Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Xml/System/Xml/XPath/Internal/ParentQuery.cs

@@ -0,0 +1,40 @@
+//------------------------------------------------------------------------------
+// <copyright file="ParentQuery.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+// <owner current="true" primary="true">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace MS.Internal.Xml.XPath {
+    using System;
+    using System.Xml;
+    using System.Xml.XPath;
+    using System.Diagnostics;
+    using System.Globalization;
+    using System.Collections.Generic;
+
+    internal sealed class ParentQuery : CacheAxisQuery {
+
+        public ParentQuery(Query  qyInput, string Name, string Prefix, XPathNodeType Type) : base(qyInput, Name, Prefix, Type) {}
+        private ParentQuery(ParentQuery other) : base(other) { }
+
+        public override object Evaluate(XPathNodeIterator context) {
+            base.Evaluate(context);
+
+            // 
+            XPathNavigator input;
+            while ((input = qyInput.Advance()) != null) {
+                input = input.Clone();
+
+                if (input.MoveToParent()) {
+                    if (matches(input)) {
+                        Insert(outputBuffer, input);
+                    }
+                }
+            }
+            return this;
+        }
+
+        public override XPathNodeIterator Clone() { return new ParentQuery(this); }        
+    }
+}