Merge remote-tracking branch 'origin/5.8' into 5.9

Conflicts:
	mkspecs/features/moc.prf

Change-Id: Ia71c8e3b3185f7c999bf226d0675051b10b8740b

1 files changed, 13 insertions, 0 deletions

diff --git a/src/widgets/widgets/qdockwidget.cpp b/src/widgets/widgets/qdockwidget.cpp
index aa5d809431..307a261a43 100644
--- a/src/widgets/widgets/qdockwidget.cpp
+++ b/src/widgets/widgets/qdockwidget.cpp
@@ -1026,6 +1026,12 @@ void QDockWidgetPrivate::nonClientAreaMouseEvent(QMouseEvent *event)
     }
 }
 
+void QDockWidgetPrivate::recalculatePressPos(QResizeEvent *event)
+{
+    qreal ratio = event->oldSize().width() / (1.0 * event->size().width());
+    state->pressPos.setX(state->pressPos.x() / ratio);
+}
+
 /*! \internal
     Called when the QDockWidget or the QDockWidgetGroupWindow is moved
  */
@@ -1542,6 +1548,13 @@ bool QDockWidget::event(QEvent *event)
         // if the mainwindow is plugging us, we don't want to update undocked geometry
         if (isFloating() && layout != 0 && layout->pluggingWidget != this)
             d->undockedGeometry = geometry();
+
+        // Usually the window won't get resized while it's being moved, but it can happen,
+        // for example on Windows when moving to a screen with bigger scale factor
+        // (and Qt::AA_EnableHighDpiScaling is enabled). If that happens we should
+        // update state->pressPos, otherwise it will be outside the window when the window shrinks.
+        if (d->state && d->state->dragging)
+            d->recalculatePressPos(static_cast<QResizeEvent*>(event));
         break;
     default:
         break;