sporadically
There are two problems:
1. When closing temporary tables, during the THD clean up - and
after the session connection was already closed, there is a
chance we can push an error into the THD diagnostics area, if
the writing of the implicit DROP event to the binary log fails
for some reason. As a consequence an assertion can be
triggered, because at that point the diagnostics area is
already set.
2. Using push_warning with MYSQL_ERROR::WARN_LEVEL_ERROR is a
bug.
Given that close_temporary_tables is mostly called from
THD::cleanup - ie, with the session already closed, we fix
problem #1 by allowing the diagnostics area to be
overwritten. There is one other place in the code that calls
close_temporary_tables - while applying Start_log_event_v3. To
cover that case, we make close_temporary_tables to return the
error, thus, propagating upwards in the stack.
To fix problem #2, we replace push_warning with sql_print_error.
sql/log_event.cc:
Added handling of error returned by close_temporary_tables to
Start_log_event_v3::do_apply_event.
sql/sql_base.cc:
Three changes to close_temporary_tables:
1. it returns a boolean now (instead of void)
2. it uses sql_print_error instead of push_warning when writing to
binary log fails
3. we set can_overwrite_status before writing to the binary log,
thence not risking triggering an assertion by any other push
into diagnostics area happening inside mysql_bin_log.write.
sql/sql_base.h:
Changed the interface of close_temporary_tables so that it returns
bool instead of void.
