Open Radar

 
(See https://stackoverflow.com/q/46225247/176304 for a formatted version w/ images)

Summary:

When using batch delete to delete a core data object, the object's external binary data is not deleted.

Steps to Reproduce:

I've set up a simple Core Data project. The data model defines an ImageProperty entity with a binary data attribute that "Allows External Storage".

I don't make any changes to the implementation of the persistentContainer that is provided out-of-the-box:

```swift
lazy var persistentContainer: NSPersistentContainer = {
    let container = NSPersistentContainer(name: "ExternalStorage")
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        ...
    })
    return container
}()
```

On application launch, I create and save an instance of `ImageProperty` with data large enough to be stored externally. I then immediately delete that property using a batch delete:

```swift
let entityName = String(describing: ImageProperty.self)

// Create property

let entity = NSEntityDescription.entity(forEntityName: entityName, in: persistentContainer.viewContext)!
let property = ImageProperty(entity: entity, insertInto: persistentContainer.viewContext)
property.data = NSData(contentsOfFile: Bundle.main.path(forResource: "sample-house-a", ofType: "jpg")!)
try! persistentContainer.viewContext.save()

// Batch-delete property

let fetch: NSFetchRequest  = NSFetchRequest(entityName: entityName)
let request = NSBatchDeleteRequest(fetchRequest: fetch)
_ = try! self.persistentContainer.viewContext.execute(request) as! NSBatchDeleteResult
try! self.persistentContainer.viewContext.save()
```

Expected Results:

The item has been deleted from the database, and the external file has been deleted from the _EXTERNAL_DATA folder.

Actual Results:

The item has been deleted from the database, but the external file has been deleted from the _EXTERNAL_DATA folder.

Version/Build:

iOS 11.0.1 (15A402)

Configuration:

Xcode 9.0 (9A235)
Deployment Target: 11.0
Default "Debug" configuration