title: Knockout hasFocus binding with number input not working on Firefox
body: <p>I have an input field that holds a currency value. I am trying to display formatted currency amount when the input field does not have focus. The input field type is set to number. While this works fine on Chrome, IE and Edge; on firefox, the input textbox loses focus immediately after getting it. Here is the simplified jsfiddle</p>
  
  <p><a href="https://jsfiddle.net/nkkfmLmc/2/" rel="nofollow">https://jsfiddle.net/nkkfmLmc/2/</a></p>
  
  <p>This is similar to example 2 at <a href="http://knockoutjs.com/documentation/hasfocus-binding.html" rel="nofollow">http://knockoutjs.com/documentation/hasfocus-binding.html</a>, except for the number field. The problem is resolved if I change the input type to text from number (but also lose all the goodness).
  Any pointers or workarounds would be appreciated.</p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;p&gt;
      Name: 
      &lt;b data-bind="visible: !editing(), text: '$'+amount(), click: edit"&gt;&amp;nbsp;&lt;/b&gt;
      &lt;input type="number" min="0" max="100" step="1" data-bind="visible: editing, value: amount, hasFocus: editing" /&gt;
  &lt;/p&gt;
  &lt;p&gt;&lt;em&gt;Click the amount to edit it; click elsewhere to apply changes.&lt;/em&gt;&lt;/p&gt;
  </code></pre>
  
  <p>JS:</p>
  
  <pre><code>function PersonViewModel(amount) {
      // Data
      this.amount = ko.observable(amount);
      this.editing = ko.observable(false);
  
      // Behaviors
      this.edit = function() { this.editing(true) }
  }
  
  ko.applyBindings(new PersonViewModel(51.22));
  </code></pre>