"Expects" will falsely match on a class which overrides a collection

[andrewducker]

Given a class:

public class ListWithProperty : List<int>
{
    public string MyProperty { get; set; }
}

I can create two different instances, with different properties, set an expectation for the first one, and then pass in the second one and get the response I'd set up.

        var class1 = MockRepository.GenerateMock<IClass1>();
        var expectedList = new ListWithProperty{MyProperty = "A value"};
        class1.Expect(x => x.GetPropertyFromList(expectedList)).Return("Fake Response");

        var actualList = new ListWithProperty { MyProperty = "A completely different value" };
        var response = class1.GetPropertyFromList(actualList);
        Assert.AreEqual("Fake Response",response);

This is due to the line in Validate.cs RecursiveCollectionEqual
if (expected is ICollection)
Which assumes that if an object is a collection and the items in the collection match then the items are the same. Which is not true in this case.