[Toybox] dd tests for transaction size?

[Rob Landley]

On 07/10/2017 02:00 PM, enh wrote:
> On Mon, Jul 10, 2017 at 10:57 AM, enh <enh at google.com> wrote:
>>> Would the above bs= behavior tie sound like it would work for the users
>>> you found?
>>
>> for what the comments claim, yes, but i'll track one of the clueful
>> users down and check with them...
> 
> actually, only one user seems to be setting bs=. everyone else has ibs=.

Any idea why?

Right now bs= is already behaving specially for the last block (posix!)
so adding another aspect to the existing special case makes sense. But
if I make that change, setting ibs= instead of bs= is what you'd do to
_preserve_ the posix behavior. :)

Rob