From 6c99c56018ffc1a1a920a6977b03ad7fac3d4052 Mon Sep 17 00:00:00 2001
From: Marek Safar <marek.safar@gmail.com>
Date: Wed, 5 Feb 2014 15:03:23 +0100
Subject: [PATCH] [corlib] Add nullable tests

---
 mcs/class/corlib/System/Nullable.cs          |  7 ++--
 mcs/class/corlib/Test/System/NullableTest.cs | 44 ++++++++++++++++++++
 mcs/class/corlib/corlib_test.dll.sources     |  1 +
 3 files changed, 48 insertions(+), 4 deletions(-)
 create mode 100644 mcs/class/corlib/Test/System/NullableTest.cs

diff --git a/mcs/class/corlib/System/Nullable.cs b/mcs/class/corlib/System/Nullable.cs
index 86a7bd7d4a4..11f6c67dbd4 100644
--- a/mcs/class/corlib/System/Nullable.cs
+++ b/mcs/class/corlib/System/Nullable.cs
@@ -74,10 +74,9 @@ namespace System
 		{
 			if (nullableType == null)
 				throw new ArgumentNullException ("nullableType");
-			if (nullableType.IsGenericType && nullableType.GetGenericTypeDefinition () == typeof (Nullable<>))
-				return nullableType.GetGenericArguments ()[0];
-			else
-				return null;
+
+			return nullableType.IsGenericType && !nullableType.IsGenericTypeDefinition && nullableType.GetGenericTypeDefinition () == typeof(Nullable<>) ?
+				nullableType.GetGenericArguments () [0] : null;
 		}
 	}
 
diff --git a/mcs/class/corlib/Test/System/NullableTest.cs b/mcs/class/corlib/Test/System/NullableTest.cs
new file mode 100644
index 00000000000..1ec8201e721
--- /dev/null
+++ b/mcs/class/corlib/Test/System/NullableTest.cs
@@ -0,0 +1,44 @@
+//
+// NullableTest.cs
+//
+// Authors:
+//	Marek Safar  <marek.safar@gmail.com>
+//
+// Copyright (C) 2014 Xamarin Inc (http://www.xamarin.com)
+//
+// Permission is hereby granted, free of charge, to any person obtaining
+// a copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to
+// permit persons to whom the Software is furnished to do so, subject to
+// the following conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+
+using System;
+using NUnit.Framework;
+
+namespace MonoTests.System
+{
+	[TestFixture]
+	public class NullableTest
+	{
+		[Test]
+		public void GetUnderlyingType ()
+		{
+			Assert.AreSame (typeof (int), Nullable.GetUnderlyingType (typeof (Nullable<int>)), "#1");
+			Assert.IsNull (Nullable.GetUnderlyingType (typeof (Nullable<>)), "#2");
+		}
+	}
+}
diff --git a/mcs/class/corlib/corlib_test.dll.sources b/mcs/class/corlib/corlib_test.dll.sources
index 5cd15e5de42..e3658887ee4 100644
--- a/mcs/class/corlib/corlib_test.dll.sources
+++ b/mcs/class/corlib/corlib_test.dll.sources
@@ -22,6 +22,7 @@ System/CharEnumeratorTest.cs
 System/CharTest.cs
 System/DelegateTest.cs
 System/ModuleHandleTest.cs
+System/NullableTest.cs
 System/ObsoleteAttributeTest.cs
 System/IntegerTryParse.cs
 System/LazyTest.cs
-- 
2.25.1