Edited Issue: PropertyGrid native array support crashes (NullReferenceException) [20885]

PropertyGrid has no correct handling code for arrays (only Lists); inserting an object with an embedded c# array causes a crash after editing the collection (when an element is added, for instance).

To reproduce:
class TestSubclass
{
public string m_test1;
public string Test1
{
get { return m_test1; }
set { m_test1 = value; }
}
public string m_test2;
public string Test2
{
get { return m_test2; }
set { m_test2 = value; }
}
}

class TestObject
{
TestSubclass[] m_array;
public TestSubclass[] Array
{
get { return m_array; }
set { m_array = value; }
}
}

public MainWindow()
{
InitializeComponent();
propGrid.SelectedObject = new TestObject();
}