                ;; All fits in a single row.
                (values 1 nil))
               (t
-               (lusty--compute-optimal-layout-inner lengths-v)))
+               (lusty--compute-optimal-layout-inner lengths-v
+                                                    separator-length)))
       (let ((n-columns 0)
             (column-widths '()))
 

(defvar lusty--ignored-extensions-regex nil)
(defvar lusty--highlighted-index 0)
(defvar lusty--previous-printed-matches '())

(when lusty--wrapping-ido-p
  (require 'ido))

      (let ((col-start-index 0)
            (col-end-index (1- n-rows))
            (total-width 0)
            (split-factor (aref lusty--greatest-factors n-rows)))

        ;; Calculate required total-width for this number of rows.
        (while (>= col-end-index n-items)
          (let ((column-width
                 (lusty--compute-column-width
                  col-start-index col-end-index split-factor
