rem: client.prefBranch.setBoolPref (prefName, client.munger.entries[ary[1]].enabled); 
add: entry = client.munger.entries[ary[1]]; if (entry.enabled != entry.enabledDefault) client.prefBranch.setBoolPref(prefName, entry.enabled); else clearPref (prefName); 
context: function writePref(prefName){    //if (prefName.indexOf("extensions.irc." == 0))    //    prefName = prefName.substr(15);    var ary;    if (prefName in client.prefSpecs)    {        var varName = client.prefSpecs[prefName][0];        var defaultValue = client.prefSpecs[prefName][1];        var prefValue = eval(varName);                if (typeof defaultValue == "boolean")            client.prefBranch.setBoolPref(prefName, prefValue);        else if (typeof defaultValue == "number")            client.prefBranch.setIntPref(prefName, prefValue);        else if (defaultValue instanceof Array)            client.prefBranch.setCharPref(prefName, prefValue.join("; "));        else            client.prefBranch.setCharPref(prefName, prefValue);    }    else if ((ary = prefName.match(/munger\.(.*)/)) &&              ary[1] in client.munger.entries)    {        client.prefBranch.setBoolPref (prefName,                                       client.munger.entries[ary[1]].enabled);    }    else    {        dd ("writePref: UNKNOWN PREF ``" + prefName + "''");    }    if (!("prefLock" in client))        client.prefService.savePrefFile(null);}
meta: 1567	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/1567/5effcc381bf78f4b464c1592cdaa2534669a9035/readprefs.js/buggy/xul/content/readprefs.js