From 65b26acb7c86b8d278c4edb8308b09520ae09c9f Mon Sep 17 00:00:00 2001
From: Friedemann Kleint <Friedemann.Kleint@digia.com>
Date: Fri, 31 Jan 2014 13:22:24 +0100
Subject: [PATCH] Prevent crash and emit warning when receiving bogus drop
 events.

Task-number: QTBUG-33635

Change-Id: I6d436bc4d47d1d6b063fc2cf27d67fe4684e7491
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
---
 src/widgets/kernel/qwidgetwindow.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/widgets/kernel/qwidgetwindow.cpp b/src/widgets/kernel/qwidgetwindow.cpp
index 1cf13c880b..c7f8e18118 100644
--- a/src/widgets/kernel/qwidgetwindow.cpp
+++ b/src/widgets/kernel/qwidgetwindow.cpp
@@ -659,6 +659,11 @@ void QWidgetWindow::handleDragLeaveEvent(QDragLeaveEvent *event)
 
 void QWidgetWindow::handleDropEvent(QDropEvent *event)
 {
+    if (m_dragTarget.isNull()) {
+        qWarning() << Q_FUNC_INFO << m_widget << ": No drag target set.";
+        event->ignore();
+        return;
+    }
     const QPoint mapped = m_dragTarget.data()->mapFromGlobal(m_widget->mapToGlobal(event->pos()));
     QDropEvent translated(mapped, event->possibleActions(), event->mimeData(), event->mouseButtons(), event->keyboardModifiers());
     QGuiApplication::sendSpontaneousEvent(m_dragTarget.data(), &translated);