All failing cases were attempts to use connection after
the server was brought down and restarted. Connections 
used client reconnect option.

The reason for failures is the behavior of sockets on Windows:
for a short period after crash (short enough to make the error 
not reproducible under debugger), write to socket on client
side would succeed but subsequent read would fail. 

MYSQL_OPT_RECONNECT does not really help in this case ,
because  in the case given here ,as  mysql_real_query() 
(which can handle reconnect option)  succeeds and 
mysql_read_results() (can't handle reconnect) fails.

The fix is adding --include wait_until_connected_again.inc to 
appropriate places in test. This ensures that read errors are 
caught and connection is recreated.