}

/*
** Load the record ID rid and up to N-1 closest descendants into
** the "ok" table.
*/
void compute_descendants(int rid, int N){
  Bag seen;
  PQueue queue;
  Stmt ins;
  Stmt q;

  bag_init(&seen);
  pqueuex_init(&queue);
  bag_insert(&seen, rid);
  pqueuex_insert(&queue, rid, 0.0, 0);
  db_prepare(&ins, "INSERT OR IGNORE INTO ok VALUES(:rid)");
  db_multi_exec(
    "WITH RECURSIVE"
    "  dx(rid,mtime) AS ("
    "     SELECT %d, 0"
    "     UNION"
    "     SELECT plink.cid, plink.mtime FROM dx, plink"
    "      WHERE plink.pid=dx.rid"
    "      ORDER BY 2"
    "  )"
    "INSERT OR IGNORE INTO ok SELECT rid FROM dx LIMIT %d",
  db_prepare(&q, "SELECT cid, mtime FROM plink WHERE pid=:rid");
  while( (N--)>0 && (rid = pqueuex_extract(&queue, 0))!=0 ){
    db_bind_int(&ins, ":rid", rid);
    db_step(&ins);
    db_reset(&ins);
    db_bind_int(&q, ":rid", rid);
    while( db_step(&q)==SQLITE_ROW ){
      int pid = db_column_int(&q, 0);
      double mtime = db_column_double(&q, 1);
      if( bag_insert(&seen, pid) ){
        pqueuex_insert(&queue, pid, mtime, 0);
    rid, N
      }
    }
    db_reset(&q);
  );
  }
  bag_clear(&seen);
  pqueuex_clear(&queue);
  db_finalize(&ins);
  db_finalize(&q);
}

/*
** COMMAND: descendants*
**
** Usage: %fossil descendants ?CHECKIN? ?OPTIONS?
**