guard use of exn-message

closes PR 13316
2012-11-28 13:16:58 -06:00 · 2012-11-28 13:16:58 -06:00 · 97454b6e55
commit 97454b6e55
parent 253ae42558
1 changed files with 2 additions and 1 deletions
--- a/collects/drracket/private/expanding-place.rkt
+++ b/collects/drracket/private/expanding-place.rkt
@ -204,7 +204,8 @@
                      (andmap (λ (srcloc) (equal? (srcloc-source srcloc) the-source))
                              (exn:fail:read-srclocs exn)))
                 'reader-in-defs-error]
-                [(regexp-match #rx"expand: unbound identifier" (exn-message exn))
+                [(and (exn? exn)
+                      (regexp-match #rx"expand: unbound identifier" (exn-message exn)))
                 'exn:variable]
                [else 'exn])
              (trim-message