Merge remote-tracking branch 'origin/5.12' into dev

Change-Id: I5dbdc13c6133e5b03e362c5461b4a599d781bd1e

2 files changed, 9 insertions, 1 deletions

diff --git a/src/widgets/kernel/qwidgetbackingstore.cpp b/src/widgets/kernel/qwidgetbackingstore.cpp
index b40c2d12ad..a32eb2a03b 100644
--- a/src/widgets/kernel/qwidgetbackingstore.cpp
+++ b/src/widgets/kernel/qwidgetbackingstore.cpp
@@ -101,6 +101,13 @@ void QWidgetBackingStore::qt_flush(QWidget *widget, const QRegion &region, QBack
 
     if (tlw->testAttribute(Qt::WA_DontShowOnScreen) || widget->testAttribute(Qt::WA_DontShowOnScreen))
         return;
+
+    // Foreign Windows do not have backing store content and must not be flushed
+    if (QWindow *widgetWindow = widget->windowHandle()) {
+        if (widgetWindow->type() == Qt::ForeignWindow)
+            return;
+    }
+
     static bool fpsDebug = qEnvironmentVariableIntValue("QT_DEBUG_FPS");
     if (fpsDebug) {
         if (!widgetBackingStore->perfFrames++)
diff --git a/src/widgets/kernel/qwidgetwindow.cpp b/src/widgets/kernel/qwidgetwindow.cpp
index 0b2d72f330..279c6c0282 100644
--- a/src/widgets/kernel/qwidgetwindow.cpp
+++ b/src/widgets/kernel/qwidgetwindow.cpp
@@ -642,7 +642,8 @@ void QWidgetWindow::handleMouseEvent(QMouseEvent *event)
     if (!widget)
         widget = m_widget;
 
-    if (event->type() == QEvent::MouseButtonPress)
+    const bool initialPress = event->buttons() == event->button();
+    if (event->type() == QEvent::MouseButtonPress && initialPress)
         qt_button_down = widget;
 
     QWidget *receiver = QApplicationPrivate::pickMouseReceiver(m_widget, event->windowPos().toPoint(), &mapped, event->type(), event->buttons(),