Bug #77436 procs_priv table not restored with sql_mode traditional and only_full_group_by

Description:
MySQL procs_priv table is not correctly restored or its content shown and thus user privileges are missing after restore.

How to repeat:
Reproducible test case:

* fresh MySQL intallation
mysql_install_db --datadir=/home/mysql/data/mysqld1 --user=mysql --basedir=/home/mysql/product/mysql-5.6.23

* sql_mode = TRADITIONAL,ONLY_FULL_GROUP_BY

* start

mysql> show global variables like 'sql_mode';

sql_mode = ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,TRADITIONAL,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

create user exec@localhost identified by 'exec';

delimiter //
CREATE PROCEDURE test.dorepeat(p1 INT)
BEGIN
SET @x = 0;
REPEAT SET @x = @x + 1; UNTIL @x > p1 END REPEAT;
END;
//
delimiter ;

grant execute on procedure test.dorepeat to exec@'localhost'; 

select * from mysql.procs_priv;
+-----------+------+------+--------------+--------------+----------------+-----------+---------------------+
| Host      | Db   | User | Routine_name | Routine_type | Grantor        | Proc_priv | Timestamp           |
+-----------+------+------+--------------+--------------+----------------+-----------+---------------------+
| localhost | test | exec | dorepeat     | PROCEDURE    | root@localhost | Execute   | 0000-00-00 00:00:00 |
+-----------+------+------+--------------+--------------+----------------+-----------+---------------------+

--> Timestamp IMHO is wrong. Should be actual Timestamp!

CREATE TABLE `procs_priv` (
  `Host` char(60) COLLATE utf8_bin NOT NULL DEFAULT '',
  `Db` char(64) COLLATE utf8_bin NOT NULL DEFAULT '',
  `User` char(16) COLLATE utf8_bin NOT NULL DEFAULT '',
  `Routine_name` char(64) CHARACTER SET utf8 NOT NULL DEFAULT '',
  `Routine_type` enum('FUNCTION','PROCEDURE') COLLATE utf8_bin NOT NULL,
  `Grantor` char(77) COLLATE utf8_bin NOT NULL DEFAULT '',
  `Proc_priv` set('Execute','Alter Routine','Grant') CHARACTER SET utf8 NOT NULL DEFAULT '',
  `Timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`Host`,`Db`,`User`,`Routine_name`,`Routine_type`),
  KEY `Grantor` (`Grantor`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='Procedure privileges'

* Then do dump:

mysqldump \
  --user=root \
  --all-databases \
  --flush-privileges \
  --single-transaction \
  --master-data=2 \
  --flush-logs \
  --triggers \
  --routines \
  --events \
  --hex-blob > /tmp/full_backup.sql

* Fresh installation:

mysql_install_db --datadir=/home/mysql/data/mysqld1 --user=mysql --basedir=/home/mysql/product/mysql-5.6.23

select * from mysql.procs_priv;
Empty set

-rw-rw---- 1 mysql mysql   8875 Jun 22 16:43 procs_priv.frm
-rw-rw---- 1 mysql mysql      0 Jun 22 16:43 procs_priv.MYD
-rw-rw---- 1 mysql mysql   4096 Jun 22 16:43 procs_priv.MYI

* Do restore

mysql -u root mysql < /tmp/full_backup.sql 
echo $?
0

select * from mysql.procs_priv;
Empty set

-rw-rw---- 1 mysql mysql   8875 Jun 22 16:39 procs_priv.frm
-rw-rw---- 1 mysql mysql    850 Jun 22 16:39 procs_priv.MYD
-rw-rw---- 1 mysql mysql   8192 Jun 22 16:40 procs_priv.MYI

Data are there but not visible...

Suggested fix:
1. Procs_priv table should reflect timestamp correctly.
2. restore should complain an fail
3. privileges should be visible at all.

Hello Oli Sennhauser,

Thank you for the report and repeatable steps.
Observed this with 5.6.26.

Thanks,
Umesh