8219597: (bf) Heap buffer state changes could provoke unexpected exceptions

[Alan Bateman]

On 27/02/2019 19:36, Brian Burkhalter wrote:
> This issue [1] was instigated by this comment [2]. The change [3] hopefully reduces the exposure of heap buffers to changes in the buffer state, notably the position (cursor).
>
I saw Roger's mail but I think these changes just mean the 
position/limit checked in the preconditions are the values used.  So I 
think the changes are okay. One more to look at is the checkIndex usages 
in the new 2-arg slice method.  A minor nit at L242 where the line break 
makes it harder to read.

-Alan