Fix issue #63 - "Paper radio button names that evaluate to false can be deselected without allow-empty-selection"

paper-radio-group.html

@@ -132,24 +132,27 @@
         return;
       }
 
-      if (this.selected) {
+      if ( (this.selected !== undefined) && (this.selected !== null)) {
         var oldItem = this._valueToItem(this.selected);
 
-        if (this.selected == value) {
+        if (this.selected === value) {
           // If deselecting is allowed we'll have to apply an empty selection.
           // Otherwise, we should force the selection to stay and make this
           // action a no-op.
           if (this.allowEmptySelection) {
             value = '';
           } else {
-            if (oldItem)
+            if (oldItem) {
               oldItem.checked = true;
+            }
+
             return;
           }
         }
 
-        if (oldItem)
+        if (oldItem) {
           oldItem.checked = false;
+        }
       }
 
       Polymer.IronSelectableBehavior.select.apply(this, [value]);

test/basic.html

@@ -42,6 +42,15 @@
       </template>
     </test-fixture>
 
+    <test-fixture id="WithFalsyValueSelection">
+      <template>
+        <paper-radio-group required selected="">
+          <paper-radio-button name="">No</paper-radio-button>
+          <paper-radio-button name="a_value">Yes</paper-radio-button>
+        </paper-radio-group>
+      </template>
+    </test-fixture>
+
     <test-fixture id="WithDisabled">
       <template>
         <paper-radio-group selected="r1">
@@ -192,6 +201,28 @@
           }, 1);
         });
 
+        test('clicking the selected item should not deselect with falsy values', function (done) {
+          var g = fixture('WithFalsyValueSelection');
+          MockInteractions.focus(g);
+
+          // Needs to be async since the underlying iron-selector uses observeNodes.
+          Polymer.Base.async(function() {
+            var items = g.items;
+
+            expect(items[0].checked).to.be.equal(true);
+
+            // The selection should not change, but wait for a little bit just
+            // in case it would and an event would be fired.
+            setTimeout(function() {
+              expect(items[0].checked).to.be.equal(true);
+              expect(items[1].checked).to.be.equal(false);
+              done();
+            }, 1);
+
+            MockInteractions.tap(items[0]);
+          }, 1);
+        });
+
         test('clicking the selected item should deselect if allow-empty-selection is set', function (done) {
           var g = fixture('WithSelection');
           g.allowEmptySelection = true;