MTR's internal check of the test case 'percona_bug1289599' fails

[Yura Sorokin]

./mtr --debug-server percona_bug1289599

Although the test itself passes, it leaves some side effects in the mysql.user table.
The problem discovered during merging upstream 5.6.30 into Percona Server.

**********************************************************************
worker[1] Using MTR_BUILD_THREAD 300, with reserved ports 13000..13009
main.percona_bug1289599 [ pass ] 10

MTR's internal check of the test case 'main.percona_bug1289599' failed.
This means that the test case does not preserve the state that existed
before the test case was executed. Most likely the test case did not
do a proper clean-up. It could also be caused by the previous test run
by this thread, if the server wasn't restarted.
This is the diff of the states of the servers before and after the
test case was executed:
mysqltest: Logging to '/home/yura/ws/percona-build/mysql-test/var/tmp/check-mysqld_1.log'.
mysqltest: Results saved in '/home/yura/ws/percona-build/mysql-test/var/tmp/check-mysqld_1.result'.
mysqltest: Connecting to server localhost:13001 (socket /home/yura/ws/percona-build/mysql-test/var/tmp/mysqld.1.sock) as 'root', connection 'default', attempt 0 ...
mysqltest: ... Connected.
mysqltest: Start processing test commands from './include/check-testcase.test' ...
mysqltest: ... Done processing test commands.
--- /home/yura/ws/percona-build/mysql-test/var/tmp/check-mysqld_1.result 2016-05-13 14:49:24.864142374 +0300
+++ /home/yura/ws/percona-build/mysql-test/var/tmp/check-mysqld_1.reject 2016-05-13 14:49:25.099280056 +0300
@@ -928,6 +928,6 @@
 mysql.time_zone_name 2268956709
 mysql.time_zone_transition 3895294076
 mysql.time_zone_transition_type 168184411
-mysql.user 3907072784
+mysql.user 3891088588
 Warnings:
 Error 1146 Table 'mysql.host' doesn't exist

mysqltest: Result content mismatch

not ok
**********************************************************************

[Yura Sorokin (yura-sorokin)]

The problem seems to be with restoring original 'plugin' value in the 'mysql.user' table by executing
update mysql.user set plugin='';

This statement relies on the fact that at the beginning of the test the value of the 'plugin' field was also an empty string. This is not true, at least for 5.6.30, where this value is originally 'mysql_native_password'.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-2146