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());
		MPart shownPart = partService.showPart("partId", partState);
		assertNotNull(shownPart);
		assertEquals(part, shownPart);
	}
	public void testShowPart_Id_MultipleExists_TrueACTIVATE() {
		testShowPart_Id_MultipleExists(true, PartState.ACTIVATE);
	}
	public void testShowPart_Id_MultipleExists_FalseACTIVATE() {
		testShowPart_Id_MultipleExists(false, PartState.ACTIVATE);
	}
	public void testShowPart_Id_MultipleExists_TrueVISIBLE() {
		testShowPart_Id_MultipleExists(true, PartState.VISIBLE);
	}
	public void testShowPart_Id_MultipleExists_FalseVISIBLE() {
		testShowPart_Id_MultipleExists(false, PartState.VISIBLE);
	}
	public void testShowPart_Id_MultipleExists_TrueCREATE() {
		testShowPart_Id_MultipleExists(true, PartState.CREATE);
	}
	public void testShowPart_Id_MultipleExists_FalseCREATE() {
		testShowPart_Id_MultipleExists(false, PartState.CREATE);
	}
	public void testShowPart_Id_PartInInactivePerspective() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);