Use JS5's strict mode. But, alas! it outlaws octal! Oh the inanity...

--HG--
branch : testing

common/modules/storage.jsm

@@ -19,6 +19,7 @@
  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  DEALINGS IN THE SOFTWARE.
 }}} ***** END LICENSE BLOCK *****/
+"use strict";
 
 var EXPORTED_SYMBOLS = ["storage", "Timer"];