modifying the contents of a PasteOperation in Flex 4 - apache-flex

Question

I need to capture and modify the contents of a paste operation in my Flex 4 application. I am listening for the TextOperation.CHANGING event, pulling out the PasteOperation, and setting its textScrap property. Everything seems to be working, except that after I modify the textScrap, a newline character is added to the paste. I have created some sample code that illustrates the simplest version of the problem. I am not actually changing the copy, I am grabbing the existing textScrap's textFlow, creating a new TextScrap with it, and setting it on the PasteOperation. I did this to rule out TextFlow creation as the problem:
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600">
<fx:Declarations>
<!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
<fx:Script>
<![CDATA[
import flash.desktop.Clipboard;
import flash.desktop.ClipboardFormats;
import flashx.textLayout.edit.TextScrap;
import flashx.textLayout.elements.TextFlow;
import flashx.textLayout.operations.PasteOperation;
import flashx.textLayout.tlf_internal;
import spark.events.TextOperationEvent;
use namespace tlf_internal;
protected function textArea_changingHandler(event:TextOperationEvent):void
{
if (event.operation is PasteOperation)
{
var pasteOp:PasteOperation = event.operation as PasteOperation;
pasteOp.textScrap = new TextScrap(pasteOp.textScrap.textFlow);
}
}
]]>
</fx:Script>
<s:TextArea id="textArea" changing="textArea_changingHandler(event)"/>
</s:Application>
Thanks in advance,
Gerry

Answer 1

This appears to be a bug that Adobe fixed in sdk 4.6.
As some additional information, replacing the pasteOp.textScrap line above with:
pasteOp.textScrap = pasteOp.textScrap.clone() used to throw a null pointer exception, and in 4.6 that works too now.
Also, this bug only appeared when the textarea / textinput was empty. if there was something already in there, everything worked as expected.