**Do you want to request a _feature_ or report a _bug_?**

This is a bug (I think)

**What is the current behavior?**

When rendering `<input type="..." />` (without name attribute), it will render `<input type="..." name />` to the DOM.

![2016-07-06 at 09 49](https://cloud.githubusercontent.com/assets/11071/16611205/13bcd376-4360-11e6-9ef5-de6bec6eaa4a.png)

**If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://jsfiddle.net or similar (template: https://jsfiddle.net/reactjs/69z2wepo/).**

Here is the example with the regression using React 15.2.0: https://esnextb.in/?gist=c4923716061ca73e37f7ed476920aa9c

![2016-07-06 at 09 49](https://cloud.githubusercontent.com/assets/11071/16611190/0ba328e8-4360-11e6-8e1a-049048c661f5.png)

**What is the expected behavior?**

No `name` attribute rendered if it is not provided.

Here is the expected behavior with React 15.1.0: https://esnextb.in/?gist=aee86dfa6eec38aa2bc24b4c25425905

![2016-07-06 at 09 54](https://cloud.githubusercontent.com/assets/11071/16611196/10edae9a-4360-11e6-8191-eb19fd9363f8.png)

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**

Regression: v15.2.0

Good: v15.1.0

var nodeValueSetter = jest.genMockFn();
    Object.defineProperty(node, 'value', {
      get: function() {
        return nodeValue;
      },
      set: nodeValueSetter.mockImplementation(function(newValue) {
        nodeValue = newValue;
      }),
    });
    ReactDOM.render(<input value="a" />, container);
    expect(nodeValueSetter.mock.calls.length).toBe(0);
    ReactDOM.render(<input value="b"/>, container);
    expect(nodeValueSetter.mock.calls.length).toBe(1);
  });
  it('should properly control a value of number `0`', function() {
    var stub = <input type="text" value={0} onChange={emptyFunction} />;
    stub = ReactTestUtils.renderIntoDocument(stub);
    var node = ReactDOM.findDOMNode(stub);
    node.value = 'giraffe';
    ReactTestUtils.Simulate.change(node);
    expect(node.value).toBe('0');
  });
  it('should have the correct target value', function() {
    var handled = false;
    var handler = function(event) {
      expect(event.target.nodeName).toBe('INPUT');
      handled = true;
    };
    var stub = <input type="text" value={0} onChange={handler} />;
    var container = document.createElement('div');