BUG#47995: Mark system functions as unsafe

Problem: Some system functions that could return different values on
master and slave were not marked unsafe. In particular:
 GET_LOCK
 IS_FREE_LOCK
 IS_USED_LOCK
 MASTER_POS_WAIT
 RELEASE_LOCK
 SLEEP
 SYSDATE
 VERSION
Fix: Mark these functions unsafe.


mysql-test/extra/rpl_tests/rpl_stm_000001.test:
  - The test does not work in mixed mode any more, since it tries to
    simulate an error in the sql thread in a query that uses get_lock.
    Since get_lock now causes the query to be logged in row format,
    the error didn't happen. Hence, we now force statement mode.
  - Warnings must be disabled when the unsafe query is issued.
  - Replaced some save_master_pos+connection slave+sync_with_master
    by sync_slave_with_master.
mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result:
  updated result file
mysql-test/suite/binlog/r/binlog_stm_row.result:
  updated result file
mysql-test/suite/binlog/r/binlog_unsafe.result:
  updated result file
mysql-test/suite/binlog/t/binlog_killed.test:
  binlog_killed only works in statement format now, since
  it switches to row mode in mixed mode.
mysql-test/suite/binlog/t/binlog_stm_mix_innodb_myisam.test:
  suppress warnings for unsafe statements
mysql-test/suite/binlog/t/binlog_stm_row.test:
  - Suppress warnings in test that causes warnings.
  - The test sets binlog format explicitly, so no need to execute it
    twice.
mysql-test/suite/binlog/t/binlog_unsafe.test:
  Added test for all unsafe system functions. This test also includes
  system functions that were unsafe prior to BUG#47995.
mysql-test/suite/rpl/r/rpl_err_ignoredtable.result:
  updated result file
mysql-test/suite/rpl/r/rpl_get_lock.result:
  updated result file
mysql-test/suite/rpl/r/rpl_nondeterministic_functions.result:
  new result file
mysql-test/suite/rpl/r/rpl_stm_000001.result:
  updated result file
mysql-test/suite/rpl/r/rpl_trigger.result:
  updated result file
mysql-test/suite/rpl/t/rpl_err_ignoredtable.test:
  - suppress warnings for unsafe statement
  - replaced save_master_pos+connection slave+sync_with_master
    with sync_slave_with_master
mysql-test/suite/rpl/t/rpl_get_lock.test:
  update test case that causes new warnings
mysql-test/suite/rpl/t/rpl_nondeterministic_functions.test:
  Added new test case for nondeterministic functions.
mysql-test/suite/rpl/t/rpl_trigger.test:
  update test case that causes new warnings
sql/item_create.cc:
  Marked some system functions unsafe.
sql/item_strfunc.cc:
  Clarified comment related to this bug.
sql/sql_yacc.yy:
  Marked sysdate unsafe.

mysql-test/extra/rpl_tests/rpl_stm_000001.test

--- source include/have_binlog_format_mixed_or_statement.inc
+# Requires binlog_format=statement format since query involving
+# get_lock() is logged in row format if binlog_format=mixed or row.
+-- source include/have_binlog_format_statement.inc
 -- source include/master-slave.inc
 
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
+
+# Load some data into t1
 create table t1 (word char(20) not null);
 load data infile '../../std_data/words.dat' into table t1;
 --replace_result $MYSQL_TEST_DIR MYSQL_TEST_DIR
@@ -10,9 +15,7 @@ select * from t1 limit 10;
 #
 # Test slave with wrong password
 #
-save_master_pos;
-connection slave;
-sync_with_master;
+sync_slave_with_master;
 stop slave;
 connection master;
 set password for root@"localhost" = password('foo');
@@ -29,16 +32,12 @@ sleep 2;
 
 create table t3(n int);
 insert into t3 values(1),(2);
-save_master_pos;
-connection slave;
-sync_with_master;
+sync_slave_with_master;
 select * from t3;
 select sum(length(word)) from t1;
 connection master;
 drop table t1,t3;
-save_master_pos;
-connection slave;
-sync_with_master;
+sync_slave_with_master;
 
 # Test if the slave SQL thread can be more than 16K behind the slave
 # I/O thread (> IO_SIZE)
@@ -77,12 +76,13 @@ unlock tables;
 connection master;
 create table t2(id int);
 insert into t2 values(connection_id());
-save_master_pos;
 
 connection master1;
 # Avoid generating result
 create temporary table t3(n int);
+--disable_warnings
 insert into t3 select get_lock('crash_lock%20C', 1) from t2;
+--enable_warnings
 
 connection master;
 send update t1 set n = n + get_lock('crash_lock%20C', 2);
@@ -93,8 +93,11 @@ kill @id;
 # We don't drop t3 as this is a temporary table
 drop table t2;
 connection master;
+# The get_lock function causes warning for unsafe statement.
+--disable_warnings
 --error 1317,2013
 reap;
+--enable_warnings
 connection slave;
 # The SQL slave thread should now have stopped because the query was killed on
 # the master (so it has a non-zero error code in the binlog).
@@ -117,16 +120,12 @@ insert into mysql.user (Host, User, Password)
 select select_priv,user from mysql.user where user = _binary'blafasel2';
 update mysql.user set Select_priv = "Y" where User= _binary"blafasel2";
 select select_priv,user from mysql.user where user = _binary'blafasel2';
-save_master_pos;
-connection slave;
-sync_with_master;
+sync_slave_with_master;
 select n from t1;
 select select_priv,user from mysql.user where user = _binary'blafasel2';
 connection master1;
 drop table t1;
 delete from mysql.user where user="blafasel2";
-save_master_pos;
-connection slave;
-sync_with_master;
+sync_slave_with_master;
 
 # End of 4.1 tests

mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result

+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
 drop table if exists t1, t2;
 create table t1 (a int) engine=innodb;
 create table t2 (a int) engine=myisam;
@@ -224,6 +225,8 @@ create table t0 (n int);
 insert t0 select * from t1;
 set autocommit=1;
 insert into t0 select GET_LOCK("lock1",null);
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
 set autocommit=0;
 create table t2 (n int) engine=innodb;
 insert into t2 values (3);

mysql-test/suite/binlog/r/binlog_stm_row.result

+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
 DROP TABLE IF EXISTS t1;
 DROP TABLE IF EXISTS t2;
 set @saved_global_binlog_format = @@global.binlog_format;
@@ -29,6 +30,8 @@ SELECT RELEASE_LOCK('Bug#34306');
 RELEASE_LOCK('Bug#34306')
 1
 # con2
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
 SELECT RELEASE_LOCK('Bug#34306');
 RELEASE_LOCK('Bug#34306')
 1

mysql-test/suite/binlog/r/binlog_unsafe.result

@@ -327,4 +327,86 @@ Warnings:
 Note	1592	Statement may not be safe to log in statement format.
 DROP TABLE t1, t2;
 SET @@SESSION.SQL_MODE = @save_sql_mode;
+CREATE TABLE t1 (a VARCHAR(1000));
+INSERT INTO t1 VALUES (CURRENT_USER());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (FOUND_ROWS());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (GET_LOCK('tmp', 1));
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (IS_FREE_LOCK('tmp'));
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (IS_USED_LOCK('tmp'));
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (LOAD_FILE('../../std_data/words2.dat'));
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (MASTER_POS_WAIT('dummy arg', 4711, 1));
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (RELEASE_LOCK('tmp'));
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (ROW_COUNT());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (SESSION_USER());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (SLEEP(1));
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (SYSDATE());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (SYSTEM_USER());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (USER());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (UUID());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (UUID_SHORT());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+INSERT INTO t1 VALUES (VERSION());
+Warnings:
+Note	1592	Statement may not be safe to log in statement format.
+DELETE FROM t1;
+SET TIMESTAMP=1000000;
+INSERT INTO t1 VALUES
+(CURDATE()),
+(CURRENT_DATE()),
+(CURRENT_TIME()),
+(CURRENT_TIMESTAMP()),
+(CURTIME()),
+(LOCALTIME()),
+(LOCALTIMESTAMP()),
+(NOW()),
+(UNIX_TIMESTAMP()),
+(UTC_DATE()),
+(UTC_TIME()),
+(UTC_TIMESTAMP());
+SELECT * FROM t1;
+a
+1970-01-12
+1970-01-12
+16:46:40
+1970-01-12 16:46:40
+16:46:40
+1970-01-12 16:46:40
+1970-01-12 16:46:40
+1970-01-12 16:46:40
+1000000
+1970-01-12
+13:46:40
+1970-01-12 13:46:40
+DROP TABLE t1;
 "End of tests"

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

 -- source include/have_innodb.inc
--- source include/have_binlog_format_mixed_or_statement.inc
+-- source include/have_binlog_format_statement.inc
 
 # You cannot use `KILL' with the Embedded MySQL Server library,
 # because the embedded server merely runs inside the threads of the host

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

@@ -2,6 +2,9 @@
 # For both statement and row based bin logs 9/19/2005 [jbm]
 
 -- source include/have_binlog_format_statement.inc
+
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
+
 -- source extra/binlog_tests/mix_innodb_myisam_binlog.test
 
 set @@session.binlog_format=statement;

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

 --source include/have_log_bin.inc
---source include/have_binlog_format_row_or_statement.inc
+# Test sets its own binlog_format, so we restrict it to run only once
+--source include/have_binlog_format_row.inc
+
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
 
 # Get rid of previous tests binlog
 --disable_query_log

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

@@ -388,4 +388,56 @@ DELETE FROM t1 LIMIT 1;
 
 DROP TABLE t1, t2;
 SET @@SESSION.SQL_MODE = @save_sql_mode;
+
+#
+# BUG#47995: Mark user functions as unsafe
+#
+# Test that the system functions that are supposed to be marked unsafe
+# generate a warning.  Each INSERT statement below should generate a
+# warning.
+#
+
+CREATE TABLE t1 (a VARCHAR(1000));
+INSERT INTO t1 VALUES (CURRENT_USER());       #marked unsafe before BUG#47995
+INSERT INTO t1 VALUES (FOUND_ROWS());         #marked unsafe before BUG#47995
+INSERT INTO t1 VALUES (GET_LOCK('tmp', 1));
+INSERT INTO t1 VALUES (IS_FREE_LOCK('tmp'));
+INSERT INTO t1 VALUES (IS_USED_LOCK('tmp'));
+INSERT INTO t1 VALUES (LOAD_FILE('../../std_data/words2.dat')); #marked unsafe before BUG#47995
+INSERT INTO t1 VALUES (MASTER_POS_WAIT('dummy arg', 4711, 1));
+INSERT INTO t1 VALUES (RELEASE_LOCK('tmp'));
+INSERT INTO t1 VALUES (ROW_COUNT());          #marked unsafe before BUG#47995
+INSERT INTO t1 VALUES (SESSION_USER());       #marked unsafe before BUG#47995
+INSERT INTO t1 VALUES (SLEEP(1));
+INSERT INTO t1 VALUES (SYSDATE());
+INSERT INTO t1 VALUES (SYSTEM_USER());        #marked unsafe before BUG#47995
+INSERT INTO t1 VALUES (USER());               #marked unsafe before BUG#47995
+INSERT INTO t1 VALUES (UUID());               #marked unsafe before BUG#47995
+INSERT INTO t1 VALUES (UUID_SHORT());         #marked unsafe before BUG#47995
+INSERT INTO t1 VALUES (VERSION());
+DELETE FROM t1;
+
+# Since we replicate the TIMESTAMP variable, functions affected by the
+# TIMESTAMP variable are safe to replicate.  So we check that the
+# following following functions depend on the TIMESTAMP variable and
+# don't generate a warning.
+
+SET TIMESTAMP=1000000;
+INSERT INTO t1 VALUES
+  (CURDATE()),
+  (CURRENT_DATE()),
+  (CURRENT_TIME()),
+  (CURRENT_TIMESTAMP()),
+  (CURTIME()),
+  (LOCALTIME()),
+  (LOCALTIMESTAMP()),
+  (NOW()),
+  (UNIX_TIMESTAMP()),
+  (UTC_DATE()),
+  (UTC_TIME()),
+  (UTC_TIMESTAMP());
+SELECT * FROM t1;
+
+DROP TABLE t1;
+
 --echo "End of tests"

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

@@ -4,6 +4,7 @@ reset master;
 reset slave;
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
 start slave;
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
 create table t1 (a int primary key);
 create table t4 (a int primary key);
 insert into t1 values (1),(1);

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

@@ -4,6 +4,7 @@ reset master;
 reset slave;
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
 start slave;
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
 create table t1(n int);
 insert into t1 values(get_lock("lock",2));
 select get_lock("lock",2);

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

+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+CREATE TABLE t1 (a VARCHAR(1000));
+INSERT INTO t1 VALUES (CONNECTION_ID());
+INSERT INTO t1 VALUES (CONNECTION_ID());
+INSERT INTO t1 VALUES
+(CURDATE()),
+(CURRENT_DATE()),
+(CURRENT_TIME()),
+(CURRENT_TIMESTAMP()),
+(CURTIME()),
+(LOCALTIME()),
+(LOCALTIMESTAMP()),
+(NOW()),
+(UNIX_TIMESTAMP()),
+(UTC_DATE()),
+(UTC_TIME()),
+(UTC_TIMESTAMP());
+INSERT INTO t1 VALUES (RAND());
+INSERT INTO t1 VALUES (LAST_INSERT_ID());
+Comparing tables master:test.t1 and slave:test.t1
+DROP TABLE t1;

mysql-test/suite/rpl/r/rpl_stm_000001.result

@@ -4,6 +4,7 @@ reset master;
 reset slave;
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
 start slave;
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
 create table t1 (word char(20) not null);
 load data infile '../../std_data/words.dat' into table t1;
 load data local infile 'MYSQL_TEST_DIR/std_data/words.dat' into table t1;

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

@@ -4,6 +4,7 @@ reset master;
 reset slave;
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
 start slave;
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
 DROP TABLE IF EXISTS t1;
 DROP TABLE IF EXISTS t2;
 DROP TABLE IF EXISTS t3;

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

@@ -7,6 +7,8 @@
 
 -- source include/master-slave.inc
 
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
+
 connection master;
 create table t1 (a int primary key);
 create table t4 (a int primary key);
@@ -14,19 +16,15 @@ create table t4 (a int primary key);
 --error 1022, ER_DUP_ENTRY
 insert into t1 values (1),(1);
 insert into t4 values (1),(2);
-save_master_pos;
-connection slave;
 # as the t1 table is ignored on the slave, the slave should be able to sync
-sync_with_master;
+sync_slave_with_master;
 # check that the table has been ignored, because otherwise the test is nonsense
 show tables like 't1';
 show tables like 't4';
 SELECT * FROM test.t4 ORDER BY a;
 connection master;
 drop table t1;
-save_master_pos;
-connection slave;
-sync_with_master;
+sync_slave_with_master;
 
 # Now test that even critical errors (connection killed)
 # are ignored if rules allow it.
@@ -50,18 +48,17 @@ kill @id;
 drop table t2,t3;
 insert into t4 values (3),(4);
 connection master;
+# The get_lock function causes warning for unsafe statement.
+--disable_warnings
 --error 0,1317,2013
 reap;
+--enable_warnings
 connection master1;
-save_master_pos;
-connection slave;
-sync_with_master;
+sync_slave_with_master;
 SELECT * FROM test.t4 ORDER BY a;
 
 connection master1;
 DROP TABLE test.t4;
-save_master_pos;
-connection slave;
-sync_with_master;
+sync_slave_with_master;
 # End of 4.1 tests
 # Adding comment for force manual merge 5.0 -> wl1012. delete me if needed

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

 source include/master-slave.inc;
 
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
+
 create table t1(n int);
+# Use of get_lock gives a warning for unsafeness if binlog_format=statement
+--disable_warnings
 insert into t1 values(get_lock("lock",2));
+--enable_warnings
 dirty_close master;
 connection master1;
 select get_lock("lock",2);

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

+# ==== Purpose ====
+#
+# Test that nondeterministic system functions are correctly replicated.
+#
+# (Some functions are only correctly replicated if binlog_format=MIXED
+# or ROW.  See binlog_unsafe.test for a test that those variables are
+# indeed unsafe.)
+#
+# ==== Implementation ====
+#
+# We insert the values of each unsafe function into a table. Then we
+# replicate and check that the table is identical on slave.
+#
+# ==== Related bugs ====
+#
+# BUG#47995
+
+--source include/master-slave.inc
+
+CREATE TABLE t1 (a VARCHAR(1000));
+
+# We replicate the connection_id in the query_log_event
+INSERT INTO t1 VALUES (CONNECTION_ID());
+--connection master1
+INSERT INTO t1 VALUES (CONNECTION_ID());
+
+# We replicate the TIMESTAMP variable, so the following functions that
+# are affected by the TIMESTAMP variable should be safe to replicate.
+INSERT INTO t1 VALUES
+  (CURDATE()),
+  (CURRENT_DATE()),
+  (CURRENT_TIME()),
+  (CURRENT_TIMESTAMP()),
+  (CURTIME()),
+  (LOCALTIME()),
+  (LOCALTIMESTAMP()),
+  (NOW()),
+  (UNIX_TIMESTAMP()),
+  (UTC_DATE()),
+  (UTC_TIME()),
+  (UTC_TIMESTAMP());
+
+# We replicate the random seed in a rand_log_event
+INSERT INTO t1 VALUES (RAND());
+# We replicate the last_insert_id in an intvar_log_event
+INSERT INTO t1 VALUES (LAST_INSERT_ID());
+
+--sync_slave_with_master
+--let $diff_table_1= master:test.t1
+--let $diff_table_2= slave:test.t1
+--source include/diff_tables.inc
+
+DROP TABLE t1;

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

@@ -5,6 +5,8 @@
 --source include/have_binlog_format_mixed_or_statement.inc 
 --source include/master-slave.inc
 
+CALL mtr.add_suppression("Statement may not be safe to log in statement format.");
+
 --disable_warnings
 DROP TABLE IF EXISTS t1;
 DROP TABLE IF EXISTS t2;
@@ -89,7 +91,11 @@ end
 |
 
 delimiter ;|
+# The trigger causes a warning for unsafe statement when
+# binlog_format=statement since it uses get_lock.
+--disable_warnings
 insert into t1 set a = now();
+--enable_warnings
 select a=b && a=c from t1;
 let $time=`select a from t1`;
 
@@ -135,7 +141,11 @@ disconnect con2;
 truncate table t1;
 drop trigger t1_first;
 
+# The trigger causes a warning for unsafe statement when
+# binlog_format=statement since it uses get_lock.
+--disable_warnings
 insert into t1 values ("2003-03-03","2003-03-03","2003-03-03"),(bug12480(),bug12480(),bug12480()),(now(),now(),now());
+--enable_warnings
 select a=b && a=c from t1;
 
 drop function bug12480;

sql/item_create.cc

@@ -3524,6 +3524,7 @@ Create_func_get_lock Create_func_get_lock::s_singleton;
 Item*
 Create_func_get_lock::create(THD *thd, Item *arg1, Item *arg2)
 {
+  thd->lex->set_stmt_unsafe();
   thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
   return new (thd->mem_root) Item_func_get_lock(arg1, arg2);
 }
@@ -3635,6 +3636,7 @@ Create_func_is_free_lock Create_func_is_free_lock::s_singleton;
 Item*
 Create_func_is_free_lock::create(THD *thd, Item *arg1)
 {
+  thd->lex->set_stmt_unsafe();
   thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
   return new (thd->mem_root) Item_func_is_free_lock(arg1);
 }
@@ -3645,6 +3647,7 @@ Create_func_is_used_lock Create_func_is_used_lock::s_singleton;
 Item*
 Create_func_is_used_lock::create(THD *thd, Item *arg1)
 {
+  thd->lex->set_stmt_unsafe();
   thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
   return new (thd->mem_root) Item_func_is_used_lock(arg1);
 }
@@ -3961,6 +3964,8 @@ Create_func_master_pos_wait::create_native(THD *thd, LEX_STRING name,
   Item *func= NULL;
   int arg_count= 0;
 
+  thd->lex->set_stmt_unsafe();
+
   if (item_list != NULL)
     arg_count= item_list->elements;
 
@@ -4203,6 +4208,7 @@ Create_func_release_lock Create_func_release_lock::s_singleton;
 Item*
 Create_func_release_lock::create(THD *thd, Item *arg1)
 {
+  thd->lex->set_stmt_unsafe();
   thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
   return new (thd->mem_root) Item_func_release_lock(arg1);
 }
@@ -4325,6 +4331,7 @@ Create_func_sleep Create_func_sleep::s_singleton;
 Item*
 Create_func_sleep::create(THD *thd, Item *arg1)
 {
+  thd->lex->set_stmt_unsafe();
   thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
   return new (thd->mem_root) Item_func_sleep(arg1);
 }
@@ -4591,6 +4598,7 @@ Create_func_version Create_func_version::s_singleton;
 Item*
 Create_func_version::create(THD *thd)
 {
+  thd->lex->set_stmt_unsafe();
   return new (thd->mem_root) Item_static_string_func("version()",
                                                      server_version,
                                                      (uint) strlen(server_version),

sql/item_strfunc.cc

@@ -1827,8 +1827,9 @@ String *Item_func_database::val_str(String *str)
 
 
 /**
-  @todo
-  make USER() replicate properly (currently it is replicated to "")
+  @note USER() is replicated correctly if binlog_format=ROW or (as of
+  BUG#28086) binlog_format=MIXED, but is incorrectly replicated to ''
+  if binlog_format=STATEMENT.
 */
 bool Item_func_user::init(const char *user, const char *host)
 {

sql/sql_yacc.yy

@@ -7523,6 +7523,14 @@ function_call_nonkeyword:
           }
         | SYSDATE optional_braces
           {
+            /*
+              Unlike other time-related functions, SYSDATE() is
+              replication-unsafe because it is not affected by the
+              TIMESTAMP variable.  It is unsafe even if
+              sysdate_is_now=1, because the slave may have
+              sysdate_is_now=0.
+            */
+            Lex->set_stmt_unsafe();
             if (global_system_variables.sysdate_is_now == 0)
               $$= new (YYTHD->mem_root) Item_func_sysdate_local();
             else