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
fEditorSelectionChangedListener= null;
		}
				
		super.dispose();
	}
	
	protected void createActions() {
		super.createActions();
		
		ActionGroup oeg, ovg, jsg, sg;
		fActionGroups= new CompositeActionGroup(new ActionGroup[] {
			oeg= new OpenEditorActionGroup(this),
			sg= new ShowActionGroup(this),
			ovg= new OpenViewActionGroup(this),
			jsg= new JavaSearchActionGroup(this)
		});
		fContextMenuGroup= new CompositeActionGroup(new ActionGroup[] {oeg, ovg, sg, jsg});
		
		fFoldingGroup= new FoldingActionGroup(this, getViewer());
		
		ResourceAction resAction= new TextOperationAction(JavaEditorMessages.getResourceBundle(), "ShowJavaDoc.", this, ISourceViewer.INFORMATION, true); 
		resAction= new InformationDispatchAction(JavaEditorMessages.getResourceBundle(), "ShowJavaDoc.", (TextOperationAction) resAction); 
		resAction.setActionDefinitionId(IJavaEditorActionDefinitionIds.SHOW_JAVADOC);
		setAction("ShowJavaDoc", resAction); 
		WorkbenchHelp.setHelp(resAction, IJavaHelpContextIds.SHOW_JAVADOC_ACTION);
		
		Action action= new GotoMatchingBracketAction(this);
		action.setActionDefinitionId(IJavaEditorActionDefinitionIds.GOTO_MATCHING_BRACKET);				
		setAction(GotoMatchingBracketAction.GOTO_MATCHING_BRACKET, action);