Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/tests/test-iter-23.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections;
+using System.Threading;
+
+class X
+{
+	static ManualResetEvent dispose = new ManualResetEvent (false);
+
+	static IEnumerable GetIt2 ()
+	{
+		yield return Delay ();
+		yield return 2;
+	}
+
+	static int Delay ()
+	{
+		dispose.Set ();
+		Thread.Sleep (10);
+		return 1;
+	}
+
+	public static int Main ()
+	{
+		var e = GetIt2 ().GetEnumerator ();
+		ThreadPool.QueueUserWorkItem (l => {
+			dispose.WaitOne ();
+			((IDisposable) e).Dispose ();
+		});
+
+		if (!e.MoveNext ())
+			return 1;
+
+		if (e.MoveNext ())
+			return 2;
+
+		Console.WriteLine (e.Current);
+		if ((int) e.Current != 1)
+			return 3;
+
+		return 0;
+	}
+}