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
}
		});
		
		fViewer.addOpenListener(new IOpenListener() {
			public void open(OpenEvent event) {
				fActionSet.handleOpen(event);
			}
		});
		IStatusLineManager slManager= getViewSite().getActionBars().getStatusLineManager();
		fViewer.addSelectionChangedListener(new StatusBarUpdater(slManager));
		fViewer.addTreeListener(fExpansionListener);
	
		if (fMemento != null)
			restoreUIState(fMemento);
		fMemento= null;
	
		 
		JavaUIHelp.setHelp(fViewer, IJavaHelpContextIds.PACKAGES_VIEW);
		
		fillActionBars();
		updateTitle();
		
		fFilterUpdater= new FilterUpdater(fViewer);
		ResourcesPlugin.getWorkspace().addResourceChangeListener(fFilterUpdater);
		
		stats.endRun();
	}
	private void initFrameActions() {
		fActionSet.getUpAction().update();
		fActionSet.getBackAction().update();