Check call depth when mrb_yield_class() is called; ref
MODIFY
src/vm.c
src/vm.c
@@ -668,6 +668,9 @@ mrb_yield_with_class(mrb_state *mrb, mrb_value b, mrb_int argc, const mrb_value
if (mrb_nil_p(b)) {
mrb_raise(mrb, E_ARGUMENT_ERROR, "no block given");
}
+ if (mrb->c->ci - mrb->c->cibase > MRB_FUNCALL_DEPTH_MAX) {
+ mrb_exc_raise(mrb, mrb_obj_value(mrb->stack_err));
+ }
p = mrb_proc_ptr(b);
ci = cipush(mrb);
ci->mid = mid;

Check call depth when mrb_yield_class() is called; ref #3521