Bug 326175 WBWRenderer arbitrarily modifies the window's parent's active context chain
The window's parent's context arbitrarily changes its active child to the window being rendered in createWidget(*).
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java
assertNotNull(sashContainer.getWidget());
		appContext.get(IPresentationEngine.class).removeGui(sashContainer);
		assertNull(sashContainer.getWidget());
	}
	public void testBug317849() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPartSashContainer sashContainer = BasicFactoryImpl.eINSTANCE
				.createPartSashContainer();
		window.getChildren().add(sashContainer);
		window.setSelectedElement(sashContainer);
		MPlaceholder sharedAreaPlaceholder = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		sashContainer.getChildren().add(sharedAreaPlaceholder);
		sashContainer.setSelectedElement(sharedAreaPlaceholder);
		MPartSashContainer sharedSashContainer = BasicFactoryImpl.eINSTANCE
				.createPartSashContainer();
		sharedAreaPlaceholder.setRef(sharedSashContainer);
		sharedSashContainer.setCurSharedRef(sharedAreaPlaceholder);
		MPartStack partStack = BasicFactoryImpl.eINSTANCE.createPartStack();
		sharedSashContainer.getChildren().add(partStack);
		sharedSashContainer.setSelectedElement(partStack);
		application.setContext(appContext);
		appContext.set(MApplication.class.getName(), application);
		wb = new E4Workbench(application, appContext);
		wb.createAndRunUI(window);
		assertNotNull(partStack.getWidget());