$blog_id missing in the newblog_notify_siteadmin filter

[virgodesign]

Hi,
in a wordpress multisite environment there is the newblog_notify_siteadmin( $blog_id, $deprecated ) function that notifies the network admin that a new site has been activated. This function prepare and send the email notice to the network admin just after a news site has been created.

The message is filtered by the newblog_notify_siteadmin hook before the email is sent.

In my opinion this filter does not give a real chance to customize the message because there is no informations passed in about the new created blog.

This is how the filter is

$msg = apply_filters( 'newblog_notify_siteadmin', $msg );

and this is how it should be

$msg = apply_filters( 'newblog_notify_siteadmin', $msg, $blog_id );

This will also create consistency with the

$msg = apply_filters( 'newuser_notify_siteadmin', $msg, $user );

filter, also located in ms-functions.php and related to the new user registration.

[SergeyBiryukov]

In 46697:

Networks and Sites: Pass the $blog_id parameter to the newblog_notify_siteadmin filter.

Props mukto90, virgodesign.
Fixes #48554.

[audrasjb]

Documentation added in the miscellaneous changes dev note: ​https://make.wordpress.org/core/2020/02/26/miscellaneous-developer-focused-changes-in-wordpress-5-4/