title: What is the "iPhone viewport scale bug"?
body: <p><a href="http://html5boilerplate.com/mobile" rel="nofollow">HTML5 mobile boilerplate</a> recommends adding this snippet of Javascript to fix the "iPhone viewport scale bug":</p>
  
  <pre><code>// Fix for iPhone viewport scale bug 
  // http://www.blog.highub.com/mobile-2/a-fix-for-iphone-viewport-scale-bug/
  
  MBP.viewportmeta = document.querySelector &amp;&amp; document.querySelector('meta[name="viewport"]');
  MBP.ua = navigator.userAgent;
  
  MBP.scaleFix = function () {
    if (MBP.viewportmeta &amp;&amp; /iPhone|iPad|iPod/.test(MBP.ua) &amp;&amp; !/Opera Mini/.test(MBP.ua)) {
      MBP.viewportmeta.content = "width=device-width, minimum-scale=1.0, maximum-scale=1.0";
      document.addEventListener("gesturestart", MBP.gestureStart, false);
    }
  };
  MBP.gestureStart = function () {
      MBP.viewportmeta.content = "width=device-width, minimum-scale=0.25, maximum-scale=1.6";
  };
  </code></pre>
  
  <ul>
  <li>What is the "iPhone viewport scale bug"? (The linked blog post doesn't make sense to me)</li>
  <li>How does this code go about fixing the bug? (I.e., what exactly does it do?)</li>
  </ul>