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.hidePart(part, force);
		assertEquals(perspectiveContext1, partContext.getParent());
		assertEquals(partContext, perspectiveContext1.getActiveChild());
		assertNull(
				"perspective2 doesn't have any parts, it should not have an active child context",
				perspectiveContext2.getActiveChild());
	}
	public void testHidePart_Bug332163_True() {
		testHidePart_Bug332163(true);
	}
	public void testHidePart_Bug332163_False() {
		testHidePart_Bug332163(false);
	}
	public void testHidePart_ActivationHistory01() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);
		MPartStack stackA = BasicFactoryImpl.eINSTANCE.createPartStack();
		window.getChildren().add(stackA);
		window.setSelectedElement(stackA);
		MPartStack stackB = BasicFactoryImpl.eINSTANCE.createPartStack();
		window.getChildren().add(stackB);
		MPart partA = BasicFactoryImpl.eINSTANCE.createPart();
		stackA.getChildren().add(partA);
		stackA.setSelectedElement(partA);
		MPart partB1 = BasicFactoryImpl.eINSTANCE.createPart();
		stackB.getChildren().add(partB1);
		stackB.setSelectedElement(partB1);