1 files changed, 60 insertions, 1 deletions
diff --git a/mysql-test/main/mysql_upgrade.result b/mysql-test/main/mysql_upgrade.result
index 7d01a428ca1..93888ba805f 100644
--- a/mysql-test/main/mysql_upgrade.result
+++ b/mysql-test/main/mysql_upgrade.result
@@ -826,7 +826,66 @@ DROP USER 'user3'@'%';
 update mysql.db set Delete_history_priv='Y' where db like 'test%';
 drop table mysql.global_priv;
 rename table mysql.global_priv_bak to mysql.global_priv;
-# End of 10.3 tests
+#
+# MDEV-16735 Upgrades only work if 'alter_algorithm' is 'DEFAULT'
+# or 'COPY'. Test that the session value 'DEFAULT' in mysql_upgrade
+# properly overrides the potentially incompatible global value.
+#
+SET GLOBAL alter_algorithm='INPLACE';
+SHOW GLOBAL VARIABLES LIKE 'alter_algorithm';
+Variable_name	Value
+alter_algorithm	INPLACE
+Phase 1/7: Checking and upgrading mysql database
+Processing databases
+mysql
+mysql.column_stats                                 OK
+mysql.columns_priv                                 OK
+mysql.db                                           OK
+mysql.event                                        OK
+mysql.func                                         OK
+mysql.global_priv                                  OK
+mysql.gtid_slave_pos                               OK
+mysql.help_category                                OK
+mysql.help_keyword                                 OK
+mysql.help_relation                                OK
+mysql.help_topic                                   OK
+mysql.index_stats                                  OK
+mysql.innodb_index_stats                           OK
+mysql.innodb_table_stats                           OK
+mysql.plugin                                       OK
+mysql.proc                                         OK
+mysql.procs_priv                                   OK
+mysql.proxies_priv                                 OK
+mysql.roles_mapping                                OK
+mysql.servers                                      OK
+mysql.table_stats                                  OK
+mysql.tables_priv                                  OK
+mysql.time_zone                                    OK
+mysql.time_zone_leap_second                        OK
+mysql.time_zone_name                               OK
+mysql.time_zone_transition                         OK
+mysql.time_zone_transition_type                    OK
+mysql.transaction_registry                         OK
+Phase 2/7: Installing used storage engines... Skipped
+Phase 3/7: Fixing views
+mysql.user                                         OK
+Phase 4/7: Running 'mysql_fix_privilege_tables'
+Phase 5/7: Fixing table and database names
+Phase 6/7: Checking and upgrading tables
+Processing databases
+information_schema
+mtr
+mtr.global_suppressions                            OK
+mtr.test_suppressions                              OK
+performance_schema
+test
+Phase 7/7: Running 'FLUSH PRIVILEGES'
+OK
+SET GLOBAL alter_algorithm=DEFAULT;
+SHOW GLOBAL VARIABLES LIKE 'alter_algorithm';
+Variable_name	Value
+alter_algorithm	DEFAULT
+End of 10.3 tests
 # switching from mysql.global_priv to mysql.user
 drop view mysql.user_bak;
 create user 'user3'@'localhost' identified with mysql_native_password as password('a_password');