Bug 167170 [Markers] Need to check for duplicate filter names
M3 It is currently possible to enter duplicate filter names
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/DialogMarkerFilter.java
private Button button;
		private Button selectButton;
		/**
		 * Creates the working set filter selection widgets.
		 * 
		 * @param parent
		 *            the parent composite of the working set widgets
		 */
		WorkingSetGroup(Composite parent) {
			
			button = createRadioButton(parent,
					MarkerMessages.filtersDialog_noWorkingSet);
			GridData data = new GridData(GridData.FILL_HORIZONTAL);
			button.setLayoutData(data);
			Composite composite = new Composite(parent, SWT.NONE);
			composite.setFont(parent.getFont());
			GridLayout layout = new GridLayout();
			Button radio = new Button(parent, SWT.RADIO);
			layout.marginWidth = radio.computeSize(SWT.DEFAULT, SWT.DEFAULT).x;