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 the set of projects that contain the given set of resources.
	 * 
	 * @param resources
	 * @return
	 */
	static IProject[] getProjects(IResource[] resources) {
		if (resources == null) {
			return new IProject[0];
		}
		Collection projects = getProjectsAsCollection(resources);
		return (IProject[]) projects.toArray(new IProject[projects.size()]);
	}
	/**
	 * Return the projects for the elements.
	 * 
	 * @param elements
	 *            collection of IResource or IResourceMapping
	 * @return Collection of IProject
	 */
	static Collection getProjectsAsCollection(Object[] elements) {
		HashSet projects = new HashSet();
		for (int idx = 0; idx < elements.length; idx++) {
			if (elements[idx] instanceof IResource) {
				projects.add(((IResource) elements[idx]).getProject());
			} else {
				IProject[] mappingProjects = (((ResourceMapping) elements[idx])
						.getProjects());