**     linked list passed as the second argument (pWin)
**
** Append the node to output expression-list (*ppSub). And replace it
** with a TK_COLUMN that reads the (N-1)th element of table 
** pWin->iEphCsr, where N is the number of elements in (*ppSub) after
** appending the new one.
*/
static int selectWindowRewriteEList(
  Parse *pParse, 
  Window *pWin,
  ExprList *pEList,               /* Rewrite expressions in this list */
  ExprList **ppSub                /* IN/OUT: Sub-select expression-list */
){
  Walker sWalker;
  WindowRewrite sRewrite;
  int rc;

  memset(&sWalker, 0, sizeof(Walker));
  memset(&sRewrite, 0, sizeof(WindowRewrite));

  sRewrite.pSub = *ppSub;
  sRewrite.pWin = pWin;

  sWalker.pParse = pParse;
  sWalker.xExprCallback = selectWindowRewriteExprCb;
  sWalker.xSelectCallback = selectWindowRewriteSelectCb;
  sWalker.u.pRewrite = &sRewrite;

  rc = sqlite3WalkExprList(&sWalker, pEList);

  *ppSub = sRewrite.pSub;
  return rc;
}

/*
** Append a copy of each expression in expression-list pAppend to
** expression list pList. Return a pointer to the result list.
*/
static ExprList *exprListAppendList(
................................................................................
    p->pHaving = 0;

    /* Assign a cursor number for the ephemeral table used to buffer rows.
    ** The OpenEphemeral instruction is coded later, after it is known how
    ** many columns the table will have.  */
    pMWin->iEphCsr = pParse->nTab++;

    rc = selectWindowRewriteEList(pParse, pMWin, p->pEList, &pSublist);
    if( rc ) return rc;
    rc = selectWindowRewriteEList(pParse, pMWin, p->pOrderBy, &pSublist);
    if( rc ) return rc;
    pMWin->nBufferCol = (pSublist ? pSublist->nExpr : 0);

    /* Create the ORDER BY clause for the sub-select. This is the concatenation
    ** of the window PARTITION and ORDER BY clauses. Append the same 
    ** expressions to the sub-select expression list. They are required to
    ** figure out where boundaries for partitions and sets of peer rows.  */
    pSort = sqlite3ExprListDup(db, pMWin->pPartition, 0);

**     linked list passed as the second argument (pWin)
**
** Append the node to output expression-list (*ppSub). And replace it
** with a TK_COLUMN that reads the (N-1)th element of table 
** pWin->iEphCsr, where N is the number of elements in (*ppSub) after
** appending the new one.
*/
static void selectWindowRewriteEList(
  Parse *pParse, 
  Window *pWin,
  ExprList *pEList,               /* Rewrite expressions in this list */
  ExprList **ppSub                /* IN/OUT: Sub-select expression-list */
){
  Walker sWalker;
  WindowRewrite sRewrite;


  memset(&sWalker, 0, sizeof(Walker));
  memset(&sRewrite, 0, sizeof(WindowRewrite));

  sRewrite.pSub = *ppSub;
  sRewrite.pWin = pWin;

  sWalker.pParse = pParse;
  sWalker.xExprCallback = selectWindowRewriteExprCb;
  sWalker.xSelectCallback = selectWindowRewriteSelectCb;
  sWalker.u.pRewrite = &sRewrite;

  (void)sqlite3WalkExprList(&sWalker, pEList);

  *ppSub = sRewrite.pSub;

}

/*
** Append a copy of each expression in expression-list pAppend to
** expression list pList. Return a pointer to the result list.
*/
static ExprList *exprListAppendList(
................................................................................
    p->pHaving = 0;

    /* Assign a cursor number for the ephemeral table used to buffer rows.
    ** The OpenEphemeral instruction is coded later, after it is known how
    ** many columns the table will have.  */
    pMWin->iEphCsr = pParse->nTab++;

    selectWindowRewriteEList(pParse, pMWin, p->pEList, &pSublist);

    selectWindowRewriteEList(pParse, pMWin, p->pOrderBy, &pSublist);

    pMWin->nBufferCol = (pSublist ? pSublist->nExpr : 0);

    /* Create the ORDER BY clause for the sub-select. This is the concatenation
    ** of the window PARTITION and ORDER BY clauses. Append the same 
    ** expressions to the sub-select expression list. They are required to
    ** figure out where boundaries for partitions and sets of peer rows.  */
    pSort = sqlite3ExprListDup(db, pMWin->pPartition, 0);

    lead(y, 2) OVER win, 
    lead(y, 3, 'default') OVER win
  FROM t1
  WINDOW win AS (ORDER BY x)
} {
  4 6 8   6 8 10   8 10 default   10 {} default   {} {} default
}






finish_test

    lead(y, 2) OVER win, 
    lead(y, 3, 'default') OVER win
  FROM t1
  WINDOW win AS (ORDER BY x)
} {
  4 6 8   6 8 10   8 10 default   10 {} default   {} {} default
}

do_execsql_test 7.3 {
  SELECT row_number() OVER (ORDER BY x) FROM t1
} {1 2 3 4 5}


finish_test

           min(d) OVER win
    FROM t1
    WINDOW win AS (ORDER BY a)
  }
} -test {
  faultsim_test_result {0 {1 1 1 1 4 4 {} 8 {} 4 4 2 2 2 1 4 8 8 12 4 8 4 3 3 3 2 4 12 8 {} 8 12 4}}
}














finish_test

           min(d) OVER win
    FROM t1
    WINDOW win AS (ORDER BY a)
  }
} -test {
  faultsim_test_result {0 {1 1 1 1 4 4 {} 8 {} 4 4 2 2 2 1 4 8 8 12 4 8 4 3 3 3 2 4 12 8 {} 8 12 4}}
}

do_faultsim_test 2 -faults oom-* -prep {
  faultsim_restore_and_reopen
} -body {
  execsql {
    SELECT min(d) OVER win, max(d) OVER win
    FROM t1
    WINDOW win AS (ORDER BY a RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
  }
} -test {
  faultsim_test_result {0 {4 12 8 12 12 12}}
}


finish_test