The WebDAV edit attachment link is not generated when URLs are rewritten

## Dav Edit attachment link. We display the link hidden by default, and let the WebDAV JSX extension display it if
      ## the browser supports Dav Edit 
      #set($documentUrl=$doc.getExternalURL("download"))
      #set($attachmentUrl="$documentUrl/$attach.filename")
      #set($attachmentSignature="${request.contextPath}${request.servletPath}/download/")
      #set($webdavSignature="${request.contextPath}/webdav/spaces/")
      #set($fragments=$attachmentUrl.split($attachmentSignature))
      #if($listtool.size($fragments) == 2)
        #set($prefix=$listtool.get($fragments, 0))
        #set($suffix=$listtool.get($fragments, 1))
        #set($davUrl="$prefix$webdavSignature$suffix")
        <a title="$msg.get('core.viewers.attachments.webdavEdit.title')" class="editlink hidden" href="$davUrl" onclick="if(XWiki && XWiki.WebDAV){XWiki.WebDAV.davEdit('$davUrl')}; return false;">$msg.get('core.viewers.attachments.webdavEdit')</a>
      #end