double free in Chapter 9

[ajarara]

lval_del(y) is called twice here, in the case of a division by 0 error:

  while (a->count > 0) {

    /* Pop the next element */
    lval* y = lval_pop(a, 0);

    if (strcmp(op, "+") == 0) { x->num += y->num; }
    if (strcmp(op, "-") == 0) { x->num -= y->num; }
    if (strcmp(op, "*") == 0) { x->num *= y->num; }
    if (strcmp(op, "/") == 0) {
      if (y->num == 0) {
        lval_del(x); lval_del(y);
        x = lval_err("Division By Zero!"); break;
      }
      x->num /= y->num;
    }

    lval_del(y);
  }

[ajarara]

Ah, nevermind! Missed the break statement. Closing