SQLite

    }
  }
  return pRet;
}
#else
# define withDup(x,y) 0
#endif

#ifndef SQLITE_OMIT_WINDOWFUNC
/*
** The gatherSelectWindows() procedure and its helper routine
** gatherSelectWindowsCallback() are used to scan all the expressions
** an a newly duplicated SELECT statement and gather all of the Window
** objects found there, assembling them onto the linked list at Select->pWin.
*/
static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_FUNCTION && pExpr->y.pWin!=0 ){
    assert( ExprHasProperty(pExpr, EP_WinFunc) );
    pExpr->y.pWin->pNextWin = pWalker->u.pSelect->pWin;
    pWalker->u.pSelect->pWin = pExpr->y.pWin;
  }
  return WRC_Continue;
}
static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){
  return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune;
}
static void gatherSelectWindows(Select *p){
  Walker w;
  w.xExprCallback = gatherSelectWindowsCallback;
  w.xSelectCallback = gatherSelectWindowsSelectCallback;
  w.xSelectCallback2 = 0;
  w.u.pSelect = p;
  sqlite3WalkSelect(&w, p);
}
#endif


/*
** The following group of routines make deep copies of expressions,
** expression lists, ID lists, and select statements.  The copies can
** be deleted (by being passed to their respective ...Delete() routines)
** without effecting the originals.
**

    pNew->addrOpenEphm[0] = -1;
    pNew->addrOpenEphm[1] = -1;
    pNew->nSelectRow = p->nSelectRow;
    pNew->pWith = withDup(db, p->pWith);
#ifndef SQLITE_OMIT_WINDOWFUNC
    pNew->pWin = 0;
    pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn);
    if( p->pWin ) gatherSelectWindows(pNew);
#endif
    pNew->selId = p->selId;
    *pp = pNew;
    pp = &pNew->pPrior;
    pNext = pNew;
  }

        if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){
          memset(&ifNullRow, 0, sizeof(ifNullRow));
          ifNullRow.op = TK_IF_NULL_ROW;
          ifNullRow.pLeft = pCopy;
          ifNullRow.iTable = pSubst->iNewTable;
          pCopy = &ifNullRow;
        }
        testcase( ExprHasProperty(pCopy, EP_Subquery) );
        pNew = sqlite3ExprDup(db, pCopy, 0);
        if( pNew && pSubst->isLeftJoin ){
          ExprSetProperty(pNew, EP_CanBeNull);
        }
        if( pNew && ExprHasProperty(pExpr,EP_FromJoin) ){
          pNew->iRightJoinTable = pExpr->iRightJoinTable;
          ExprSetProperty(pNew, EP_FromJoin);

      for(i=0; i<pOrderBy->nExpr; i++){
        pOrderBy->a[i].u.x.iOrderByCol = 0;
      }
      assert( pParent->pOrderBy==0 );
      pParent->pOrderBy = pOrderBy;
      pSub->pOrderBy = 0;
    }
    pWhere = pSub->pWhere;
    pSub->pWhere = 0;
    if( isLeftJoin>0 ){
      setJoinExpr(pWhere, iNewParent);
    }
    pParent->pWhere = sqlite3ExprAnd(db, pWhere, pParent->pWhere);
    if( db->mallocFailed==0 ){
      SubstContext x;
      x.pParse = pParse;

Window *sqlite3WindowDup(sqlite3 *db, Expr *pOwner, Window *p){
  Window *pNew = 0;
  if( ALWAYS(p) ){
    pNew = sqlite3DbMallocZero(db, sizeof(Window));
    if( pNew ){
      pNew->zName = sqlite3DbStrDup(db, p->zName);
      pNew->pFilter = sqlite3ExprDup(db, p->pFilter, 0);
      pNew->pFunc = p->pFunc;
      pNew->pPartition = sqlite3ExprListDup(db, p->pPartition, 0);
      pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, 0);
      pNew->eType = p->eType;
      pNew->eEnd = p->eEnd;
      pNew->eStart = p->eStart;
      pNew->pStart = sqlite3ExprDup(db, p->pStart, 0);
      pNew->pEnd = sqlite3ExprDup(db, p->pEnd, 0);

do_execsql_test 13.5 {
  SELECT a, rank() OVER(ORDER BY b) FROM t1
    INTERSECT 
  SELECT a, rank() OVER(ORDER BY b DESC) FROM t1;
} {
}

# 2018-12-06
# https://www.sqlite.org/src/info/f09fcd17810f65f7
# Assertion fault when window functions are used.
#
# Root cause is the query flattener invoking sqlite3ExprDup() on
# expressions that contain subqueries with window functions.  The
# sqlite3ExprDup() routine is not making correctly initializing
# Select.pWin field of the subqueries.
#
sqlite3 db :memory:
do_execsql_test 14.0 {
  SELECT * FROM(
    SELECT * FROM (SELECT 1 AS c) WHERE c IN (
        SELECT (row_number() OVER()) FROM (VALUES (0))
    )
  );
} {1}
do_execsql_test 14.1 {
  CREATE TABLE t1(x); INSERT INTO t1(x) VALUES(12345);
  CREATE TABLE t2(c); INSERT INTO t2(c) VALUES(1);
  SELECT y, y+1, y+2 FROM (
    SELECT c IN (
      SELECT (row_number() OVER()) FROM t1
    ) AS y FROM t2
  );
} {1 2 3}

finish_test