PROCEDURE, IF THE RESULT SET IS EMPTY.

Description:
============
When executing a prepared statement with a procedure call
with CURSOR_TYPE_READ_ONLY flag set, libmysqlclient hangs
when the procedure performs a SELECT query that returns
an empty result set.

Analysis:
=========
Generally, metadata result sets are no longer terminated
with EOF(now OK) packet. However, we have an exception when
a cursor is opened by the server in which case we can
have a metadata packet terminated by an EOF(now OK) packet.

For a simple SELECT query prepared to be executed, when a
client requests a cursor to be opened, the server can decide
to either open a cursor or send the result set rows.
1. If no cursor is opened by the server,
the packet sequence is -> <metadata><0 or more rows><OK>
2. If server opens a cursor, the packet sequence is
<metadata><OK><0 or more rows><OK>

The hang in the bug report happens for cases when
the server doesn't open a cursor and we have an empty
result set. In this case, the packet sequence sent by the
server is <metadata><OK>. Client should be able to figure
out that the OK packet following the metadata is the last
OK packet of the sequence and it indicates the end of rows
result-set. Hence, it need not perform any additional reads
which can cause such hangs.

Fix:
====
The solution is to check whether the server responded with
cursor or not and perform packet reads accordingly.