5 files changed, 30 insertions, 40 deletions

diff --git a/src/quick/util/qquickanimatorjob.cpp b/src/quick/util/qquickanimatorjob.cpp
index 3ac02cd259..a7950e2b33 100644
--- a/src/quick/util/qquickanimatorjob.cpp
+++ b/src/quick/util/qquickanimatorjob.cpp
@@ -321,8 +321,10 @@ void QQuickTransformAnimatorJob::preSync()
         m_helper = nullptr;
     }
 
-    if (!m_target)
+    if (!m_target) {
+        invalidate();
         return;
+    }
 
     if (!m_helper) {
         m_helper = qquick_transform_animatorjob_helper_store()->acquire(m_target);
@@ -342,27 +344,6 @@ void QQuickTransformAnimatorJob::preSync()
     m_helper->sync();
 }
 
-void QQuickTransformAnimatorJob::postSync()
-{
-    Q_ASSERT((m_helper != nullptr) == (m_target != nullptr)); // If there is a target, there should also be a helper, ref: preSync
-    Q_ASSERT(!m_helper || m_helper->item == m_target); // If there is a helper, it should point to our target
-
-    if (!m_target || !m_helper) {
-        invalidate();
-        return;
-    }
-
-    QQuickItemPrivate *d = QQuickItemPrivate::get(m_target);
-#if QT_CONFIG(quick_shadereffect)
-    if (d->extra.isAllocated()
-            && d->extra->layer
-            && d->extra->layer->enabled()) {
-        d = QQuickItemPrivate::get(d->extra->layer->m_effectSource);
-    }
-#endif
-    m_helper->node = d->itemNode();
-}
-
 void QQuickTransformAnimatorJob::invalidate()
 {
     if (m_helper)
diff --git a/src/quick/util/qquickanimatorjob_p.h b/src/quick/util/qquickanimatorjob_p.h
index a3ced4c21b..777da2ee6c 100644
--- a/src/quick/util/qquickanimatorjob_p.h
+++ b/src/quick/util/qquickanimatorjob_p.h
@@ -235,7 +235,6 @@ public:
 
 protected:
     QQuickTransformAnimatorJob();
-    void postSync() override;
     void invalidate() override;
 
     Helper *m_helper;
diff --git a/src/quick/util/qquickglobal.cpp b/src/quick/util/qquickglobal.cpp
index 5ba849c57f..2070fd7ff0 100644
--- a/src/quick/util/qquickglobal.cpp
+++ b/src/quick/util/qquickglobal.cpp
@@ -61,7 +61,7 @@ QT_BEGIN_NAMESPACE
 class QQuickColorProvider : public QQmlColorProvider
 {
 public:
-    QVariant colorFromString(const QString &s, bool *ok)
+    QVariant colorFromString(const QString &s, bool *ok) override
     {
         QColor c(s);
         if (c.isValid()) {
@@ -73,7 +73,7 @@ public:
         return QVariant();
     }
 
-    unsigned rgbaFromString(const QString &s, bool *ok)
+    unsigned rgbaFromString(const QString &s, bool *ok) override
     {
         QColor c(s);
         if (c.isValid()) {
@@ -95,36 +95,36 @@ public:
         return QString();
     }
 
-    QVariant fromRgbF(double r, double g, double b, double a)
+    QVariant fromRgbF(double r, double g, double b, double a) override
     {
         return QVariant(QColor::fromRgbF(r, g, b, a));
     }
 
-    QVariant fromHslF(double h, double s, double l, double a)
+    QVariant fromHslF(double h, double s, double l, double a) override
     {
         return QVariant(QColor::fromHslF(h, s, l, a));
     }
 
-    QVariant fromHsvF(double h, double s, double v, double a)
+    QVariant fromHsvF(double h, double s, double v, double a) override
     {
         return QVariant(QColor::fromHsvF(h, s, v, a));
     }
 
-    QVariant lighter(const QVariant &var, qreal factor)
+    QVariant lighter(const QVariant &var, qreal factor) override
     {
         QColor color = var.value<QColor>();
         color = color.lighter(int(qRound(factor*100.)));
         return QVariant::fromValue(color);
     }
 
-    QVariant darker(const QVariant &var, qreal factor)
+    QVariant darker(const QVariant &var, qreal factor) override
     {
         QColor color = var.value<QColor>();
         color = color.darker(int(qRound(factor*100.)));
         return QVariant::fromValue(color);
     }
 
-    QVariant tint(const QVariant &baseVar, const QVariant &tintVar)
+    QVariant tint(const QVariant &baseVar, const QVariant &tintVar) override
     {
         QColor tintColor = tintVar.value<QColor>();
 
@@ -778,13 +778,13 @@ public:
 class QQuickGuiProvider : public QQmlGuiProvider
 {
 public:
-    QQuickApplication *application(QObject *parent)
+    QQuickApplication *application(QObject *parent) override
     {
         return new QQuickApplication(parent);
     }
 
 #if QT_CONFIG(im)
-    QInputMethod *inputMethod()
+    QInputMethod *inputMethod() override
     {
         QInputMethod *im = qGuiApp->inputMethod();
         QQmlEngine::setObjectOwnership(im, QQmlEngine::CppOwnership);
@@ -792,20 +792,20 @@ public:
     }
 #endif
 
-    QStyleHints *styleHints()
+    QStyleHints *styleHints() override
     {
         QStyleHints *sh = qGuiApp->styleHints();
         QQmlEngine::setObjectOwnership(sh, QQmlEngine::CppOwnership);
         return sh;
     }
 
-    QStringList fontFamilies()
+    QStringList fontFamilies() override
     {
         QFontDatabase database;
         return database.families();
     }
 
-    bool openUrlExternally(QUrl &url)
+    bool openUrlExternally(QUrl &url) override
     {
 #ifndef QT_NO_DESKTOPSERVICES
         return QDesktopServices::openUrl(url);
diff --git a/src/quick/util/qquickimageprovider.cpp b/src/quick/util/qquickimageprovider.cpp
index c80025f968..b4a6b9e1f6 100644
--- a/src/quick/util/qquickimageprovider.cpp
+++ b/src/quick/util/qquickimageprovider.cpp
@@ -183,7 +183,12 @@ QString QQuickImageResponse::errorString() const
 
     It may be reimplemented to cancel a request in the provider side, however, it is not mandatory.
 
-    A cancelled QQuickImageResponse still needs to emit finished().
+    A cancelled QQuickImageResponse still needs to emit finished() so that the
+    engine may clean up the QQuickImageResponse.
+
+    \note finished() should not be emitted until the response is complete,
+    regardless of whether or not cancel() was called. If it is called prematurely,
+    the engine may destroy the response while it is still active, leading to a crash.
 */
 void QQuickImageResponse::cancel()
 {
@@ -192,7 +197,12 @@ void QQuickImageResponse::cancel()
 /*!
     \fn void QQuickImageResponse::finished()
 
-    Signals that the job execution has finished (be it successfully, because an error happened or because it was cancelled).
+    Signals that the job execution has finished (be it successfully, because an
+    error happened or because it was cancelled).
+
+    \note Emission of this signal must be the final action the response performs:
+    once the signal is received, the response will subsequently be destroyed by
+    the engine.
  */
 
 /*!
diff --git a/src/quick/util/qquickpixmapcache.cpp b/src/quick/util/qquickpixmapcache.cpp
index 882482ad31..e026608150 100644
--- a/src/quick/util/qquickpixmapcache.cpp
+++ b/src/quick/util/qquickpixmapcache.cpp
@@ -162,7 +162,7 @@ Q_SIGNALS:
     void downloadProgress(qint64, qint64);
 
 protected:
-    bool event(QEvent *event);
+    bool event(QEvent *event) override;
 
 private:
     Q_DISABLE_COPY(QQuickPixmapReply)
@@ -200,7 +200,7 @@ public:
     static QQuickPixmapReader *existingInstance(QQmlEngine *engine);
 
 protected:
-    void run();
+    void run() override;
 
 private:
     friend class QQuickPixmapReaderThreadObject;