1 files changed, 43 insertions, 0 deletions
diff --git a/tests/src/Regressions/coreclr/GitHub_12224/test12224.cs b/tests/src/Regressions/coreclr/GitHub_12224/test12224.cs
new file mode 100644
index 0000000000..8a3124c1b8
--- /dev/null
+++ b/tests/src/Regressions/coreclr/GitHub_12224/test12224.cs
@@ -0,0 +1,43 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+using System;
+using System.Threading;
+
+public class Test12224
+{    
+    // Regression test for EH getting stuck in an infinite loop when NullReferenceException
+    // happens inside a handler of another NullReferenceException.
+    static void ExecuteTest(object context)
+    {
+        string s = null;
+        try
+        {
+            try
+            {
+                int x = s.Length;
+            }
+            catch (NullReferenceException)
+            {
+                int x = s.Length;
+            }
+        }
+        catch (NullReferenceException)
+        {
+
+        }
+    }
+
+    public static int Main()
+    {
+        Thread thread = new Thread(new ParameterizedThreadStart(Test12224.ExecuteTest));
+        thread.IsBackground = true;
+        thread.Start(null);
+
+        // Give the thread 30 seconds to complete (it should be immediate). If it fails
+        // to complete within that timeout, it has hung.
+        bool terminated = thread.Join(new TimeSpan(0, 0, 30));
+
+        return terminated ? 100 : -1;
+    }
+}