Scoped search autocomplete submits blank string
When searching an invalid field "foo = bar" in a search box, scoped search provides the first autocomplete as a blank string. If the user hits Enter, a blank string is submitted and not the query in the search box.
To reproduce; Navigate to the search box, type "foo = bar" (without quotes) and hit enter. In the params passed to the server you will see a blank string as the search query.
If you click the search button, then "foo = bar" is submitted in the params.
Expected results: Enter submits the query in the box if there is no autocomplete results.