Guard some unsafe ops.

2015-11-03 14:32:23 -06:00 · 2015-11-03 14:32:23 -06:00 · 5b57736af6
commit 5b57736af6
parent 59b5cb7346
1 changed files with 1 additions and 1 deletions
--- a/typed-racket-lib/typed-racket/types/current-seen.rkt
+++ b/typed-racket-lib/typed-racket/types/current-seen.rkt
@ -24,5 +24,5 @@
      A))
 (define (seen? ss st cs)
  (for/or ([i (in-list cs)])
-    (and (eq? ss (unsafe-car i)) (eq? st (unsafe-cdr i)))))
+    (and (pair? i) (eq? ss (unsafe-car i)) (eq? st (unsafe-cdr i)))))