From 8a78830b0d7020c83f7f739165ab865f04440a74 Mon Sep 17 00:00:00 2001
From: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Date: Tue, 7 Jul 2020 13:54:49 +0200
Subject: [PATCH] Item widgets: fix crash in mimeTypes()

*Always* check the result of a dynamic/qobject cast. I'm not positive
if the cast is correct (or should it just be a static cast),
but in principle these models can be used with a different view.

Change-Id: I37108cbb2744b6bf0fb46392d1cc9883f2d0b60e
Pick-to: 5.15
Reviewed-by: Samuel Gaist <samuel.gaist@idiap.ch>
---
 src/widgets/itemviews/qlistwidget.cpp | 4 +++-
 src/widgets/itemviews/qtreewidget.cpp | 5 ++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/widgets/itemviews/qlistwidget.cpp b/src/widgets/itemviews/qlistwidget.cpp
index 176f72a471..ca7439b08c 100644
--- a/src/widgets/itemviews/qlistwidget.cpp
+++ b/src/widgets/itemviews/qlistwidget.cpp
@@ -463,7 +463,9 @@ void QListModel::itemChanged(QListWidgetItem *item, const QList<int> &roles)
 QStringList QListModel::mimeTypes() const
 {
     const QListWidget *view = qobject_cast<const QListWidget*>(QObject::parent());
-    return view->mimeTypes();
+    if (view)
+        return view->mimeTypes();
+    return {};
 }
 
 QMimeData *QListModel::internalMimeData()  const
diff --git a/src/widgets/itemviews/qtreewidget.cpp b/src/widgets/itemviews/qtreewidget.cpp
index a186a243fd..f5434100b9 100644
--- a/src/widgets/itemviews/qtreewidget.cpp
+++ b/src/widgets/itemviews/qtreewidget.cpp
@@ -738,7 +738,10 @@ QList<QTreeWidgetItem*>::iterator QTreeModel::sortedInsertionIterator(
 
 QStringList QTreeModel::mimeTypes() const
 {
-    return view()->mimeTypes();
+    auto v = view();
+    if (v)
+        return v->mimeTypes();
+    return {};
 }
 
 QMimeData *QTreeModel::internalMimeData()  const