[whatwg/xhr] Web compat implications of making getAllResponseHeaders lowercase (#146)

Issue #109 changed getAllResponseHeaders to lowercase the values, and we [shipped that in Chrome 60](https://bugs.chromium.org/p/chromium/issues/detail?id=716994). We've had [two reports](https://bugs.chromium.org/p/chromium/issues/detail?id=749086) of serious application breakage (deployed servers that can't just be updated in one place) as a result of this (though we didn't get any such feedback during beta, so it's too late for us to avoid impacting most Chrome users).

@annevk how valuable is it to do this lower casing?  Should we consider reverting to the old behavior given the known web compat impact if we could get consensus from everyone?

@youennf / @cdumez, I see you guys [changed WebKit as well](https://bugs.webkit.org/show_bug.cgi?id=169286). If your users report similar issues how likely are you to revert the change?

I'm still OK doing whatever has browser consensus.  But if other browsers are just going to revert once they feel the compat pain then I'd rather make that decision now for the sake of the impacted Chrome users/developers.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/xhr/issues/146