List of changes:
* New OOP API using PHP namespace \core\session\.
* All handlers now update the sessions table consistently.
* Experimental DB session support in Oracle.
* Full support for session file handler (filesystem locking required).
* New option for alternative session directory.
* Official memcached session handler support.
* Workaround for memcached version with non-functional gc.
* Improved security - forced session id regeneration.
* Improved compatibility with recent PHP releases.
* Fixed borked CSS during install in debug mode.
* Switched to file based sessions in new installs.
* DB session setting disappears if DB does not support sessions.
* DB session setting disappears if session handler specified in config.php.
* Fast purging of sessions used in request only.
* No legacy distinction - file, database and memcached support the same functionality.
* Session handler name included in performance info.
* Fixed user_loggedin and user_loggedout event triggering.
* Other minor bugfixing and improvements.
* Fixed database session segfault if MUC disposed before $DB.
Limitations:
* Session access time is now updated right after session start.
* Support for $CFG->sessionlockloggedinonly was removed.
* First request does not update userid in sessions table.
* The timeouts may break badly if server hosting forces PHP.ini session settings.
* The session GC is a lot slower, we do not rely on external session timeouts.
* There cannot be any hooks triggered at the session write time.
* File and memcached handlers do not support session lock acquire timeouts.
* Some low level PHP session functions can not be used directly in Moodle code.
Done in a separate commit, coz this driver is not
truly supported, but considering it as a reference
for people developing drivers... it's better to
have it supporting the databasemeta cache.
- added restricting text conditions to where_clause , it throws a dml_exception when detected.
- also added to where_clause throwing dml_exception for field that doesn't exist in table.
- added unit tests for text condition restricting.
- added 2 unit tests for set_field_select() testing 'auto-casting params to int problem' fix
- Include 'pdo' as an extension to be checked for
- Bail out of a connect and throw an exception if the required
extensions aren't loaded
- Don't ignore pdo exceptions on connect error - throw our
own exception
