make OUString::copy() clip

[Michael Stahl]

On 01/08/12 19:05, Eike Rathke wrote:
> Hi Stephan,
> 
> On Wednesday, 2012-08-01 18:17:12 +0200, Stephan Bergmann wrote:
> 
>> make rtl::OUString::copy(beginIndex, count) clip to [0..length)?
>> yeah, why not  (then again, -1's sentinel nature, cf. indexOf, might
>> mean that silent clipping of beginIndex=-1 to beginIndex=0 is
>> unfortunate)
> 
> We may step into more of these traps in transitions from String to
> OUString, so clipping IMHO is good.
> 
> I think beginIndex<0 or count<=0 should always return an empty string
> and output a SAL_WARN, maybe also SAL_WARN if clipping occurred as that
> may indicate a logic error.

no, it should assert().  passing in invalid indexes is clearly a bug
that must be fixed.