Watchlist App Email Notification generates incorrect links when XWiki is deployed as ROOT

In our installation XWiki generates incorrect document links in
notification emails.
It duplicates /bin path element into /bin/bin in every link.

Details:

• XWiki 6.1 (and recently tried 6.4.1 with the same result)
• Tomcat7 container running ROOT.war with XWiki application on
  http://localhost:8080/
• xwiki.cfg contains xwiki.home uncommented and set to a correct public URL
  (https://ourserver.com/)
• Nginx frontend using proxy_pass to serve the public URL

We have also noticed that links to the same pages in emails sent by "Share
by email" extension are correct (no /bin duplication).

See also the mail thread at http://lists.xwiki.org/pipermail/users/2015-February/029983.html

Workaround:

• add a rewrite rule to Nginx config to change /bin/bin/* into /bin/*