Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/errors/cs0278-2.cs

@@ -0,0 +1,30 @@
+// CS0278: `IListCounter' contains ambiguous implementation of `enumerable' pattern. Method `IList.GetEnumerator()' is ambiguous with method `ICounter.GetEnumerator()'
+// Line: 26
+// Compiler options: -warnaserror -warn:2
+
+using System;
+using System.Collections;
+
+interface IList 
+{
+	IEnumerator GetEnumerator ();
+}
+
+interface ICounter 
+{
+	IEnumerator GetEnumerator ();
+}
+
+interface IListCounter: IList, ICounter
+{
+}
+
+class Test
+{
+	static void Foo (IListCounter t)
+	{
+		foreach (var e in t)
+		{
+		}
+	}
+}