- Patch #201122 by c960657, Moshe Weitzman: never write anonymous sessions, unless something has been written to . This is an important performance improvements -- as long as you use modules that use  carefully. It might be good to report some analytics about this in the performance settings page so administrators can see if there is a 'broken' module.

- Patch #280934 by pwolanin, swentel, et al: harden session regeneration.  It took a while, but it comes with tests and extra features now.

- Patch #243532 by Damien Tournoud et al: catch notices, warnings and fatal errors during testing.  Woop, woop.