Entity Framework 6 - use my getHashCode()

It’s interesting and surprising that you got your application working this way in EF5. EF always requires only a single instance of any entity. If a graph of objects are added and EF incorrectly assumes that it is already tracking an object when it is in fact tracking a different instance, then the internal state that EF is tracking will be inconsistent. For example, the graph just uses .NET references and collections, so the graph will still have multiple instances, but EF will only be tracking one instance. This means that changes to properties of an entity may not be detected correctly and fixup between instances may also result in unexpected behavior. It would be interesting to know if your code solved these problems in some way or if it just so happened that your app didn’t hit any of these issues and hence the invalid state tracking didn’t matter for your app.

The change we made for EF6 makes it less likely that an app can get EF state tracking into an invalid state which would then cause unexpected behavior. If you have a clever pattern to ensure the tracking state is valid that we broke with EF6 then it would be great if you could file a bug with a full repro at http://entityframework.codeplex.com/.