inline box fragment in the pre-block needs no end values while the inline box fragment in the post-block needs no start values.
Created attachment 448164 [details] Patch
Committed r287514 (245649@main): <https://commits.webkit.org/245649@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 448164 [details].
<rdar://problem/87048385>