The following statements support the CURRENT_USER() where a user is needed.

DROP USER 
RENAME USER CURRENT_USER() ...
GRANT ... TO CURRENT_USER()
REVOKE ... FROM CURRENT_USER()
ALTER DEFINER = CURRENT_USER() EVENTbut, When these statements are binlogged, CURRENT_USER() just is binlogged
as 'CURRENT_USER()', it is not expanded to the real user name. When slave 
executes the log event, 'CURRENT_USER()' is expand to the user of slave 
SQL thread, but SQL thread's user name always NULL. This breaks the replication.

After this patch, session's user will be written into query log events 
if these statements call CURREN_USER() or 'ALTER EVENT' does not assign a definer.


mysql-test/include/diff_tables.inc:
  Expend its abilities.
  Now it can diff not only in sessions of 'master' and 'slave', but 
  other sessions as well.
sql/log_event.cc:
  session's user will be written into Query_log_event, if is_current_user_used() is TRUE.
  On slave SQL thread, Only thd->invoker is written into Query_log_event,
  if it exists.
sql/sql_acl.cc:
  On slave SQL thread, grantor should copy from thd->invoker, if it exists
sql/sql_class.h:
  On slave SQL thread, thd->invoker is used to store the applying event's
  invoker.

1 files changed, 238 insertions, 0 deletions

diff --git a/mysql-test/suite/rpl/t/rpl_current_user.test b/mysql-test/suite/rpl/t/rpl_current_user.test
new file mode 100644
index 00000000000..72581ed7049
--- /dev/null
+++ b/mysql-test/suite/rpl/t/rpl_current_user.test
@@ -0,0 +1,238 @@
+##############################################################################
+# BUG#48321 CURRENT_USER() incorrectly replicated for DROP/RENAME USER,
+# REVOKE, GRANT, ALTER EVENT
+#
+# Calling CURRENT_USER() results into inconsistency between slave and master,
+# as the slave SQL thread has different user with common users.
+#
+# After the patch for bug#48321, session's user will be written into query log
+# event if CURRENT_USER() is called in 'DROP/RENAME USER', 'REVOKE', 'GRANT',
+# 'ALTER EVENT'.
+#
+##############################################################################
+source include/master-slave.inc;
+source include/have_binlog_format_statement.inc;
+
+--echo
+--echo # On slave2
+connect (slave2,127.0.0.1,root,,test,$SLAVE_MYPORT1,);
+connection slave2;
+
+--echo # Connect slave2 to slave
+--replace_result $SLAVE_MYPORT SLAVE_MYPORT;
+eval CHANGE MASTER TO MASTER_HOST='127.0.0.1', MASTER_PORT=$SLAVE_MYPORT,
+     MASTER_LOG_FILE='slave-bin.000001', MASTER_USER='root';
+START SLAVE;
+source include/wait_for_slave_to_start.inc;
+
+--echo
+--echo # [On master]
+connection master;
+--disable_warnings
+DROP VIEW IF EXISTS v_user;
+DROP VIEW IF EXISTS v_tables_priv;
+DROP VIEW IF EXISTS v_procs_priv;
+DROP PROCEDURE IF EXISTS p1;
+DROP PROCEDURE IF EXISTS my_grant;
+DROP PROCEDURE IF EXISTS my_revoke;
+DROP FUNCTION IF EXISTS my_user;
+DROP EVENT IF EXISTS e1;
+--enable_warnings
+CREATE TABLE t1(c1 char(100));
+CREATE VIEW test.v_user AS SELECT * FROM mysql.user WHERE User LIKE 'bug48321%';
+CREATE VIEW test.v_tables_priv AS SELECT * FROM mysql.tables_priv WHERE User LIKE 'bug48321%';
+CREATE VIEW test.v_procs_priv AS SELECT * FROM mysql.procs_priv WHERE User LIKE 'bug48321%';
+CREATE VIEW test.v_event AS SELECT definer FROM mysql.event WHERE name = 'e1';
+CREATE PROCEDURE p1() SELECT 1;
+--echo # bug48321_1-01234 has the max length(16) of user.
+GRANT ALL PRIVILEGES ON *.* TO 'bug48321_1-01234'@'localhost' WITH GRANT OPTION; 
+
+--echo
+--echo # Make sure the max lengths of user and host
+--echo # the user name is too lengh
+--error 1470
+GRANT CREATE USER ON *.* TO '01234567890123456'@'fakehost';
+--echo # the host name is too lengh
+--error 1470
+GRANT CREATE USER ON *.* TO 'fakename'@'0123456789012345678901234567890123456789012345678901234567890';
+
+--echo
+--echo # User 'bug48321_1-01234' connects to master by conn1
+connect (conn1, 127.0.0.1, 'bug48321_1-01234'@'localhost',,);
+connection conn1;
+--echo # [On conn1]
+--echo # Verify 'REVOKE ALL' statement
+REVOKE ALL PRIVILEGES, GRANT OPTION FROM CURRENT_USER();
+let $diff_table= test.v_user;
+let $diff_server_list= master, slave, slave2;
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'GRANT ... ON TABLE ...' statement
+connection conn1;
+GRANT CREATE, INSERT, SELECT ON TABLE test.t1 TO CURRENT_USER();
+let $diff_table= test.v_tables_priv;
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'GRANT ... ON PROCEDURE...' statement
+connection conn1;
+GRANT ALTER ROUTINE, EXECUTE ON PROCEDURE p1 TO CURRENT_USER();
+let $diff_table= test.v_procs_priv;
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'GRANT ... ON *.* ...' statement
+connection conn1;
+GRANT ALL PRIVILEGES ON *.* TO CURRENT_USER() WITH GRANT OPTION;
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'REVOKE ... ON TABLE ...' statement
+connection conn1;
+REVOKE CREATE, INSERT, SELECT ON TABLE t1 FROM CURRENT_USER();
+let $diff_table= test.v_tables_priv;
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'REVOKE ... ON PROCEDURE...' statement
+connection conn1;
+REVOKE ALTER ROUTINE, EXECUTE ON PROCEDURE p1 FROM CURRENT_USER();
+let $diff_table= test.v_procs_priv;
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'REVOKE ... ON *.* ...' statement
+connection conn1;
+REVOKE ALL PRIVILEGES ON *.* FROM CURRENT_USER();
+let $diff_table= test.v_user;
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'GRANT ...' statement in the procedure
+connection conn1;
+CREATE PROCEDURE my_grant()
+  GRANT CREATE, INSERT, SELECT ON TABLE test.t1 TO CURRENT_USER();
+call my_grant;
+let $diff_table= test.v_tables_priv;
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'REVOKE ... ON TABLE ...' statement in the procedure
+connection conn1;
+CREATE PROCEDURE my_revoke()
+  REVOKE CREATE, INSERT, SELECT ON TABLE t1 FROM CURRENT_USER();
+call my_revoke;
+let $diff_table= test.v_tables_priv;
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'RENAME USER ...' statement
+connection conn1;
+RENAME USER CURRENT_USER TO 'bug48321_2'@'localhost';
+let $diff_table= test.v_user;
+source include/rpl_diff_tables.inc;
+
+disconnect conn1;
+
+--echo 
+--echo # Verify 'DROP USER ...' statement
+connection master;
+GRANT CREATE USER ON *.* TO 'bug48321_2'@'localhost';
+connect (conn1, 127.0.0.1, 'bug48321_2'@'localhost',,);
+connection conn1;
+DROP USER CURRENT_USER();
+source include/rpl_diff_tables.inc;
+
+--echo 
+--echo # Verify 'ALTER EVENT...' statement
+connection master;
+CREATE EVENT e1 ON SCHEDULE EVERY 1 DAY DO SELECT * FROM t1;
+
+--echo # Explicitly assign CURRENT_USER() to definer
+ALTER DEFINER=CURRENT_USER() EVENT e1 ENABLE;
+let $diff_table= test.v_event;
+source include/rpl_diff_tables.inc;
+
+connection master;
+--echo
+--echo # Session user will be set as definer, if the statement does not assign
+--echo # a definer
+ALTER EVENT e1 ENABLE;
+sync_slave_with_master;
+source include/rpl_diff_tables.inc;
+
+--echo
+--echo # Verify that this patch does not affect the calling of CURRENT_USER() 
+--echo # in the other statements
+connection master;
+--echo # [On master]
+INSERT INTO t1 VALUES(CURRENT_USER()), ('1234');
+SELECT * FROM t1;
+sync_slave_with_master;
+--echo # [On slave]
+SELECT * FROM t1;
+--echo # [On slave2]
+sync_slave_with_master slave2;
+SELECT * FROM t1;
+
+connection master;
+--echo # [On master]
+UPDATE t1 SET c1=CURRENT_USER() WHERE c1='1234';
+SELECT * FROM t1;
+sync_slave_with_master;
+--echo # [On slave]
+SELECT * FROM t1;
+sync_slave_with_master slave2;
+--echo # [On slave2]
+SELECT * FROM t1;
+
+connection master;
+--echo # [On master]
+DELETE FROM t1 WHERE c1=CURRENT_USER();
+SELECT * FROM t1;
+sync_slave_with_master;
+--echo # [On slave]
+SELECT * FROM t1;
+sync_slave_with_master slave2;
+--echo # [On slave2]
+SELECT * FROM t1;
+
+connection master;
+--echo # [On master]
+CREATE TABLE t2(c1 char(100));
+
+DELIMITER |;
+CREATE FUNCTION my_user() RETURNS VARCHAR(64) 
+  SQL SECURITY INVOKER 
+BEGIN
+  INSERT INTO t2 VALUES(CURRENT_USER());
+  RETURN CURRENT_USER();
+END |
+DELIMITER ;|
+
+INSERT INTO t1 VALUES(my_user());
+SELECT * FROM t1;
+SELECT * FROM t2;
+sync_slave_with_master;
+--echo # [On slave]
+SELECT * FROM t1;
+SELECT * FROM t2;
+sync_slave_with_master slave2;
+--echo # [On slave2]
+SELECT * FROM t1;
+SELECT * FROM t2;
+
+--echo
+--echo # END
+connection master;
+DROP TABLE t1, t2;
+DROP VIEW v_user, v_tables_priv, v_procs_priv, v_event; 
+DROP PROCEDURE p1;
+DROP PROCEDURE my_grant;
+DROP PROCEDURE my_revoke;
+DROP FUNCTION my_user;
+DROP EVENT e1;
+sync_slave_with_master;
+sync_slave_with_master slave2;
+source include/master-slave-end.inc;