Re: [PATCH 0/1] MR3936: gdiplus/tests: add tests of InterpolationMode Bilinear for GdipDrawImagePointsRect

[Jeffrey Smith (＠whydoubt)]

Jeffrey Smith (@whydoubt) commented about dlls/gdiplus/tests/image.c:
>  }
>
> }
>
> +INT compare_with_precision(const void *ptr1, const void *ptr2, size_t num, INT precision)
> +{
> - if (ptr1 == NULL || ptr2 == NULL)
> - return ptr1 < ptr2 ? -1 : 1;
> -
> - for (size_t i = 0; i < num; i++)
> - {
> - unsigned char byte1 = *((unsigned char *)ptr1 + i);
> - unsigned char byte2 = *((unsigned char *)ptr2 + i);
> -
> - if ((byte1 < byte2 - precision) || (byte1 > byte2 + precision))

I believe the operations here could over/under-flow.  Seems like that may cause problems.