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());
		partService.hidePart(part);
		assertFalse(part.isToBeRendered());
		assertEquals(tagged ? null : window, part.getParent());
	}
	public void testHidePart_Tagged_True() {
		testHidePart_Tagged(true);
	}
	public void testHidePart_Tagged_False() {
		testHidePart_Tagged(false);
	}
	public void testGetDirtyParts() {
		MApplication application = createApplication(1, new String[1][0]);
		MWindow window = application.getChildren().get(0);
		getEngine().createGui(window);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		Collection<MPart> dirtyParts = partService.getDirtyParts();
		assertNotNull(dirtyParts);
		assertEquals(0, dirtyParts.size());
	}
	public void testGetDirtyParts2() {
		MApplication application = createApplication("partId");
		MWindow window = application.getChildren().get(0);
		getEngine().createGui(window);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		Collection<MPart> dirtyParts = partService.getDirtyParts();