From b8a8393a027474d1a8bde2ec9590a1b91bcec184 Mon Sep 17 00:00:00 2001
From: Alex Shinn <ashinn@users.noreply.github.com>
Date: Sun, 30 Oct 2011 23:35:58 +0900
Subject: [PATCH] convert nulls to void on generic slot-ref

---
 vm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/vm.c b/vm.c
index 92f5673c..50eed250 100644
--- a/vm.c
+++ b/vm.c
@@ -1354,6 +1354,7 @@ sexp sexp_apply (sexp ctx, sexp proc, sexp args) {
       sexp_raise("slot-ref: not an integer", sexp_list1(ctx, _ARG3));
     _ARG3 = sexp_slot_ref(_ARG2, sexp_unbox_fixnum(_ARG3));
     top-=2;
+    if (!_ARG1) _ARG1 = SEXP_VOID;
     break;
   case SEXP_OP_SLOTN_SET:
     if (! sexp_typep(_ARG1))