--- a/editor/libeditor/HTMLEditRules.cpp
+++ b/editor/libeditor/HTMLEditRules.cpp
@@ -10198,16 +10198,19 @@ nsresult
 HTMLEditRules::DidAbsolutePosition()
 {
   MOZ_ASSERT(IsEditorDataAvailable());
 
   if (!mNewBlock) {
     return NS_OK;
   }
   nsresult rv = HTMLEditorRef().SetPositionToAbsoluteOrStatic(*mNewBlock, true);
+  if (NS_WARN_IF(!CanHandleEditAction())) {
+    return NS_ERROR_EDITOR_DESTROYED;
+  }
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   return NS_OK;
 }
 
 nsresult
 HTMLEditRules::WillRemoveAbsolutePosition(bool* aCancel,

--- a/editor/libeditor/HTMLEditRules.h
+++ b/editor/libeditor/HTMLEditRules.h
@@ -286,17 +286,26 @@ protected:
   WillRelativeChangeZIndex(int32_t aChange, bool* aCancel, bool* aHandled);
 
   nsresult WillMakeDefListItem(const nsAString* aBlockType, bool aEntireList,
                                bool* aCancel, bool* aHandled);
   nsresult WillMakeBasicBlock(const nsAString& aBlockType,
                               bool* aCancel, bool* aHandled);
   nsresult MakeBasicBlock(nsAtom& aBlockType);
   nsresult DidMakeBasicBlock(RulesInfo* aInfo, nsresult aResult);
-  nsresult DidAbsolutePosition();
+
+  /**
+   * Called if nobody handles the edit action to make an element absolute
+   * positioned.
+   * This method actually changes the element which is computed by
+   * WillAbsolutePosition() to absolute positioned.
+   * Therefore, this might cause destroying the HTML editor.
+   */
+  MOZ_MUST_USE nsresult DidAbsolutePosition();
+
   nsresult AlignInnerBlocks(nsINode& aNode, const nsAString& aAlignType);
   nsresult AlignBlockContents(nsINode& aNode, const nsAString& aAlignType);
   nsresult AppendInnerFormatNodes(nsTArray<OwningNonNull<nsINode>>& aArray,
                                   nsINode* aNode);
   nsresult GetFormatString(nsINode* aNode, nsAString &outFormat);
   enum class Lists { no, yes };
   enum class Tables { no, yes };
   void GetInnerContent(nsINode& aNode,