Sort a linked list

This is not an efficient way to sort a linked list (runs in O(N²), but it works when you don't care about efficiency (sometimes homework for a class). This code sorts a linked list in place with bubble sort.

do {
 num_swaps = 0;
 cur = q->head;
 while (cur) {
  if (cur->next) {
   res = queue_element_compare(cur->e, cur->next->e);
   if (res == 1) {
    temp = cur->e;
    cur->e = cur->next->e;
    cur->next->e = temp;
    num_swaps++;
   }
  }
  cur = cur->next;
 }
} while (num_swaps > 0);

queue_element_compare returns 0 on equal, 1 if e1 > e2 and -1 when e1 < e2.