Description: fix notification of QDockWidget when it gets undocked
 Before the patch the notification was emitted only when the docker
 was attached to the panel or changed a position on it.
 .
 It looks like the old behavior was documented in a unittest,
 so this patch might actually be a "behavior change".
 .
 Note: https://mail.kde.org/pipermail/distributions/2019-April/000317.html
Origin: upstream, https://code.qt.io/cgit/qt/qtbase.git/commit/?id=06b8644953fc5267
Last-Update: 2019-06-14

--- a/src/widgets/widgets/qdockwidget.cpp
+++ b/src/widgets/widgets/qdockwidget.cpp
@@ -1171,6 +1171,8 @@ void QDockWidgetPrivate::setWindowState(
             QMainWindowLayout *mwlayout = qt_mainwindow_layout_from_dock(q);
             if (mwlayout)
                 emit q->dockLocationChanged(mwlayout->dockWidgetArea(q));
+        } else {
+            emit q->dockLocationChanged(Qt::NoDockWidgetArea);
         }
     }
 
--- a/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp
+++ b/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp
@@ -669,7 +669,11 @@ void tst_QDockWidget::dockLocationChange
     spy.clear();
 
     dw.setFloating(true);
-    QTest::qWait(100);
+    QTRY_COMPARE(spy.count(), 1);
+    QCOMPARE(qvariant_cast<Qt::DockWidgetArea>(spy.at(0).at(0)),
+             Qt::NoDockWidgetArea);
+    spy.clear();
+
     dw.setFloating(false);
     QTRY_COMPARE(spy.count(), 1);
     QCOMPARE(qvariant_cast<Qt::DockWidgetArea>(spy.at(0).at(0)),