https://settings-object-worker-client-ckrcsrtdqr.now.sh/ (source at https://settings-object-worker-client-ckrcsrtdqr.now.sh/_src) triggers "SyntaxError: Can't create duplicate variable that shadows a global property: 'c'"
The window has a named property 'c' since I declare an <iframe> with id="c". But then I tried to do `const c = document.querySelector("#c").contentWindow` and got that error.
That error does not appear in other browsers, and I believe has no support in the specs. (Not that window.c is supposed to be configurable.)
Indeed. This is wrong and we already have a bug open to fix it.
*** This bug has been marked as a duplicate of bug 148763 ***