[mcs] Add nested types handling to check whether types unify for some type parameter substitutions. Fixes #17647

1 files changed, 12 insertions, 0 deletions

diff --git a/mcs/tests/gtest-604.cs b/mcs/tests/gtest-604.cs
new file mode 100644
index 00000000000..7b142a6c96a
--- /dev/null
+++ b/mcs/tests/gtest-604.cs
@@ -0,0 +1,12 @@
+class A<T>
+{
+	public interface IB { }
+}
+
+class E : A<int>.IB, A<string>.IB
+{
+	public static void Main ()
+	{
+		new E ();
+	}
+}