引起NSZombies的Setter（Swift / OBJ-c）

Question

我遇到了一个自动发布问题，我相信行let searchTerm : String = newValue.uppercaseString

有问题的代码是由obj-c调用的快速代码。

当我删除uppercaseString代码时，我的软件似乎没有发生任何不好的事情，而当它的内容变得混乱时。有什么东西明显我错过了吗？像@synchronized电话或其他什么？

///Section 3.5.1.11 - Consist of 8 Characters 0-9 and A-Z and Space - truncates trailing spaces
    var callsign: String {
        get {

            let callsignArray: [UInt8] = [bytes[19], bytes[20], bytes[21], bytes[22], bytes[23], bytes[24], bytes[25], bytes[26]]
            let callsignString = NSString(bytes: callsignArray, length: callsignArray.count, encoding: NSUTF8StringEncoding)
            let ret =  callsignString! as! String
            return ret.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
    }
        set {

            // Make string uppercase
            let searchTerm : String = newValue.uppercaseString

            // Scan for invalid characters
            let regex = NSRegularExpression(pattern: "[^A-Z0-9 ].*", options: nil, error: nil)!
            if regex.firstMatchInString(searchTerm, options: nil, range: NSMakeRange(0, count(searchTerm))) != nil {
                NSException(name:"name", reason:"Invalid character past into Callsign", userInfo:nil).raise()
            } else {
                println("No special characters")
            }

            var acid: String = searchTerm;

            // Truncate to length


            while (count(acid) < 8) {
                acid = acid + [" "]
            }

            // Assign only 8 characters to string
            let buf = [UInt8](acid.utf8)
            for (var i = 0; i <= 7; i++) {
                    bytes[19 + i] = buf[i]
            }
        }
    }
}