diff --git a/src/backend/nodes/list.c b/src/backend/nodes/list.c
index 083538f..fe085d2 100644
*** a/src/backend/nodes/list.c
--- b/src/backend/nodes/list.c
*************** list_copy_tail(const List *oldlist, int 
*** 1250,1290 ****
  }
  
  /*
!  * Sort a list using qsort. A sorted list is built but the cells of the
!  * original list are re-used.  The comparator function receives arguments of
!  * type ListCell **
   */
  List *
  list_qsort(const List *list, list_qsort_comparator cmp)
  {
- 	ListCell   *cell;
- 	int			i;
  	int			len = list_length(list);
  	ListCell  **list_arr;
! 	List	   *new_list;
  
  	if (len == 0)
  		return NIL;
  
  	i = 0;
- 	list_arr = palloc(sizeof(ListCell *) * len);
  	foreach(cell, list)
  		list_arr[i++] = cell;
  
  	qsort(list_arr, len, sizeof(ListCell *), cmp);
  
! 	new_list = (List *) palloc(sizeof(List));
! 	new_list->type = list->type;
! 	new_list->length = len;
! 	new_list->head = list_arr[0];
! 	new_list->tail = list_arr[len - 1];
  
! 	for (i = 0; i < len - 1; i++)
! 		list_arr[i]->next = list_arr[i + 1];
  
! 	list_arr[len - 1]->next = NULL;
  	pfree(list_arr);
! 	return new_list;
  }
  
  /*
--- 1250,1312 ----
  }
  
  /*
!  * Sort a list as though by qsort.
!  *
!  * A new list is built and returned.
!  * The comparator function receives arguments of type ListCell **.
   */
  List *
  list_qsort(const List *list, list_qsort_comparator cmp)
  {
  	int			len = list_length(list);
  	ListCell  **list_arr;
! 	List	   *newlist;
! 	ListCell   *newlist_prev;
! 	ListCell   *cell;
! 	int			i;
  
+ 	/* Empty list is easy */
  	if (len == 0)
  		return NIL;
  
+ 	/* Flatten list cells into an array, so we can use qsort */
+ 	list_arr = (ListCell **) palloc(sizeof(ListCell *) * len);
  	i = 0;
  	foreach(cell, list)
  		list_arr[i++] = cell;
  
  	qsort(list_arr, len, sizeof(ListCell *), cmp);
  
! 	/* Construct new list (this code is much like list_copy) */
! 	newlist = new_list(list->type);
! 	newlist->length = len;
  
! 	/*
! 	 * Copy over the data in the first cell; new_list() has already allocated
! 	 * the head cell itself
! 	 */
! 	newlist->head->data = list_arr[0]->data;
  
! 	newlist_prev = newlist->head;
! 	for (i = 1; i < len; i++)
! 	{
! 		ListCell   *newlist_cur;
! 
! 		newlist_cur = (ListCell *) palloc(sizeof(*newlist_cur));
! 		newlist_cur->data = list_arr[i]->data;
! 		newlist_prev->next = newlist_cur;
! 
! 		newlist_prev = newlist_cur;
! 	}
! 
! 	newlist_prev->next = NULL;
! 	newlist->tail = newlist_prev;
! 
! 	/* Might as well free the workspace array */
  	pfree(list_arr);
! 
! 	check_list_invariants(newlist);
! 	return newlist;
  }
  
  /*