1. Make a test script like <?php require_once('config.php'); context_helper::build_all_paths(true); echo 'done'; run it, and verify that there are no errors. 2. Change the 'true' to 'false', and run the script again. 3. Go in to the context table, find two rows with contextlevel = 30 (user). In one set depth to 0, and in the other set path to NULL. Run the 'false' version of the test script again. Make sure it sets the data back to the correct values. 4. Again, edit rows in the user table, but set depth to something silly, like 100, and path to a random string. Run the 'true' version of the test script again. Make sure it sets the data back to the correct values.