Autocomplete: Errors on empty responses

PROBLEM:

When the source is a service and it returns an empty response body, a javascript error occurs. Some service languages, such as .net, will return an empty body when the request is terminated mid stream, such as pressing enter in the text box too fast before the suggestions are displayed.

CAUSE:

The response handler does not check to see if the content parameter is null before attempting to check its length.

WORKAROUND:

override the response handler in the following manner to mitigate the issue:

$.ui.autocomplete.prototype._response = function( content ) {
	if ( content && content.length ) {
		content = this._normalize( content );
		this._suggest( content );
		this._trigger( "open" );
	} else {
		this.close();
	}
	this.element.removeClass( "ui-autocomplete-loading" );
};