altos/lisp: Check only cdr base type when moving cons cells

The cdr may have moved, so we can't look at the target object
type. Fortunately, the base type encoded in the reference itself is
sufficient to check for a non-cons cdr.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/lisp/ao_lisp_cons.c b/src/lisp/ao_lisp_cons.c
index 06e9d361e65630bf7b35d66ca2fef0eb4416db4e..d3b97383fe655ad9dd28e8ed198445d84fb8307d 100644 (file)
--- a/src/lisp/ao_lisp_cons.c
+++ b/src/lisp/ao_lisp_cons.c
@@ -58,8 +58,8 @@ static void cons_move(void *addr)
                cdr = cons->cdr;
                if (!cdr)
                        break;
-               if (ao_lisp_poly_type(cdr) != AO_LISP_CONS) {
-                       (void) ao_lisp_poly_move(&cons->cdr, 1);
+               if (ao_lisp_poly_base_type(cdr) != AO_LISP_CONS) {
+                       (void) ao_lisp_poly_move(&cons->cdr, 0);
                        break;
                }
                c = ao_lisp_poly_cons(cdr);
@@ -95,8 +95,8 @@ ao_lisp_cons_cons(ao_poly car, ao_poly cdr)
                ao_lisp_poly_stash(0, car);
                ao_lisp_poly_stash(1, cdr);
                cons = ao_lisp_alloc(sizeof (struct ao_lisp_cons));
-               car = ao_lisp_poly_fetch(0);
                cdr = ao_lisp_poly_fetch(1);
+               car = ao_lisp_poly_fetch(0);
                if (!cons)
                        return NULL;
        }