Checkboxes should progress from intermediate state to checked

Thanks to Matt Lundin for pointing that out.

lisp/org-list.el

@@ -2107,8 +2107,8 @@ in subtree, ignoring drawers."
 		 ((equal toggle-presence '(16)) "[-]")
 		 ((equal toggle-presence '(4))
 		  (unless cbox "[ ]"))
-		 ((equal "[ ]" cbox) "[X]")
-		 (t "[ ]"))))))
+		 ((equal "[X]" cbox) "[ ]")
+		 (t "[X]"))))))
       ;; When an item is found within bounds, grab the full list at
       ;; point structure, then: 1. set checkbox of all its items
       ;; within bounds to ref-checkbox; 2. fix checkboxes of the whole

lisp/org.el

@@ -17514,8 +17514,8 @@ This command does many different things, depending on context:
 			       (cond
 				((equal arg '(16)) "[-]")
 				((equal arg '(4)) nil)
-				((equal "[ ]" cbox) "[X]")
-				(t "[ ]")))
+				((equal "[X]" cbox) "[ ]")
+				(t "[X]")))
 	(org-list-struct-fix-ind struct parents)
 	(org-list-struct-fix-bul struct prevs)
 	(setq block-item