SQLite

      Expr ifNullRow;
      assert( pSubst->pEList!=0 && iColumn<pSubst->pEList->nExpr );
      assert( pExpr->pRight==0 );
      if( sqlite3ExprIsVector(pCopy) ){
        sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
      }else{
        sqlite3 *db = pSubst->pParse->db;
        if( pSubst->isOuterJoin ){
          memset(&ifNullRow, 0, sizeof(ifNullRow));
          ifNullRow.op = TK_IF_NULL_ROW;
          ifNullRow.pLeft = pCopy;
          ifNullRow.iTable = pSubst->iNewTable;
          ifNullRow.iColumn = -99;
          ifNullRow.flags = EP_IfNullRow;
          pCopy = &ifNullRow;

  SELECT ccc, ccc IS NULL AS ddd FROM t1 LEFT JOIN v2;
} {{} 1}
optimization_control db query-flattener 0
do_execsql_test 9.11 {
  SELECT ccc, ccc IS NULL AS ddd FROM t1 LEFT JOIN v2;
} {{} 1}

# 2023-03-01 https://sqlite.org/forum/forumpost/26387ea7ef
# When flattening a VIEW which is the RHS of a LEFT JOIN, always put
# an TK_IF_NULL_ROW operator on all accesses, even TK_COLUMN nodes, since
# the TK_COLUMN might reference an outer subquery.
#
reset_db
db null NULL
do_execsql_test 10.1 {
  CREATE TABLE t1 (x INTEGER);
  INSERT INTO t1 VALUES(1);   -- Some true value
  CREATE TABLE t2 (z TEXT);
  INSERT INTO t2 VALUES('some value');
  CREATE TABLE t3(w TEXT);
  INSERT INTO t3 VALUES('some other value');
}
do_execsql_test 10.2 {
  SELECT (
    SELECT 1 FROM t2 LEFT JOIN (SELECT x AS v FROM t3) ON 500=v WHERE (v OR FALSE)
  ) FROM t1;
} NULL
do_execsql_test 10.3 {
  SELECT (
    SELECT 1 FROM t2 LEFT JOIN (SELECT x AS v FROM t3) ON 500=v WHERE (v)
  ) FROM t1;
} NULL
optimization_control db all 0
do_execsql_test 10.4 {
  SELECT (
    SELECT 1 FROM t2 LEFT JOIN (SELECT x AS v FROM t3) ON 500=v WHERE (v OR FALSE)
  ) FROM t1;
} NULL

finish_test