Bug 258810 [Markers] Markers for the entire workspace show up when working set empty
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/MarkerFieldFilterGroup.java
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()]);
	}
	/**
	 * Return the value of the scope.
	 * 
	 * @return int
	 * @see #ON_ANY
	 * @see #ON_ANY_IN_SAME_CONTAINER
	 * @see #ON_SELECTED_AND_CHILDREN
	 * @see #ON_SELECTED_ONLY
	 * @see #ON_WORKING_SET
	 */
	public int getScope() {
		return scope;
	}