private boolean revert(
      HttpServletRequest request,
      HttpServletResponse response,
      Repository db,
      String commitToRevert)
      throws ServletException, JSONException {
    RevWalk revWalk = new RevWalk(db);
    try {

      Ref headRef = db.getRef(Constants.HEAD);
      if (headRef == null)
        return statusHandler.handleRequest(
            request,
            response,
            new ServerStatus(
                IStatus.ERROR,
                HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
                "An error occured when reverting.",
                null));

      ObjectId objectId = db.resolve(commitToRevert);
      Git git = new Git(db);

      RevertCommand revertCommand = git.revert().include(objectId);
      RevCommit revertedCommit = revertCommand.call();

      if (revertedCommit == null) {
        JSONObject result = new JSONObject();
        result.put(GitConstants.KEY_RESULT, "FAILURE"); // $NON-NLS-1$
        OrionServlet.writeJSONResponse(
            request, response, result, JsonURIUnqualificationStrategy.ALL_NO_GIT);
        return true;
      }

      JSONObject result = new JSONObject();
      result.put(GitConstants.KEY_RESULT, "OK"); // $NON-NLS-1$
      OrionServlet.writeJSONResponse(
          request, response, result, JsonURIUnqualificationStrategy.ALL_NO_GIT);
      return true;
    } catch (IOException e) {
      return statusHandler.handleRequest(
          request,
          response,
          new ServerStatus(
              IStatus.ERROR,
              HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
              "An error occured when reverting.",
              e));
    } catch (GitAPIException e) {
      return statusHandler.handleRequest(
          request,
          response,
          new ServerStatus(
              IStatus.ERROR,
              HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
              "An error occured when reverting.",
              e));
    } finally {
      revWalk.release();
    }
  }