add: if (!str) return; 
context: function spamfilter_macro(param) {   var str = this.preferences.getProperty("spamfilter");   var items = str.replace(/\r/g, "").split("\n");   for (var i in items) {      res.write('"');      res.write(items[i]);      res.write('"');      if (i < items.length-1)         res.write(",");   }   return;}
meta: 993	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/993/9281800c2a580d67b6277f2908677e0a61fd3dd9/macros.js/buggy/code/Site/macros.js