output: #fixed code
                                  public SlocCount countStats(String contents, String languageName) {
          if (contents == null || contents.isEmpty()) {
              return new SlocCount();
          }
  
          FileClassifierResult fileClassifierResult = this.database.get(languageName);
  
          State currentState = State.S_BLANK;
  
          int endPoint = contents.length() - 1;
          String endString = null;
          ArrayList<String> endComments = new ArrayList<>();
          int linesCount = 0;
          int blankCount = 0;
          int codeCount = 0;
          int commentCount = 0;
          int complexity = 0;
  
          for (int index=0; index < contents.length(); index++) {
  
              if (!isWhitespace(contents.charAt(index))) {
                  switch (currentState) {
                      case S_CODE:
                          if (fileClassifierResult.nestedmultiline || endComments.size() == 0) {
                              endString = this.checkForMatchMultiOpen(contents.charAt(index), index, endPoint, fileClassifierResult.multi_line, contents);
                              if (endString != null) {
                                  endComments.add(endString);
                                  currentState = State.S_MULTICOMMENT_CODE;
                                  break;
                              }
                          }
  
                          if (this.checkForMatch(contents.charAt(index), index, endPoint, fileClassifierResult.line_comment, contents)) {
                              currentState = State.S_COMMENT_CODE;
                              break;
                          }
  
                          endString = this.checkForMatchMultiOpen(contents.charAt(index), index, endPoint, fileClassifierResult.quotes, contents);
                          if (endString != null) {
                              currentState = State.S_STRING;
                              break;
                          } else if (this.checkForMatch(contents.charAt(index), index, endPoint, fileClassifierResult.complexitychecks, contents)) {
                              complexity++;
                          }
                          break;
                      case S_MULTICOMMENT_BLANK:
                          if (this.checkForMatch(contents.charAt(index), index, endPoint, fileClassifierResult.line_comment, contents)) {
                              currentState = State.S_COMMENT;
                              break;
                          }
  
                          endString = this.checkForMatchMultiOpen(contents.charAt(index), index, endPoint, fileClassifierResult.multi_line, contents);
                          if (endString != null) {
                              currentState = State.S_MULTICOMMENT;
                              break;
                          }
  
                          endString = this.checkForMatchMultiOpen(contents.charAt(index), index, endPoint, fileClassifierResult.quotes, contents);
                          if (endString != null) {
                              currentState = State.S_STRING;
                              break;
                          }
  
                          if (!this.isWhitespace(contents.charAt(index))) {
                              currentState = State.S_CODE;
  
                              if (this.checkForMatch(contents.charAt(index), index, endPoint, fileClassifierResult.complexitychecks, contents)) {
                                  complexity++;
                              }
                          }
                          break;
                      case S_STRING:
                          if (contents.charAt(index - 1) != '\\' && this.checkForMatchSingle(contents.charAt(index), index, endPoint, endString, contents)) {
                              currentState = State.S_CODE;
                          }
                          break;
                      case S_MULTICOMMENT:
                      case S_MULTICOMMENT_CODE:
                          if (this.checkForMatchMultiClose(contents.charAt(index), index, endPoint, fileClassifierResult.multi_line, contents)) {
                              if (currentState == State.S_MULTICOMMENT_CODE) {
                                  currentState = State.S_CODE;
                              } else {
                                  // TODO check if out of bounds
                                  if (index + 1 <= endPoint && this.isWhitespace(contents.charAt(index + 1))) {
                                      currentState = State.S_MULTICOMMENT_BLANK;
                                  } else {
                                      currentState = State.S_MULTICOMMENT_CODE;
                                  }
                              }
                          }
                          break;
                  }
              }
  
              // This means the end of processing the line so calculate the stats according to what state
              // we are currently in
              if (contents.charAt(index) == '\n' || index == endPoint) {
                  linesCount++;
  
                  switch (currentState) {
                      case S_BLANK:
                          blankCount++;
                          break;
                      case S_COMMENT:
                      case S_MULTICOMMENT:
                      case S_MULTICOMMENT_BLANK:
                          commentCount++;
                          break;
                      case S_CODE:
                      case S_STRING:
                      case S_COMMENT_CODE:
                      case S_MULTICOMMENT_CODE:
                          codeCount++;
                          break;
                  }
  
                  // If we are in a multiline comment that started after some code then we need
                  // to move to a multiline comment if a multiline comment then stay there
                  // otherwise we reset back into a blank state
                  if (currentState != State.S_MULTICOMMENT && currentState != State.S_MULTICOMMENT_CODE) {
                      currentState = State.S_BLANK;
                  } else {
                      currentState = State.S_MULTICOMMENT;
                  }
              }
          }
  
          return new SlocCount(linesCount, blankCount, codeCount, commentCount, complexity);
      }
input: #vulnerable code 
                                  public SlocCount countStats(String contents, String languageName) {
          if (contents == null || contents.isEmpty()) {
              return new SlocCount();
          }
  
          FileClassifierResult fileClassifierResult = this.database.get(languageName);
  
          State currentState = State.S_BLANK;
  
          int endPoint = contents.length() - 1;
          String endString = null;
          int linesCount = 0;
          int blankCount = 0;
          int codeCount = 0;
          int commentCount = 0;
          int complexity = 0;
  
          for (int index=0; index < contents.length(); index++) {
              switch (currentState) {
                  case S_BLANK:
                  case S_MULTICOMMENT_BLANK:
                      if (this.checkForMatch(contents.charAt(index), index, endPoint, fileClassifierResult.line_comment, contents)) {
                          currentState = State.S_COMMENT;
                          break;
                      }
  
                      endString = this.checkForMatchMultiOpen(contents.charAt(index), index, endPoint, fileClassifierResult.multi_line, contents);
                      if (endString != null) {
                          currentState = State.S_MULTICOMMENT;
                          break;
                      }
  
                      endString = this.checkForMatchMultiOpen(contents.charAt(index), index, endPoint, fileClassifierResult.quotes, contents);
                      if (endString != null) {
                          currentState = State.S_STRING;
                          break;
                      }
  
                      if (!this.isWhitespace(contents.charAt(index))) {
                          currentState = State.S_CODE;
  
                          if (this.checkForMatch(contents.charAt(index), index, endPoint, fileClassifierResult.complexitychecks, contents)) {
                              complexity++;
                          }
                      }
                      break;
                  case S_CODE:
                      endString = this.checkForMatchMultiOpen(contents.charAt(index), index, endPoint, fileClassifierResult.multi_line, contents);
                      if (endString != null) {
                          currentState = State.S_MULTICOMMENT_CODE;
                          break;
                      }
  
                      endString = this.checkForMatchMultiOpen(contents.charAt(index), index, endPoint, fileClassifierResult.quotes, contents);
                      if (endString != null) {
                          currentState = State.S_STRING;
                          break;
                      } else if (this.checkForMatch(contents.charAt(index), index, endPoint, fileClassifierResult.complexitychecks, contents)) {
                          complexity++;
                      }
                      break;
                  case S_STRING:
                      if (contents.charAt(index-1) != '\\' && this.checkForMatchSingle(contents.charAt(index), index, endPoint, endString, contents)) {
                          currentState = State.S_CODE;
                      }
                      break;
                  case S_MULTICOMMENT:
                  case S_MULTICOMMENT_CODE:
                      if (this.checkForMatchMultiClose(contents.charAt(index), index, endPoint, fileClassifierResult.multi_line, contents)) {
                          if (currentState == State.S_MULTICOMMENT_CODE) {
                              currentState = State.S_CODE;
                          } else {
                              // TODO check if out of bounds
                              if (index + 1 <= endPoint && this.isWhitespace(contents.charAt(index+1))) {
                                  currentState = State.S_MULTICOMMENT_BLANK;
                              } else {
                                  currentState = State.S_MULTICOMMENT_CODE;
                              }
                          }
                      }
                      break;
              }
  
              // This means the end of processing the line so calculate the stats according to what state
              // we are currently in
              if (contents.charAt(index) == '\n' || index == endPoint) {
                  linesCount++;
  
                  switch (currentState) {
                      case S_BLANK:
                          blankCount++;
                          break;
                      case S_COMMENT:
                      case S_MULTICOMMENT:
                      case S_MULTICOMMENT_BLANK:
                          commentCount++;
                          break;
                      case S_CODE:
                      case S_STRING:
                      case S_COMMENT_CODE:
                      case S_MULTICOMMENT_CODE:
                          codeCount++;
                          break;
                  }
  
                  // If we are in a multiline comment that started after some code then we need
                  // to move to a multiline comment if a multiline comment then stay there
                  // otherwise we reset back into a blank state
                  if (currentState != State.S_MULTICOMMENT && currentState != State.S_MULTICOMMENT_CODE) {
                      currentState = State.S_BLANK;
                  } else {
                      currentState = State.S_MULTICOMMENT;
                  }
              }
          }
  
          return new SlocCount(linesCount, blankCount, codeCount, commentCount, complexity);
      } 
                              #location 22 
                              #vulnerability type NULL_DEREFERENCE