title: Fabric.js: How to specify selection box secondary border color if the border style is dashed
body: <p>I want to specify a secondary border color on the selection box.</p>
  
  <p>Example why this is needed. If i have two black rectangle, and select one rectangle, some part of the selection border is not visible above the other rectangle:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var canvas = window.__canvas = new fabric.Canvas('canvas');
   
  var rect = new fabric.Rect({left: 10, strokeWidth: 0, top: 10, width: 100, height: 100, fill: 'black'});
   
  var rect2 = new fabric.Rect({left: 40, strokeWidth: 0, top: 60, width: 200, height: 200, fill: 'black'});
   
  rect.cornerSize = 8;
  rect.padding = 0; 
  
  canvas.add(rect);
  canvas.add(rect2);
  canvas.setActiveObject(rect2);  
  
  fabric.Object.prototype.set({
    borderColor: 'black',
    cornerColor: 'black',
    cornerSize: 6,
    transparentCorners: true,
    borderDashArray: [4, 4],
    rotatingPointOffset: 20,
  });</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.js"&gt;&lt;/script&gt;
  
  &lt;canvas id="canvas" width="400" height="400"&gt;&lt;/canvas&gt; </code></pre>
  </div>
  </div>
  </p>