WP_Upgrader::move_to_temp_backup_dir( string[] $args )

	public function move_to_temp_backup_dir( $args ) {
		global $wp_filesystem;

		if ( empty( $args['slug'] ) || empty( $args['src'] ) || empty( $args['dir'] ) ) {
			return false;
		}

		/*
		 * Skip any plugin that has "." as its slug.
		 * A slug of "." will result in a `$src` value ending in a period.
		 *
		 * On Windows, this will cause the 'plugins' folder to be moved,
		 * and will cause a failure when attempting to call `mkdir()`.
		 */
		if ( '.' === $args['slug'] ) {
			return false;
		}

		if ( ! $wp_filesystem->wp_content_dir() ) {
			return new WP_Error( 'fs_no_content_dir', $this->strings['fs_no_content_dir'] );
		}

		$dest_dir = $wp_filesystem->wp_content_dir() . 'upgrade-temp-backup/';
		$sub_dir  = $dest_dir . $args['dir'] . '/';

		// Create the temporary backup directory if it does not exist.
		if ( ! $wp_filesystem->is_dir( $sub_dir ) ) {
			if ( ! $wp_filesystem->is_dir( $dest_dir ) ) {
				$wp_filesystem->mkdir( $dest_dir, FS_CHMOD_DIR );
			}

			if ( ! $wp_filesystem->mkdir( $sub_dir, FS_CHMOD_DIR ) ) {
				// Could not create the backup directory.
				return new WP_Error( 'fs_temp_backup_mkdir', $this->strings['temp_backup_mkdir_failed'] );
			}
		}

		$src_dir = $wp_filesystem->find_folder( $args['src'] );
		$src     = trailingslashit( $src_dir ) . $args['slug'];
		$dest    = $dest_dir . trailingslashit( $args['dir'] ) . $args['slug'];

		// Delete the temporary backup directory if it already exists.
		if ( $wp_filesystem->is_dir( $dest ) ) {
			$wp_filesystem->delete( $dest, true );
		}

		// Move to the temporary backup directory.
		$result = move_dir( $src, $dest, true );
		if ( is_wp_error( $result ) ) {
			return new WP_Error( 'fs_temp_backup_move', $this->strings['temp_backup_move_failed'] );
		}

		return true;
	}