Multisite: SIte Title is not checked even if it shows that it is required

[alucard001]

In ​http://localhost/wp-admin/network/site-new.php, if we input everything except Site Title, which shows it is required, the process of adding is still going well.

It is because in wp_prepare_site_data() function, the $allowed_data_fields did not contain field "title". You will see that in wp_normalize_site_data(), it contains "title", but later in wp_validate_site_data action, $data did not contain "title", and there is actually no checking on this field.

Please add this title validation back to the process.

Thank you

#54012 adds backend validation for a field that is marked as required in the UI (Site Title in Add New Site screen)

Trac ticket: https://core.trac.wordpress.org/ticket/54012

[jorbin]

In 55894:

Multisite: Require a site title when a site is created

The UI for adding a site says that title is required, however the actual code wasn't requiring it.

Props ideag.
Fixes #54012.

Merged in https://core.trac.wordpress.org/changeset/55894

[kebbet]

@jorbin Please update the milestone to 6.3. Thanks!