Bug 127289 [Markers] SystemFilter and group selection state not preserved
We are not preserving the selection state of the system filters or which group is selected.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerFilter.java
/**
	 * Returns a set of strings representing the full pathnames to every
	 * resource directly or indirectly contained in the working set. A resource
	 * is in the working set iff its path name can be found in this set.
	 * 
	 * @return Set
	 */
	private Set getWorkingSetAsSetOfPaths() {
		if (cachedWorkingSet == null) {
			HashSet result = new HashSet();
			addResourcesAndChildren(result, getResourcesInWorkingSet());
			cachedWorkingSet = result;
		}
		return cachedWorkingSet;
	}
	/***************************************************************************
	 * Adds the paths of all resources in the given array to the given set.
	 */
	private void addResourcesAndChildren(HashSet result, IResource[] resources) {
		for (int idx = 0; idx < resources.length; idx++) {
			IResource currentResource = resources[idx];
			result.add(currentResource.getFullPath().toString());
			if (currentResource instanceof IContainer) {
				IContainer cont = (IContainer) currentResource;
				try {
					addResourcesAndChildren(result, cont.members());
				} catch (CoreException e) {
					
				}
			}