database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-09-11 05:52:26 +03:00
Code Activity

The bug

Browse Source 
MDEV-4489 "Replication of big5, cp932, gbk, sjis strings makes wrong values on slave"
has been fixed.

Problem:
String constants of some Asian charsets (big5,cp932,gbk,sjis)
can have backslash '\' (0x5C) in the second byte of multi-byte characters.
Replicating of such constants using the standard '\'-escaping is dangerous.
Therefore, constants of these charsets are replicated using hex notation:
INSERT INTO t1 (a) VALUES (0x815C);

However, 0xHHHH constants do not work well in some cases,
because they can behave as strings and as numbers, depending on context
(for example, depending on the data type of the column in an INSERT statement).

This SQL script was not replicated correctly with statement-based replication:

SET NAMES gbk;
PREPARE STMT FROM 'INSERT INTO t1 (a) VALUES (?)';
SET @a = '1';
EXECUTE STMT USING @a;

The INSERT statement was replicated as:
INSERT INTO t1 (a) VALUES (0x31);

'1' was correctly converted to the number 1 on master.
But the 0x31 constant was treated as number 49 on slave.

Fix:

1. Binary log now uses X'HHHH' instead of 0xHHHH constants.
2. The X'HHHH' constants now work always as strings, in all contexts.
This is the SQL standard compliant behaviour.

After the fix, the above statement is replicated as:
INSERT INTO t1 (a) VALUES (X'31');
X'31' is treated as string '1' on slave, and is correctly converted to 1.


modified:
  @ mysql-test/r/ctype_cp932_binlog_stm.result
  @ mysql-test/r/select.result
  @ mysql-test/r/select_jcl6.result
  @ mysql-test/r/select_pkeycache.result
  @ mysql-test/r/user_var-binlog.result
  @ mysql-test/r/varbinary.result
  @ mysql-test/suite/binlog/r/binlog_stm_ctype_ucs.result
  @ mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result
  @ mysql-test/suite/rpl/r/rpl_charset_sjis.result
  @ mysql-test/suite/rpl/r/rpl_mdev382.result
  @ mysql-test/suite/rpl/t/rpl_charset_sjis.test
  @ mysql-test/t/ctype_cp932_binlog_stm.test
  @ mysql-test/t/select.test
  @ mysql-test/t/varbinary.test
    Adding and updating tests

  @ sql/item.cc
  @ sql/item.h
  @ sql/sql_yacc.yy
  @ sql/sql_lex.cc
    Splitting the implementations of X'HH' and 0xHH constants into two
    separate classes. Fixing the parser to distinguish the two syntaxes.

  @ sql/log_event.cc
    Using X'HH' instead of 0xHH for binary logging for string constants
    of the "dangerous" charsets.

  @ sql/sql_string.h
    Adding a helped method String::append_hex().
This commit is contained in:
Alexander Barkov
2013-05-08 13:36:17 +04:00
parent da846a153b
commit e013bf9f0e
20 changed files with 376 additions and 89 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
mysql-test/suite/rpl/t/rpl_charset_sjis.test
View File

@@ -23,4 +23,37 @@ sync_slave_with_master;
connection master;
# End of 5.0 tests
--echo #
--echo # Start of 5.5 tests
--echo #
--echo #
--echo # Bug#MDEV-4489 Replication of big5, cp932, gbk, sjis strings makes wrong values on slave
--echo #
connection master;
--echo --- on master ---
SET NAMES sjis;
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (0x31),(X'31'),('1');
PREPARE stmt FROM 'INSERT INTO t1 (a) VALUES (?)';
SET @a='1';
EXECUTE stmt USING @a;
DROP PREPARE stmt;
SELECT * FROM t1;
sync_slave_with_master;
connection slave;
--echo --- on slave ---
SELECT * FROM t1;
connection master;
--echo --- on master ---
DROP TABLE t1;
sync_slave_with_master;
connection master;
--echo #
--echo # End of 5.5 tests
--echo #
--source include/rpl_end.inc