set @save_session_track_system_variables=@@session_track_system_variables;
SELECT @@session.character_set_connection;
@@session.character_set_connection
latin1
SET @@session.session_track_system_variables='character_set_connection';
# tracking info on
SET NAMES 'utf8';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- character_set_connection
-- utf8mb3

SET NAMES 'big5';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- character_set_connection
-- big5

# tracking info on once
SET NAMES 'utf8';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- character_set_connection
-- utf8mb3

SET NAMES 'big5';
# tracking info on
SET NAMES 'utf8';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- character_set_connection
-- utf8mb3

# tracking info off once
SET NAMES 'big5';
SET @@session.session_track_system_variables= @save_session_track_system_variables;
#
# MDEV-22504: session tracking return incorrectly long traking data
#
set @save_optimizer_switch=@@optimizer_switch;
SET @@session.session_track_system_variables='optimizer_switch';
set optimizer_switch='index_merge=off,index_merge_union=off,index_merge_sort_union=off,index_merge_intersection=off,index_merge_sort_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=on,mrr_cost_based=on,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=on,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- optimizer_switch
-- index_merge=off,index_merge_union=off,index_merge_sort_union=off,index_merge_intersection=off,index_merge_sort_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=on,mrr_cost_based=on,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=on,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=on,cset_narrowing=off

Warnings:
Warning	1681	'engine_condition_pushdown=on' is deprecated and will be removed in a future release
set @@optimizer_switch=@save_optimizer_switch;
SET @@session.session_track_system_variables= @save_session_track_system_variables;
# End of 10.2 tests
#
# MDEV-22134 handle_fatal_signal (sig=11) in __strlen_avx2 on START
# SLAVE | Assertion
# `global_system_variables.session_track_system_variables' failed in
# Session_sysvars_tracker::init | *** buffer overflow detected ***
# (on optimized builds)
#
SET @@GLOBAL.session_track_system_variables=NULL;
ERROR 42000: Variable 'session_track_system_variables' can't be set to the value of 'NULL'
SET SESSION session_track_system_variables=NULL;
ERROR 42000: Variable 'session_track_system_variables' can't be set to the value of 'NULL'
# End of 10.3 tests
#
# MDEV-25237: crash after setting global session_track_system_variables
# to an invalid value
#
SET GLOBAL session_track_system_variables='a';
ERROR HY000: Unknown system variable 'a'
SET GLOBAL event_scheduler=1;
# check that value really returns as it was
set GLOBAL session_track_system_variables='character_set_connection';
SET GLOBAL session_track_system_variables='a';
ERROR HY000: Unknown system variable 'a'
connect  con,localhost,root,,test;
SET NAMES 'utf8';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- character_set_connection
-- utf8mb3

SET NAMES 'big5';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- character_set_connection
-- big5

select @@session_track_system_variables;
@@session_track_system_variables
character_set_connection
connection default;
disconnect con;
SET GLOBAL session_track_system_variables=default;
SET GLOBAL event_scheduler=default;
# End of 10.4 test
#
# MDEV-16470 - Session user variables tracker
#
# End of 10.5 tests
#
# MDEV-31746 Problems with tx_isolation after MDEV-21921
#
# tracking info on
SET session_track_system_variables='max_insert_delayed_threads';
SET max_delayed_threads=0;
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- max_insert_delayed_threads
-- 0

SET @@max_delayed_threads=0;
SET SESSION max_delayed_threads=0;
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- max_insert_delayed_threads
-- 0

SET session_track_system_variables='max_delayed_threads';
SET max_insert_delayed_threads=@@global.max_delayed_threads;
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- max_delayed_threads
-- 20

SET session_track_system_variables='tx_isolation';
SET @@session.tx_isolation='READ-COMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- READ-COMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION tx_isolation='READ-UNCOMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- READ-UNCOMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION transaction_isolation='REPEATABLE-READ';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- REPEATABLE-READ

Track 2, get 2
SET session_track_system_variables='tx_isolation,transaction_isolation';
select @@session_track_system_variables;
@@session_track_system_variables
tx_isolation
SET @@session.tx_isolation='READ-COMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- READ-COMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION tx_isolation='READ-UNCOMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- READ-UNCOMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION transaction_isolation='REPEATABLE-READ';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- REPEATABLE-READ

SET session_track_system_variables='transaction_isolation';
SET @@session.tx_isolation='READ-COMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- transaction_isolation
-- READ-COMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION tx_isolation='READ-UNCOMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- transaction_isolation
-- READ-UNCOMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION transaction_isolation='REPEATABLE-READ';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- transaction_isolation
-- REPEATABLE-READ

SET session_track_system_variables='tx_isolation,transaction_isolation,tx_isolation';
SELECT @@session_track_system_variables;
@@session_track_system_variables
tx_isolation
SET @@session.tx_isolation='READ-COMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- READ-COMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION tx_isolation='READ-UNCOMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- READ-UNCOMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION transaction_isolation='REPEATABLE-READ';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- REPEATABLE-READ

accumulate as we encounter duplicates
SET session_track_system_variables='*';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- session_track_system_variables
-- *

SET @@session.tx_isolation='READ-COMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- READ-COMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION tx_isolation='READ-UNCOMMITTED';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- READ-UNCOMMITTED

Warnings:
Warning	1287	'@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead
SET SESSION transaction_isolation='REPEATABLE-READ';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- tx_isolation
-- REPEATABLE-READ

# End of 11.1 tests