Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel.Web/System/ServiceModel/Configuration/AppSettings.cs

@@ -0,0 +1,78 @@
+// <copyright>
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+
+namespace System.ServiceModel.Web.Configuration
+{
+    using System;
+    using System.Collections.Specialized;
+    using System.Configuration;
+    using System.Diagnostics.CodeAnalysis;
+    using System.Runtime;
+    using System.Security.Permissions;
+
+    internal static class AppSettings
+    {
+        private const string EnableAutomaticEndpointsCompatabilityString = "wcf:webservicehost:enableautomaticendpointscompatability";
+        private const string DisableHtmlErrorPageExceptionHtmlEncodingString = "wcf:web:HtmlErrorPage:DisableExceptionMessageHtmlEncoding";
+        private static readonly object appSettingsLock = new object();
+        private static bool enableAutomaticEndpointCompat = false;
+        private static bool disableHtmlErrorPageExceptionHtmlEncoding = false;
+        private static volatile bool settingsInitialized = false;        
+
+        public static bool EnableAutomaticEndpointsCompatibility
+        {
+            get
+            {
+                EnsureSettingsLoaded();
+                return enableAutomaticEndpointCompat;
+            }
+        }
+
+        public static bool DisableHtmlErrorPageExceptionHtmlEncoding
+        {
+            get
+            {
+                EnsureSettingsLoaded();
+                return disableHtmlErrorPageExceptionHtmlEncoding;
+            }
+        }
+        
+        [SuppressMessage(FxCop.Category.ReliabilityBasic, "Reliability104:CaughtAndHandledExceptionsRule", 
+            Justification = "Handle the configuration exceptions here to avoid regressions on customer's existing scenarios")]
+        private static void EnsureSettingsLoaded()
+        {
+            if (!settingsInitialized)
+            {
+                lock (appSettingsLock)
+                {
+                    if (!settingsInitialized)
+                    {
+                        NameValueCollection appSettingsSection = null;
+                        try
+                        {
+                            appSettingsSection = ConfigurationManager.AppSettings;
+                        }
+                        catch (ConfigurationErrorsException)
+                        {
+                        }
+                        finally
+                        {
+                            if ((appSettingsSection == null) || !bool.TryParse(appSettingsSection[EnableAutomaticEndpointsCompatabilityString], out enableAutomaticEndpointCompat))
+                            {
+                                enableAutomaticEndpointCompat = false;
+                            }
+
+                            if ((appSettingsSection == null) || !bool.TryParse(appSettingsSection[DisableHtmlErrorPageExceptionHtmlEncodingString], out disableHtmlErrorPageExceptionHtmlEncoding))
+                            {
+                                disableHtmlErrorPageExceptionHtmlEncoding = false;
+                            }
+
+                            settingsInitialized = true;
+                        }
+                    }
+                }
+            }
+        }
+    }
+}