Bug 328339 Part activation history seems to ignore detached windows
1. Detach a view. 2. Drag another view into said detached window. 3. Activate the two views alternatively. 4. Close one of them. 5. A part in the workbench window is activated instead of the other view in the detached window.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
MPart partB = partService.showPart("partB",
				EPartService.PartState.VISIBLE);
		assertEquals(2, partStack.getChildren().size());
		assertEquals(
				"The part is in the same stack as the active part, so the active part should not have changed",
				partA, partService.getActivePart());
		assertNotNull("The shown part should have a context",
				partB.getContext());
		assertTrue(partService.isPartVisible(partA));
		assertFalse(partService.isPartVisible(partB));
	}
	public void testShowPart_Id_VISIBLE3() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		MPartDescriptor partDescriptor = org.eclipse.e4.ui.model.application.descriptor.basic.impl.BasicFactoryImpl.eINSTANCE
				.createPartDescriptor();
		partDescriptor.setElementId("partB");
		partDescriptor.setCategory("aCategory");
		application.getDescriptors().add(partDescriptor);
		MPartStack partStackA = BasicFactoryImpl.eINSTANCE.createPartStack();
		window.getChildren().add(partStackA);
		MPartStack partStackB = BasicFactoryImpl.eINSTANCE.createPartStack();
		partStackB.getTags().add("aCategory");
		window.getChildren().add(partStackB);
		MPart partA = BasicFactoryImpl.eINSTANCE.createPart();
		partA.setElementId("partA");
		partStackA.getChildren().add(partA);
		partStackA.setSelectedElement(partA);