Bug #20784 Uninitialized memory in update on table with PK not on first column

- partial backport of code from 5.1, do cot compare_record for engines that do not read all columns during update
parent c8b65bb3
......@@ -4575,7 +4575,8 @@ ha_ndbcluster::ha_ndbcluster(TABLE *table_arg):
HA_NO_PREFIX_CHAR_KEYS |
HA_NEED_READ_RANGE_BUFFER |
HA_CAN_GEOMETRY |
HA_CAN_BIT_FIELD),
HA_CAN_BIT_FIELD |
HA_PARTIAL_COLUMN_READ),
m_share(0),
m_use_write(FALSE),
m_ignore_dup_key(FALSE),
......
......@@ -57,6 +57,7 @@
see mi_rsame/heap_rsame/myrg_rsame
*/
#define HA_READ_RND_SAME (1 << 0)
#define HA_PARTIAL_COLUMN_READ (1 << 1) /* read may not return all columns */
#define HA_TABLE_SCAN_ON_INDEX (1 << 2) /* No separate data/index file */
#define HA_REC_NOT_IN_SEQ (1 << 3) /* ha_info don't return recnumber;
It returns a position to ha_r_rnd */
......
......@@ -120,6 +120,7 @@ int mysql_update(THD *thd,
bool using_limit= limit != HA_POS_ERROR;
bool safe_update= thd->options & OPTION_SAFE_UPDATES;
bool used_key_is_modified, transactional_table;
bool can_compare_record;
int res;
int error;
uint used_index= MAX_KEY;
......@@ -433,6 +434,13 @@ int mysql_update(THD *thd,
(MODE_STRICT_TRANS_TABLES |
MODE_STRICT_ALL_TABLES)));
/*
We can use compare_record() to optimize away updates if
the table handler is returning all columns
*/
can_compare_record= !(table->file->table_flags() &
HA_PARTIAL_COLUMN_READ);
while (!(error=info.read_record(&info)) && !thd->killed)
{
if (!(select && select->skip_record()))
......@@ -445,7 +453,7 @@ int mysql_update(THD *thd,
found++;
if (compare_record(table, query_id))
if (!can_compare_record || compare_record(table, query_id))
{
if ((res= table_list->view_check_option(thd, ignore)) !=
VIEW_CHECK_OK)
......@@ -1248,8 +1256,15 @@ bool multi_update::send_data(List<Item> &not_used_values)
uint offset= cur_table->shared;
table->file->position(table->record[0]);
/*
We can use compare_record() to optimize away updates if
the table handler is returning all columns
*/
if (table == table_to_update)
{
bool can_compare_record;
can_compare_record= !(table->file->table_flags() &
HA_PARTIAL_COLUMN_READ);
table->status|= STATUS_UPDATED;
store_record(table,record[1]);
if (fill_record_n_invoke_before_triggers(thd, *fields_for_table[offset],
......@@ -1259,7 +1274,7 @@ bool multi_update::send_data(List<Item> &not_used_values)
DBUG_RETURN(1);
found++;
if (compare_record(table, thd->query_id))
if (!can_compare_record || compare_record(table, thd->query_id))
{
int error;
if ((error= cur_table->view_check_option(thd, ignore)) !=
......@@ -1376,6 +1391,7 @@ int multi_update::do_updates(bool from_send_error)
for (cur_table= update_tables; cur_table; cur_table= cur_table->next_local)
{
byte *ref_pos;
bool can_compare_record;
table = cur_table->table;
if (table == table_to_update)
......@@ -1402,6 +1418,9 @@ int multi_update::do_updates(bool from_send_error)
if ((local_error = tmp_table->file->ha_rnd_init(1)))
goto err;
can_compare_record= !(table->file->table_flags() &
HA_PARTIAL_COLUMN_READ);
ref_pos= (byte*) tmp_table->field[0]->ptr;
for (;;)
{
......@@ -1431,7 +1450,7 @@ int multi_update::do_updates(bool from_send_error)
TRG_ACTION_BEFORE, TRUE))
goto err2;
if (compare_record(table, thd->query_id))
if (!can_compare_record || compare_record(table, thd->query_id))
{
if ((local_error=table->file->update_row(table->record[1],
table->record[0])))
......
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