NOTE: Use PHP 5.4+ during this test
Preparations:
- don't apply patch yet
- open the Tools → System Tools section in Admin Console in one tab
- open homepage in other tab and confirm, that no error happens
- create an empty trait (in separate file) in the /core/units/users/ folder
- register trait in RegisterClasses array in users_config.php (don't rebuild any caches yet)
- use trait in the UsersEventHandler class
- reload tab with homepage and confirm, that now Fatal Error (related to missing trait) is shown in debugger
Actual test:
- press Deploy button in Tools → System Tools section in Admin Console and confirm, that now Fatal Error (related to missing trait) is shown in debugger
- run do_update script on In-Portal folder and confirm that it ends up with same Fatal Error
- apply patch
- run do_update script and confirm, that no error happens and homepage can be opened after that
- rewind the test to get fatal error again
- press Deploy button in Tools → System Tools section in Admin Console and confirm, that no error happens and homepage can be opened after that