Fix #4362
diff --git a/system/libraries/Session/drivers/Session_memcached_driver.php b/system/libraries/Session/drivers/Session_memcached_driver.php
index 760239d..9d7ab11 100644
--- a/system/libraries/Session/drivers/Session_memcached_driver.php
+++ b/system/libraries/Session/drivers/Session_memcached_driver.php
@@ -300,7 +300,10 @@
*/
protected function _get_lock($session_id)
{
- if (isset($this->_lock_key))
+ // PHP 7 reuses the SessionHandler object on regeneration,
+ // so we need to check here if the lock key is for the
+ // correct session ID.
+ if ($this->_lock_key === $this->_key_prefix.$session_id.':lock')
{
return ($this->_memcached->replace($this->_lock_key, time(), 300))
? $this->_success