Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/tests/gtest-iter-13.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+class C<T>
+{
+	public IEnumerator GetEnumerator ()
+	{
+		return new T[0].GetEnumerator ();
+	}
+
+	public IEnumerable<T> Filter (Func<T, bool> predicate)
+	{
+		foreach (T item in this)
+			if (predicate (item))
+				yield return item;
+	}
+}
+
+class M
+{
+	public static void Main ()
+	{
+		foreach (var v in new C<long>().Filter(null)) {
+		}
+	}
+}