Bug 338816 Resetting a perspective with multiple minimized stacks causes 'widget is disposed' errors
Found when testing the new min/max work... This is a bad one; open a fresh session, maximize the editor area and then reset the perspective...whamo ! The workbench is left in an unusable state...
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/TrimBarRenderer.java
* (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.e4.ui.workbench.renderers.swt.SWTPartRenderer#init(org.eclipse
	 * .e4.core.contexts.IEclipseContext)
	 */
	@Override
	public void init(IEclipseContext context) {
		super.init(context);
		application = context.get(MApplication.class);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.e4.ui.workbench.renderers.PartFactory#createWidget(org.eclipse
	 * .e4.ui.model.application.MPart)
	 */
	@Override
	public Object createWidget(MUIElement element, Object parent) {
		if (!(element instanceof MTrimBar) || !(parent instanceof Composite))
			return null;
		Composite parentComp = (Composite) parent;
		if (!(parentComp.getLayout() instanceof TrimmedPartLayout))
			return null;
		final MTrimBar trimModel = (MTrimBar) element;
		TrimmedPartLayout tpl = (TrimmedPartLayout) parentComp.getLayout();
		Composite result = null;
		switch (trimModel.getSide().getValue()) {
		case SideValue.TOP_VALUE: