[fixed] Fix rendering Navbar header when toggleNavKey is 0

Fixes react-bootstrap#415

Author: teloo

src/Navbar.jsx

@@ -75,7 +75,7 @@ var Navbar = React.createClass({
     return (
       <ComponentClass {...this.props} className={joinClasses(this.props.className, classSet(classes))}>
         <div className={this.props.fluid ? 'container-fluid' : 'container'}>
-          {(this.props.brand || this.props.toggleButton || this.props.toggleNavKey) ? this.renderHeader() : null}
+          {(this.props.brand || this.props.toggleButton || this.props.toggleNavKey != null) ? this.renderHeader() : null}
           {ValidComponentChildren.map(this.props.children, this.renderChild)}
         </div>
       </ComponentClass>

test/NavbarSpec.jsx

@@ -124,4 +124,30 @@ describe('Nav', function () {
     assert.equal(navNode.nodeName, 'UL');
     assert.equal(navNode.parentNode.nodeName, 'DIV');
   });
+
+  it('Should add header when toggleNavKey is 0', function () {
+    var instance = ReactTestUtils.renderIntoDocument(
+      <Navbar toggleNavKey={0}>
+        <Nav eventKey={0}>
+        </Nav>
+      </Navbar>
+    );
+
+    var header = ReactTestUtils.findRenderedDOMComponentWithClass(instance, 'navbar-header');
+
+    assert.ok(header);
+  });
+
+  it('Should add header when toggleNavKey is 1', function () {
+    var instance = ReactTestUtils.renderIntoDocument(
+      <Navbar toggleNavKey={1}>
+        <Nav eventKey={1}>
+        </Nav>
+      </Navbar>
+    );
+
+    var header = ReactTestUtils.findRenderedDOMComponentWithClass(instance, 'navbar-header');
+
+    assert.ok(header);
+  });
 });