Issue URL: http://www.netbeans.org/issues/show_bug.cgi?id=81805

Steps to reproduce:
1) Start NB IDE
2) Invoke File | Open Project
3) Select empty folder
4) Double click the button 'Open Project Folder'

Following exception is thrown:
java.lang.IndexOutOfBoundsException: Invalid index
at javax.swing.DefaultRowSorter.convertRowIndexToModel(DefaultRowSorter.java:497)
at sun.swing.FilePane$SortableListModel.getElementAt(FilePane.java:525)
at javax.swing.JList.getSelectedValues(JList.java:2234)
at sun.swing.FilePane.setFileSelected(FilePane.java:1327)
at sun.swing.FilePane.doSelectedFilesChanged(FilePane.java:1430)
at sun.swing.FilePane.propertyChange(FilePane.java:1485)
... (full stack trace is attached)