Fix attach crash on complex Qt applications

core/probe.cpp

@@ -865,7 +865,17 @@ void Probe::discoverObject(QObject *object)
         return;
 
     objectAdded(object);
-    foreach (QObject *child, object->children()) {
+
+    // foreach (QObject *child, object->children()) {
+    //     discoverObject(child);
+    // }
+
+    const auto children = object->children();
+    for (QObject *child : children) {
+        if (!child)
+            continue;
+        if (m_validObjects.contains(child))
+            continue;
         discoverObject(child);
     }
 }

plugins/quickinspector/quickinspector.cpp

@@ -512,16 +512,27 @@ void QuickInspector::objectCreated(QObject *object)
 {
     if (QQuickWindow *window = qobject_cast<QQuickWindow *>(object)) {
         if (QQuickView *view = qobject_cast<QQuickView *>(object)) {
-            m_probe->discoverObject(view->engine());
+            if (view->engine()) {
+                m_probe->discoverObject(view->engine());
+            }
         } else {
             QQmlContext *context = QQmlEngine::contextForObject(window);
             QQmlEngine *engine = context ? context->engine() : nullptr;
 
             if (!engine) {
-                engine = qmlEngine(window->contentItem()->childItems().value(0));
+                // engine = qmlEngine(window->contentItem()->childItems().value(0));
+                QQuickItem *contentItem = window->contentItem();
+                if (contentItem) {
+                    const auto children = contentItem->childItems();
+                    if (!children.isEmpty()) {
+                        engine = qmlEngine(children.first());
+                    }
+                }
             }
 
-            m_probe->discoverObject(engine);
+            if (engine) {
+                m_probe->discoverObject(engine);
+            }
         }
     }
 }

probe/hooks.cpp

@@ -133,6 +133,10 @@ extern "C" Q_DECL_EXPORT void gammaray_probe_attach()
     if (!qApp) {
         return;
     }
+
+    Hooks::installHooks();
+    Probe::startupHookReceived();
+
     log_injection("gammaray_probe_attach()\n");
     new ProbeCreator(ProbeCreator::Create | ProbeCreator::FindExistingObjects | ProbeCreator::ResendServerAddress);
 } // NOLINT(clang-analyzer-cplusplus.NewDeleteLeaks)