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
getEngine().createGui(window);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		MPart part = partService.showPart("partId", PartState.ACTIVATE);
		MElementContainer<?> parent = part.getParent();
		while (parent != null) {
			if (parent == perspectiveA) {
				break;
			} else if (parent == perspectiveB) {
				fail("Parent should not have been perspectiveB");
			}
			parent = parent.getParent();
		}
		assertNotNull(parent);
		perspectiveStack.setSelectedElement(perspectiveB);
		perspectiveB.getContext().activate();
		MPart part2 = partService.showPart("partId", PartState.ACTIVATE);
		parent = part2.getParent();
		while (parent != null) {
			if (parent == perspectiveB) {
				break;
			} else if (parent == perspectiveA) {
				fail("Parent should not have been perspectiveA");
			}
			parent = parent.getParent();
		}
		assertNotNull(parent);
		assertFalse(part == part2);
	}
	private void testShowPart_Part(PartState partState) {