Bug 81740 Package explorer not correctly updated when deleting more than one project
M4 - create two projects X and XX - switch to workingset mode - put both into a working set - select both and delete them observe: one project is still rendered as a closed project.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/workingsets/JavaWorkingSetUpdater.java
fWorkingSet.setElements((IAdaptable[])fElements.toArray(new IAdaptable[fElements.size()]));
			}
		}
	}
	
	public JavaWorkingSetUpdater() {
		fWorkingSets= new ArrayList();
		JavaCore.addElementChangedListener(this);
	}
	
	/**
	 * {@inheritDoc}
	 */
	public void add(IWorkingSet workingSet) {
		checkElementExistence(workingSet);
		synchronized (fWorkingSets) {
			fWorkingSets.add(workingSet);
		}
	}
	/**
	 * {@inheritDoc}
	 */
	public boolean remove(IWorkingSet workingSet) {
		boolean result;
		synchronized(fWorkingSets) {
			result= fWorkingSets.remove(workingSet);
		}
		return result;
	}