c.toArray might (incorrectly) not return Object[] (see 6260652)

[Doug Lea]

David Holmes - Sun Microsystems wrote:
> Thanks for the info, one query though ...
> 
> Ummm why didn't it just use:
> 
>     elementData = c.toArray(new Object[c.size()]);
> 

Because "c" might be a concurrent collection, so you
don't want to independently call c.size(). Notice
that AbstractCollection correctly implements
toArray() even for such collections but cannot do so
for toArray(T[] a) because it must interpret
a.length as the required size.

-Doug