Internet Explorer 11/Edge submits form with one input when submit button is disabled on enter, but not with two or more inputs
<p>I don't know if this is a bug or if this behavior is intended, and if it is intended I can't figure out why.  If I have a form with a single input and disabled submit button, in IE11/Edge I can focus the input and hit enter and the form will be submitted.  If there are two inputs, the form is not submitted.</p>

<p>In Firefox and Chrome, this works as I would expect, and the form submit event is not triggered on either example while the button is disabled.</p>

<p><strong>One input (<a href="https://jsfiddle.net/fs13cLa6/" rel="nofollow">jsfiddle</a>)</strong></p>

<p>HTML:</p>

<pre><code>&lt;form&gt;
  &lt;input type="text" id="stuff" /&gt;
  &lt;button type="submit" disabled&gt;submit&lt;/button&gt;
&lt;/form&gt;
</code></pre>

<p>JS:</p>

<pre><code>$('form').on('submit', function() {alert('form submitted');});
$('button').on('click', function() {alert('button clicked');});
$('input').on('input', function() {
    if ($('#stuff').val().trim())
    $('button').prop('disabled', false);
  else
    $('button').prop('disabled', true);
});
</code></pre>

<p><strong>Two inputs (<a href="https://jsfiddle.net/fs13cLa6/4/" rel="nofollow">jsfiddle</a>)</strong></p>

<p>HTML:</p>

<pre><code>&lt;form&gt;
  &lt;input type="text" id="stuff1" /&gt;
  &lt;input type="text" id="stuff2" /&gt;
  &lt;button type="submit" disabled&gt;submit&lt;/button&gt;
&lt;/form&gt;
</code></pre>

<p>JS:</p>

<pre><code>$('form').on('submit', function() {alert('form submitted');});
$('button').on('click', function() {alert('button clicked');});
$('input').on('input', function() {
    if ($('#stuff1').val().trim() &amp;&amp; $('#stuff2').val().trim())
    $('button').prop('disabled', false);
  else
    $('button').prop('disabled', true);
});
</code></pre>

<p>Why does the form with two inputs work correctly in IE11/Edge but not the form with one input?</p>