while they return the same layout box (parent), it's more correct to call containingBlock on them.
Created attachment 394866 [details] Patch
Created attachment 394868 [details] Patch
Committed r259181: <https://trac.webkit.org/changeset/259181> All reviewed patches have been landed. Closing bug and clearing flags on attachment 394868 [details].
<rdar://problem/61029530>