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
}
		}
		if (unfiltered == null) {
			unfiltered = Collections.EMPTY_LIST;
		}
		return unfiltered;
	}
	/**
	 * 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.isEmpty()) {
			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()]);
	}