rem: if (toDoItem.start && oeICalDateTime_isSet(toDoItem.start)) 
add: if (toDoItem.start && toDoItem.start.isSet) 
context: function getPreviewForTask( toDoItem ){  if( toDoItem )  {    gShowTooltip = true; //needed to show the tooltip.    const vbox = document.createElement( "vbox" );    boxInitializeHeaderGrid(vbox);    var hasHeader = false;             if (toDoItem.title)    {      boxAppendLabeledText(vbox, "tooltipTitle", toDoItem.title);      hasHeader = true;    }    if (toDoItem.location)    {      boxAppendLabeledText(vbox, "tooltipLocation", toDoItem.location);      hasHeader = true;    }       if (toDoItem.start && oeICalDateTime_isSet(toDoItem.start))    {      var startDate = new Date( toDoItem.start.getTime() );      boxAppendLabeledDateTime(vbox, "tooltipStart", startDate, toDoItem.allDay);      hasHeader = true;    }       if (toDoItem.due && oeICalDateTime_isSet(toDoItem.due))    {      var dueDate = new Date( toDoItem.due.getTime() );      boxAppendLabeledDateTime(vbox, "tooltipDue", dueDate, toDoItem.allDay);      hasHeader = true;    }       if (toDoItem.priority && toDoItem.priority != 0)    {      boxAppendLabeledText(vbox, "tooltipPriority", String(toDoItem.priority));      hasHeader = true;    }    if (toDoItem.status && toDoItem.status != toDoItem.ICAL_STATUS_NONE)    {      var status = getToDoStatusString(toDoItem);      boxAppendLabeledText(vbox, "tooltipStatus", status);      hasHeader = true;    }    if (toDoItem.percent && toDoItem.percent != 0)    {      boxAppendLabeledText(vbox, "tooltipPercent", String(toDoItem.percent)+"%");      hasHeader = true;    }    if (toDoItem.completed && oeICalDateTime_isSet(toDoItem.completed))    {      var completedDate = new Date( toDoItem.completed.getTime() );      boxAppendLabeledDateTime(vbox, "tooltipCompleted", completedDate, toDoItem.allDay);      hasHeader = true;    }    if (toDoItem.description)    {      // display up to 4 description lines like body of message below headers      if (hasHeader)        boxAppendText(vbox, "");       boxAppendLines(vbox, toDoItem.description, 4);    }          return ( vbox );  }   else  {    gShowTooltip = false; //Don't show the tooltip    return null;  }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/9be3f570ca2e9ff93e5387d5d434c50917674cf9/mouseoverPreviews.js/buggy/calendar/resources/content/mouseoverPreviews.js