wp-includes/widgets.php:1579Compares a list of sidebars with their widgets against an allowed list.
$sidebars_widgetsarray$allowed_widget_idsarrayoptionalarray()arrayfunction _wp_remove_unregistered_widgets( $sidebars_widgets, $allowed_widget_ids = array() ) { if ( empty( $allowed_widget_ids ) ) { $allowed_widget_ids = array_keys( $GLOBALS['wp_registered_widgets'] ); } foreach ( $sidebars_widgets as $sidebar => $widgets ) { if ( is_array( $widgets ) ) { $sidebars_widgets[ $sidebar ] = array_intersect( $widgets, $allowed_widget_ids ); } } return $sidebars_widgets;}Introduced in 4.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/widgets.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.