Fix crash if ui delegates are not deployedHEADdev

In case delegate for touch handle can not be loaded
bail out and simply return nullptr as TouchHandleDrawableQt
works fine without delegate (guards against nullptr).

Note all other dialog already bailout in case default delegate
can not be loaded.

Tested on bookworm with 6.8.3

Fixes: QTBUG-111907
Pick-to: 6.10 6.9 6.8
Change-Id: Ib509b63010888fa718f23148c06d973382cad428
Reviewed-by: Michael Brüning <[email protected]>

2 files changed, 7 insertions, 2 deletions

diff --git a/src/webenginequick/api/qquickwebengineview.cpp b/src/webenginequick/api/qquickwebengineview.cpp
index dae4a3753..ade8b451c 100644
--- a/src/webenginequick/api/qquickwebengineview.cpp
+++ b/src/webenginequick/api/qquickwebengineview.cpp
@@ -1450,8 +1450,9 @@ QQuickWebEngineViewPrivate::createTouchHandleDelegate(const QMap<int, QImage> &i
 {
     Q_Q(QQuickWebEngineView);
     // lifecycle managed by Chromium's TouchHandleDrawable
-    QQuickWebEngineTouchHandle *handle = new QQuickWebEngineTouchHandle();
+    QQuickWebEngineTouchHandle *handle(nullptr);
     if (m_touchHandleDelegate) {
+        handle = new QQuickWebEngineTouchHandle();
         QQmlContext *qmlContext = QQmlEngine::contextForObject(q);
         QQmlContext *context = new QQmlContext(qmlContext, handle);
         context->setContextObject(handle);
@@ -1462,7 +1463,9 @@ QQuickWebEngineViewPrivate::createTouchHandleDelegate(const QMap<int, QImage> &i
         handle->setItem(item, false);
     } else {
         QQuickItem *item = ui()->createTouchHandle();
-        Q_ASSERT(item);
+        if (!item) {
+            return nullptr;
+        }
         QQmlEngine *engine = qmlEngine(item);
         Q_ASSERT(engine);
         QQuickWebEngineTouchHandleProvider *touchHandleProvider =
@@ -1470,6 +1473,7 @@ QQuickWebEngineViewPrivate::createTouchHandleDelegate(const QMap<int, QImage> &i
                         engine->imageProvider(QQuickWebEngineTouchHandleProvider::identifier()));
         Q_ASSERT(touchHandleProvider);
         touchHandleProvider->init(images);
+        handle = new QQuickWebEngineTouchHandle();
         handle->setItem(item, true);
     }
     return handle;
diff --git a/src/webenginequick/ui_delegates_manager.cpp b/src/webenginequick/ui_delegates_manager.cpp
index f2488a7c2..93ac63422 100644
--- a/src/webenginequick/ui_delegates_manager.cpp
+++ b/src/webenginequick/ui_delegates_manager.cpp
@@ -154,6 +154,7 @@ bool UIDelegatesManager::ensureComponentLoaded(ComponentType type)
         }
         return true;
     }
+    qWarning("Default ui delegate %s can not be found.", qPrintable(fileName));
     return false;
 }