rem: if (toDoItem.dueDat && toDoItem.dueDate.isValid) 
add: if (toDoItem.dueDate && toDoItem.dueDate.isValid) 
context: function getPreviewForTask( toDoItem ){  if( toDoItem )  {    const vbox = document.createElement( "vbox" );    boxInitializeHeaderGrid(vbox);    var hasHeader = false;             if (toDoItem.title)    {      boxAppendLabeledText(vbox, "tooltipTitle", toDoItem.title);      hasHeader = true;    }    var location = toDoItem.getProperty("LOCATION");    if (location)    {      boxAppendLabeledText(vbox, "tooltipLocation", location);      hasHeader = true;    }       if (toDoItem.entryDate && toDoItem.entryDate.isValid)    {      var startDate = toDoItem.entryDate.jsDate;      boxAppendLabeledDateTime(vbox, "tooltipStart", startDate, false);      hasHeader = true;    }       if (toDoItem.dueDat && toDoItem.dueDate.isValid)    {      var dueDate = toDoItem.dueDate.jsDate;      boxAppendLabeledDateTime(vbox, "tooltipDue", dueDate, false);      hasHeader = true;    }       if (toDoItem.priority && toDoItem.priority != 0)    {      boxAppendLabeledText(vbox, "tooltipPriority", String(toDoItem.priority));      hasHeader = true;    }    if (toDoItem.status && toDoItem.status != "NONE")    {      var status = getToDoStatusString(toDoItem);      boxAppendLabeledText(vbox, "tooltipStatus", status);      hasHeader = true;    }    if (toDoItem.percentComplete != 0 && toDoItem.percentComplete != 100)    {      boxAppendLabeledText(vbox, "tooltipPercent", String(toDoItem.percentComplete)+"%");      hasHeader = true;    } else if (toDoItem.percentComplete == 100)    {      if (toDoItem.completedDate == null) {        boxAppendLabeledText(vbox, "tooltipPercent", "100%");      } else {         var completedDate = toDoItem.completedDate.jsDate;        boxAppendLabeledDateTime(vbox, "tooltipCompleted", completedDate, false);      }       hasHeader = true;    }    var description = toDoItem.getProperty("DESCRIPTION");    if (description)    {      // display up to 4 description lines like body of message below headers      if (hasHeader)        boxAppendText(vbox, "");       boxAppendLines(vbox, description, 4);    }          return ( vbox );  }   else  {    return null;  }}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/585b873e7a9829c06264839a6d0c67deea3bd054/mouseoverPreviews.js/buggy/calendar/resources/content/mouseoverPreviews.js