Fix generational-GC bug in struct code.

* struct.c (static_slot_ensure): In the case when we grow the
array of static slots, we were allowing chk_manage_vec to
initialize the newly added element. This is wrong, because
it is just a plain assignment, which causes a mature object
to point to a baby object. This bug caused static slots to
contain junk.

1 files changed, 5 insertions, 3 deletions

diff --git a/struct.c b/struct.c
index 2cda3cbd..7cfdee24 100644
--- a/struct.c
+++ b/struct.c
@@ -819,12 +819,14 @@ val static_slot_ensure(val stype, val sym, val newval, val no_error_p)
     st->eqmslot = 0;
 
   if (nullocp((ptr = lookup_static_slot(stype, st, sym)))) {
+    val null_ptr = 0;
     if (!memq(sym, st->slots)) {
       st->stslot = coerce(val *, chk_manage_vec(coerce(mem_t *, st->stslot),
                                                 st->nstslots, st->nstslots + 1,
                                                 sizeof (val),
-                                                coerce(mem_t *, &newval)));
+                                                coerce(mem_t *, &null_ptr)));
       set(mkloc(st->slots, stype), append2(st->slots, cons(sym, nil)));
+      ptr = mkloc(st->stslot[st->nstslots], stype);
       sethash(slot_hash, cons(sym, num_fast(st->id)),
               num(st->nstslots++ + STATIC_SLOT_BASE));
     } else {
@@ -832,10 +834,10 @@ val static_slot_ensure(val stype, val sym, val newval, val no_error_p)
         uw_throwf(error_s, lit("~a: ~s is an instance slot of ~s"),
                   self, sym, stype, nao);
     }
-  } else {
-    set(ptr, newval);
   }
 
+  set(ptr, newval);
+
   {
     val iter;
     for (iter = st->dvtypes; iter; iter = cdr(iter))