into moonlight.home:/home/tomash/src/mysql_ab/mysql-5.1-bug9953
mysql-test/r/sp-error.result:
Auto merged
mysql-test/r/view.result:
Auto merged
sql/item_timefunc.cc:
Auto merged
sql/lock.cc:
Auto merged
sql/log_event.cc:
Auto merged
sql/mysql_priv.h:
Auto merged
sql/set_var.cc:
Auto merged
sql/sp.cc:
Auto merged
sql/sql_base.cc:
Auto merged
sql/sql_help.cc:
Auto merged
sql/sql_lex.cc:
Auto merged
sql/sql_lex.h:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/sql_show.cc:
Auto merged
sql/sql_view.cc:
Auto merged
sql/table.cc:
Auto merged
sql/tztime.cc:
Auto merged
storage/myisam/ha_myisam.cc:
Auto merged
sql/sql_yacc.yy:
SCCS merged
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.
mysql-test/r/help.result:
Update result.
mysql-test/r/lock.result:
Update result.
mysql-test/r/sp-error.result:
Update result.
mysql-test/r/timezone2.result:
Add result for bug#9953: CONVERT_TZ requires mysql.time_zone_name
to be locked.
mysql-test/r/view.result:
Update result: use table t3 rather than utilize MySQL system table.
mysql-test/t/help.test:
Test that we can use HELP even under LOCK TABLES.
mysql-test/t/lock.test:
Test LOCK TABLE on system tables.
mysql-test/t/timezone2.test:
Add test case for bug#9953: CONVERT_TZ requires mysql.time_zone_name
to be locked.
mysql-test/t/view.test:
Update test: use table t3 rather that utilize MySQL system table.
sql/handler.h:
Fix comment for 'count' parameter of check_if_locking_is_allowed().
Add 'current' and 'system_count' parameters.
sql/item_create.cc:
We no longer have LEX::add_time_zone_tables_to_query_tables().
sql/item_timefunc.cc:
We no longer have LEX::time_zone_tables_used, so
Item_func_convert_tz::fix_fields() became the same as base
Item_date_func::fix_fields().
my_tz_find() no longer takes table list, but takes THD pointer now.
sql/item_timefunc.h:
Remove dead field and method.
sql/lock.cc:
Pass values for 'current' and 'system_count' to
check_if_locking_is_allowed().
sql/log_event.cc:
We no longer have my_tz_find_with_opening_tz_tables(), its functions is
performed by my_tz_find().
sql/mysql_priv.h:
Add functions to work with MySQL system tables.
sql/set_var.cc:
my_tz_find() no longer takes table list, but takes THD pointer now.
sql/sp.cc:
Remove close_proc_table(). Use close_system_tables() instead.
Use open_system_tables_for_read() and open_system_table_for_update().
sql/sp.h:
Remove close_proc_table() declaration.
sql/sql_base.cc:
Add implementation of open_system_tables_for_read(),
close_system_tables(), open_system_table_for_update().
sql/sql_help.cc:
Operate on MySQL system tables mysql.help_* with
open_system_tables_for_read() and close_system_tables() to allow the
usage of HELP statement under LOCK TABLES.
sql/sql_lex.cc:
Remove LEX::time_zone_tables_used and
LEX::add_time_zone_tables_to_query_tables() which are no longer used.
sql/sql_lex.h:
Remove LEX::time_zone_tables_used and
LEX::add_time_zone_tables_to_query_tables() which are no longer used.
sql/sql_parse.cc:
Remove references to LEX::time_zone_tables_used and
my_tz_check_n_skip_implicit_tables() which are no longer used.
sql/sql_show.cc:
Use close_system_tables() instead of removed close_proc_table().
sql/sql_view.cc:
LEX::time_zone_tables_used is no longer there.
sql/sql_yacc.yy:
LEX::add_time_zone_tables_to_query_tables() is no longer there.
sql/table.cc:
Add more tables that should be treated as MySQL system tables.
sql/share/errmsg.txt:
Change the error message, as now we allow write-locking of several
system tables if not mixed with ordinary tables.
sql/tztime.cc:
Do not add time zone tables to the list of query tables in
tz_init_table_list().
Remove fake_time_zone_tables_list and my_tz_get_tables_list().
In my_tz_init(), open mysql.time_zone_leap_second with
simple_open_n_lock_tables(), but pass time zone name to my_tz_find(),
which will open and close time zone tables as necessary.
In tz_load_from_open_tables() do not call table->use_all_columns(), as
this was already done in open_system_tables_for_read().
my_tz_find() takes THD pointer instead of table list, and calls
open_system_tables_for_read() and close_system_tables() as necessary.
Remove my_tz_find_with_opening_tz_tables().
sql/tztime.h:
Remove declarations of my_tz_get_table_list(),
my_tz_find_with_opening_tz_tables(), fake_time_zone_tables_list,
definition of my_tz_check_n_skip_implicit_tables().
Update prototype for my_tz_find().
storage/csv/ha_tina.cc:
Add new parameters to check_if_locking_is_allowed().
storage/csv/ha_tina.h:
Add new parameters to check_if_locking_is_allowed().
storage/myisam/ha_myisam.cc:
Add new parameters to check_if_locking_is_allowed(). In this
function we count system tables. If there are system tables, but
there are also non-system tables, we report an error.
storage/myisam/ha_myisam.h:
Add new parameters to check_if_locking_is_allowed().
continuation instruction, for CONTINUE exception handlers.
sql/sp_head.cc:
Post review cleanup: use instr::get_cont_dest() to get the instruction
continuation instruction, for CONTINUE exception handlers.
sql/sp_head.h:
Post review cleanup: use instr::get_cont_dest() to get the instruction
continuation instruction, for CONTINUE exception handlers.
into moonlight.home:/home/tomash/src/mysql_ab/mysql-5.1-bug18326
mysql-test/r/ps.result:
Auto merged
mysql-test/t/ps.test:
Auto merged
sql/sql_prepare.cc:
Auto merged
During statement prepare phase the tables were locked as if the
statement is being executed, however this is not necessary.
The solution is to not lock tables on statement prepare phase.
Opening tables is enough to prevent DDL on them, and during statement
prepare we do not access nor modify any data.
mysql-test/r/ps.result:
Add result for bug#18326: Do not lock table for writing during
prepare of statement.
mysql-test/t/ps.test:
Add test case for bug#18326: Do not lock table for writing during
prepare of statement.
sql/sql_prepare.cc:
Do not lock tables on statement prepare phase. Opening tables is
enough to prevent DDL on them, and during statement prepare we do not
access nor modify any data.
Use open_normal_and_derived_tables() for table opening on prepare.
into bodhi.local:/opt/local/work/mysql-5.1-runtime
mysql-test/r/trigger.result:
Auto merged
mysql-test/r/view.result:
Auto merged
mysql-test/t/trigger.test:
Auto merged
sql/log_event.cc:
Auto merged
sql/mysqld.cc:
Auto merged
sql/sp_head.cc:
Auto merged
sql/sp_head.h:
Auto merged
sql/sql_base.cc:
Auto merged
sql/sql_lex.cc:
Auto merged
sql/sql_lex.h:
Auto merged
sql/sql_trigger.cc:
Auto merged
sql/sql_update.cc:
Auto merged
sql/table.cc:
Auto merged
sql/table.h:
Auto merged
sql/sql_class.cc:
Manual merge.
sql/sql_class.h:
Manual merge.
sql/sql_parse.cc:
Manual merge.
sql/sql_prepare.cc:
Manual merge.
sql/sql_yacc.yy:
Manual merge.
into bodhi.local:/opt/local/work/mysql-5.0-26750
sql/mysqld.cc:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/sql_class.h:
Manual merge.
fixes).
The legend: on a replication slave, in case a trigger creation
was filtered out because of application of replicate-do-table/
replicate-ignore-table rule, the parsed definition of a trigger was not
cleaned up properly. LEX::sphead member was left around and leaked
memory. Until the actual implementation of support of
replicate-ignore-table rules for triggers by the patch for Bug 24478 it
was never the case that "case SQLCOM_CREATE_TRIGGER"
was not executed once a trigger was parsed,
so the deletion of lex->sphead there worked and the memory did not leak.
The fix:
The real cause of the bug is that there is no 1 or 2 places where
we can clean up the main LEX after parse. And the reason we
can not have just one or two places where we clean up the LEX is
asymmetric behaviour of MYSQLparse in case of success or error.
One of the root causes of this behaviour is the code in Item::Item()
constructor. There, a newly created item adds itself to THD::free_list
- a single-linked list of Items used in a statement. Yuck. This code
is unaware that we may have more than one statement active at a time,
and always assumes that the free_list of the current statement is
located in THD::free_list. One day we need to be able to explicitly
allocate an item in a given Query_arena.
Thus, when parsing a definition of a stored procedure, like
CREATE PROCEDURE p1() BEGIN SELECT a FROM t1; SELECT b FROM t1; END;
we actually need to reset THD::mem_root, THD::free_list and THD::lex
to parse the nested procedure statement (SELECT *).
The actual reset and restore is implemented in semantic actions
attached to sp_proc_stmt grammar rule.
The problem is that in case of a parsing error inside a nested statement
Bison generated parser would abort immediately, without executing the
restore part of the semantic action. This would leave THD in an
in-the-middle-of-parsing state.
This is why we couldn't have had a single place where we clean up the LEX
after MYSQLparse - in case of an error we needed to do a clean up
immediately, in case of success a clean up could have been delayed.
This left the door open for a memory leak.
One of the following possibilities were considered when working on a fix:
- patch the replication logic to do the clean up. Rejected
as breaks module borders, replication code should not need to know the
gory details of clean up procedure after CREATE TRIGGER.
- wrap MYSQLparse with a function that would do a clean up.
Rejected as ideally we should fix the problem when it happens, not
adjust for it outside of the problematic code.
- make sure MYSQLparse cleans up after itself by invoking the clean up
functionality in the appropriate places before return. Implemented in
this patch.
- use %destructor rule for sp_proc_stmt to restore THD - cleaner
than the prevoius approach, but rejected
because needs a careful analysis of the side effects, and this patch is
for 5.0, and long term we need to use the next alternative anyway
- make sure that sp_proc_stmt doesn't juggle with THD - this is a
large work that will affect many modules.
Cleanup: move main_lex and main_mem_root from Statement to its
only two descendants Prepared_statement and THD. This ensures that
when a Statement instance was created for purposes of statement backup,
we do not involve LEX constructor/destructor, which is fairly expensive.
In order to track that the transformation produces equivalent
functionality please check the respective constructors and destructors
of Statement, Prepared_statement and THD - these members were
used only there.
This cleanup is unrelated to the patch.
sql/log_event.cc:
THD::main_lex is private and should not be used.
sql/mysqld.cc:
Move MYSQLerror to sql_yacc.yy as it depends on LEX headers now.
sql/sql_class.cc:
Cleanup: move main_lex and main_mem_root to THD and Prepared_statement
sql/sql_class.h:
Cleanup: move main_lex and main_mem_root to THD and Prepared_statement
sql/sql_lex.cc:
Implement st_lex::restore_lex()
sql/sql_lex.h:
Declare st_lex::restore_lex().
sql/sql_parse.cc:
Consolidate the calls to unit.cleanup() and deletion of lex->sphead
in mysql_parse (COM_QUERY handler)
sql/sql_prepare.cc:
No need to delete lex->sphead to restore memory roots now in case of a
parse error - this is done automatically inside MYSQLparse
sql/sql_trigger.cc:
This code could lead to double deletion apparently, as in case
of an error lex.sphead was never reset.
sql/sql_yacc.yy:
Trap all returns from the parser to ensure that MySQL-specific cleanup
is invoked: we need to restore the global state of THD and LEX in
case of a parsing error. In case of a parsing success this happens as
part of normal grammar reduction process.
into weblab.(none):/home/marcsql/TREE/mysql-5.0-8407_b
mysql-test/r/view.result:
Auto merged
sql/mysqld.cc:
Auto merged
sql/sp_head.cc:
Auto merged
sql/sp_head.h:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_class.h:
Auto merged
sql/sql_update.cc:
Auto merged
sql/table.cc:
Auto merged
sql/table.h:
Auto merged
sql/sql_base.cc:
Manual merge
into weblab.(none):/home/marcsql/TREE/mysql-5.1-8407-merge
mysql-test/r/information_schema_db.result:
Auto merged
mysql-test/r/view.result:
Auto merged
mysql-test/t/sp.test:
Auto merged
sql/lock.cc:
Auto merged
sql/mysqld.cc:
Auto merged
sql/sp_head.cc:
Auto merged
sql/sp_head.h:
Auto merged
sql/sql_base.cc:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_update.cc:
Auto merged
sql/table.cc:
Auto merged
sql/table.h:
Auto merged
into bodhi.local:/opt/local/work/mysql-5.1-runtime-merge
BitKeeper/deleted/.del-ha_berkeley.cc:
Auto merged
cmd-line-utils/readline/xmalloc.c:
Auto merged
include/my_dbug.h:
Auto merged
mysql-test/mysql-test-run.pl:
Auto merged
mysql-test/t/disabled.def:
Auto merged
server-tools/instance-manager/instance_options.cc:
Auto merged
server-tools/instance-manager/mysqlmanager.cc:
Auto merged
sql/item_cmpfunc.cc:
Auto merged
sql/item_cmpfunc.h:
Auto merged
sql/item_func.cc:
Auto merged
sql/item_subselect.cc:
Auto merged
sql/item_subselect.h:
Auto merged
sql/log.cc:
Auto merged
sql/slave.cc:
Auto merged
sql/sp_head.cc:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_lex.cc:
Auto merged
sql/sql_lex.h:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/sql_repl.cc:
Auto merged
mysql-test/r/subselect.result:
Use local.
sql/ha_ndbcluster.cc:
Use local
storage/archive/ha_archive.cc:
Use local.
support-files/compiler_warnings.supp:
Use local
client/mysql_upgrade.c:
Manual merge.
client/mysqltest.c:
Manual merge.
mysql-test/t/subselect.test:
Manual merge.
sql/field.cc:
Manual merge.
sql/sql_base.cc:
Manual merge.
sql/sql_yacc.yy:
Manual merge.
into bodhi.local:/opt/local/work/mysql-5.1-runtime-merge
mysql-test/t/disabled.def:
Auto merged
sql/handler.cc:
Auto merged
sql/item_func.cc:
Auto merged
sql/mysql_priv.h:
Auto merged
sql/mysqld.cc:
Auto merged
sql/sp_head.cc:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/sql_yacc.yy:
Auto merged
sql/table.h:
Auto merged
mysql-test/r/show_check.result:
Manual merge.
mysql-test/t/show_check.test:
Manual merge.
Bug 18914 (Calling certain SPs from triggers fail)
Bug 20713 (Functions will not not continue for SQLSTATE VALUE '42S02')
Bug 21825 (Incorrect message error deleting records in a table with a
trigger for inserting)
Bug 22580 (DROP TABLE in nested stored procedure causes strange dependency
error)
Bug 25345 (Cursors from Functions)
This fix resolves a long standing issue originally reported with bug 8407,
which affect the behavior of Stored Procedures, Stored Functions and Trigger
in many different ways, causing symptoms reported by all the bugs listed.
In all cases, the root cause of the problem traces back to 8407 and how the
server locks tables involved with sub statements.
Prior to this fix, the implementation of stored routines would:
- compute the transitive closure of all the tables referenced by a top level
statement
- open and lock all the tables involved
- execute the top level statement
"transitive closure of tables" means collecting:
- all the tables,
- all the stored functions,
- all the views,
- all the table triggers
- all the stored procedures
involved, and recursively inspect these objects definition to find more
references to more objects, until the list of every object referenced does
not grow any more.
This mechanism is known as "pre-locking" tables before execution.
The motivation for locking all the tables (possibly) used at once is to
prevent dead locks.
One problem with this approach is that, if the execution path the code
really takes during runtime does not use a given table, and if the table is
missing, the server would not execute the statement.
This in particular has a major impact on triggers, since a missing table
referenced by an update/delete trigger would prevent an insert trigger to run.
Another problem is that stored routines might define SQL exception handlers
to deal with missing tables, but the server implementation would never give
user code a chance to execute this logic, since the routine is never
executed when a missing table cause the pre-locking code to fail.
With this fix, the internal implementation of the pre-locking code has been
relaxed of some constraints, so that failure to open a table does not
necessarily prevent execution of a stored routine.
In particular, the pre-locking mechanism is now behaving as follows:
1) the first step, to compute the transitive closure of all the tables
possibly referenced by a statement, is unchanged.
2) the next step, which is to open all the tables involved, only attempts
to open the tables added by the pre-locking code, but silently fails without
reporting any error or invoking any exception handler is the table is not
present. This is achieved by trapping internal errors with
Prelock_error_handler
3) the locking step only locks tables that were successfully opened.
4) when executing sub statements, the list of tables used by each statements
is evaluated as before. The tables needed by the sub statement are expected
to be already opened and locked. Statement referencing tables that were not
opened in step 2) will fail to find the table in the open list, and only at
this point will execution of the user code fail.
5) when a runtime exception is raised at 4), the instruction continuation
destination (the next instruction to execute in case of SQL continue
handlers) is evaluated.
This is achieved with sp_instr::exec_open_and_lock_tables()
6) if a user exception handler is present in the stored routine, that
handler is invoked as usual, so that ER_NO_SUCH_TABLE exceptions can be
trapped by stored routines. If no handler exists, then the runtime execution
will fail as expected.
With all these changes, a side effect is that view security is impacted, in
two different ways.
First, a view defined as "select stored_function()", where the stored
function references a table that may not exist, is considered valid.
The rationale is that, because the stored function might trap exceptions
during execution and still return a valid result, there is no way to decide
when the view is created if a missing table really cause the view to be invalid.
Secondly, testing for existence of tables is now done later during
execution. View security, which consist of trapping errors and return a
generic ER_VIEW_INVALID (to prevent disclosing information) was only
implemented at very specific phases covering *opening* tables, but not
covering the runtime execution. Because of this existing limitation,
errors that were previously trapped and converted into ER_VIEW_INVALID are
not trapped, causing table names to be reported to the user.
This change is exposing an existing problem, which is independent and will
be resolved separately.
mysql-test/r/information_schema_db.result:
Revised the pre-locking code implementation, aligned the tests.
mysql-test/r/sp-error.result:
Revised the pre-locking code implementation, aligned the tests.
mysql-test/r/sp.result:
Revised the pre-locking code implementation, aligned the tests.
mysql-test/r/trigger.result:
Revised the pre-locking code implementation, aligned the tests.
mysql-test/r/view.result:
Revised the pre-locking code implementation, aligned the tests.
mysql-test/t/sp-error.test:
Revised the pre-locking code implementation, aligned the tests.
mysql-test/t/sp.test:
Revised the pre-locking code implementation, aligned the tests.
mysql-test/t/trigger.test:
Revised the pre-locking code implementation, aligned the tests.
sql/lock.cc:
table->placeholder now checks for schema_table
sql/mysqld.cc:
my_message_sql(): invoke internal exception handlers
sql/sp_head.cc:
exec_open_and_lock_tables(): open and lock tables, or return the
continuation destination of this instruction
sql/sp_head.h:
exec_open_and_lock_tables(): open and lock tables, or return the
continuation destination of this instruction
sql/sql_base.cc:
Prelock_error_handler: delay open table errors until execution
sql/sql_class.cc:
THD: add internal error handler, as an exception mechanism.
sql/sql_class.h:
THD: add internal error handler, as an exception mechanism.
sql/sql_update.cc:
table->placeholder now checks for schema_table
sql/table.cc:
st_table_list::hide_view_error(): masked more errors for view security
sql/table.h:
table->placeholder now checks for schema_table, and unopened tables
sql/sql_yacc.yy:
Rename: YYERROR_UNLESS -> YYABORT_UNLESS
yyerror doesn't have to abort of the parser, whereas this macro
does explicitly call YYABORT.
results)
Before this fix, the function BENCHMARK() would fail to evaluate expressions
like "(select avg(a) from t1)" in debug builds (with an assert),
or would report a time of zero in non debug builds.
The root cause is that evaluation of DECIMAL_RESULT expressions was not
supported in Item_func_benchmark::val_int().
This has been fixed by this change.
mysql-test/r/func_misc.result:
Added support for DECIMAL_RESULT in Item_func_benchmark::val_int()
mysql-test/t/func_misc.test:
Added support for DECIMAL_RESULT in Item_func_benchmark::val_int()
sql/item_func.cc:
Added support for DECIMAL_RESULT in Item_func_benchmark::val_int()
into weblab.(none):/home/marcsql/TREE/mysql-5.0-rt-merge
mysql-test/mysql-test-run.pl:
Auto merged
mysql-test/t/disabled.def:
Auto merged
server-tools/instance-manager/instance_options.cc:
Auto merged
server-tools/instance-manager/mysqlmanager.cc:
Auto merged
sql/item_cmpfunc.cc:
Auto merged
sql/item_cmpfunc.h:
Auto merged
sql/item_subselect.cc:
Auto merged
sql/item_subselect.h:
Auto merged
sql/sp_head.cc:
Auto merged
sql/sql_base.cc:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_lex.cc:
Auto merged
sql/sql_lex.h:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/sql_yacc.yy:
Auto merged
into mysql.com:/nfsdisk1/lars/bk/mysql-5.1-new-rpl
mysql-test/r/mysqlbinlog.result:
Auto merged
mysql-test/r/rpl_replicate_do.result:
Auto merged
mysql-test/t/mysqlbinlog.test:
Auto merged
mysql-test/t/rpl_replicate_do.test:
Auto merged
sql/mysql_priv.h:
Auto merged
sql/mysqld.cc:
Auto merged
sql/sql_repl.cc:
Auto merged
sql/sql_trigger.cc:
Auto merged
sql/sql_trigger.h:
Auto merged
sql/slave.cc:
Manual merge
sql/sql_insert.cc:
Manual merge
sql/sql_parse.cc:
Manual merge
sql/sql_yacc.yy:
Manual merge
into mysql.com:/home/bar/mysql-5.1-rpl
mysql-test/r/mysqlbinlog.result:
Auto merged
mysql-test/t/mysqlbinlog.test:
Auto merged
sql/log_event.cc:
Auto merged
sql/log_event.h:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_class.h:
Auto merged
sql/sql_load.cc:
Auto merged
sql/sql_yacc.yy:
Auto merged
into mysql.com:/nfsdisk1/lars/MERGE/mysql-5.0-merge
sql/field.cc:
Auto merged
sql/log.cc:
Auto merged
sql/slave.cc:
Auto merged
sql/sql_repl.cc:
Auto merged
sql/slave.cc:
Guard declaration of variable to avoid "unused variable" warning.
sql/sql_repl.cc:
Guard declaration of variable to avoid "unused variable" warning.