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Bug#24630 Subselect query crashes mysqld

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The crash happens because second filling of the same I_S table happens in
case of subselect with order by. table->sort.io_cache previously allocated
in create_sort_index() is deleted during second filling
(function get_schema_tables_result). There are two places where
I_S table can be filled: JOIN::exec and create_sort_index().
To fix the bug we should check if the table was already filled
in one of these places and skip processing of the table in second.
This commit is contained in:
gluh@mysql.com/eagle.(none)
2007-02-12 16:06:14 +04:00
parent 0583c7c524
commit 47e537b47c
7 changed files with 93 additions and 13 deletions
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28
sql/sql_show.cc
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@ -3938,13 +3938,15 @@ int make_schema_select(THD *thd, SELECT_LEX *sel,
SYNOPSIS
get_schema_tables_result()
join join which use schema tables
executed_place place where I_S table processed
RETURN
FALSE success
TRUE error
*/
bool get_schema_tables_result(JOIN *join)
bool get_schema_tables_result(JOIN *join,
enum enum_schema_table_state executed_place)
{
JOIN_TAB *tmp_join_tab= join->join_tab+join->tables;
THD *thd= join->thd;
@ -3964,14 +3966,24 @@ bool get_schema_tables_result(JOIN *join)
bool is_subselect= (&lex->unit != lex->current_select->master_unit() &&
lex->current_select->master_unit()->item);
/*
The schema table is already processed and
the statement is not a subselect.
So we don't need to handle this table again.
If schema table is already processed and
the statement is not a subselect then
we don't need to fill this table again.
If schema table is already processed and
schema_table_state != executed_place then
table is already processed and
we should skip second data processing.
*/
if (table_list->is_schema_table_processed && !is_subselect)
if (table_list->schema_table_state &&
(!is_subselect || table_list->schema_table_state != executed_place))
continue;
if (is_subselect) // is subselect
/*
if table is used in a subselect and
table has been processed earlier with the same
'executed_place' value then we should refresh the table.
*/
if (table_list->schema_table_state && is_subselect)
{
table_list->table->file->extra(HA_EXTRA_NO_CACHE);
table_list->table->file->extra(HA_EXTRA_RESET_STATE);
@ -3988,10 +4000,10 @@ bool get_schema_tables_result(JOIN *join)
{
result= 1;
join->error= 1;
table_list->is_schema_table_processed= TRUE;
table_list->schema_table_state= executed_place;
break;
}
table_list->is_schema_table_processed= TRUE;
table_list->schema_table_state= executed_place;
}
}
thd->no_warnings_for_error= 0;