assertField() is broken

After the rash of commits tonight, assertField() fails because:

function assertField($id, $message = '') {
$this->assertFieldByXPath($this->_constructFieldXpath('name', $name) .'|'. $this->_constructFieldXpath('id', $id), '', $message);
}

$name isn't passed into the function.

Patch should be credited to chx, who told me how to fix it.