knockout issue #2468

by fastfasterfastest

HTML

<script src="https://knockoutjs.com/downloads/knockout-3.5.0.debug.js"></script>
<select data-bind="options: ['a', b, 'c'], valueAllowUnset: true">
</select>

<button data-bind="click: function(){b(b()==='b' ? 'B' :'b');}">
change b
</button>

JavaScript

(function() {
  ko.options.deferUpdates = true;
  ko.onError = function(error) {
    alert("knockout error\n" + error);
  };

    ko.applyBindings({b:ko.observable("b")});

})();