Bug 326087 StackRenderer arbitrarily changes selected element when MPartStack is being unrendered
1. Open two files. 2. Activate the editor in the back. 3. Restart 4. The file in the wrong is active now. :O
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/StackRenderer.java
cti.setText(getLabel(part, newName));
		} else if (UIEvents.UILabel.ICONURI.equals(attName)) {
			cti.setImage(getImage(part));
		} else if (UIEvents.UILabel.TOOLTIP.equals(attName)) {
			String newTTip = (String) newValue;
			cti.setToolTipText(newTTip);
		} else if (UIEvents.Dirtyable.DIRTY.equals(attName)) {
			Boolean dirtyState = (Boolean) newValue;
			String text = cti.getText();
			boolean hasAsterisk = text.charAt(0) == '*';
			if (dirtyState.booleanValue()) {
				if (!hasAsterisk) {
					cti.setText('*' + text);
				}
			} else if (hasAsterisk) {
				cti.setText(text.substring(1));
			}
		}
	}
	@PreDestroy
	public void contextDisposed() {
		super.contextDisposed(eventBroker);
		eventBroker.unsubscribe(itemUpdater);
		eventBroker.unsubscribe(dirtyUpdater);
	}
	private String getLabel(MUILabel itemPart, String newName) {
		if (newName == null) {
			newName = ""; 
		}
		if (itemPart instanceof MDirtyable && ((MDirtyable) itemPart).isDirty()) {