Bug 337002 EPartService leaks previously active part
A reference is kept to the previously active part. This is unnecessary. We only need it to fire events. After the deactivation events have been fired, we should no longer need to keep it lying around.
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());
		Collection<MPart> parts = partService.getParts();
		assertNotNull(parts);
		assertEquals(2, parts.size());
		assertTrue(parts.containsAll(partStack.getChildren()));
	}
	public void testGetParts_TwoWindows() {
		MApplication application = createApplication(new String[] { "partId",
				"partId2" }, new String[] { "partIA", "partIdB", "partIdC" });
		MWindow windowA = application.getChildren().get(0);
		MWindow windowB = application.getChildren().get(1);
		getEngine().createGui(windowA);
		getEngine().createGui(windowB);
		EPartService partServiceA = (EPartService) windowA.getContext().get(
				EPartService.class.getName());
		EPartService partServiceB = (EPartService) windowB.getContext().get(
				EPartService.class.getName());
		MPartStack partStackA = (MPartStack) windowA.getChildren().get(0);
		MPartStack partStackB = (MPartStack) windowB.getChildren().get(0);
		Collection<MPart> partsA = partServiceA.getParts();
		Collection<MPart> partsB = partServiceB.getParts();
		assertNotNull(partsA);
		assertEquals(2, partsA.size());
		assertTrue(partsA.containsAll(partStackA.getChildren()));
		assertNotNull(partsB);
		assertEquals(3, partsB.size());
		assertTrue(partsB.containsAll(partStackB.getChildren()));
		for (MPart partA : partsA) {