Exclude retiring capture sessions from new subscriptions

tools/chatgui/src/audio_capture.cpp

@@ -16,7 +16,7 @@ struct AudioCapture::Session {
     AudioDevice device;
     QString key;
     std::array<Slot, 2> consumers;
-    bool streamProfile = false;
+    bool streamProfile = false, retiring = false;
     int requestedChannels = 1, channels = 1;
     uint64_t tag = 0;
     QElapsedTimer clock;
@@ -108,7 +108,7 @@ bool AudioCapture::open(const QString& input, Role role, int channels, uint64_t
     for (auto it = sessions.begin(); it != sessions.end();) {
         auto session = it->lock();
         if (!session) { it = sessions.erase(it); continue; }
-        if (session->key == key) m_session = session;
+        if (!session->retiring && session->key == key) m_session = session;
         ++it;
     }
     if (!m_session) { m_session = std::make_shared<Session>(key); sessions.push_back(m_session); }
@@ -151,6 +151,7 @@ void AudioCapture::closeAsync() {
     if (m_closeThread.joinable()) m_closeThread.join();
     auto session = detach();
     if (!session) return;
+    if (session.use_count() == 1) session->retiring = true;
     m_closeDone.store(false, std::memory_order_release);
     DEBUG_INFO(DEBUG_CATEGORY_CALL, "capture: asynchronous close started shared=%d", session.use_count() > 1);
     try {