Comment 36 for bug 1850651

And more comments from IRC:
20:48:13 - Fallen: I'd recommend to use https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams in the Thunderbird patch
20:50:29 - pmorris has left the room (Quit: Ping timeout: 121 seconds).
20:50:59 - Fallen: Something like let url = new URL(aData); let params = new URLSearchParams((url.search || url.hash).substr(1)); and then use params.get("code") instead of results.code
20:51:29 - Fallen: possibly find out if they are using the hash or the search part of the url and then just use the right thing
20:52:24 - Fallen: Maybe a Cu.importGlobalProperties for URL and/or URLSearchParams