Bug 71354 [painting] IAE in StyledText.getBidiSegments upon revert
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaSourceViewer.java
* The preference store.
	 * 
	 * @since 3.0
	 */
	private IPreferenceStore fPreferenceStore;
	/**
	 * Is this source viewer configured?
	 * 
	 * @since 3.0
	 */
	private boolean fIsConfigured;
	/**
	 * The backspace manager of this viewer.
	 * 
	 * @since 3.0
	 */
	private SmartBackspaceManager fBackspaceManager;
	
	public JavaSourceViewer(Composite parent, IVerticalRuler verticalRuler, IOverviewRuler overviewRuler, boolean showAnnotationsOverview, int styles, IPreferenceStore store) {
		super(parent, verticalRuler, overviewRuler, showAnnotationsOverview, styles);
		setPreferenceStore(store);
	}
	/*
	 * @see org.eclipse.jface.text.source.SourceViewer#createFormattingContext()
	 * @since 3.0
	 */
	public IFormattingContext createFormattingContext() {
		
		
		IFormattingContext context= new CommentFormattingContext();