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
partService.bringToTop(partB);
		assertEquals(
				"Bringing a part to top that's not in the same container as the active part shouldn't change the active part",
				partC, partService.getActivePart());
	}
	public void testBringToTop_Bug330508_04() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPart partA = BasicFactoryImpl.eINSTANCE.createPart();
		window.getSharedElements().add(partA);
		MPerspectiveStack perspectiveStack = AdvancedFactoryImpl.eINSTANCE
				.createPerspectiveStack();
		window.getChildren().add(perspectiveStack);
		window.setSelectedElement(perspectiveStack);
		MPerspective perspective = AdvancedFactoryImpl.eINSTANCE
				.createPerspective();
		perspectiveStack.getChildren().add(perspective);
		perspectiveStack.setSelectedElement(perspective);
		MPartStack partStack = BasicFactoryImpl.eINSTANCE.createPartStack();
		perspective.getChildren().add(partStack);
		perspective.setSelectedElement(partStack);
		MPlaceholder placeholderA = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		placeholderA.setRef(partA);
		partA.setCurSharedRef(placeholderA);
		partStack.getChildren().add(placeholderA);
		partStack.setSelectedElement(placeholderA);