**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

}
      if (
        props.checked !== undefined &&
        props.defaultChecked !== undefined &&
        !didWarnCheckedDefaultChecked
      ) {
        warning(
          false,
          '%s contains an input of type %s with both checked and defaultChecked props. ' +
          'Input elements must be either controlled or uncontrolled ' +
          '(specify either the checked prop, or the defaultChecked prop, but not ' +
          'both). Decide between using a controlled or uncontrolled input ' +
          'element and remove one of these props. More info: ' +
          'https://fb.me/react-controlled-components',
          owner && owner.getName() || 'A component',
          props.type
        );
        didWarnCheckedDefaultChecked = true;
      }
      if (
        props.value !== undefined &&
        props.defaultValue !== undefined &&
        !didWarnValueDefaultValue
      ) {
        warning(
          false,
          '%s contains an input of type %s with both value and defaultValue props. ' +
          'Input elements must be either controlled or uncontrolled ' +
          '(specify either the value prop, or the defaultValue prop, but not ' +
          'both). Decide between using a controlled or uncontrolled input ' +