Test that demonstrates that a generic method cannot be invoked with a nullable type argument.

ICSharpCode.NRefactory.Tests/CSharp/Resolver/InvocationTests.cs

@@ -635,5 +635,53 @@ class Test
 			Assert.AreEqual(OverloadResolutionErrors.MethodConstraintsNotSatisfied, rr.OverloadResolutionErrors);
 			Assert.IsTrue(rr.IsError);
 		}
+
+		[Test]
+		public void MethodCanBeInvokedWithNullableTypeArgument1() {
+			string program = @"
+public class C {
+	static T F<T>() {
+		return default(T);
+	}
+
+	void M() {
+		$F<int?>()$;
+	}
+}";
+
+			var rr = Resolve<CSharpInvocationResolveResult>(program);
+			Assert.IsFalse(rr.IsError);
+		}
+
+		[Test]
+		public void MethodCanBeInvokedWithNullableTypeArgument2() {
+			string program = @"
+public class C {
+	static T F<T>(T t) {
+		return default(T);
+	}
+
+	void M() {
+		$F((int?)null)$;
+	}
+}";
+
+			var rr = Resolve<CSharpInvocationResolveResult>(program);
+			Assert.IsFalse(rr.IsError);
+		}
+
+		[Test]
+		public void CanConstructGenericTypeWithNullableTypeArgument() {
+			string program = @"
+public class X<T> {}
+public class C {
+	void M() {
+		$new X<int?>()$;
+	}
+}";
+
+			var rr = Resolve<CSharpInvocationResolveResult>(program);
+			Assert.IsFalse(rr.IsError);
+		}
 	}
 }