re-implement QgisApp::removeDockWidget to remove dock widget action from panel menu when plugins are disabled (#4796)

Author: etiennesky

src/app/qgisapp.cpp

@@ -1852,6 +1852,12 @@ void QgisApp::addDockWidget( Qt::DockWidgetArea theArea, QDockWidget * thepDockW
   mMapCanvas->refresh();
 }
 
+void QgisApp::removeDockWidget( QDockWidget * thepDockWidget )
+{
+  QMainWindow::removeDockWidget( thepDockWidget );
+  mPanelMenu->removeAction( thepDockWidget->toggleViewAction() );
+}
+
 QToolBar *QgisApp::addToolBar( QString name )
 {
   QToolBar *toolBar = QMainWindow::addToolBar( name );

src/app/qgisapp.h

@@ -187,6 +187,7 @@ class QgisApp : public QMainWindow, private Ui::MainWindow
      * After adding the dock widget to the ui (by delegating to the QMainWindow
      * parent class, it will also add it to the View menu list of docks.*/
     void addDockWidget( Qt::DockWidgetArea area, QDockWidget * dockwidget );
+    void removeDockWidget( QDockWidget * dockwidget );
     /** Add a toolbar to the main window. Overloaded from QMainWindow.
      * After adding the toolbar to the ui (by delegating to the QMainWindow
      * parent class, it will also add it to the View menu list of toolbars.*/