Program: 145075
Project: 145075
Buggy source:
public void questionAnswered(){
  ChatterboxWidget frame=activeFrame();
  if (activeQuestionIndex != this.model.getFormIndex()) {
    System.out.println("String_Node_Str");
    return;
  }
  if (activeIsInterstitial) {
    if (!FormIndex.EXPERIMENTAL_API) {
      String answer=((Selection)frame.getData().getValue()).getValue();
      if (answer.equals("String_Node_Str")) {
        controller.newRepeat(this.model.getFormIndex());
        createHeaderForElement(this.model.getFormIndex(),true);
      }
      step(controller.stepToNextEvent());
    }
 else {
      String answer=((Selection)frame.getData().getValue()).getValue();
      if (answer.startsWith("String_Node_Str")) {
        int n=Integer.parseInt(answer.substring(3));
        controller.jumpToIndex(model.getForm().descendIntoRepeat(activeQuestionIndex,n));
        removeFrame(this.activeQuestionIndex);
        this.activeQuestionIndex=this.model.getFormIndex();
        createHeaderForElement(activeQuestionIndex,false);
      }
 else       if (answer.equals("String_Node_Str")) {
        controller.jumpToIndex(model.getForm().descendIntoRepeat(activeQuestionIndex,-1));
        controller.newRepeat(this.model.getFormIndex());
        removeFrame(this.activeQuestionIndex);
        this.activeQuestionIndex=this.model.getFormIndex();
        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(model.getForm().descendIntoRepeat(activeQuestionIndex,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);
    }
 else     if (status == FormEntryController.ANSWER_CONSTRAINT_VIOLATED) {
      String msg=frame.getPrompt().getConstraintText();
      this.queueError(null,msg != null ? msg : PROMPT_DEFAULT_CONSTRAINT_VIOL);
    }
 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) {
    if (frame.getData() == null) {
      this.queueError(null,PROMPT_REQUIRED_QUESTION);
      return;
    }
    String answer=((Selection)frame.getData().getValue()).getValue();
    if (!FormIndex.EXPERIMENTAL_API) {
      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")) {
        int n=Integer.parseInt(answer.substring(3));
        controller.jumpToIndex(model.getForm().descendIntoRepeat(activeQuestionIndex,n));
        removeFrame(this.activeQuestionIndex);
        this.activeQuestionIndex=this.model.getFormIndex();
        createHeaderForElement(activeQuestionIndex,false);
      }
 else       if (answer.equals("String_Node_Str")) {
        controller.jumpToIndex(model.getForm().descendIntoRepeat(activeQuestionIndex,-1));
        controller.newRepeat(this.model.getFormIndex());
        removeFrame(this.activeQuestionIndex);
        this.activeQuestionIndex=this.model.getFormIndex();
        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(model.getForm().descendIntoRepeat(activeQuestionIndex,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);
    }
 else     if (status == FormEntryController.ANSWER_CONSTRAINT_VIOLATED) {
      String msg=frame.getPrompt().getConstraintText();
      this.queueError(null,msg != null ? msg : PROMPT_DEFAULT_CONSTRAINT_VIOL);
    }
 else {
      step(controller.stepToNextEvent());
    }
  }
}