RFR 8240848: ArrayIndexOutOfBoundsException buf for TextCallbackHandler

[Weijun Wang]

Ping again.

> On Mar 12, 2020, at 9:21 PM, Weijun Wang <weijun.wang at oracle.com> wrote:
> 
> Please take a review at
> 
>   http://cr.openjdk.java.net/~weijun/8240848/webrev.00/
> 
> The problem is that selection has a different meaning for a specified optionType (the option value) and an unspecified one (the option index).
> 
> I also take this chance to make ConfirmationCallback more robust.
> 
> Thanks,
> Max
>