Please clarify some details of mysql_close_start/cont

Hi!

I was experimenting with some edge cases of mysql_close_start/cont and stumbled upon a case when the socket send buffer is full, and there is no reading done on the receiving side.

The problem in this case is that one should drive mysql_close_cont to completion to correctly dispose connection resources, however that completion might never happen, and it's unclear how to deal with it.

Right now i'm calling mariadb_cancel after some timeout and after that mysql_close_cont call seems to succeed, but i'm not sure whether or not is this approach correct/intended: could you please clarify this and shed some light on it in the documentation?