title: Wrong mime type in windows browser for text/csv files
body: <p>I am validating file by checking mime type of file after upload complete.</p>
  
  <p>I am using file object to determine the mime type of file.</p>
  
  <p>This process works very well on Linux and Mac but in windows it shows empty string for text/csv files.</p>
  
  <p>code for reference - </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-html lang-html prettyprint-override"><code>&lt;!DOCTYPE html&gt;
     &lt;html&gt;
     &lt;body&gt;
  
      &lt;input type="file" accept=".csv" onChange="myFunction(event)"&gt;
  
      &lt;script&gt;
         function myFunction(event) {
           console.log(event.target.files[0].type);
           document.write(event.target.files[0].type);
       }
      &lt;/script&gt;
  
     &lt;/body&gt;
    &lt;/html&gt;</code></pre>
  </div>
  </div>
  </p>