Bug 322403 Showing a shared part with PartState.VISIBLE may not work correctly due to incorrect parent comparisons
We check the parents of the active part against the part-to-be-shown to determine how to respond when PartState.VISIBLE is used but the check is always 'true' for shared parts because getParent() returns 'null' for both parts. This is obviously wrong. We need to update the code to consider placeholders.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
window.getChildren().add(partStack);
			for (int j = 0; j < partIds[i].length; j++) {
				MPart part = BasicFactoryImpl.eINSTANCE.createPart();
				part.setElementId(partIds[i][j]);
				partStack.getChildren().add(part);
			}
		}
		initialize(applicationContext, application);
		return application;
	}
	private void initialize(IEclipseContext applicationContext,
			MApplication application) {
		application.setContext(applicationContext);
		applicationContext.set(MApplication.class.getName(), application);
		E4Workbench.processHierarchy(application);
		((Notifier) application).eAdapters().add(
				new UIEventPublisher(applicationContext));
		applicationContext.set(ISaveHandler.class.getName(),
				new ISaveHandler() {
					public Save[] promptToSave(Collection<MPart> saveablePart) {
						Save[] ret = new Save[saveablePart.size()];
						Arrays.fill(ret, ISaveHandler.Save.YES);
						return ret;
					}
					public Save promptToSave(MPart saveablePart) {
						return ISaveHandler.Save.YES;
					}
				});
	}
	class PartListener implements IPartListener {