title: Safari blocks JQuery if same Ajax request is fired multiple times
body: <p>This might be a stupid question, but I can't get this to work in Safari (8.0). I have a progress bar which should update automatically while uploading a file. It works perfectly in FF and in Chrome but Safari doesn't update my view. If I got it right, then Safari does not deal with synchronous events, which means the browser blocks every following JQuery. In my opinion this does not matter as one task is finished BEFORE the next one is fired.</p>
  
  <p>Can someone please help me with this? I'm very confused...</p>
  
  <p>Thank you!</p>
  
  <p>I have the following:</p>
  
  <pre><code>// main Ajax call
  function test() {
      $.ajax({
          url : 'getProgressBarPercentage',
          type: 'GET',
          data: 'key=fileUpload',
          async: false,
          success: function(res) {
              console.log(res);   // I do see all values in the console log 
              var percentVal = res + "%";
              $('#pTesting').attr('aria-valuenow', '100').css('width', percentVal); // this only works in Chrome and FF
          },
          error: function(res) {
              console.log('FAIL');
          },
          complete: function(res) { doAgain(); } // if Ajax request is complete ...
      });
  }
  
  // ... fire test() again
  function doAgain() {
      setTimeout(function(){test();},500);
  }
  
  // triggers event after hitting an upload button
  $(document).ready(function () {
      $("#uploadSubmit").click(function () {
            test();
      });
  });
  </code></pre>