rem: var tocDSArray = gTocDSList.split(/\s+/); 
add: var tocDSArray = gTocDSList.split(/\s+/) .filter(function(x) { return x != "rdf:null"; }); 
context: function getLink(ID) {    if (!ID)      return null;    var tocDS = document.getElementById("help-toc-panel").database;    if (!tocDS)      return null;    // URIs include both the ID part and the base file name,    // so we need to check for a matching ID in each datasource    var tocDSArray = gTocDSList.split(/\s+/);    for (var i = 0; i < tocDSArray.length; i++) {      var resource = RDF.GetResource(tocDSArray[i] + "#" + ID);      var link = tocDS.GetTarget(resource, NC_LINK, true);      if (!link)  // no such rdf:ID found        continue;      return link.QueryInterface(Components.interfaces.nsIRDFLiteral).Value;    }    return null;}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/a94d29f92e98f10b909eb2f5b86a209eeb001e2b/help.js/clean/toolkit/components/help/content/help.js