Item*) at opt_sum.cc:305
Queries applying MIN/MAX functions to indexed columns are
optimized to read directly from the index if all key parts
of the index preceding the aggregated key part are bound to
constants by the WHERE clause. A prefix length is also
produced, equal to the total length of the bound key
parts. If the aggregated column itself is bound to a
constant, however, it is also included in the prefix.
Such full search keys are read as closed intervals for
reasons beyond the scope of this bug. However, the procedure
missed one case where a key part meant for use as range
endpoint was being overwritten with a NULL value destined
for equality checking. In this case the key part was
overwritten but the range flag remained, causing open
interval reading to be performed.
Bug was fixed by adding more stringent checking to the
search key building procedure (matching_cond) and never
allow overwrites of range predicates with non-range
predicates.
An assertion was added to make sure open intervals are never
used with full search keys.
strict aliasing violations.
One somewhat major source of strict-aliasing violations and
related warnings is the SQL_LIST structure. For example,
consider its member function `link_in_list` which takes
a pointer to pointer of type T (any type) as a pointer to
pointer to unsigned char. Dereferencing this pointer, which
is done to reset the next field, violates strict-aliasing
rules and might cause problems for surrounding code that
uses the next field of the object being added to the list.
The solution is to use templates to parametrize the SQL_LIST
structure in order to deference the pointers with compatible
types. As a side bonus, it becomes possible to remove quite
a few casts related to acessing data members of SQL_LIST.
sql/handler.h:
Use the appropriate template type argument.
sql/item.cc:
Remove now-unnecessary cast.
sql/item_subselect.cc:
Remove now-unnecessary casts.
sql/item_sum.cc:
Use the appropriate template type argument.
Remove now-unnecessary cast.
sql/mysql_priv.h:
Move SQL_LIST structure to sql_list.h
Use the appropriate template type argument.
sql/sp.cc:
Remove now-unnecessary casts.
sql/sql_delete.cc:
Use the appropriate template type argument.
Remove now-unnecessary casts.
sql/sql_derived.cc:
Remove now-unnecessary casts.
sql/sql_lex.cc:
Remove now-unnecessary casts.
sql/sql_lex.h:
SQL_LIST now takes a template type argument which must
match the type of the elements of the list. Use forward
declaration when the type is not available, it is used
in pointers anyway.
sql/sql_list.h:
Rename SQL_LIST to SQL_I_List. The template parameter is
the type of object that is stored in the list.
sql/sql_olap.cc:
Remove now-unnecessary casts.
sql/sql_parse.cc:
Remove now-unnecessary casts.
sql/sql_prepare.cc:
Remove now-unnecessary casts.
sql/sql_select.cc:
Remove now-unnecessary casts.
sql/sql_show.cc:
Remove now-unnecessary casts.
sql/sql_table.cc:
Remove now-unnecessary casts.
sql/sql_trigger.cc:
Remove now-unnecessary casts.
sql/sql_union.cc:
Remove now-unnecessary casts.
sql/sql_update.cc:
Remove now-unnecessary casts.
sql/sql_view.cc:
Remove now-unnecessary casts.
sql/sql_yacc.yy:
Remove now-unnecessary casts.
storage/myisammrg/ha_myisammrg.cc:
Remove now-unnecessary casts.
strict aliasing violations.
Essentially, the problem is that large parts of the server were
developed in simpler times (last decades, pre C99 standard) when
strict aliasing and compilers supporting such optimizations were
rare to non-existent. Thus, when compiling the server with a modern
compiler that uses strict aliasing rules to perform optimizations,
there are several places in the code that might trigger undefined
behavior.
As evinced by some recent bugs, GCC does a somewhat good of job
misoptimizing such code, but on the other hand also gives warnings
about suspicious code. One problem is that the warnings aren't
always accurate, yet we can't afford to just shut them off as we
might miss real cases. False-positive cases are aggravated mostly
by casts that are likely to trigger undefined behavior.
The solution is to start a cleanup process focused on fixing and
reducing the amount of strict-aliasing related warnings produced
by GCC and others compilers. A good deal of noise reduction can
be achieved by just removing useless casts that are product of
historical cruft and are likely to trigger undefined behavior if
dereferenced.
client/mysql.cc:
Remove now-unnecessary casts.
Break up large strings.
client/mysql_upgrade.c:
Remove now-unnecessary casts.
client/mysqladmin.cc:
Remove now-unnecessary casts.
Break up large strings.
client/mysqlbinlog.cc:
Remove now-unnecessary casts.
client/mysqlcheck.c:
Remove now-unnecessary casts.
client/mysqldump.c:
Remove now-unnecessary casts.
client/mysqlimport.c:
Remove now-unnecessary casts.
client/mysqlshow.c:
Remove now-unnecessary casts.
client/mysqlslap.c:
Remove now-unnecessary casts.
client/mysqltest.cc:
Remove now-unnecessary casts.
extra/comp_err.c:
Remove now-unnecessary casts.
extra/my_print_defaults.c:
Remove now-unnecessary casts.
Break up large strings.
extra/mysql_waitpid.c:
Remove now-unnecessary casts.
extra/perror.c:
Remove now-unnecessary casts.
extra/resolve_stack_dump.c:
Remove now-unnecessary casts.
extra/resolveip.c:
Remove now-unnecessary casts.
include/my_getopt.h:
Use a void pointer type as the opaque type to avoid problems with type
incompatibility -- GCC issues warnings when the type name is not type
compatible with a operand. As a side bonus, a explicit cast won't be
necessary anymore.
include/sslopt-longopts.h:
Remove now-unnecessary casts.
Break up large strings.
mysys/my_getopt.c:
Update opaque type and introduce a type definition for the
argument to my_getopt_register_get_addr.
server-tools/instance-manager/options.cc:
Remove now-unnecessary casts.
sql/mysqld.cc:
Remove now-unnecessary casts.
Break up large strings.
Update mysql_getopt_value prototype (the old prototype
was different from the definition anyway).
sql/sql_plugin.cc:
The type of a pointer to a function must be compatible with the
pointed-to function type, otherwise the behavior is undefined.
sql/table.cc:
The variable buf pointer to pointer to pointer to constant char
could improperly alias a incompatible type in call to fix_type_
pointers. Since this was actually dead code, it is simply removed.
sql/unireg.cc:
Remove call to get_form_pos. The code creates a new FRM file which
is always truncated and writes the form position as 0. Hence, no
need to retrieve it, we now for sure it is 0.
storage/archive/archive_reader.c:
Remove now-unnecessary casts.
storage/myisam/ft_nlq_search.c:
Read weight directly from the buffer.
storage/myisam/fulltext.h:
Add explanation about the type duality of a key buffer.
Add accessor macro to retrieve a FT float value.
storage/myisam/mi_test1.c:
Remove now-unnecessary casts.
storage/myisam/myisam_ftdump.c:
Read weight directly from the buffer.
storage/myisam/myisamchk.c:
Remove now-unnecessary casts.
storage/myisam/myisamlog.c:
A pointer to char was used to alias a pointer to pointer to
unsigned char, thus violating strict aliasing rules.
storage/myisam/myisampack.c:
Remove now-unnecessary casts.
strings/decimal.c:
Remove aliasing violation, printing the value is enough for
debugging purposes.
tests/mysql_client_test.c:
Remove now-unnecessary casts.
The bug was caused by buffered output. Flushing resolved it.
We still recommend to allways call plan().
Also fix some compile warnings (formal parameter different from declaration)
unittest/examples/Makefile.am:
Omit core-t, since it will always fail.
unittest/examples/no_plan-t.c:
Comment that we recommend calling plan(NO_PLAN)
unittest/mytap/tap.c:
Use the named constant NO_PLAN
Flush all output.
unittest/mytap/tap.h:
Change documentation for the plan() function.
Addendum: Work around a compilation failure on Windows due to
windows.h not being added to the global namespace.
extra/yassl/include/lock.hpp:
Move windows.h inclusion into the global namespace.
(InnoDB plugin branch)
mysql-test/suite/innodb_plugin/r/innodb_mysql.result:
test case
mysql-test/suite/innodb_plugin/t/innodb_mysql.test:
test case
storage/innodb_plugin/row/row0sel.c:
init null bytes with default values as they might be
left uninitialized in some cases and these uninited bytes
might be copied into mysql record buffer that leads to
valgrind warnings on next use of the buffer.
Valgrind warning happpens because of uninitialized null bytes.
In row_sel_push_cache_row_for_mysql() function we fill fetch cache
with necessary field values, row_sel_store_mysql_rec() is called
for this and leaves null bytes untouched.
Later row_sel_pop_cached_row_for_mysql() rewrites table record
buffer with uninited null bytes. We can see the problem from the
test case:
At 'SELECT...' we call row_sel_push...->row_sel_store...->row_sel_pop_cached...
chain which rewrites table->record[0] buffer with uninitialized null bytes.
When we call 'UPDATE...' statement, compare_record uses this buffer and
valgrind warning occurs.
The fix is to init null bytes with default values.
mysql-test/suite/innodb/r/innodb_mysql.result:
test case
mysql-test/suite/innodb/t/innodb_mysql.test:
test case
mysql-test/t/ps_3innodb.test:
enable valgrind testing
storage/innobase/row/row0sel.c:
init null bytes with default values as they might be
left uninitialized in some cases and these uninited bytes
might be copied into mysql record buffer that leads to
valgrind warnings on next use of the buffer.
Problem: the server missed the fact that one can read from
2 indexes alternately using HANDLER interface.
Fix: check if the same (initialized) index is involved
reading next/prev values from the index.
mysql-test/r/handler_myisam.result:
Fix for bug #54007: assert in ha_myisam::index_next, HANDLER
- test result.
mysql-test/t/handler_myisam.test:
Fix for bug #54007: assert in ha_myisam::index_next, HANDLER
- test case.
sql/sql_handler.cc:
Fix for bug #54007: assert in ha_myisam::index_next, HANDLER
- check if we use the same (initialized) index
to read next/prev values from the index.
Added option --user-args, to be used with --start*
Only keeps --defaults-file and --defaults-group-suffix
Also added missing help text entry for --start-and-exit
config/ac-macros/ssl.m4:
Enable yaSSL thread safety if linking with the server or a
thread safe client library. Avoids building a thread safe
yaSSL when only building a non-thread safe client library.
The problem was that the bundled yaSSL library was being built
without thread safety support regardless of the thread safeness
of the compoments linked with it.
The solution is to enable yaSSL thread safety support if any
component (server or client) is to be built with thread support.
Also, generate new certificates for yaSSL's test suite.
config/ac-macros/yassl.m4:
Enable yaSSL thread safety if linking with the server or a
thread safe client library. Avoids building a thread safe
yaSSL when only building a non-thread safe client library.
extra/yassl/CMakeLists.txt:
Always enable for Windows builds.
extra/yassl/certs/ca-cert.pem:
New certificate, previous one expired.
extra/yassl/certs/client-cert.der:
New certificate, previous one expired.
extra/yassl/certs/client-cert.pem:
New certificate, previous one expired.
extra/yassl/certs/dsa-cert.pem:
New certificate, previous one expired.
extra/yassl/certs/server-cert.pem:
New certificate, previous one expired.
extra/yassl/include/lock.hpp:
Rename MULTI_THREAD to YASSL_THREAD_SAFE.
extra/yassl/src/Makefile.am:
Use CXXFLAGS to set thread related definitions as the lock header
(lock.hpp) has no local dependencies.
extra/yassl/src/lock.cpp:
Rename MULTI_THREAD to YASSL_THREAD_SAFE.
extra/yassl/taocrypt/CMakeLists.txt:
Always enable for Windows builds.
extra/yassl/taocrypt/benchmark/Makefile.am:
Pass thread related CXXFLAGS.
extra/yassl/taocrypt/src/Makefile.am:
Pass thread related CXXFLAGS.
extra/yassl/taocrypt/test/Makefile.am:
Pass thread related CXXFLAGS.
extra/yassl/taocrypt/test/memory.cpp:
Rename MULTI_THREAD to YASSL_THREAD_SAFE.
extra/yassl/testsuite/Makefile.am:
Pass thread related CXXFLAGS.
for InnoDB plugin
dict_load_table(): Pass the correct tablespace flags to
fil_open_single_table_tablespace(). For ROW_FORMAT=COMPACT and REDUNDANT,
the tablespace flags are 0. The table flags would be 0 or DICT_TF_COMPACT.
Logging slow stored procedures caused the slow log to write
very large lock times. The lock times was a result of a
negative number being cast to an unsigned integer.
The reason the lock time appeard negative was because
one of the measurements points was reset after execution
causing it to change order with the start time of the
statement.
This bug is related to bug 47905 which in turn was
introduced because of a joint fix for 12480,12481,12482 and 11587.
The fix is to only reset the start_time before any statement
execution in a SP while not resetting start_utime or
utime_after_lock which are used for measuring the
performance of the SP. Start_time is used to set the
timestamp on the replication event which controlls how
the slave interprets time functions like NOW().
The problem is in the Item_func_isnull::update_used_tables() function,
bracket is at the wrong place. Because of that isnull item erroneously
is treated as const item. The fix is to set brackets in the right place.
mysql-test/r/func_isnull.result:
test case
mysql-test/t/func_isnull.test:
test case
sql/item_cmpfunc.h:
set brackets in the right place.
NET::skip_big_packet isn't defined for the embedded server,
hide it in such a case.
sql/sql_connect.cc:
Fix for bug #53912: Fails to build from source
- hide net.skip_big_packet for the embedded server,
as it isn't defined there.
Some of the server implementations don't support dates later
than 2038 due to the internal time type being 32 bit.
Added checks so that the server will refuse dates that cannot
be handled by either throwing an error when setting date at
runtime or by refusing to start or shutting down the server if
the system date cannot be stored in my_time_t.
Post-push fix.
There was a valgrind issue on the loop that checks whether there
are NULL fields in the UNIQUE KEY or not. In detail, for the last
iteration the server may read out of the key_part array boundaries,
making valgrind to output warnings.
We fix this by correcting the loop, ie, moving the part that reads
from the key_part to be inside the loop statement block. This way
the assignment is protected by the loop condition.
