Program: 61479
Project: 61479
Buggy source:
/** 
 * Returns randomly an ingredient
 * @param modificationPoint
 * @param operator
 * @param baseIngredient
 * @return
 */
public Ingredient getNotUsedTransformedElement(ModificationPoint modificationPoint,AstorOperator operator,Ingredient baseIngredient){
  log.debug("String_Node_Str" + baseIngredient + "String_Node_Str"+ ((CtType)baseIngredient.getCode().getParent(CtType.class)).getQualifiedName());
  List<Ingredient> ingredientsAfterTransformation=null;
  if (ingredientTransformationStrategy != null) {
    String key=getKey(modificationPoint,operator) + baseIngredient.toString();
    if (appliedIngredientsCache.containsKey(key)) {
      log.debug("String_Node_Str");
      ingredientsAfterTransformation=appliedIngredientsCache.get(key);
    }
 else {
      log.debug("String_Node_Str");
      ingredientsAfterTransformation=ingredientTransformationStrategy.transform(modificationPoint,baseIngredient);
      appliedIngredientsCache.put(key,ingredientsAfterTransformation);
    }
    if (ingredientsAfterTransformation == null || ingredientsAfterTransformation.isEmpty()) {
      log.debug("String_Node_Str" + baseIngredient);
      Stats.currentStat.addSize(Stats.currentStat.combinationByIngredientSize,0);
      return null;
    }
    log.debug(String.format("String_Node_Str",ingredientsAfterTransformation.size()));
    Stats.currentStat.addSize(Stats.currentStat.combinationByIngredientSize,ingredientsAfterTransformation.size());
    Ingredient transformedIngredient=null;
    int attempts=0;
    while (attempts <= ingredientsAfterTransformation.size()) {
      transformedIngredient=getOneIngredientFromList(ingredientsAfterTransformation);
      if (transformedIngredient == null) {
        log.debug("String_Node_Str");
        continue;
      }
      boolean removed=ingredientsAfterTransformation.remove(transformedIngredient);
      if (!removed) {
        log.debug("String_Node_Str");
      }
      attempts++;
      log.debug(String.format("String_Node_Str",attempts,ingredientsAfterTransformation.size()));
      if (transformedIngredient.getCode().toString().equals(modificationPoint.getCodeElement().toString())) {
        log.debug("String_Node_Str");
        continue;
      }
      boolean alreadyApplied=alreadySelected(modificationPoint,transformedIngredient.getCode(),operator);
      if (!alreadyApplied) {
        return transformedIngredient;
      }
    }
    log.debug(String.format("String_Node_Str",attempts,ingredientsAfterTransformation.size()));
  }
  return null;
}

Fixed version (ground truth):
/** 
 * Returns randomly an ingredient
 * @param modificationPoint
 * @param operator
 * @param baseIngredient
 * @return
 */
public Ingredient getNotUsedTransformedElement(ModificationPoint modificationPoint,AstorOperator operator,Ingredient baseIngredient){
  log.debug("String_Node_Str" + baseIngredient + "String_Node_Str"+ ((CtType)baseIngredient.getCode().getParent(CtType.class)).getQualifiedName());
  List<Ingredient> ingredientsAfterTransformation=null;
  if (ingredientTransformationStrategy != null) {
    String key=getKey(modificationPoint,operator) + baseIngredient.toString();
    if (appliedIngredientsCache.containsKey(key)) {
      log.debug("String_Node_Str");
      ingredientsAfterTransformation=appliedIngredientsCache.get(key);
    }
 else {
      log.debug("String_Node_Str");
      ingredientsAfterTransformation=ingredientTransformationStrategy.transform(modificationPoint,baseIngredient);
      appliedIngredientsCache.put(key,ingredientsAfterTransformation);
    }
    if (ingredientsAfterTransformation == null || ingredientsAfterTransformation.isEmpty()) {
      log.debug("String_Node_Str" + baseIngredient);
      Stats.currentStat.addSize(Stats.currentStat.combinationByIngredientSize,0);
      return null;
    }
    log.debug(String.format("String_Node_Str",modificationPoint.getCodeElement(),baseIngredient,ingredientsAfterTransformation.size()));
    Stats.currentStat.addSize(Stats.currentStat.combinationByIngredientSize,ingredientsAfterTransformation.size());
    Ingredient transformedIngredient=null;
    int attempts=0;
    while (attempts <= ingredientsAfterTransformation.size()) {
      transformedIngredient=getOneIngredientFromList(ingredientsAfterTransformation);
      if (transformedIngredient == null) {
        log.debug("String_Node_Str");
        continue;
      }
      boolean removed=ingredientsAfterTransformation.remove(transformedIngredient);
      if (!removed) {
        log.debug("String_Node_Str");
      }
      attempts++;
      log.debug(String.format("String_Node_Str",attempts,ingredientsAfterTransformation.size()));
      if (transformedIngredient.getCode().toString().equals(modificationPoint.getCodeElement().toString())) {
        log.debug("String_Node_Str");
        continue;
      }
      boolean alreadyApplied=alreadySelected(modificationPoint,transformedIngredient.getCode(),operator);
      if (!alreadyApplied) {
        return transformedIngredient;
      }
    }
    log.debug(String.format("String_Node_Str",attempts,ingredientsAfterTransformation.size()));
  }
  return null;
}