diff -r 000000000000 -r 6474c204b198 editor/txmgr/src/nsTransactionItem.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/editor/txmgr/src/nsTransactionItem.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,388 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/mozalloc.h"
+#include "nsAutoPtr.h"
+#include "nsCOMPtr.h"
+#include "nsDebug.h"
+#include "nsError.h"
+#include "nsISupportsImpl.h"
+#include "nsITransaction.h"
+#include "nsTransactionItem.h"
+#include "nsTransactionManager.h"
+#include "nsTransactionStack.h"
+
+nsTransactionItem::nsTransactionItem(nsITransaction *aTransaction)
+    : mTransaction(aTransaction), mUndoStack(0), mRedoStack(0)
+{
+}
+
+nsTransactionItem::~nsTransactionItem()
+{
+  delete mRedoStack;
+
+  delete mUndoStack;
+}
+
+void
+nsTransactionItem::CleanUp()
+{
+  mData.Clear();
+  mTransaction = nullptr;
+  if (mRedoStack) {
+    mRedoStack->DoUnlink();
+  }
+  if (mUndoStack) {
+    mUndoStack->DoUnlink();
+  }
+}
+
+NS_IMPL_CYCLE_COLLECTING_NATIVE_ADDREF(nsTransactionItem)
+NS_IMPL_CYCLE_COLLECTING_NATIVE_RELEASE_WITH_LAST_RELEASE(nsTransactionItem,
+                                                          CleanUp())
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(nsTransactionItem)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsTransactionItem)
+  tmp->CleanUp();
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsTransactionItem)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mData)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTransaction)
+  if (tmp->mRedoStack) {
+    tmp->mRedoStack->DoTraverse(cb);
+  }
+  if (tmp->mUndoStack) {
+    tmp->mUndoStack->DoTraverse(cb);
+  }
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(nsTransactionItem, AddRef)
+NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(nsTransactionItem, Release)
+
+nsresult
+nsTransactionItem::AddChild(nsTransactionItem *aTransactionItem)
+{
+  NS_ENSURE_TRUE(aTransactionItem, NS_ERROR_NULL_POINTER);
+
+  if (!mUndoStack) {
+    mUndoStack = new nsTransactionStack(nsTransactionStack::FOR_UNDO);
+  }
+
+  mUndoStack->Push(aTransactionItem);
+
+  return NS_OK;
+}
+
+already_AddRefed<nsITransaction>
+nsTransactionItem::GetTransaction()
+{
+  nsCOMPtr<nsITransaction> txn = mTransaction;
+  return txn.forget();
+}
+
+nsresult
+nsTransactionItem::GetIsBatch(bool *aIsBatch)
+{
+  NS_ENSURE_TRUE(aIsBatch, NS_ERROR_NULL_POINTER);
+
+  *aIsBatch = !mTransaction;
+
+  return NS_OK;
+}
+
+nsresult
+nsTransactionItem::GetNumberOfChildren(int32_t *aNumChildren)
+{
+  nsresult result;
+
+  NS_ENSURE_TRUE(aNumChildren, NS_ERROR_NULL_POINTER);
+
+  *aNumChildren = 0;
+
+  int32_t ui = 0;
+  int32_t ri = 0;
+
+  result = GetNumberOfUndoItems(&ui);
+
+  NS_ENSURE_SUCCESS(result, result);
+
+  result = GetNumberOfRedoItems(&ri);
+
+  NS_ENSURE_SUCCESS(result, result);
+
+  *aNumChildren = ui + ri;
+
+  return NS_OK;
+}
+
+nsresult
+nsTransactionItem::GetChild(int32_t aIndex, nsTransactionItem **aChild)
+{
+  NS_ENSURE_TRUE(aChild, NS_ERROR_NULL_POINTER);
+
+  *aChild = 0;
+
+  int32_t numItems = 0;
+  nsresult result = GetNumberOfChildren(&numItems);
+
+  NS_ENSURE_SUCCESS(result, result);
+
+  if (aIndex < 0 || aIndex >= numItems)
+    return NS_ERROR_FAILURE;
+
+  // Children are expected to be in the order they were added,
+  // so the child first added would be at the bottom of the undo
+  // stack, or if there are no items on the undo stack, it would
+  // be at the top of the redo stack.
+
+  result = GetNumberOfUndoItems(&numItems);
+
+  NS_ENSURE_SUCCESS(result, result);
+
+  if (numItems > 0 && aIndex < numItems) {
+    NS_ENSURE_TRUE(mUndoStack, NS_ERROR_FAILURE);
+
+    nsRefPtr<nsTransactionItem> child = mUndoStack->GetItem(aIndex);
+    child.forget(aChild);
+    return *aChild ? NS_OK : NS_ERROR_FAILURE;
+  }
+
+  // Adjust the index for the redo stack:
+
+  aIndex -=  numItems;
+
+  result = GetNumberOfRedoItems(&numItems);
+
+  NS_ENSURE_SUCCESS(result, result);
+
+  NS_ENSURE_TRUE(mRedoStack && numItems != 0 && aIndex < numItems, NS_ERROR_FAILURE);
+
+  nsRefPtr<nsTransactionItem> child = mRedoStack->GetItem(aIndex);
+  child.forget(aChild);
+  return *aChild ? NS_OK : NS_ERROR_FAILURE;
+}
+
+nsresult
+nsTransactionItem::DoTransaction()
+{
+  if (mTransaction)
+    return mTransaction->DoTransaction();
+  return NS_OK;
+}
+
+nsresult
+nsTransactionItem::UndoTransaction(nsTransactionManager *aTxMgr)
+{
+  nsresult result = UndoChildren(aTxMgr);
+
+  if (NS_FAILED(result)) {
+    RecoverFromUndoError(aTxMgr);
+    return result;
+  }
+
+  if (!mTransaction)
+    return NS_OK;
+
+  result = mTransaction->UndoTransaction();
+
+  if (NS_FAILED(result)) {
+    RecoverFromUndoError(aTxMgr);
+    return result;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+nsTransactionItem::UndoChildren(nsTransactionManager *aTxMgr)
+{
+  nsRefPtr<nsTransactionItem> item;
+  nsresult result = NS_OK;
+  int32_t sz = 0;
+
+  if (mUndoStack) {
+    if (!mRedoStack && mUndoStack) {
+      mRedoStack = new nsTransactionStack(nsTransactionStack::FOR_REDO);
+    }
+
+    /* Undo all of the transaction items children! */
+    sz = mUndoStack->GetSize();
+
+    while (sz-- > 0) {
+      item = mUndoStack->Peek();
+
+      if (!item) {
+        return NS_ERROR_FAILURE;
+      }
+
+      nsCOMPtr<nsITransaction> t = item->GetTransaction();
+
+      bool doInterrupt = false;
+
+      result = aTxMgr->WillUndoNotify(t, &doInterrupt);
+
+      if (NS_FAILED(result)) {
+        return result;
+      }
+
+      if (doInterrupt) {
+        return NS_OK;
+      }
+
+      result = item->UndoTransaction(aTxMgr);
+
+      if (NS_SUCCEEDED(result)) {
+        item = mUndoStack->Pop();
+        mRedoStack->Push(item);
+      }
+
+      nsresult result2 = aTxMgr->DidUndoNotify(t, result);
+
+      if (NS_SUCCEEDED(result)) {
+        result = result2;
+      }
+    }
+  }
+
+  return result;
+}
+
+nsresult
+nsTransactionItem::RedoTransaction(nsTransactionManager *aTxMgr)
+{
+  nsresult result;
+
+  nsCOMPtr<nsITransaction> kungfuDeathGrip(mTransaction);
+  if (mTransaction) {
+    result = mTransaction->RedoTransaction();
+
+    NS_ENSURE_SUCCESS(result, result);
+  }
+
+  result = RedoChildren(aTxMgr);
+
+  if (NS_FAILED(result)) {
+    RecoverFromRedoError(aTxMgr);
+    return result;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+nsTransactionItem::RedoChildren(nsTransactionManager *aTxMgr)
+{
+  nsRefPtr<nsTransactionItem> item;
+  nsresult result = NS_OK;
+
+  if (!mRedoStack)
+    return NS_OK;
+
+  /* Redo all of the transaction items children! */
+  int32_t sz = mRedoStack->GetSize();
+
+  while (sz-- > 0) {
+    item = mRedoStack->Peek();
+
+    if (!item) {
+      return NS_ERROR_FAILURE;
+    }
+
+    nsCOMPtr<nsITransaction> t = item->GetTransaction();
+
+    bool doInterrupt = false;
+
+    result = aTxMgr->WillRedoNotify(t, &doInterrupt);
+
+    if (NS_FAILED(result)) {
+      return result;
+    }
+
+    if (doInterrupt) {
+      return NS_OK;
+    }
+
+    result = item->RedoTransaction(aTxMgr);
+
+    if (NS_SUCCEEDED(result)) {
+      item = mRedoStack->Pop();
+      mUndoStack->Push(item);
+    }
+
+    nsresult result2 = aTxMgr->DidUndoNotify(t, result);
+
+    if (NS_SUCCEEDED(result)) {
+      result = result2;
+    }
+  }
+
+  return result;
+}
+
+nsresult
+nsTransactionItem::GetNumberOfUndoItems(int32_t *aNumItems)
+{
+  NS_ENSURE_TRUE(aNumItems, NS_ERROR_NULL_POINTER);
+
+  if (!mUndoStack) {
+    *aNumItems = 0;
+    return NS_OK;
+  }
+
+  *aNumItems = mUndoStack->GetSize();
+  return *aNumItems ? NS_OK : NS_ERROR_FAILURE;
+}
+
+nsresult
+nsTransactionItem::GetNumberOfRedoItems(int32_t *aNumItems)
+{
+  NS_ENSURE_TRUE(aNumItems, NS_ERROR_NULL_POINTER);
+
+  if (!mRedoStack) {
+    *aNumItems = 0;
+    return NS_OK;
+  }
+
+  *aNumItems = mRedoStack->GetSize();
+  return *aNumItems ? NS_OK : NS_ERROR_FAILURE;
+}
+
+nsresult
+nsTransactionItem::RecoverFromUndoError(nsTransactionManager *aTxMgr)
+{
+  //
+  // If this method gets called, we never got to the point where we
+  // successfully called UndoTransaction() for the transaction item itself.
+  // Just redo any children that successfully called undo!
+  //
+  return RedoChildren(aTxMgr);
+}
+
+nsresult
+nsTransactionItem::RecoverFromRedoError(nsTransactionManager *aTxMgr)
+{
+  //
+  // If this method gets called, we already successfully called
+  // RedoTransaction() for the transaction item itself. Undo all
+  // the children that successfully called RedoTransaction(),
+  // then undo the transaction item itself.
+  //
+
+  nsresult result;
+
+  result = UndoChildren(aTxMgr);
+
+  if (NS_FAILED(result)) {
+    return result;
+  }
+
+  if (!mTransaction)
+    return NS_OK;
+
+  return mTransaction->UndoTransaction();
+}
+