iOS崩溃日志栈追踪解析：App Store版内购页面崩溃排查

应用在测试环境（包括TestFlight）中加载内购页面一切正常，但从App Store下载的版本却会崩溃。已获取崩溃日志，但无法区分代码相关部分与底层系统行为。

崩溃栈追踪信息 #

Thread 4 Crashed:
0   My app          0x00000001001b7908 Swift runtime failure: Index out of range + 0 (<compiler-generated>:0)
1   My app          0x00000001001b7908 subscript.get + 20 (<compiler-generated>:0)
2   My app          0x00000001001b7908 specialized Store.productsRequest(_:didReceive:) + 1376
3   My app          0x00000001001b75e8 list.get + 28 (Store.swift:0)
4   My app          0x00000001001b75e8 specialized Store.productsRequest(_:didReceive:) + 576
5   My app          0x00000001001b5d8c productsRequest + 12 (<compiler-generated>:0)
6   My app          0x00000001001b5d8c @objc Store.productsRequest(_:didReceive:) + 76
7   StoreKit                        0x00000001ab0f8070 __27-[SKProductsRequest _start]_block_invoke_2 + 136 (SKProductsRequest.m:104)
8   libdispatch.dylib               0x000000018f5404b4 _dispatch_call_block_and_release + 32 (init.c:1518)
9   libdispatch.dylib               0x000000018f541fdc _dispatch_client_callout + 20 (object.m:560)
10  libdispatch.dylib               0x000000018f5450c8 _dispatch_queue_override_invoke + 788 (inline_internal.h:2632)
11  libdispatch.dylib               0x000000018f553a6c _dispatch_root_queue_drain + 396 (inline_internal.h:0)
12  libdispatch.dylib               0x000000018f554284 _dispatch_worker_thread2 + 164 (queue.c:7052)
13  libsystem_pthread.dylib         0x00000001d49e4dbc _pthread_wqthread + 228 (pthread.c:2631)
14  libsystem_pthread.dylib         0x00000001d49e4b98 start_wqthread + 8

相关函数代码 #

func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
    let myProduct = response.products
    for product in myProduct {
        list.append(product)
    }
    // Update labels
    localTitle = list[0].localizedTitle
    localDescription = list[0].localizedDescription
    
    // Format the price and display
    let formatter = NumberFormatter()
    formatter.locale = Locale.current
    formatter.numberStyle = .currency
    if let formattedPrice = formatter.string(from: list[0].price){
        localPrice = ("Upgrade: \(formattedPrice)")
        delegate?.storeUpdateReceived(store: self)
    }
}

疑问 #

1. 能否定位到函数内具体的崩溃点？还是崩溃发生在进入函数代码之前？
2. Index out of range错误是否由引用list[0]（可能list为空）导致，还是其他索引问题？

崩溃定位 #

从栈追踪可以明确，崩溃发生在Store.productsRequest(_:didReceive:)函数内部，并非进入函数之前。栈帧2、4都指向该函数，结合栈帧0的Index out of range提示和栈帧1的subscript.get，可以确定是访问数组下标时越界触发的错误。

错误原因 #

就是因为直接访问list[0]导致的。测试/TestFlight环境中response.products有数据，但生产环境可能出现以下情况：

• 内购商品ID配置错误（比如生产环境未上架对应商品，或代码中ID与后台配置不一致）
• 用户所在地区受区域限制，无法获取该商品
• StoreKit返回的response.products为空数组

此时list在循环后仍为空，直接访问list[0]就会触发下标越界崩溃。

修复方案 #

在访问list的元素前必须先判断数组是否为空，修改后的代码如下：

func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
    list.removeAll() // 先清空旧数据，避免重复添加
    let myProduct = response.products
    for product in myProduct {
        list.append(product)
    }
    
    // 先判断list是否有有效数据
    guard let firstProduct = list.first else {
        // 处理无商品的情况，比如通知代理加载失败
        delegate?.storeUpdateFailed(error: .noProductsAvailable)
        return
    }
    
    // Update labels
    localTitle = firstProduct.localizedTitle
    localDescription = firstProduct.localizedDescription
    
    // Format the price and display
    let formatter = NumberFormatter()
    formatter.locale = Locale.current
    formatter.numberStyle = .currency
    if let formattedPrice = formatter.string(from: firstProduct.price){
        localPrice = ("Upgrade: \(formattedPrice)")
        delegate?.storeUpdateReceived(store: self)
    }
    
    // 排查无效商品ID，帮助定位配置问题
    if !response.invalidProductIdentifiers.isEmpty {
        print("无效商品ID: \(response.invalidProductIdentifiers)")
        // 可将该信息上报到日志系统
    }
}

内容的提问来源于stack exchange，提问作者laurie