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
setContentDescription(inputText);
			setTitleToolTip(getToolTipText(input));
		} 
	}
	
	/**
	 * Sets the decorator for the package explorer.
	 *
	 * @param decorator a label decorator or <code>null</code> for no decorations.
	 * @deprecated To be removed
	 */
	public void setLabelDecorator(ILabelDecorator decorator) {
	}
	
	/*
	 * @see IPropertyChangeListener#propertyChange(PropertyChangeEvent)
	 */
	public void propertyChange(PropertyChangeEvent event) {
		if (fViewer == null)
			return;
		
		boolean refreshViewer= false;
	
		if (PreferenceConstants.SHOW_CU_CHILDREN.equals(event.getProperty())) {
			fActionSet.updateActionBars(getViewSite().getActionBars());
			
			boolean showCUChildren= PreferenceConstants.getPreferenceStore().getBoolean(PreferenceConstants.SHOW_CU_CHILDREN);
			((StandardJavaElementContentProvider)fViewer.getContentProvider()).setProvideMembers(showCUChildren);
			
			refreshViewer= true;