tests: add qmp/missing-any-arg test

test_qmp_missing_any_arg() is about a bug in infrastructure used by
the QMP core, fixed in commit c4897802.  We covered the bug in
infrastructure unit tests (commit bce3035a).  Let's test
it at the QMP level as well.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
[thuth: Tweaked the commit message according to Markus' suggestion]
Signed-off-by: NThomas Huth <thuth@redhat.com>

tests/qmp-test.c

@@ -318,6 +318,19 @@ static void test_qmp_preconfig(void)
     qtest_quit(qs);
 }
 
+static void test_qmp_missing_any_arg(void)
+{
+    QTestState *qts;
+    QDict *resp;
+
+    qts = qtest_init(common_args);
+    resp = qtest_qmp(qts, "{'execute': 'qom-set', 'arguments':"
+                     " { 'path': '/machine', 'property': 'rtc-time' } }");
+    g_assert_nonnull(resp);
+    qmp_assert_error_class(resp, "GenericError");
+    qtest_quit(qts);
+}
+
 int main(int argc, char *argv[])
 {
     g_test_init(&argc, &argv, NULL);
@@ -325,6 +338,7 @@ int main(int argc, char *argv[])
     qtest_add_func("qmp/protocol", test_qmp_protocol);
     qtest_add_func("qmp/oob", test_qmp_oob);
     qtest_add_func("qmp/preconfig", test_qmp_preconfig);
+    qtest_add_func("qmp/missing-any-arg", test_qmp_missing_any_arg);
 
     return g_test_run();
 }