From cacd16fa854996af7ea11e3fd61bff9969022845 Mon Sep 17 00:00:00 2001
From: Ben Adams <thundercat@illyriad.co.uk>
Date: Thu, 12 May 2016 20:41:47 +0100
Subject: [PATCH] Remove pragma warning disable 1998

Function doesn't need async
---
 .../Internal/TaskCache.cs                     | 24 +++++++++++++++++++
 .../TagHelpers/TagHelperExecutionContext.cs   |  3 ++-
 .../TagHelpers/TagHelper.cs                   |  6 ++---
 3 files changed, 29 insertions(+), 4 deletions(-)
 create mode 100644 src/Microsoft.AspNetCore.Razor.Runtime/Internal/TaskCache.cs

diff --git a/src/Microsoft.AspNetCore.Razor.Runtime/Internal/TaskCache.cs b/src/Microsoft.AspNetCore.Razor.Runtime/Internal/TaskCache.cs
new file mode 100644
index 0000000000..c10fd7852e
--- /dev/null
+++ b/src/Microsoft.AspNetCore.Razor.Runtime/Internal/TaskCache.cs
@@ -0,0 +1,24 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNetCore.Razor.Internal
+{
+    public static class TaskCache
+    {
+
+        /// <summary>
+        /// A <see cref="Task"/> that's already completed successfully.
+        /// </summary>
+        /// <remarks>
+        /// We're caching this in a static readonly field to make it more inlinable and avoid the volatile lookup done
+        /// by <c>Task.CompletedTask</c>.
+        /// </remarks>
+#if NET451
+        public static readonly Task CompletedTask = Task.FromResult(0);
+#else
+        public static readonly Task CompletedTask = Task.CompletedTask;
+#endif
+    }
+}
\ No newline at end of file
diff --git a/src/Microsoft.AspNetCore.Razor.Runtime/Runtime/TagHelpers/TagHelperExecutionContext.cs b/src/Microsoft.AspNetCore.Razor.Runtime/Runtime/TagHelpers/TagHelperExecutionContext.cs
index aa826dbbd5..fda0854e62 100644
--- a/src/Microsoft.AspNetCore.Razor.Runtime/Runtime/TagHelpers/TagHelperExecutionContext.cs
+++ b/src/Microsoft.AspNetCore.Razor.Runtime/Runtime/TagHelpers/TagHelperExecutionContext.cs
@@ -6,6 +6,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Razor.Internal;
 using Microsoft.AspNetCore.Razor.TagHelpers;
 
 namespace Microsoft.AspNetCore.Razor.Runtime.TagHelpers
@@ -31,7 +32,7 @@ namespace Microsoft.AspNetCore.Razor.Runtime.TagHelpers
                    tagMode,
                    items: new Dictionary<object, object>(),
                    uniqueId: string.Empty,
-                   executeChildContentAsync: async () => await Task.FromResult(result: true),
+                   executeChildContentAsync: () => TaskCache.CompletedTask,
                    startTagHelperWritingScope: _ => { },
                    endTagHelperWritingScope: () => new DefaultTagHelperContent())
         {
diff --git a/src/Microsoft.AspNetCore.Razor.Runtime/TagHelpers/TagHelper.cs b/src/Microsoft.AspNetCore.Razor.Runtime/TagHelpers/TagHelper.cs
index df82eb3797..bd1dd4d4b3 100644
--- a/src/Microsoft.AspNetCore.Razor.Runtime/TagHelpers/TagHelper.cs
+++ b/src/Microsoft.AspNetCore.Razor.Runtime/TagHelpers/TagHelper.cs
@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Razor.Internal;
 
 namespace Microsoft.AspNetCore.Razor.TagHelpers
 {
@@ -37,11 +38,10 @@ namespace Microsoft.AspNetCore.Razor.TagHelpers
         /// <param name="output">A stateful HTML element used to generate an HTML tag.</param>
         /// <returns>A <see cref="Task"/> that on completion updates the <paramref name="output"/>.</returns>
         /// <remarks>By default this calls into <see cref="Process"/>.</remarks>.
-#pragma warning disable 1998
-        public virtual async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
+        public virtual Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
         {
             Process(context, output);
+            return TaskCache.CompletedTask;
         }
-#pragma warning restore 1998
     }
 }
\ No newline at end of file