<div style="width: 0px"><span style="border: solid; word-break: break-word">breakable</span></div>
overflowing run is the inline box start but we can only break at the text run, but the same time we don't want to break between the <span> and its content.
Created attachment 444630 [details]
Committed r286000 (244397@main): <https://commits.webkit.org/244397@main>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 444630 [details].