Fix warnings flagged by the new warning option -Wunused-but-set-variable
that was added to GCC 4.6 and that is enabled by -Wunused and -Wall. The
option causes a warning whenever a local variable is assigned to but is
later unused. It also warns about meaningless pointer dereferences.
client/mysql.cc:
Meaningless pointer dereferences.
client/mysql_upgrade.c:
Check whether reading from the file succeeded.
extra/comp_err.c:
Unused.
extra/yassl/src/yassl_imp.cpp:
Skip instead of reading data that is discarded.
include/my_pthread.h:
Variable is only used in debug builds.
include/mysys_err.h:
Add new error messages.
mysys/errors.c:
Add new error message for permission related functions.
mysys/mf_iocache.c:
Variable is only checked under THREAD.
mysys/my_copy.c:
Raise a error if chmod or chown fails.
mysys/my_redel.c:
Raise a error if chmod or chown fails.
regex/engine.c:
Use a equivalent variable for the assert.
server-tools/instance-manager/instance_options.cc:
Unused.
sql/field.cc:
Unused.
sql/item.cc:
Unused.
sql/log.cc:
Do not ignore the return value of freopen: only set buffer if
reopening succeeds.
Adjust doxygen comment to the right function.
Pass message lenght to log function.
sql/mysqld.cc:
Do not ignore the return value of freopen: only set buffer if
reopening succeeds.
sql/partition_info.cc:
Unused.
sql/slave.cc:
No need to set pointer to the address of '\0'.
sql/spatial.cc:
Unused. Left for historical purposes.
sql/sql_acl.cc:
Unused.
sql/sql_base.cc:
Pointers are always set to the same variables.
sql/sql_parse.cc:
End statement if reading fails.
Store the buffer after it has actually been updated.
sql/sql_repl.cc:
No need to set pointer to the address of '\0'.
sql/sql_show.cc:
Put variable under the same ifdef block.
sql/udf_example.c:
Set null pointer flag appropriately.
storage/csv/ha_tina.cc:
Meaningless dereferences.
storage/example/ha_example.cc:
Return the error since it's available.
storage/myisam/mi_locking.c:
Remove unused and dead code.
due to GCC preprocessor change
The problem is that newer GCC versions treats missing headers
as fatal errors. The solution is to use a guard macro to prevent
the inclusion of system headers when checking the ABI with the
C Preprocessor.
Reference: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15638http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44836
Makefile.am:
Define guard macro.
configure.in:
Remove workaround.
include/mysql.h:
Guard the header inclusion.
include/mysql.h.pp:
Header is not included anymore.
table with active trx
Essentially, the problem is that InnoDB does a implicit commit
when a cursor (table handler) is unlocked/closed, creating
a dissonance between the transaction state within the server
layer and the storage engine layer. Theoretically, a statement
transaction can encompass several table instances in a similar
manner to a multiple statement transaction, hence it does not
make sense to limit a statement transaction to the lifetime of
the table instances (cursors) used within it.
Since this particular instance of the problem is only triggerable
on 5.1 and is masked on 5.5 due 2PC being skipped (assertion is in
the prepare phase of a 2PC), the solution (which is less risky) is
to explicitly end the transaction before the cached table is unlock
on rename table.
The patch is to be null merged into trunk.
mysql-test/include/commit.inc:
Fix counters, the binlog engine does not get involved anymore.
mysql-test/suite/innodb_plugin/r/innodb_bug54453.result:
Add test case result for Bug#54453
mysql-test/suite/innodb_plugin/t/innodb_bug54453.test:
Add test case for Bug#54453
sql/sql_table.cc:
End transaction as otherwise InnoDB will end it behind our backs.
Problem: when SHOW BINLOG EVENTS was issued, it increased the value of
@@session.max_allowed_packet. This allowed a non-root user to increase
the amount of memory used by her thread arbitrarily. Thus, it removes
the bound on the amount of system resources used by a client, so it
presents a security risk (DoS attack).
Fix: it is correct to increase the value of @@session.max_allowed_packet
while executing SHOW BINLOG EVENTS (see BUG 30435). However, the
increase should only be temporary. Thus, the fix is to restore the value
when SHOW BINLOG EVENTS ends.
The value of @@session.max_allowed_packet is also increased in
mysql_binlog_send (i.e., the binlog dump thread). It is not clear if this
can cause any trouble, since normally the client that issues
COM_BINLOG_DUMP will not issue any other commands that would be affected
by the increased value of @@session.max_allowed_packet. However, we
restore the value just in case.
mysql-test/suite/rpl/r/rpl_packet.result:
update result file
mysql-test/suite/rpl/t/rpl_packet.test:
Add test that verifies that @@session.max_allowed_packet does not change
when issuing SHOW BINLOG EVENTS.
Make previous sub-test clean up.
Add comments listing the bugs in this test case.
sql/sql_repl.cc:
Restore the old value of thd->variables.max_allowed_packet at the
end of mysql_binlog_send and mysql_show_binlog_events.
Bug#52261: 64 bit atomic operations do not work on Solaris i386
gcc in debug compilation
One of the various problems was that the source operand to
CMPXCHG8b was marked as a input/output operand, causing GCC
to use the EBX register as the destination register for the
CMPXCHG8b instruction. This could lead to crashes as the EBX
register is also implicitly used by the instruction, causing
the value to be potentially garbaged and a protection fault
once the value is used to access a position in memory.
Another problem was the lack of proper clobbers for the atomic
operations and, also, a discrepancy between the implementations
for the Compare and Set operation. The specific problems are
described and fixed by Kristian Nielsen patches:
Patch: 1
Fix bugs in my_atomic_cas*(val,cmp,new) that *cmp is accessed
after CAS succeds.
In the gcc builtin implementation, problem was that *cmp was
read again after atomic CAS to check if old *val == *cmp;
this fails if CAS is successful and another thread modifies
*cmp in-between.
In the x86-gcc implementation, problem was that *cmp was set
also in the case of successful CAS; this means there is a
window where it can clobber a value written by another thread
after successful CAS.
Patch 2:
Add a GCC asm "memory" clobber to primitives that imply a
memory barrier.
This signifies to GCC that any potentially aliased memory
must be flushed before the operation, and re-read after the
operation, so that read or modification in other threads of
such memory values will work as intended.
In effect, it makes these primitives work as memory barriers
for the compiler as well as the CPU. This is better and more
correct than adding "volatile" to variables.
include/atomic/gcc_builtins.h:
Do not read from *cmp after the operation as it might be
already gone if the operation was successful.
include/atomic/nolock.h:
Prefer system provided atomics over the broken x86 asm.
include/atomic/x86-gcc.h:
Do not mark source operands as input/output operands.
Add proper memory clobbers.
include/my_atomic.h:
Add notes about my_atomic_add and my_atomic_cas behaviors.
unittest/mysys/my_atomic-t.c:
Remove work around, if it fails, there is either a problem
with the atomic operations code or the specific compiler
version should be black-listed.
This bug is a design flaw of the fix for the bug#33546. It assumed that an
item can be used only in one comparison context, but actually it isn't the
case. Item_cache_datetime is used to store result for MIX/MAX aggregate
functions. Because Arg_comparator always compares datetime values as INTs when
possible the Item_cache_datetime most time caches only INT value. But
since all datetime values has STRING result type MIN/MAX functions are asked
for a STRING value when the result is being sent to a client. The
Item_cache_datetime was designed to avoid conversions and get INT/STRING
values from an underlying item, but at the moment the values is asked
underlying item doesn't hold it anymore thus wrong result is returned.
Beside that MIN/MAX aggregate functions was wrongly initializing cached result
and this led to a wrong result.
The Item::has_compatible_context helper function is added. It checks whether
this and given items has the same comparison context or can be compared as
DATETIME values by Arg_comparator. The equality propagation optimization is
adjusted to take into account that items which being compared as DATETIME
can have different comparison contexts.
The Item_cache_datetime now converts cached INT value to a correct STRING
DATETIME value by means of number_to_datetime & my_TIME_to_str functions.
The Arg_comparator::set_cmp_context_for_datetime helper function is added.
It sets comparison context of items being compared as DATETIMEs to INT if
items will be compared as longlong.
The Item_sum_hybrid::setup function now correctly initializes its result
value.
In order to avoid unnecessary conversions Item_sum_hybrid now states that it
can provide correct longlong value if the item being aggregated can do it
too.
mysql-test/r/group_by.result:
Added a test case for the bug#49771.
sql/item.cc:
Bug#49771: Incorrect MIN/MAX for date/time values.
The equality propagation mechanism is adjusted to take into account that
items which being compared as DATETIME can have different comparison
contexts.
The Item_cache_datetime now converts cached INT value to a correct STRING
DATETIME/TIME value.
sql/item.h:
Bug#49771: Incorrect MIN/MAX for date/time values.
The Item::has_compatible_context helper function is added. It checks whether
this and given items has the same comparison context or can be compared as
DATETIME values by Arg_comparator.
Added Item_cache::clear helper function.
sql/item_cmpfunc.cc:
Bug#49771: Incorrect MIN/MAX for date/time values.
The Arg_comparator::set_cmp_func now sets the correct comparison context
for items being compared as DATETIME values.
sql/item_cmpfunc.h:
Bug#49771: Incorrect MIN/MAX for date/time values.
The Arg_comparator::set_cmp_context_for_datetime helper function is added.
It sets comparison context of items being compared as DATETIMEs to INT if
items will be compared as longlong.
sql/item_sum.cc:
Bug#49771: Incorrect MIN/MAX for date/time values.
The Item_sum_hybrid::setup function now correctly initializes its result
value.
sql/item_sum.h:
Bug#49771: Incorrect MIN/MAX for date/time values.
In order to avoid unnecessary conversions Item_sum_hybrid now states that it
can provide correct longlong value if the item being aggregated can do it
too.
This assert checks that the server does not try to send OK to the
client if there has been some error during processing. This is done
to make sure that the error is in fact sent to the client.
The problem was that view errors during processing of WHERE conditions
in UPDATE statements where not detected by the update code. It therefore
tried to send OK to the client, triggering the assert.
The bug was only noticeable in debug builds.
This patch fixes the problem by making sure that the update code
checks for errors during condition processing and acts accordingly.
of the "embedded" server
Problem: mysqltest_embedded failed to load ha_innodb_plugin library
on some platforms (due to some unresolved references).
Fix: on FreeBSD use -export-dynamic flag building mysqltest_embedded.
That allows to use its global symbols to resolve references in the
dynamically loaded plugin library.
libmysqld/examples/Makefile.am:
Fix for bug #50667: The InnoDB plugin prevents initialization
of the "embedded" server
- use -export-dynamic (on FreeBSD/DragonFly) building
mysqltest_embedded to allow using its global symbols
to resolve references in the dynamically loaded plugin libraries.
