[Lib2geom-devel] Warning

[Johan E. <jbc...@sw...>]

Hi all,
   Inkscape hits on this warning:

src/2geom/generic-interval.h:65:9: warning: assuming signed overflow 
does not occur when assuming that (X + c) >= X is always true 
[-Wstrict-overflow]

It is caused by this line of code:
    Geom::IntRect area = 
Geom::IntRect::from_xywh(floor(event->button.x), floor(event->button.y), 
1, 1);

Relevant code snippets from our trunk:
generic-rect.h:
     static CRect from_xywh(C x, C y, C w, C h) {
         CPoint xy(x, y);
         CPoint wh(w, h);
         CRect result(xy, xy + wh);
         return result;
     }

generic-interval.h:
     GenericInterval(C u, C v) {
         if (u <= v) {           <------ this is line 65 that triggers 
the warning
             _b[0] = u; _b[1] = v;
         } else {
             _b[0] = v; _b[1] = u;
         }
     }

I believe the warning is valid for the optimization that GCC will 
perform. (actually without optimization, I read that the result is 
undefined when overflow would have occured)
How do we kill that warning?

Thanks,
   Johan