Bug 310908 [Markers] NPE thrown by markers job
I20100426-0852 I had one editor open in my window. It was maximized and opened on an external file. When I closed it, this NPE suddenly appeared. java.lang.NullPointerException at org.eclipse.ui.internal.views.markers.MarkerFieldFilterGroup.loadSettings(MarkerFieldFilterGroup.java:448) at org.eclipse.ui.internal.views.markers.MarkerContentGenerator.loadGroupWithID(MarkerContentGenerator.java:521) at org.eclipse.ui.internal.views.markers.MarkerContentGenerator.loadFilterSettings(MarkerContentGenerator.java:449) at org.eclipse.ui.internal.views.markers.MarkerContentGenerator.loadFiltersFrom(MarkerContentGenerator.java:467) at org.eclipse.ui.internal.views.markers.MarkerContentGenerator.loadFiltersPreference(MarkerContentGenerator.java:479) at org.eclipse.ui.internal.views.markers.MarkerContentGenerator.getAllFilters(MarkerContentGenerator.java:293) at org.eclipse.ui.internal.views.markers.MarkerContentGenerator.getEnabledFilters(MarkerContentGenerator.java:307) at org.eclipse.ui.internal.views.markers.MarkerContentGenerator.getResourcesForBuild(MarkerContentGenerator.java:904) at org.eclipse.ui.internal.views.markers.MarkerContentGenerator.gatherMarkers(MarkerContentGenerator.java:1004) at org.eclipse.ui.internal.views.markers.MarkerContentGenerator.generateMarkerEntries(MarkerContentGenerator.java:991) at org.eclipse.ui.internal.views.markers.MarkerUpdateJob.clean(MarkerUpdateJob.java:117) at org.eclipse.ui.internal.views.markers.MarkerUpdateJob.buildMarkers(MarkerUpdateJob.java:77) at org.eclipse.ui.internal.views.markers.MarkerUpdateJob.run(MarkerUpdateJob.java:57) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/MarkerFieldFilterGroup.java
* Return the resources in the working set. If it is empty then return the
	 * workspace root.
	 * 
	 * @return IResource[]
	 */
	IResource[] getResourcesInWorkingSet() {
		if (workingSet == null) {
			return new IResource[0];
		}
		
		if (workingSet.isAggregateWorkingSet()&&workingSet.isEmpty()){
			if(((AggregateWorkingSet) workingSet).getComponents().length==0)
				return new IResource[] { ResourcesPlugin.getWorkspace().getRoot()};
		}
		
		IAdaptable[] elements = workingSet.getElements();
		List result = new ArrayList(elements.length);
		for (int idx = 0; idx < elements.length; idx++) {
			IResource next = (IResource) elements[idx]
					.getAdapter(IResource.class);
			if (next != null) {
				result.add(next);
			}
		}
		return (IResource[]) result.toArray(new IResource[result.size()]);
	}
	/**
	 * Return the value of the scope.
	 * 
	 * @return int