fix: more carefully use app in NetworkPrivate/NetworkTask (#6698)

CHANGELOG.md

@@ -34,6 +34,7 @@
 - Bugfix: Forward query params to websocket URLs. (#6141)
 - Bugfix: Fixed Lua errors from handlers of HTTP requests not being logged. (#6452)
 - Bugfix: Fixed restore button not showing on Windows. (#6565)
+- Bugfix: Fixed a crash that could occur when network requests were loading/saving cache as Chatterino was being shut down. (#6698)
 - Bugfix: Fixed popups and the overlay not being draggable on Wayland. (#6573)
 - Bugfix: Fixed middle-clicking usernames in a local channel opening an invalid viewercard. (#6577)
 - Bugfix: Added `desktop-entry` hint to Linux notifications. (#6615)

src/common/network/NetworkPrivate.cpp

@@ -59,8 +59,24 @@ void loadUncached(std::shared_ptr<NetworkData> &&data)
 
 void loadCached(std::shared_ptr<NetworkData> &&data)
 {
-    QFile cachedFile(getApp()->getPaths().cacheDirectory() + "/" +
-                     data->getHash());
+    if (isAppAboutToQuit())
+    {
+        qCDebug(chatterinoHTTP)
+            << "Skipping cached network load " << data->request.url()
+            << "because app is about to quit";
+        return;
+    }
+
+    auto *app = tryGetApp();
+    if (!app)
+    {
+        qCDebug(chatterinoHTTP)
+            << "Skipping cached network load " << data->request.url()
+            << "because app is about to quit";
+        return;
+    }
+
+    QFile cachedFile(app->getPaths().cacheDirectory() + "/" + data->getHash());
 
     if (!cachedFile.exists() || !cachedFile.open(QIODevice::ReadOnly))
     {

src/common/network/NetworkTask.cpp

@@ -141,7 +141,24 @@ void NetworkTask::logReply()
 void NetworkTask::writeToCache(const QByteArray &bytes) const
 {
     std::ignore = QtConcurrent::run([data = this->data_, bytes] {
-        QFile cachedFile(getApp()->getPaths().cacheDirectory() + "/" +
+        if (isAppAboutToQuit())
+        {
+            qCDebug(chatterinoHTTP)
+                << "Skipping cache write for" << data->request.url()
+                << "because app is about to quit";
+            return;
+        }
+
+        auto *app = tryGetApp();
+        if (!app)
+        {
+            qCDebug(chatterinoHTTP)
+                << "Skipping cache write for" << data->request.url()
+                << "because app is null";
+            return;
+        }
+
+        QFile cachedFile(app->getPaths().cacheDirectory() + "/" +
                          data->getHash());
 
         if (cachedFile.open(QIODevice::WriteOnly))