code: function ShadowAlphaBroken() {
    var cv = NewCanvas(3,3), c, i;
    if(!cv)
      return false;
    c = cv.getContext('2d');
    c.strokeStyle = '#000';
    c.shadowColor = '#fff';
    c.shadowBlur = 3;
    c.globalAlpha = 0;
    c.strokeRect(2,2,2,2);
    c.globalAlpha = 1;
    i = c.getImageData(2,2,1,1);
    cv = null;
    return (i.data[0] > 0);
  }
docs: I think all browsers pass this test now...