In particular, if I take a Blob and make it iterable and try to create a File from it, the chrome-only ctor will get called (and throw) instead of calling the right constructor... Maybe this is not an issue in practice much, but I would be a lot happier if we used chromeonly factory methods instead of the current chrome-ish constructor setup.
(In reply to Boris Zbarsky [:bz] (TPAC) from comment #0) > Maybe this is not an issue in practice much, but I would be a lot happier if > we used chromeonly factory methods instead of the current chrome-ish > constructor setup. This makes me think P3 but if it's more urgent please change the priority accordingly.
Created attachment 8809759 [details] [diff] [review] boom.patch
Pushed by firstname.lastname@example.org: https://hg.mozilla.org/integration/mozilla-inbound/rev/938f7fd2ce2b Remove the chrome only constructor for File, r=qdot
Could you update the docs: https://developer.mozilla.org/en-US/docs/Extensions/Using_the_DOM_File_API_in_chrome_code
Congrats! Your changes - completed undocumented in FF 52 Release Notes - broke our add-on one more time. It took me several hours to figure out why our add-on is not working in FF 52 Beta anymore. Other add-on authors might be affected too, so please be so kind and update Release Notes accordingly.
Wait, this bug has addon-compat marked. Why did that not result in relevant notes for addon developers?
Though note that general release notes likely wouldn't include something like this anyway except in the general "here's a list of all the changes" way; the "for developers" or addon-developer specific ones might.
It was included in the compat blog post: https://blog.mozilla.org/addons/2016/12/15/compatibility-for-firefox-52/ Not all developers follow it, though, and we didn't do automatic validation for this particular issue.