Bug#41756 "Strange error messages about locks from InnoDB".
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
Unlocking of rows is done by the logic of the nested join loop,
and is unaware of the possible caching that the access method may
have. This could lead to double unlocking, when a row
was unlocked first after reading into the cache, and then
when taken from cache, as well as to unlocking of rows which
were actually used (but taken from cache).
Delegate part of the unlocking logic to the access method,
and in JT_EQ_REF count how many times a record was actually
used in the join. Unlock it only if it's usage count is 0.
Implemented review comments.
mysql-test/r/innodb_lock_wait_timeout_1.result:
Update results (Bug41756).
mysql-test/t/innodb_lock_wait_timeout_1.test:
Add a test case (Bug#41756).
sql/item_subselect.cc:
Complete struct READ_RECORD initialization with a new
member to unlock records.
sql/records.cc:
Extend READ_RECORD API with a method to unlock read records.
sql/sql_select.cc:
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
sql/sql_select.h:
Add members to TABLE_REF to count TABLE_REF buffer usage count.
sql/structs.h:
Update declarations.
Bug#41756 "Strange error messages about locks from InnoDB".
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
Unlocking of rows is done by the logic of the nested join loop,
and is unaware of the possible caching that the access method may
have. This could lead to double unlocking, when a row
was unlocked first after reading into the cache, and then
when taken from cache, as well as to unlocking of rows which
were actually used (but taken from cache).
Delegate part of the unlocking logic to the access method,
and in JT_EQ_REF count how many times a record was actually
used in the join. Unlock it only if it's usage count is 0.
Implemented review comments.
mysql-test/r/bug41756.result:
Add result file (Bug#41756)
mysql-test/t/bug41756-master.opt:
Use --innodb-locks-unsafe-for-binlog, as in 5.0 just
using read_committed isolation is not sufficient to
reproduce the bug.
mysql-test/t/bug41756.test:
Add a test file (Bug#41756)
sql/item_subselect.cc:
Complete struct READ_RECORD initialization with a new
member to unlock records.
sql/records.cc:
Extend READ_RECORD API with a method to unlock read records.
sql/sql_select.cc:
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
sql/sql_select.h:
Add members to TABLE_REF to count TABLE_REF buffer usage count.
sql/structs.h:
Update declarations.
For application compatibility reasons MySQL converts "<autoincrement_column> IS NULL"
predicates to "<autoincrement_column> = LAST_INSERT_ID()" in the first SELECT following an
INSERT regardless of whether they're top level predicates or not. This causes wrong and
obscure results when these predicates are combined with others on the same columns. Fixed
by only doing the transformation on a single top-level predicate if a special SQL mode is
turned on (sql_auto_is_null).
Also made sql_auto_is_null off by default.
per-file comments:
mysql-test/r/func_isnull.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test result updated
mysql-test/t/func_isnull.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test case added
sql/mysqld.cc
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
sql_auto_is_null now is OFF by default.
sql/sql_select.cc
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
remove_eq_conds() split in two parts - one only checks the upper condition,
the req_remove_eq_conds() recursively checks all the condition tree.
mysql-test/extra/rpl_tests/rpl_insert_id.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test fixed (set the sql_auto_is_null variable)
mysql-test/r/mysqlbinlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/mysqlbinlog2.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/odbc.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/query_cache.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/user_var-binlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/binlog/r/binlog_row_ctype_ucs.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/binlog/r/binlog_stm_ctype_ucs.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_insert_id.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_row_mysqlbinlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_sp.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/t/odbc.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test fixed (set the sql_auto_is_null variable)
with temporary tables
There were two problems the test case from this bug was
triggering:
1. JOIN::rollup_init() was supposed to wrap all constant Items
into another object for queries with the WITH ROLLUP modifier
to ensure they are never considered as constants and therefore
are written into temporary tables if the optimizer chooses to
employ them for DISTINCT/GROUP BY handling.
However, JOIN::rollup_init() was called before
make_join_statistics(), so Items corresponding to fields in
const tables could not be handled as intended, which was
causing all kinds of problems later in the query execution. In
particular, create_tmp_table() assumed all constant items
except "hidden" ones to be removed earlier by remove_const()
which led to improperly initialized Field objects for the
temporary table being created. This is what was causing crashes
and valgrind errors in storage engines.
2. Even when the above problem had been fixed, the query from
the test case produced incorrect results due to some
DISTINCT/GROUP BY optimizations being performed by the
optimizer that are inapplicable in the WITH ROLLUP case.
Fixed by disabling inapplicable DISTINCT/GROUP BY optimizations
when the WITH ROLLUP modifier is present, and splitting the
const-wrapping part of JOIN::rollup_init() into a separate
method which is now invoked after make_join_statistics() when
the const tables are already known.
mysql-test/r/olap.result:
Added a test case for bug #48131.
mysql-test/t/olap.test:
Added a test case for bug #48131.
sql/sql_select.cc:
1. Disabled inapplicable DISTINCT/GROUP BY optimizations when
the WITH ROLLUP modifier is present.
2. Split the const-wrapping part of JOIN::rollup_init() into a
separate method.
sql/sql_select.h:
Added rollup_process_const_fields() declaration.
subquery returning multiple rows
Error handling was missing when handling subqueires in WHERE
and when assigning a SELECT result to a @variable.
This caused crash(es).
Fixed by adding error handling code to both the WHERE
condition evaluation and to assignment to an @variable.
having clause...
The fix for bug 46184 was not very complete. It was not covering
views using temporary tables and multiple tables in a FROM clause.
Fixed by reverting the fix for 46184 and making a more general
check that is checking at the right execution stage and for all
of the non-supported cases.
Now PROCEDURE ANALYZE on non-top level SELECT is also forbidden.
Updated the analyse.test and subselect.test accordingly.
Queries with nested outer joins may lead to crashes or
bad results because an internal data structure is not handled
correctly.
The optimizer uses bitmaps of nested JOINs to determine
if certain table can be placed at a certain place in the
JOIN order.
It does maintain a bitmap describing in which JOINs
last placed table is nested.
When it puts a table it makes sure the bit of every JOIN that
contains the table in question is set (because JOINs can be nested).
It does that by recursively setting the bit for the next enclosing
JOIN when this is the first table in the JOIN and recursively
resetting the bit if it's the last table in the JOIN.
When it removes a table from the join order it should do the
opposite : recursively unset the bit if it's the only remaining
table in this join and and recursively set the bit if it's removing
the last table of a JOIN.
There was an error in how the bits was set for the upper levels :
when removing a table it was setting the bit for all the enclosing
nested JOINs even if there were more tables left in the current JOIN
(which practically means that the upper nested JOINs were not affected).
Fixed by stopping the recursion at the relevant level.
mysql-test/r/join.result:
Bug #42116: test case
mysql-test/t/join.test:
Bug #42116: test case
sql/sql_select.cc:
Bug #41116: don't go up and set the bits if more tables in
at the current JOIN level
Item_sum::set_aggregator() may be called multiple times during query preparation.
On subsequent calls: verify that the aggregator type is the same,
and re-use the existing Aggregator.
sql/item_sum.cc:
In Item_sum::set_aggregator(): re-use existing Aggregator if already set.
Remove some friend declarations, add some accessor functions.
Cleanup some DBUG_ENTER and DBUG_RETURN code.
sql/item_sum.h:
Make some member fields private, add accessors instead.
Remove some un-necessary friend declarations.
Remove some default arguments from constructors.
sql/opt_sum.cc:
Use accessor functions in Item_sum.
sql/sql_select.cc:
Fix mis-spelled DBUG_ENTER text.
Use accessor functions in Item_sum.
sql/sql_yacc.yy:
Use explicit true/false rather than default arguments when constructing
Item_sum_xxx objects.
2630.39.1, 2630.28.29, 2630.34.3, 2630.34.2, 2630.34.1, 2630.29.29,
2630.29.28, 2630.31.1, 2630.28.13, 2630.28.10, 2617.23.14 and
some other minor revisions.
This patch implements:
WL#4264 "Backup: Stabilize Service Interface" -- all the
server prerequisites except si_objects.{h,cc} themselves (they can
be just copied over, when needed).
WL#4435: Support OUT-parameters in prepared statements.
(and all issues in the initial patches for these two
tasks, that were discovered in pushbuild and during testing).
Bug#39519: mysql_stmt_close() should flush all data
associated with the statement.
After execution of a prepared statement, send OUT parameters of the invoked
stored procedure, if any, to the client.
When using the binary protocol, send the parameters in an additional result
set over the wire. When using the text protocol, assign out parameters to
the user variables from the CALL(@var1, @var2, ...) specification.
The following refactoring has been made:
- Protocol::send_fields() was renamed to Protocol::send_result_set_metadata();
- A new Protocol::send_result_set_row() was introduced to incapsulate
common functionality for sending row data.
- Signature of Protocol::prepare_for_send() was changed: this operation
does not need a list of items, the number of items is fully sufficient.
The following backward incompatible changes have been made:
- CLIENT_MULTI_RESULTS is now enabled by default in the client;
- CLIENT_PS_MULTI_RESUTLS is now enabled by default in the client.
include/mysql.h:
Add a new flag to MYSQL_METHODS::flush_use_result
function pointer. This flag determines if all results
should be flushed or only the first one:
- if flush_all_results is TRUE, then cli_flush_use_result()
will read/flush all pending results. I.e. it will read
all packets while server status attribute indicates that
there are more results. This is a new semantic, required
to fix the bug.
- if flush_all_results is FALSE, the old sematic
is preserved -- i.e. cli_flush_use_result() reads data
until first EOF-packet.
include/mysql.h.pp:
Update the ABI with new calls (compatible changes).
include/mysql_com.h:
Add CLIENT_PS_OUT_PARAMS -- a client capability indicating that the client supportsю
libmysql/libmysql.c:
Add mysql_stmt_next_result() -- analogue of mysql_next_result() for binary protocol.
Fix a minor bug in alloc_fields() -- not all members were copied over,
and some only shallow-copied (catalog).
Flush all results in mysql_stmt_close() (Bug#39519).
libmysqld/lib_sql.cc:
Rename send_fields() -> send_result_set_metadata().
Refactoring: change prepare_for_send() so that it accepts only
what it really needs -- a number of elements in the list.
mysql-test/r/ps.result:
Update results: WL#4435.
mysql-test/t/ps.test:
WL#4435: A test case for an SQL-part of the problem.
sql-common/client.c:
Bug#39519.
Implement new functionality in cli_flush_use_result():
if flush_all_delete is TRUE, then it should read/flush
all pending results.
sql/Makefile.am:
Add a new header sql_prepare.h to the list
of build headers.
sql/events.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/handler.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/mysql_priv.h:
Move sql_prepare.cc-specific declarations to a new
header - sql_prepare.h.
sql/procedure.h:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/protocol.cc:
Move the logic responsible for sending of one result
set row to the Protocol class. Define a template
for end-of-statement action.
Refactoring: change prepare_for_send() so that it accepts
only what it really needs -- a number of elements in the list.
Rename send_fields() to send_result_set_metadata().
sql/protocol.h:
Update with new declarations (WL#4435).
Rename send_fields() -> send_result_set_metadata().
prepare_for_send() only needs the number of columns to send,
and doesn't use the item list - update signature to require
only what's needed.
Add a new protocol type -- Protocol_local.
sql/repl_failsafe.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/slave.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_acl.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_base.cc:
Include sql_prepare.h (for Reprepare_observer).
sql/sql_cache.cc:
Extend the query cache flags block to be able
to store a numeric id for the result format,
not just a flag binary/non-binary.
sql/sql_class.cc:
Update to use the rename of Protocol::send_fields()
to Protocol::send_result_set_metadata().
Use Protocol::send_one_result_set_row().
sql/sql_class.h:
Move the declaration of Reprepare_observer to the
new header - sql_prepare.h.
Update to the new signature of class Protocol::send_fields().
sql/sql_connect.cc:
Use a protocol template method instead of
raw NET layer API at the end of a statement.
sql/sql_cursor.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_error.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_handler.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
Use new method Protocol::send_one_result_set_row().
sql/sql_help.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_lex.cc:
Initialize multi_statements variable.
Add a handy constant for empty lex
string.
sql/sql_lex.h:
Add a separate member for a standalone
parsing option - multi-statements support.
sql/sql_list.cc:
sql_list.h is a standalone header now,
no need to include mysql_priv.h.
sql/sql_list.h:
Make sql_list.h a stand-alone header.
sql/sql_parse.cc:
Include sql_prepare.h for prepared
statements- related declarations.
Use a new Protocol template method to end
each statement (send OK, EOF or ERROR to
the client).
sql/sql_prepare.cc:
Implement Execute Direct API (WL#4264),
currently unused. It will be used by the service
interface (Backup).
Use a new header - sql_prepare.h.
Add support for OUT parameters in the
binary and text protocol (prepared statements
only).
sql/sql_prepare.h:
Add a new header to contain (for now)
all prepared statement- external
related declarations.
sql/sql_profile.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_repl.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_select.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_show.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_string.h:
Add a way to convert a String to LEX_STRING.
sql/sql_table.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_update.cc:
Remove an extraneous my_error(). The error
is already reported in update_non_unique_table_error().
sql/sql_yacc.yy:
Support for multi-statements is an independent
property of parsing, not derived from
the protocol type.
tests/mysql_client_test.c:
Add tests for WL#4435 (binary protocol).
line 138 when forcing a spatial index
Problem: "Spatial indexes can be involved in the search
for queries that use a function such as MBRContains()
or MBRWithin() in the WHERE clause".
Using spatial indexes for JOINs with =, <=> etc.
predicates is incorrect.
Fix: disable spatial indexes for such queries.
mysql-test/r/select.result:
Fix for bug#47019: Assertion failed: 0, file .\rt_mbr.c,
line 138 when forcing a spatial index
- test result.
mysql-test/t/select.test:
Fix for bug#47019: Assertion failed: 0, file .\rt_mbr.c,
line 138 when forcing a spatial index
- test case.
sql/sql_select.cc:
Fix for bug#47019: Assertion failed: 0, file .\rt_mbr.c,
line 138 when forcing a spatial index
- disable spatial indexes for queries which use
non-spatial conditions (e.g. NATURAL JOINs).
BUG#38049 "incorrect rows estimations with references from preceding table"
(from revid:sergefp@mysql.com-20090126194259-ue20il3qro529l4d).
Compared to 6.0 where EXPLAIN indicates "Using index condition", here in join_optimizer.result
we see "Using where"; it's normal; 6.0 shows the same if disabling Index Condition Pushdown.
EXPLAIN EXTENDED warning.
Query optimizer searches for the constant tables and optimizes them away. This
means that fields of such tables are substituted for their values and on later
phases they are treated as constants. After this constant tables are removed
from the query execution plan. Nevertheless constant tables were shown in
the EXPLAIN EXTENDED warning thus producing query that might be not an
equivalent of the original query.
Now the print_join function skips all tables that were optimized away from
printing to the EXPLAIN EXTENDED warning. If all tables were optimized away it
produces the 'FROM dual' clause.
mysql-test/r/explain.result:
A test case added for the bug#30302.
mysql-test/r/func_default.result:
Adjusted test case result after fix for the bug#30302.
mysql-test/r/func_regexp.result:
Adjusted test case result after fix for the bug#30302.
mysql-test/r/func_test.result:
Adjusted test case result after fix for the bug#30302.
mysql-test/r/having.result:
Adjusted test case result after fix for the bug#30302.
mysql-test/r/select.result:
Adjusted test case result after fix for the bug#30302.
mysql-test/r/subselect.result:
Adjusted test case result after fix for the bug#30302.
mysql-test/r/subselect3.result:
Adjusted test case result after fix for the bug#30302.
mysql-test/r/type_datetime.result:
Adjusted test case result after fix for the bug#30302.
mysql-test/t/explain.test:
A test case added for the bug#30302.
sql/sql_select.cc:
Bug#30302: Tables that were optimized away are printed in the
EXPLAIN EXTENDED warning.
Now the print_join function skips all tables that were optimized away from
printing to the EXPLAIN EXTENDED warning. If all tables were optimized away it
produces the 'FROM dual' clause.
sql/table.h:
Adjusted test case result after fix for the bug#30302.
The optimized_away flag is added to the TABLE_LIST struct.
----------------------------------------------------------
revno: 2630.22.11
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-records
timestamp: Mon 2008-08-11 16:40:09 +0400
message:
Move read_record related functions to a new header - records.h
sql/Makefile.am:
Introduce records.h
sql/handler.h:
Forward-declare class handler (an unnecessary forward declaration
was removed from mysql_priv.h).
sql/item_subselect.cc:
Make read_record function naming more consistent.
Assign read_record function at once, no need to defer till
read_first_record invocation.
sql/mysql_priv.h:
Include records.h, previously part of structs.h
sql/records.cc:
Use records.h
sql/sql_select.h:
Update to use new declarations.
sql/structs.h:
Move declarations of READ_RECORD and related functions to records.h
----------------------------------------------------------
revno: 2630.13.6
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-3288
timestamp: Fri 2008-07-11 20:22:44 +0400
message:
WL#3288, step 1: ensure that the SQL layer always closes an open
cursor (rnd or index read) before closing a handler.
sql/handler.h:
Assert that the read is closed in handler destructor.
sql/sql_select.cc:
Remove JOIN::table which was a piece of redundancy. The problem was
that JOIN::cleanup() works only if JOIN::table is not null,
but JOIN::cleanup also assigns JOIN::table to NULL. This assignment
is apparently there for safety, from the times when we had no support for correlated
subqueries. Indeed, in case of a evaluation of a correlated subquery more than once it led
to JOIN::cleanup doing nothing, and leaving the rnd or index read open.
In do_select(), make sure we call JOIN::join_free() even in case of an
error.
sql/sql_select.h:
Remove JOIN::table, JOIN::all_tables has the same functionality.
Temporary tables may set join->group to 0 even though there is
grouping. Also need to test if sum_func_count>0 when JOIN::exec()
decides whether to present results in a grouped manner.
sql/sql_select.cc:
Temporary tables may set join->group to 0 even though there is
grouping. Also need to test if sum_func_count>0 when JOIN::exec()
decides whether to present results in a grouped manner.
columns without where/group
Simple SELECT with implicit grouping used to return many rows if
the query was ordered by the aggregated column in the SELECT
list. This was incorrect because queries with implicit grouping
should only return a single record.
The problem was that when JOIN:exec() decided if execution needed
to handle grouping, it was assumed that sum_func_count==0 meant
that there were no aggregate functions in the query. This
assumption was not correct in JOIN::exec() because the aggregate
functions might have been optimized away during JOIN::optimize().
The reason why queries without ordering behaved correctly was
that sum_func_count is only recalculated if the optimizer chooses
to use temporary tables (which it does in the ordered case).
Hence, non-ordered queries were correctly treated as grouped.
The fix for this bug was to remove the assumption that
sum_func_count==0 means that there is no need for grouping. This
was done by introducing variable "bool implicit_grouping" in the
JOIN object.
mysql-test/r/func_group.result:
Add test for BUG#47280
mysql-test/t/func_group.test:
Add test for BUG#47280
sql/opt_sum.cc:
Improve comment for opt_sum_query()
sql/sql_class.h:
Add comment for variables in TMP_TABLE_PARAM
sql/sql_select.cc:
Introduce and use variable implicit_grouping instead of (!group_list && sum_func_count) in places that need to test if grouping is required. Also added comments for: optimization of aggregate fields for implicitly grouped queries (JOIN::optimize) and choice of end_select method (JOIN::execute)
sql/sql_select.h:
Add variable implicit_grouping, which will be TRUE for queries that contain aggregate functions but no GROUP BY clause. Also added comment to sort_and_group variable.
local storage for query cache).
We need more than one pointer in a thread to
represent the query cache and net->query_cache_query can not be used
any more (due to ABI compatibility issues and to different life
time of NET and THD).
This is a backport of the following patch from 6.0:
----------------------------------------------------------
revno: 2476.1157.2
committer: kostja@bodhi.(none)
timestamp: Sat 2007-06-16 13:29:24 +0400
include/mysql.h.pp:
Update the ABI (NET::query_cache_query is now unused).
include/mysql_com.h:
NET::query_cache_query is now unused.
sql/mysql_priv.h:
Update signatures of ex-functios now member functions.
sql/sql_cache.cc:
Introduce THD::query_cache_tls.
sql/sql_cache.h:
Introduce THD::query_cache_tls.
sql/sql_class.cc:
Introduce THD::query_cache_tls.
sql/sql_class.h:
Introduce THD::query_cache_tls.
sql/sql_parse.cc:
Use THD::query_cache_tls.
sql/sql_select.cc:
Use THD::query_cache_tls.
buffering is used
FORCE INDEX FOR ORDER BY now prevents the optimizer from
using join buffering. As a result the optimizer can use
indexed access on the first table and doesn't need to
sort the complete resultset at the end of the statement.
the fix is reverted from 5.1, mysql-pe as
unnecessary(no valgrind warnings there).
sql/sql_select.cc:
the fix is reverted from 5.1, mysql-pe as
unnecessary(no valgrind warnings there).
query
The fix for bug 46749 removed the check for OUTER_REF_TABLE_BIT
and substituted it for a check on the presence of
Item_ident::depended_from.
Removing it altogether was wrong : OUTER_REF_TABLE_BIT should
still be checked in addition to depended_from (because it's not
set in all cases and doesn't contradict to the check of depended_from).
Fixed by returning the old condition back as a compliment to the
new one.
