Crash by a NULL dereferencing of stmt->mysql in mysql_stmt_reset

Hi,

I have a similar crash as CONC-83 in same conditions, but the computer was not in suspended state, but in idle state, which means that only few requests were done and timeout may happen. From server side, we use default configuration options except: max_allowed_packet=16M
From client side, reconnect option is enabled.

We still use a old revision 122, but it seems meanwhile, there is no major updates to the code.

Best Regards,
Eric