According https://github.com/PWA-POLICE/pwa-bugs#problem-navigation-to-a-website-has-infinite-loading, updating a service worker during a navigation load sometimes trigger terminating a service worker that serves the content for a page, hence making the load fail.
<rdar://problem/46259790>
Seems to indicate that our TryActivate implementation is actually activating the newly installed worker even though there is already an active worker with clients. https://w3c.github.io/ServiceWorker/#try-activate
Our tryActivate implementation does: // Invoke Activate with registration if either of the following is true: // - registration's active worker is null. // - The result of running Service Worker Has No Pending Events with registration's active worker is true, // and no service worker client is using registration or registration's waiting worker's skip waiting flag is set. if (!activeWorker() || (!activeWorker()->hasPendingEvents() && (!hasClientsUsingRegistration() || waitingWorker()->isSkipWaitingFlagSet()))) activate(); So somehow, even though there is an active worker and a pending load handled by that worker, we still call activate().
We are probably registering the new document too late as a service worker client. Currently we are creating/registering the Document when receiving the first data bytes which is too late. Ideally, we should probably register the document as soon as we send the fetch event to the service worker. Another approach would be to keep track of navigation loads a service worker is responsible for and update the activate logic according that new information.
Created attachment 355889 [details] Patch
Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/14286
Comment on attachment 355889 [details] Patch Attachment 355889 [details] did not pass ios-sim-ews (ios-simulator-wk2): Output: https://webkit-queues.webkit.org/results/10185320 New failing tests: imported/w3c/web-platform-tests/webrtc/simplecall-no-ssrcs.https.html media/no-fullscreen-when-hidden.html
Created attachment 355907 [details] Archive of layout-test-results from ews123 for ios-simulator-wk2 The attached test failures were seen while running run-webkit-tests on the ios-sim-ews. Bot: ews123 Port: ios-simulator-wk2 Platform: Mac OS X 10.13.6
Comment on attachment 355907 [details] Archive of layout-test-results from ews123 for ios-simulator-wk2 Error is unrelated
Comment on attachment 355889 [details] Patch Clearing flags on attachment: 355889 Committed r238683: <https://trac.webkit.org/changeset/238683>
All reviewed patches have been landed. Closing bug.