maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Alexey!

On Feb 14, Alexey Botchkov wrote:
> > But I don't understand that. Do you mean, old code did *not* suppress
> > errors here? How could selects from I_S tables work without it?
> 
> Here's how it works today:
> 
> get_all_tables()
>   Trigger_error_handler err_handler;
>   thd->push_internal_handler(&err_handler);
>   fill_schema_table_from_frm
>     get_table_share
>       .... /* here we get the error of file not found */
>         my_message_sql
>           THD::raise_condition
>             /* here we test the err_handler */
>             /* but it doesn't react on that kind of errors */
>             mysql_audit_notify()
>             stmt_da->set_error_status
>             warning_info->push_warning
>           /
>         /
>       .... /*error is returned back along the call stack */
>     /
>     thd->clear_error(); /*which erases all the fileopen errors*/
>   /
> 
> So basically the error is launched and then erased. Which doesn't help
> with the plugin notifications.
> To fix that i added one more error handler.

It's worse than that :)
After thd->clear_error() the error flag is cleared, indeed. But all
issued errors are still present in the warning list. I've looked into
this about found this little gem: do_fill_table() function.

It actually copies Warning_info list and removes warnings from there!

Could you, please remove that piece of fine creativity and
thd->clear_error() too and use the error handler instead?

Looking at the logic of do_fill_table(), all you need to do is to
filter out all errors, but keep all warnings. Like

  class Warnings_only_error_handler : public Internal_error_handler
  {
  public:
    bool handle_condition(THD *thd, uint sql_errno, const char* sqlstate,
                          MYSQL_ERROR::enum_warning_level level,
                          const char* msg, MYSQL_ERROR ** cond_hdl)
    {
      return level == MYSQL_ERROR::WARN_LEVEL_ERROR;
    }
  };


Regards,
Sergei