query
Problem:
There was a wrong context assigned to the columns that were added in insert_fields()
when expanding a '*'. When this is done in a prepared statement it causes
fix_fields() to fail to find the table that these columns reference.
Actually the right context is set in setup_natural_join_row_types() called at the
end of setup_tables(). However when executed in a context of a prepared statement
setup_tables() resets the context, but setup_natural_join_row_types() was not
setting it to the correct value assuming it has already done so.
Solution:
The top-most, left-most NATURAL/USING join must be set as a
first_name_resolution_table in context even when operating on prepared statements.
read buffer
Setting read buffer to values greater than SSIZE_MAX results in
unexpected behavior.
According to read(2) manual:
If count is greater than SSIZE_MAX, the result is unspecified.
Set upper limit for read_buffer_size and read_rnd_buffer_size to
SSIZE_MAX.
The st_lex::which_check_option_applicable() function controls for which
statements WITH CHECK OPTION clause should be taken into account. REPLACE and
REPLACE_SELECT wasn't in the list which results in allowing REPLACE to insert
wrong rows in a such view.
The st_lex::which_check_option_applicable() now includes REPLACE and
REPLACE_SELECT in the list of statements for which WITH CHECK OPTION clause is
applicable.
To calculate its max_length the CONCAT() function is simply sums max_lengths
of its arguments but when the collation of an argument differs from the
collation of the CONCAT() max_length will be wrong. This may lead to a data
truncation when a tmp table is used, in UNIONS for example.
The Item_func_concat::fix_length_and_dec() function now recalculates the
max_length of an argument when the mbmaxlen of the argument differs from the
mbmaxlen of the CONCAT().
fix: return db name for I_S.TABLES(and others) in original letter case.
if mysql starts with lower_case_table_names=1 | 2 then original db name is converted
to lower case(for I_S tables). It happens when we perform add_table_to_list.
to avoid this we make a copy of original db name and use the copy hereafter.
The bug report revealed two problems related to min/max optimization:
1. If the length of a constant key used in a SARGable condition for
for the MIN/MAX fields is greater than the length of the field an
unwanted warning on key truncation is issued;
2. If MIN/MAX optimization is applied to a partial index, like INDEX(b(4))
than can lead to returning a wrong result set.
3.23 regression test failure
The member SEL_ARG::min_flag was not initialized,
due to which the condition for no GEOM_FLAG in function
key_or did not choose "Range checked for each record" as
the correct access method.
ALTER TABLE crashes
Executing fast alter table (one that doesn't need to copy data)
on tables created by mysql versions prior to 4.0.25 could result
in posterior server crash when accessing these tables.
There was a bug prior to mysql-4.0.25. Number of null fields was
calculated incorrectly. As a result frm and data files gets out of
sync after fast alter table. There is no way to determine by which
mysql version (in 4.0 and 4.1 branches) table was created, thus we
disable fast alter table for all tables created by mysql versions
prior to 5.0 branch.
See BUG#6236.
Only check for FN_DEVCHAR in filenames if FN_DEVCHAR is defined.
This allows to use table names with ":" on non windows platforms.
On Windows platform get an error if you use table name that contains FN_DEVCHAR
- Include prefix files that renames all public functions in yaSSLs
OpenSSL API to ya<function_name>. They will otherwise conflict
with OpenSSL functions if loaded by an application that uses OpenSSL
as well as libmysqlclient with yaSSL support.
Two threads both try a shutdown sequence which creates a race to the
de-init/free of certain resources.
This exists in similar form in the client as 17926: "mysql.exe crashes
when ctrl-c is pressed in windows."
Bug#18282 "INFORMATION_SCHEMA.TABLES provides inconsistent info about invalid views"
This bug caused crashes or resulted in wrong data being returned
when one tried to obtain information from I_S tables about views
using stored functions.
It was caused by the fact that we were using LEX representing
statement which were doing select from I_S tables as active LEX
when contents of I_S table were built. So state of this LEX both
affected and was affected by open_tables() calls which happened
during this process. This resulted in wrong behavior and in
violations of some of invariants which caused crashes.
This fix tries to solve this problem by properly saving/resetting
and restoring part of LEX which affects and is affected by the
process of opening tables and views in get_all_tables() routine.
To simplify things we separated this part of LEX in a new class
and made LEX its descendant.
The IN() function uses agg_cmp_type() to aggregate all types of its arguments
to find out some common type for comparisons. In this particular case the
char() and the int was aggregated to double because char() can contain values
like '1.5'. But all strings which do not start from a digit are converted to
0. thus 'a' and 'z' become equal.
This behaviour is reasonable when all function arguments are constants. But
when there is a field or an expression this can lead to false comparisons. In
this case it makes more sense to coerce constants to the type of the field
argument.
The agg_cmp_type() function now aggregates types of constant and non-constant
items separately. If some non-constant items will be found then their
aggregated type will be returned. Thus after the aggregation constants will be
coerced to the aggregated type.
The order of acquiring LOCK_mysql_create_db
and wait_if_global_read_lock() was wrong. It could happen
that a thread held LOCK_mysql_create_db while waiting for
the global read lock to be released. The thread with the
global read lock could try to administrate a database too.
It would first try to lock LOCK_mysql_create_db and hang...
The check if the current thread has the global read lock
is done in wait_if_global_read_lock(), which could not be
reached because of the hang in LOCK_mysql_create_db.
Now I exchanged the order of acquiring LOCK_mysql_create_db
and wait_if_global_read_lock(). This makes
wait_if_global_read_lock() fail with an error message for
the thread with the global read lock. No deadlock happens.
In multi-table delete a table for delete can't be used for selecting in
subselects. Appropriate error was raised but wasn't checked which leads to a
crash at the execution phase.
The mysql_execute_command() now checks for errors before executing select
for multi-delete.