Bug #53613: mysql_upgrade incorrectly revokes TRIGGER privilege on given table

Fixed an incomplete historical ALTER TABLE MODIFY trimming the trigger 
privilege bit from mysql.tables_priv.Table_priv column.
Removed the duplicate ALTER TABLE MODIFY.
Test suite added.

mysql-test/r/mysql_upgrade.result

@@ -169,3 +169,45 @@ DROP PROCEDURE testproc;
 WARNING: NULL values of the 'character_set_client' column ('mysql.proc' table) have been updated with a default value (latin1). Please verify if necessary.
 WARNING: NULL values of the 'collation_connection' column ('mysql.proc' table) have been updated with a default value (latin1_swedish_ci). Please verify if necessary.
 WARNING: NULL values of the 'db_collation' column ('mysql.proc' table) have been updated with default values. Please verify if necessary.
+#
+# Bug #53613: mysql_upgrade incorrectly revokes 
+#   TRIGGER privilege on given table
+#
+GRANT USAGE ON *.* TO 'user3'@'%';
+GRANT ALL PRIVILEGES ON `roelt`.`test2` TO 'user3'@'%';
+Run mysql_upgrade with all privileges on a user
+mtr.global_suppressions                            OK
+mtr.test_suppressions                              OK
+mysql.columns_priv                                 OK
+mysql.db                                           OK
+mysql.event                                        OK
+mysql.func                                         OK
+mysql.general_log
+Error    : You can't use locks with log tables.
+status   : OK
+mysql.help_category                                OK
+mysql.help_keyword                                 OK
+mysql.help_relation                                OK
+mysql.help_topic                                   OK
+mysql.host                                         OK
+mysql.ndb_binlog_index                             OK
+mysql.plugin                                       OK
+mysql.proc                                         OK
+mysql.procs_priv                                   OK
+mysql.servers                                      OK
+mysql.slow_log
+Error    : You can't use locks with log tables.
+status   : 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.user                                         OK
+SHOW GRANTS FOR 'user3'@'%';
+Grants for user3@%
+GRANT USAGE ON *.* TO 'user3'@'%'
+GRANT ALL PRIVILEGES ON `roelt`.`test2` TO 'user3'@'%'
+DROP USER 'user3'@'%';
+End of 5.1 tests

mysql-test/t/mysql_upgrade.test

@@ -108,3 +108,19 @@ CALL testproc();
 DROP PROCEDURE testproc;
 --cat_file $MYSQLTEST_VARDIR/tmp/41569.txt
 --remove_file $MYSQLTEST_VARDIR/tmp/41569.txt
+
+
+--echo #
+--echo # Bug #53613: mysql_upgrade incorrectly revokes 
+--echo #   TRIGGER privilege on given table
+--echo #
+
+GRANT USAGE ON *.* TO 'user3'@'%';
+GRANT ALL PRIVILEGES ON `roelt`.`test2` TO 'user3'@'%';
+--echo Run mysql_upgrade with all privileges on a user
+--exec $MYSQL_UPGRADE --skip-verbose --force 2>&1
+SHOW GRANTS FOR 'user3'@'%';
+
+DROP USER 'user3'@'%';
+
+--echo End of 5.1 tests

scripts/mysql_system_tables_fix.sql

@@ -58,7 +58,7 @@ ALTER TABLE tables_priv
     COLLATE utf8_general_ci DEFAULT '' NOT NULL,
   MODIFY Table_priv set('Select','Insert','Update','Delete','Create',
                         'Drop','Grant','References','Index','Alter',
-                        'Create View','Show view')
+                        'Create View','Show view','Trigger')
     COLLATE utf8_general_ci DEFAULT '' NOT NULL,
   COMMENT='Table privileges';
 
@@ -584,8 +584,6 @@ ALTER TABLE host MODIFY Trigger_priv enum('N','Y') COLLATE utf8_general_ci DEFAU
 ALTER TABLE db ADD Trigger_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL;
 ALTER TABLE db MODIFY Trigger_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL;
 
-ALTER TABLE tables_priv MODIFY Table_priv set('Select','Insert','Update','Delete','Create','Drop','Grant','References','Index','Alter','Create View','Show view','Trigger') COLLATE utf8_general_ci DEFAULT '' NOT NULL;
-
 UPDATE user SET Trigger_priv=Super_priv WHERE @hadTriggerPriv = 0;
 
 # Activate the new, possible modified privilege tables