Fix 44acd0004

Thanks to Paul Stansell for reporting this.

lisp/org.el

@@ -6890,6 +6890,7 @@ results."
   "Show all headlines in the buffer, like a table of contents.
 With numerical argument N, show content up to level N."
   (interactive "P")
+  (org-overview)
   (save-excursion
     ;; Visit all headings and show their offspring
     (and (integerp arg) (org-overview))