Program: 62526
Project: 62526
Buggy source:
/** 
 * Adds a window to this workspace window. If the window already exists, it will be activated.
 * @param topComponent The window to add.
 */
public void addTopComponent(TopComponent topComponent){
  List<TabData> tabs=tabbedContainer.getModel().getTabs();
  for (  TabData tab : tabs) {
    JInternalFrame internalFrame=tabToFrameMap.get(tab);
    if (topComponent == getTopComponent(internalFrame)) {
      try {
        internalFrame.setSelected(true);
      }
 catch (      PropertyVetoException e) {
      }
      return;
    }
  }
  if (topComponent.isOpened()) {
    topComponent.close();
  }
  JInternalFrame internalFrame=new JInternalFrame(topComponent.getDisplayName(),true,true,true,true);
  Image iconImage=topComponent.getIcon();
  ImageIcon imageIcon=null;
  if (iconImage != null) {
    imageIcon=new ImageIcon(iconImage);
    internalFrame.setFrameIcon(imageIcon);
  }
  JComponent dummyComponent=new JPanel();
  dummyComponent.setPreferredSize(new Dimension(-1,4));
  TabData tabData=new TabData(dummyComponent,imageIcon,topComponent.getDisplayName(),null);
  frameToTabMap.put(internalFrame,tabData);
  tabToFrameMap.put(tabData,internalFrame);
  internalFrame.setContentPane(topComponent);
  Object internalFrameID=getInternalFrameID(topComponent);
  Rectangle bounds=idToBoundsMap.get(internalFrameID);
  if (bounds == null) {
    int count=frameToTabMap.size() % 5;
    bounds=new Rectangle(count * 24,count * 24,400,400);
  }
  internalFrame.setBounds(bounds);
  tabbedContainer.getModel().addTab(tabbedContainer.getModel().size(),tabData);
  tabbedContainer.setVisible(true);
  desktopPane.add(internalFrame);
  internalFrame.addInternalFrameListener(internalFrameListener);
  internalFrame.setVisible(true);
  try {
    internalFrame.setSelected(true);
  }
 catch (  PropertyVetoException e) {
  }
  topComponent.addPropertyChangeListener(propertyChangeListener);
}

Fixed version (ground truth):
/** 
 * Adds a window to this workspace window. If the window already exists, it will be activated.
 * @param topComponent The window to add.
 */
@Messages("String_Node_Str") public void addTopComponent(TopComponent topComponent){
  List<TabData> tabs=tabbedContainer.getModel().getTabs();
  for (  TabData tab : tabs) {
    JInternalFrame internalFrame=tabToFrameMap.get(tab);
    if (topComponent == getTopComponent(internalFrame)) {
      try {
        internalFrame.setSelected(true);
      }
 catch (      PropertyVetoException e) {
      }
      return;
    }
  }
  if (topComponent.isOpened()) {
    topComponent.close();
  }
  String displayName=topComponent.getDisplayName();
  if (displayName == null) {
    displayName=Bundle.CTL_WorkspaceTopComponentFrameUnnamed();
  }
  JInternalFrame internalFrame=new JInternalFrame(displayName,true,true,true,true);
  Image iconImage=topComponent.getIcon();
  ImageIcon imageIcon=null;
  if (iconImage != null) {
    imageIcon=new ImageIcon(iconImage);
    internalFrame.setFrameIcon(imageIcon);
  }
  JComponent dummyComponent=new JPanel();
  dummyComponent.setPreferredSize(new Dimension(-1,4));
  TabData tabData=new TabData(dummyComponent,imageIcon,displayName,null);
  frameToTabMap.put(internalFrame,tabData);
  tabToFrameMap.put(tabData,internalFrame);
  internalFrame.setContentPane(topComponent);
  Object internalFrameID=getInternalFrameID(topComponent);
  Rectangle bounds=idToBoundsMap.get(internalFrameID);
  if (bounds == null) {
    int count=frameToTabMap.size() % 5;
    bounds=new Rectangle(count * 24,count * 24,400,400);
  }
  internalFrame.setBounds(bounds);
  tabbedContainer.getModel().addTab(tabbedContainer.getModel().size(),tabData);
  tabbedContainer.setVisible(true);
  desktopPane.add(internalFrame);
  internalFrame.addInternalFrameListener(internalFrameListener);
  internalFrame.setVisible(true);
  try {
    internalFrame.setSelected(true);
  }
 catch (  PropertyVetoException e) {
  }
  topComponent.addPropertyChangeListener(propertyChangeListener);
}