Scene Cache Can Become Stale

[LinuxMainframe]

Medium: Scene Cache Can Become Stale

Priority: MEDIUM

Type: Logic Issue

Location

libwsv5.c line 2015 in obsws_set_current_scene()

Issue

Scene cache optimization can skip necessary scene switches if events are delayed:

pthread_mutex_lock(&conn->scene_mutex);
bool already_current = (conn->current_scene && strcmp(conn->current_scene, scene_name) == 0);
pthread_mutex_unlock(&conn->scene_mutex);

if (already_current) {
    obsws_log(conn, OBSWS_LOG_DEBUG, "Already on scene: %s", scene_name);
    if (response) {
        *response = calloc(1, sizeof(obsws_response_t));
        (*response)->success = true;
    }
    return OBSWS_OK;  // ← Returns without actually switching!
}

Scenario

1. User switches scene via OBS UI: Scene1 → Scene2
2. Event notification is delayed (network lag, busy OBS)
3. Cache still shows "Scene1"
4. Application calls obsws_set_current_scene(conn, "Scene2", ...)
5. Function thinks Scene2 is current, returns without switching
6. Scene is actually Scene1, not Scene2

Impact

• Rare edge case but could cause confusion
• Application thinks scene switched but it didn't
• Scene gets out of sync with application state