Imported Upstream version 4.4.0.40

Former-commit-id: 6427cc082e74df30afc535fd906a3494b74b0817

mcs/tests/test-async-83.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Threading.Tasks;
+
+class MainClass
+{
+	public static int Main ()
+	{
+		var t = GetSomeStrings (null);
+		try {
+			var s = t.Result;
+			return 1;
+		} catch (AggregateException e) {
+			if (e.InnerException is NullReferenceException)
+				return 0;
+
+			return 2;
+		}
+	}
+
+	public static async Task<string> GetSomeStrings (AsyncStringFactory myFactory)
+	{
+		var res = await myFactory?.GetSomeStringAsync ();
+		return res;
+	}
+}
+
+public class AsyncStringFactory
+{
+	public async Task<string> GetSomeStringAsync ()
+	{
+		await Task.Yield();
+		return "foo";
+	}
+}