Bug 275171 [Contributions] Customize Perspective action breaks editor pinning action
Using M7, I enabled editor pinning (i.e. Reuse editor) and pinned an editor using an action in the toolbar. I then disabled editor pinning ad then opened the customized perspective dialog. After this, enabling/disabling editor pinning does not make the Pin Editor action reappear.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/WorkbenchActionBuilder.java
menu.add(new GroupMarker(IWorkbenchActionConstants.PROJ_END));
        menu.add(new Separator());
        menu.add(projectPropertyDialogAction);
        return menu;
    }
    /**
     * Creates and returns the Window menu.
     */
    private MenuManager createWindowMenu() {
        MenuManager menu = new MenuManager(
                IDEWorkbenchMessages.Workbench_window, IWorkbenchActionConstants.M_WINDOW);
        menu.add(newWindowAction);
		menu.add(newEditorAction);
		
        menu.add(new Separator());
        addPerspectiveActions(menu);
        menu.add(new Separator());
        addKeyboardShortcuts(menu);
        Separator sep = new Separator(IWorkbenchActionConstants.MB_ADDITIONS);
		sep.setVisible(!Util.isMac());
		menu.add(sep);
        
        
        ActionContributionItem openPreferencesItem = new ActionContributionItem(openPreferencesAction);
        openPreferencesItem.setVisible(!Util.isMac());
        menu.add(openPreferencesItem);
        menu.add(ContributionItemFactory.OPEN_WINDOWS.create(getWindow()));
        return menu;
    }
    /**