Bug 326177 EPartService's getActivePart() does not appear to work properly for an application with multiple windows
Based on the code in PartServiceCreationFunction, the EPartService implementation being returned when an application's context is queried seems to be a window-level EPartService implementation.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
getEngine().createGui(windowB);
		EPartService partServiceA = (EPartService) partFrontA.getContext().get(
				EPartService.class.getName());
		EPartService partServiceB = (EPartService) partFrontB.getContext().get(
				EPartService.class.getName());
		partServiceA.activate(partBackA);
		assertEquals(partBackA, partServiceA.getActivePart());
		assertFalse(partServiceA.isPartVisible(partFrontA));
		assertTrue(partServiceA.isPartVisible(partBackA));
		assertFalse(partServiceA.isPartVisible(partFrontB));
		assertFalse(partServiceA.isPartVisible(partBackB));
		partServiceA.activate(partBackB);
		assertEquals(partBackA, partServiceA.getActivePart());
		assertFalse(partServiceA.isPartVisible(partFrontA));
		assertTrue(partServiceA.isPartVisible(partBackA));
		assertFalse(partServiceA.isPartVisible(partFrontB));
		assertFalse(partServiceA.isPartVisible(partBackB));
		assertFalse(partServiceB.isPartVisible(partFrontA));
		assertFalse(partServiceB.isPartVisible(partBackA));
		assertTrue(partServiceB.isPartVisible(partFrontB));
		assertFalse(partServiceB.isPartVisible(partBackB));
		partServiceB.activate(partBackB);
		assertEquals(partBackB, partServiceB.getActivePart());
		assertFalse(partServiceB.isPartVisible(partFrontA));
		assertFalse(partServiceB.isPartVisible(partBackA));
		assertFalse(partServiceB.isPartVisible(partFrontB));
		assertTrue(partServiceB.isPartVisible(partBackB));
	}
	public void testActivate_partService_SelectedElement() {
		MApplication application = createApplication(new String[] {