The function calls the map of the vector when it is empty and tries to use the result, refactor it to make it clear that in this situation it is empty.
Created attachment 451731 [details] Patch
Committed r289731 (247216@main): <https://commits.webkit.org/247216@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 451731 [details].
<rdar://problem/88899147>