Use Optional<size_t> for OrderIterator::m_orderIndex instead of int (with invalid value of -1). m_orderIndex a vector index and therefore is in the range of an unsigned (type used internally by Vector, even though the index is exposed as size_t). Therefore, assigning it to an int is unsafe as it may overflow.
This may fix <rdar://problem/23410338> which is a top crasher.
Created attachment 276832 [details]
Comment on attachment 276832 [details]
Clearing flags on attachment: 276832
Committed r199785: <http://trac.webkit.org/changeset/199785>
All reviewed patches have been landed. Closing bug.