This turned out to be a chicken/egg "thing" between USU's observer class and main processing class.
When automatic-redirects are enabled, the main class' construction creates the alternate form of the current link's URL and, if different from what's supplied by the access, performs that redirect. If a page (like login) isn't in the list of pages to be handled by USU, the processing calls zen_href_link to create the 'normal' Zen Cart URL.
USU's observer class is (currently) enabling observation for the notification thrown by the zen_href_link function prior to its instantiation of its processing class. That results in a debug-log similar to:
PHP Fatal error: Uncaught Error: Call to a member function href_link() on null in /home/xxx/public_html/includes/classes/observers/UsuObserver.php:52
Restructuring the observer class to instantiate its base class first so that the observer's instance of usu is available for the notification corrects the issue.
This turned out to be a chicken/egg "thing" between USU's observer class and main processing class.
When automatic-redirects are enabled, the main class' construction creates the alternate form of the current link's URL and, if different from what's supplied by the access, performs that redirect. If a page (like
login) isn't in the list of pages to be handled by USU, the processing callszen_href_linkto create the 'normal' Zen Cart URL.USU's observer class is (currently) enabling observation for the notification thrown by the
zen_href_linkfunction prior to its instantiation of its processing class. That results in a debug-log similar to:Restructuring the observer class to instantiate its base class first so that the observer's instance of
usuis available for the notification corrects the issue.