BUG#54903 BINLOG statement toggles session variables

When using BINLOG statement to execute rows log events, session variables
foreign_key_checks and unique_checks are changed temporarily.  As each rows
log event has their own special session environment and its own
foreign_key_checks and unique_checks can be different from current session
which executing the BINLOG statement. But these variables are not restored
correctly after BINLOG statement. This problem will cause that the following
statements fail or generate unexpected data.

In this patch, code is added to backup and restore these two variables.
So BINLOG statement will not affect current session's variables again.

mysql-test/extra/binlog_tests/binlog.test

@@ -302,5 +302,58 @@ BINLOG '
 SHOW BINLOG EVENTS;
 
 DROP TABLE t1;
+
+--echo
+--echo # BUG#54903 BINLOG statement toggles session variables
+--echo # ----------------------------------------------------------------------
+--echo # This test verify that BINLOG statement doesn't change current session's
+--echo # variables foreign_key_checks and unique_checks.
+--echo
+CREATE TABLE t1 (c1 INT KEY);
+
+SET @@SESSION.foreign_key_checks= ON;
+SET @@SESSION.unique_checks= ON;
+
+--echo # INSERT INTO t1 VALUES (1)
+--echo # foreign_key_checks=0 and unique_checks=0
+BINLOG '
+dfLtTBMBAAAAKQAAANcAAAAAABcAAAAAAAEABHRlc3QAAnQxAAEDAAE=
+dfLtTBcBAAAAIgAAAPkAAAAAABcAAAAAAAcAAf/+AQAAAA==
+';
+
+SELECT * FROM t1;
+--echo # Their values should be ON
+SHOW SESSION VARIABLES LIKE "%_checks";
+
+--echo
+SET @@SESSION.foreign_key_checks= OFF;
+SET @@SESSION.unique_checks= OFF;
+
+--echo # INSERT INTO t1 VALUES(2)
+--echo # foreign_key_checks=1 and unique_checks=1
+BINLOG '
+dfLtTBMBAAAAKQAAAKsBAAAAABcAAAAAAAEABHRlc3QAAnQxAAEDAAE=
+dfLtTBcBAAAAIgAAAM0BAAAAABcAAAAAAAEAAf/+AgAAAA==
+';
+
+SELECT * FROM t1;
+--echo # Their values should be OFF
+SHOW SESSION VARIABLES LIKE "%_checks";
+
+--echo # INSERT INTO t1 VALUES(2)
+--echo # foreign_key_checks=1 and unique_checks=1
+--echo # It should not change current session's variables, even error happens
+--error 1062
+BINLOG '
+dfLtTBMBAAAAKQAAAKsBAAAAABcAAAAAAAEABHRlc3QAAnQxAAEDAAE=
+dfLtTBcBAAAAIgAAAM0BAAAAABcAAAAAAAEAAf/+AgAAAA==
+';
+
+SELECT * FROM t1;
+--echo # Their values should be OFF
+SHOW SESSION VARIABLES LIKE "%_checks";
+
+DROP TABLE t1;
+
 disconnect fresh;
 

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

@@ -1330,3 +1330,62 @@ Log_name	Pos	Event_type	Server_id	End_log_pos	Info
 #	#	Write_rows	1	#	table_id: # flags: STMT_END_F
 #	#	Query	1	#	COMMIT
 DROP TABLE t1;
+
+# BUG#54903 BINLOG statement toggles session variables
+# ----------------------------------------------------------------------
+# This test verify that BINLOG statement doesn't change current session's
+# variables foreign_key_checks and unique_checks.
+
+CREATE TABLE t1 (c1 INT KEY);
+SET @@SESSION.foreign_key_checks= ON;
+SET @@SESSION.unique_checks= ON;
+# INSERT INTO t1 VALUES (1)
+# foreign_key_checks=0 and unique_checks=0
+BINLOG '
+dfLtTBMBAAAAKQAAANcAAAAAABcAAAAAAAEABHRlc3QAAnQxAAEDAAE=
+dfLtTBcBAAAAIgAAAPkAAAAAABcAAAAAAAcAAf/+AQAAAA==
+';
+SELECT * FROM t1;
+c1
+1
+# Their values should be ON
+SHOW SESSION VARIABLES LIKE "%_checks";
+Variable_name	Value
+foreign_key_checks	ON
+unique_checks	ON
+
+SET @@SESSION.foreign_key_checks= OFF;
+SET @@SESSION.unique_checks= OFF;
+# INSERT INTO t1 VALUES(2)
+# foreign_key_checks=1 and unique_checks=1
+BINLOG '
+dfLtTBMBAAAAKQAAAKsBAAAAABcAAAAAAAEABHRlc3QAAnQxAAEDAAE=
+dfLtTBcBAAAAIgAAAM0BAAAAABcAAAAAAAEAAf/+AgAAAA==
+';
+SELECT * FROM t1;
+c1
+1
+2
+# Their values should be OFF
+SHOW SESSION VARIABLES LIKE "%_checks";
+Variable_name	Value
+foreign_key_checks	OFF
+unique_checks	OFF
+# INSERT INTO t1 VALUES(2)
+# foreign_key_checks=1 and unique_checks=1
+# It should not change current session's variables, even error happens
+BINLOG '
+dfLtTBMBAAAAKQAAAKsBAAAAABcAAAAAAAEABHRlc3QAAnQxAAEDAAE=
+dfLtTBcBAAAAIgAAAM0BAAAAABcAAAAAAAEAAf/+AgAAAA==
+';
+ERROR 23000: Duplicate entry '2' for key 'PRIMARY'
+SELECT * FROM t1;
+c1
+1
+2
+# Their values should be OFF
+SHOW SESSION VARIABLES LIKE "%_checks";
+Variable_name	Value
+foreign_key_checks	OFF
+unique_checks	OFF
+DROP TABLE t1;

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

@@ -801,3 +801,62 @@ Log_name	Pos	Event_type	Server_id	End_log_pos	Info
 #	#	Write_rows	1	#	table_id: # flags: STMT_END_F
 #	#	Query	1	#	COMMIT
 DROP TABLE t1;
+
+# BUG#54903 BINLOG statement toggles session variables
+# ----------------------------------------------------------------------
+# This test verify that BINLOG statement doesn't change current session's
+# variables foreign_key_checks and unique_checks.
+
+CREATE TABLE t1 (c1 INT KEY);
+SET @@SESSION.foreign_key_checks= ON;
+SET @@SESSION.unique_checks= ON;
+# INSERT INTO t1 VALUES (1)
+# foreign_key_checks=0 and unique_checks=0
+BINLOG '
+dfLtTBMBAAAAKQAAANcAAAAAABcAAAAAAAEABHRlc3QAAnQxAAEDAAE=
+dfLtTBcBAAAAIgAAAPkAAAAAABcAAAAAAAcAAf/+AQAAAA==
+';
+SELECT * FROM t1;
+c1
+1
+# Their values should be ON
+SHOW SESSION VARIABLES LIKE "%_checks";
+Variable_name	Value
+foreign_key_checks	ON
+unique_checks	ON
+
+SET @@SESSION.foreign_key_checks= OFF;
+SET @@SESSION.unique_checks= OFF;
+# INSERT INTO t1 VALUES(2)
+# foreign_key_checks=1 and unique_checks=1
+BINLOG '
+dfLtTBMBAAAAKQAAAKsBAAAAABcAAAAAAAEABHRlc3QAAnQxAAEDAAE=
+dfLtTBcBAAAAIgAAAM0BAAAAABcAAAAAAAEAAf/+AgAAAA==
+';
+SELECT * FROM t1;
+c1
+1
+2
+# Their values should be OFF
+SHOW SESSION VARIABLES LIKE "%_checks";
+Variable_name	Value
+foreign_key_checks	OFF
+unique_checks	OFF
+# INSERT INTO t1 VALUES(2)
+# foreign_key_checks=1 and unique_checks=1
+# It should not change current session's variables, even error happens
+BINLOG '
+dfLtTBMBAAAAKQAAAKsBAAAAABcAAAAAAAEABHRlc3QAAnQxAAEDAAE=
+dfLtTBcBAAAAIgAAAM0BAAAAABcAAAAAAAEAAf/+AgAAAA==
+';
+ERROR 23000: Duplicate entry '2' for key 'PRIMARY'
+SELECT * FROM t1;
+c1
+1
+2
+# Their values should be OFF
+SHOW SESSION VARIABLES LIKE "%_checks";
+Variable_name	Value
+foreign_key_checks	OFF
+unique_checks	OFF
+DROP TABLE t1;

sql/sql_binlog.cc

@@ -50,6 +50,13 @@ void mysql_client_binlog_statement(THD* thd)
   }
   size_t decoded_len= base64_needed_decoded_length(coded_len);
 
+  /*
+    thd->options will be changed when applying the event. But we don't expect
+    it be changed permanently after BINLOG statement, so backup it first.
+    It will be restored at the end of this function.
+  */
+  ulonglong thd_options= thd->options;
+
   /*
     Allocation
   */
@@ -236,6 +243,7 @@ void mysql_client_binlog_statement(THD* thd)
   my_ok(thd);
 
 end:
+  thd->options= thd_options;
   rli->clear_tables_to_lock();
   my_free(buf, MYF(MY_ALLOW_ZERO_PTR));
   DBUG_VOID_RETURN;