Removing dynamically created items from AutopopulatingList

[tboloo]

I have created a simple form for editing user languages. Languages are implemented as AutoPopulatingList, and added dynamically in the jsp using jQuery. Addition works perfectly, but deletion unfortunately not. This is surprising, because when debugging requests I see that serialized form is stripped from removed items, say I start with three languages,

languages[0].code:pl
languages[0].level:Fluent
languages[1].code:de
languages[1].level:Native
languages[2].code:cc
languages[2].level:Intermediate

after removing the middle one POST request is as follows:

languages[0].code:pl
languages[0].level:Fluent
languages[2].code:cc
languages[2].level:Intermediate

but user model retrieved in update method,

@RequestMapping(value = "/user/{id}", method = RequestMethod.POST)
@ResponseBody
public String updateUser(@PathVariable("id") int id, @ModelAttribute("user") User user, HttpServletRequest request) {
    userService.update(user);
    return messageSource.getMessage("user.data_updated", null, request.getLocale());
}

still has three language elements, valid (not nulls, as I would expect in case of deleted items).
I am banging my head agains the wall for quite some time, and I haven't figured out what may be wrong... Any help would be appreciated.
I am using spring 3.1.1 and jQuery 1.7.2 if that's relevant.

[tboloo]

Any ideas?

[zaplitny]

Any ideas?

I guess your request should look like this:

languages[0].code:pl
languages[0].level:Fluent
languages[1].code:cc
languages[1].level:Intermediate