crash on cart page (cart.html)

1. user has already selected few item on cart. 
2. click on update quantity will see the crash. It works only when the radio 
button is being chosen.

org.springframework.web.util.NestedServletException: Request processing failed; 
nested exception is java.lang.NumberFormatException: null
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:583)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:511)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
    at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:224)
    at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:126)

Original issue reported on code.google.com by lhkh...@gmail.com on 28 Feb 2011 at 3:40

Merged into: #98

MHL3060 / bentux

crash on cart page (cart.html) #97