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
placeholderB.setRef(partB);
		partB.setCurSharedRef(placeholderB);
		partStack.getChildren().add(placeholderB);
		MPlaceholder placeholderC = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderC.setRef(partC);
		partC.setCurSharedRef(placeholderC);
		partStack.getChildren().add(placeholderC);
		partStack.setSelectedElement(placeholderC);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		assertNull(partB.getObject());
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(partA);
		partService.hidePart(partA);
		assertEquals(partC, partService.getActivePart());
	}
	public void testHidePart_ActivationHistory19() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPart partD = BasicFactoryImpl.eINSTANCE.createPart();
		window.getSharedElements().add(partD);
		MPerspectiveStack perspectiveStack = AdvancedFactoryImpl.eINSTANCE
				.createPerspectiveStack();
		window.getChildren().add(perspectiveStack);
		window.setSelectedElement(perspectiveStack);
		MPerspective perspectiveA = AdvancedFactoryImpl.eINSTANCE