[PATCH] qmp: Reset mon->commands on CHR_EVENT_CLOSED

[Jason Andryuk <jandryuk@gmail.com>]

Currently, mon->commands is uninitialized until CHR_EVENT_OPENED where
it is set to &qmp_cap_negotiation_commands.  After capability
negotiation, it is set to &qmp_commands.  If the chardev is closed,
CHR_EVENT_CLOSED, mon->commands remains as &qmp_commands.  Only once the
chardev is re-opened with CHR_EVENT_OPENED, is it reset to
&qmp_cap_negotiation_commands.

monitor_qapi_event_emit compares mon->commands to
&qmp_cap_negotiation_commands, and skips sending events when they are
equal.  In the case of a closed chardev, QMP events are still sent down
to the closed chardev which needs to drop them.

Set mon->commands to &qmp_cap_negotiation_commands for CHR_EVENT_CLOSED
to stop sending events.  Setting for the CHR_EVENT_OPENED case remains
since that is how mon->commands is set for a newly opened connections.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
---
 monitor/qmp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/monitor/qmp.c b/monitor/qmp.c
index 9d9e5d8b27..5e2073c5eb 100644
--- a/monitor/qmp.c
+++ b/monitor/qmp.c
@@ -333,6 +333,7 @@ static void monitor_qmp_event(void *opaque, int event)
          * is closed.
          */
         monitor_qmp_cleanup_queues(mon);
+        mon->commands = &qmp_cap_negotiation_commands;
         json_message_parser_destroy(&mon->parser);
         json_message_parser_init(&mon->parser, handle_qmp_command,
                                  mon, NULL);
-- 
2.21.0