Program: 32600
Project: 32600
Buggy source:
/** 
 * Decorate all necessary areas of the current UI to install autocompletion support. This method is called in the constructor and when the comboBox's UI delegate is changed.
 */
private void decorateCurrentUI(){
  this.originalRenderer=comboBox.getRenderer();
  this.popupMenu=(JPopupMenu)comboBox.getUI().getAccessibleChild(comboBox,0);
  this.popup=(ComboPopup)popupMenu;
  this.arrowButton=findArrowButton(comboBox);
  if (this.arrowButton != null) {
    this.arrowButton.removeMouseListener(popup.getMouseListener());
    this.arrowButtonMouseListener=new ArrowButtonMouseListener(popup.getMouseListener());
    this.arrowButton.addMouseListener(arrowButtonMouseListener);
  }
  this.comboBox.getModel().addListDataListener(listDataHandler);
  this.popupMenu.addPopupMenuListener(popupSizerHandler);
  this.popup.getList().addMouseListener(popupMouseHandler);
  final ActionMap actionMap=comboBox.getActionMap();
  this.originalSelectNextAction=actionMap.get("String_Node_Str");
  this.originalSelectPreviousAction=actionMap.get("String_Node_Str");
  this.originalSelectNext2Action=actionMap.get("String_Node_Str");
  this.originalSelectPrevious2Action=actionMap.get("String_Node_Str");
  this.originalAquaSelectNextAction=actionMap.get("String_Node_Str");
  this.originalAquaSelectPreviousAction=actionMap.get("String_Node_Str");
  final Action upAction=new MoveAction(-1);
  final Action downAction=new MoveAction(1);
  actionMap.put("String_Node_Str",upAction);
  actionMap.put("String_Node_Str",downAction);
  actionMap.put("String_Node_Str",upAction);
  actionMap.put("String_Node_Str",downAction);
  actionMap.put("String_Node_Str",upAction);
  actionMap.put("String_Node_Str",downAction);
  this.comboBoxEditor=new FormatComboBoxEditor(comboBox.getEditor());
  this.comboBox.setEditor(comboBoxEditor);
  this.comboBoxEditorComponent=(JTextField)comboBox.getEditor().getEditorComponent();
  this.document=(AbstractDocument)comboBoxEditorComponent.getDocument();
  this.document.setDocumentFilter(documentFilter);
  if (this.renderer != null)   comboBox.setRenderer(renderer);
  this.comboBoxEditorComponent.addKeyListener(strictModeBackspaceHandler);
  this.comboBoxEditorComponent.addFocusListener(selectTextOnFocusGainHandler);
}

Fixed version (ground truth):
/** 
 * Decorate all necessary areas of the current UI to install autocompletion support. This method is called in the constructor and when the comboBox's UI delegate is changed.
 */
private void decorateCurrentUI(){
  this.originalRenderer=comboBox.getRenderer();
  this.popupMenu=(JPopupMenu)comboBox.getUI().getAccessibleChild(comboBox,0);
  this.popup=(ComboPopup)popupMenu;
  this.arrowButton=findArrowButton(comboBox);
  if (this.arrowButton != null) {
    this.arrowButton.removeMouseListener(popup.getMouseListener());
    this.arrowButtonMouseListener=new ArrowButtonMouseListener(popup.getMouseListener());
    this.arrowButton.addMouseListener(arrowButtonMouseListener);
  }
  this.comboBox.getModel().addListDataListener(listDataHandler);
  this.popupMenu.addPopupMenuListener(popupSizerHandler);
  this.popupLocationFix=ComboBoxPopupLocationFix.install(this.comboBox);
  this.popup.getList().addMouseListener(popupMouseHandler);
  final ActionMap actionMap=comboBox.getActionMap();
  this.originalSelectNextAction=actionMap.get("String_Node_Str");
  this.originalSelectPreviousAction=actionMap.get("String_Node_Str");
  this.originalSelectNext2Action=actionMap.get("String_Node_Str");
  this.originalSelectPrevious2Action=actionMap.get("String_Node_Str");
  this.originalAquaSelectNextAction=actionMap.get("String_Node_Str");
  this.originalAquaSelectPreviousAction=actionMap.get("String_Node_Str");
  final Action upAction=new MoveAction(-1);
  final Action downAction=new MoveAction(1);
  actionMap.put("String_Node_Str",upAction);
  actionMap.put("String_Node_Str",downAction);
  actionMap.put("String_Node_Str",upAction);
  actionMap.put("String_Node_Str",downAction);
  actionMap.put("String_Node_Str",upAction);
  actionMap.put("String_Node_Str",downAction);
  this.comboBoxEditor=new FormatComboBoxEditor(comboBox.getEditor());
  this.comboBox.setEditor(comboBoxEditor);
  this.comboBoxEditorComponent=(JTextField)comboBox.getEditor().getEditorComponent();
  this.document=(AbstractDocument)comboBoxEditorComponent.getDocument();
  this.document.setDocumentFilter(documentFilter);
  if (this.renderer != null)   comboBox.setRenderer(renderer);
  this.comboBoxEditorComponent.addKeyListener(strictModeBackspaceHandler);
  this.comboBoxEditorComponent.addFocusListener(selectTextOnFocusGainHandler);
}