The CONVERT_TZ function crashes the server when the
timezone argument is an empty SET field value.
1) The CONVERT_TZ may find a timezone string in the
tz_names hash.
2) A string representation of the empty SET is a
String of zero length with the NULL pointer.
3) If the key argument length is zero, hash functions
do comparison using the length of the record being
compared against.
I.e. a zero-length String buffer is an invalid
argument for hash search functions, and if String
points to NULL buffer, hashcmp() fails with SEGV
accessing that memory.
The my_tz_find function has been modified to
treat empty Strings as invalid timezone values
to skip unnecessary hash search.
Problem 1: tests often fail in pushbuild with a timeout when waiting
for the slave to start/stop/receive error.
Fix 1: Updated the wait_for_slave_* macros in the following way:
- The timeout is increased by a factor ten
- Refactored the macros so that wait_for_slave_param does the work for
the other macros.
Problem 2: Tests are often incorrectly written, lacking a
source include/wait_for_slave_to_[start|stop].inc.
Fix 2: Improved the chance to get it right by adding
include/start_slave.inc and include/stop_slave.inc, and updated tests
to use these.
Problem 3: The the built-in test language command
wait_for_slave_to_stop is a misnomer (does not wait for the slave io
thread) and does not give as much debug info in case of failure as
the otherwise equivalent macro
source include/wait_for_slave_sql_to_stop.inc
Fix 3: Replaced all calls to the built-in command by a call to the
macro.
Problem 4: Some, but not all, of the wait_for_slave_* macros had an
implicit connection slave. This made some tests confusing to read,
and made it more difficult to use the macro in circular replication
scenarios, where the connection named master needs to wait.
Fix 4: Removed the implicit connection slave from all
wait_for_slave_* macros, and updated tests to use an explicit
connection slave where necessary.
Problem 5: The macros wait_slave_status.inc and wait_show_pattern.inc
were unused. Moreover, using them is difficult and error-prone.
Fix 5: remove these macros.
Problem 6: log_bin_trust_function_creators_basic failed when running
tests because it assumed @@global.log_bin_trust_function_creators=1,
and some tests modified this variable without resetting it to its
original value.
Fix 6: All tests that use this variable have been updated so that
they reset the value at end of test.
The problem was that some facilities (like CONVERT_TZ() function or
server HELP statement) may require implicit access to some tables in
'mysql' database. This access was done by ordinary means of adding
such tables to the list of tables the query is going to open.
However, if we issued LOCK TABLES before that, we would get "table
was not locked" error trying to open such implicit tables.
The solution is to treat certain tables as MySQL system tables, like
we already do for mysql.proc. Such tables may be opened for reading
at any moment regardless of any locks in effect. The cost of this is
that system table may be locked for writing only together with other
system tables, it is disallowed to lock system tables for writing and
have any other lock on any other table.
After this patch the following tables are treated as MySQL system
tables:
mysql.help_category
mysql.help_keyword
mysql.help_relation
mysql.help_topic
mysql.proc (it already was)
mysql.time_zone
mysql.time_zone_leap_second
mysql.time_zone_name
mysql.time_zone_transition
mysql.time_zone_transition_type
These tables are now opened with open_system_tables_for_read() and
closed with close_system_tables(), or one table may be opened with
open_system_table_for_update() and closed with close_thread_tables()
(the latter is used for mysql.proc table, which is updated as part of
normal MySQL server operation). These functions may be used when
some tables were opened and locked already.
NOTE: online update of time zone tables is not possible during
replication, because there's no time zone cache flush neither on LOCK
TABLES, nor on FLUSH TABLES, so the master may serve stale time zone
data from cache, while on slave updated data will be loaded from the
time zone tables.
(4.1 version, with post-review fixes)
The fix for another Bug (6439) limited FROM_UNIXTIME() to
TIMESTAMP_MAX_VALUE which is 2145916799 or 2037-12-01 23:59:59 GMT,
however unix timestamp in general is not considered to be limited
by this value. All dates up to power(2,31)-1 are valid.
This patch extends allowed TIMESTAMP range so, that max
TIMESTAMP value is power(2,31)-1. It also corrects
FROM_UNIXTIME() and UNIX_TIMESTAMP() functions, so that
max allowed UNIX_TIMESTAMP() is power(2,31)-1. FROM_UNIXTIME()
is fixed accordingly to allow conversion of dates up to
2038-01-19 03:14:07 UTC. The patch also fixes CONVERT_TZ()
function to allow extended range of dates.
The main problem solved in the patch is possible overflows
of variables, used in broken-time representation to time_t
conversion (required for UNIX_TIMESTAMP).
Under row-based replication, DELETE FROM will now always be
replicated as individual row deletions, while TRUNCATE TABLE will
always be replicated as a statement.
trigger fails".
In cases when CONVERT_TZ() function was used in trigger or stored function
(or in stored procedure which was called from trigger or stored function)
error about non existing '.' table was reported.
Statements that use CONVERT_TZ() function should have time zone related
tables in their table list. tz_init_table_list() function which is used
to produce part of table list containing those tables didn't set
TABLE_LIST::db_length/table_name_length members properly. As result time
zone tables needed for CONVERT_TZ() function were incorrectly handled by
prelocking algorithm and "Table '.' doesn't exist' error was emitted.
This fix changes tz_init_table_list() in such way that it properly inits
TABLE_LIST::table_name_length/db_length members and thus produces table list
which can be handled by prelocking algorithm correctly.
does not work well together". Now using simplier and more correct
implementation of st_lex::unlink_first_table()/link_first_table_back()
(It also nicely handles case when global table list is created because
of implictly used time zone tables). (2nd attempt)
Fix for bug #7705 "CONVERT_TZ() crashes with subquery/WHERE on index
column". Implemented new approach for caching objects for constant
time zone arguments. Now instead of determining whenever these arguments
are constants and performing time zone lookup at fix_fields() stage, we
do it on first get_date() invocation.
Cleanup of global @@time_zone variable handling.
tables requires privileges for them if some table or column level grants
present" (with after-review fixes).
We should set SELECT_ACL for implicitly opened tables in
my_tz_check_n_skip_implicit_tables() to be able to bypass privilege
checking in check_grant(). Also we should exclude those tables from
privilege checking in multi-update.
Under strict mode MySQL will generate an error message if there was any conversion when assigning data to a field.
Added checking of date/datetime fields.
If strict mode, give error if we have not given value to field without a default value (for INSERT)
Instead of trying to open time zone tables during calculation of CONVERT_TZ() function
or setting of @@time_zone variable we should open and lock them with the rest of
statement's table (so we should add them to global table list) and after that use such
pre-opened tables for loading info about time zones.
Added basic per-thread time zone functionality (based on public
domain elsie-code). Now user can select current time zone
(from the list of time zones described in system tables).
All NOW-like functions honor this time zone, values of TIMESTAMP
type are interpreted as values in this time zone, so now
our TIMESTAMP type behaves similar to Oracle's TIMESTAMP WITH
LOCAL TIME ZONE (or proper PostgresSQL type).
WL#1266 "CONVERT_TZ() - basic time with time zone conversion
function".
Fixed problems described in Bug #2336 (Different number of warnings
when inserting bad datetime as string or as number). This required
reworking of datetime realted warning hadling (they now generated
at Field object level not in conversion functions).
Optimization: Now Field class descendants use table->in_use member
instead of current_thd macro.
