Program: 34400
Project: 34400
Buggy source:
public void actionPerformed(final ActionEvent evt,final JTextComponent target){
  try {
    final Rectangle carretRectangle=target.modelToView(target.getCaretPosition());
    final Font font=target.getFont();
    final Point where=new Point(carretRectangle.x,carretRectangle.y + carretRectangle.height);
    SwingUtilities.convertPointToScreen(where,target);
    final int position=target.getCaretPosition();
    final String ident=Utilities.getIdentifier(Utilities.getDocument(target),position);
    FileObject file=getFile(target.getDocument());
    if (ident == null || file == null) {
      Toolkit.getDefaultToolkit().beep();
      return;
    }
    final JavaSource js=JavaSource.forFileObject(file);
    if (js == null) {
      Toolkit.getDefaultToolkit().beep();
      return;
    }
    final AtomicBoolean cancel=new AtomicBoolean();
    final Task<CompilationController> task=new Task<CompilationController>(){
      public void run(      final CompilationController parameter) throws IOException {
        parameter.toPhase(Phase.RESOLVED);
        if (cancel.get()) {
          return;
        }
        final JavaSource javaSource=parameter.getJavaSource();
        Pair<Map<String,List<Element>>,Map<String,List<Element>>> result=new ComputeImports(parameter).computeCandidates(Collections.singleton(ident));
        final List<TypeElement> priviledged=ElementFilter.typesIn(result.a.get(ident));
        if (priviledged == null) {
          Toolkit.getDefaultToolkit().beep();
          return;
        }
        final List<TypeElement> denied=new ArrayList<TypeElement>(ElementFilter.typesIn(result.b.get(ident)));
        denied.removeAll(priviledged);
        SwingUtilities.invokeLater(new Runnable(){
          public void run(){
            ImportClassPanel panel=new ImportClassPanel(priviledged,denied,font,javaSource,position,target);
            PopupUtil.showPopup(panel,"String_Node_Str",where.x,where.y,true,carretRectangle.height);
          }
        }
);
      }
    }
;
    ProgressUtils.runOffEventDispatchThread(new Runnable(){
      public void run(){
        try {
          js.runUserActionTask(task,true);
        }
 catch (        IOException ex) {
          Exceptions.printStackTrace(ex);
        }
      }
    }
,NbBundle.getMessage(FastImportAction.class,"String_Node_Str"),cancel,false);
  }
 catch (  BadLocationException ex) {
    Exceptions.printStackTrace(ex);
  }
}

Fixed version (ground truth):
public void actionPerformed(final ActionEvent evt,final JTextComponent target){
  try {
    final Rectangle carretRectangle=target.modelToView(target.getCaretPosition());
    final Font font=target.getFont();
    final Point where=new Point(carretRectangle.x,carretRectangle.y + carretRectangle.height);
    SwingUtilities.convertPointToScreen(where,target);
    final int position=target.getCaretPosition();
    final String ident=Utilities.getIdentifier(Utilities.getDocument(target),position);
    FileObject file=getFile(target.getDocument());
    if (ident == null || file == null) {
      Toolkit.getDefaultToolkit().beep();
      return;
    }
    final JavaSource js=JavaSource.forFileObject(file);
    if (js == null) {
      Toolkit.getDefaultToolkit().beep();
      return;
    }
    final AtomicBoolean cancel=new AtomicBoolean();
    final Task<CompilationController> task=new Task<CompilationController>(){
      public void run(      final CompilationController parameter) throws IOException {
        parameter.toPhase(Phase.RESOLVED);
        if (cancel.get()) {
          return;
        }
        final JavaSource javaSource=parameter.getJavaSource();
        Pair<Map<String,List<Element>>,Map<String,List<Element>>> result=new ComputeImports(parameter).computeCandidates(Collections.singleton(ident));
        List<Element> candidates=result.a.get(ident);
        if (candidates == null) {
          Toolkit.getDefaultToolkit().beep();
          return;
        }
        final List<TypeElement> priviledged=ElementFilter.typesIn(candidates);
        if (priviledged == null) {
          Toolkit.getDefaultToolkit().beep();
          return;
        }
        final List<TypeElement> denied=new ArrayList<TypeElement>(ElementFilter.typesIn(result.b.get(ident)));
        denied.removeAll(priviledged);
        SwingUtilities.invokeLater(new Runnable(){
          public void run(){
            ImportClassPanel panel=new ImportClassPanel(priviledged,denied,font,javaSource,position,target);
            PopupUtil.showPopup(panel,"String_Node_Str",where.x,where.y,true,carretRectangle.height);
          }
        }
);
      }
    }
;
    ProgressUtils.runOffEventDispatchThread(new Runnable(){
      public void run(){
        try {
          js.runUserActionTask(task,true);
        }
 catch (        IOException ex) {
          Exceptions.printStackTrace(ex);
        }
      }
    }
,NbBundle.getMessage(FastImportAction.class,"String_Node_Str"),cancel,false);
  }
 catch (  BadLocationException ex) {
    Exceptions.printStackTrace(ex);
  }
}