wp-includes/ms-functions.php:2146Ensures that the current site's domain is listed in the allowed redirect host list.
$deprecatedarray|stringoptional''string[]$0string
function redirect_this_site( $deprecated = '' ) { return array( get_network()->domain );}Introduced in MU (3.0.0). Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/ms-functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.