Bug 1768317 - Make `InsertTextTransaction::GetData()` returns reference of its `mStringToInsert` r=m_kato

Differential Revision: https://phabricator.services.mozilla.com/D179521

editor/libeditor/InsertTextTransaction.cpp

@@ -157,9 +157,7 @@ NS_IMETHODIMP InsertTextTransaction::Merge(nsITransaction* aOtherTransaction,
     return NS_OK;
   }
 
-  nsAutoString otherData;
+  mStringToInsert += otherInsertTextTransaction->GetData();
-  otherInsertTextTransaction->GetData(otherData);
-  mStringToInsert += otherData;
   *aDidMerge = true;
   MOZ_LOG(GetLogModule(), LogLevel::Debug,
           ("%p InsertTextTransaction::%s(aOtherTransaction=%p) returned true",
@@ -169,12 +167,8 @@ NS_IMETHODIMP InsertTextTransaction::Merge(nsITransaction* aOtherTransaction,
 
 /* ============ private methods ================== */
 
-void InsertTextTransaction::GetData(nsString& aResult) {
-  aResult = mStringToInsert;
-}
-
 bool InsertTextTransaction::IsSequentialInsert(
-    InsertTextTransaction& aOtherTransaction) {
+    InsertTextTransaction& aOtherTransaction) const {
   return aOtherTransaction.mTextNode == mTextNode &&
          aOtherTransaction.mOffset == mOffset + mStringToInsert.Length();
 }

editor/libeditor/InsertTextTransaction.h

@@ -56,7 +56,7 @@ class InsertTextTransaction final : public EditTransactionBase {
   /**
    * Return the string data associated with this transaction.
    */
-  void GetData(nsString& aResult);
+  const nsString& GetData() const { return mStringToInsert; }
 
   template <typename EditorDOMPointType>
   EditorDOMPointType SuggestPointToPutCaret() const {
@@ -73,7 +73,7 @@ class InsertTextTransaction final : public EditTransactionBase {
   virtual ~InsertTextTransaction() = default;
 
   // Return true if aOtherTransaction immediately follows this transaction.
-  bool IsSequentialInsert(InsertTextTransaction& aOtherTrasaction);
+  bool IsSequentialInsert(InsertTextTransaction& aOtherTransaction) const;
 
   // The Text node to operate upon.
   RefPtr<dom::Text> mTextNode;