Description: bezierCurveTo(cp1x, cp1y, cp2x, cp2y, x, y) must ensure there is a subpath for the point (cp1x,cp1y) if the context has no subpaths, then it must connect the last point in the subpath to the point (x,y).
Test passes if two vertical lines and one curved line are seen below in the shape of a smiley face.