ASIHTTP JavacriptCore WTFCrash

Question

My APP use  ASIHTTP request net data.But I got some crash like This. I guess this crash will happen when user set Pac Proxy.

<pre>


    0  JavaScriptCore                 0x18be7f418 WTFCrash + 72
    1  JavaScriptCore                 0x18be7f410 WTFCrash + 64
    2  JavaScriptCore                 0x18bbce2e0 JSC::MachineThreads::addCurrentThread() + 42
    3  JavaScriptCore                 0x18be11434 JSGlobalContextCreateInGroup + 172
    4  CFNetwork                      0x18a587854 CreateJSContextForAutoConfigurationScript + 788
    5  CFNetwork                      0x18a589ad4 PACCacheEntry_ConstructJSContext(void*) + 72
    6  CoreFoundation                 0x18a9a3644 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24
    7  CoreFoundation                 0x18a9a29a0 __CFRunLoopDoSources0 + 256
    8  CoreFoundation                 0x18a9a0c38 __CFRunLoopRun + 632
    9  CoreFoundation                 0x18a8e1c20 CFRunLoopRunSpecific + 452
    10 CFNetwork                      0x18a586f8c CFNetworkCopyProxiesForAutoConfigurationScript + 156
    11 ***                          0x10073d8b0 +[ASIHTTPRequest proxiesForURL:fromPAC:] (ASIHTTPRequest.m:4163)


    </pre>

//The code

    PAC script
    + (NSArray *)proxiesForURL:(NSURL *)theURL fromPAC:(NSURL *)pacScriptURL
    {
        // From: http://developer.apple.com/samplecode/CFProxySupportTool/listing1.html
        // Work around .  This dummy call to 
        // CFNetworkCopyProxiesForURL initialise some state within CFNetwork 
        // that is required by CFNetworkCopyProxiesForAutoConfigurationScript.
        CFRelease(CFNetworkCopyProxiesForURL((CFURLRef)theURL, NULL));


    NSStringEncoding encoding;
    NSError *err = nil;
    NSString *script = [NSString stringWithContentsOfURL:pacScriptURL usedEncoding:&encoding error:&err];
    if (err) {
        // If we can't fetch the PAC, we'll assume no proxies
        // Some people have a PAC configured that is not always available, so I think this is the best behaviour
        return [NSArray array];
    }
    // Obtain the list of proxies by running the autoconfiguration script
    CFErrorRef err2 = NULL;
    NSArray *proxies = NSMakeCollectable([(NSArray *)CFNetworkCopyProxiesForAutoConfigurationScript((CFStringRef)script,(CFURLRef)theURL, &err2) autorelease]);
    if (err2) {
        return nil;
    }
    return proxies;
}

    </pre>