void sqlite3ExprAttachSubtrees(
  sqlite3 *db,
  Expr *pRoot,
  Expr *pLeft,
  Expr *pRight
){
  if( pRoot==0 ){
    assert( db->mallocFailed );
    sqlite3ExprDelete(db, pLeft);
    sqlite3ExprDelete(db, pRight);
  }else{
    if( pRight ){
      pRoot->pRight = pRight;
      pRoot->flags |= EP_Propagate & pRight->flags;
    }
    if( pLeft ){
      pRoot->pLeft = pLeft;
      pRoot->flags |= EP_Propagate & pLeft->flags;
    }
    exprSetHeight(pRoot);
  }
}
void sqlite3ExprAttachSubtrees(
  sqlite3 *db,
  Expr *pRoot,
  Expr *pLeft,
  Expr *pRight
){
  if( pRoot==0 ){
    assert( db->mallocFailed );
    sqlite3ExprDelete(db, pLeft);
    sqlite3ExprDelete(db, pRight);
  }else{
    if( pRight ){
      pRoot->pRight = pRight;
      pRoot->flags |= EP_Propagate & pRight->flags;
    }
    if( pLeft ){
      pRoot->pLeft = pLeft;
      pRoot->flags |= EP_Propagate & pLeft->flags;
    }
    exprSetHeight(pRoot);
  }
}