Analysis:
========================
sql_mode "NO_BACKSLASH_ESCAPES": When user want to use backslash as character input,
instead of escape character in a string literal then sql_mode can be set to
"NO_BACKSLASH_ESCAPES". With this mode enabled, backslash becomes an ordinary
character like any other.
SQL_MODE set applies to the current client session. And while creating the stored
procedure, MySQL stores the current sql_mode and always executes the stored
procedure in sql_mode stored with the Procedure, regardless of the server SQL
mode in effect when the routine is invoked.
In the scenario (for which bug is reported), the routine is created with
sql_mode=NO_BACKSLASH_ESCAPES. And routine is executed with the invoker sql_mode
is "" (NOT SET) by executing statement "call testp('Axel\'s')".
Since invoker sql_mode is "" (NOT_SET), the '\' in 'Axel\'s'(argument to function)
is considered as escape character and column "a" (of table "t1") values are
updated with "Axel's". The binary log generated for above update operation is as below,
set sql_mode=XXXXXX (for no_backslash_escapes)
update test.t1 set a= NAME_CONST('var',_latin1'Axel\'s' COLLATE 'latin1_swedish_ci');
While logging stored procedure statements, the local variables (params) used in
statements are replaced with the NAME_CONST(var_name, var_value) (Internal function)
(http://dev.mysql.com/doc/refman/5.6/en/miscellaneous-functions.html#function_name-const)
On slave, these logs are applied. NAME_CONST is parsed to get the variable and its
value. Since, stored procedure is created with sql_mode="NO_BACKSLASH_ESCAPES", the sql_mode
is also logged in. So that at slave this sql_mode is set before executing the statements
of routine. So at slave, sql_mode is set to "NO_BACKSLASH_ESCAPES" and then while
parsing NAME_CONST of string variable, '\' is considered as NON ESCAPE character
and parsing reported error for "'" (as we have only one "'" no backslash).
At slave, parsing was proper with sql_mode "NO_BACKSLASH_ESCAPES".
But above error reported while writing bin log, "'" (of Axel's) is escaped with
"\" character. Actually, all special characters (n, r, ', ", \, 0...) are escaped
while writing NAME_CONST for string variable(param, local variable) in bin log
Airrespective of "NO_BACKSLASH_ESCAPES" sql_mode. So, basically, the problem is
that logging string parameter does not take into account sql_mode value.
Fix:
========================
So when sql_mode is set to "NO_BACKSLASH_ESCAPES", escaping characters as
(n, r, ', ", \, 0...) should be avoided. To do so, added a check to not to
escape such characters while writing NAME_CONST for string variables in bin
log.
And when sql_mode is set to NO_BACKSLASH_ESCAPES, quote character "'" is
represented as ''.
http://dev.mysql.com/doc/refman/5.6/en/string-literals.html (There are several
ways to include quote characters within a string: )
InnoDB specified.
NO_ENGINE_SUBSTITUTION added to TRADITIONAL sql mode to prevent
silent conversions from InnoDB to MyISAM in that sql mode.
A number of test case results files updated to reflect this change.
Test added to sql_mode.test that checks that TRADITIONAL really
includes NO_ENGINE_SUBSTITUION.
The SQL-mode PAD_CHAR_TO_FULL_LENGTH could prevent a DROP USER
statement from privileges associated with the user being dropped.
What ocurred was that reading from the User and Host fields of
the tables tables_priv or columns_priv would yield values padded
with spaces, causing a failure to match a specified user or host
('user' != 'user ');
The solution is to disregard the PAD_CHAR_TO_FULL_LENGTH mode
when iterating over and matching values in the privileges tables
for a DROP USER statement.
SQL-mode PAD_CHAR_TO_FULL_LENGTH affected mysqld's user-table too. If
enabled, user-name and host were space-padded and no longer matched
the login-data of incoming connexions.
Patch disregards pad-flag while loading privileges so ability to log
in does not depend on SQL-mode.
This pads the value of CHAR columns with spaces up to full column length (according to ANSI)
It's not makde part of oracle or ansi mode yet, as this would cause a notable behaviour change.
Added uuid_short(), a generator for increasing 'unique' longlong integers (8 bytes)
symptom). sys_var::check_set() was wrong. mysqlbinlog makes use of such SET SQL_MODE=N
(where N is interpreted like if SQL_MODE was a field of type SET), so
this bug affected recovery from binlogs if the server was running with certain SQL_MODE values,
for example the default values on Windows (STRICT_TRANS_TABLES); to work around this bug people
had to edit mysqlbinlog's output.
"CHARACTER SET", "COLLATE", and "DEFAULT" are always
printed(excepting MODE_MYSQL323 and MODE_MYSQL40)
"AUTO_INCREMENT", "ON UPDATE CURRENT_TIMESTAMP" are printed only
if NO_FIELD_OPTIONS is not set.
"SHOW CREATE TABLE" mysql-4.0 and mysql-3.23
compatibiliry mode change:
Check that a binary collation adds 'binary'
suffix into a char() column definition in
mysql40 and mysql2323 modes. This allows
not to lose the column's case sensitivity
when loading the dump in pre-4.1 servers.
Added a check to recover from IGNORE_SPACE in this situation:
<ident-character(s)><space><dot><ident-character(s)>
The ignored space led to the false identification of the dot
as an ident separator (like "db.table").
bmove_allign -> bmove_align
Added OLAP function ROLLUP
Split mysql_fix_privilege_tables to a script and a .sql data file
Added new (MEMROOT*) functions to avoid calling current_thd() when creating some common objects.
Added table_alias_charset, for easier --lower-case-table-name handling
Better SQL_MODE handling (Setting complex options also sets sub options)
New (faster) assembler string functions for x86
