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
getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(partB);
		partService.switchPerspective(perspectiveB);
		assertEquals(
				"partB is in both perspectives, active part should have been preserved",
				partB, partService.getActivePart());
		partService.hidePart(partB);
		assertEquals("Hiding partB should have caused partA to be activated",
				partA, partService.getActivePart());
		partService.switchPerspective(perspectiveA);
		assertEquals(
				"partB is the only part in perspectiveA, thus, it should be the active part",
				partB, partService.getActivePart());
		partService.switchPerspective(perspectiveB);
		assertEquals(
				"partA should be the only part that's being shown in perspectiveB, thus, it should be the active part",
				partA, partService.getActivePart());
	}
	/**
	 * Test to ensure that switching perspectives doesn't cause a hidden shared
	 * part to be displayed again.
	 */
	public void testHidePart_ActivationHistory16C() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPart partA = BasicFactoryImpl.eINSTANCE.createPart();