Testing a weak self issue with nested closures reported by @manuelmaly

weakSelfClosureTest.swift

import Foundation
//https://twitter.com/manuelmaly/status/898141485228544000
class Foo {
    var y: Int = 8
    func bar() {
        let b = { [weak self] in
            let x = {
                // self is nil here
                return self?.y
            }()
            print(x)
        }
        return b()
    }
}

let foo = Foo()
foo.bar()