MDEV-22249 Upgrade testing between major versions in MTR

mysql-test/include/load_dump_and_upgrade.inc

+--source include/have_innodb.inc
+
+# ==== Usage ====
+#
+# [--let $old_version= 10.2]
+# --source include/load_dump_and_upgrade.inc
+
+# Dumps stored in std_data as mysql_database_<old_version>.dump
+# were pre-created by running mysqldump for `mysql` database
+# on a freshly boostrapped instance of the corresponding version.
+# On 10.4 the local root was additionally given an empty password,
+# to avoid using unix_socket.
+
+# Backup the existing mysql schema, to restore it later
+--exec $MYSQL_DUMP mysql > $MYSQL_TMP_DIR/mysql_database_backup
+
+--echo #
+--echo # Upgrade from version $old_version
+--echo #
+
+# Workaround for MDEV-22127 (can't import database dump created before 10.4)
+# The most universal workaround suggested in the item is running
+#   DROP TABLE IF EXISTS `mysql`.`global_priv`;
+#   DROP VIEW IF EXISTS `mysql`.`user`;
+# before the upgrade. For this test, it is better than creating the dumps
+# with --add-drop-database, because
+# a) it won't require re-creating the dump when the bug is fixed;
+# b) it won't hide possible unrelated problems;
+# c) add-drop-database doesn't work with logging into tables enabled (MDEV-4875 and more)
+
+--exec $MYSQL -e "DROP TABLE IF EXISTS mysql.global_priv; DROP VIEW IF EXISTS mysql.user"
+
+--echo # Loading dump of $old_version mysql schema
+--exec $MYSQL mysql < $MYSQLTEST_VARDIR/std_data/mysql_database_$old_version.dump
+
+--echo # Running mysql_upgrade
+--exec $MYSQL_UPGRADE --verbose > $MYSQL_TMP_DIR/upgrade.log
+
+--echo # Checking that mysql.user is accessible and returns some data
+SELECT COUNT(*) > 0 AS `mysql.user has data` FROM mysql.user;
+
+# Restore the backup of mysql schema
+--exec $MYSQL mysql < $MYSQL_TMP_DIR/mysql_database_backup
+
+--let $ddir= `select @@datadir`
+
+# It will fail if the file doesn't exist, which is good,
+# which is an extra check that it was written
+--remove_file $ddir/mysql_upgrade_info

mysql-test/main/mysql_upgrade.result

@@ -643,3 +643,62 @@ count(*)
 drop table mysql.global_priv;
 rename table mysql.global_priv_bak to mysql.global_priv;
 # End of 10.4 tests
+#
+# Check that mysql_upgrade can be run on mysqldump
+# of mysql schema from previous versions
+#
+call mtr.add_suppression("innodb_table_stats has length mismatch in the column name table_name");
+#
+# Upgrade from version 5.5
+#
+# Loading dump of 5.5 mysql schema
+# Running mysql_upgrade
+# Checking that mysql.user is accessible and returns some data
+SELECT COUNT(*) > 0 AS `mysql.user has data` FROM mysql.user;
+mysql.user has data
+1
+#
+# Upgrade from version 10.0
+#
+# Loading dump of 10.0 mysql schema
+# Running mysql_upgrade
+# Checking that mysql.user is accessible and returns some data
+SELECT COUNT(*) > 0 AS `mysql.user has data` FROM mysql.user;
+mysql.user has data
+1
+#
+# Upgrade from version 10.1
+#
+# Loading dump of 10.1 mysql schema
+# Running mysql_upgrade
+# Checking that mysql.user is accessible and returns some data
+SELECT COUNT(*) > 0 AS `mysql.user has data` FROM mysql.user;
+mysql.user has data
+1
+#
+# Upgrade from version 10.2
+#
+# Loading dump of 10.2 mysql schema
+# Running mysql_upgrade
+# Checking that mysql.user is accessible and returns some data
+SELECT COUNT(*) > 0 AS `mysql.user has data` FROM mysql.user;
+mysql.user has data
+1
+#
+# Upgrade from version 10.3
+#
+# Loading dump of 10.3 mysql schema
+# Running mysql_upgrade
+# Checking that mysql.user is accessible and returns some data
+SELECT COUNT(*) > 0 AS `mysql.user has data` FROM mysql.user;
+mysql.user has data
+1
+#
+# Upgrade from version 10.4
+#
+# Loading dump of 10.4 mysql schema
+# Running mysql_upgrade
+# Checking that mysql.user is accessible and returns some data
+SELECT COUNT(*) > 0 AS `mysql.user has data` FROM mysql.user;
+mysql.user has data
+1

mysql-test/main/mysql_upgrade.test

@@ -296,3 +296,32 @@ drop table mysql.global_priv;
 rename table mysql.global_priv_bak to mysql.global_priv;
 
 --echo # End of 10.4 tests
+
+#
+# MDEV-22249 Upgrade testing between major versions in MTR
+#
+--echo #
+--echo # Check that mysql_upgrade can be run on mysqldump
+--echo # of mysql schema from previous versions
+--echo #
+
+# The warning appears during mysql_upgrade, before the schema becomes consistent
+call mtr.add_suppression("innodb_table_stats has length mismatch in the column name table_name");
+
+--let $old_version= 5.5
+--source include/load_dump_and_upgrade.inc
+
+--let $old_version= 10.0
+--source include/load_dump_and_upgrade.inc
+
+--let $old_version= 10.1
+--source include/load_dump_and_upgrade.inc
+
+--let $old_version= 10.2
+--source include/load_dump_and_upgrade.inc
+
+--let $old_version= 10.3
+--source include/load_dump_and_upgrade.inc
+
+--let $old_version= 10.4
+--source include/load_dump_and_upgrade.inc