Worker's creation URL is set before worker global scope's url is set

[hiroshige-g]

In https://html.spec.whatwg.org/#set-up-a-worker-environment-settings-object,
Step 7 sets settings object's creation URL to worker global scope's url at the time of #set-up-a-worker-environment-settings-object (i.e. Step 9 of https://html.spec.whatwg.org/#run-a-worker).

However, at that time, worker global scope's url is not yet set (which will be set in Step 13's custom fetch steps' Step 3).

Before [1], the creation URL was worker global scope's url at the time of referencing creation URL (which is assumed after worker global scope's url is set) and thus was response's URL.

[1] 2b93f9e

Should creation URL still be the response URL of the top-level worker script?
Or should it be something else?

@jungkees as the author of [1], @nhiroki for workers.

[wanderview]

Based on the discussion in w3c/ServiceWorker#1034 we intended for the worker Client.url (creation URL) to be the empty string until execution ready. Then it should be set to the final response URL.