add an error check

related to PR 13346
2013-05-01 16:42:45 -05:00 · 2013-05-01 16:42:45 -05:00 · 79e10348b3
commit 79e10348b3
parent 27503c3ae9
1 changed files with 2 additions and 0 deletions
--- a/collects/texpict/private/common-unit.rkt
+++ b/collects/texpict/private/common-unit.rkt
@ -628,6 +628,8 @@
 	(let ([make-superimpose 
 	       (lambda (get-h get-v get-th name)
 		 (lambda boxes
+                   (when (null? boxes)
+                     (error name "expected at least one argument, got none"))
                   (unless (andmap pict? boxes)
                     (error name "expected all picts as arguments, got ~a"
                            (apply string-append (add-between (map (λ (x) (format "~e" x)) boxes) " "))))