added check ala PR 9185

svn: r8647
2008-02-13 17:34:40 +00:00 · 2008-02-13 17:34:40 +00:00 · ff9938a87f
commit ff9938a87f
parent efeb8c7818
1 changed files with 5 additions and 1 deletions
--- a/collects/drscheme/syncheck.ss
+++ b/collects/drscheme/syncheck.ss
@ -447,7 +447,11 @@ If the namespace does not, they are colored the unbound color.
                                        new-vec)
                                       new-vec)))])
                (let loop ([p start])
-                  (when (<= p end)
+                  (when (and (<= p end)
+                             (< p (vector-length arrow-vector))) 
+                    ;; the last test in the above and is because some syntax objects
+                    ;; appear to be from the original source, but can have bogus information.
+                    
                    (let ([r (vector-ref arrow-vector p)])
                      (cond
                        [use-key?