When OOB is enabled, out-of-band commands are executed right away,
everything else is queued.  This lets out-of-band commands "jump the
queue".

However, certain errors are always reported right away, and therefore
can jump the queue even when the erroneous input does not request
out-of-band execution.  These errors are pretty unlikely to occur in
production, but it's wrong all the same.  Mark FIXME.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
---
 monitor.c        | 1 +
 tests/qmp-test.c | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/monitor.c b/monitor.c
index 51ba1485ad..28fa9b8d44 100644
--- a/monitor.c
+++ b/monitor.c
@@ -4338,6 +4338,7 @@ static void handle_qmp_command(JSONMessageParser *parser, GQueue *tokens)
     return;
 
 err:
+    /* FIXME overtakes queued in-band commands, wrong when !qmp_is_oob() */
     monitor_qmp_respond(mon, NULL, err, NULL);
     qobject_unref(req);
 }
diff --git a/tests/qmp-test.c b/tests/qmp-test.c
index 3f4e43bd2b..6581d1d755 100644
--- a/tests/qmp-test.c
+++ b/tests/qmp-test.c
@@ -242,6 +242,13 @@ static void test_qmp_oob(void)
     unblock_blocked_cmd();
     recv_cmd_id(qts, "ib-blocks-1");
     recv_cmd_id(qts, "ib-quick-1");
+
+    /* FIXME certain in-band errors overtake slow in-band command */
+    send_cmd_that_blocks(qts, "blocks-2");
+    qtest_async_qmp(qts, "{ 'id': 'err-2' }");
+    recv_cmd_id(qts, NULL);
+    unblock_blocked_cmd();
+    recv_cmd_id(qts, "blocks-2");
     cleanup_blocking_cmd();
 
     qtest_quit(qts);
-- 
2.17.1