The code for executing indexed ORDER BY was not setting all the
internal fields correctly when selecting to execute ORDER BY over
and index.
Fixed by change the access method to one that will use the
quick indexed access if one is selected while selecting indexed
ORDER BY.
The bug is a regression introduced in 5.1 by the patch for bug28404.
Under some circumstances test_if_skip_sort_order() could leave some
data structures in an inconsistent state so that some parts of code
could assume the selected execution strategy for GROUP BY/DISTINCT as
a loose index scan (e.g. JOIN_TAB::is_using_loose_index_scan()), while
the actual strategy chosen was an ordered index scan, which led to
wrong data being returned.
Fixed test_if_skip_sort_order() so that when changing the type for a
join table, select->quick is reset not only for EXPLAIN, but for the
actual join execution as well, to not confuse code that depends on its
value to determine the chosen GROUP BY/DISTINCT strategy.
When trying to get the requested amount of memory for the keybuffer,
the out of memory could be signaled if one of the tentative allocations
fail. Later the server would crash (debug assert) when trying to send
a ok packet with a error set.
The solution is only to signal the error if all tentative allocations
for the keybuffer fail.
The server used to trust blindly information from the client about
its capabilities. During the connection handshake the server sends
information about what it supports and then the client sends back a
set of capabilities which cover all of the server's or less.
Before this changeset the server didn't check whether the flags sent
by the client were valid for the server. For example, if the server
doesn't support compressed protocol but the client does and sends that
bit turned on, the server didn't check it. The change make the server code
less error prone to problems related to the value of THD::client_capabilities.
Clearly there is no vulnerability being fixed but this is a maintainenance
fix to prevent misusage in the future.
Problem: rpl_variables_stm.test used a character set and a collation which
are not included on all platforms.
Fix: replace the character set and collation by ones that are included on
all platforms. (rpl_variables_stm does not rely on which character set is
used, the only important aspect is the fact that it changes.)
Problem: if the IO slave thread is attempting to connect,
STOP SLAVE waits for the attempt to finish.
It may take a long time.
Fix: don't wait, stop the slave immediately.
The reason is that we are using a sleep to wait for slave to reach the
slave_transaction_retries limit.
Fix: wait for the slave to stop instead. This is what we want to do, since
the slave stops when the limit is reached.
WHERE f1 < n ignored row if f1 was indexed integer column and
f1 = TYPE_MAX ^ n = TYPE_MAX+1. The latter value when treated
as TYPE overflowed (obviously). This was not handled, it is now.
Affected tests fixing. After the fix for st_relay_log_info::wait_for_pos() that
handles widely used select('master-bin.xxxx',pos) invoked by mysqltest
there appeared to be four tests that either tried synchronizing when
the slave was stopped or used incorrect synchronization method like
to call `sync_with_master' from the current connection being to the
master itself.
Fixed with correcting the current connection or/and using the correct
synchronization macro when possible.
Problem: in mixed and statement mode, a query that refers to a
system variable will use the slave's value when replayed on
slave. So if the value of a system variable is inserted into a
table, the slave will differ from the master.
Fix: mark statements that refer to a system variable as "unsafe",
meaning they will be replicated by row in mixed mode and produce a warning
in statement mode. There are some exceptions: some variables are actually
replicated. Those should *not* be marked as unsafe.
BUG#34732: mysqlbinlog does not print default values for auto_increment variables
Problem: mysqlbinlog does not print default values for some variables,
including auto_increment_increment and others. So if a client executing
the output of mysqlbinlog has different default values, replication will
be wrong.
Fix: Always print default values for all variables that are replicated.
I need to fix the two bugs at the same time, because the test cases would
fail if I only fixed one of them.
MYSQL_TYPE_NEWDECIMAL
Added support for the type MYSQL_TYPE_NEWDECIMAL. It now works like
MYSQL_TYPE_DECIMAL. Unfortunately there cannot be a test case until
we have a working information_schema plugin as part of the source
distribution.
