msvcrt: Use Dragon4 algorithm to fix inconsistent rounding behaviour for sprintf and add tests. The Dragon4 algorithm implementation is base http://www.ryanjuckett.com/programming/printing-floating-point-numbers/.

[YongHao Hu]

Good point.
I will have a try.
Thank you for your reply. :)

On 2015年03月30日 19:10, Piotr Caban wrote:
> Hi,
>
> On 03/30/15 10:28, YongHao Hu wrote:
>> Excuse me,
>> Is there anything to do to improve this patch?
> The bug with different rounding can be probably fixed by printing the 
> double with bigger precision and doing the rounding our self. On the 
> other hand there are some advantages of making it not depending on 
> host system standard library.