get null inside server

hello .

"Prior to 1.9, an ajax call that expected a return data type of JSON or JSONP would consider a return value of an empty string to be a success case, but return a null to the success handler or promise. As of 1.9, an empty string returned for JSON data is considered to be malformed JSON (because it is); this will now throw an error. Use the error handler to catch such cases." : (jQuery Core 1.9 Upgrade Guide).

but for use this Clue , i must use this code :

			}).error(function(msg){
				1-if(msg.responseText == ""){
					alter("null");
				2-}else{
					alter(msg.responseText);
				}
			});

otherwise (msg.responseText == "") only my solution .

if we use (throw new ApplicationException("X")) and X not accept or other internal error in server , we have(msg.responseText == "").

in this session (msg.responseText == "") not a null result .

please fix it in next version for found Null result .

tanks . (Please forgive me for my English.)