Internet Bug Bounty: Out-of-bounds reads in zif_grapheme_stripos with negative offset

https://bugs.php.net/bug.php?id=72061 graphemestripos from the intl extension had a security issue when handling negative offsets, this allowed to read from arbitrary memory locations. Reported to developers on 2016-04-24, fixed 2016-04-29 and released at 2016-04-28, affected PHP 5.5 , 5.6 and 7...