MDEV-35617: DROP USER should leave no active session for that user

DROP USER looks for sessions by the do-be-dropped user and if found:
* fails with ER_CANNOT_USER in Oracle mode
* continues with ER_ACTIVE_CONNECTIONS_FOR_USER_TO_DROP warning otherwise

Every user being dropped is marked with flag that disallow establishing
a new connections on behalf this user.

mysql-test/suite/binlog/t/binlog_grant.test

@@ -195,7 +195,9 @@ call mtr.add_suppression("Access denied; you need (at least one of) the BINLOG R
 --remove_file $MYSQLTEST_VARDIR/tmp/mysqlbinlog.sql
 --disconnect user1
 DROP TABLE t2,t1;
+--disable_warnings
 DROP USER user1@localhost;
+--enable_warnings
 
 --echo #
 --echo # End of 10.5 test

mysql-test/suite/binlog_encryption/rpl_ssl.result

@@ -46,6 +46,8 @@ Master_SSL_Key = 'MYSQL_TEST_DIR/std_data/client-key.pem'
 include/check_slave_is_running.inc
 connection master;
 drop user replssl@localhost;
+Warnings:
+Note	4227	Dropped users 'replssl'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 drop table t1;
 connection slave;
 include/stop_slave.inc

mysql-test/suite/engines/funcs/r/rpl_slave_status.result

@@ -30,6 +30,8 @@ n
 ==== Delete new replication user ====
 connection master;
 DROP USER rpl@127.0.0.1;
+Warnings:
+Note	4240	Dropped users 'rpl'@'127.0.0.1' have active connections. Use KILL CONNECTION if they should not be used anymore.
 FLUSH PRIVILEGES;
 connection slave;
 ==== Restart slave without privileges =====

mysql-test/suite/events/events_bugs.result

@@ -659,6 +659,8 @@ Expect 1
 1
 connection default;
 DROP USER evtest1@localhost;
+Warnings:
+Note	4227	Dropped users 'evtest1'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 Sleep 4 seconds
 SELECT COUNT(*) INTO @row_cnt FROM events_test.event_log;
 Sleep 4 seconds

mysql-test/suite/federated/federated_bug_25714.test

@@ -57,7 +57,9 @@ SELECT LAST_INSERT_ID();
 SELECT * from federated.t1;
 
 DROP TABLE federated.t1;
+--disable_warnings
 drop user fed@127.0.0.1;
+--enable_warnings
 SET @@GLOBAL.CONCURRENT_INSERT= @OLD_MASTER_CONCURRENT_INSERT;
 connection slave;
 DROP TABLE federated.t1;

mysql-test/suite/federated/federated_server.test

@@ -274,7 +274,9 @@ select * from federated.t1;
 
 # clean up test
 connection slave;
+disable_warnings;
 drop user test_fed@localhost;
+enable_warnings;
 drop database db_legitimate;
 drop database db_bogus;
 

mysql-test/suite/federated/update.test

@@ -25,7 +25,9 @@ drop table tt1;
 
 connection slave;
 drop database db1;
+disable_warnings;
 drop user my@localhost;
+enable_warnings;
 
 source include/federated_cleanup.inc;
 

mysql-test/suite/galera/r/MW-416.result

@@ -92,6 +92,8 @@ UNINSTALL PLUGIN plg;
 Got one of the listed errors
 connection node_1;
 DROP USER 'userMW416'@'localhost';
+Warnings:
+Note	4226	Dropped users 'userMW416'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 SHOW DATABASES;
 Database
 information_schema

mysql-test/suite/galera/r/galera_read_only.result

@@ -33,3 +33,5 @@ DROP TABLE t2;
 SET GLOBAL read_only=FALSE;
 DROP TABLE t1;
 DROP USER foo@localhost;
+Warnings:
+Note	4226	Dropped users 'foo'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.

mysql-test/suite/galera/r/galera_roles.result

@@ -167,6 +167,8 @@ disconnect foo_node_2;
 # Connect with node_1
 connection node_1;
 DROP USER foo@localhost;
+Warnings:
+Note	4226	Dropped users 'foo'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 DROP DATABASE test1;
 #
 # MDEV-10566: Create role statement replicated inconsistently in Galera Cluster

mysql-test/suite/galera/r/rename.result

@@ -44,5 +44,7 @@ i
 1
 connection node_1;
 DROP USER foo@localhost;
+Warnings:
+Note	4226	Dropped users 'foo'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 DROP TABLE t2;
 # End of tests

mysql-test/suite/plugins/t/multiauth.test

@@ -1,4 +1,5 @@
 --source include/not_ubsan.inc
+--source include/count_sessions.inc
 
 let $REGEX_VERSION_ID=/$mysql_get_server_version/VERSION_ID/;
 let $REGEX_PASSWORD_LAST_CHANGED=/password_last_changed": [0-9]*/password_last_changed": #/;
@@ -48,6 +49,7 @@ show create user mysqltest1;
 --echo # name does not match, password bad = failure
 --error 1
 --exec $try_auth -u mysqltest1 -pbad
+--source include/wait_until_count_sessions.inc
 --replace_result $dreplace "drop user 'USER'"
 eval $dreplace, mysqltest1;
 
@@ -68,6 +70,7 @@ show create user mysqltest1;
 --echo # name does not match, password bad = failure
 --error 1
 --exec $try_auth -u mysqltest1 -pbad
+--source include/wait_until_count_sessions.inc
 --replace_result $dreplace "drop user 'USER'"
 eval $dreplace, mysqltest1;
 
@@ -88,6 +91,7 @@ show create user mysqltest1;
 --echo # name does not match, password bad = failure
 --error 1
 --exec $try_auth -u mysqltest1 -pbad
+--source include/wait_until_count_sessions.inc
 --replace_result $dreplace "drop user 'USER'"
 eval $dreplace, mysqltest1;
 
@@ -108,6 +112,7 @@ show create user mysqltest1;
 --echo # name does not match, password bad = failure
 --error 1
 --exec $try_auth -u mysqltest1 -pbad
+--source include/wait_until_count_sessions.inc
 --replace_result $dreplace "drop user 'USER'"
 eval $dreplace, mysqltest1;
 
@@ -130,6 +135,7 @@ show create user mysqltest1;
 --echo # name does not match, password bad = failure
 --error 1
 --exec $try_auth -u mysqltest1 -pbad
+--source include/wait_until_count_sessions.inc
 --replace_result $dreplace "drop user 'USER'"
 eval $dreplace, mysqltest1;
 
@@ -146,6 +152,7 @@ show create user mysqltest1;
 --echo # password bad = failure
 --error 1
 --exec $try_auth -u mysqltest1 -pbad
+--source include/wait_until_count_sessions.inc
 drop user mysqltest1;
 
 #
@@ -198,6 +205,7 @@ show create user mysqltest1;
 --echo # SET PASSWORD helps
 set password for mysqltest1 = password('bla');
 --exec $try_auth -u mysqltest1 -pbla
+--source include/wait_until_count_sessions.inc
 --replace_result $dreplace "drop user 'USER'"
 eval $dreplace, mysqltest1;
 
@@ -219,6 +227,7 @@ show create user mysqltest1;
 --exec $try_auth -u mysqltest1 -pgood --plugin-dir=$plugindir/no
 --echo # no plugin, second password works = ok
 --exec $try_auth -u mysqltest1 -pworks --plugin-dir=$plugindir/no
+--source include/wait_until_count_sessions.inc
 drop user mysqltest1;
 
 uninstall soname 'auth_ed25519';

mysql-test/suite/plugins/t/pam.test

@@ -1,5 +1,6 @@
 let $PAM_PLUGIN_VERSION= $AUTH_PAM_SO;
 --source pam_init.inc
+--source include/count_sessions.inc
 
 --write_file $MYSQLTEST_VARDIR/tmp/pam_good.txt
 not very secret challenge
@@ -83,6 +84,7 @@ alter user test_pam password expire;
 --error 1
 --exec $MYSQL_TEST -u test_pam -pgoodpassword < $MYSQLTEST_VARDIR/tmp/pam_good2.txt
 
+--source include/wait_until_count_sessions.inc
 drop user test_pam;
 drop user pam_test;
 create user PAM_TEST identified via pam using 'mariadb_mtr';
@@ -104,6 +106,7 @@ set global pam_winbind_workaround=1;
 --remove_file $MYSQLTEST_VARDIR/tmp/pam_good2.txt
 --remove_file $MYSQLTEST_VARDIR/tmp/pam_bad.txt
 --remove_file $MYSQLTEST_VARDIR/tmp/pam_ugly.txt
+--source include/wait_until_count_sessions.inc
 drop user PAM_TEST;
 
 --echo #
@@ -121,6 +124,7 @@ show create user;
 EOF
 --exec $MYSQL_TEST -u pam_test < $MYSQLTEST_VARDIR/tmp/setpwd.txt
 --remove_file $MYSQLTEST_VARDIR/tmp/setpwd.txt
+--source include/wait_until_count_sessions.inc
 drop user pam_test;
 
 let $count_sessions= 1;

mysql-test/suite/plugins/t/parsec.test

@@ -1,5 +1,6 @@
 source include/platform.inc;
 source include/not_embedded.inc;
+source include/count_sessions.inc;
 
 if (`select count(*) = 0 from information_schema.plugins where plugin_name = 'parsec'`)
 {
@@ -41,6 +42,7 @@ if ($MTR_COMBINATION_WIN) {
 --echo # mysql -utest1 -ppwd --ssl-verify-server-cert -e "select test.have_ssl()"
 --exec $MYSQL --protocol tcp $host -utest1 -ppwd --ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
 
+source include/wait_until_count_sessions.inc;
 drop function have_ssl;
 drop user test1@'%';
 
@@ -57,4 +59,5 @@ disconnect con4;
 --error ER_ACCESS_DENIED_ERROR
 connect con5, localhost, test2, "wrong_pwd";
 connection default;
+source include/wait_until_count_sessions.inc;
 drop user test2@'%';

mysql-test/suite/roles/create_and_drop_current.result

@@ -10,6 +10,8 @@ ERROR 42000: You have an error in your SQL syntax; check the manual that corresp
 create role current_role;
 ERROR HY000: Operation CREATE ROLE failed for CURRENT_ROLE
 drop user current_user;
+Warnings:
+Note	4227	Dropped users 'foo'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 drop user current_role;
 ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'current_role' at line 1
 drop role current_user;

mysql-test/suite/roles/definer.result

@@ -620,6 +620,8 @@ drop view test.v1, test.v2, test.v3, test.v4, test.v5;
 drop table t1, t2;
 drop role role1, role2;
 drop user foo@localhost;
+Warnings:
+Note	4227	Dropped users 'foo'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 drop database mysqltest1;
 use test;
 create user utest;

mysql-test/suite/roles/definer.test

@@ -327,7 +327,9 @@ drop view test.v1, test.v2, test.v3, test.v4, test.v5;
 drop table t1, t2;
 drop role role1, role2;
 drop user foo@localhost;
+--disable_warnings
 drop database mysqltest1;
+--enable_warnings
 use test;
 
 ##################################################

mysql-test/suite/roles/drop_current_user-5176.result

@@ -2,6 +2,8 @@ create user foo@localhost;
 grant create user on *.* to foo@localhost;
 connect  foo,localhost,foo,,;
 drop user foo@localhost;
+Warnings:
+Note	4227	Dropped users 'foo'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 select * from information_schema.applicable_roles;
 GRANTEE	ROLE_NAME	IS_GRANTABLE	IS_DEFAULT
 show grants;

mysql-test/suite/rpl/r/rpl_password_boundaries.result

@@ -54,6 +54,8 @@ ERROR HY000: String 'воттакойужпарольвоттакойужпар
 connection master;
 set sql_log_bin=0;
 drop user rpl32@127.0.0.1, rpl33@127.0.0.1, rpl16cyr@127.0.0.1, rpl17mix@127.0.0.1;
+Warnings:
+Note	4227	Dropped users 'rpl16cyr'@'127.0.0.1' have active connections. Use KILL CONNECTION if they should not be used anymore.
 set sql_log_bin=1;
 connection slave;
 change master to master_user='root',master_password='';

mysql-test/suite/rpl/r/rpl_perfschema_connect_config.result

@@ -57,6 +57,8 @@ include/assert.inc [Value returned by SSS and PS table for SSL_Key should be sam
 include/assert.inc [Value returned by SSS and PS table for SSL_Verify_Server_Certificate should be same.]
 connection master;
 drop user replssl@localhost;
+Warnings:
+Note	4227	Dropped users 'replssl'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 connection slave;
 include/stop_slave.inc
 CHANGE MASTER TO

mysql-test/suite/rpl/r/rpl_slave_alias_replica.result

@@ -22,6 +22,8 @@ connection slave;
 connection master;
 "Command: SHOW SLAVE HOSTS --> SHOW REPLICA HOSTS"
 DROP USER 'repl_user';
+Warnings:
+Note	4227	Dropped users 'repl_user'@'%' have active connections. Use KILL CONNECTION if they should not be used anymore.
 connection slave;
 "Command: SHOW SLAVE IO/SQL THREAD --> SHOW REPLICA IO/SQL THREAD"
 STOP REPLICA IO_THREAD;

mysql-test/suite/rpl/r/rpl_slave_restart_long_password.result

@@ -18,6 +18,8 @@ include/check_slave_param.inc [Slave_IO_Running]
 connection master;
 SET SQL_LOG_BIN=0;
 DROP USER rpl@127.0.0.1;
+Warnings:
+Note	4227	Dropped users 'rpl'@'127.0.0.1' have active connections. Use KILL CONNECTION if they should not be used anymore.
 FLUSH PRIVILEGES;
 SET SQL_LOG_BIN=1;
 connection slave;

mysql-test/suite/rpl/r/rpl_slave_status.result

@@ -30,6 +30,8 @@ n
 ==== Delete new replication user ====
 connection master;
 DROP USER rpl@127.0.0.1;
+Warnings:
+Note	4227	Dropped users 'rpl'@'127.0.0.1' have active connections. Use KILL CONNECTION if they should not be used anymore.
 FLUSH PRIVILEGES;
 connection slave;
 ==== Restart slave without privileges =====

mysql-test/suite/rpl/r/rpl_ssl.result

@@ -46,6 +46,8 @@ Master_SSL_Key = 'MYSQL_TEST_DIR/std_data/client-key.pem'
 include/check_slave_is_running.inc
 connection master;
 drop user replssl@localhost;
+Warnings:
+Note	4227	Dropped users 'replssl'@'localhost' have active connections. Use KILL CONNECTION if they should not be used anymore.
 drop table t1;
 connection slave;
 include/stop_slave.inc
@@ -55,5 +57,5 @@ master_ssl = 1,
 master_ssl_ca = '',
 master_ssl_cert = '',
 master_ssl_key = '';
-End of 5.0 tests
+# End of 5.0 tests
 include/rpl_end.inc

mysql-test/suite/rpl/r/rpl_ssl1.result

@@ -112,6 +112,8 @@ master_ssl_verify_server_cert=0,
 master_ssl=1;
 connection master;
 drop user replssl@127.0.0.1;
+Warnings:
+Note	4227	Dropped users 'replssl'@'127.0.0.1' have active connections. Use KILL CONNECTION if they should not be used anymore.
 connection slave;
 drop user replssl@127.0.0.1;
 include/rpl_end.inc

mysql-test/suite/rpl/t/rpl_ssl1.test

@@ -61,7 +61,9 @@ change master to master_user='root',master_password='', master_ssl=0;
 start slave;
 --source include/wait_for_slave_to_start.inc
 connection master;
+disable_warnings;
 drop user replssl@localhost;
+enable_warnings;
 drop table t1;
 
 sync_slave_with_master;