CHECK_FIELD_IGNORE was treated as CHECK_FIELD_ERROR_FOR_NULL;
UPDATE...SET...NULL on NOT NULL fields behaved differently after
a trigger.
Now distinguishes between IGNORE and ERROR_FOR_NULL and save/restores
check-field options.
mysql-test/r/trigger.result:
Show that UPDATE...SET...NULL on NOT NULL columns doesn't behave differently
when run after a trigger.
mysql-test/t/trigger.test:
Show that UPDATE...SET...NULL on NOT NULL columns doesn't behave differently
when run after a trigger.
sql/field_conv.cc:
CHECK_FIELD_IGNORE was treated as CHECK_FIELD_ERROR_FOR_NULL.
Distinguish between the two.
sql/sp_head.cc:
Raise error as needed.
sql/sql_class.cc:
Save and restore check-fields options.
sql/sql_class.h:
Make room so we can save check-fields options.
sql/sql_insert.cc:
Raise error as needed.
A failed REVOKE statement is logged with error=0, thus causing
the slave to stop. The slave should not stop as this was an
expected error. Given that the execution failed on the master as
well the error code should be logged so that the slave can replay
the statement, get an error and compare with the master's
execution outcome. If errors match, then slave can proceed with
replication, as the error it got, when replaying the statement,
was expected.
In this particular case, the bug surfaces because the error code
is pushed to the THD diagnostics area after writing the event to
the binary log. Therefore, it would be logged with the THD
diagnostics area clean, hence its error code would not contain
the correct code.
We fix this by moving the error reporting ahead of the call to
the routine that writes the event to the binary log.
(Original patch by Sinisa Milivojevic)
The YEAR(4) value of 2000 was equal to the "bad" YEAR(4) value of 0000.
The get_year_value() function has been modified to not adjust bad
YEAR(4) value to 2000.
mysql-test/r/type_year.result:
Test case for bug #49910.
mysql-test/t/type_year.test:
Test case for bug #49910.
sql/item_cmpfunc.cc:
Bug #49910: Behavioural change in SELECT/WHERE on YEAR(4) data type
The get_year_value() function has been modified to not adjust bad
YEAR(4) value to 2000.
The problem is that when we make conditon for
grouped result const part of condition is cut off.
It happens because some parts of 'having' condition
which refer to outer join become const after
make_join_statistics. These parts may be lost
during further having condition transformation
in JOIN::exec. The fix is adding 'having'
condition check for const tables after
make_join_statistics is performed.
mysql-test/r/having.result:
test case
mysql-test/t/having.test:
test result
sql/sql_select.cc:
added 'having' condition check for const tables
after make_join_statistics is performed.
DBUG_SYNC_POINT has at least one strong limitation that it's not defined
on all platforms. It has issues cooperating with @@debug.
All in all its functionality is superseded by DEBUG_SYNC facility and
there is no reason to maintain the old less flexible one.
Fixed with adding debug_sync_set_action() function as a facility to set up
a sync-action in the server sources code and re-writing existing simulations
(found 3) to use it.
Couple of tests have been reworked as well.
The patch offers a pattern for setting sync-points in replication threads
where the standard DEBUG_SYNC does not suffice to reach goals.
mysql-test/extra/rpl_tests/rpl_get_master_version_and_clock.test:
rewriting the test from GET_LOCK()-based to DEBUG_SYNC-based;
a pattern of usage DEBUG_SYNC for replication testing is provided.
mysql-test/suite/rpl/r/rpl_get_master_version_and_clock.result:
results are changed.
mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test:
rewriting the test from GET_LOCK()-based to DEBUG_SYNC-based;
limiting the test to run only with MIXED binlog-format as the test last
some 10 secs sensitively contributing to the total of tests run.
mysql-test/suite/rpl/t/rpl_show_slave_running.test:
rewriting the test from GET_LOCK()-based to DEBUG_SYNC-based.
sql/debug_sync.cc:
adding debug_sync_set_action() function as a facility to set up
a sync-action in the server sources code.
sql/debug_sync.h:
externalizing debug_sync_set_action().
sql/item_func.cc:
purging sources from DBUG_SYNC_POINT.
sql/mysql_priv.h:
purging sources from DBUG_SYNC_POINT.
sql/slave.cc:
rewriting failure simulations to base on DEBUG_SYNC rather than GET_LOCK()-based DBUG_SYNC_POINT.
sql/sql_repl.cc:
removing an orphan failure simulation line because no counterpart in tests existing.
Optimizer erroneously translated LEFT JOIN into INNER JOIN.
It leads to cutting rows with NULL right side. It happens
because Item_row uses not_null_tables() method form the
base(Item) class and does not calculate 'null tables'
properly. The fix is adding calculation of 'not null tables'
to Item_row.
mysql-test/r/join_outer.result:
test result
mysql-test/t/join_outer.test:
test case
sql/item_row.cc:
adding calculation of 'not null tables' to Item_row.
sql/item_row.h:
adding calculation of 'not null tables' to Item_row.
The crash happens because of discrepancy between values of
conts_tables and join->const_table_map(make_join_statisctics).
Calculation of conts_tables used condition with
HA_STATS_RECORDS_IS_EXACT flag check. Calculation of
join->const_table_map does not use this flag check.
In case of MERGE table without union with index
the table does not become const table and
thus join_read_const_table() is not called
for the table. join->const_table_map supposes
this table is const and later in make_join_select
this table is used for making&calculation const
condition. As table record buffer is not populated
it leads to crash.
The fix is adding a check if an engine supports
HA_STATS_RECORDS_IS_EXACT flag before updating
join->const_table_map.
mysql-test/r/merge.result:
test result
mysql-test/t/merge.test:
test case
sql/sql_select.cc:
adding a check if an engine supports
HA_STATS_RECORDS_IS_EXACT flag before updating
join->const_table_map.
for InnoDB
The class Field_bit_as_char stores the metadata for the
field incorrecly because bytes_in_rec and bit_len are set
to (field_length + 7 ) / 8 and 0 respectively, while
Field_bit has the correct values field_length / 8 and
field_length % 8.
Solved the problem by re-computing the values for the
metadata based on the field_length instead of using the
bytes_in_rec and bit_len variables.
To handle compatibility with old server, a table map
flag was added to indicate that the bit computation is
exact. If the flag is clear, the slave computes the
number of bytes required to store the bit field and
compares that instead, effectively allowing replication
*without conversion* from any field length that require
the same number of bytes to store.
mysql-test/suite/rpl/t/rpl_typeconv_innodb.test:
Adding test to check compatibility for bit field
replication when using InnoDB
sql/field.cc:
Extending compatible_field_size() with flags from
table map to allow fields to check master info.
sql/field.h:
Extending compatible_field_size() with flags from
table map to allow fields to check master info.
sql/log.cc:
Removing table map flags since they are not used
outside table map class.
sql/log_event.cc:
Removing flags parameter from table map constructor
since it is not used and does not have to be exposed.
sql/log_event.h:
Adding flag to denote that bit length for bit field type
is exact and not potentially rounded to even bytes.
sql/rpl_utility.cc:
Adding fields to table_def to store table map flags.
sql/rpl_utility.h:
Removing obsolete comment and adding flags to store
table map flags from master.
definition at engine
If a single ALTER TABLE contains both DROP INDEX and ADD INDEX using
the same index name (a.k.a. index modification) we need to disable
in-place alter table because we can't ask the storage engine to have
two copies of the index with the same name even temporarily (if we
first do the ADD INDEX and then DROP INDEX) and we can't modify
indexes that are needed by e.g. foreign keys if we first do
DROP INDEX and then ADD INDEX.
Fixed the problem by disabling in-place ALTER TABLE for these cases.
concurrent I_S query
There were two problem:
1) MYSQL_LOCK_IGNORE_FLUSH also ignored name locks
2) there was a race between abort_and_upgrade_locks and
alter_close_tables
(i.e. remove_table_from_cache and
close_data_files_and_morph_locks)
Which allowed the table to be opened with MYSQL_LOCK_IGNORE_FLUSH flag
resulting in renaming a partition that was already in use,
which could cause the table to be unusable.
Solution was to not allow IGNORE_FLUSH to skip waiting for
a named locked table.
And to not release the LOCK_open mutex between the
calls to remove_table_from_cache and
close_data_files_and_morph_locks by merging the functions
abort_and_upgrade_locks and alter_close_tables.
mysql-test/suite/parts/r/partition_debug_sync_innodb.result:
Bug#50561: ALTER PARTITIONS does not have adequate lock, breaks with
concurrent I_S query
Added test result
mysql-test/suite/parts/t/partition_debug_sync_innodb-master.opt:
Bug#50561: ALTER PARTITIONS does not have adequate lock, breaks with
concurrent I_S query
Added test option
mysql-test/suite/parts/t/partition_debug_sync_innodb.test:
Bug#50561: ALTER PARTITIONS does not have adequate lock, breaks with
concurrent I_S query
Added test file
sql/authors.h:
Bug#50561: ALTER PARTITIONS does not have adequate lock, breaks with
concurrent I_S query
Time to be acknowledged :)
sql/ha_partition.cc:
Bug#50561: ALTER PARTITIONS does not have adequate lock, breaks with
concurrent I_S query
Added DEBUG_SYNC for deterministic testing
sql/mysql_priv.h:
Bug#50561: ALTER PARTITIONS does not have adequate lock, breaks with
concurrent I_S query
Renamed function since merging alter_close_tables into
abort_and_upgrade_lock.
sql/sql_base.cc:
Bug#50561: ALTER PARTITIONS does not have adequate lock, breaks with
concurrent I_S query
Changed MYSQL_LOCK_IGNORE_FLUSH to not ignore name locks
(open_placeholder).
Merged alter_close_tables into abort_and_upgrade_locks
(and added _and_close_table to the name)
to not release LOCK_open between remove_table_from_cache
and close_data_files_and_morph_locks.
Added DEBUG_SYNC for deterministic testing.
sql/sql_partition.cc:
Bug#50561: ALTER PARTITIONS does not have adequate lock, breaks with
concurrent I_S query
Removed alter_close_tables, (merged it into
abort_and_upgrad_lock) so that LOCK_open never is released
between remove_table_from_cache and
close_data_files_and_morph_locks.
sql/sql_show.cc:
Bug#50561: ALTER PARTITIONS does not have adequate lock, breaks with
concurrent I_S query
Added DEBUG_SYNC for deterministic testing
NULL column for NULL
The optimization to read MIN() and MAX() values from an
index did not properly handle comparisons with NULL
values. Fixed by giving up the particular optimization step
if there are non-NULL safe comparisons with NULL values, as
the result is NULL anyway.
Also, Oracle copyright notice was added to all files.
Base Tables
The type inferrence of a view column caused the result to be
interpreted as the wrong type: DATE colums were interpreted
as TIME and TIME as DATETIME. This happened because view
columns are represented by Item_ref objects as opposed to
Item_field's. Item_ref had no method for retrieving a TIME
value and thus was forced to depend on the default
implementation for any expression, which caused the
expression to be evaluated as a string and then parsed into
a TIME/DATETIME value.
Fixed by letting Item_ref classes forward the request for a
TIME value to the referred Item - which is a field in this
case - this reads the TIME value directly without
conversion.
SunStudio
SunStudio compilers of late warn about methods that might hide
methods in base classes due to the use of overloading combined
with overriding. SunStudio also warns about variables defined
in local socpe or method arguments that have the same name as
a member attribute of the class.
This patch renames methods that might hide base class methods,
to make it easier both for humans and compilers to see what is
actually called. It also renames variables in local scope.
sql/field.cc:
Local scope variable or method argument same as class
attribute.
sql/item_cmpfunc.cc:
Local scope variable or method argument same as class
attribute.
sql/item_create.cc:
Renaming base class create() to create_func().
sql/item_create.h:
Renaming base class create() to create_func().
sql/protocol.cc:
Local scope variable or method argument same as class
attribute.
sql/sql_profile.cc:
Local scope variable or method argument same as class
attribute.
sql/sql_select.cc:
Local scope variable or method argument same as class
attribute.
sql/sql_yacc.yy:
Renaming base class create() to create_func().
storage/federated/ha_federated.cc:
Local scope variable or method argument same as class
attribute.
storage/myisammrg/ha_myisammrg.cc:
Local scope variable or method argument same as class
attribute.
(regression)
Problem was that partition pruning did not exclude the
last partition if the range was beyond it
(i.e. not using MAXVALUE)
Fix was to not include the last partition if the
partitioning function value was not within the partition
range.
mysql-test/r/partition_innodb.result:
Bug#51830: Incorrect partition pruning on range partition
(regression)
Updated result
mysql-test/r/partition_pruning.result:
Bug#51830: Incorrect partition pruning on range partition
(regression)
Updated result
mysql-test/t/partition_innodb.test:
Bug#51830: Incorrect partition pruning on range partition
(regression)
Added test for pruning in InnoDB, since it does not show
for MyISAM due to 'Impossible WHERE noticed after reading
const tables'.
mysql-test/t/partition_pruning.test:
Bug#51830: Incorrect partition pruning on range partition
(regression)
Added test
sql/sql_partition.cc:
Bug#51830: Incorrect partition pruning on range partition
(regression)
Also increase the partition id if not inside the last partition
(and no MAXVALUE is defined).
Added comments and DBUG_ASSERT.
SET autocommit=1 while XA transaction is active may
cause various side effects, including memory corruption
and server crash.
The problem is that SET autocommit=1 and further queries
attempt to commit local transaction, whereas XA transaction
is still active.
As local and XA transactions are mutually exclusive, this
patch forbids enabling autocommit mode while XA transaction
is active.
mysql-test/r/xa.result:
A test case for BUG#51342.
mysql-test/t/xa.test:
A test case for BUG#51342.
sql/set_var.cc:
Forbid enabling autocommit mode while XA transaction is
active.
MySQL uses two source layouts when building : the bzr
layout and the source package layout.
The previous fix for bug 35250 contained 1 change that is
valid for both modes and a number of changes that are valid
only for the bzr source layout.
The important thing was to fix the source package layout.
And for this the change in configure.in was sufficient.
It's not trivial (and not requested by this bug) to support
VPATH builds from the bzr trees.
This is why the other changes are reverted and the change to
fix the VPATH build for source distributions is left intact.
The problem was that killing a query during the optimization
phase of a subselect would lead to crashes. The root of the
problem is that the subselect execution engine ignores failures
(eg: killed) during the optimization phase (JOIN::optimize),
leading to a crash once the subquery is executed due to
partially initialized structures (in this case a join tab).
The optimal solution would be to cleanup certain optimizer
structures if the optimization phase fails, but currently
there is no infrastructure to properly to track and cleanup
the structures. To workaround the whole problem one somewhat
good solution is to avoid executing a subselect if the query
has been killed. Cutting short any problems caused by failures
during the optimization phase.
sql/item_subselect.cc:
Do not execute a subselect if the session or query has been killed.
The problem was that UNINSTALL PLUGIN wasn't performing privilege
checks before removing a plugin. Any user (including users without
any kind of privileges) could uninstall any plugin.
The solution is to verify if the user has the DELETE privilege for
the mysql.plugin table before uninstalling a plugin.
mysql-test/r/plugin_not_embedded.result:
Add test case result for Bug#51770.
mysql-test/t/plugin_not_embedded-master.opt:
Add example plugin path.
mysql-test/t/plugin_not_embedded.test:
Add test case for Bug#51770.
Skip embedded as test relies on privileges checks.
The problem is that Item_direct_view_ref which is inherited
from Item_ident updates orig_table_name and table_name with
the same values. The fix is introduction of new constructor
into Item_ident and up which updates orig_table_name and
table_name separately.
mysql-test/r/metadata.result:
test case
mysql-test/t/metadata.test:
test case
sql/item.cc:
new constructor which updates
orig_table_name and table_name
separately.
sql/item.h:
new constructor which updates
orig_table_name and table_name
separately.
sql/table.cc:
used new constructor
the fill_schema_processlist function accesses THD::query() without proper protection
so the parallel thread killing can lead to access to the freed meemory.
per-file comments:
sql/sql_load.cc
Bug#51377 Crash in information_schema / processlist on concurrent DDL workload
the THD::set_query_inner() call needs to be protected.
But here we don't need to change the original thd->query() at all.
sql/sql_show.cc
Bug#51377 Crash in information_schema / processlist on concurrent DDL workload
protect the THD::query() access with the THD::LOCK_thd_data mutex.
The problem is that not all column names retrieved from a SELECT
statement can be used as view column names due to length and format
restrictions. The server failed to properly check the conformity
of those automatically generated column names before storing the
final view definition on disk.
Since columns retrieved from a SELECT statement can be anything
ranging from functions to constants values of any format and length,
the solution is to rewrite to a pre-defined format any names that
are not acceptable as a view column name.
The name is rewritten to "Name_exp_%u" where %u translates to the
position of the column. To avoid this conversion scheme, define
explict names for the view columns via the column_list clause.
Also, aliases are now only generated for top level statements.
mysql-test/include/view_alias.inc:
Add test case for Bug#40277
mysql-test/r/compare.result:
Bug#40277: SHOW CREATE VIEW returns invalid SQL
mysql-test/r/group_by.result:
Bug#40277: SHOW CREATE VIEW returns invalid SQL
mysql-test/r/ps.result:
Bug#40277: SHOW CREATE VIEW returns invalid SQL
mysql-test/r/subselect.result:
Bug#40277: SHOW CREATE VIEW returns invalid SQL
mysql-test/r/subselect3.result:
Bug#40277: SHOW CREATE VIEW returns invalid SQL
mysql-test/r/type_datetime.result:
Bug#40277: SHOW CREATE VIEW returns invalid SQL
mysql-test/r/union.result:
Bug#40277: SHOW CREATE VIEW returns invalid SQL
mysql-test/r/view.result:
Add test case result for Bug#40277
mysql-test/r/view_alias.result:
Add test case result for Bug#40277
mysql-test/t/view_alias.test:
Add test case for Bug#40277
sql/sql_view.cc:
Check if auto generated column names are conforming. Also, the
make_unique_view_field_name function is not used as it uses the
original name to construct a new one, which does not work if the
name is invalid.
The problem was that bits of the destructive equality propagation
optimization weren't being undone after the execution of a stored
program. Modifications to the parse tree that are based on transient
properties must be undone to enable the re-execution of stored
programs.
The solution is to cleanup any references to predicates generated
by the equality propagation during the execution of a stored program.
mysql-test/r/trigger.result:
Add test case result for Bug#51650.
mysql-test/t/trigger.test:
Add test case for Bug#51650.
sql/item.cc:
Remove reference to a equality predicate.
auto_increment on duplicate entry
The bug was that when INSERT_ID was used and the storage
engine was told to release any reserved but not used
auto_increment values, it set the highest auto_increment
value to INSERT_ID.
The fix was to check if the auto_increment value was forced
by user (INSERT_ID) or by slave-thread, i.e. not auto-
generated. So that it is only allowed to release generated
values.
mysql-test/r/partition_error.result:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
updated result
mysql-test/suite/parts/inc/partition_auto_increment.inc:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
Added test
mysql-test/suite/parts/r/partition_auto_increment_archive.result:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
Added result, note that archive does only allow increasing
auto_increment values
mysql-test/suite/parts/r/partition_auto_increment_blackhole.result:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
Added result, note that blackhole accepts all inserts :)
mysql-test/suite/parts/r/partition_auto_increment_innodb.result:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
Added result, note that innodb rolls back inserts on error,
but keeps the auto_increment value.
mysql-test/suite/parts/r/partition_auto_increment_memory.result:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
Added result, note that memory and myisam inserts all rows
before the error.
mysql-test/suite/parts/r/partition_auto_increment_myisam.result:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
Added result, note that memory and myisam inserts all rows
before the error.
mysql-test/suite/parts/r/partition_auto_increment_ndb.result:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
Added result, note that NDB does not seem to handle
INSERT_ID as other engines. (Martin will look into it).
mysql-test/t/partition_error.test:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
Added test
sql/ha_partition.cc:
Bug#50392: insert_id is not reset for partitioned tables
auto_increment on duplicate entry
If the next_insert_id comes from non generated (i.e
forced by INSERT_ID or slave-thread) then we cannot
lower the reserved auto_increment value, since it have
not reserved any values.
consider clustered primary keys
Choosing a shortest index for the covering index scan,
the optimizer ignored the fact, that the clustered primary
key read involves whole table data.
The find_shortest_key function has been modified to
take into account that fact that a clustered PK has a
longest key of possible covering indices.
mysql-test/r/innodb_mysql.result:
Test case for bug #39653.
mysql-test/t/innodb_mysql.test:
Test case for bug #39653.
sql/sql_select.cc:
Bug #39653: find_shortest_key in sql_select.cc does not
consider clustered primary keys
The find_shortest_key function has been modified to
take into account that fact that a clustered PK has a
longest key of possible covering indices.
There was no check for foreign keys when altering partitioned
tables.
Added check for FK when altering partitioned tables.
mysql-test/r/partition_innodb.result:
Bug#50104: Partitioned table with just 1 partion works with fk
Updated test result
mysql-test/t/partition_innodb.test:
Bug#50104: Partitioned table with just 1 partion works with fk
Added test for adding FK on partitioned tables (both 1 and 2
partitions)
sql/sql_partition.cc:
Bug#50104: Partitioned table with just 1 partion works with fk
Disabled adding foreign key when altering a partitioned table.
Problem was block_size on partitioned tables was not set,
resulting in keys_per_block was not correct which affects
the cost calculation for read time of indexes (including
cost for group min/max).Which resulted in a bad optimizer
decision.
Fixed by setting stats.block_size correctly.
mysql-test/r/partition_range.result:
Bug#48229: group by performance issue of partitioned table
Added result
mysql-test/t/partition_range.test:
Bug#48229: group by performance issue of partitioned table
Added test
sql/ha_partition.cc:
Bug#48229: group by performance issue of partitioned table
Added missing assignment of stats.block_size.
mode
When the master was executing in sql_mode='traditional' (which
implies that really_abort_on_warning returns TRUE - because of
MODE_STRICT_ALL_TABLES), the error code (ER_DUP_ENTRY in the
reported case) was not being set in the
Query_log_event. Therefore, even if a failure was to be expected
when replaying the statement on the slave, a failure would occur,
because the Query_log_event was not transporting the expected
error code, but 0 instead.
This was because when the master was getting the error code to
set it in the Query_log_event, the executing thread would be
assumed to have been killed:
THD::killed==THD::KILL_BAD_DATA. This would make the error code
fetch routine not to check thd->main_da.sql_errno(), but instead
the thd->killed value. What's more, is that the server would
thd->killed value if thd->killed == THD::KILL_BAD_DATA and return
0 instead. So this is a double inconsistency, as the we should
not even check thd->killed but rather thd->main_da.sql_errno().
We fix this by extending the condition used to choose whether to
check the thd->main_da.sql_errno() or thd->killed, so that it
takes into consideration the case when:
thd->killed==THD::KILL_BAD_DATA.
+ failing statements
Implicit DROP event for temporary table is not getting
LOG_EVENT_THREAD_SPECIFIC_F flag, because, in the previous
executed statement in the same thread, which might even be a
failed statement, the thread_specific_used flag is set to
FALSE (in mysql_reset_thd_for_next_command) and not set to TRUE
before connection is shutdown. This means that implicit DROP
event will take the FALSE value from thread_specific_used and
will not set LOG_EVENT_THREAD_SPECIFIC_F in the event header. As
a consequence, mysqlbinlog will not print the pseudo_thread_id
from the DROP event, because one of the requirements for the
printout is that this flag is set to TRUE.
We fix this by setting thread_specific_used whenever we are
binlogging a DROP in close_temporary_tables, and resetting it to
its previous value afterward.
If an outer query is broken, a subquery might not even get set up.
EXPLAIN EXTENDED did not expect this and merrily tried to de-ref all
of the half-setup info.
We now catch this case and print as much as we have, as it doesn't cost us
anything (doesn't make regular execution slower).
backport from 5.1
mysql-test/r/explain.result:
Show that EXPLAIN EXTENDED with subquery and illegal out query doesn't crash.
Show also that SHOW WARNINGS will render an additional Note in the hope of
being, well, helpful.
mysql-test/t/explain.test:
If we have only half a query for EXPLAIN EXTENDED to print (i.e.,
incomplete subquery info as outer query is illegal), we should
provide the user with as much info as we easily can if they ask
for it. What we should not do is crash when they come asking for
help, that violates etiquette in some countries.
sql/item_subselect.cc:
If the sub-query's actually set up, print it. Otherwise, elide.
This patch fixes some typos and poorly formulated sentences in
the output from mysqld --help --verbose.
Some of the problems described in the bug report are already
handled by the patch for Bug#49447, and are therefore not
included in this patch.