Addendum fixes after changing the condition variable
for the global read lock.
The stress test suite revealed some deadlocks. Some were
related to the new condition variable (COND_global_read_lock)
and some were general problems with the global read lock.
It is now necessary to signal COND_global_read_lock whenever
COND_refresh is signalled.
We need to wait for the release of a global read lock if one
is set before every operation that requires a write lock.
But we must not wait if we have locked tables by LOCK TABLES.
After setting a global read lock a thread waits until all
write locks are released.
Problem:
mysqld --collation-server=xxx --character-set-server=yyy
didn't work as expected: collation_server was set not to xxx,
but to the default collation of character set "yyy".
With different argument order it worked as expected:
mysqld --character-set-server=yyy --collation-server=yyy
Fix:
initializate default_collation_name to 0
when processing --character-set-server
only if --collation-server has not been specified
in command line.
The problem was a call to convert_dirname() with a destination buffer
that did not have room for the trailing slash added by that function.
This could cause the instance manager to crash in some cases.
An UNIQUE KEY consisting of NOT NULL columns
was displayed as PRIMARY KEY in "DESC t1".
According to the code, that was intentional
behaviour for some reasons unknown to me.
This code was written before bitkeeper time,
so I cannot check who and why made this.
After discussing on dev-public, a decision
was made to remove this code
This was another manifestation of the problems fixed in the
patch for bug 16674.
Wrong calculation of length of the search prefix in the pattern
string led here to a wrong result set for a query in 4.1.
The bug could be demonstrated for any multi-byte character set.
Server crashed in some cases when a query required a MIN/MAX
agrregation for a 'ucs2' field.
In these cases the aggregation caused calls of the function
update_tmptable_sum_func that indirectly invoked
the method Item_sum_hybrid::min_max_update_str_field()
containing a call to strip_sp for a ucs2 character set.
The latter led directly to the crash as it used my_isspace
undefined for the ucs2 character set.
Actually the call of strip_sp is not needed at all in this
situation and has been removed by the fix.
mysqldump.test calls my_print_defaults in a way that includes the systemwide
my.cnf, so the results will be beyond our control and depend on whatever the
user has in their my.cnf, namely the [mysqldump] section.
call my_print_defaults with --config-file rather than --defaults-extra-file
to prevent inclusion of system-wide defaults and use our config-file only.
- The setting of "ENV{'TZ'}" doesn't affect the timezone
used by MySQL Server on Windows.
- Explicitly set timezone in test cases before doing UTC/localtime
conversions so tests produce deterministic results
- The setting of "ENV{'TZ'}" doesn't affect the timezone
used by MySQL Server on Windows.
- Explicitly set timezone to "+03:00" in test case before
doing the calculatiosn to check that there is three hours
difference between utc and local time.
(Magnus' fix)
The AsBinary function returns VARCHAR data type with binary collation.
It can cause problem for clients that treat that kind of data as
different from BLOB type.
So now AsBinary returns BLOB.
with PREPARE fails with weird error".
More generally, re-executing a stored procedure with a complex SP cursor query
could lead to a crash.
The cause of the problem was that SP cursor queries were not optimized
properly at first execution: their parse tree belongs to sp_instr_cpush,
not sp_instr_copen, and thus the tree was tagged "EXECUTED" when the
cursor was declared, not when it was opened. This led to loss of optimization
transformations performed at first execution, as sp_instr_copen saw that the
query is already "EXECUTED" and therefore either not ran first-execution
related blocks or wrongly rolled back the transformations caused by
first-execution code.
The fix is to update the state of the parsed tree only when the tree is
executed, as opposed to when the instruction containing the tree is executed.
Assignment if i->state is moved to reset_lex_and_exec_core.
The problem was in redundant calls to strlen() in string functions,
where we may then return after checking only the small number of characters.
No test case is provided since it's a performance fix.
