searchbar-panel-one-offs-height.uc.js

// ==UserScript==
// @name           searchbar-panel-one-offs height
// @description    49px固定だと高さズレるんだよ！
// @version        1.0
// @author         oflow
// @compatibility  Firefox 38
// ==/UserScript==


(function() {
    var popup     = document.getElementById('PopupSearchAutoComplete'),
        searchbar = document.getElementById('searchbar');

    popup.addEventListener('popupshowing', function() {
        let list   = document.getAnonymousElementByAttribute(popup, 'anonid', 'search-panel-one-offs'),
            len    = searchbar.engines.length,
            width  = parseInt(popup.clientWidth),
            row    = Math.floor(width / 27);
            height = Math.ceil(len / row) * 25 + 10;

        list.setAttribute('height', height + 'px');
    }, false);
})();