Thread: stack underflow issue

I am writing an N-queens problem using stacks in C. I am only doing boards of size 4 thru 8. I initially had my prog displaying the first solution for boards of those sizes, however, i needed it to display all solutions. When i finally got it to display all solutions, it would get to the first non-solution and instead of jumping out would print the non-solution over and over until i ^C to get out. So it is not doing that any more but now i am popping an empty stack somewhere in my program. I'm pretty sure which function it is and I think I need to add code, not change something i already have, but i have been racking my brain all night and getting nothing. Is there anyone who can help me. I think i am probalby missing one line of code here somewhere but can't figure out what it is. This is my fillBoard function (I thinkthat is where i'm missing something ):

Code:

void FillBoard(STACK *currSolution, STACK *lastSolution, int BoardSize)
{

  int row;
  int col;
  int board[9][9] = {{0}};  /*0 no queens: 1 queen*/

  ELEMENT *place;
  place = (ELEMENT *)malloc(sizeof(ELEMENT));



  if(emptyStack(lastSolution))
  {
    row = 0;
    col = -1;
  }
  else
  {
    while(!emptyStack(lastSolution))
    {
      pop(lastSolution, place);
      push(currSolution, *place);
      board[place->row][place->col] = 1;
      row = place->row;
      col = place->col;
    }
    pop(currSolution, place);
    board[row][col] = 0;

    if( col == BoardSize )
    {
      pop(currSolution, place);
      row = place->row;
      col = place->col;
      board[row][col] = 0;
    }
  }

  while(row < BoardSize)
  {
     while(col < BoardSize && row < BoardSize)
     {
       col++;

       if(!guarded(board, row, col, BoardSize))
       {
         board[row][col] = 1;

         place->row = row;
         place->col = col;

         push(currSolution, *place);

         row++;
         col = -1;
       }
       while(col >= BoardSize - 1)
       {
          pop(currSolution,place);
          row = place->row;
          col = place->col;
          board[row][col] = 0;
       }
     }
  }
  free(place);
  return;
}