iOS scaling bug fix

// iOS scaling bug fix
// Rewritten version
// By @mathias, @cheeaun and @jdalton
// Source url: https://gist.github.com/901295
(function(doc) {
    var addEvent = 'addEventListener',
    type = 'gesturestart',
    qsa = 'querySelectorAll',
    scales = [1, 1],
    meta = qsa in doc ? doc[qsa]('meta[name=viewport]') : [];
    function fix() {
        meta.content = 'width=device-width,minimum-scale=' + scales[0] + ',maximum-scale=' + scales[1];
        doc.removeEventListener(type, fix, true);
    }
    if ((meta = meta[meta.length - 1]) && addEvent in doc) {
        fix();
        scales = [0.25, 1.6];
        doc[addEvent](type, fix, true);
    }
}(document));