rem: if (this._currentEngine.hidden) 
add: if (!this._currentEngine || this._currentEngine.hidden) 
context:   get currentEngine() {    if (this._currentEngine.hidden)      this._currentEngine = this.defaultEngine;    return this._currentEngine;  },
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/236f1dfec9fdeb19ab7a5859519ea2c360ccd65a/nsSearchService.js/clean/browser/components/search/nsSearchService.js