- BUG#11986: Stored routines and triggers can fail if the code
has a non-ascii symbol
- BUG#16291: mysqldump corrupts string-constants with non-ascii-chars
- BUG#19443: INFORMATION_SCHEMA does not support charsets properly
- BUG#21249: Character set of SP-var can be ignored
- BUG#25212: Character set of string constant is ignored (stored routines)
- BUG#25221: Character set of string constant is ignored (triggers)
There were a few general problems that caused these bugs:
1. Character set information of the original (definition) query for views,
triggers, stored routines and events was lost.
2. mysqldump output query in client character set, which can be
inappropriate to encode definition-query.
3. INFORMATION_SCHEMA used strings with mixed encodings to display object
definition;
1. No query-definition-character set.
In order to compile query into execution code, some extra data (such as
environment variables or the database character set) is used. The problem
here was that this context was not preserved. So, on the next load it can
differ from the original one, thus the result will be different.
The context contains the following data:
- client character set;
- connection collation (character set and collation);
- collation of the owner database;
The fix is to store this context and use it each time we parse (compile)
and execute the object (stored routine, trigger, ...).
2. Wrong mysqldump-output.
The original query can contain several encodings (by means of character set
introducers). The problem here was that we tried to convert original query
to the mysqldump-client character set.
Moreover, we stored queries in different character sets for different
objects (views, for one, used UTF8, triggers used original character set).
The solution is
- to store definition queries in the original character set;
- to change SHOW CREATE statement to output definition query in the
binary character set (i.e. without any conversion);
- introduce SHOW CREATE TRIGGER statement;
- to dump special statements to switch the context to the original one
before dumping and restore it afterwards.
Note, in order to preserve the database collation at the creation time,
additional ALTER DATABASE might be used (to temporary switch the database
collation back to the original value). In this case, ALTER DATABASE
privilege will be required. This is a backward-incompatible change.
3. INFORMATION_SCHEMA showed non-UTF8 strings
The fix is to generate UTF8-query during the parsing, store it in the object
and show it in the INFORMATION_SCHEMA.
Basically, the idea is to create a copy of the original query convert it to
UTF8. Character set introducers are removed and all text literals are
converted to UTF8.
This UTF8 query is intended to provide user-readable output. It must not be
used to recreate the object. Specialized SHOW CREATE statements should be
used for this.
The reason for this limitation is the following: the original query can
contain symbols from several character sets (by means of character set
introducers).
Example:
- original query:
CREATE VIEW v1 AS SELECT _cp1251 'Hello' AS c1;
- UTF8 query (for INFORMATION_SCHEMA):
CREATE VIEW v1 AS SELECT 'Hello' AS c1;
- Use mysql_system_tables.sql to create MySQL system tables in
all places where we create them(mysql_install_db, mysql-test-run-pl
and mysql_fix_privilege_tables.sql)
context.
Routine arguments were evaluated in the security context of the routine
itself, not in the caller's context.
The bug is fixed the following way:
- Item_func_sp::find_and_check_access() has been split into two
functions: Item_func_sp::find_and_check_access() itself only
finds the function and check that the caller have EXECUTE privilege
on it. New function set_routine_security_ctx() changes security
context for SUID routines and checks that definer have EXECUTE
privilege too.
- new function sp_head::execute_trigger() is called from
Table_triggers_list::process_triggers() instead of
sp_head::execute_function(), and is effectively just as the
sp_head::execute_function() is, with all non-trigger related code
removed, and added trigger-specific security context switch.
- call to Item_func_sp::find_and_check_access() stays outside
of sp_head::execute_function(), and there is a code in
sql_parse.cc before the call to sp_head::execute_procedure() that
checks that the caller have EXECUTE privilege, but both
sp_head::execute_function() and sp_head::execute_procedure() call
set_routine_security_ctx() after evaluating their parameters,
and restore the context after the body is executed.
sp_grant_privileges(), the function that GRANTs EXECUTE + ALTER privs on a SP,
did so creating a user-entry with not password; mysql_routine_grant() would then
write that "change" to the user-table.
Basically, this fix contains a test case and removing of a workaround
for replication. This fix became possible after pushing WL#2897
(Complete definer support in stored routines).
The idea is to add DEFINER-clause in CREATE PROCEDURE and CREATE FUNCTION
statements. Almost all support of definer in stored routines had been already
done before this patch.
NOTE: this patch changes behaviour of dumping stored routines in mysqldump.
Before this patch, mysqldump did not dump DEFINER-clause for stored routines
and this was documented behaviour. In order to get full information about stored
routines, one should have dumped mysql.proc table. This patch changes this
behaviour, so that DEFINER-clause is dumped.
Since DEFINER-clause is not supported in CREATE PROCEDURE | FUNCTION statements
before this patch, the clause is covered by additional version-specific comments.
The problem was that databases with '_' in the name did not match a
correct ACL with a literal '_' (i.e. '\_') in the db name, only identical
strings matched. The fix makes this work, and also ACLs with wildcards in
the db name work.
Note: The following tests fails
- fulltext (Sergei has promised to fix)
- rpl_charset (Guilhem should fix)
- rpl_timezone (Dimitray has promised to fix)
Sanja needs to check out the calling of close_thread_tables() in sp_head.cc
Phase 2: Make SPs belong to a DB, and use qualified names.
As a side effect, using USE in an SP is no longer allowed.
(It just doesn't work otherwise.)
