Support repeatedly selecting suggestions in FF and IE

[torsjonas]

It appears that selecting a suggestion only works as expected in Chrome. After the first time in FF and IE, when selecting a second suggestion the index of the selected suggestion is not correct/undefined and the inputValue is set to undefined.

This can be repeated on the demo page of paper-typeahead-input:
http://cheonhyangzhang.github.io/paper-typeahead-input/components/paper-typeahead-input/

On the demo page for entering US states, in FF or IE

1. Select Oregon. Oregon is set as the inputValue.
2. Select Washington. undefined is set as the inputValue.

I have managed to avoid this problem in IE and FF with the following code in the _select function:

// These two lines only work in Chrome (and only the first time in IE and FF)
// index = Number(suggestionsMenu.indexOf(selectedItem));
// this.inputValue = this._suggestions[index];

// The following lines work in Chrome, FF and IE
index = this._suggestions.indexOf(e.model.item);
this.inputValue = this._suggestions[index];

[cheonhyangzhang]

I have tested with FF, the bug is able to be repeated.
I will try your solution to avoid the problem.

[cheonhyangzhang]

Similar bug is found for FireFox, #8

[torsjonas]

There is also a similar bug when using arrow key down to move the focused suggestion. Key down to select index 0 of suggestions does not work.

[cheonhyangzhang]

Yes. It seems in Firefox, after first selection, any further suggestions list has wrong index.
Say in the second time, suggestion list of [A, B, C], index for each element is 3, 4, 5 instead of 0, 1, 2.
So that down key stops working because we are trying to select 0 but there is no element with index 0, and selection failed because when you select, the index is 3 and there is not array[3], so it turns to be undefined to the input value.

This is the reason behind the scene. Caused by confusing index in Firefox.

Haven't found an element solution so far.