From: Jason R Thorpe <thorpej@wasabisystems.com>
> So, really, I'd change _ub to be like this:
> 
> 	union {
> 		struct __sbuf _ubu_ub;
> 		void *_ubu_intcookie;
> 	} _ub_u;
> 
> to really insure that we break compilation of apps that use _ub.

just renaming _ub is enough, isn't it?
(it's what my patch do)

I didn't use union because:
- I worried that compiler makes unnecessary change.
  (padding, re-ordering fields, etc)
- and we will want to use _ub::_size in future.

---
YAMAMOTO Takashi<yamt@mwd.biglobe.ne.jp>