Bug 328946 Part activation history may return incorrect candidate if no placeholders could be found in a perspective
1. Window > Open Perspective > Other... > CVS Repository Exploring 2. Hide the 'CVS Repositories' view. 3. The 'History' view should become active, it is not.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
MPart sharedPart = (MPart) placeholder.getRef();
		sharedPart.setCurSharedRef(placeholder);
		placeholder.setToBeRendered(false);
		sharedPart.setToBeRendered(false);
		perspective.getChildren().add(placeholder);
		partService.showPart(sharedPart, partState);
		assertNotNull(perspective.getSelectedElement());
		assertEquals(placeholder, perspective.getSelectedElement());
	}
	public void testShowPart_Bug322368_Placeholder_ACTIVATE() {
		testShowPart_Bug322368_Placeholder(PartState.ACTIVATE);
	}
	public void testShowPart_Bug322368_Placeholder_VISIBLE() {
		testShowPart_Bug322368_Placeholder(PartState.VISIBLE);
	}
	public void testShowPart_Bug322368_Placeholder_CREATE() {
		testShowPart_Bug322368_Placeholder(PartState.CREATE);
	}
	public void testShowPart_Bug322403_A() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MPartDescriptor partDescriptor = org.eclipse.e4.ui.model.application.descriptor.basic.impl.BasicFactoryImpl.eINSTANCE
				.createPartDescriptor();
		partDescriptor.setElementId("partId");
		partDescriptor.setAllowMultiple(true);
		application.getDescriptors().add(partDescriptor);
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPerspectiveStack perspectiveStack = AdvancedFactoryImpl.eINSTANCE