Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Web/Util/OrderingMethodFinder.cs

@@ -0,0 +1,31 @@
+using System.Linq.Expressions;
+
+namespace System.Web.Util {
+    internal sealed class OrderingMethodFinder : ExpressionVisitor {
+
+        private bool isTopLevelMethodCall = true;
+
+        private bool OrderingMethodFound {
+            get;
+            set;
+        }
+
+        protected override Expression VisitMethodCall(MethodCallExpression node) {
+            if (isTopLevelMethodCall && QueryableUtility.IsOrderingMethod(node)) {
+                OrderingMethodFound = true;
+            }
+
+            isTopLevelMethodCall = false;
+            Expression result = base.VisitMethodCall(node);
+            isTopLevelMethodCall = true;
+            return result;
+        }
+
+        internal static bool OrderMethodExists(Expression expression) {
+            OrderingMethodFinder obj = new OrderingMethodFinder();
+            obj.OrderingMethodFound = false;
+            obj.Visit(expression);
+            return obj.OrderingMethodFound;
+        }
+    }
+}