Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

external/aspnetwebstack/src/System.Web.Mvc/ExpressionUtil/DefaultExpressionFingerprint.cs

@@ -0,0 +1,30 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
+
+using System.Diagnostics.CodeAnalysis;
+using System.Linq.Expressions;
+
+#pragma warning disable 659 // overrides AddToHashCodeCombiner instead
+
+namespace System.Web.Mvc.ExpressionUtil
+{
+    // DefaultExpression fingerprint class
+    // Expression of form default(T)
+
+    [SuppressMessage("Microsoft.Usage", "CA2218:OverrideGetHashCodeOnOverridingEquals", Justification = "Overrides AddToHashCodeCombiner() instead.")]
+    internal sealed class DefaultExpressionFingerprint : ExpressionFingerprint
+    {
+        public DefaultExpressionFingerprint(ExpressionType nodeType, Type type)
+            : base(nodeType, type)
+        {
+            // There are no properties on DefaultExpression that are worth including in
+            // the fingerprint.
+        }
+
+        public override bool Equals(object obj)
+        {
+            DefaultExpressionFingerprint other = obj as DefaultExpressionFingerprint;
+            return (other != null)
+                   && this.Equals(other);
+        }
+    }
+}