ResourcePointer breaks if you upload the same file twice
As ResourcePointer is no valueobject (for doctrine) anymore, the resource manager creates a second one for the same file, if you upload it twice. Now the sha1 hash is the identifier of the ResourcePointer, and therefore we get a duplicate entry error from the database as we have twice the "same" object.
Updated by Bastian Waidelich about 10 years ago
Note: I think, the correct approach is, to always resend the uploaded file (e.g. it's resource pointer hash) on submit even if it was not changed. Just like other form fields.
This way you can reset the value to an empty string on order to remove an uploaded resource. Needs to be discussed though.