Bug 81877 Package explorer forgets active working set [package explorer]
3.1 M4 1. open pkg explorer. 2. select a working set, pkg explorer updates and filters out projects. 3. close pkg explorer. 4. open package explorer again and the working set is no longer applied. This used to work.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
public void selectReveal(ISelection selection) {
		selectReveal(selection, 0);
	}
	
	private void selectReveal(final ISelection selection, final int count) {
		Control ctrl= getViewer().getControl();
		if (ctrl == null || ctrl.isDisposed())
			return;
		ISelection javaSelection= convertSelection(selection);
		fViewer.setSelection(javaSelection, true);
		PackageExplorerContentProvider provider= (PackageExplorerContentProvider)getViewer().getContentProvider();
		ISelection cs= fViewer.getSelection();
		
		
		
		
		if (count == 0 && provider.hasPendingChanges() && !javaSelection.equals(cs)) {
			ctrl.getDisplay().asyncExec(new Runnable() {
				public void run() {
					selectReveal(selection, count + 1);
				}
			});
		}
	}
	private ISelection convertSelection(ISelection s) {
		if (!(s instanceof IStructuredSelection))
			return s;
			
		Object[] elements= ((StructuredSelection)s).toArray();
		if (!containsResources(elements))