Re: [fetch] Allow "manual" redirect fetches with caveats (#66)

We Google Docs/Drive ran into these issues in the following cases:

##### For case 2:  
We have a service worker with scope //docs.google.com/ and one with scope //docs.google.com/spreadsheets/. We have a general //docs.google.com/open?id=... url that can open any item in Google Drive. If the id turns out to be a spreadsheet we send a 302 server side for //docs.google.com/spreadsheets/d/...
Once the page loads it will now be under control of the //docs.google.com/ service worker. 

This means it will miss out on any service worker features that are spreadsheets specific. The workaround with double hitting would also be big issue due to logging, resources and latency for the page load.



##### For case 3:
A user is logged out and hits a service worker controlled endpoint on "docs.google.com". We basically do a fetchEvent.respondWith(fetch(fetchEvent.request)) but catch errors on the fetch so we can fall back to a offline response.

If the user is logged out he gets send to //accounts.google.com to log in. If that happens we show an error and we don't have any clue that this login redirect happened so we can't send a 302 to the page. For this case we haven't really found a good workaround.


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Reply to this email directly or view it on GitHub:
https://github.com/whatwg/fetch/issues/66#issuecomment-112799108