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
partService.activate(partA);
		assertEquals(partA, partService.getActivePart());
		partService.switchPerspective(perspectiveB);
		assertEquals(partB, partService.getActivePart());
		partService.activate(partC);
		assertEquals(partC, partService.getActivePart());
		partService.switchPerspective(perspectiveA);
		assertEquals(partA, partService.getActivePart());
		partService.hidePart(partB, force);
		assertFalse(placeholderB1.isToBeRendered());
	}
	public void testHidePart_Bug327917_True() {
		testHidePart_Bug327917(true);
	}
	public void testHidePart_Bug327917_False() {
		testHidePart_Bug327917(false);
	}
	private void testHidePart_Bug327964(boolean force) {
		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 part = BasicFactoryImpl.eINSTANCE.createPart();
		window.getSharedElements().add(part);
		MPerspectiveStack perspectiveStack = AdvancedFactoryImpl.eINSTANCE
				.createPerspectiveStack();
		window.getChildren().add(perspectiveStack);