Adding element at end of a linked list, in function the pointer value not getting assigned? (using code::blocks)

I have been trying to implement function to add element at the end of an linked list but it is not working.

I tried to debug code in code::blocks and found that "h->next = newNode;" is not assigning the value.

#include <iostream>

using namespace std;

class Node {
  public:
    int data;
  Node * next;
};

void pushend(Node * h, int newData) {
  Node * newNode;
  newNode = new Node;
  newNode - > data = newData;
  newNode - > next = nullptr;
  while (h != nullptr) {
    if (h - > next == nullptr) {
      h - > next = newNode;
      break;
    }
    h = h - > next;
  }
}

void printlist(Node * h) {
  while (h - > next != nullptr) { //or h!=0
    cout << h - > data << endl;
    h = h - > next;
  }
}

int main() {
  Node * head;
  Node * second;
  Node * third;
  head = new Node;
  second = new Node;
  third = new Node;
  head - > data = 1;
  head - > next = second;
  second - > data = 2;
  second - > next = third;
  third - > data = 3;
  third - > next = nullptr;
  int newData = 4;
  pushend(head, newData);
  printlist(head);
}