<!doctype html>
<html>
  <head>
    <title>Drag and drop without cancelling dragenter</title>
    <style type="text/css">
div:first-child {
  height: 100px;
  width: 100px;
  background: orange;
  display: inline-block;
}
div:first-child + div {
  height: 100px;
  width: 100px;
  background: blue;
  display: inline-block;
}
    </style>
    <script type="text/javascript">

window.onload = function () {
  var drag = document.getElementsByTagName('div')[0], sequence = [];
  drag.ondragstart = function (e) {
    e.dataTransfer.setData('text','hello');
    e.dataTransfer.effectAllowed = 'copy';
  };
  drag.ondragenter = drag.ondragover = function (e) {
    e.preventDefault();
  };
  var drop = document.getElementsByTagName('div')[1], dragoverhasfired = false;
  drop.ondragenter = function (e) {
    dragoverhasfired = true; //events targeting body will be ignored until this event has fired
    sequence[sequence.length] = 'drop.dragenter';
  };
  drop.ondragover = function (e) {
    e.preventDefault();
    if( sequence[sequence.length-1] != 'drop.dragover' ) {
      sequence[sequence.length] = 'drop.dragover';
    }
  };
  drop.ondrop = function (e) {
    e.preventDefault();
    sequence[sequence.length] = 'drop.ondrop';
  };
  document.body.ondragenter = function (e) {
    if( e.target != this ) { return; }
    if( dragoverhasfired ) {
      sequence[sequence.length] = 'body.dragenter';
    }
  };
  document.body.ondragover = function (e) {
    if( e.target != this ) { return; }
    if( dragoverhasfired ) {
      if( sequence[sequence.length-1] != 'body.dragover' ) {
        sequence[sequence.length] = 'body.dragover';
      }
    }
  };
  drag.ondragend = function (e) {
    sequence = sequence.join('=&gt;')
    var desiredsequence = (['drop.dragenter','body.dragenter','body.dragover']).join('=&gt;')
    if( sequence == desiredsequence ) {
      document.getElementsByTagName('div')[2].innerHTML = 'PASS';
    } else {
      document.getElementsByTagName('div')[2].innerHTML = 'FAIL, got:<br>'+sequence+'<br>instead of:<br>'+desiredsequence;
    }
  };
};
    </script>
  </head>
  <body>

    <div draggable="true"></div><div></div>
    <div>&nbsp;</div>
    <p>Drag the orange square onto the blue square and release it.</p>
    <noscript><p>Enable JavaScript and reload</p></noscript>

  </body>
</html>
