Problem: the test set @@global.init_slave to garbage at a time
which was not guaranteed to be after the time when the slave's
SQL thread used it. That would cause the slave's SQL thread to
stop in rare cases.
Fix: The test does not care about the value of
@@global.init_slave, except that it should be different on
master and slave. Hence, we set @@global.init_slave to
something that is valid SQL.
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-test/t/variables.test, because:
- mysql-test/suite/rpl/t/rpl_variables.test does not replicate anything,
so should not be in the rpl suite.
- mysql-test/t/variables.test is the place for testing variable-related
problems and features.
- I will soon commit a patch containing a test case that tests
replication of variables. It would be good if I could call the test case
mysql-test/suite/rpl/t/rpl_variables.test. I'm making place for that now.
