wp-includes/widgets/class-wp-widget-block.php:225Makes sure no block widget is considered to be wide.
$is_widebool$widget_idstringbool public function set_is_wide_widget_in_customizer( $is_wide, $widget_id ) { if ( str_starts_with( $widget_id, 'block-' ) ) { return false; } return $is_wide; }Introduced in 5.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/widgets/class-wp-widget-block.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.