Merge pull request #94 from erik-kallen/InvokeGenericMethodWithNullableTypeArgument

Invoke generic method with nullable type argument

ICSharpCode.NRefactory.CSharp/Resolver/OverloadResolution.cs

@@ -507,7 +507,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 				if (!ctors.Any())
 					return false;
 			}
-			foreach (IType constraintType in typeParameter.DirectBaseTypes) {
+			foreach (IType constraintType in typeParameter.DirectBaseTypes.Where(tp => !tp.IsKnownType(KnownTypeCode.Object))) {
 				IType c = constraintType;
 				if (substitution != null)
 					c = c.AcceptVisitor(substitution);

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);
+		}
 	}
 }