A complete example of the failure is here:
Basically lets assume that AProp is property of type IProp, and IProp is an interface:
var superClass1 = new SuperClass
{
Name = Guid.NewGuid().ToString(),
AProp = null
}
No incantation of BsonSerializer.LookupSerializer(); will fix this. Should there be some sort of "NullSerializer" to handle this? Should it just use BsonNullSerializer? Is there a need for a specialized BsonNullInterfacePropertySerializer?
If you don't feel this is by design, I'll file a bug an write a unit test.
Justin