SKNode.removeFromParent() EXC_BAD_ACCESS

Question

I noticed a weird behavior in my Swift project and reproduced it on a empty SpriteKit Project that way:

class GameScene: SKScene {
    override func didMoveToView(view: SKView) {

        let sprite = SKSpriteNode(imageNamed:"Spaceship")
        self.addChild(sprite)
        //sprite.removeFromParent()

        let sprite2 = SKSpriteNode(imageNamed:"Spaceship")
        self.addChild(sprite2)
        sprite2.removeFromParent()
    }
}

It crash before the app start and all I can see is this :

My config is xCode6-Beta6, iPad Mini Retina with iOS8-Beta5 and OSX 10.9.4. I also reproduced the bug in the simulators; with xCode6-Beta5; and moving the code in touchesBegan method

Uncommenting the line sprite.removeFromParent() make the bug disappear.

Answer 1

IMPORTANT: this bug has been corrected since iOS 8.1, be sure to update AND make your app unavailable for iOS 8.0 and prior.

I found out what happens... and it should be some Apple employe which did a mistake. Explainations :

let sprite = SKSpriteNode(imageNamed:"Spaceship")
self.addChild(sprite)

let sprite2 = SKSpriteNode(imageNamed:"Spaceship")
self.addChild(sprite2)
sprite2.removeFromParent()

println( sprite == sprite2 ) // Returns "true"
// Then crash

And if you do it :

let sprite = SKSpriteNode(imageNamed:"Spaceship")
sprite.name = "1"
self.addChild(sprite)

let sprite2 = SKSpriteNode(imageNamed:"Spaceship")
sprite2.name = "2"
self.addChild(sprite2)
sprite2.removeFromParent()

println( sprite == sprite2 ) // Returns "false"
// Then all is right, no crash

I think very simply when you call .removeFromParent() Apple's code check for equality in code with == like they would do in Objective-C. But since it's Swift you should do === to check for object equality rather than ==, so a dumb mistake.

Congratz you found a bug in SpriteKit Code, go fill a form at Apple :D