On Thursday 31 October 2002 6:02 am, Rob Lahaye wrote: > Hi, > > The attached patch fixes an image clipping bug in > xformsImage.C. The patch fixes the following type of error: > > int i = 5; > unsigned int ui = 20; > int offset = std::max(0U, i - ui); > > Here, (i - ui) is converted to unsigned int. > If (i - ui) is negative, then this is converted to a very > large unsigned number and thus the std::max returns the > unsigned int (i - ui). This is finally converted to a normal > int, which becomes negative. In the above example, offset does > not become zero, but -15 !!!! > > I discovered this error,when flimage_clip() crashed with > negative offset values (although all offsets where calculated > with std::max). After my patch, the crash disappeared. > > > Please have a look at the attached patch and apply if OK. > > Regards, > Rob.
Thanks, Rob. Applied. Angus
