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/ClipboardOperationAction.java
fOperationTarget.doOperation(fOperationCode);
		
		if (clipboardData != null) {
			Clipboard clipboard= new Clipboard(getDisplay());
			try {
				
				Object textData= clipboard.getContents(TextTransfer.getInstance());
				Object rtfData= clipboard.getContents(RTFTransfer.getInstance());
				
				ArrayList datas= new ArrayList(3);
				ArrayList transfers= new ArrayList(3);
				if (textData != null) {
					datas.add(textData);
					transfers.add(TextTransfer.getInstance());
				}
				if (rtfData != null) {
					datas.add(rtfData);
					transfers.add(RTFTransfer.getInstance());
				}
				
				/*
				 * Don't add if we didn't get any data from the clipboard
				 * see: https://bugs.eclipse.org/bugs/show_bug.cgi?id=70077
				 */
				if (datas.isEmpty())
					return;
				datas.add(clipboardData);
				transfers.add(fgTransferInstance);