Program: 144910
Project: 144910
Buggy source:
public void questionAnswered(){
  ChatterboxWidget frame=activeFrame();
  if (activeQuestionIndex != this.model.getFormIndex()) {
    System.out.println("String_Node_Str");
    return;
  }
  if (activeIsInterstitial) {
    if (frame.getData() == null) {
      this.queueError(null,PROMPT_REQUIRED_QUESTION,null,null);
      return;
    }
    String answer=((Selection)frame.getData().getValue()).getValue();
    if (FormEntryModel.REPEAT_STRUCTURE_NON_LINEAR != model.getRepeatStructure()) {
      if (answer.equals("String_Node_Str")) {
        controller.newRepeat(this.model.getFormIndex());
        createHeaderForElement(this.model.getFormIndex(),true);
      }
      step(controller.stepToNextEvent());
    }
 else {
      if (answer.startsWith("String_Node_Str")) {
        removeFrame(this.activeQuestionIndex);
        int n=Integer.parseInt(answer.substring(3));
        this.activeQuestionIndex=controller.descendIntoRepeat(n);
        createHeaderForElement(activeQuestionIndex,false);
      }
 else       if (answer.equals("String_Node_Str")) {
        removeFrame(this.activeQuestionIndex);
        uncommittedRepeats.addElement(this.activeQuestionIndex);
        this.activeQuestionIndex=controller.descendIntoNewRepeat();
        createHeaderForElement(activeQuestionIndex,false);
      }
 else       if (answer.equals("String_Node_Str")) {
        deleteInterstitial=true;
        jumpToQuestion(this.activeQuestionIndex);
        return;
      }
 else       if (answer.startsWith("String_Node_Str")) {
        int n=Integer.parseInt(answer.substring(3));
        controller.deleteRepeat(n);
        deleteInterstitial=false;
        jumpToQuestion(this.activeQuestionIndex);
        return;
      }
 else       if (answer.equals("String_Node_Str")) {
      }
      step(controller.stepToNextEvent());
    }
  }
 else {
    int status=controller.answerQuestion(this.model.getFormIndex(),frame.getData());
    if (status == FormEntryController.ANSWER_REQUIRED_BUT_EMPTY) {
      this.queueError(null,PROMPT_REQUIRED_QUESTION,null,null);
    }
 else     if (status == FormEntryController.ANSWER_CONSTRAINT_VIOLATED) {
      String msg=frame.getPrompt().getConstraintText(frame.getData());
      String image=frame.getPrompt().getConstraintText(FormEntryCaption.TEXT_FORM_IMAGE,frame.getData());
      String audio=frame.getPrompt().getConstraintText(FormEntryCaption.TEXT_FORM_AUDIO,frame.getData());
      this.queueError(null,msg != null ? msg : PROMPT_DEFAULT_CONSTRAINT_VIOL,image,audio);
    }
 else {
      step(controller.stepToNextEvent());
    }
  }
}

Fixed version (ground truth):
public void questionAnswered(){
  ChatterboxWidget frame=activeFrame();
  if (activeQuestionIndex != this.model.getFormIndex()) {
    System.out.println("String_Node_Str");
    return;
  }
  if (activeIsInterstitial) {
    IAnswerData frameData;
    try {
      frameData=frame.getData();
    }
 catch (    InvalidDataException e) {
      throw new IllegalArgumentException("String_Node_Str" + e.getMessage());
    }
    if (frameData == null) {
      this.queueError(null,PROMPT_REQUIRED_QUESTION,null,null);
      return;
    }
    String answer=((Selection)frameData.getValue()).getValue();
    if (FormEntryModel.REPEAT_STRUCTURE_NON_LINEAR != model.getRepeatStructure()) {
      if (answer.equals("String_Node_Str")) {
        controller.newRepeat(this.model.getFormIndex());
        createHeaderForElement(this.model.getFormIndex(),true);
      }
      step(controller.stepToNextEvent());
    }
 else {
      if (answer.startsWith("String_Node_Str")) {
        removeFrame(this.activeQuestionIndex);
        int n=Integer.parseInt(answer.substring(3));
        this.activeQuestionIndex=controller.descendIntoRepeat(n);
        createHeaderForElement(activeQuestionIndex,false);
      }
 else       if (answer.equals("String_Node_Str")) {
        removeFrame(this.activeQuestionIndex);
        uncommittedRepeats.addElement(this.activeQuestionIndex);
        this.activeQuestionIndex=controller.descendIntoNewRepeat();
        createHeaderForElement(activeQuestionIndex,false);
      }
 else       if (answer.equals("String_Node_Str")) {
        deleteInterstitial=true;
        jumpToQuestion(this.activeQuestionIndex);
        return;
      }
 else       if (answer.startsWith("String_Node_Str")) {
        int n=Integer.parseInt(answer.substring(3));
        controller.deleteRepeat(n);
        deleteInterstitial=false;
        jumpToQuestion(this.activeQuestionIndex);
        return;
      }
 else       if (answer.equals("String_Node_Str")) {
      }
      step(controller.stepToNextEvent());
    }
  }
 else {
    IAnswerData data;
    try {
      data=frame.getData();
    }
 catch (    InvalidDataException e) {
      IAnswerData uncast=e.getUncastStandin();
      String msg=frame.getPrompt().getConstraintText(uncast);
      if (msg == null) {
        this.queueError(null,e.getMessage(),null,null);
        return;
      }
 else {
        String image=frame.getPrompt().getConstraintText(FormEntryCaption.TEXT_FORM_IMAGE,uncast);
        String audio=frame.getPrompt().getConstraintText(FormEntryCaption.TEXT_FORM_AUDIO,uncast);
        this.queueError(null,msg,image,audio);
        return;
      }
    }
    int status=controller.answerQuestion(this.model.getFormIndex(),data);
    if (status == FormEntryController.ANSWER_REQUIRED_BUT_EMPTY) {
      this.queueError(null,PROMPT_REQUIRED_QUESTION,null,null);
    }
 else     if (status == FormEntryController.ANSWER_CONSTRAINT_VIOLATED) {
      String msg=frame.getPrompt().getConstraintText(data);
      String image=frame.getPrompt().getConstraintText(FormEntryCaption.TEXT_FORM_IMAGE,data);
      String audio=frame.getPrompt().getConstraintText(FormEntryCaption.TEXT_FORM_AUDIO,data);
      this.queueError(null,msg != null ? msg : PROMPT_DEFAULT_CONSTRAINT_VIOL,image,audio);
    }
 else {
      step(controller.stepToNextEvent());
    }
  }
}