Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/tests/gtest-448.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+
+interface I<T> : I2<T>, IEnumerable<T>
+{
+}
+
+interface I2<T2>
+{
+	void Foo<U> (IEnumerable<U> list) where U : T2;
+}
+
+class Impl<T> : I<T>
+{
+	public void Foo<U> (IEnumerable<U> list) where U : T
+	{
+	}
+	
+	public IEnumerator<T> GetEnumerator ()
+	{
+		return null;
+	}
+	
+	System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator ()
+	{
+		return null;
+	}
+}
+
+class A<K>
+{
+	public I<K> Value = new Impl<K> ();
+}
+
+class Test<TT> : A<TT>
+{
+	public void Foo ()
+	{
+		var a = new Test<TT> ();
+		a.Value.Foo (Value);
+	}
+}
+
+class M 
+{
+	public static void Main ()
+	{
+		new Test<ulong> ().Foo ();
+	}
+}
+