getControl not handling null values correctly

lib/controls/control.js

@@ -34,7 +34,7 @@ function Control(options) {
 
   this.type = options.type || '';
   this.criticality = options.critical || options.criticality || false;
-  this.value = options.value || undefined;
+  this.value = options.value || null;
 
   var self = this;
   this.__defineGetter__('json', function() {

lib/controls/index.js

@@ -54,7 +54,7 @@ module.exports = {
       control = new Control({
         type: type,
         critical: critical,
-        value: value.toString('utf8')
+        value: value ? value.toString('utf8') : null
       });
     }
 

tst/controls/control.test.js

@@ -58,3 +58,19 @@ test('parse', function(t) {
   t.equal(c.value, 'foo');
   t.end();
 });
+
+
+test('parse no value', function(t) {
+  var ber = new BerWriter();
+  ber.startSequence();
+  ber.writeString('2.16.840.1.113730.3.4.2');
+  ber.endSequence();
+
+  var c = getControl(new BerReader(ber.buffer));
+
+  t.ok(c);
+  t.equal(c.type, '2.16.840.1.113730.3.4.2');
+  t.equal(c.criticality, false);
+  t.notOk(c.value, null);
+  t.end();
+});