Merge remote-tracking branch 'origin/5.8' into dev

Change-Id: I3b51bb706e401edfda09a433c67aa58e44f33e83

1 files changed, 4 insertions, 2 deletions

diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index 7b60e9cb56..879f085f11 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -692,12 +692,14 @@ void QFileDialogPrivate::emitFilesSelected(const QStringList &files)
 
 bool QFileDialogPrivate::canBeNativeDialog() const
 {
-    Q_Q(const QFileDialog);
+    // Don't use Q_Q here! This function is called from ~QDialog,
+    // so Q_Q calling q_func() invokes undefined behavior (invalid cast in q_func()).
+    const QDialog * const q = static_cast<const QDialog*>(q_ptr);
     if (nativeDialogInUse)
         return true;
     if (QCoreApplication::testAttribute(Qt::AA_DontUseNativeDialogs)
         || q->testAttribute(Qt::WA_DontShowOnScreen)
-        || (q->options() & QFileDialog::DontUseNativeDialog)) {
+        || (options->options() & QFileDialog::DontUseNativeDialog)) {
         return false;
     }