Bug 75711 AstProvider should not create AST if requested by SelectionListenerWithASTManager
3.1 M2 If SelectionListenerWithASTManager waits for an AST and the editor closes we should not create an AST for that one but return null instead.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
fLastMarkerTarget= marker;
		if (!fIsUpdatingAnnotationViews) {
		    super.gotoMarker(marker);
		}
	}
	
	/**
	 * Jumps to the next enabled annotation according to the given direction.
	 * An annotation type is enabled if it is configured to be in the
	 * Next/Previous tool bar drop down menu and if it is checked.
	 * 
	 * @param forward <code>true</code> if search direction is forward, <code>false</code> if backward
	 */
	public void gotoAnnotation(boolean forward) {
		ITextSelection selection= (ITextSelection) getSelectionProvider().getSelection();
		Position position= new Position(0, 0);
		if (false ) {
			getNextAnnotation(selection.getOffset(), selection.getLength(), forward, position);
			selectAndReveal(position.getOffset(), position.getLength());
		} else  {
			Annotation annotation= getNextAnnotation(selection.getOffset(), selection.getLength(), forward, position);
			setStatusLineErrorMessage(null);
			setStatusLineMessage(null);
			if (annotation != null) {
				updateAnnotationViews(annotation);
				selectAndReveal(position.getOffset(), position.getLength());
				setStatusLineMessage(annotation.getText());
			}
		}
	}