Merge remote-tracking branch 'origin/5.14' into 5.15

Change-Id: Ib4df563fc7b1f7c40f425e0e71180d9517a672be

4 files changed, 14 insertions, 9 deletions

diff --git a/src/gui/kernel/qdnd.cpp b/src/gui/kernel/qdnd.cpp
index 5c5f166554..dd541af3b8 100644
--- a/src/gui/kernel/qdnd.cpp
+++ b/src/gui/kernel/qdnd.cpp
@@ -113,11 +113,12 @@ Qt::DropAction QDragManager::drag(QDrag *o)
 
     m_object->d_func()->target = 0;
 
-    QGuiApplicationPrivate::instance()->notifyDragStarted(o);
+    QGuiApplicationPrivate::instance()->notifyDragStarted(m_object.data());
     const Qt::DropAction result = m_platformDrag->drag(m_object);
-    m_object = 0;
-    if (!m_platformDrag->ownsDragObject())
-        o->deleteLater();
+    if (!m_object.isNull() && !m_platformDrag->ownsDragObject())
+        m_object->deleteLater();
+
+    m_object.clear();
     return result;
 }
 
diff --git a/src/gui/kernel/qdnd_p.h b/src/gui/kernel/qdnd_p.h
index b1219c8658..abb30986a5 100644
--- a/src/gui/kernel/qdnd_p.h
+++ b/src/gui/kernel/qdnd_p.h
@@ -101,13 +101,13 @@ public:
     void setCurrentTarget(QObject *target, bool dropped = false);
     QObject *currentTarget() const;
 
-    QDrag *object() const { return m_object; }
+    QPointer<QDrag> object() const { return m_object; }
     QObject *source() const;
 
 private:
     QObject *m_currentDropTarget;
     QPlatformDrag *m_platformDrag;
-    QDrag *m_object;
+    QPointer<QDrag> m_object;
 
     static QDragManager *m_instance;
     Q_DISABLE_COPY_MOVE(QDragManager)
diff --git a/src/gui/kernel/qdrag.cpp b/src/gui/kernel/qdrag.cpp
index dcd0d13d5c..8e2f7be23e 100644
--- a/src/gui/kernel/qdrag.cpp
+++ b/src/gui/kernel/qdrag.cpp
@@ -279,8 +279,11 @@ Qt::DropAction QDrag::exec(Qt::DropActions supportedActions, Qt::DropAction defa
     }
     d->supported_actions = supportedActions;
     d->default_action = transformedDefaultDropAction;
-    d->executed_action = QDragManager::self()->drag(this);
-
+    QPointer<QDrag> self = this;
+    auto executed_action = QDragManager::self()->drag(self.data());
+    if (self.isNull())
+        return Qt::IgnoreAction;
+    d->executed_action = executed_action;
     return d->executed_action;
 }
 
diff --git a/src/gui/kernel/qwindowsysteminterface.cpp b/src/gui/kernel/qwindowsysteminterface.cpp
index 4f1056e906..ba04f8701d 100644
--- a/src/gui/kernel/qwindowsysteminterface.cpp
+++ b/src/gui/kernel/qwindowsysteminterface.cpp
@@ -828,7 +828,8 @@ void QWindowSystemInterface::handleScreenAdded(QPlatformScreen *ps, bool isPrima
 */
 void QWindowSystemInterface::handleScreenRemoved(QPlatformScreen *platformScreen)
 {
-    // Important to keep this order since the QSceen doesn't own the platform screen
+    // Important to keep this order since the QSceen doesn't own the platform screen.
+    // The QScreen destructor will take care changing the primary screen, so no need here.
     delete platformScreen->screen();
     delete platformScreen;
 }