Bug#33031 app linked to libmysql.lib crash if run as service in vista under
localsystem
There are some problems using DllMain hook functions on Windows that
automatically do global and per-thread initialization for libmysqld.dll
1)per-thread initialization(DLL_THREAD_ATTACH)
MySQL internally counts number of active threads that and causes a delay in in
my_end() if not all threads are exited. But,there are threads that can be
started either by Windows internally (often in TCP/IP scenarios) or by user
himself - those threads are not necessarily using libmysql.dll functionality,
but nonetheless the contribute to the count of open threads.
2)process-initialization (DLL_PROCESS_ATTACH)
my_init() calls WSAStartup that itself loads DLLs and can lead to a deadlock in
Windows loader.
Fix is to remove dll initialization code from libmysql.dll in general case. I
still leave an environment variable LIBMYSQL_DLLINIT, which if set to any value
will cause the old behavior (DLL init hooks will be called). This env.variable
exists only to prevent breakage of existing Windows-only applications that
don't do mysql_thread_init() and work ok today. Use of LIBMYSQL_DLLINIT is
discouraged and it will be removed in 6.0
Bug#33031 app linked to libmysql.lib crash if run as service in vista under
localsystem
There are some problems using DllMain hook functions on Windows that
automatically do global and per-thread initialization for libmysqld.dll
1)per-thread initialization(DLL_THREAD_ATTACH)
MySQL internally counts number of active threads that and causes a delay in in
my_end() if not all threads are exited. But,there are threads that can be
started either by Windows internally (often in TCP/IP scenarios) or by user
himself - those threads are not necessarily using libmysql.dll functionality,
but nonetheless the contribute to the count of open threads.
2)process-initialization (DLL_PROCESS_ATTACH)
my_init() calls WSAStartup that itself loads DLLs and can lead to a deadlock in
Windows loader.
Fix is to remove dll initialization code from libmysql.dll in general case. I
still leave an environment variable LIBMYSQL_DLLINIT, which if set to any value
will cause the old behavior (DLL init hooks will be called). This env.variable
exists only to prevent breakage of existing Windows-only applications that
don't do mysql_thread_init() and work ok today. Use of LIBMYSQL_DLLINIT is
discouraged and it will be removed in 6.0
The assert is about binlogging must have been activated, but it was
not actually according to the reported how-to-repeat instuctions.
Analysis revealed that binlog_start_trans_and_stmt() was called
without prior testing if binlogging is ON.
Fixed with avoing entering binlog_start_trans_and_stmt() if binlog is
not activated.
post push patch
when building with valgrind, it does not compile in realpath,
so this test fails when using a valgrind build
NOTE: building with valgrind is not the same as useing the
--valgrind option with mysql-test-run
returns unexpected result
If:
1. a table has a not nullable BIT column c1 with a length
shorter than 8 bits and some additional not nullable
columns c2 etc, and
2. the WHERE clause is like: (c1 = constant) AND c2 ...,
the SELECT query returns unexpected result set.
The server stores BIT columns in a tricky way to save disk
space: if column's bit length is not divisible by 8, the
server places reminder bits among the null bits at the start
of a record. The rest bytes are stored in the record itself,
and Field::ptr points to these rest bytes.
However if a bit length of the whole column is less than 8,
there are no remaining bytes, and there is nothing to store in
the record at its regular place. In this case Field::ptr points
to bytes actually occupied by the next column in a record.
If both columns (BIT and the next column) are NOT NULL,
the Field::eq function incorrectly deduces that this is the
same column, so query transformation/equal item elimination
code (see build_equal_items_for_cond) may mix these columns
and damage conditions containing references to them.
used causes server crash.
When the loose index scan access method is used values of aggregated functions
are precomputed by it. Aggregation of such functions shouldn't be performed
in this case and functions should be treated as normal ones.
The create_tmp_table function wasn't taking this into account and this led to
a crash if a query has MIN/MAX aggregate functions and employs temporary table
and loose index scan.
Now the JOIN::exec and the create_tmp_table functions treat MIN/MAX aggregate
functions as normal ones when the loose index scan is used.
tables open
When executing a DROP DATABASE statement in ROW mode and having temporary
tables open at the same time, the existance of temporary tables prevent
the server from switching back to row mode after temporarily switching to
statement mode to handle the logging of the statement.
Fixed the problem by removing the code to switch to statement mode and added
code to temporarily disable the binary log while dropping the objects in the
database.
Problem: data consistency check (maximum record length) for a correct
MyISAM table with CHECKSUM=1 and ROW_FORMAT=DYNAMIC option
may fail due to wrong inner MyISAM parameter. In result we may
have the table marked as 'corrupted'.
Fix: properly set MyISAM maximum record length parameter.
