wp-includes/ms-functions.php:2467Formats a URL to use https.
$urlstringstringfunction filter_SSL( $url ) { // phpcs:ignore WordPress.NamingConventions.ValidFunctionName.FunctionNameInvalid if ( ! is_string( $url ) ) { return get_bloginfo( 'url' ); // Return home site URL with proper scheme. } if ( force_ssl_content() && is_ssl() ) { $url = set_url_scheme( $url, 'https' ); } return $url;}Introduced in 2.8.5. 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.