Hi,

2010/4/28 NAKAMURA, Hiroshi <nakahiro / gmail.com>:
> On Wed, Apr 28, 2010 at 21:34, Yusuke Endoh <redmine / ruby-lang.org> wrote:
>>> Do you mean this IO change (multiple pushbacks and behind the
>>> beginning) should be backported to 1.8?
>>
>> I move this ticket to 1.8.
>> But it may be difficult for 1.8 that uses C's stdio to implement IO.
>
> Yes. So I think that the following is not correct.
>
> | ?There is no
> | ?limitation for multiple pushbacks including pushing back behind the
> | ?beginning of the buffer string.


The above spec is valid just for StringIO#ungetc.  It is not directly
connected to IO#ungetc.  Do you mean StringIO#ungetc should behave
the same as IO#ungetc, even in such corner case?

My honest opinion is, this behavior should be considered implementation-
defined, not a spec, not only in 1.8 but also in 1.9.  User should not
depend on such a "corner case" behavior :-)

-- 
Yusuke Endoh <mame / tsg.ne.jp>