This bug was filed from the Socorro interface and is report bp-5fe501e7-348d-44d2-bd6e-e51532170111. ============================================================= I think this might be from trying to use ServiceWorkerManager too early or late when the ServiceWorkerRegistrar does not exist.

There are some low frequency crashes that seem to be due to a nullptr registrar. Presumably this is due to triggering ServiceWorkerManager too early or late. Lets gracefully handle these cases instead of crashing.

Pushed by bkelly@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/6bcfde025f6e Gracefully handle ServiceWorkerRegistrar not being active. r=baku

Comment on attachment 8826232 [details] [diff] [review] Gracefully handle ServiceWorkerRegistrar not being active. r=baku Approval Request Comment [Feature/Bug causing the regression]: Service workers [User impact if declined]: Low frequency shutdown and startup crashes. [Is this code covered by automated tests?]: Service workers are heavily tested in automation, but they did not catch this corner case. [Has the fix been verified in Nightly?]: It has not landed on nightly yet, but requesting a bit early to try to get this in for beta RC next week. [Needs manual test from QE? If yes, steps to reproduce]: No [List of other uplifts needed for the feature/fix]: None [Is the change risky?]: Minimal risk [Why is the change risky/not risky?]: This basically checks to see if the ServiceWorkerRegistrar service is nullptr before trying to use it. There is very little risk of regression. [String changes made/needed]:

Comment on attachment 8826232 [details] [diff] [review] Gracefully handle ServiceWorkerRegistrar not being active. r=baku Another crash fix for Service Workers, seems worth the risk for 51 RC.

As usual with stuff that hasn't landed yet on m-c -- if it has to get backed out, please note that here so we can either avoid landing it on aurora/beta, or back it out if needed.