Bug 327964 EPartService's hidePart may fail when trying to hide a shared part that's in a shared container
The placeholder retrieval code in the EPartService implementation doesn't go far down deep enough and actually stops at the shared container level. This causes the placeholder of the shared part to not be found.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
assertEquals(part, partService.getActivePart());
	}
	public void testShowPart_Id_PartAlreadyShown_ACTIVATE() {
		testShowPart_Id_PartAlreadyShown(PartState.ACTIVATE);
	}
	public void testShowPart_Id_PartAlreadyShown_CREATE() {
		testShowPart_Id_PartAlreadyShown(PartState.CREATE);
	}
	public void testShowPart_Id_PartAlreadyShown_VISIBLE() {
		testShowPart_Id_PartAlreadyShown(PartState.VISIBLE);
	}
	private void testShowPart_Id_IncorrectDescriptor(PartState partState) {
		MApplication application = createApplication(1, new String[1][0]);
		MWindow window = application.getChildren().get(0);
		MPartDescriptor partDescriptor = org.eclipse.e4.ui.model.application.descriptor.basic.impl.BasicFactoryImpl.eINSTANCE
				.createPartDescriptor();
		partDescriptor.setElementId("partId");
		application.getDescriptors().add(partDescriptor);
		getEngine().createGui(window);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		assertNull(partService.showPart("partId2", partState));
	}
	public void testShowPart_Id_IncorrectDescriptor_ACTIVATE() {
		testShowPart_Id_IncorrectDescriptor(PartState.ACTIVATE);
	}
	public void testShowPart_Id_IncorrectDescriptor_VISIBLE() {
		testShowPart_Id_IncorrectDescriptor(PartState.VISIBLE);
	}
	public void testShowPart_Id_IncorrectDescriptor_CREATE() {