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
super.editorContextMenuAboutToShow(menu);
		menu.appendToGroup(ITextEditorActionConstants.GROUP_UNDO, new Separator(IContextMenuConstants.GROUP_OPEN));	
		menu.insertAfter(IContextMenuConstants.GROUP_OPEN, new GroupMarker(IContextMenuConstants.GROUP_SHOW));	
		
		ActionContext context= new ActionContext(getSelectionProvider().getSelection());
		fContextMenuGroup.setContext(context);
		fContextMenuGroup.fillContextMenu(menu);
		fContextMenuGroup.setContext(null);
	}			
	
	/**
	 * Creates the outline page used with this editor.
	 * 
	 * @return the created Java outline page
	 */
	protected JavaOutlinePage createOutlinePage() {
		JavaOutlinePage page= new JavaOutlinePage(fOutlinerContextMenuId, this);
		fOutlineSelectionChangedListener.install(page);
		setOutlinePageInput(page, getEditorInput());
		return page;
	}
	
	/**
	 * Informs the editor that its outliner has been closed.
	 */
	public void outlinePageClosed() {
		if (fOutlinePage != null) {
			fOutlineSelectionChangedListener.uninstall(fOutlinePage);
			fOutlinePage= null;
			resetHighlightRange();