Theme_Upgrader::current_before( bool|WP_Error $return, array $theme )

Source

File: wp-admin/includes/class-theme-upgrader.php

public function current_before( $return, $theme ) {
		if ( is_wp_error( $return ) ) {
			return $return;
		}

		$theme = isset( $theme['theme'] ) ? $theme['theme'] : '';

		// Only run if current theme
		if ( get_stylesheet() !== $theme ) {
			return $return;
		}

		// Change to maintenance mode. Bulk edit handles this separately.
		if ( ! $this->bulk ) {
			$this->maintenance_mode( true );
		}

		return $return;
	}