Product Version = NetBeans IDE 7.3 (Build 201302132200)
Operating System = Linux version 3.2.0-41-generic running on amd64
Java; VM; Vendor = 1.7.0_10
Runtime = Java HotSpot(TM) 64-Bit Server VM 23.6-b04

Given the code below, the last "l_err == null" shows this hint: "Unnecessary test for null - the expression is never null".  
This is incorrect, as there a many situations in which l_err will be null.


    String l_err = null;
    if (StringUtil.isEmpty(a_row.optString(DELIVERYDATE))) {
      l_err = "Delivery date missing";
    }
    if (l_err == null && a_row.opt(FLOCKOWNER) == null) {
      l_err = "Flock missing";
    }
    if (l_err == null && StringUtil.isEmpty(a_row.optString(ACTION))) {
      l_err = "Action missing";
    }