Some menus where missing a setEmptyAction(EA_None) call.

Was exposed by fixing the empty action mechanism in
d7e7c342.

src/plugins/coreplugin/mainwindow.cpp

@@ -579,6 +579,7 @@ void MainWindow::registerDefaultActions()
     ActionContainer *ac = am->createMenu(Constants::M_FILE_RECENTFILES);
     mfile->addMenu(ac, Constants::G_FILE_OPEN);
     ac->menu()->setTitle(tr("Recent &Files"));
+    ac->setEmptyAction(ActionContainer::EA_None);
 
     // Save Action
     icon = QIcon::fromTheme(QLatin1String("document-save"), QIcon(Constants::ICON_SAVEFILE));

src/plugins/projectexplorer/projectexplorer.cpp

@@ -526,6 +526,7 @@ bool ProjectExplorerPlugin::initialize(const QStringList &arguments, QString *er
     Core::ActionContainer *mrecent =
         am->createMenu(Constants::M_RECENTPROJECTS);
     mrecent->menu()->setTitle(tr("Recent P&rojects"));
+    mrecent->setEmptyAction(Core::ActionContainer::EA_None);
     mfile->addMenu(mrecent, Core::Constants::G_FILE_OPEN);
     connect(mfile->menu(), SIGNAL(aboutToShow()),
         this, SLOT(updateRecentProjectMenu()));
@@ -548,6 +549,7 @@ bool ProjectExplorerPlugin::initialize(const QStringList &arguments, QString *er
     // session menu
     Core::ActionContainer *msession = am->createMenu(Constants::M_SESSION);
     msession->menu()->setTitle(tr("Session"));
+    msession->setEmptyAction(Core::ActionContainer::EA_None);
     mfile->addMenu(msession, Core::Constants::G_FILE_PROJECT);
     d->m_sessionMenu = msession->menu();
     connect(mfile->menu(), SIGNAL(aboutToShow()),