The slave thread changed the format of the information it used to
connect to the master after patch for BUG 13963. This resulted
in old master getting confused, thence rejecting the slave
connection attempt.
In particular, patch for BUG 13963 removed the rpl_recovery_rank
variable which was, at that time, packed together with the rest
of the information which the slave would use to register itself
on the master. Based on this data, the master would then assert
that the number of bytes received in the connection command was
consistent to what it was expecting.
Therefore, given that a slave, patched with the aforementioned
patch, would not pack the four bytes related to the
rpl_recovery_rank variable, the old master would reject the
connection attempt. It would assume that the data was
inconsistent (fewer bytes than it was expecting) and return
an error.
We fix this by faking an rpl_recovery_rank variable when
registering the slave on the master. In practice this reverts a
small part of patch for BUG 13963, the one related to the slave
connecting to the master.
The problem is a somewhat common misusage of the strmake function.
The strmake(dst, src, len) function writes at most /len/ bytes to
the string pointed to by src, not including the trailing null byte.
Hence, if /len/ is the exact length of the destination buffer, a
one byte buffer overflow can occur if the length of the source
string is equal to or greater than /len/.
The test allowed random coincidence of connection ids for two concurrent
sessions performing CREATE/DROP temp tables.
Fixed with correcting the test. The sessions connection ids are not changed
from their defaults anymore.
When compressed myisam files are opened, they are always memory mapped
sometimes causing memory swapping problems.
When we mmap the myisam compressed tables of size greater than the memory
available, the kswapd0 process utilization is very high consuming 30-40% of
the cpu. This happens only with linux kernels older than 2.6.9
With newer linux kernels, we don't have this problem of high cpu consumption
and this option may not be required.
The option 'myisam_mmap_size' is added to limit the amount of memory used for
memory mapping of myisam files. This option is not dynamic.
The default value on 32 bit system is 4294967295 bytes and on 64 bit system it
is 18446744073709547520 bytes.
Note: Testcase only tests the option variable. The actual bug has be to
tested manually.
returns incorrect results with where
An outer join of a const table (outer) and a normal table
(inner) with GROUP BY on a field from the outer table would
optimize away GROUP BY, and thus trigger the optimization to
do away with a temporary table if grouping was performed on
columns from the const table, hence executing the query with
filesort without temporary table. But this should not be
done if there is a non-indexed access to the inner table,
since filesort does not handle joins. It expects either ref
access, range ditto or table scan. The join condition will
thus not be applied.
Fixed by always forcing execution with temporary table in
the case of ROLLUP with a query involving an outer join. This
is a slightly broader class of queries than need fixing, but
it is hard to ascertain the position of a ROLLUP field wrt
outer join with current query representation.
Problem: inserting a record we don't set unused null bits in the
record buffer if no default field values used.
That may lead to wrong live checksum calculation.
Fix: set unused null bits in the record buffer in such cases.
The bug is caused by a race condition between the
INSERT DELAYED thread and the client thread's FLUSH TABLE. The
FLUSH TABLE does not guarantee (as is (wrongly) suggested in the
test case) that the INSERT DELAYED is ever executed. The
execution of the test case will thus not be deterministic.
The fix has been to do a deterministic verification that both
threads are complete by checking the content of the table.
strmov() is not guaranteed to work correctly on overlapping
source and destination buffers. On some OSes it may work,
but Fedora 12 has a stpcpy() that's not working correctly
on overlapping buffers.
Fixed to use the overlap-safe version of strmov instead.
Re-vitalized the overlap-safe version of strmov.
