qmp: Fix device-list-properties not to crash for abstract device

Broken in commit f4eb32b "qmp: show QOM properties in
device-list-properties", v2.1.

Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Message-Id: <1443689999-12182-9-git-send-email-armbru@redhat.com>

qmp.c

@@ -515,6 +515,12 @@ DevicePropertyInfoList *qmp_device_list_properties(const char *typename,
         return NULL;
     }
 
+    if (object_class_is_abstract(klass)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "name",
+                   "non-abstract device type");
+        return NULL;
+    }
+
     obj = object_new(typename);
 
     QTAILQ_FOREACH(prop, &obj->properties, node) {

tests/device-introspect-test.c

@@ -45,17 +45,10 @@ static void test_one_device(const char *type)
     QDict *resp;
     char *help, *qom_tree;
 
-    /*
-     * Skip this part for the abstract device test case, because
-     * device-list-properties crashes for such devices.
-     * FIXME fix it not to crash
-     */
-    if (strcmp(type, "device")) {
-        resp = qmp("{'execute': 'device-list-properties',"
-                   " 'arguments': {'typename': %s}}",
-                   type);
-        QDECREF(resp);
-    }
+    resp = qmp("{'execute': 'device-list-properties',"
+               " 'arguments': {'typename': %s}}",
+               type);
+    QDECREF(resp);
 
     help = hmp("device_add \"%s,help\"", type);
     g_free(help);