Fix bug

src/libraries/System.Private.CoreLib/src/System/AppContext.AnyOS.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Diagnostics.Tracing;
 using System.IO;
@@ -51,7 +52,6 @@ internal static void LogSwitchValues(RuntimeEventSource ev)
             {
                 lock (s_dataStore)
                 {
-                    var dataStore = s_dataStore;
                     if (s_switches is not null)
                     {
                         lock (s_switches)
@@ -66,10 +66,11 @@ internal static void LogSwitchValues(RuntimeEventSource ev)
 
                     void LogDataStore(Dictionary<string, bool>? switches)
                     {
-                        foreach (var (k, v) in dataStore)
+                        Debug.Assert(s_dataStore is not null);
+                        foreach (var (k, v) in s_dataStore)
                         {
                             if (v is string s && bool.TryParse(s, out bool isEnabled) &&
-                                switches?.ContainsKey(s) != true)
+                                switches?.ContainsKey(k) != true)
                             {
                                 ev.LogAppContextSwitch(k, isEnabled ? 1 : 0);
                             }

src/tests/tracing/runtimeeventsource/RuntimeEventSourceTest.cs

@@ -16,7 +16,7 @@
 AppDomain.CurrentDomain.SetData("appContextBoolData", true); // Not loggeed, bool key
 AppDomain.CurrentDomain.SetData("appContextBoolAsStringData", "true");
 AppDomain.CurrentDomain.SetData("appContextStringData", "myString"); // Not logged, string does not parse as bool
-AppDomain.CurrentDomain.SetData("appContextSwitch", false); // should not override the SetSwitch above
+AppDomain.CurrentDomain.SetData("appContextSwitch", "false"); // should not override the SetSwitch above
 
 // Create an EventListener.
 using (var myListener = new RuntimeEventListener())