On pages where admins typically end at after logging in, moodle performs moodle_needs_upgrading() call to see if a database upgrade is needed. These pages include index.php, admin/index.php, and my/index.php. The check helps to avoid the situation when the site is used in the unstable state of mismatch between the code and the datanbase version.

The page admin/search.php has not been executing that check, yet it is used as the default Site administration page. So even if administrators follow the good old instruction "follow the Site administration link", no upgrade was actually triggered unless they explicitly visit the Notification page.

In MDL-60167, marina showed that this can easily lead to serious problems with data integrity. We should not leave the site unattended in the middle of the upgrade and we can help this by putting the page admin/search.php into the list of pages where we execute the upgrade check. It should behave same as my/index.php