Bug #73302 [Com]: Copy-On-Write on $_SESSION fails with session_decode

Edit report at https://bugs.php.net/bug.php?id=73302&edit=1 ID: 73302 Comment by: x dot huberty at thecodingmachine dot Com Reported by: d dot negrier at thecodingmachine dot com Summary: Copy-On-Write on $_SESSION fails with session_decode Status: Open Type: Bug Package: Session related Operating System: Ubuntu PHP Version: 7.1.0RC3 Block user comment: N Private report: N New Comment: Description: ------------ Bug can seen here: https://3v4l.org/tekjZ We have the same behaviour when we copy a temp variable ($sessionCopy) in $_SESSION. Previous Comments: ------------------------------------------------------------------------ [2016-10-12 13:53:58] d dot negrier at thecodingmachine dot com Description: ------------ Bug can seen here: https://3v4l.org/m1HQ3 It affects all versions starting with 7.0. If I copy the $_SESSION variable in another variable ($sessionCopy) and then I call session_decode, I do not expect $sessionCopy to be impacted by the call to $_SESSION. Yet, in PHP 7.0+, $sessionCopy is also modified. Test script: --------------- <?php session_start(); // $_SESSION is empty so $oldSession is empty too now. // I expect copy to be by value, not by reference so anything impacting $_SESSION should not impace $oldSession. $oldSession = $_SESSION; session_decode('id|i:1;'); var_dump($_SESSION); var_dump($oldSession); Expected result: ---------------- I expect $_SESSION and $oldSession to be different. Actual result: -------------- In PHP 7+, $_SESSION and $oldSession are equal. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=73302&edit=1