title: xdg-open not open default browser
body: <p>I have the following scenario:
  Ubuntu 16.04 machine with firefox and chrome installed, chrome being my default browser.</p>
  
  <p>I check this actions in the shell :</p>
  
  <pre><code>cat /usr/share/applications/defaults.list
  cat /etc/mailcap
  cat /.config/mimeapps.list
  cat /.local/share/applications/mimeinfo.cache
  
  x-www-browser-&gt; chrome is launch
  xdg-mime query default text/html
  response:
  google-chrome.desktop
  </code></pre>
  
  <p>And does not appear firefox by any side, always chrome. This is fine. Also check:</p>
  
  <p>Click on a desktop file file.html -> chrome is launch</p>
  
  <p>And now comes the strange, if I run:</p>
  
  <pre><code>xdg-open "http://www.example.com"
  </code></pre>
  
  <p>For some strange reason it always opens firefox. I do not know why, could anyone help me?</p>