database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

Fixed bug #24653.

Browse Source 
The bug report has demonstrated the following two problems.
1. If an ORDER/GROUP BY list includes a constant expression being 
optimized away and, at the same time, containing single-row
subselects that return more that one row, no error is reported.
Strictly speaking the standard allows to ignore error in this case.
Yet, now a corresponding fatal error is reported in this case.
2. If a query requires sorting by expressions containing single-row
subselects that, however, return more than one row, then the execution
of the query may cause a server crash. 
To fix this some code has been added that blocks execution of a subselect
item in case of a fatal error in the method Item_subselect::exec.
This commit is contained in:
igor@olga.mysql.com
2007-01-25 18:44:35 -08:00
parent 9659c11b6e
commit 36df33d80a
10 changed files with 174 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
sql/sql_select.cc
View File

@ -644,6 +644,13 @@ JOIN::optimize()
{
ORDER *org_order= order;
order=remove_const(this, order,conds,1, &simple_order);
if (thd->net.report_error)
{
error= 1;
DBUG_PRINT("error",("Error from remove_const"));
DBUG_RETURN(1);
}
/*
If we are using ORDER BY NULL or ORDER BY const_expression,
return result in any order (even if we are using a GROUP BY)
@ -747,6 +754,12 @@ JOIN::optimize()
group_list= remove_const(this, (old_group_list= group_list), conds,
rollup.state == ROLLUP::STATE_NONE,
&simple_group);
if (thd->net.report_error)
{
error= 1;
DBUG_PRINT("error",("Error from remove_const"));
DBUG_RETURN(1);
}
if (old_group_list && !group_list)
select_distinct= 0;
}
@ -763,6 +776,12 @@ JOIN::optimize()
{
group_list= procedure->group= remove_const(this, procedure->group, conds,
1, &simple_group);
if (thd->net.report_error)
{
error= 1;
DBUG_PRINT("error",("Error from remove_const"));
DBUG_RETURN(1);
}
calc_group_buffer(this, group_list);
}
@ -4428,6 +4447,8 @@ remove_const(JOIN *join,ORDER *first_order, COND *cond,
*simple_order=0; // Must do a temp table to sort
else if (!(order_tables & not_const_tables))
{
if (order->item[0]->with_subselect)
order->item[0]->val_str(&order->item[0]->str_value);
DBUG_PRINT("info",("removing: %s", order->item[0]->full_name()));
continue; // skip const item
}