code: protected void doUnlock(HttpServletRequest req, HttpServletResponse resp) {
  
          String path = getRelativePath(req);
  
          // Check if Webdav is read only
          if (m_readOnly) {
  
              resp.setStatus(CmsWebdavStatus.SC_FORBIDDEN);
  
              if (LOG.isDebugEnabled()) {
                  LOG.debug(Messages.get().getBundle().key(Messages.LOG_WEBDAV_READ_ONLY_0));
              }
  
              return;
          }
  
          // Check if resource is locked
          if (isLocked(req)) {
  
              resp.setStatus(CmsWebdavStatus.SC_LOCKED);
  
              if (LOG.isDebugEnabled()) {
                  LOG.debug(Messages.get().getBundle().key(Messages.LOG_ITEM_LOCKED_1, path));
              }
  
              return;
          }
  
          if (LOG.isDebugEnabled()) {
              LOG.debug(Messages.get().getBundle().key(Messages.LOG_UNLOCK_ITEM_0));
          }
  
          m_session.unlock(path);
  
          resp.setStatus(CmsWebdavStatus.SC_NO_CONTENT);
      }
docs: Process a UNLOCK WebDAV request for the specified resource.<p>
  
  @param req the servlet request we are processing
  @param resp the servlet response we are creating