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.SWTPartFactory#processContents
	 * (org.eclipse.e4.ui.model.application.MPart)
	 */
	@Override
	public void processContents(MElementContainer<MUIElement> me) {
		if (!(((MUIElement) me) instanceof MTrimBar))
			return;
		super.processContents(me);
		IEclipseContext ctx = getContext(me);
		ExpressionContext eContext = new ExpressionContext(ctx);
		MElementContainer<?> trimObj = me;
		MTrimBar trimModel = (MTrimBar) trimObj;
		ArrayList<MTrimContribution> toContribute = new ArrayList<MTrimContribution>();
		ContributionsAnalyzer.gatherTrimContributions(trimModel,
				application.getTrimContributions(), trimModel.getElementId(),
				toContribute, eContext);
		addTrimContributions(trimModel, toContribute, ctx, eContext);
	}
	private void addTrimContributions(final MTrimBar trimModel,
			ArrayList<MTrimContribution> toContribute, IEclipseContext ctx,
			final ExpressionContext eContext) {
		HashSet<String> existingToolbarIds = new HashSet<String>();
		for (MTrimElement item : trimModel.getChildren()) {
			String id = item.getElementId();
			if (item instanceof MToolBar && id != null) {
				existingToolbarIds.add(id);
			}