Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/tests/gtest-515.cs

@@ -0,0 +1,38 @@
+using System;
+
+interface I<T>
+{
+}
+
+class A
+{
+	public virtual I<T> Foo<T> () where T : IDisposable
+	{
+		return null;
+	}
+}
+
+class AA : A
+{
+	public override I<V> Foo<V> ()
+	{
+		return base.Foo<V> ();
+	}
+}
+
+class B : AA, IDisposable
+{
+	public void Dispose ()
+	{
+	}
+	
+	public override I<R> Foo<R> ()
+	{
+		return base.Foo<R> ();
+	}
+	
+	public static void Main ()
+	{
+		new B ().Foo<B> ();
+	}
+}