MDEV-13274 mysql_upgrade fails if dbname+tablename+partioname > 64 chars

InnoDB fix will come in MDEV-13360.
Here I just fix upgrades from old unfixed InnoDBs - bad data
makes the following copying ALTER TABLE to fail.

mysql-test/r/mysql_upgrade.result

@@ -464,4 +464,25 @@ even_longer_user_name_number_3_to_test_the_grantor_and_definer_field_length@loca
 even_longer_user_name_number_3_to_test_the_grantor_and_definer_field_length@localhost
 DROP USER very_long_user_name_number_1, very_long_user_name_number_2, even_longer_user_name_number_3_to_test_the_grantor_and_definer_field_length@localhost;
 DROP PROCEDURE test.pr;
-End of tests
+use test;
+alter table mysql.innodb_table_stats modify last_update int not null;
+create table extralongname_extralongname_extralongname_extralongname_ext (
+id int(10) unsigned not null,
+created_date date not null,
+created timestamp not null,
+primary key (created,id,created_date)
+) engine=innodb stats_persistent=1 default charset=latin1
+partition by range (year(created_date))
+subpartition by hash (month(created_date))
+subpartitions 2 (
+partition p2007 values less than (2008),
+partition p2008 values less than (2009)
+);
+select length(table_name) from mysql.innodb_table_stats;
+length(table_name)
+79
+79
+79
+79
+drop table extralongname_extralongname_extralongname_extralongname_ext;
+End of 10.0 tests

mysql-test/t/mysql_upgrade.test

 -- source include/mysql_upgrade_preparation.inc
 -- source include/have_working_dns.inc
 -- source include/have_innodb.inc
+-- source include/have_partition.inc
 
 #
 # Basic test that we can run mysql_upgrde and that it finds the
@@ -166,4 +167,26 @@ SELECT grantor FROM mysql.tables_priv WHERE db = 'mysql' AND table_name = 'user'
 DROP USER very_long_user_name_number_1, very_long_user_name_number_2, even_longer_user_name_number_3_to_test_the_grantor_and_definer_field_length@localhost;
 DROP PROCEDURE test.pr;
 
---echo End of tests
+#
+# MDEV-13274 mysql_upgrade fails if dbname+tablename+partioname > 64 chars
+#
+use test;
+alter table mysql.innodb_table_stats modify last_update int not null;
+
+create table extralongname_extralongname_extralongname_extralongname_ext (
+  id int(10) unsigned not null,
+  created_date date not null,
+  created timestamp not null,
+  primary key (created,id,created_date)
+) engine=innodb stats_persistent=1 default charset=latin1
+  partition by range (year(created_date))
+  subpartition by hash (month(created_date))
+  subpartitions 2 (
+    partition p2007 values less than (2008),
+    partition p2008 values less than (2009)
+  );
+--exec $MYSQL_UPGRADE --skip-verbose --force 2>&1
+select length(table_name) from mysql.innodb_table_stats;
+drop table extralongname_extralongname_extralongname_extralongname_ext;
+
+--echo End of 10.0 tests

scripts/mysql_system_tables_fix.sql

@@ -667,6 +667,15 @@ DROP PROCEDURE mysql.count_duplicate_host_names;
 # Convering the host name to lower case for existing users
 UPDATE user SET host=LOWER( host ) WHERE LOWER( host ) <> host;
 
+# fix bad data when upgrading from unfixed InnoDB (MDEV-13360)
+set @str="delete from innodb_index_stats where length(table_name) > 64";
+set @str=if(@have_innodb <> 0, @str, "set @dummy = 0");
+prepare stmt from @str;
+execute stmt;
+set @str=replace(@str, "innodb_index_stats", "innodb_table_stats");
+prepare stmt from @str;
+execute stmt;
+
 # update timestamp fields in the innodb stat tables
 set @str="alter table mysql.innodb_index_stats modify last_update timestamp not null default current_timestamp on update current_timestamp";
 set @str=if(@have_innodb <> 0, @str, "set @dummy = 0");