rem: return Boolean(row && row.childData); 
add: return Boolean(row && "childData" in row); 
context: function tov_isctr (index){    var row = this.childData.locateChildByVisualRow (index);    /*    ASSERT(row, "bogus row");    var rv = Boolean(row && row.childData);    dd ("isContainer: row " + index + " returning " + rv);    return rv;    */    return Boolean(row && row.childData);}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/89326cbcdc6feb4eef3ffc00bb488c9640e8dd81/tree-utils.js/buggy/extensions/venkman/resources/content/tree-utils.js