[ITK-dev] Bug in the library, or just in the test..?

[Luc Hermitte]

Hi,

Le 23/10/2015 18:43, David Cole via Insight-developers a écrit :
> The itkTransformTest is the only test failing on my Visual Studio 2013
> Debug dashboard because of this code:

What is the exact error produced when your run the test in verbose mode?


> The problem is in the Fill implementation:
> 
>     template< typename TValue >
>     void VariableLengthVector< TValue >
>     ::Fill(TValue const & v) ITK_NOEXCEPT
>     {
>       std::fill_n(&this->m_Data[0], m_NumElements, v);
>     }
> 
> In this test call, m_Data is nullptr, and m_NumElements is 0, so
> clearly,&m_Data[0] is not a useful pointer, and with 0 elements, there
> is nothing to fill.
> 
> So.... should the implementation of Fill be changed to be conditional
> on the pointer being non-nullptr, or the number of elements being
> non-zero, or both? (Are other Fill implementations protected like so?)
> 
> Or should the test be changed to avoid calling Fill when there are no
> elements...?

I'd say that this is a bug in std::fill_n (or something related to the
STL being in CHECKED MODE) and that we should fall back into a plain
loop. We should avoid adding such defensive tests (if (!empty) fill_n()).

I can take care of this issue (only on Monday). If you don't mind, I'd
rather avoid rebasing yet another time and first go through
http://review.source.kitware.com/#/c/20253/10 (I could also fix the
issue I've introduced in my first patch on VLV in this patch, but this
is not the usual patching policy if I understand correctly)


Regards,
-- 
Luc Hermitte