note 120589 added to function.session-start

If you are using a custom session handler via session_set_save_handler() then calling session_start() in PHP 7.1 you might see an error like this: session_start(): Failed to read session data: user (path: /var/lib/php/session) in ... As of this writing, it seems to be happening in PHP 7.1, and things look OK in PHP7.0. It is also hard to track down because if a session already exists for this id (maybe created by an earlier version of PHP), it will not trigger this issue because the $session_data will not be null. The fix is simple... you just need to check for 'null' during your read function: <?php function read($id) { //... pull the data out of the DB, off the disk, memcache, etc $session_data = getSessionDataFromSomewhere($id); //check to see if $session_data is null before returning (CRITICAL) if(is_null($session_data)) { $session_data = ''; //use empty string instead of null! } return $session_data; } ?> ---- Server IP: 72.52.91.14 Probable Submitter: 98.164.64.75 ---- Manual Page -- http://php.net/manual/en/function.session-start.php Edit -- https://master.php.net/note/edit/120589 Del: integrated -- https://master.php.net/note/delete/120589/integrated Del: useless -- https://master.php.net/note/delete/120589/useless Del: bad code -- https://master.php.net/note/delete/120589/bad+code Del: spam -- https://master.php.net/note/delete/120589/spam Del: non-english -- https://master.php.net/note/delete/120589/non-english Del: in docs -- https://master.php.net/note/delete/120589/in+docs Del: other reasons-- https://master.php.net/note/delete/120589 Reject -- https://master.php.net/note/reject/120589 Search -- https://master.php.net/manage/user-notes.php