Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web.Extensions/ui/ApplicationServiceManager.cs

@@ -0,0 +1,37 @@
+//------------------------------------------------------------------------------
+// <copyright file="ApplicationServiceManager.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+ 
+namespace System.Web.UI {
+    using System;
+    using System.Web.UI;
+    using System.Web.Resources;
+    using System.Globalization;
+
+    internal static class ApplicationServiceManager {
+        public const int StringBuilderCapacity = 128;
+
+        public static string MergeServiceUrls(string serviceUrl, string existingUrl, Control urlBase) {
+            serviceUrl = serviceUrl.Trim();
+
+            if(serviceUrl.Length > 0) {
+                serviceUrl = urlBase.ResolveClientUrl(serviceUrl);
+
+                if(String.IsNullOrEmpty(existingUrl)) {
+                    // proxy has specified a url and we don't have one yet, so use it
+                    existingUrl = serviceUrl;
+                }
+                else {
+                    // proxy has specified a url but we arleady have a url either from ScriptManager itself or a previous proxy.
+                    // The urls must agree or an exception is thrown.
+                    if(!string.Equals(serviceUrl, existingUrl, StringComparison.OrdinalIgnoreCase)) {
+                        throw new ArgumentException(AtlasWeb.AppService_MultiplePaths);
+                    }
+                }
+            }
+            return existingUrl;
+        }
+    }
+}