fix: ensure liveupdate pubsubs exit (#5557)

Previously, the derived class (i.e. BttvLiveUpdates or SeventvEventAPI)
    would have their destructor ran before BasicPubSubManager called
    stop, meaning there was a time wherein messages could still flow
    through, attempting to call `onMessage` on a pure virtual, causing a
    crash.

CHANGELOG.md

@@ -36,6 +36,7 @@
 - Bugfix: Fixed windows on Windows not saving correctly when snapping them to the edges. (#5478)
 - Bugfix: Fixed user info card popups adding duplicate line to log files. (#5499)
 - Bugfix: Fixed tooltips and input completion popups not working after moving a split. (#5541)
+- Bugfix: Fixed rare issue on shutdown where the client would hang. (#5557)
 - Bugfix: Fixed `/clearmessages` not working with more than one window. (#5489)
 - Bugfix: Fixed splits staying paused after unfocusing Chatterino in certain configurations. (#5504)
 - Bugfix: Links with invalid characters in the domain are no longer detected. (#5509)

src/providers/bttv/BttvLiveUpdates.cpp

@@ -15,6 +15,11 @@ BttvLiveUpdates::BttvLiveUpdates(QString host)
 {
 }
 
+BttvLiveUpdates::~BttvLiveUpdates()
+{
+    this->stop();
+}
+
 void BttvLiveUpdates::joinChannel(const QString &channelID,
                                   const QString &userName)
 {

src/providers/bttv/BttvLiveUpdates.hpp

@@ -19,6 +19,7 @@ class BttvLiveUpdates : public BasicPubSubManager<BttvLiveUpdateSubscription>
 
 public:
     BttvLiveUpdates(QString host);
+    ~BttvLiveUpdates() override;
 
     struct {
         Signal<BttvLiveUpdateEmoteUpdateAddMessage> emoteAdded;

src/providers/liveupdates/BasicPubSubManager.hpp

@@ -99,7 +99,8 @@ class BasicPubSubManager
 
     virtual ~BasicPubSubManager()
     {
-        this->stop();
+        // The derived class must call stop in its destructor
+        assert(this->stopping_);
     }
 
     BasicPubSubManager(const BasicPubSubManager &) = delete;
@@ -127,6 +128,11 @@ class BasicPubSubManager
 
     void stop()
     {
+        if (this->stopping_)
+        {
+            return;
+        }
+
         this->stopping_ = true;
 
         for (const auto &client : this->clients_)
@@ -138,10 +144,20 @@ class BasicPubSubManager
 
         if (this->mainThread_->joinable())
         {
-            this->mainThread_->join();
+            // NOTE: We spawn a new thread to join the websocket thread.
+            // There is a case where a new client was initiated but not added to the clients list.
+            // We just don't join the thread & let the operating system nuke the thread if joining fails
+            // within 1s.
+            auto joiner = std::async(std::launch::async, &std::thread::join,
+                                     this->mainThread_.get());
+            if (joiner.wait_for(std::chrono::seconds(1)) ==
+                std::future_status::timeout)
+            {
+                qCWarning(chatterinoLiveupdates)
+                    << "Thread didn't join within 1 second, rip it out";
+                this->websocketClient_.stop();
+            }
         }
-
-        assert(this->clients_.empty());
     }
 
 protected:

src/providers/seventv/SeventvEventAPI.cpp

@@ -26,6 +26,11 @@ SeventvEventAPI::SeventvEventAPI(
 {
 }
 
+SeventvEventAPI::~SeventvEventAPI()
+{
+    this->stop();
+}
+
 void SeventvEventAPI::subscribeUser(const QString &userID,
                                     const QString &emoteSetID)
 {

src/providers/seventv/SeventvEventAPI.hpp

@@ -33,6 +33,8 @@ class SeventvEventAPI
                     std::chrono::milliseconds defaultHeartbeatInterval =
                         std::chrono::milliseconds(25000));
 
+    ~SeventvEventAPI() override;
+
     struct {
         Signal<seventv::eventapi::EmoteAddDispatch> emoteAdded;
         Signal<seventv::eventapi::EmoteUpdateDispatch> emoteUpdated;

src/providers/twitch/PubSubManager.cpp

@@ -581,8 +581,6 @@ void PubSub::stop()
             this->websocketClient.stop();
         }
     }
-
-    assert(this->clients.empty());
 }
 
 bool PubSub::listenToWhispers()