Bug 119076 [Markers] ArrayStoreException when multiselection in Problems view includes category
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/ProblemView.java
protected ViewerSorter buildSorter() {
		TableSorter sorter = new TableSorter(getSortingFields(),
				getDefaultPriorities(), getDefaultDirections());
		if (isHierarchalMode())
			return new CategorySorter(sorter);
		return sorter;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.views.markers.internal.TableView#getVisibleFields()
	 */
	protected IField[] getVisibleFields() {
		return VISIBLE_FIELDS;
	}
	void updateTitle() {
		MarkerList visibleMarkers = getVisibleMarkers();
		String breakdown = formatSummaryBreakDown(visibleMarkers);
		int filteredCount = visibleMarkers.getItemCount();
		int totalCount = getTotalMarkers();
		if (filteredCount != totalCount)
			breakdown = NLS.bind(MarkerMessages.problem_filter_matchedMessage,
					new Object[] { breakdown, new Integer(filteredCount),
							new Integer(totalCount) });
		setContentDescription(breakdown);
	}
	private String formatSummaryBreakDown(MarkerList visibleMarkers) {
		return MessageFormat.format(
				MarkerMessages.problem_statusSummaryBreakdown, new Object[] {
						new Integer(visibleMarkers.getErrors()),