HttpContext context, ICorsPolicyProvider corsPolicyProvider)
-        {
             // CORS policy resolution rules:
             //
             // 1. If there is an endpoint with IDisableCorsAttribute then CORS is not run
@@ -191,12 +186,12 @@ namespace Microsoft.AspNetCore.Cors.Infrastructure
             }
 
             return EvaluateAndApplyPolicy(context, corsPolicy);
-        }
 
-        private async Task InvokeCoreAwaited(HttpContext context, Task<CorsPolicy> policyTask)
-        {
-            var corsPolicy = await policyTask;
-            await EvaluateAndApplyPolicy(context, corsPolicy);
+            async Task InvokeCoreAwaited(HttpContext context, Task<CorsPolicy> policyTask)
+            {
+                var corsPolicy = await policyTask;
+                await EvaluateAndApplyPolicy(context, corsPolicy);
+            }
         }
 
         private Task EvaluateAndApplyPolicy(HttpContext context, CorsPolicy corsPolicy)
diff --git a/src/Middleware/CORS/src/Infrastructure/CorsOptions.cs b/src/Middleware/CORS/src/Infrastructure/CorsOptions.cs
index 5562e47cfd..df32568b07 100644
--- a/src/Middleware/CORS/src/Infrastructure/CorsOptions.cs
+++ b/src/Middleware/CORS/src/Infrastructure/CorsOptions.cs
@@ -14,8 +14,10 @@ namespace Microsoft.AspNetCore.Cors.Infrastructure
     {
         private string _defaultPolicyName = "__DefaultCorsPolicy";
 
+        // DefaultCorsPolicyProvider returns a Task<CorsPolicy>. We'll cache the value to be returned alongside
+        // the actual policy instance to have a separate lookup.
         internal IDictionary<string, (CorsPolicy policy, Task<CorsPolicy> policyTask)> PolicyMap { get; }
-            = new Dictionary<string, (CorsPolicy, Task<CorsPolicy>)>();
+            = new Dictionary<string, (CorsPolicy, Task<CorsPolicy>)>(StringComparer.Ordinal);
 
         public string DefaultPolicyName
         {
diff --git a/src/Middleware/CORS/src/Infrastructure/DefaultCorsPolicyProvider.cs b/src/Middleware/CORS/src/Infrastructure/DefaultCorsPolicyProvider.cs
index 32c3222ef0..e9e5ca9154 100644
--- a/src/Middleware/CORS/src/Infrastructure/DefaultCorsPolicyProvider.cs
+++ b/src/Middleware/CORS/src/Infrastructure/DefaultCorsPolicyProvider.cs
@@ -11,6 +11,7 @@ namespace Microsoft.AspNetCore.Cors.Infrastructure
     /// <inheritdoc />
     public class DefaultCorsPolicyProvider : ICorsPolicyProvider
     {
+        private static readonly Task<CorsPolicy> NullResult = Task.FromResult<CorsPolicy>(null);
         private readonly CorsOptions _options;
 
         /// <summary>
@@ -36,7 +37,7 @@ namespace Microsoft.AspNetCore.Cors.Infrastructure
                 return result.policyTask;
             }
 
-            return Task.FromResult<CorsPolicy>(null);
+            return NullResult;
         }
     }
 }