Bug 329482 Uninstantiated part may be rendered when closing another part in the same stack
1. Activate the 'Javadoc' view. 2. Activate the 'Package Explorer' view. 3. Shutdown. 4. Restart. 5. Ctrl+3 > Properties 6. Hide the 'Properties' view. 7. Now the 'Problems' view is the selected element. It should be the 'Javadoc' view.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
perspective.getChildren().add(areaPlaceholder);
		MPartStack stackB = BasicFactoryImpl.eINSTANCE.createPartStack();
		area.getChildren().add(stackB);
		area.setSelectedElement(stackB);
		MPart partB1 = BasicFactoryImpl.eINSTANCE.createPart();
		stackB.getChildren().add(partB1);
		stackB.setSelectedElement(partB1);
		MPart partB2 = BasicFactoryImpl.eINSTANCE.createPart();
		stackB.getChildren().add(partB2);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(partB1);
		partService.activate(partB2);
		partService.hidePart(partB2);
		assertEquals(partB1, stackB.getSelectedElement());
		assertEquals(partB1, partService.getActivePart());
		partService.hidePart(partB1);
		assertNull(stackB.getSelectedElement());
		assertEquals(partA, partService.getActivePart());
	}
	public void testHidePart_ActivationHistory13() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MArea area = AdvancedFactoryImpl.eINSTANCE.createArea();
		window.getSharedElements().add(area);
		MPart partB2 = BasicFactoryImpl.eINSTANCE.createPart();