Making an int into a char* (string) Part 2.1

I realized afterwards that I forgot to ensure my function would work with negative numbers as well as positive.  I have added a few lines to remedy this.

int my_itoa(char* str, int num) {
  int i, neg = 0, length = 1, x = 0;
  
  if(str != NULL) {
    if(num < 0) {
      neg = num;
      num = -num;
    }
    for(i = num / 10; i > 0 ; i /= 10) {
      length++;
    }
    for(i = length - 1; i >= 0; i--) {
      if(neg < 0) {
        str[0] = '-';
        neg = 1;
      }
      str[i + neg] = (num % 10) + '0';
      num /= 10;
    }
    str[length + neg] = '\0';
    x = 1;
  }
  return x;
}