How to retrieve historical events after changes to Domain Event structure

Given event store with fields:

Which contains events based on:

public class OrderLineAdded
{
    int Id;
    short Quantity;
}

... and then has further events added with an updated structure:

public class OrderLineAdded
{
    int ProductId; // field name has changed
    int Quantity; // field datatype has changed
}

When this historical data is retrieved (for analysis, etc), how do you reconstruct binary payload into meaningful data?

Note: the code above is not an example of a good event/event store implementation. I just want to know how this scenario should be handled.

Solution

Rinat Abdullin outlines some domain event versioning strategies in his CQRS bliki that you might find useful to read.

He suggests two possible approaches:

Use a serializer that can cope with renaming of properties in your event automatically such as Google's ProtoBuf Serializer.
Implement the following interface to manually upgrade events in-memory yourself.

public interface IUpgradeDomainEvents
{
    IEnumerable<IDomainEvent> Upgrade(IDomainEvent e, string id);
}