fixed bug where value is null

Author: matryer

src/arg.js

@@ -146,7 +146,7 @@
           if (!obj.hasOwnProperty(key)) continue;
           var val = obj[key];
 
-          if (typeof(key) === "undefined" || key.length === 0 || typeof(val) === "undefined" || val.length === 0) continue;
+          if (typeof(key) === "undefined" || key.length === 0 || typeof(val) === "undefined" || val === null || val.length === 0) continue;
 
           thisKey = keyPrefix ? keyPrefix+"."+key : key;
 

test/spec/arg.js

@@ -498,7 +498,7 @@ describe("Arg.stringify", function(){
     o["b"] = 1;
     o["c"] = un;
     o["d"] = "";
-    expect(Arg.stringify({"a":o.un,"b":1,"c":o.un,"d":[]})).toEqual("b=1")
+    expect(Arg.stringify({"a":o.un,"b":1,"c":o.un,"d":[],"e":undefined,"f":null})).toEqual("b=1")
   });
 
   it("should ignore keyless values", function(){