Add a new user to a blog by visiting /newbloguser/username/.
This will only work when the user's details are saved as an option keyed as 'new_user_x', where 'x' is the username of the user to be added, as when a user is invited through the regular WP Add User interface.
The details must at least contain values for the following keys:
<?php maybe_add_existing_user_to_blog(); ?>
This function does not accept parameters, pertinent information is passed by saving it in the options as described in Description. This information is then removed from options once the data has been extracted.
This function does not return. Rather, the thread is terminated with wp_die(), displaying a message indicating success or failure.
maybe_add_existing_user_to_blog() is located in