When a custom element constructor invokes HTMLElement constructor of a different realm, WebKit uses that realm's HTMLElement to construct the element instead of HTMLElement in new.target's realm.
Created attachment 347244 [details] Fixes the bug
<rdar://problem/43365966>
Attachment 347244 [details] did not pass style-queue: ERROR: Source/WebCore/ChangeLog:14: Line contains tab character. [whitespace/tab] [5] Total errors found: 1 in 4 files If any of these errors are false positives, please file a bug against check-webkit-style.
Created attachment 347245 [details] Fixed the change log
Comment on attachment 347245 [details] Fixed the change log r=me.
Comment on attachment 347245 [details] Fixed the change log Thanks for the review!
Comment on attachment 347245 [details] Fixed the change log Clearing flags on attachment: 347245 Committed r234957: <https://trac.webkit.org/changeset/234957>
All reviewed patches have been landed. Closing bug.