Deleteing/Replacing Surrogate-Pair string causes RTE in TLF

Case 1
Step 1. Input "𣘺" to s:TextInput
Step 2. delete string of [Step 1] by DELETE/BACKSPACE key
An RTE happens like below

RangeError: Invalid splitting of a surrogate pair
at flashx.textLayout.elements::SpanElement/replaceText()
at flashx.textLayout.edit::TextFlowEdit$/deleteRangeInternal()
at flashx.textLayout.edit::TextFlowEdit$/deleteRangeInternal()
at flashx.textLayout.edit::TextFlowEdit$/http://ns.adobe.com/textLayout/internal/2008::deleteRange()
at flashx.textLayout.edit::ModelEdit$/deleteText()
at flashx.textLayout.operations::DeleteTextOperation/doOperation()
at flashx.textLayout.edit::EditManager/doInternal()
at flashx.textLayout.edit::EditManager/doOperation()
at flashx.textLayout.edit::EditManager/deletePreviousCharacter()
at flashx.textLayout.edit::EditManager/keyDownHandler()
at flashx.textLayout.container::ContainerController/keyDownHandler()
at flashx.textLayout.container::TextContainerManager/keyDownHandler()
at spark.components.supportClasses::RichEditableTextContainerManager/keyDownHandler()

Case 2
Step 1. Input "𣘺" to s:TextInput
Step 2. copy this string : "A"
Step 3. select string of [Step 1]
Step 4. press [Ctrl + V]
Two RTE happen like below

RangeError: Invalid splitting of a surrogate pair
at flashx.textLayout.elements::SpanElement/replaceText()
at flashx.textLayout.edit::TextFlowEdit$/deleteRangeInternal()
at flashx.textLayout.edit::TextFlowEdit$/deleteRangeInternal()
at flashx.textLayout.edit::TextFlowEdit$/http://ns.adobe.com/textLayout/internal/2008::deleteRange()
at flashx.textLayout.edit::ModelEdit$/deleteText()
at flashx.textLayout.operations::DeleteTextOperation/doOperation()
at flashx.textLayout.operations::InsertTextOperation/doDelete()
at flashx.textLayout.operations::InsertTextOperation/doInternal()
at flashx.textLayout.operations::InsertTextOperation/doOperation()
at flashx.textLayout.edit::EditManager/doInternal()
at flashx.textLayout.edit::EditManager/doOperation()
at flashx.textLayout.edit::EditManager/flushPendingOperations()
at flashx.textLayout.edit::EditManager/insertText()
at spark.components::RichEditableText/handlePasteOperation()
at spark.components::RichEditableText/textContainerManager_flowOperationEndHandler()
at flash.events::EventDispatcher/dispatchEvent()
at flashx.textLayout.container::TextContainerManager/dispatchEvent()
at flash.events::EventDispatcher/dispatchEvent()
at flashx.textLayout.elements::TextFlow/dispatchEvent()
at flashx.textLayout.edit::EditManager/doInternal()
at flashx.textLayout.edit::EditManager/doOperation()
at flashx.textLayout.edit::EditManager/pasteTextScrap()
at flashx.textLayout.edit::EditManager/editHandler()
at flashx.textLayout.container::ContainerController/editHandler()
at flashx.textLayout.container::TextContainerManager/editHandler()
at flash.desktop::NativeApplication/_onKeyDownBubble()

RangeError: Invalid splitting of a surrogate pair
at flashx.textLayout.elements::SpanElement/replaceText()
at flashx.textLayout.edit::TextFlowEdit$/deleteRangeInternal()
at flashx.textLayout.edit::TextFlowEdit$/deleteRangeInternal()
at flashx.textLayout.edit::TextFlowEdit$/http://ns.adobe.com/textLayout/internal/2008::deleteRange()
at flashx.textLayout.edit::ModelEdit$/deleteText()
at flashx.textLayout.operations::DeleteTextOperation/doOperation()
at flashx.textLayout.operations::PasteOperation/doOperation()
at flashx.textLayout.edit::EditManager/doInternal()
at flashx.textLayout.edit::EditManager/doOperation()
at flashx.textLayout.edit::EditManager/pasteTextScrap()
at flashx.textLayout.edit::EditManager/editHandler()
at flashx.textLayout.container::ContainerController/editHandler()
at flashx.textLayout.container::TextContainerManager/editHandler()
at flash.desktop::NativeApplication/_onKeyDownBubble()