rem: if (!engines || engines.length == 0) { if (searchButton.hasAttribute("addengines")) searchButton.removeAttribute("addengines"); } else { searchButton.setAttribute("addengines", "true"); } 
add: if (engines && engines.length > 0) searchBar.searchButton.setAttribute("addengines", "true"); else searchBar.searchButton.removeAttribute("addengines"); 
context:   updateSearchButton: function() {    var searchButton = document.getAnonymousElementByAttribute(this.getSearchBar(),                                "anonid", "searchbar-engine-button");    if (!searchButton)      return;    var engines = gBrowser.mCurrentBrowser.engines;    if (!engines || engines.length == 0) {      if (searchButton.hasAttribute("addengines"))        searchButton.removeAttribute("addengines");    }    else {      searchButton.setAttribute("addengines", "true");    }  },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/10234/bd2b254d12ebf93d37bbbce6eba176b7bad15131/browser.js/buggy/browser/base/content/browser.js