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
application.setSelectedElement(window);
		MArea area = AdvancedFactoryImpl.eINSTANCE.createArea();
		window.getSharedElements().add(area);
		MPart partA = BasicFactoryImpl.eINSTANCE.createPart();
		area.getChildren().add(partA);
		area.setSelectedElement(partA);
		MPerspectiveStack perspectiveStack = AdvancedFactoryImpl.eINSTANCE
				.createPerspectiveStack();
		window.getChildren().add(perspectiveStack);
		window.setSelectedElement(perspectiveStack);
		MPerspective perspectiveA = AdvancedFactoryImpl.eINSTANCE
				.createPerspective();
		perspectiveStack.getChildren().add(perspectiveA);
		perspectiveStack.setSelectedElement(perspectiveA);
		MPlaceholder areaPlaceholderA = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		areaPlaceholderA.setRef(area);
		area.setCurSharedRef(areaPlaceholderA);
		perspectiveA.getChildren().add(areaPlaceholderA);
		perspectiveA.setSelectedElement(areaPlaceholderA);
		MPartStack partStack = BasicFactoryImpl.eINSTANCE.createPartStack();
		perspectiveA.getChildren().add(partStack);
		MPart partB = BasicFactoryImpl.eINSTANCE.createPart();
		partStack.getChildren().add(partB);
		MPart partC = BasicFactoryImpl.eINSTANCE.createPart();
		partStack.getChildren().add(partC);
		partStack.setSelectedElement(partC);
		MPerspective perspectiveB = AdvancedFactoryImpl.eINSTANCE
				.createPerspective();
		perspectiveStack.getChildren().add(perspectiveB);