Merge branch '3.1-stable' into develop

Conflicts resolved:
	system/core/CodeIgniter.php
	system/libraries/Email.php
	user_guide_src/source/changelog.rst
	user_guide_src/source/conf.py
	user_guide_src/source/installation/downloads.rst
	user_guide_src/source/installation/upgrading.rst

1 files changed, 19 insertions, 0 deletions

diff --git a/system/libraries/Session/drivers/Session_memcached_driver.php b/system/libraries/Session/drivers/Session_memcached_driver.php
index d9506ba7e..efc084d8b 100644
--- a/system/libraries/Session/drivers/Session_memcached_driver.php
+++ b/system/libraries/Session/drivers/Session_memcached_driver.php
@@ -145,6 +145,8 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 			return $this->_fail();
 		}
 
+		$this->php5_validate_id();
+
 		return $this->_success;
 	}
 
@@ -290,6 +292,23 @@ class CI_Session_memcached_driver extends CI_Session_driver implements SessionHa
 		return $this->_success;
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Validate ID
+	 *
+	 * Checks whether a session ID record exists server-side,
+	 * to enforce session.use_strict_mode.
+	 *
+	 * @param	string	$id
+	 * @return	bool
+	 */
+	public function validateId($id)
+	{
+		$this->_memcached-get($this->_key_prefix.$id);
+		return ($this->_memcached->getResultCode() === Memcached::RES_SUCCESS);
+	}
+
 	// ------------------------------------------------------------------------
 
 	/**