Improve core_user::fill_properties_cache()

This issue is adding new validation to core user functions to create and update user data, so it must test all types of user data input, from authentication plugins sync scripts, since moodle mobile.

Pre-requisites

1. Install a new instance with this patch applied or clone integration branch.
2. Go through the install paying attention to any debug message or errors.
3. When you reach the point to add your admin user, try to hack and bypass the form validation.
4. Make sure you don't see any error
5. Go to Site administration ► Development ► Debugging
6. Set debug messages to DEVELOPER.
7. Enable debugdisplay.
8. Make sure your PHP config has error_log setted to a valid file.
   • If not setted, add a valid file to be your php error log.

Upload user tool

1. For this test, you might need a CSV file with few users.
2. Edit your CSV file, adding some malicious code to some user fields.
3. - For example firstname - Eric <script>alert(1);</script>Cartman
4. Test other validations changing fields content to something invalid:
   • timezone - Australia_perth
   • lang - ww
   • country - AUSTRALIA
5. Set your default system settings for timezone, lang, country (you can try other settings, calendartype for example)
6. Visit Site administration ► Users ► Accounts ► Upload users
7. Choose your CSV file and click Upload users button.
8. You might see debugging messages for those fields with invalid data in the UI and in your logs, something like this:

   [20-Apr-2016 20:56:52 America/Mexico_City] PHP Notice: The property 'name of the field here' has invalid data and has been cleaned.<ul style="text-align: left" data-rel="backtrace"><li>line 95 of /user/lib.php: call to debugging()</li><li>line 818 of /admin/tool/uploaduser/index.php: call to user_create_user()</li></ul> in /home/moodle/moodles/stable_master/moodle/lib/weblib.php on line 3014

9. It should display a warning for each users that has invalid data on the upload results.
10. Check on the user table, if the user has been added and if the fields with invalid data got cleaned and in case of country and others, it setted the default system setting.
11. Try again, now change you csv file, and add valid user data (valid country, languages..timezones).
    • timezone - America/Mexico City
    • lang - en
    • country - AU
12. You should not see any error or debugging message in your logs.

Webservices

1. Create users using the webservices: core_user_create_users and core_user_update_users
2. Make sure you can create users and the webservice is not broken.
3. Would be nice to extend a bit more and create and update users, using moodle mobile.
4. You should be able to add and update users as expected.

External DB auth plugin.

1. Enable and setup external db plugin.
   • You can simply dump the user table structure and restore in a different database.
2. Add few users to the external db user table.
3. Run the sync: php auth/db/cli/sync_users.php
4. Make sure all users in the external db got created on your moodle user table.
5. Now, change user data accordingly to the upload users tool example.
6. You should get debugging messages and your user invalid data should be cleaned.

LDAP & CAS

1. As CAS uses LDAP user sync, both can be tested at same time.
2. Pretty much the same as above, you should be able to import users without any problem.
   • Invalid data should be displayed in the debugging message.
   • Your users invalid data should be cleaned.

Email auth

1. Enable and setup email authentication.
2. Make sure it works as expected.

PHP Unit and Behat

1. All php unit tests and behat should pass (check nightly results).