void Painter::DrawLineStroke(int width, Color color)
{
        Begin();
        LineCap(LINECAP_ROUND);   <<=== Line added
        switch(width) {
                case PEN_NULL:
                        Stroke(0, color);
                        End();
                        return;
                case PEN_SOLID:
                        Stroke(1, color);
                        break;
                case PEN_DASH:
                        Dash("18 6");
                        break;
                case PEN_DOT:
                        Dash("3 3");
                        break;
                case PEN_DASHDOT:
                        Dash("9 6 3 6");
                        break;
                case PEN_DASHDOTDOT:
                        Dash("9 3 3 3 3 3");
                        break;
        default:
                Stroke(width, color);
                End();
                return;
        }
        Stroke(1, color);
        End();
}

void MyClass::Paint(Draw& drw) 
{
	Size sz = GetSize();
	ImageBuffer ib(sz);
	BufferPainter w(ib);	
	w.Clear(RGBAZero());

	w.LineCap(LINECAP_BUTT);		
	
	if (MY_ACTUAL_IMPLEMENTATION) 
		w.DrawLine(0, 0, 20, 20, 5, Black());	// w.LineCap(LINECAP_BUTT) does nothing
	else {			// Proposed implementation
		w.Move(0, 0);
		w.Line(20, 20);
		w.Stroke(5, Black());
	}
	
	drw.DrawImage(0, 0, ib);
}