Autocomplete: Normalization should handle null values

[johan-ludvigsson-stratsys]

In the _normalize function the following is returned:

return $.extend({
    label: item.label || item.value,
    value: item.value || item.label
}, item );

Which means if that if the properties label and value are present in item, they will overwrite the values regardless if they are undefined or not.

This could be fixed by reversing the order and use an empty object as target:

return $.extend({}, item, {
    label: item.label || item.value,
    value: item.value || item.label
});

So if the item is:

{ 
  label: 'Hello',
  value: null
}

it will be normalized correctly to:

{ 
  label: 'Hello',
  value: 'Hello'
}

[tj.vantoll]

Hi johan-ludvigsson-stratsys,

Thanks for taking the time to contribute to jQuery UI.

Could you give an example showing this behavior in action? I'm confused how users of the widget would run into this. You can use this test case as a starting point: ​http://jsfiddle.net/tj_vantoll/hmarM/.

[johan-ludvigsson-stratsys]

I modified it to give an example: ​http://jsfiddle.net/hmarM/19/

We mostly ran into this today when we were sending out JSON-objects to populate the suggest list. The main difference you will see, is what happens when you search and select "Hello" compared to "Jquery". In the first case, the input is cleared, while in the second case the input value is changed to "JQuery".

[Scott González]

Why are you sending a null value?

[johan-ludvigsson-stratsys]

It is being serialized from an object on server side, where we may or may not depending on events set a specific value for an item.

[Scott González]

This wasn't the intention of the normalization, but I don't see any harm in supporting this.

[Scott González]

Autocomplete: Normalize falsy values, not just missing values

Fixes #9762

Changeset: 113e9d0c2cc3f474da719721857c074c983c7157