database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-08 11:22:35 +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

4
mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result
View File

@@ -946,10 +946,10 @@ show binlog events from <binlog_start>;
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Intvar # # INSERT_ID=10
master-bin.000001 # User var # # @`b`=_latin1 0x3135 COLLATE latin1_swedish_ci
master-bin.000001 # User var # # @`b`=_latin1 X'3135' COLLATE latin1_swedish_ci
master-bin.000001 # Begin_load_query # # ;file_id=#;block_len=#
master-bin.000001 # Intvar # # INSERT_ID=10
master-bin.000001 # User var # # @`b`=_latin1 0x3135 COLLATE latin1_swedish_ci
master-bin.000001 # User var # # @`b`=_latin1 X'3135' COLLATE latin1_swedish_ci
master-bin.000001 # Execute_load_query # # use `test`; LOAD DATA INFILE '../../std_data/rpl_loaddata.dat' INTO TABLE `t4` FIELDS TERMINATED BY '\t' ENCLOSED BY '' ESCAPED BY '\\' LINES TERMINATED BY '\n' (`a`, @`b`) SET `b`= @b + bug27417(2) ;file_id=#
master-bin.000001 # Query # # ROLLBACK
drop trigger trg_del_t2;