From 7d3d700300c54ec7779474b372cfff5a27c49a46 Mon Sep 17 00:00:00 2001
From: Alex Shinn <ashinn@users.noreply.github.com>
Date: Sat, 19 Jan 2013 01:30:49 +0900
Subject: [PATCH] adding type check to lookup-type

---
 sexp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sexp.c b/sexp.c
index 63bcebc8..50404345 100644
--- a/sexp.c
+++ b/sexp.c
@@ -332,7 +332,9 @@ sexp sexp_register_simple_type_op (sexp ctx, sexp self, sexp_sint_t n, sexp name
 sexp sexp_lookup_type_op(sexp ctx, sexp self, sexp_sint_t n, sexp name, sexp id) {
   int i;
   sexp res;
-  const char* str = sexp_string_data(name);
+  const char* str;
+  sexp_assert_type(ctx, sexp_stringp, SEXP_STRING, name);
+  str = sexp_string_data(name);
   if (sexp_fixnump(id)) {
     i = sexp_unbox_fixnum(id);
     if (i < sexp_context_num_types(ctx)