problem: XMLHTTPRequest POSTs blob data to a custom WKURLSchemeHandler protocol will make wkwebview UIProcess crash，The cause of the crash is that the blobRegistry was not initialized Steps: 1、 Setup custom Scheme TestWKURLSchemeHandler *handler = [[TestWKURLSchemeHandler alloc] init]; [configuration setURLSchemeHandler:handler forURLScheme:@"test"]; 2、launch the iOS Simultaor 3、load with url: test://aaa/blobdemo.html ``` <!DOCTYPE html> <html> <head> <title>blob demo</title> </head> <body> <script type="text/javascript"> var blob = new Blob(['blob ', 'foo ', 'bar '], { type: 'plain/text2', endings: 'native' }); var request = new XMLHttpRequest(); request.open("POST", "/testblob"); request.send(blob); </script> </body> </html> ``` 4、Send a *blob* XMLHttpRequest with the custom scheme Result： UIProcess crash
Could you please attach a project that reproduces the issue, and a full crash log?
Created attachment 386811 [details] the crash demo use this demo can reproduct this crash crash log: ``` * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x18) * frame #0: 0x00000001b41a2294 WebCore`WebCore::blobRegistry() + 20 frame #1: 0x00000001b41cd354 WebCore`WebCore::createHTTPBodyCFReadStream(WebCore::FormData&) + 32 frame #2: 0x00000001b41cdd94 WebCore`WebCore::setHTTPBody(_CFURLRequest*, WebCore::FormData*) + 56 frame #3: 0x00000001b316f518 WebCore`WebCore::ResourceRequest::doUpdatePlatformHTTPBody() + 120 frame #4: 0x00000001b41c7284 WebCore`WebCore::ResourceRequestBase::updatePlatformRequest(WebCore::HTTPBodyUpdatePolicy) const + 68 frame #5: 0x00000001b316e0a4 WebCore`WebCore::ResourceRequest::nsURLRequest(WebCore::HTTPBodyUpdatePolicy) const + 20 frame #6: 0x00000001b29efc14 WebKit`WebKit::WebURLSchemeTask::nsRequest() const + 68 frame #7: 0x00000001041d5370 abcd`-[TestWKURLSchemeHandler webView:startURLSchemeTask:](self=0x000000028028c160, _cmd="webView:startURLSchemeTask:", webView=0x000000012801d400, urlSchemeTask=0x00000002800120c0) at ViewController.m:24:24 frame #8: 0x00000001b2996d10 WebKit`WebKit::WebURLSchemeHandlerCocoa::platformStartTask(WebKit::WebPageProxy&, WebKit::WebURLSchemeTask&) + 128 frame #9: 0x00000001b29eec74 WebKit`WebKit::WebURLSchemeHandler::startTask(WebKit::WebPageProxy&, WebKit::WebProcessProxy&, unsigned long long, WebCore::ResourceRequest&&, WTF::CompletionHandler<void (WebCore::ResourceResponse const&, WebCore::ResourceError const&, WTF::Vector<char, 0ul, WTF::CrashOnOverflow, 16ul> const&)>&&) + 220 frame #10: 0x00000001b29bfb90 WebKit`WebKit::WebPageProxy::startURLSchemeTaskShared(WTF::Ref<WebKit::WebProcessProxy, WTF::DumbPtrTraits<WebKit::WebProcessProxy> >&&, WebKit::URLSchemeTaskParameters&&) + 96 frame #11: 0x00000001b29bfaf8 WebKit`WebKit::WebPageProxy::startURLSchemeTask(WebKit::URLSchemeTaskParameters&&) + 52 frame #12: 0x00000001b2c0f30c WebKit`WebKit::WebPageProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 22416 frame #13: 0x00000001b279d0d4 WebKit`IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) + 104 frame #14: 0x00000001b29eb110 WebKit`WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 32 frame #15: 0x00000001b2787b74 WebKit`IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 204 frame #16: 0x00000001b278a9d0 WebKit`IPC::Connection::dispatchIncomingMessages() + 404 frame #17: 0x00000001b9f0389c JavaScriptCore`WTF::RunLoop::performWork() + 276 frame #18: 0x00000001b9f03b5c JavaScriptCore`WTF::RunLoop::performWork(void*) + 36 frame #19: 0x00000001ab158a00 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24 frame #20: 0x00000001ab158958 CoreFoundation`__CFRunLoopDoSource0 + 80 frame #21: 0x00000001ab1580f0 CoreFoundation`__CFRunLoopDoSources0 + 180 frame #22: 0x00000001ab15323c CoreFoundation`__CFRunLoopRun + 1080 frame #23: 0x00000001ab152adc CoreFoundation`CFRunLoopRunSpecific + 464 frame #24: 0x00000001b50d8328 GraphicsServices`GSEventRunModal + 104 frame #25: 0x00000001af24dae0 UIKitCore`UIApplicationMain + 1936 frame #26: 0x00000001041d5d08 abcd`main(argc=1, argv=0x000000016bc2f8f0) at main.m:14:16 frame #27: 0x00000001aafdc360 libdyld.dylib`start + 4 ```
I found that when wkwebview creates the httpbody corresponding to FormData, it will first call the WebCore::blobRegistry method. The return of this method is actually the value of the static variable s_platformStrategies, and this static variable is not initialized, which will cause crash . ``` namespace WebCore { static PlatformStrategies* s_platformStrategies; PlatformStrategies* platformStrategies() { ASSERT(s_platformStrategies); return s_platformStrategies; } void setPlatformStrategies(PlatformStrategies* platformStrategies) { if (!s_platformStrategies) { s_platformStrategies = platformStrategies; return; } // FIXME: This happens when mixing different platform strategies, and we should probably // throw an exception here in release builds. ASSERT(platformStrategies == s_platformStrategies); } } ```
Thanks Mali, I reproed the issue and your understanding is correct. Will fix it.
Uploading blobs to custom scheme handler is not yet supported as per https://bugs.webkit.org/show_bug.cgi?id=197237. The way I was able to repro the crash is to upload XHR with some text and make sure to call xhr.upload so as to set alwaysStream on the FormData.
Created attachment 386822 [details] Patch
Are there any specific plans to support blob data?
(In reply to mali from comment #7) > Are there any specific plans to support blob data? Plan is to fix it but I guess this is probably not a high priority. Any information related to potential use might help bumping the priority.
The commit-queue encountered the following flaky tests while processing attachment 386822 [details]: transitions/default-timing-function.html bug 138901 (authors: dino@apple.com and graouts@apple.com) The commit-queue is continuing to process your patch.
Comment on attachment 386822 [details] Patch Clearing flags on attachment: 386822 Committed r254089: <https://trac.webkit.org/changeset/254089>
All reviewed patches have been landed. Closing bug.
<rdar://problem/58355534>