Program: 61421
Project: 61421
Buggy source:
public List<OperatorInstance> createInstance(SuspiciousModificationPoint modificationPoint,AstorOperator astorOperator) throws Exception {
  List<OperatorInstance> ops=new ArrayList<>();
  List<Ingredient> ingredients=new ArrayList<>();
  if (astorOperator.needIngredient()) {
    if (astorOperator instanceof ReplaceOp) {
      String type=modificationPoint.getCodeElement().getClass().getSimpleName();
      ingredients=ingredientSpace.getIngredients(modificationPoint.getCodeElement(),type);
    }
 else {
      ingredients=ingredientSpace.getIngredients(modificationPoint.getCodeElement());
    }
    if (ingredients == null) {
      log.error("String_Node_Str" + modificationPoint + "String_Node_Str"+ astorOperator);
      return ops;
    }
    log.debug("String_Node_Str" + ingredients.size());
    for (    Ingredient ingredient : ingredients) {
      CtElement ingredientElement=ingredient.getCode();
      List<OperatorInstance> instances=astorOperator.createOperatorInstance(modificationPoint);
      List<Ingredient> ingredientsAfterTransformation=this.ingredientTransformationStrategy.transform(modificationPoint,new Ingredient(ingredientElement));
      if (instances != null && instances.size() > 0) {
        for (        Ingredient ingredientTransformed : ingredientsAfterTransformation) {
          OperatorInstance operatorInstance=createOperatorInstance(modificationPoint,astorOperator);
          operatorInstance.setModified(ingredientTransformed.getCode());
          operatorInstance.setIngredient(ingredientTransformed);
          ops.add(operatorInstance);
        }
      }
    }
  }
 else {
    OperatorInstance operatorInstance=createOperatorInstance(modificationPoint,astorOperator);
    ops.add(operatorInstance);
  }
  return ops;
}

Fixed version (ground truth):
public List<OperatorInstance> createInstance(SuspiciousModificationPoint modificationPoint,AstorOperator astorOperator) throws Exception {
  List<OperatorInstance> ops=new ArrayList<>();
  List<Ingredient> ingredients=new ArrayList<>();
  if (astorOperator.needIngredient()) {
    if (astorOperator instanceof ReplaceOp) {
      String type=modificationPoint.getCodeElement().getClass().getSimpleName();
      ingredients=ingredientSpace.getIngredients(modificationPoint.getCodeElement(),type);
    }
 else {
      ingredients=ingredientSpace.getIngredients(modificationPoint.getCodeElement());
    }
    if (ingredients == null) {
      log.error("String_Node_Str" + modificationPoint + "String_Node_Str"+ astorOperator);
      return ops;
    }
    log.debug("String_Node_Str" + ingredients.size());
    for (    Ingredient ingredient : ingredients) {
      List<OperatorInstance> instances=astorOperator.createOperatorInstance(modificationPoint);
      List<Ingredient> ingredientsAfterTransformation=this.ingredientTransformationStrategy.transform(modificationPoint,ingredient);
      if (instances != null && instances.size() > 0) {
        for (        Ingredient ingredientTransformed : ingredientsAfterTransformation) {
          OperatorInstance operatorInstance=createOperatorInstance(modificationPoint,astorOperator);
          operatorInstance.setModified(ingredientTransformed.getCode());
          operatorInstance.setIngredient(ingredientTransformed);
          ops.add(operatorInstance);
        }
      }
    }
  }
 else {
    OperatorInstance operatorInstance=createOperatorInstance(modificationPoint,astorOperator);
    ops.add(operatorInstance);
  }
  return ops;
}