QMainWindow::restoreDockWidget(): Fix positioning of floating docks with native decoration.

Use QWidget::move() to position floating dock widgets.
Add a test for QMainWindow::restoreDockWidget().

Task-number: QTBUG-45780
Change-Id: I945917728a663916e8c225b9d3d2a75fa508d68f
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/src/widgets/widgets/qdockwidget.cpp b/src/widgets/widgets/qdockwidget.cpp
index db8d167b0d..21b0904cc0 100644
--- a/src/widgets/widgets/qdockwidget.cpp
+++ b/src/widgets/widgets/qdockwidget.cpp
@@ -1031,8 +1031,14 @@ void QDockWidgetPrivate::setWindowState(bool floating, bool unplug, const QRect
     q->setWindowFlags(flags);
 
 
-    if (!rect.isNull())
-        q->setGeometry(rect);
+    if (!rect.isNull()) {
+        if (floating) {
+            q->resize(rect.size());
+            q->move(rect.topLeft());
+        } else {
+            q->setGeometry(rect);
+        }
+    }
 
     updateButtons();