Add m-esr52 at 52.6.0

20 files changed, 6711 insertions, 0 deletions

diff --git a/editor/txmgr/moz.build b/editor/txmgr/moz.build
new file mode 100644
index 000000000..3c7f3b55a
--- /dev/null
+++ b/editor/txmgr/moz.build
@@ -0,0 +1,30 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+TEST_DIRS += ['tests']
+
+XPIDL_SOURCES += [
+    'nsITransaction.idl',
+    'nsITransactionList.idl',
+    'nsITransactionListener.idl',
+    'nsITransactionManager.idl',
+]
+
+XPIDL_MODULE = 'txmgr'
+
+EXPORTS += [
+    'nsTransactionManagerCID.h',
+]
+
+UNIFIED_SOURCES += [
+    'nsTransactionItem.cpp',
+    'nsTransactionList.cpp',
+    'nsTransactionManager.cpp',
+    'nsTransactionManagerFactory.cpp',
+    'nsTransactionStack.cpp',
+]
+
+FINAL_LIBRARY = 'xul'
diff --git a/editor/txmgr/nsITransaction.idl b/editor/txmgr/nsITransaction.idl
new file mode 100644
index 000000000..7e2e2aee4
--- /dev/null
+++ b/editor/txmgr/nsITransaction.idl
@@ -0,0 +1,63 @@
+/* -*- 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 "nsISupports.idl"
+
+/*
+ * The nsITransaction interface.
+ * <P>
+ * This interface is implemented by an object that needs to
+ * execute some behavior that must be tracked by the transaction manager.
+ */
+[scriptable, uuid(58e330c1-7b48-11d2-98b9-00805f297d89)]
+interface nsITransaction : nsISupports
+{
+  /**
+   * Executes the transaction.
+   */
+  void doTransaction();
+
+  /**
+   * Restores the state to what it was before the transaction was executed.
+   */
+  void undoTransaction();
+
+  /**
+   * Executes the transaction again. Can only be called on a transaction that
+   * was previously undone.
+   * <P>
+   * In most cases, the redoTransaction() method will actually call the
+   * doTransaction() method to execute the transaction again.
+   */
+  void redoTransaction();
+
+  /**
+   * The transaction's transient state. This attribute is checked by
+   * the transaction manager after the transaction's Execute() method is called.
+   * If the transient state is false, a reference to the transaction is
+   * held by the transaction manager so that the transactions' undoTransaction()
+   * and redoTransaction() methods can be called. If the transient state is
+   * true, the transaction manager returns immediately after the transaction's
+   * doTransaction() method is called, no references to the transaction are
+   * maintained. Transient transactions cannot be undone or redone by the
+   * transaction manager.
+   */
+  readonly attribute boolean isTransient;
+
+  /**
+   * Attempts to merge a transaction into "this" transaction. Both transactions
+   * must be in their undo state, doTransaction() methods already called. The
+   * transaction manager calls this method to coalesce a new transaction with
+   * the transaction on the top of the undo stack.
+   * This method returns a boolean value that indicates the merge result.
+   * A true value indicates that the transactions were merged successfully,
+   * a false value if the merge was not possible or failed. If true,
+   * the transaction manager will Release() the new transacton instead of
+   * pushing it on the undo stack.
+   * @param aTransaction the previously executed transaction to merge.
+   */
+  boolean merge(in nsITransaction aTransaction);
+};
+
diff --git a/editor/txmgr/nsITransactionList.idl b/editor/txmgr/nsITransactionList.idl
new file mode 100644
index 000000000..de6d191de
--- /dev/null
+++ b/editor/txmgr/nsITransactionList.idl
@@ -0,0 +1,70 @@
+/* -*- 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 "nsISupports.idl"
+
+interface nsITransaction;
+
+/*
+ * The nsITransactionList interface.
+ * <P>
+ * The implementation for this interface is provided by the Transaction Manager.
+ * This interface provides a mechanism for accessing the transactions on the
+ * Undo or Redo stacks as well as any auto-aggregated children that a
+ * transaction may have.
+ */
+[scriptable, uuid(d007ceff-c978-486a-b697-384ca01997be)]
+
+interface nsITransactionList : nsISupports
+{
+  /**
+   * The number of transactions contained in this list.
+   */
+  readonly attribute long numItems;
+
+  /**
+   * itemIsBatch() returns true if the item at aIndex is a batch. Note that
+   * currently there is no requirement for a TransactionManager implementation
+   * to associate a toplevel nsITransaction with a batch so it is possible for
+   * itemIsBatch() to return true and getItem() to return null. However, you
+   * can still access the transactions contained in the batch with a call to
+   * getChildListForItem().
+   * @param aIndex The index of the item in the list.
+   */
+  boolean itemIsBatch(in long aIndex);
+
+  /**
+   * getItem() returns the transaction at the given index in the list. Note that
+   * a null can be returned here if the item is a batch. The transaction
+   * returned is AddRef'd so it is up to the caller to Release the transaction
+   * when it is done.
+   * @param aIndex The index of the item in the list.
+   */
+  nsITransaction getItem(in long aIndex);
+
+  /**
+   * getData() returns the data (of type nsISupports array) associated with
+   * the transaction list.
+   */
+  void getData(in long aIndex, [optional] out unsigned long aLength,
+               [array, size_is(aLength), retval] out nsISupports aData);
+
+  /**
+   * getNumChildrenForItem() returns the number of child (auto-aggreated)
+   * transactions the item at aIndex has.
+   * @param aIndex The index of the item in the list.
+   */
+  long getNumChildrenForItem(in long aIndex);
+
+  /**
+   * getChildListForItem() returns the list of children associated with the
+   * item at aIndex. Implementations may return null if there are no children,
+   * or an empty list. The list returned is AddRef'd so it is up to the caller
+   * to Release the transaction when it is done.
+   * @param aIndex The index of the item in the list.
+   */
+  nsITransactionList getChildListForItem(in long aIndex);
+};
+
diff --git a/editor/txmgr/nsITransactionListener.idl b/editor/txmgr/nsITransactionListener.idl
new file mode 100644
index 000000000..c63f9e3b8
--- /dev/null
+++ b/editor/txmgr/nsITransactionListener.idl
@@ -0,0 +1,170 @@
+/* -*- 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 "nsISupports.idl"
+
+interface nsITransaction;
+interface nsITransactionManager;
+
+/**
+ * The nsITransactionListener interface.
+ * <P>
+ * This interface is implemented by an object that tracks transactions.
+ */
+[scriptable, uuid(58e330c4-7b48-11d2-98b9-00805f297d89)]
+interface nsITransactionListener : nsISupports
+{
+  /**
+   * Called before a transaction manager calls a transaction's
+   * doTransaction() method.
+   * @param aManager the transaction manager doing the transaction.
+   * @param aTransaction the transaction being executed.
+   * @result boolean value returned by listener which indicates
+   * its desire to interrupt normal control flow. Listeners should
+   * return true if they want to interrupt normal control flow, without
+   * throwing an error.
+   */
+  boolean willDo(in nsITransactionManager aManager,
+                      in nsITransaction aTransaction);
+
+  /**
+   * Called after a transaction manager calls the doTransaction() method of
+   * a transaction.
+   * @param aManager the transaction manager that did the transaction.
+   * @param aTransaction the transaction that was executed.
+   * @param aDoResult the nsresult returned after executing
+   * the transaction.
+   */
+  void didDo(in nsITransactionManager aManager,
+             in nsITransaction aTransaction,
+             in nsresult aDoResult);
+
+  /**
+   * Called before a transaction manager calls the Undo() method of
+   * a transaction.
+   * @param aManager the transaction manager undoing the transaction.
+   * @param aTransaction the transaction being undone.
+   * @result boolean value returned by listener which indicates
+   * its desire to interrupt normal control flow. Listeners should
+   * return true if they want to interrupt normal control flow, without
+   * throwing an error. Note that listeners can also interrupt normal
+   * control flow by throwing an nsresult that indicates an error.
+   */
+  boolean willUndo(in nsITransactionManager aManager,
+                   in nsITransaction aTransaction);
+
+  /**
+   * Called after a transaction manager calls the Undo() method of
+   * a transaction.
+   * @param aManager the transaction manager undoing the transaction.
+   * @param aTransaction the transaction being undone.
+   * @param aUndoResult the nsresult returned after undoing the transaction.
+   */
+  void didUndo(in nsITransactionManager aManager,
+               in nsITransaction aTransaction,
+               in nsresult aUndoResult);
+
+  /**
+   * Called before a transaction manager calls the Redo() method of
+   * a transaction.
+   * @param aManager the transaction manager redoing the transaction.
+   * @param aTransaction the transaction being redone.
+   * @result boolean value returned by listener which indicates
+   * its desire to interrupt normal control flow. Listeners should
+   * return true if they want to interrupt normal control flow, without
+   * throwing an error. Note that listeners can also interrupt normal
+   * control flow by throwing an nsresult that indicates an error.
+   */
+  boolean willRedo(in nsITransactionManager aManager,
+                   in nsITransaction aTransaction);
+
+  /**
+   * Called after a transaction manager calls the Redo() method of
+   * a transaction.
+   * @param aManager the transaction manager redoing the transaction.
+   * @param aTransaction the transaction being redone.
+   * @param aRedoResult the nsresult returned after redoing the transaction.
+   */
+  void didRedo(in nsITransactionManager aManager,
+               in nsITransaction aTransaction,
+               in nsresult aRedoResult);
+
+  /**
+   * Called before a transaction manager begins a batch.
+   * @param aManager the transaction manager beginning a batch.
+   * @result boolean value returned by listener which indicates
+   * its desire to interrupt normal control flow. Listeners should
+   * return true if they want to interrupt normal control flow, without
+   * throwing an error. Note that listeners can also interrupt normal
+   * control flow by throwing an nsresult that indicates an error.
+   */
+  boolean willBeginBatch(in nsITransactionManager aManager);
+
+  /**
+   * Called after a transaction manager begins a batch.
+   * @param aManager the transaction manager that began a batch.
+   * @param aResult the nsresult returned after beginning a batch.
+   */
+  void didBeginBatch(in nsITransactionManager aManager,
+                     in nsresult aResult);
+
+  /**
+   * Called before a transaction manager ends a batch.
+   * @param aManager the transaction manager ending a batch.
+   * @result boolean value returned by listener which indicates
+   * its desire to interrupt normal control flow. Listeners should
+   * return true if they want to interrupt normal control flow, without
+   * throwing an error. Note that listeners can also interrupt normal
+   * control flow by throwing an nsresult that indicates an error.
+   */
+  boolean willEndBatch(in nsITransactionManager aManager);
+
+  /**
+   * Called after a transaction manager ends a batch.
+   * @param aManager the transaction manager ending a batch.
+   * @param aResult the nsresult returned after ending a batch.
+   */
+  void didEndBatch(in nsITransactionManager aManager,
+                   in nsresult aResult);
+
+  /**
+   * Called before a transaction manager tries to merge
+   * a transaction, that was just executed, with the
+   * transaction at the top of the undo stack.
+   * @param aManager the transaction manager ending a batch.
+   * @param aTopTransaction the transaction at the top of the undo stack.
+   * @param aTransactionToMerge the transaction to merge.
+   * @result boolean value returned by listener which indicates
+   * its desire to interrupt normal control flow. Listeners should
+   * return true if they want to interrupt normal control flow, without
+   * throwing an error. Note that listeners can also interrupt normal
+   * control flow by throwing an nsresult that indicates an error.
+   */
+  boolean willMerge(in nsITransactionManager aManager,
+                    in nsITransaction aTopTransaction,
+                    in nsITransaction aTransactionToMerge);
+
+  /**
+   * Called after a transaction manager tries to merge
+   * a transaction, that was just executed, with the
+   * transaction at the top of the undo stack.
+   * @param aManager the transaction manager ending a batch.
+   * @param aTopTransaction the transaction at the top of the undo stack.
+   * @param aTransactionToMerge the transaction to merge.
+   * @param aDidMerge true if transaction was merged, else false.
+   * @param aMergeResult the nsresult returned after the merge attempt.
+   * @param aInterrupt listeners should set this to PR_TRUE if they
+   * want to interrupt normal control flow, without throwing an error.
+   */
+  void didMerge(in nsITransactionManager aManager,
+                in nsITransaction aTopTransaction,
+                in nsITransaction aTransactionToMerge,
+                in boolean aDidMerge,
+                in nsresult aMergeResult);
+
+
+  /* XXX: We should probably add pruning notification methods. */
+};
+
diff --git a/editor/txmgr/nsITransactionManager.idl b/editor/txmgr/nsITransactionManager.idl
new file mode 100644
index 000000000..0587d5ca1
--- /dev/null
+++ b/editor/txmgr/nsITransactionManager.idl
@@ -0,0 +1,168 @@
+/* -*- 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 "nsISupports.idl"
+#include "nsITransaction.idl"
+#include "nsITransactionList.idl"
+#include "nsITransactionListener.idl"
+
+%{ C++
+
+#define NS_TRANSACTIONMANAGER_CONTRACTID "@mozilla.org/transactionmanager;1"
+
+%} C++
+
+/**
+ * The nsITransactionManager interface.
+ * <P>
+ * This interface is implemented by an object that wants to
+ * manage/track transactions.
+ */
+[scriptable, builtinclass, uuid(c77763df-0fb9-41a8-8074-8e882f605755)]
+interface nsITransactionManager : nsISupports
+{
+  /**
+   * Calls a transaction's doTransaction() method, then pushes it on the
+   * undo stack.
+   * <P>
+   * This method calls the transaction's AddRef() method.
+   * The transaction's Release() method will be called when the undo or redo
+   * stack is pruned or when the transaction manager is destroyed.
+   * @param aTransaction the transaction to do.
+   */
+  void doTransaction(in nsITransaction aTransaction);
+
+  /**
+   * Pops the topmost transaction on the undo stack, calls its
+   * undoTransaction() method, then pushes it on the redo stack.
+   */
+  void undoTransaction();
+
+  /**
+   * Pops the topmost transaction on the redo stack, calls its
+   * redoTransaction() method, then pushes it on the undo stack.
+   */
+  void redoTransaction();
+
+  /**
+   * Clears the undo and redo stacks.
+   */
+  void clear();
+
+  /**
+   * Clears the undo stack only.
+   */
+  void clearUndoStack();
+
+  /**
+   * Clears the redo stack only.
+   */
+  void clearRedoStack();
+
+  /**
+   * Turns on the transaction manager's batch mode, forcing all transactions
+   * executed by the transaction manager's doTransaction() method to be
+   * aggregated together until EndBatch() is called.  This mode allows an
+   * application to execute and group together several independent transactions
+   * so they can be undone with a single call to undoTransaction().
+   * @param aData An arbitrary nsISupports object that is associated with the
+   * batch. Can be retrieved from nsITransactionList.
+   */
+  void beginBatch(in nsISupports aData);
+
+  /**
+   * Turns off the transaction manager's batch mode.
+   * @param aAllowEmpty If true, a batch containing no children will be
+   * pushed onto the undo stack. Otherwise, ending a batch with no
+   * children will result in no transactions being pushed on the undo stack.
+   */
+  void endBatch(in boolean aAllowEmpty);
+
+  /**
+   * The number of items on the undo stack.
+   */
+  readonly attribute long numberOfUndoItems;
+
+  /**
+   * The number of items on the redo stack.
+   */
+  readonly attribute long numberOfRedoItems;
+
+  /**
+   * Sets the maximum number of transaction items the transaction manager will
+   * maintain at any time. This is commonly referred to as the number of levels
+   * of undo.
+   * @param aMaxCount A value of -1 means no limit. A value of zero means the
+   * transaction manager will execute each transaction, then immediately release
+   * all references it has to the transaction without pushing it on the undo
+   * stack. A value greater than zero indicates the max number of transactions
+   * that can exist at any time on both the undo and redo stacks. This method
+   * will prune the necessary number of transactions on the undo and redo
+   * stacks if the value specified is less than the number of items that exist
+   * on both the undo and redo stacks.
+   */
+  attribute long maxTransactionCount;
+
+  /**
+   * Combines the transaction at the top of the undo stack (if any) with the
+   * preceding undo transaction (if any) into a batch transaction. Thus,
+   * a call to undoTransaction() will undo both transactions.
+   */
+  void batchTopUndo();
+
+  /**
+   * Removes the transaction at the top of the undo stack (if any) without
+   * transacting.
+   */
+  void removeTopUndo();
+
+  /**
+   * Returns an AddRef'd pointer to the transaction at the top of the
+   * undo stack. Callers should be aware that this method could return
+   * return a null in some implementations if there is a batch at the top
+   * of the undo stack.
+   */
+  nsITransaction peekUndoStack();
+
+  /**
+   * Returns an AddRef'd pointer to the transaction at the top of the
+   * redo stack. Callers should be aware that this method could return
+   * return a null in some implementations if there is a batch at the top
+   * of the redo stack.
+   */
+  nsITransaction peekRedoStack();
+
+  /**
+   * Returns the list of transactions on the undo stack. Note that the
+   * transaction at the top of the undo stack will actually be at the
+   * index 'n-1' in the list, where 'n' is the number of items in the list.
+   */
+  nsITransactionList getUndoList();
+
+  /**
+   * Returns the list of transactions on the redo stack. Note that the
+   * transaction at the top of the redo stack will actually be at the
+   * index 'n-1' in the list, where 'n' is the number of items in the list.
+   */
+  nsITransactionList getRedoList();
+
+  /**
+   * Adds a listener to the transaction manager's notification list. Listeners
+   * are notified whenever a transaction is done, undone, or redone.
+   * <P>
+   * The listener's AddRef() method is called.
+   * @param aListener the lister to add.
+   */
+  void AddListener(in nsITransactionListener aListener);
+
+  /**
+   * Removes a listener from the transaction manager's notification list.
+   * <P>
+   * The listener's Release() method is called.
+   * @param aListener the lister to remove.
+   */
+  void RemoveListener(in nsITransactionListener aListener);
+};
+
diff --git a/editor/txmgr/nsTransactionItem.cpp b/editor/txmgr/nsTransactionItem.cpp
new file mode 100644
index 000000000..afea20a0b
--- /dev/null
+++ b/editor/txmgr/nsTransactionItem.cpp
@@ -0,0 +1,349 @@
+/* -*- 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 "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)
+{
+  NS_ENSURE_TRUE(aNumChildren, NS_ERROR_NULL_POINTER);
+
+  *aNumChildren = 0;
+
+  int32_t ui = 0;
+  nsresult rv = GetNumberOfUndoItems(&ui);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  int32_t ri = 0;
+  rv = GetNumberOfRedoItems(&ri);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *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 rv = GetNumberOfChildren(&numItems);
+  NS_ENSURE_SUCCESS(rv, rv);
+  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.
+  rv = GetNumberOfUndoItems(&numItems);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (numItems > 0 && aIndex < numItems) {
+    NS_ENSURE_TRUE(mUndoStack, NS_ERROR_FAILURE);
+
+    RefPtr<nsTransactionItem> child = mUndoStack->GetItem(aIndex);
+    child.forget(aChild);
+    return *aChild ? NS_OK : NS_ERROR_FAILURE;
+  }
+
+  // Adjust the index for the redo stack:
+  aIndex -=  numItems;
+
+  rv = GetNumberOfRedoItems(&numItems);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_TRUE(mRedoStack && numItems != 0 && aIndex < numItems, NS_ERROR_FAILURE);
+
+  RefPtr<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 rv = UndoChildren(aTxMgr);
+  if (NS_FAILED(rv)) {
+    RecoverFromUndoError(aTxMgr);
+    return rv;
+  }
+
+  if (!mTransaction) {
+    return NS_OK;
+  }
+
+  rv = mTransaction->UndoTransaction();
+  if (NS_FAILED(rv)) {
+    RecoverFromUndoError(aTxMgr);
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+nsTransactionItem::UndoChildren(nsTransactionManager *aTxMgr)
+{
+  if (mUndoStack) {
+    if (!mRedoStack && mUndoStack) {
+      mRedoStack = new nsTransactionStack(nsTransactionStack::FOR_REDO);
+    }
+
+    /* Undo all of the transaction items children! */
+    int32_t sz = mUndoStack->GetSize();
+
+    nsresult rv = NS_OK;
+    while (sz-- > 0) {
+      RefPtr<nsTransactionItem> item = mUndoStack->Peek();
+      if (!item) {
+        return NS_ERROR_FAILURE;
+      }
+
+      nsCOMPtr<nsITransaction> t = item->GetTransaction();
+      bool doInterrupt = false;
+      rv = aTxMgr->WillUndoNotify(t, &doInterrupt);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      if (doInterrupt) {
+        return NS_OK;
+      }
+
+      rv = item->UndoTransaction(aTxMgr);
+      if (NS_SUCCEEDED(rv)) {
+        item = mUndoStack->Pop();
+        mRedoStack->Push(item.forget());
+      }
+
+      nsresult rv2 = aTxMgr->DidUndoNotify(t, rv);
+      if (NS_SUCCEEDED(rv)) {
+        rv = rv2;
+      }
+    }
+    // XXX NS_OK if there is no Undo items or all methods work fine, otherwise,
+    //     the result of the last item's UndoTransaction() or
+    //     DidUndoNotify() if UndoTransaction() succeeded.
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+nsTransactionItem::RedoTransaction(nsTransactionManager *aTxMgr)
+{
+  nsCOMPtr<nsITransaction> transaction(mTransaction);
+  if (transaction) {
+    nsresult rv = transaction->RedoTransaction();
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  nsresult rv = RedoChildren(aTxMgr);
+  if (NS_FAILED(rv)) {
+    RecoverFromRedoError(aTxMgr);
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+nsTransactionItem::RedoChildren(nsTransactionManager *aTxMgr)
+{
+  if (!mRedoStack) {
+    return NS_OK;
+  }
+
+  /* Redo all of the transaction items children! */
+  int32_t sz = mRedoStack->GetSize();
+
+  nsresult rv = NS_OK;
+  while (sz-- > 0) {
+    RefPtr<nsTransactionItem> item = mRedoStack->Peek();
+    if (!item) {
+      return NS_ERROR_FAILURE;
+    }
+
+    nsCOMPtr<nsITransaction> t = item->GetTransaction();
+    bool doInterrupt = false;
+    rv = aTxMgr->WillRedoNotify(t, &doInterrupt);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    if (doInterrupt) {
+      return NS_OK;
+    }
+
+    rv = item->RedoTransaction(aTxMgr);
+    if (NS_SUCCEEDED(rv)) {
+      item = mRedoStack->Pop();
+      mUndoStack->Push(item.forget());
+    }
+
+    // XXX Shouldn't this DidRedoNotify()? (bug 1311626)
+    nsresult rv2 = aTxMgr->DidUndoNotify(t, rv);
+    if (NS_SUCCEEDED(rv)) {
+      rv = rv2;
+    }
+  }
+  // XXX NS_OK if there is no Redo items or all methods work fine, otherwise,
+  //     the result of the last item's RedoTransaction() or
+  //     DidUndoNotify() if UndoTransaction() succeeded.
+  return rv;
+}
+
+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 rv = UndoChildren(aTxMgr);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (!mTransaction) {
+    return NS_OK;
+  }
+
+  return mTransaction->UndoTransaction();
+}
+
diff --git a/editor/txmgr/nsTransactionItem.h b/editor/txmgr/nsTransactionItem.h
new file mode 100644
index 000000000..dc868203b
--- /dev/null
+++ b/editor/txmgr/nsTransactionItem.h
@@ -0,0 +1,68 @@
+/* -*- 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/. */
+
+#ifndef nsTransactionItem_h__
+#define nsTransactionItem_h__
+
+#include "nsCOMPtr.h"
+#include "nsCOMArray.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsISupportsImpl.h"
+#include "nscore.h"
+
+class nsITransaction;
+class nsTransactionManager;
+class nsTransactionStack;
+
+class nsTransactionItem final
+{
+  nsCOMArray<nsISupports>  mData;
+  nsCOMPtr<nsITransaction> mTransaction;
+  nsTransactionStack      *mUndoStack;
+  nsTransactionStack      *mRedoStack;
+
+public:
+
+  explicit nsTransactionItem(nsITransaction *aTransaction);
+  NS_METHOD_(MozExternalRefCountType) AddRef();
+  NS_METHOD_(MozExternalRefCountType) Release();
+
+  NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(nsTransactionItem)
+
+  virtual nsresult AddChild(nsTransactionItem *aTransactionItem);
+  already_AddRefed<nsITransaction> GetTransaction();
+  virtual nsresult GetIsBatch(bool *aIsBatch);
+  virtual nsresult GetNumberOfChildren(int32_t *aNumChildren);
+  virtual nsresult GetChild(int32_t aIndex, nsTransactionItem **aChild);
+
+  virtual nsresult DoTransaction(void);
+  virtual nsresult UndoTransaction(nsTransactionManager *aTxMgr);
+  virtual nsresult RedoTransaction(nsTransactionManager *aTxMgr);
+
+  nsCOMArray<nsISupports>& GetData()
+  {
+    return mData;
+  }
+
+private:
+
+  virtual nsresult UndoChildren(nsTransactionManager *aTxMgr);
+  virtual nsresult RedoChildren(nsTransactionManager *aTxMgr);
+
+  virtual nsresult RecoverFromUndoError(nsTransactionManager *aTxMgr);
+  virtual nsresult RecoverFromRedoError(nsTransactionManager *aTxMgr);
+
+  virtual nsresult GetNumberOfUndoItems(int32_t *aNumItems);
+  virtual nsresult GetNumberOfRedoItems(int32_t *aNumItems);
+
+  void CleanUp();
+protected:
+  virtual ~nsTransactionItem();
+
+  nsCycleCollectingAutoRefCnt mRefCnt;
+  NS_DECL_OWNINGTHREAD
+};
+
+#endif // nsTransactionItem_h__
diff --git a/editor/txmgr/nsTransactionList.cpp b/editor/txmgr/nsTransactionList.cpp
new file mode 100644
index 000000000..756edfd49
--- /dev/null
+++ b/editor/txmgr/nsTransactionList.cpp
@@ -0,0 +1,174 @@
+/* -*- 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 "nsCOMPtr.h"
+#include "nsDebug.h"
+#include "nsError.h"
+#include "nsID.h"
+#include "nsISupportsUtils.h"
+#include "nsITransactionManager.h"
+#include "nsTransactionItem.h"
+#include "nsTransactionList.h"
+#include "nsTransactionStack.h"
+#include "nscore.h"
+
+NS_IMPL_ISUPPORTS(nsTransactionList, nsITransactionList)
+
+nsTransactionList::nsTransactionList(nsITransactionManager *aTxnMgr, nsTransactionStack *aTxnStack)
+  : mTxnStack(aTxnStack)
+  , mTxnItem(nullptr)
+{
+  if (aTxnMgr)
+    mTxnMgr = do_GetWeakReference(aTxnMgr);
+}
+
+nsTransactionList::nsTransactionList(nsITransactionManager *aTxnMgr, nsTransactionItem *aTxnItem)
+  : mTxnStack(0)
+  , mTxnItem(aTxnItem)
+{
+  if (aTxnMgr)
+    mTxnMgr = do_GetWeakReference(aTxnMgr);
+}
+
+nsTransactionList::~nsTransactionList()
+{
+  mTxnStack = 0;
+  mTxnItem  = nullptr;
+}
+
+NS_IMETHODIMP nsTransactionList::GetNumItems(int32_t *aNumItems)
+{
+  NS_ENSURE_TRUE(aNumItems, NS_ERROR_NULL_POINTER);
+
+  *aNumItems = 0;
+
+  nsCOMPtr<nsITransactionManager> txMgr = do_QueryReferent(mTxnMgr);
+  NS_ENSURE_TRUE(txMgr, NS_ERROR_FAILURE);
+
+  if (mTxnStack) {
+    *aNumItems = mTxnStack->GetSize();
+  } else if (mTxnItem) {
+    return mTxnItem->GetNumberOfChildren(aNumItems);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsTransactionList::ItemIsBatch(int32_t aIndex, bool *aIsBatch)
+{
+  NS_ENSURE_TRUE(aIsBatch, NS_ERROR_NULL_POINTER);
+
+  *aIsBatch = false;
+
+  nsCOMPtr<nsITransactionManager> txMgr = do_QueryReferent(mTxnMgr);
+  NS_ENSURE_TRUE(txMgr, NS_ERROR_FAILURE);
+
+  RefPtr<nsTransactionItem> item;
+  if (mTxnStack) {
+    item = mTxnStack->GetItem(aIndex);
+  } else if (mTxnItem) {
+    nsresult rv = mTxnItem->GetChild(aIndex, getter_AddRefs(item));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  NS_ENSURE_TRUE(item, NS_ERROR_FAILURE);
+
+  return item->GetIsBatch(aIsBatch);
+}
+
+NS_IMETHODIMP nsTransactionList::GetData(int32_t aIndex,
+                                         uint32_t *aLength,
+                                         nsISupports ***aData)
+{
+  nsCOMPtr<nsITransactionManager> txMgr = do_QueryReferent(mTxnMgr);
+  NS_ENSURE_TRUE(txMgr, NS_ERROR_FAILURE);
+
+  RefPtr<nsTransactionItem> item;
+  if (mTxnStack) {
+    item = mTxnStack->GetItem(aIndex);
+  } else if (mTxnItem) {
+    nsresult rv = mTxnItem->GetChild(aIndex, getter_AddRefs(item));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  nsCOMArray<nsISupports>& data = item->GetData();
+  nsISupports** ret = static_cast<nsISupports**>(moz_xmalloc(data.Count() *
+    sizeof(nsISupports*)));
+
+  for (int32_t i = 0; i < data.Count(); i++) {
+    NS_ADDREF(ret[i] = data[i]);
+  }
+  *aLength = data.Count();
+  *aData = ret;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsTransactionList::GetItem(int32_t aIndex, nsITransaction **aItem)
+{
+  NS_ENSURE_TRUE(aItem, NS_ERROR_NULL_POINTER);
+
+  *aItem = 0;
+
+  nsCOMPtr<nsITransactionManager> txMgr = do_QueryReferent(mTxnMgr);
+  NS_ENSURE_TRUE(txMgr, NS_ERROR_FAILURE);
+
+  RefPtr<nsTransactionItem> item;
+  if (mTxnStack) {
+    item = mTxnStack->GetItem(aIndex);
+  } else if (mTxnItem) {
+    nsresult rv = mTxnItem->GetChild(aIndex, getter_AddRefs(item));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  NS_ENSURE_TRUE(item, NS_ERROR_FAILURE);
+
+  *aItem = item->GetTransaction().take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsTransactionList::GetNumChildrenForItem(int32_t aIndex, int32_t *aNumChildren)
+{
+  NS_ENSURE_TRUE(aNumChildren, NS_ERROR_NULL_POINTER);
+
+  *aNumChildren = 0;
+
+  nsCOMPtr<nsITransactionManager> txMgr = do_QueryReferent(mTxnMgr);
+  NS_ENSURE_TRUE(txMgr, NS_ERROR_FAILURE);
+
+  RefPtr<nsTransactionItem> item;
+  if (mTxnStack) {
+    item = mTxnStack->GetItem(aIndex);
+  } else if (mTxnItem) {
+    nsresult rv = mTxnItem->GetChild(aIndex, getter_AddRefs(item));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  NS_ENSURE_TRUE(item, NS_ERROR_FAILURE);
+
+  return item->GetNumberOfChildren(aNumChildren);
+}
+
+NS_IMETHODIMP nsTransactionList::GetChildListForItem(int32_t aIndex, nsITransactionList **aTxnList)
+{
+  NS_ENSURE_TRUE(aTxnList, NS_ERROR_NULL_POINTER);
+
+  *aTxnList = 0;
+
+  nsCOMPtr<nsITransactionManager> txMgr = do_QueryReferent(mTxnMgr);
+  NS_ENSURE_TRUE(txMgr, NS_ERROR_FAILURE);
+
+  RefPtr<nsTransactionItem> item;
+  if (mTxnStack) {
+    item = mTxnStack->GetItem(aIndex);
+  } else if (mTxnItem) {
+    nsresult rv = mTxnItem->GetChild(aIndex, getter_AddRefs(item));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  NS_ENSURE_TRUE(item, NS_ERROR_FAILURE);
+
+  *aTxnList = (nsITransactionList *)new nsTransactionList(txMgr, item);
+  NS_ENSURE_TRUE(*aTxnList, NS_ERROR_OUT_OF_MEMORY);
+
+  NS_ADDREF(*aTxnList);
+  return NS_OK;
+}
diff --git a/editor/txmgr/nsTransactionList.h b/editor/txmgr/nsTransactionList.h
new file mode 100644
index 000000000..e3dde1255
--- /dev/null
+++ b/editor/txmgr/nsTransactionList.h
@@ -0,0 +1,46 @@
+/* -*- 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/. */
+
+#ifndef nsTransactionList_h__
+#define nsTransactionList_h__
+
+#include "nsISupportsImpl.h"
+#include "nsITransactionList.h"
+#include "nsIWeakReferenceUtils.h"
+
+class nsITransaction;
+class nsITransactionManager;
+class nsTransactionItem;
+class nsTransactionStack;
+
+/** implementation of a transaction list object.
+ *
+ */
+class nsTransactionList : public nsITransactionList
+{
+private:
+
+  nsWeakPtr                   mTxnMgr;
+  nsTransactionStack         *mTxnStack;
+  RefPtr<nsTransactionItem> mTxnItem;
+
+protected:
+  virtual ~nsTransactionList();
+
+public:
+
+  nsTransactionList(nsITransactionManager *aTxnMgr, nsTransactionStack *aTxnStack);
+  nsTransactionList(nsITransactionManager *aTxnMgr, nsTransactionItem *aTxnItem);
+
+  /* Macro for AddRef(), Release(), and QueryInterface() */
+  NS_DECL_ISUPPORTS
+
+  /* nsITransactionManager method implementations. */
+  NS_DECL_NSITRANSACTIONLIST
+
+  /* nsTransactionList specific methods. */
+};
+
+#endif // nsTransactionList_h__
diff --git a/editor/txmgr/nsTransactionManager.cpp b/editor/txmgr/nsTransactionManager.cpp
new file mode 100644
index 000000000..10f9c3d06
--- /dev/null
+++ b/editor/txmgr/nsTransactionManager.cpp
@@ -0,0 +1,752 @@
+/* -*- 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/Assertions.h"
+#include "mozilla/mozalloc.h"
+#include "nsCOMPtr.h"
+#include "nsDebug.h"
+#include "nsError.h"
+#include "nsISupportsBase.h"
+#include "nsISupportsUtils.h"
+#include "nsITransaction.h"
+#include "nsITransactionList.h"
+#include "nsITransactionListener.h"
+#include "nsIWeakReference.h"
+#include "nsTransactionItem.h"
+#include "nsTransactionList.h"
+#include "nsTransactionManager.h"
+#include "nsTransactionStack.h"
+
+nsTransactionManager::nsTransactionManager(int32_t aMaxTransactionCount)
+  : mMaxTransactionCount(aMaxTransactionCount)
+  , mDoStack(nsTransactionStack::FOR_UNDO)
+  , mUndoStack(nsTransactionStack::FOR_UNDO)
+  , mRedoStack(nsTransactionStack::FOR_REDO)
+{
+}
+
+nsTransactionManager::~nsTransactionManager()
+{
+}
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(nsTransactionManager)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsTransactionManager)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mListeners)
+  tmp->mDoStack.DoUnlink();
+  tmp->mUndoStack.DoUnlink();
+  tmp->mRedoStack.DoUnlink();
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsTransactionManager)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mListeners)
+  tmp->mDoStack.DoTraverse(cb);
+  tmp->mUndoStack.DoTraverse(cb);
+  tmp->mRedoStack.DoTraverse(cb);
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsTransactionManager)
+  NS_INTERFACE_MAP_ENTRY(nsITransactionManager)
+  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsITransactionManager)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsTransactionManager)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsTransactionManager)
+
+NS_IMETHODIMP
+nsTransactionManager::DoTransaction(nsITransaction *aTransaction)
+{
+  NS_ENSURE_TRUE(aTransaction, NS_ERROR_NULL_POINTER);
+
+  bool doInterrupt = false;
+
+  nsresult rv = WillDoNotify(aTransaction, &doInterrupt);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (doInterrupt) {
+    return NS_OK;
+  }
+
+  rv = BeginTransaction(aTransaction, nullptr);
+  if (NS_FAILED(rv)) {
+    DidDoNotify(aTransaction, rv);
+    return rv;
+  }
+
+  rv = EndTransaction(false);
+
+  nsresult rv2 = DidDoNotify(aTransaction, rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = rv2;
+  }
+
+  // XXX The result of EndTransaction() or DidDoNotify() if EndTransaction()
+  //     succeeded.
+  return rv;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::UndoTransaction()
+{
+  // It is illegal to call UndoTransaction() while the transaction manager is
+  // executing a  transaction's DoTransaction() method! If this happens,
+  // the UndoTransaction() request is ignored, and we return NS_ERROR_FAILURE.
+  if (!mDoStack.IsEmpty()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Peek at the top of the undo stack. Don't remove the transaction
+  // until it has successfully completed.
+  RefPtr<nsTransactionItem> tx = mUndoStack.Peek();
+  if (!tx) {
+    // Bail if there's nothing on the stack.
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsITransaction> t = tx->GetTransaction();
+  bool doInterrupt = false;
+  nsresult rv = WillUndoNotify(t, &doInterrupt);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (doInterrupt) {
+    return NS_OK;
+  }
+
+  rv = tx->UndoTransaction(this);
+  if (NS_SUCCEEDED(rv)) {
+    tx = mUndoStack.Pop();
+    mRedoStack.Push(tx.forget());
+  }
+
+  nsresult rv2 = DidUndoNotify(t, rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = rv2;
+  }
+
+  // XXX The result of UndoTransaction() or DidUndoNotify() if UndoTransaction()
+  //     succeeded.
+  return rv;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::RedoTransaction()
+{
+  // It is illegal to call RedoTransaction() while the transaction manager is
+  // executing a  transaction's DoTransaction() method! If this happens,
+  // the RedoTransaction() request is ignored, and we return NS_ERROR_FAILURE.
+  if (!mDoStack.IsEmpty()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Peek at the top of the redo stack. Don't remove the transaction
+  // until it has successfully completed.
+  RefPtr<nsTransactionItem> tx = mRedoStack.Peek();
+  if (!tx) {
+    // Bail if there's nothing on the stack.
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsITransaction> t = tx->GetTransaction();
+  bool doInterrupt = false;
+  nsresult rv = WillRedoNotify(t, &doInterrupt);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (doInterrupt) {
+    return NS_OK;
+  }
+
+  rv = tx->RedoTransaction(this);
+  if (NS_SUCCEEDED(rv)) {
+    tx = mRedoStack.Pop();
+    mUndoStack.Push(tx.forget());
+  }
+
+  nsresult rv2 = DidRedoNotify(t, rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = rv2;
+  }
+
+  // XXX The result of RedoTransaction() or DidRedoNotify() if RedoTransaction()
+  //     succeeded.
+  return rv;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::Clear()
+{
+  nsresult rv = ClearRedoStack();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  return ClearUndoStack();
+}
+
+NS_IMETHODIMP
+nsTransactionManager::BeginBatch(nsISupports* aData)
+{
+  // We can batch independent transactions together by simply pushing
+  // a dummy transaction item on the do stack. This dummy transaction item
+  // will be popped off the do stack, and then pushed on the undo stack
+  // in EndBatch().
+  bool doInterrupt = false;
+  nsresult rv = WillBeginBatchNotify(&doInterrupt);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (doInterrupt) {
+    return NS_OK;
+  }
+
+  rv = BeginTransaction(0, aData);
+
+  nsresult rv2 = DidBeginBatchNotify(rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = rv2;
+  }
+
+  // XXX The result of BeginTransaction() or DidBeginBatchNotify() if
+  //     BeginTransaction() succeeded.
+  return rv;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::EndBatch(bool aAllowEmpty)
+{
+  // XXX: Need to add some mechanism to detect the case where the transaction
+  //      at the top of the do stack isn't the dummy transaction, so we can
+  //      throw an error!! This can happen if someone calls EndBatch() within
+  //      the DoTransaction() method of a transaction.
+  //
+  //      For now, we can detect this case by checking the value of the
+  //      dummy transaction's mTransaction field. If it is our dummy
+  //      transaction, it should be nullptr. This may not be true in the
+  //      future when we allow users to execute a transaction when beginning
+  //      a batch!!!!
+  RefPtr<nsTransactionItem> tx = mDoStack.Peek();
+  nsCOMPtr<nsITransaction> ti;
+  if (tx) {
+    ti = tx->GetTransaction();
+  }
+  if (!tx || ti) {
+    return NS_ERROR_FAILURE;
+  }
+
+  bool doInterrupt = false;
+  nsresult rv = WillEndBatchNotify(&doInterrupt);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (doInterrupt) {
+    return NS_OK;
+  }
+
+  rv = EndTransaction(aAllowEmpty);
+  nsresult rv2 = DidEndBatchNotify(rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = rv2;
+  }
+
+  // XXX The result of EndTransaction() or DidEndBatchNotify() if
+  //     EndTransaction() succeeded.
+  return rv;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::GetNumberOfUndoItems(int32_t *aNumItems)
+{
+  *aNumItems = mUndoStack.GetSize();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::GetNumberOfRedoItems(int32_t *aNumItems)
+{
+  *aNumItems = mRedoStack.GetSize();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::GetMaxTransactionCount(int32_t *aMaxCount)
+{
+  NS_ENSURE_TRUE(aMaxCount, NS_ERROR_NULL_POINTER);
+  *aMaxCount = mMaxTransactionCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::SetMaxTransactionCount(int32_t aMaxCount)
+{
+  // It is illegal to call SetMaxTransactionCount() while the transaction
+  // manager is executing a  transaction's DoTransaction() method because
+  // the undo and redo stacks might get pruned! If this happens, the
+  // SetMaxTransactionCount() request is ignored, and we return
+  // NS_ERROR_FAILURE.
+  if (!mDoStack.IsEmpty()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // If aMaxCount is less than zero, the user wants unlimited
+  // levels of undo! No need to prune the undo or redo stacks!
+  if (aMaxCount < 0) {
+    mMaxTransactionCount = -1;
+    return NS_OK;
+  }
+
+  // If aMaxCount is greater than the number of transactions that currently
+  // exist on the undo and redo stack, there is no need to prune the
+  // undo or redo stacks!
+  int32_t numUndoItems = mUndoStack.GetSize();
+  int32_t numRedoItems = mRedoStack.GetSize();
+  int32_t total = numUndoItems + numRedoItems;
+  if (aMaxCount > total) {
+    mMaxTransactionCount = aMaxCount;
+    return NS_OK;
+  }
+
+  // Try getting rid of some transactions on the undo stack! Start at
+  // the bottom of the stack and pop towards the top.
+  while (numUndoItems > 0 && (numRedoItems + numUndoItems) > aMaxCount) {
+    RefPtr<nsTransactionItem> tx = mUndoStack.PopBottom();
+    if (!tx) {
+      return NS_ERROR_FAILURE;
+    }
+    --numUndoItems;
+  }
+
+  // If necessary, get rid of some transactions on the redo stack! Start at
+  // the bottom of the stack and pop towards the top.
+  while (numRedoItems > 0 && (numRedoItems + numUndoItems) > aMaxCount) {
+    RefPtr<nsTransactionItem> tx = mRedoStack.PopBottom();
+    if (!tx) {
+      return NS_ERROR_FAILURE;
+    }
+    --numRedoItems;
+  }
+
+  mMaxTransactionCount = aMaxCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::PeekUndoStack(nsITransaction **aTransaction)
+{
+  MOZ_ASSERT(aTransaction);
+  *aTransaction = PeekUndoStack().take();
+  return NS_OK;
+}
+
+already_AddRefed<nsITransaction>
+nsTransactionManager::PeekUndoStack()
+{
+  RefPtr<nsTransactionItem> tx = mUndoStack.Peek();
+  if (!tx) {
+    return nullptr;
+  }
+  return tx->GetTransaction();
+}
+
+NS_IMETHODIMP
+nsTransactionManager::PeekRedoStack(nsITransaction** aTransaction)
+{
+  MOZ_ASSERT(aTransaction);
+  *aTransaction = PeekRedoStack().take();
+  return NS_OK;
+}
+
+already_AddRefed<nsITransaction>
+nsTransactionManager::PeekRedoStack()
+{
+  RefPtr<nsTransactionItem> tx = mRedoStack.Peek();
+  if (!tx) {
+    return nullptr;
+  }
+  return tx->GetTransaction();
+}
+
+NS_IMETHODIMP
+nsTransactionManager::GetUndoList(nsITransactionList **aTransactionList)
+{
+  NS_ENSURE_TRUE(aTransactionList, NS_ERROR_NULL_POINTER);
+
+  *aTransactionList = (nsITransactionList *)new nsTransactionList(this, &mUndoStack);
+  NS_IF_ADDREF(*aTransactionList);
+  return (! *aTransactionList) ? NS_ERROR_OUT_OF_MEMORY : NS_OK;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::GetRedoList(nsITransactionList **aTransactionList)
+{
+  NS_ENSURE_TRUE(aTransactionList, NS_ERROR_NULL_POINTER);
+
+  *aTransactionList = (nsITransactionList *)new nsTransactionList(this, &mRedoStack);
+  NS_IF_ADDREF(*aTransactionList);
+  return (! *aTransactionList) ? NS_ERROR_OUT_OF_MEMORY : NS_OK;
+}
+
+nsresult
+nsTransactionManager::BatchTopUndo()
+{
+  if (mUndoStack.GetSize() < 2) {
+    // Not enough transactions to merge into one batch.
+    return NS_OK;
+  }
+
+  RefPtr<nsTransactionItem> lastUndo;
+  RefPtr<nsTransactionItem> previousUndo;
+
+  lastUndo = mUndoStack.Pop();
+  MOZ_ASSERT(lastUndo, "There should be at least two transactions.");
+
+  previousUndo = mUndoStack.Peek();
+  MOZ_ASSERT(previousUndo, "There should be at least two transactions.");
+
+  nsresult rv = previousUndo->AddChild(lastUndo);
+
+  // Transfer data from the transactions that is going to be
+  // merged to the transaction that it is being merged with.
+  nsCOMArray<nsISupports>& lastData = lastUndo->GetData();
+  nsCOMArray<nsISupports>& previousData = previousUndo->GetData();
+  NS_ENSURE_TRUE(previousData.AppendObjects(lastData), NS_ERROR_UNEXPECTED);
+  lastData.Clear();
+  return rv;
+}
+
+nsresult
+nsTransactionManager::RemoveTopUndo()
+{
+  if (mUndoStack.IsEmpty()) {
+    return NS_OK;
+  }
+
+  RefPtr<nsTransactionItem> lastUndo = mUndoStack.Pop();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::AddListener(nsITransactionListener *aListener)
+{
+  NS_ENSURE_TRUE(aListener, NS_ERROR_NULL_POINTER);
+  return mListeners.AppendObject(aListener) ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::RemoveListener(nsITransactionListener *aListener)
+{
+  NS_ENSURE_TRUE(aListener, NS_ERROR_NULL_POINTER);
+  return mListeners.RemoveObject(aListener) ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::ClearUndoStack()
+{
+  mUndoStack.Clear();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTransactionManager::ClearRedoStack()
+{
+  mRedoStack.Clear();
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::WillDoNotify(nsITransaction *aTransaction, bool *aInterrupt)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->WillDo(this, aTransaction, aInterrupt);
+    if (NS_FAILED(rv) || *aInterrupt) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::DidDoNotify(nsITransaction *aTransaction, nsresult aDoResult)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->DidDo(this, aTransaction, aDoResult);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::WillUndoNotify(nsITransaction *aTransaction, bool *aInterrupt)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->WillUndo(this, aTransaction, aInterrupt);
+    if (NS_FAILED(rv) || *aInterrupt) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::DidUndoNotify(nsITransaction *aTransaction, nsresult aUndoResult)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->DidUndo(this, aTransaction, aUndoResult);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::WillRedoNotify(nsITransaction *aTransaction, bool *aInterrupt)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->WillRedo(this, aTransaction, aInterrupt);
+    if (NS_FAILED(rv) || *aInterrupt) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::DidRedoNotify(nsITransaction *aTransaction, nsresult aRedoResult)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->DidRedo(this, aTransaction, aRedoResult);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::WillBeginBatchNotify(bool *aInterrupt)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->WillBeginBatch(this, aInterrupt);
+    if (NS_FAILED(rv) || *aInterrupt) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::DidBeginBatchNotify(nsresult aResult)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->DidBeginBatch(this, aResult);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::WillEndBatchNotify(bool *aInterrupt)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->WillEndBatch(this, aInterrupt);
+    if (NS_FAILED(rv) || *aInterrupt) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::DidEndBatchNotify(nsresult aResult)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->DidEndBatch(this, aResult);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::WillMergeNotify(nsITransaction *aTop, nsITransaction *aTransaction, bool *aInterrupt)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv = listener->WillMerge(this, aTop, aTransaction, aInterrupt);
+    if (NS_FAILED(rv) || *aInterrupt) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::DidMergeNotify(nsITransaction *aTop,
+                                     nsITransaction *aTransaction,
+                                     bool aDidMerge,
+                                     nsresult aMergeResult)
+{
+  for (int32_t i = 0, lcount = mListeners.Count(); i < lcount; i++) {
+    nsITransactionListener* listener = mListeners[i];
+    NS_ENSURE_TRUE(listener, NS_ERROR_FAILURE);
+
+    nsresult rv =
+      listener->DidMerge(this, aTop, aTransaction, aDidMerge, aMergeResult);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::BeginTransaction(nsITransaction *aTransaction,
+                                       nsISupports *aData)
+{
+  // XXX: POSSIBLE OPTIMIZATION
+  //      We could use a factory that pre-allocates/recycles transaction items.
+  RefPtr<nsTransactionItem> tx = new nsTransactionItem(aTransaction);
+  if (!tx) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  if (aData) {
+    nsCOMArray<nsISupports>& data = tx->GetData();
+    data.AppendObject(aData);
+  }
+
+  mDoStack.Push(tx);
+
+  nsresult rv = tx->DoTransaction();
+  if (NS_FAILED(rv)) {
+    tx = mDoStack.Pop();
+    return rv;
+  }
+  return NS_OK;
+}
+
+nsresult
+nsTransactionManager::EndTransaction(bool aAllowEmpty)
+{
+  RefPtr<nsTransactionItem> tx = mDoStack.Pop();
+  if (!tx) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsITransaction> tint = tx->GetTransaction();
+  if (!tint && !aAllowEmpty) {
+    // If we get here, the transaction must be a dummy batch transaction
+    // created by BeginBatch(). If it contains no children, get rid of it!
+    int32_t nc = 0;
+    tx->GetNumberOfChildren(&nc);
+    if (!nc) {
+      return NS_OK;
+    }
+  }
+
+  // Check if the transaction is transient. If it is, there's nothing
+  // more to do, just return.
+  bool isTransient = false;
+  nsresult rv = NS_OK;
+  if (tint) {
+    rv = tint->GetIsTransient(&isTransient);
+  }
+  if (NS_FAILED(rv) || isTransient || !mMaxTransactionCount) {
+    // XXX: Should we be clearing the redo stack if the transaction
+    //      is transient and there is nothing on the do stack?
+    return rv;
+  }
+
+  // Check if there is a transaction on the do stack. If there is,
+  // the current transaction is a "sub" transaction, and should
+  // be added to the transaction at the top of the do stack.
+  RefPtr<nsTransactionItem> top = mDoStack.Peek();
+  if (top) {
+    return top->AddChild(tx); // XXX: What do we do if this fails?
+  }
+
+  // The transaction succeeded, so clear the redo stack.
+  rv = ClearRedoStack();
+  if (NS_FAILED(rv)) {
+    // XXX: What do we do if this fails?
+  }
+
+  // Check if we can coalesce this transaction with the one at the top
+  // of the undo stack.
+  top = mUndoStack.Peek();
+  if (tint && top) {
+    bool didMerge = false;
+    nsCOMPtr<nsITransaction> topTransaction = top->GetTransaction();
+    if (topTransaction) {
+      bool doInterrupt = false;
+      rv = WillMergeNotify(topTransaction, tint, &doInterrupt);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      if (!doInterrupt) {
+        rv = topTransaction->Merge(tint, &didMerge);
+        nsresult rv2 = DidMergeNotify(topTransaction, tint, didMerge, rv);
+        if (NS_SUCCEEDED(rv)) {
+          rv = rv2;
+        }
+        if (NS_FAILED(rv)) {
+          // XXX: What do we do if this fails?
+        }
+        if (didMerge) {
+          return rv;
+        }
+      }
+    }
+  }
+
+  // Check to see if we've hit the max level of undo. If so,
+  // pop the bottom transaction off the undo stack and release it!
+  int32_t sz = mUndoStack.GetSize();
+  if (mMaxTransactionCount > 0 && sz >= mMaxTransactionCount) {
+    RefPtr<nsTransactionItem> overflow = mUndoStack.PopBottom();
+  }
+
+  // Push the transaction on the undo stack:
+  mUndoStack.Push(tx.forget());
+  return NS_OK;
+}
diff --git a/editor/txmgr/nsTransactionManager.h b/editor/txmgr/nsTransactionManager.h
new file mode 100644
index 000000000..17d21819f
--- /dev/null
+++ b/editor/txmgr/nsTransactionManager.h
@@ -0,0 +1,83 @@
+/* -*- 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/. */
+
+#ifndef nsTransactionManager_h__
+#define nsTransactionManager_h__
+
+#include "nsCOMArray.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsTransactionStack.h"
+#include "nsISupportsImpl.h"
+#include "nsITransactionManager.h"
+#include "nsTransactionStack.h"
+#include "nsWeakReference.h"
+#include "nscore.h"
+
+class nsITransaction;
+class nsITransactionListener;
+
+/** implementation of a transaction manager object.
+ *
+ */
+class nsTransactionManager final : public nsITransactionManager
+                                 , public nsSupportsWeakReference
+{
+private:
+
+  int32_t                mMaxTransactionCount;
+  nsTransactionStack     mDoStack;
+  nsTransactionStack     mUndoStack;
+  nsTransactionStack     mRedoStack;
+  nsCOMArray<nsITransactionListener> mListeners;
+
+  /** The default destructor.
+   */
+  virtual ~nsTransactionManager();
+
+public:
+
+  /** The default constructor.
+   */
+  explicit nsTransactionManager(int32_t aMaxTransactionCount=-1);
+
+  /* Macro for AddRef(), Release(), and QueryInterface() */
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsTransactionManager,
+                                           nsITransactionManager)
+
+  /* nsITransactionManager method implementations. */
+  NS_DECL_NSITRANSACTIONMANAGER
+
+  already_AddRefed<nsITransaction> PeekUndoStack();
+  already_AddRefed<nsITransaction> PeekRedoStack();
+
+  virtual nsresult WillDoNotify(nsITransaction *aTransaction, bool *aInterrupt);
+  virtual nsresult DidDoNotify(nsITransaction *aTransaction, nsresult aExecuteResult);
+  virtual nsresult WillUndoNotify(nsITransaction *aTransaction, bool *aInterrupt);
+  virtual nsresult DidUndoNotify(nsITransaction *aTransaction, nsresult aUndoResult);
+  virtual nsresult WillRedoNotify(nsITransaction *aTransaction, bool *aInterrupt);
+  virtual nsresult DidRedoNotify(nsITransaction *aTransaction, nsresult aRedoResult);
+  virtual nsresult WillBeginBatchNotify(bool *aInterrupt);
+  virtual nsresult DidBeginBatchNotify(nsresult aResult);
+  virtual nsresult WillEndBatchNotify(bool *aInterrupt);
+  virtual nsresult DidEndBatchNotify(nsresult aResult);
+  virtual nsresult WillMergeNotify(nsITransaction *aTop,
+                                   nsITransaction *aTransaction,
+                                   bool *aInterrupt);
+  virtual nsresult DidMergeNotify(nsITransaction *aTop,
+                                  nsITransaction *aTransaction,
+                                  bool aDidMerge,
+                                  nsresult aMergeResult);
+
+private:
+
+  /* nsTransactionManager specific private methods. */
+  virtual nsresult BeginTransaction(nsITransaction *aTransaction,
+                                    nsISupports *aData);
+  virtual nsresult EndTransaction(bool aAllowEmpty);
+};
+
+#endif // nsTransactionManager_h__
diff --git a/editor/txmgr/nsTransactionManagerCID.h b/editor/txmgr/nsTransactionManagerCID.h
new file mode 100644
index 000000000..f65e98579
--- /dev/null
+++ b/editor/txmgr/nsTransactionManagerCID.h
@@ -0,0 +1,14 @@
+/* -*- 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/. */
+
+#ifndef nsTransactionManagerCID_h__
+#define nsTransactionManagerCID_h__
+
+#define NS_TRANSACTIONMANAGER_CID                   \
+{ /* 9C8F9601-801A-11d2-98BA-00805F297D89 */        \
+0x9c8f9601, 0x801a, 0x11d2,                         \
+{ 0x98, 0xba, 0x0, 0x80, 0x5f, 0x29, 0x7d, 0x89 } }
+
+#endif /* nsTransactionManagerCID_h__ */
diff --git a/editor/txmgr/nsTransactionManagerFactory.cpp b/editor/txmgr/nsTransactionManagerFactory.cpp
new file mode 100644
index 000000000..a4cbb5950
--- /dev/null
+++ b/editor/txmgr/nsTransactionManagerFactory.cpp
@@ -0,0 +1,38 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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 <stddef.h>
+
+#include "mozilla/Module.h"
+#include "mozilla/ModuleUtils.h"
+#include "nsID.h"
+#include "nsITransactionManager.h"
+#include "nsTransactionManager.h"
+#include "nsTransactionManagerCID.h"
+
+////////////////////////////////////////////////////////////////////////
+// Define the contructor function for the objects
+//
+// NOTE: This creates an instance of objects by using the default constructor
+//
+NS_GENERIC_FACTORY_CONSTRUCTOR(nsTransactionManager)
+NS_DEFINE_NAMED_CID(NS_TRANSACTIONMANAGER_CID);
+
+static const mozilla::Module::CIDEntry kTxMgrCIDs[] = {
+    { &kNS_TRANSACTIONMANAGER_CID, false, nullptr, nsTransactionManagerConstructor },
+    { nullptr }
+};
+
+static const mozilla::Module::ContractIDEntry kTxMgrContracts[] = {
+    { NS_TRANSACTIONMANAGER_CONTRACTID, &kNS_TRANSACTIONMANAGER_CID },
+    { nullptr }
+};
+
+static const mozilla::Module kTxMgrModule = {
+    mozilla::Module::kVersion,
+    kTxMgrCIDs,
+    kTxMgrContracts
+};
+NSMODULE_DEFN(nsTransactionManagerModule) = &kTxMgrModule;
diff --git a/editor/txmgr/nsTransactionStack.cpp b/editor/txmgr/nsTransactionStack.cpp
new file mode 100644
index 000000000..febfa3110
--- /dev/null
+++ b/editor/txmgr/nsTransactionStack.cpp
@@ -0,0 +1,108 @@
+/* -*- 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 "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsISupportsUtils.h"
+#include "nsTransactionItem.h"
+#include "nsTransactionStack.h"
+#include "nscore.h"
+
+class nsTransactionStackDeallocator : public nsDequeFunctor {
+  virtual void* operator() (void* aObject) {
+    RefPtr<nsTransactionItem> releaseMe = dont_AddRef(static_cast<nsTransactionItem*>(aObject));
+    return nullptr;
+  }
+};
+
+nsTransactionStack::nsTransactionStack(Type aType)
+  : nsDeque(new nsTransactionStackDeallocator())
+  , mType(aType)
+{
+}
+
+nsTransactionStack::~nsTransactionStack()
+{
+  Clear();
+}
+
+void
+nsTransactionStack::Push(nsTransactionItem* aTransactionItem)
+{
+  if (!aTransactionItem) {
+    return;
+  }
+
+  RefPtr<nsTransactionItem> item(aTransactionItem);
+  Push(item.forget());
+}
+
+void
+nsTransactionStack::Push(already_AddRefed<nsTransactionItem> aTransactionItem)
+{
+  RefPtr<nsTransactionItem> item(aTransactionItem);
+  if (!item) {
+    return;
+  }
+
+  nsDeque::Push(item.forget().take());
+}
+
+already_AddRefed<nsTransactionItem>
+nsTransactionStack::Pop()
+{
+  RefPtr<nsTransactionItem> item =
+    dont_AddRef(static_cast<nsTransactionItem*>(nsDeque::Pop()));
+  return item.forget();
+}
+
+already_AddRefed<nsTransactionItem>
+nsTransactionStack::PopBottom()
+{
+  RefPtr<nsTransactionItem> item =
+    dont_AddRef(static_cast<nsTransactionItem*>(nsDeque::PopFront()));
+  return item.forget();
+}
+
+already_AddRefed<nsTransactionItem>
+nsTransactionStack::Peek()
+{
+  RefPtr<nsTransactionItem> item =
+    static_cast<nsTransactionItem*>(nsDeque::Peek());
+  return item.forget();
+}
+
+already_AddRefed<nsTransactionItem>
+nsTransactionStack::GetItem(int32_t aIndex)
+{
+  if (aIndex < 0 || aIndex >= static_cast<int32_t>(nsDeque::GetSize())) {
+    return nullptr;
+  }
+  RefPtr<nsTransactionItem> item =
+    static_cast<nsTransactionItem*>(nsDeque::ObjectAt(aIndex));
+  return item.forget();
+}
+
+void
+nsTransactionStack::Clear()
+{
+  while (GetSize() != 0) {
+    RefPtr<nsTransactionItem> item =
+      mType == FOR_UNDO ? Pop() : PopBottom();
+  }
+}
+
+void
+nsTransactionStack::DoTraverse(nsCycleCollectionTraversalCallback &cb)
+{
+  int32_t size = GetSize();
+  for (int32_t i = 0; i < size; ++i) {
+    nsTransactionItem* item = static_cast<nsTransactionItem*>(nsDeque::ObjectAt(i));
+    if (item) {
+      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "transaction stack mDeque[i]");
+      cb.NoteNativeChild(item, NS_CYCLE_COLLECTION_PARTICIPANT(nsTransactionItem));
+    }
+  }
+}
diff --git a/editor/txmgr/nsTransactionStack.h b/editor/txmgr/nsTransactionStack.h
new file mode 100644
index 000000000..f6f6c3a2e
--- /dev/null
+++ b/editor/txmgr/nsTransactionStack.h
@@ -0,0 +1,39 @@
+/* -*- 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/. */
+
+#ifndef nsTransactionStack_h__
+#define nsTransactionStack_h__
+
+#include "nsDeque.h"
+
+class nsCycleCollectionTraversalCallback;
+class nsTransactionItem;
+
+class nsTransactionStack : private nsDeque
+{
+public:
+  enum Type { FOR_UNDO, FOR_REDO };
+
+  explicit nsTransactionStack(Type aType);
+  ~nsTransactionStack();
+
+  void Push(nsTransactionItem *aTransactionItem);
+  void Push(already_AddRefed<nsTransactionItem> aTransactionItem);
+  already_AddRefed<nsTransactionItem> Pop();
+  already_AddRefed<nsTransactionItem> PopBottom();
+  already_AddRefed<nsTransactionItem> Peek();
+  already_AddRefed<nsTransactionItem> GetItem(int32_t aIndex);
+  void Clear();
+  int32_t GetSize() const { return static_cast<int32_t>(nsDeque::GetSize()); }
+  bool IsEmpty() const { return GetSize() == 0; }
+
+  void DoUnlink() { Clear(); }
+  void DoTraverse(nsCycleCollectionTraversalCallback &cb);
+
+private:
+  const Type mType;
+};
+
+#endif // nsTransactionStack_h__
diff --git a/editor/txmgr/tests/TestTXMgr.cpp b/editor/txmgr/tests/TestTXMgr.cpp
new file mode 100644
index 000000000..4e77aae7f
--- /dev/null
+++ b/editor/txmgr/tests/TestTXMgr.cpp
@@ -0,0 +1,4478 @@
+/* -*- 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 "TestHarness.h"
+
+#include "nsITransactionManager.h"
+#include "nsComponentManagerUtils.h"
+#include "mozilla/Likely.h"
+
+static int32_t sConstructorCount     = 0;
+static int32_t sDestructorCount      = 0;
+static int32_t *sDestructorOrderArr  = 0;
+static int32_t sDoCount              = 0;
+static int32_t *sDoOrderArr          = 0;
+static int32_t sUndoCount            = 0;
+static int32_t *sUndoOrderArr        = 0;
+static int32_t sRedoCount            = 0;
+static int32_t *sRedoOrderArr        = 0;
+
+// #define ENABLE_DEBUG_PRINTFS 1
+
+int32_t sSimpleTestDestructorOrderArr[] = {
+          2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,  15,
+         16,  17,  18,  19,  20,  21,   1,  22,  23,  24,  25,  26,  27,  28,
+         29,  30,  31,  42,  43,  44,  45,  46,  47,  48,  49,  50,  51,  52,
+         53,  54,  55,  56,  57,  58,  59,  60,  61,  41,  40,  62,  39,  38,
+         37,  36,  35,  34,  33,  32,  68,  63,  64,  65,  66,  67,  69,  71,
+         70,  72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,
+         85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,  97,  98,
+         99, 100, 101, 111, 110, 109, 108, 107, 106, 105, 104, 103, 102, 131,
+        130, 129, 128, 127, 126, 125, 124, 123, 122, 121, 120, 119, 118, 117,
+        116, 115, 114, 113, 112 };
+
+int32_t sSimpleTestDoOrderArr[] = {
+          1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
+         15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,
+         29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,
+         43,  44,  45,  46,  47,  48,  49,  50,  51,  52,  53,  54,  55,  56,
+         57,  58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,
+         71,  72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,
+         85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,  97,  98,
+         99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112,
+        113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126,
+        127, 128, 129, 130, 131 };
+
+int32_t sSimpleTestUndoOrderArr[] = {
+         41,  40,  39,  38,  62,  39,  38,  37,  69,  71,  70, 111, 110, 109,
+        108, 107, 106, 105, 104, 103, 102, 131, 130, 129, 128, 127, 126, 125,
+        124, 123, 122 };
+
+static int32_t sSimpleTestRedoOrderArr[] = {
+         38,  39,  70 };
+
+int32_t sAggregateTestDestructorOrderArr[] = {
+         14,  13,  12,  11,  10,   9,   8,  21,  20,  19,  18,  17,  16,  15,
+         28,  27,  26,  25,  24,  23,  22,  35,  34,  33,  32,  31,  30,  29,
+         42,  41,  40,  39,  38,  37,  36,  49,  48,  47,  46,  45,  44,  43,
+         56,  55,  54,  53,  52,  51,  50,  63,  62,  61,  60,  59,  58,  57,
+         70,  69,  68,  67,  66,  65,  64,  77,  76,  75,  74,  73,  72,  71,
+         84,  83,  82,  81,  80,  79,  78,  91,  90,  89,  88,  87,  86,  85,
+         98,  97,  96,  95,  94,  93,  92, 105, 104, 103, 102, 101, 100,  99,
+        112, 111, 110, 109, 108, 107, 106, 119, 118, 117, 116, 115, 114, 113,
+        126, 125, 124, 123, 122, 121, 120, 133, 132, 131, 130, 129, 128, 127,
+        140, 139, 138, 137, 136, 135, 134, 147, 146, 145, 144, 143, 142, 141,
+          7,   6,   5,   4,   3,   2,   1, 154, 153, 152, 151, 150, 149, 148,
+        161, 160, 159, 158, 157, 156, 155, 168, 167, 166, 165, 164, 163, 162,
+        175, 174, 173, 172, 171, 170, 169, 182, 181, 180, 179, 178, 177, 176,
+        189, 188, 187, 186, 185, 184, 183, 196, 195, 194, 193, 192, 191, 190,
+        203, 202, 201, 200, 199, 198, 197, 210, 209, 208, 207, 206, 205, 204,
+        217, 216, 215, 214, 213, 212, 211, 294, 293, 292, 291, 290, 289, 288,
+        301, 300, 299, 298, 297, 296, 295, 308, 307, 306, 305, 304, 303, 302,
+        315, 314, 313, 312, 311, 310, 309, 322, 321, 320, 319, 318, 317, 316,
+        329, 328, 327, 326, 325, 324, 323, 336, 335, 334, 333, 332, 331, 330,
+        343, 342, 341, 340, 339, 338, 337, 350, 349, 348, 347, 346, 345, 344,
+        357, 356, 355, 354, 353, 352, 351, 364, 363, 362, 361, 360, 359, 358,
+        371, 370, 369, 368, 367, 366, 365, 378, 377, 376, 375, 374, 373, 372,
+        385, 384, 383, 382, 381, 380, 379, 392, 391, 390, 389, 388, 387, 386,
+        399, 398, 397, 396, 395, 394, 393, 406, 405, 404, 403, 402, 401, 400,
+        413, 412, 411, 410, 409, 408, 407, 420, 419, 418, 417, 416, 415, 414,
+        427, 426, 425, 424, 423, 422, 421, 287, 286, 285, 284, 283, 282, 281,
+        280, 279, 278, 277, 276, 275, 274, 434, 433, 432, 431, 430, 429, 428,
+        273, 272, 271, 270, 269, 268, 267, 266, 265, 264, 263, 262, 261, 260,
+        259, 258, 257, 256, 255, 254, 253, 252, 251, 250, 249, 248, 247, 246,
+        245, 244, 243, 242, 241, 240, 239, 238, 237, 236, 235, 234, 233, 232,
+        231, 230, 229, 228, 227, 226, 225, 224, 223, 222, 221, 220, 219, 218,
+        472, 471, 470, 441, 440, 439, 438, 437, 436, 435, 448, 447, 446, 445,
+        444, 443, 442, 455, 454, 453, 452, 451, 450, 449, 462, 461, 460, 459,
+        458, 457, 456, 469, 468, 467, 466, 465, 464, 463, 479, 478, 477, 476,
+        475, 474, 473, 493, 492, 491, 490, 489, 488, 487, 486, 485, 484, 483,
+        482, 481, 480, 496, 497, 495, 499, 500, 498, 494, 503, 504, 502, 506,
+        507, 505, 501, 510, 511, 509, 513, 514, 512, 508, 517, 518, 516, 520,
+        521, 519, 515, 524, 525, 523, 527, 528, 526, 522, 531, 532, 530, 534,
+        535, 533, 529, 538, 539, 537, 541, 542, 540, 536, 545, 546, 544, 548,
+        549, 547, 543, 552, 553, 551, 555, 556, 554, 550, 559, 560, 558, 562,
+        563, 561, 557, 566, 567, 565, 569, 570, 568, 564, 573, 574, 572, 576,
+        577, 575, 571, 580, 581, 579, 583, 584, 582, 578, 587, 588, 586, 590,
+        591, 589, 585, 594, 595, 593, 597, 598, 596, 592, 601, 602, 600, 604,
+        605, 603, 599, 608, 609, 607, 611, 612, 610, 606, 615, 616, 614, 618,
+        619, 617, 613, 622, 623, 621, 625, 626, 624, 620, 629, 630, 628, 632,
+        633, 631, 627, 640, 639, 638, 637, 636, 635, 634, 647, 646, 645, 644,
+        643, 642, 641, 654, 653, 652, 651, 650, 649, 648, 661, 660, 659, 658,
+        657, 656, 655, 668, 667, 666, 665, 664, 663, 662, 675, 674, 673, 672,
+        671, 670, 669, 682, 681, 680, 679, 678, 677, 676, 689, 688, 687, 686,
+        685, 684, 683, 696, 695, 694, 693, 692, 691, 690, 703, 702, 701, 700,
+        699, 698, 697, 773, 772, 771, 770, 769, 768, 767, 766, 765, 764, 763,
+        762, 761, 760, 759, 758, 757, 756, 755, 754, 753, 752, 751, 750, 749,
+        748, 747, 746, 745, 744, 743, 742, 741, 740, 739, 738, 737, 736, 735,
+        734, 733, 732, 731, 730, 729, 728, 727, 726, 725, 724, 723, 722, 721,
+        720, 719, 718, 717, 716, 715, 714, 713, 712, 711, 710, 709, 708, 707,
+        706, 705, 704, 913, 912, 911, 910, 909, 908, 907, 906, 905, 904, 903,
+        902, 901, 900, 899, 898, 897, 896, 895, 894, 893, 892, 891, 890, 889,
+        888, 887, 886, 885, 884, 883, 882, 881, 880, 879, 878, 877, 876, 875,
+        874, 873, 872, 871, 870, 869, 868, 867, 866, 865, 864, 863, 862, 861,
+        860, 859, 858, 857, 856, 855, 854, 853, 852, 851, 850, 849, 848, 847,
+        846, 845, 844, 843, 842, 841, 840, 839, 838, 837, 836, 835, 834, 833,
+        832, 831, 830, 829, 828, 827, 826, 825, 824, 823, 822, 821, 820, 819,
+        818, 817, 816, 815, 814, 813, 812, 811, 810, 809, 808, 807, 806, 805,
+        804, 803, 802, 801, 800, 799, 798, 797, 796, 795, 794, 793, 792, 791,
+        790, 789, 788, 787, 786, 785, 784, 783, 782, 781, 780, 779, 778, 777,
+        776, 775, 774 };
+
+int32_t sAggregateTestDoOrderArr[] = {
+          1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
+         15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,
+         29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,
+         43,  44,  45,  46,  47,  48,  49,  50,  51,  52,  53,  54,  55,  56,
+         57,  58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,
+         71,  72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,
+         85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,  97,  98,
+         99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112,
+        113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126,
+        127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140,
+        141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154,
+        155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168,
+        169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182,
+        183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196,
+        197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210,
+        211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224,
+        225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238,
+        239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252,
+        253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266,
+        267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280,
+        281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294,
+        295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308,
+        309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322,
+        323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336,
+        337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350,
+        351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364,
+        365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378,
+        379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392,
+        393, 394, 395, 396, 397, 398, 399, 400, 401, 402, 403, 404, 405, 406,
+        407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419, 420,
+        421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434,
+        435, 436, 437, 438, 439, 440, 441, 442, 443, 444, 445, 446, 447, 448,
+        449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 460, 461, 462,
+        463, 464, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476,
+        477, 478, 479, 480, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490,
+        491, 492, 493, 494, 495, 496, 497, 498, 499, 500, 501, 502, 503, 504,
+        505, 506, 507, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 518,
+        519, 520, 521, 522, 523, 524, 525, 526, 527, 528, 529, 530, 531, 532,
+        533, 534, 535, 536, 537, 538, 539, 540, 541, 542, 543, 544, 545, 546,
+        547, 548, 549, 550, 551, 552, 553, 554, 555, 556, 557, 558, 559, 560,
+        561, 562, 563, 564, 565, 566, 567, 568, 569, 570, 571, 572, 573, 574,
+        575, 576, 577, 578, 579, 580, 581, 582, 583, 584, 585, 586, 587, 588,
+        589, 590, 591, 592, 593, 594, 595, 596, 597, 598, 599, 600, 601, 602,
+        603, 604, 605, 606, 607, 608, 609, 610, 611, 612, 613, 614, 615, 616,
+        617, 618, 619, 620, 621, 622, 623, 624, 625, 626, 627, 628, 629, 630,
+        631, 632, 633, 634, 635, 636, 637, 638, 639, 640, 641, 642, 643, 644,
+        645, 646, 647, 648, 649, 650, 651, 652, 653, 654, 655, 656, 657, 658,
+        659, 660, 661, 662, 663, 664, 665, 666, 667, 668, 669, 670, 671, 672,
+        673, 674, 675, 676, 677, 678, 679, 680, 681, 682, 683, 684, 685, 686,
+        687, 688, 689, 690, 691, 692, 693, 694, 695, 696, 697, 698, 699, 700,
+        701, 702, 703, 704, 705, 706, 707, 708, 709, 710, 711, 712, 713, 714,
+        715, 716, 717, 718, 719, 720, 721, 722, 723, 724, 725, 726, 727, 728,
+        729, 730, 731, 732, 733, 734, 735, 736, 737, 738, 739, 740, 741, 742,
+        743, 744, 745, 746, 747, 748, 749, 750, 751, 752, 753, 754, 755, 756,
+        757, 758, 759, 760, 761, 762, 763, 764, 765, 766, 767, 768, 769, 770,
+        771, 772, 773, 774, 775, 776, 777, 778, 779, 780, 781, 782, 783, 784,
+        785, 786, 787, 788, 789, 790, 791, 792, 793, 794, 795, 796, 797, 798,
+        799, 800, 801, 802, 803, 804, 805, 806, 807, 808, 809, 810, 811, 812,
+        813, 814, 815, 816, 817, 818, 819, 820, 821, 822, 823, 824, 825, 826,
+        827, 828, 829, 830, 831, 832, 833, 834, 835, 836, 837, 838, 839, 840,
+        841, 842, 843, 844, 845, 846, 847, 848, 849, 850, 851, 852, 853, 854,
+        855, 856, 857, 858, 859, 860, 861, 862, 863, 864, 865, 866, 867, 868,
+        869, 870, 871, 872, 873, 874, 875, 876, 877, 878, 879, 880, 881, 882,
+        883, 884, 885, 886, 887, 888, 889, 890, 891, 892, 893, 894, 895, 896,
+        897, 898, 899, 900, 901, 902, 903, 904, 905, 906, 907, 908, 909, 910,
+        911, 912, 913 };
+
+int32_t sAggregateTestUndoOrderArr[] = {
+        287, 286, 285, 284, 283, 282, 281, 280, 279, 278, 277, 276, 275, 274,
+        273, 272, 271, 270, 269, 268, 267, 266, 265, 264, 263, 262, 261, 260,
+        434, 433, 432, 431, 430, 429, 428, 273, 272, 271, 270, 269, 268, 267,
+        266, 265, 264, 263, 262, 261, 260, 259, 258, 257, 256, 255, 254, 253,
+        479, 478, 477, 476, 475, 493, 492, 491, 490, 489, 488, 487, 486, 485,
+        484, 483, 482, 481, 480, 485, 484, 483, 482, 481, 480, 773, 772, 771,
+        770, 769, 768, 767, 766, 765, 764, 763, 762, 761, 760, 759, 758, 757,
+        756, 755, 754, 753, 752, 751, 750, 749, 748, 747, 746, 745, 744, 743,
+        742, 741, 740, 739, 738, 737, 736, 735, 734, 733, 732, 731, 730, 729,
+        728, 727, 726, 725, 724, 723, 722, 721, 720, 719, 718, 717, 716, 715,
+        714, 713, 712, 711, 710, 709, 708, 707, 706, 705, 704, 913, 912, 911,
+        910, 909, 908, 907, 906, 905, 904, 903, 902, 901, 900, 899, 898, 897,
+        896, 895, 894, 893, 892, 891, 890, 889, 888, 887, 886, 885, 884, 883,
+        882, 881, 880, 879, 878, 877, 876, 875, 874, 873, 872, 871, 870, 869,
+        868, 867, 866, 865, 864, 863, 862, 861, 860, 859, 858, 857, 856, 855,
+        854, 853, 852, 851, 850, 849, 848, 847, 846, 845, 844 };
+
+int32_t sAggregateTestRedoOrderArr[] = {
+        260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273,
+        476, 477, 478, 479, 480, 481, 482, 483, 484, 485, 486 };
+
+int32_t sSimpleBatchTestDestructorOrderArr[] = {
+         21,  22,  23,  24,  25,  26,  27,  28,  29,  30,  31,  32,  33,  34,
+         35,  36,  37,  38,  39,  40,  43,  42,  41,  64,  63,  62,  61,  60,
+         59,  58,  57,  56,  55,  54,  53,  52,  51,  50,  49,  48,  47,  46,
+         45,  44,  20,  19,  18,  17,  16,  15,  14,  13,  12,  11,  10,   9,
+          8,   7,   6,   5,   4,   3,   2,   1,  65,  67,  66,  68,  69,  70,
+         71,  72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,
+         85,  86,  87, 107, 106, 105, 104, 103, 102, 101, 100,  99,  98,  97,
+         96,  95,  94,  93,  92,  91,  90,  89,  88 };
+
+int32_t sSimpleBatchTestDoOrderArr[] = {
+          1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
+         15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,
+         29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,
+         43,  44,  45,  46,  47,  48,  49,  50,  51,  52,  53,  54,  55,  56,
+         57,  58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,
+         71,  72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,
+         85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,  97,  98,
+         99, 100, 101, 102, 103, 104, 105, 106, 107 };
+
+int32_t sSimpleBatchTestUndoOrderArr[] = {
+         43,  42,  41,  20,  19,  18,  17,  16,  15,  14,  13,  12,  11,  10,
+          9,   8,   7,   6,   5,   4,   3,   2,   1,  43,  42,  41,  63,  62,
+         61,  60,  59,  58,  57,  56,  55,  54,  53,  52,  51,  50,  49,  48,
+         47,  46,  45,  44,  65,  67,  66, 107, 106, 105, 104, 103, 102, 101,
+        100,  99,  98 };
+
+int32_t sSimpleBatchTestRedoOrderArr[] = {
+          1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
+         15,  16,  17,  18,  19,  20,  41,  42,  43,  66 };
+
+int32_t sAggregateBatchTestDestructorOrderArr[] = {
+        147, 146, 145, 144, 143, 142, 141, 154, 153, 152, 151, 150, 149, 148,
+        161, 160, 159, 158, 157, 156, 155, 168, 167, 166, 165, 164, 163, 162,
+        175, 174, 173, 172, 171, 170, 169, 182, 181, 180, 179, 178, 177, 176,
+        189, 188, 187, 186, 185, 184, 183, 196, 195, 194, 193, 192, 191, 190,
+        203, 202, 201, 200, 199, 198, 197, 210, 209, 208, 207, 206, 205, 204,
+        217, 216, 215, 214, 213, 212, 211, 224, 223, 222, 221, 220, 219, 218,
+        231, 230, 229, 228, 227, 226, 225, 238, 237, 236, 235, 234, 233, 232,
+        245, 244, 243, 242, 241, 240, 239, 252, 251, 250, 249, 248, 247, 246,
+        259, 258, 257, 256, 255, 254, 253, 266, 265, 264, 263, 262, 261, 260,
+        273, 272, 271, 270, 269, 268, 267, 280, 279, 278, 277, 276, 275, 274,
+        301, 300, 299, 298, 297, 296, 295, 294, 293, 292, 291, 290, 289, 288,
+        287, 286, 285, 284, 283, 282, 281, 444, 443, 442, 441, 440, 439, 438,
+        437, 436, 435, 434, 433, 432, 431, 430, 429, 428, 427, 426, 425, 424,
+        423, 422, 421, 420, 419, 418, 417, 416, 415, 414, 413, 412, 411, 410,
+        409, 408, 407, 406, 405, 404, 403, 402, 401, 400, 399, 398, 397, 396,
+        395, 394, 393, 392, 391, 390, 389, 388, 387, 386, 385, 384, 383, 382,
+        381, 380, 379, 378, 377, 376, 375, 374, 373, 372, 371, 370, 369, 368,
+        367, 366, 365, 364, 363, 362, 361, 360, 359, 358, 357, 356, 355, 354,
+        353, 352, 351, 350, 349, 348, 347, 346, 345, 344, 343, 342, 341, 340,
+        339, 338, 337, 336, 335, 334, 333, 332, 331, 330, 329, 328, 327, 326,
+        325, 324, 323, 322, 321, 320, 319, 318, 317, 316, 315, 314, 313, 312,
+        311, 310, 309, 308, 307, 306, 305, 304, 303, 302, 140, 139, 138, 137,
+        136, 135, 134, 133, 132, 131, 130, 129, 128, 127, 126, 125, 124, 123,
+        122, 121, 120, 119, 118, 117, 116, 115, 114, 113, 112, 111, 110, 109,
+        108, 107, 106, 105, 104, 103, 102, 101, 100,  99,  98,  97,  96,  95,
+         94,  93,  92,  91,  90,  89,  88,  87,  86,  85,  84,  83,  82,  81,
+         80,  79,  78,  77,  76,  75,  74,  73,  72,  71,  70,  69,  68,  67,
+         66,  65,  64,  63,  62,  61,  60,  59,  58,  57,  56,  55,  54,  53,
+         52,  51,  50,  49,  48,  47,  46,  45,  44,  43,  42,  41,  40,  39,
+         38,  37,  36,  35,  34,  33,  32,  31,  30,  29,  28,  27,  26,  25,
+         24,  23,  22,  21,  20,  19,  18,  17,  16,  15,  14,  13,  12,  11,
+         10,   9,   8,   7,   6,   5,   4,   3,   2,   1, 451, 450, 449, 448,
+        447, 446, 445, 465, 464, 463, 462, 461, 460, 459, 458, 457, 456, 455,
+        454, 453, 452, 468, 469, 467, 471, 472, 470, 466, 475, 476, 474, 478,
+        479, 477, 473, 482, 483, 481, 485, 486, 484, 480, 489, 490, 488, 492,
+        493, 491, 487, 496, 497, 495, 499, 500, 498, 494, 503, 504, 502, 506,
+        507, 505, 501, 510, 511, 509, 513, 514, 512, 508, 517, 518, 516, 520,
+        521, 519, 515, 524, 525, 523, 527, 528, 526, 522, 531, 532, 530, 534,
+        535, 533, 529, 538, 539, 537, 541, 542, 540, 536, 545, 546, 544, 548,
+        549, 547, 543, 552, 553, 551, 555, 556, 554, 550, 559, 560, 558, 562,
+        563, 561, 557, 566, 567, 565, 569, 570, 568, 564, 573, 574, 572, 576,
+        577, 575, 571, 580, 581, 579, 583, 584, 582, 578, 587, 588, 586, 590,
+        591, 589, 585, 594, 595, 593, 597, 598, 596, 592, 601, 602, 600, 604,
+        605, 603, 599, 745, 744, 743, 742, 741, 740, 739, 738, 737, 736, 735,
+        734, 733, 732, 731, 730, 729, 728, 727, 726, 725, 724, 723, 722, 721,
+        720, 719, 718, 717, 716, 715, 714, 713, 712, 711, 710, 709, 708, 707,
+        706, 705, 704, 703, 702, 701, 700, 699, 698, 697, 696, 695, 694, 693,
+        692, 691, 690, 689, 688, 687, 686, 685, 684, 683, 682, 681, 680, 679,
+        678, 677, 676, 675, 674, 673, 672, 671, 670, 669, 668, 667, 666, 665,
+        664, 663, 662, 661, 660, 659, 658, 657, 656, 655, 654, 653, 652, 651,
+        650, 649, 648, 647, 646, 645, 644, 643, 642, 641, 640, 639, 638, 637,
+        636, 635, 634, 633, 632, 631, 630, 629, 628, 627, 626, 625, 624, 623,
+        622, 621, 620, 619, 618, 617, 616, 615, 614, 613, 612, 611, 610, 609,
+        608, 607, 606 };
+
+int32_t sAggregateBatchTestDoOrderArr[] = {
+          1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
+         15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,
+         29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,
+         43,  44,  45,  46,  47,  48,  49,  50,  51,  52,  53,  54,  55,  56,
+         57,  58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,
+         71,  72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,
+         85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,  97,  98,
+         99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112,
+        113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126,
+        127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140,
+        141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154,
+        155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168,
+        169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182,
+        183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196,
+        197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210,
+        211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224,
+        225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238,
+        239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252,
+        253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266,
+        267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280,
+        281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294,
+        295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308,
+        309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322,
+        323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336,
+        337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350,
+        351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364,
+        365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378,
+        379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392,
+        393, 394, 395, 396, 397, 398, 399, 400, 401, 402, 403, 404, 405, 406,
+        407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419, 420,
+        421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434,
+        435, 436, 437, 438, 439, 440, 441, 442, 443, 444, 445, 446, 447, 448,
+        449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 460, 461, 462,
+        463, 464, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476,
+        477, 478, 479, 480, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490,
+        491, 492, 493, 494, 495, 496, 497, 498, 499, 500, 501, 502, 503, 504,
+        505, 506, 507, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 518,
+        519, 520, 521, 522, 523, 524, 525, 526, 527, 528, 529, 530, 531, 532,
+        533, 534, 535, 536, 537, 538, 539, 540, 541, 542, 543, 544, 545, 546,
+        547, 548, 549, 550, 551, 552, 553, 554, 555, 556, 557, 558, 559, 560,
+        561, 562, 563, 564, 565, 566, 567, 568, 569, 570, 571, 572, 573, 574,
+        575, 576, 577, 578, 579, 580, 581, 582, 583, 584, 585, 586, 587, 588,
+        589, 590, 591, 592, 593, 594, 595, 596, 597, 598, 599, 600, 601, 602,
+        603, 604, 605, 606, 607, 608, 609, 610, 611, 612, 613, 614, 615, 616,
+        617, 618, 619, 620, 621, 622, 623, 624, 625, 626, 627, 628, 629, 630,
+        631, 632, 633, 634, 635, 636, 637, 638, 639, 640, 641, 642, 643, 644,
+        645, 646, 647, 648, 649, 650, 651, 652, 653, 654, 655, 656, 657, 658,
+        659, 660, 661, 662, 663, 664, 665, 666, 667, 668, 669, 670, 671, 672,
+        673, 674, 675, 676, 677, 678, 679, 680, 681, 682, 683, 684, 685, 686,
+        687, 688, 689, 690, 691, 692, 693, 694, 695, 696, 697, 698, 699, 700,
+        701, 702, 703, 704, 705, 706, 707, 708, 709, 710, 711, 712, 713, 714,
+        715, 716, 717, 718, 719, 720, 721, 722, 723, 724, 725, 726, 727, 728,
+        729, 730, 731, 732, 733, 734, 735, 736, 737, 738, 739, 740, 741, 742,
+        743, 744, 745 };
+
+int32_t sAggregateBatchTestUndoOrderArr[] = {
+        301, 300, 299, 298, 297, 296, 295, 294, 293, 292, 291, 290, 289, 288,
+        287, 286, 285, 284, 283, 282, 281, 140, 139, 138, 137, 136, 135, 134,
+        133, 132, 131, 130, 129, 128, 127, 126, 125, 124, 123, 122, 121, 120,
+        119, 118, 117, 116, 115, 114, 113, 112, 111, 110, 109, 108, 107, 106,
+        105, 104, 103, 102, 101, 100,  99,  98,  97,  96,  95,  94,  93,  92,
+         91,  90,  89,  88,  87,  86,  85,  84,  83,  82,  81,  80,  79,  78,
+         77,  76,  75,  74,  73,  72,  71,  70,  69,  68,  67,  66,  65,  64,
+         63,  62,  61,  60,  59,  58,  57,  56,  55,  54,  53,  52,  51,  50,
+         49,  48,  47,  46,  45,  44,  43,  42,  41,  40,  39,  38,  37,  36,
+         35,  34,  33,  32,  31,  30,  29,  28,  27,  26,  25,  24,  23,  22,
+         21,  20,  19,  18,  17,  16,  15,  14,  13,  12,  11,  10,   9,   8,
+          7,   6,   5,   4,   3,   2,   1, 301, 300, 299, 298, 297, 296, 295,
+        294, 293, 292, 291, 290, 289, 288, 287, 286, 285, 284, 283, 282, 281,
+        441, 440, 439, 438, 437, 436, 435, 434, 433, 432, 431, 430, 429, 428,
+        427, 426, 425, 424, 423, 422, 421, 420, 419, 418, 417, 416, 415, 414,
+        413, 412, 411, 410, 409, 408, 407, 406, 405, 404, 403, 402, 401, 400,
+        399, 398, 397, 396, 395, 394, 393, 392, 391, 390, 389, 388, 387, 386,
+        385, 384, 383, 382, 381, 380, 379, 378, 377, 376, 375, 374, 373, 372,
+        371, 370, 369, 368, 367, 366, 365, 364, 363, 362, 361, 360, 359, 358,
+        357, 356, 355, 354, 353, 352, 351, 350, 349, 348, 347, 346, 345, 344,
+        343, 342, 341, 340, 339, 338, 337, 336, 335, 334, 333, 332, 331, 330,
+        329, 328, 327, 326, 325, 324, 323, 322, 321, 320, 319, 318, 317, 316,
+        315, 314, 313, 312, 311, 310, 309, 308, 307, 306, 305, 304, 303, 302,
+        451, 450, 449, 448, 447, 465, 464, 463, 462, 461, 460, 459, 458, 457,
+        456, 455, 454, 453, 452, 457, 456, 455, 454, 453, 452, 745, 744, 743,
+        742, 741, 740, 739, 738, 737, 736, 735, 734, 733, 732, 731, 730, 729,
+        728, 727, 726, 725, 724, 723, 722, 721, 720, 719, 718, 717, 716, 715,
+        714, 713, 712, 711, 710, 709, 708, 707, 706, 705, 704, 703, 702, 701,
+        700, 699, 698, 697, 696, 695, 694, 693, 692, 691, 690, 689, 688, 687,
+        686, 685, 684, 683, 682, 681, 680, 679, 678, 677, 676 };
+
+int32_t sAggregateBatchTestRedoOrderArr[] = {
+          1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
+         15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,
+         29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,
+         43,  44,  45,  46,  47,  48,  49,  50,  51,  52,  53,  54,  55,  56,
+         57,  58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,
+         71,  72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,
+         85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,  97,  98,
+         99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112,
+        113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126,
+        127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140,
+        281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294,
+        295, 296, 297, 298, 299, 300, 301, 448, 449, 450, 451, 452, 453, 454,
+        455, 456, 457, 458 };
+
+#define TEST_TXMGR_IF_RELEASE(tx) if (tx) tx->Release(); // Release but don't clear pointer!
+
+class TestTransaction : public nsITransaction
+{
+protected:
+  virtual ~TestTransaction() {}
+
+public:
+
+  TestTransaction() {}
+
+  NS_DECL_ISUPPORTS
+};
+
+NS_IMPL_ISUPPORTS(TestTransaction, nsITransaction)
+
+class SimpleTransaction : public TestTransaction
+{
+protected:
+
+#define NONE_FLAG               0
+#define THROWS_DO_ERROR_FLAG    1
+#define THROWS_UNDO_ERROR_FLAG  2
+#define THROWS_REDO_ERROR_FLAG  4
+#define MERGE_FLAG              8
+#define TRANSIENT_FLAG         16
+#define BATCH_FLAG             32
+#define ALL_ERROR_FLAGS        (THROWS_DO_ERROR_FLAG|THROWS_UNDO_ERROR_FLAG|THROWS_REDO_ERROR_FLAG)
+
+  int32_t mVal;
+  int32_t mFlags;
+
+public:
+
+  explicit SimpleTransaction(int32_t aFlags=NONE_FLAG)
+    : mVal(++sConstructorCount), mFlags(aFlags)
+  {}
+
+  virtual ~SimpleTransaction()
+  {
+    //
+    // Make sure transactions are being destroyed in the order we expect!
+    // Notice that we don't check to see if we go past the end of the array.
+    // This is done on purpose since we want to crash if the order array is out
+    // of date.
+    //
+    /* Disabled because the current cycle collector doesn't delete
+       cycle collectable objects synchronously, nor doesn't guarantee any order.
+    if (sDestructorOrderArr && mVal != sDestructorOrderArr[sDestructorCount]) {
+      fail("~SimpleTransaction expected %d got %d.\n",
+           mVal, sDestructorOrderArr[sDestructorCount]);
+      exit(-1);
+    }
+    */
+
+    ++sDestructorCount;
+
+#ifdef ENABLE_DEBUG_PRINTFS
+    printf("\n~SimpleTransaction: %d - 0x%.8x\n", mVal, (int32_t)this);
+#endif // ENABLE_DEBUG_PRINTFS
+
+    mVal = -1;
+  }
+
+  NS_IMETHOD DoTransaction()
+  {
+    //
+    // Make sure DoTransaction() is called in the order we expect!
+    // Notice that we don't check to see if we go past the end of the array.
+    // This is done on purpose since we want to crash if the order array is out
+    // of date.
+    //
+    if (sDoOrderArr && mVal != sDoOrderArr[sDoCount]) {
+      fail("DoTransaction expected %d got %d.\n",
+           mVal, sDoOrderArr[sDoCount]);
+      exit(-1);
+    }
+
+    ++sDoCount;
+
+#ifdef ENABLE_DEBUG_PRINTFS
+    printf("\nSimpleTransaction.DoTransaction: %d - 0x%.8x\n", mVal, (int32_t)this);
+#endif // ENABLE_DEBUG_PRINTFS
+
+    return (mFlags & THROWS_DO_ERROR_FLAG) ? NS_ERROR_FAILURE : NS_OK;
+  }
+
+  NS_IMETHOD UndoTransaction()
+  {
+    //
+    // Make sure UndoTransaction() is called in the order we expect!
+    // Notice that we don't check to see if we go past the end of the array.
+    // This is done on purpose since we want to crash if the order array is out
+    // of date.
+    //
+    if (sUndoOrderArr && mVal != sUndoOrderArr[sUndoCount]) {
+      fail("UndoTransaction expected %d got %d.\n",
+           mVal, sUndoOrderArr[sUndoCount]);
+      exit(-1);
+    }
+
+    ++sUndoCount;
+
+#ifdef ENABLE_DEBUG_PRINTFS
+    printf("\nSimpleTransaction.Undo: %d - 0x%.8x\n", mVal, (int32_t)this);
+#endif // ENABLE_DEBUG_PRINTFS
+
+    return (mFlags & THROWS_UNDO_ERROR_FLAG) ? NS_ERROR_FAILURE : NS_OK;
+  }
+
+  NS_IMETHOD RedoTransaction()
+  {
+    //
+    // Make sure RedoTransaction() is called in the order we expect!
+    // Notice that we don't check to see if we go past the end of the array.
+    // This is done on purpose since we want to crash if the order array is out
+    // of date.
+    //
+    if (sRedoOrderArr && mVal != sRedoOrderArr[sRedoCount]) {
+      fail("RedoTransaction expected %d got %d.\n",
+           mVal, sRedoOrderArr[sRedoCount]);
+      exit(-1);
+    }
+
+    ++sRedoCount;
+
+#ifdef ENABLE_DEBUG_PRINTFS
+    printf("\nSimpleTransaction.Redo: %d - 0x%.8x\n", mVal, (int32_t)this);
+#endif // ENABLE_DEBUG_PRINTFS
+
+    return (mFlags & THROWS_REDO_ERROR_FLAG) ? NS_ERROR_FAILURE : NS_OK;
+  }
+
+  NS_IMETHOD GetIsTransient(bool *aIsTransient)
+  {
+    if (aIsTransient) {
+      *aIsTransient = (mFlags & TRANSIENT_FLAG) ? true : false;
+    }
+    return NS_OK;
+  }
+
+  NS_IMETHOD Merge(nsITransaction *aTransaction, bool *aDidMerge)
+  {
+    if (aDidMerge) {
+      *aDidMerge = (mFlags & MERGE_FLAG) ? true : false;
+    }
+    return NS_OK;
+  }
+};
+
+class AggregateTransaction : public SimpleTransaction
+{
+private:
+
+  AggregateTransaction(nsITransactionManager *aTXMgr, int32_t aLevel,
+                       int32_t aNumber, int32_t aMaxLevel,
+                       int32_t aNumChildrenPerNode,
+                       int32_t aFlags)
+  {
+    mLevel              = aLevel;
+    mNumber             = aNumber;
+    mTXMgr              = aTXMgr;
+    mFlags              = aFlags & (~ALL_ERROR_FLAGS);
+    mErrorFlags         = aFlags & ALL_ERROR_FLAGS;
+    mTXMgr              = aTXMgr;
+    mMaxLevel           = aMaxLevel;
+    mNumChildrenPerNode = aNumChildrenPerNode;
+  }
+
+  nsITransactionManager *mTXMgr;
+
+  int32_t mLevel;
+  int32_t mNumber;
+  int32_t mErrorFlags;
+
+  int32_t mMaxLevel;
+  int32_t mNumChildrenPerNode;
+
+public:
+
+  AggregateTransaction(nsITransactionManager *aTXMgr,
+                       int32_t aMaxLevel, int32_t aNumChildrenPerNode,
+                       int32_t aFlags=NONE_FLAG)
+  {
+    mLevel              = 1;
+    mNumber             = 1;
+    mFlags              = aFlags & (~ALL_ERROR_FLAGS);
+    mErrorFlags         = aFlags & ALL_ERROR_FLAGS;
+    mTXMgr              = aTXMgr;
+    mMaxLevel           = aMaxLevel;
+    mNumChildrenPerNode = aNumChildrenPerNode;
+  }
+
+  virtual ~AggregateTransaction()
+  {
+    // printf("~AggregateTransaction(0x%.8x) - %3d (%3d)\n", this, mLevel, mVal);
+  }
+
+  NS_IMETHOD DoTransaction()
+  {
+    if (mLevel >= mMaxLevel) {
+      // Only leaf nodes can throw errors!
+      mFlags |= mErrorFlags;
+    }
+
+    nsresult rv = SimpleTransaction::DoTransaction();
+    if (NS_FAILED(rv)) {
+      // fail("QueryInterface() failed for transaction level %d. (%d)\n",
+      //      mLevel, rv);
+      return rv;
+    }
+
+    if (mLevel >= mMaxLevel) {
+      return NS_OK;
+    }
+
+    if (mFlags & BATCH_FLAG) {
+      rv = mTXMgr->BeginBatch(nullptr);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+    }
+
+    int32_t cLevel = mLevel + 1;
+
+    for (int i = 1; i <= mNumChildrenPerNode; i++) {
+      int32_t flags = mErrorFlags & THROWS_DO_ERROR_FLAG;
+
+      if ((mErrorFlags & THROWS_REDO_ERROR_FLAG) && i == mNumChildrenPerNode) {
+        // Make the rightmost leaf transaction throw the error!
+        flags = THROWS_REDO_ERROR_FLAG;
+        mErrorFlags = mErrorFlags & (~THROWS_REDO_ERROR_FLAG);
+      } else if ((mErrorFlags & THROWS_UNDO_ERROR_FLAG) && i == 1) {
+        // Make the leftmost leaf transaction throw the error!
+        flags = THROWS_UNDO_ERROR_FLAG;
+        mErrorFlags = mErrorFlags & (~THROWS_UNDO_ERROR_FLAG);
+      }
+
+      flags |= mFlags & BATCH_FLAG;
+
+      AggregateTransaction *tximpl =
+              new AggregateTransaction(mTXMgr, cLevel, i, mMaxLevel,
+                                       mNumChildrenPerNode, flags);
+
+      if (!tximpl) {
+        fail("Failed to allocate AggregateTransaction %d, level %d. (%d)\n",
+             i, mLevel, rv);
+
+        if (mFlags & BATCH_FLAG) {
+          mTXMgr->EndBatch(false);
+        }
+
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+
+      nsITransaction *tx = 0;
+      rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+      if (NS_FAILED(rv)) {
+        fail("QueryInterface() failed for transaction %d, level %d. (%d)\n",
+             i, mLevel, rv);
+
+        if (mFlags & BATCH_FLAG) {
+          mTXMgr->EndBatch(false);
+        }
+        return rv;
+      }
+
+      rv = mTXMgr->DoTransaction(tx);
+      if (NS_FAILED(rv)) {
+        // fail("Failed to execute transaction %d, level %d. (%d)\n",
+        //      i, mLevel, rv);
+        tx->Release();
+        if (mFlags & BATCH_FLAG) {
+          mTXMgr->EndBatch(false);
+        }
+        return rv;
+      }
+      tx->Release();
+    }
+
+    if (mFlags & BATCH_FLAG) {
+      mTXMgr->EndBatch(false);
+    }
+    return rv;
+  }
+};
+
+class TestTransactionFactory
+{
+public:
+  virtual TestTransaction *create(nsITransactionManager *txmgr, int32_t flags) = 0;
+};
+
+class SimpleTransactionFactory : public TestTransactionFactory
+{
+public:
+
+  TestTransaction *create(nsITransactionManager *txmgr, int32_t flags)
+  {
+    return (TestTransaction *)new SimpleTransaction(flags);
+  }
+};
+
+class AggregateTransactionFactory : public TestTransactionFactory
+{
+private:
+
+  int32_t mMaxLevel;
+  int32_t mNumChildrenPerNode;
+  int32_t mFixedFlags;
+
+public:
+
+  AggregateTransactionFactory(int32_t aMaxLevel, int32_t aNumChildrenPerNode,
+                              int32_t aFixedFlags=NONE_FLAG)
+      : mMaxLevel(aMaxLevel), mNumChildrenPerNode(aNumChildrenPerNode),
+        mFixedFlags(aFixedFlags)
+  {
+  }
+
+  virtual TestTransaction *create(nsITransactionManager *txmgr, int32_t flags)
+  {
+    return (TestTransaction *)new AggregateTransaction(txmgr, mMaxLevel,
+                                                       mNumChildrenPerNode,
+                                                       flags | mFixedFlags);
+  }
+};
+
+void
+reset_globals()
+{
+  sConstructorCount   = 0;
+
+  sDestructorCount    = 0;
+  sDestructorOrderArr = 0;
+
+  sDoCount            = 0;
+  sDoOrderArr         = 0;
+
+  sUndoCount          = 0;
+  sUndoOrderArr       = 0;
+
+  sRedoCount          = 0;
+  sRedoOrderArr       = 0;
+}
+
+/**
+ * Test behaviors in non-batch mode.
+ **/
+nsresult
+quick_test(TestTransactionFactory *factory)
+{
+  /*******************************************************************
+   *
+   * Create a transaction manager implementation:
+   *
+   *******************************************************************/
+
+  nsresult rv;
+  nsCOMPtr<nsITransactionManager> mgr =
+    do_CreateInstance(NS_TRANSACTIONMANAGER_CONTRACTID, &rv);
+  if (NS_FAILED(rv) || !mgr) {
+    fail("Failed to create Transaction Manager instance.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  passed("Create transaction manager instance");
+
+  /*******************************************************************
+   *
+   * Call DoTransaction() with a null transaction:
+   *
+   *******************************************************************/
+
+  rv = mgr->DoTransaction(0);
+  if (rv != NS_ERROR_NULL_POINTER) {
+    fail("DoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Call DoTransaction() with null transaction");
+
+  /*******************************************************************
+   *
+   * Call UndoTransaction() with an empty undo stack:
+   *
+   *******************************************************************/
+
+  rv = mgr->UndoTransaction();
+  if (NS_FAILED(rv)) {
+    fail("Undo on empty undo stack failed. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Call UndoTransaction() with empty undo stack");
+
+  /*******************************************************************
+   *
+   * Call RedoTransaction() with an empty redo stack:
+   *
+   *******************************************************************/
+
+  rv = mgr->RedoTransaction();
+  if (NS_FAILED(rv)) {
+    fail("Redo on empty redo stack failed. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Call RedoTransaction() with empty redo stack");
+
+  /*******************************************************************
+   *
+   * Call SetMaxTransactionCount(-1) with empty undo and redo stacks:
+   *
+   *******************************************************************/
+
+  rv = mgr->SetMaxTransactionCount(-1);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(-1) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Call SetMaxTransactionCount(-1) with empty undo and redo stacks");
+
+  /*******************************************************************
+   *
+   * Call SetMaxTransactionCount(0) with empty undo and redo stacks:
+   *
+   *******************************************************************/
+
+  rv = mgr->SetMaxTransactionCount(0);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(0) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Call SetMaxTransactionCount(0) with empty undo and redo stacks");
+
+  /*******************************************************************
+   *
+   * Call SetMaxTransactionCount(10) with empty undo and redo stacks:
+   *
+   *******************************************************************/
+
+  rv = mgr->SetMaxTransactionCount(10);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(10) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Call SetMaxTransactionCount(10) with empty undo and redo stacks");
+
+  /*******************************************************************
+   *
+   * Call Clear() with empty undo and redo stacks:
+   *
+   *******************************************************************/
+
+  rv = mgr->Clear();
+  if (NS_FAILED(rv)) {
+    fail("Clear on empty undo and redo stack failed. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Call Clear() with empty undo and redo stack");
+
+  int32_t numitems;
+
+  /*******************************************************************
+   *
+   * Call GetNumberOfUndoItems() with an empty undo stack:
+   *
+   *******************************************************************/
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Call GetNumberOfUndoItems() with empty undo stack");
+
+  /*******************************************************************
+   *
+   * Call GetNumberOfRedoItems() with an empty redo stack:
+   *
+   *******************************************************************/
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Call GetNumberOfRedoItems() with empty redo stack");
+
+  nsITransaction *tx;
+
+  /*******************************************************************
+   *
+   * Call PeekUndoStack() with an empty undo stack:
+   *
+   *******************************************************************/
+
+  tx = 0;
+  rv = mgr->PeekUndoStack(&tx);
+
+  TEST_TXMGR_IF_RELEASE(tx); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("PeekUndoStack() on empty undo stack failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (tx) {
+    fail("PeekUndoStack() on empty undo stack failed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Call PeekUndoStack() with empty undo stack");
+
+  /*******************************************************************
+   *
+   * Call PeekRedoStack() with an empty undo stack:
+   *
+   *******************************************************************/
+
+  tx = 0;
+  rv = mgr->PeekRedoStack(&tx);
+
+  TEST_TXMGR_IF_RELEASE(tx); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("PeekRedoStack() on empty redo stack failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (tx) {
+    fail("PeekRedoStack() on empty redo stack failed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Call PeekRedoStack() with empty undo stack");
+
+  /*******************************************************************
+   *
+   * Call AddListener() with a null listener pointer:
+   *
+   *******************************************************************/
+
+  rv = mgr->AddListener(0);
+  if (rv != NS_ERROR_NULL_POINTER) {
+    fail("AddListener() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Call AddListener() with null listener");
+
+  /*******************************************************************
+   *
+   * Call RemoveListener() with a null listener pointer:
+   *
+   *******************************************************************/
+
+  rv = mgr->RemoveListener(0);
+  if (rv != NS_ERROR_NULL_POINTER) {
+    fail("RemoveListener() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Call RemoveListener() with null listener");
+
+  int32_t i;
+  TestTransaction *tximpl;
+  nsITransaction *u1, *u2;
+  nsITransaction *r1, *r2;
+
+  /*******************************************************************
+   *
+   * Test coalescing by executing a transaction that can merge any
+   * command into itself. Then execute 20 transaction. Afterwards,
+   * we should still have the first transaction sitting on the undo
+   * stack. Then clear the undo and redo stacks.
+   *
+   *******************************************************************/
+
+  rv = mgr->SetMaxTransactionCount(10);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(10) failed. (%d)\n", rv);
+    return rv;
+  }
+
+
+  tximpl = factory->create(mgr, MERGE_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate initial transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for initial transaction. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("Failed to execute initial transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != tx) {
+    fail("Top of undo stack is different!. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->Clear();
+  if (NS_FAILED(rv)) {
+    fail("Clear() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Test coalescing of transactions");
+
+  /*******************************************************************
+   *
+   * Execute 20 transactions. Afterwards, we should have 10
+   * transactions on the undo stack:
+   *
+   *******************************************************************/
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfUndoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Execute 20 transactions");
+
+  /*******************************************************************
+   *
+   * Execute 20 transient transactions. Afterwards, we should still
+   * have the same 10 transactions on the undo stack:
+   *
+   *******************************************************************/
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, TRANSIENT_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfUndoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Execute 20 transient transactions");
+
+  /*******************************************************************
+   *
+   * Undo 4 transactions. Afterwards, we should have 6 transactions
+   * on the undo stack, and 4 on the redo stack:
+   *
+   *******************************************************************/
+
+  for (i = 1; i <= 4; i++) {
+    rv = mgr->UndoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to undo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 6 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 6) {
+    fail("GetNumberOfUndoItems() expected 6 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 4 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 4) {
+    fail("GetNumberOfRedoItems() expected 4 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Undo 4 transactions");
+
+  /*******************************************************************
+   *
+   * Redo 2 transactions. Afterwards, we should have 8 transactions
+   * on the undo stack, and 2 on the redo stack:
+   *
+   *******************************************************************/
+
+  for (i = 1; i <= 2; ++i) {
+    rv = mgr->RedoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to redo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 8 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 8) {
+    fail("GetNumberOfUndoItems() expected 8 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 2 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 2) {
+    fail("GetNumberOfRedoItems() expected 2 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Redo 2 transactions");
+
+  /*******************************************************************
+   *
+   * Execute a new transaction. The redo stack should get pruned!
+   *
+   *******************************************************************/
+
+  tximpl = factory->create(mgr, NONE_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("Failed to execute transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 9 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 9) {
+    fail("GetNumberOfUndoItems() expected 9 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Check if new transactions prune the redo stack");
+
+  /*******************************************************************
+   *
+   * Undo 4 transactions then clear the undo and redo stacks.
+   *
+   *******************************************************************/
+
+  for (i = 1; i <= 4; ++i) {
+    rv = mgr->UndoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to undo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 5 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 5) {
+    fail("GetNumberOfUndoItems() expected 5 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 4 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 4) {
+    fail("GetNumberOfRedoItems() expected 4 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->Clear();
+  if (NS_FAILED(rv)) {
+    fail("Clear() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on cleared undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on cleared redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Undo 4 transactions then clear the undo and redo stacks");
+
+  /*******************************************************************
+   *
+   * Execute 5 transactions.
+   *
+   *******************************************************************/
+
+  for (i = 1; i <= 5; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 5 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 5) {
+    fail("GetNumberOfUndoItems() expected 5 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Execute 5 transactions");
+
+  /*******************************************************************
+   *
+   * Test transaction DoTransaction() error:
+   *
+   *******************************************************************/
+
+  tximpl = factory->create(mgr, THROWS_DO_ERROR_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (rv != NS_ERROR_FAILURE) {
+    fail("DoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 5 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 5) {
+    fail("GetNumberOfUndoItems() expected 5 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test transaction DoTransaction() error");
+
+  /*******************************************************************
+   *
+   * Test transaction UndoTransaction() error:
+   *
+   *******************************************************************/
+
+  tximpl = factory->create(mgr, THROWS_UNDO_ERROR_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("DoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->UndoTransaction();
+  if (rv != NS_ERROR_FAILURE) {
+    fail("UndoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 6 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 6) {
+    fail("GetNumberOfUndoItems() expected 6 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test transaction UndoTransaction() error");
+
+  /*******************************************************************
+   *
+   * Test transaction RedoTransaction() error:
+   *
+   *******************************************************************/
+
+  tximpl = factory->create(mgr, THROWS_REDO_ERROR_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for RedoErrorTransaction. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+
+  if (NS_FAILED(rv)) {
+    fail("DoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  //
+  // Execute a normal transaction to be used in a later test:
+  //
+
+  tximpl = factory->create(mgr, NONE_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("DoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  //
+  // Undo the 2 transactions just executed.
+  //
+
+  for (i = 1; i <= 2; ++i) {
+    rv = mgr->UndoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to undo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+
+  //
+  // The RedoErrorTransaction should now be at the top of the redo stack!
+  //
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->RedoTransaction();
+  if (rv != NS_ERROR_FAILURE) {
+    fail("RedoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 6 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 6) {
+    fail("GetNumberOfUndoItems() expected 6 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 2 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 2) {
+    fail("GetNumberOfRedoItems() expected 2 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test transaction RedoTransaction() error");
+
+  /*******************************************************************
+   *
+   * Make sure that setting the transaction manager's max transaction
+   * count to zero, clears both the undo and redo stacks, and executes
+   * all new commands without pushing them on the undo stack!
+   *
+   *******************************************************************/
+
+  rv = mgr->SetMaxTransactionCount(0);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(0) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+
+    rv = mgr->GetNumberOfUndoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+           rv);
+      return rv;
+    }
+
+    if (numitems) {
+      fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+           numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+
+    rv = mgr->GetNumberOfRedoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+           rv);
+      return rv;
+    }
+
+    if (numitems) {
+      fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+           numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  passed("Test max transaction count of zero");
+
+  /*******************************************************************
+   *
+   * Make sure that setting the transaction manager's max transaction
+   * count to something greater than the number of transactions on
+   * both the undo and redo stacks causes no pruning of the stacks:
+   *
+   *******************************************************************/
+
+  rv = mgr->SetMaxTransactionCount(-1);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(-1) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  // Push 20 transactions on the undo stack:
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+
+    rv = mgr->GetNumberOfUndoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfUndoItems() on undo stack with %d items failed. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    if (numitems != i) {
+      fail("GetNumberOfUndoItems() expected %d got %d. (%d)\n",
+           i, numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+
+    rv = mgr->GetNumberOfRedoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+           rv);
+      return rv;
+    }
+
+    if (numitems) {
+      fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+           numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  for (i = 1; i <= 10; i++) {
+    rv = mgr->UndoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to undo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfUndoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfRedoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->SetMaxTransactionCount(25);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(25) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfUndoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfRedoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test SetMaxTransactionCount() greater than num stack items");
+
+  /*******************************************************************
+   *
+   * Test undo stack pruning by setting the transaction
+   * manager's max transaction count to a number lower than the
+   * number of transactions on both the undo and redo stacks:
+   *
+   *******************************************************************/
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->SetMaxTransactionCount(15);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(15) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 5 items failed. (%d)\n",
+           rv);
+    return rv;
+  }
+
+  if (numitems != 5) {
+    fail("GetNumberOfUndoItems() expected 5 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfRedoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test SetMaxTransactionCount() pruning undo stack");
+
+  /*******************************************************************
+   *
+   * Test redo stack pruning by setting the transaction
+   * manager's max transaction count to a number lower than the
+   * number of transactions on both the undo and redo stacks:
+   *
+   *******************************************************************/
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->SetMaxTransactionCount(5);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(5) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u2) {
+    fail("Unexpected item at top of undo stack. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 0) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 5 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 5) {
+    fail("GetNumberOfRedoItems() expected 5 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test SetMaxTransactionCount() pruning redo stack");
+
+  /*******************************************************************
+   *
+   * Release the transaction manager. Any transactions on the undo
+   * and redo stack should automatically be released:
+   *
+   *******************************************************************/
+
+  rv = mgr->SetMaxTransactionCount(-1);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(-1) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  // Push 20 transactions on the undo stack:
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+
+    rv = mgr->GetNumberOfUndoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfUndoItems() on undo stack with %d items failed. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    if (numitems != i) {
+      fail("GetNumberOfUndoItems() expected %d got %d. (%d)\n",
+           i, numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+
+    rv = mgr->GetNumberOfRedoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+           rv);
+      return rv;
+    }
+
+    if (numitems) {
+      fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+           numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  for (i = 1; i <= 10; i++) {
+    rv = mgr->UndoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to undo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfUndoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfRedoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->Clear();
+  if (NS_FAILED(rv)) {
+    fail("Clear() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Release the transaction manager");
+
+  /*******************************************************************
+   *
+   * Make sure number of transactions created matches number of
+   * transactions destroyed!
+   *
+   *******************************************************************/
+
+  /* Disabled because the current cycle collector doesn't delete
+     cycle collectable objects synchronously.
+  if (sConstructorCount != sDestructorCount) {
+    fail("Transaction constructor count (%d) != destructor count (%d).\n",
+         sConstructorCount, sDestructorCount);
+    return NS_ERROR_FAILURE;
+  }*/
+
+  passed("Number of transactions created and destroyed match");
+  passed("%d transactions processed during quick test", sConstructorCount);
+
+  return NS_OK;
+}
+
+nsresult
+simple_test()
+{
+  /*******************************************************************
+   *
+   * Initialize globals for test.
+   *
+   *******************************************************************/
+  reset_globals();
+  sDestructorOrderArr = sSimpleTestDestructorOrderArr;
+  sDoOrderArr         = sSimpleTestDoOrderArr;
+  sUndoOrderArr       = sSimpleTestUndoOrderArr;
+  sRedoOrderArr       = sSimpleTestRedoOrderArr;
+
+  /*******************************************************************
+   *
+   * Run the quick test.
+   *
+   *******************************************************************/
+
+  printf("\n-----------------------------------------------------\n");
+  printf("- Begin Simple Transaction Test:\n");
+  printf("-----------------------------------------------------\n");
+
+  SimpleTransactionFactory factory;
+
+  return quick_test(&factory);
+}
+
+nsresult
+aggregation_test()
+{
+  /*******************************************************************
+   *
+   * Initialize globals for test.
+   *
+   *******************************************************************/
+
+  reset_globals();
+  sDestructorOrderArr = sAggregateTestDestructorOrderArr;
+  sDoOrderArr         = sAggregateTestDoOrderArr;
+  sUndoOrderArr       = sAggregateTestUndoOrderArr;
+  sRedoOrderArr       = sAggregateTestRedoOrderArr;
+
+  /*******************************************************************
+   *
+   * Run the quick test.
+   *
+   *******************************************************************/
+
+  printf("\n-----------------------------------------------------\n");
+  printf("- Begin Aggregate Transaction Test:\n");
+  printf("-----------------------------------------------------\n");
+
+  AggregateTransactionFactory factory(3, 2);
+
+  return quick_test(&factory);
+}
+
+/**
+ * Test behaviors in batch mode.
+ **/
+nsresult
+quick_batch_test(TestTransactionFactory *factory)
+{
+  /*******************************************************************
+   *
+   * Create a transaction manager implementation:
+   *
+   *******************************************************************/
+
+  nsresult rv;
+  nsCOMPtr<nsITransactionManager> mgr =
+    do_CreateInstance(NS_TRANSACTIONMANAGER_CONTRACTID, &rv);
+  if (NS_FAILED(rv) || !mgr) {
+    fail("Failed to create Transaction Manager instance.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  passed("Create transaction manager instance");
+
+  int32_t numitems;
+
+  /*******************************************************************
+   *
+   * Make sure an unbalanced call to EndBatch(false) with empty undo stack
+   * throws an error!
+   *
+   *******************************************************************/
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->EndBatch(false);
+  if (rv != NS_ERROR_FAILURE) {
+    fail("EndBatch(false) returned unexpected status. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test unbalanced EndBatch(false) with empty undo stack");
+
+  /*******************************************************************
+   *
+   * Make sure that an empty batch is not added to the undo stack
+   * when it is closed.
+   *
+   *******************************************************************/
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test empty batch");
+
+  int32_t i;
+  TestTransaction *tximpl;
+  nsITransaction *tx;
+
+  /*******************************************************************
+   *
+   * Execute 20 transactions. Afterwards, we should have 1
+   * transaction on the undo stack:
+   *
+   *******************************************************************/
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 0) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Execute 20 batched transactions");
+
+  nsITransaction *u1, *u2;
+  nsITransaction *r1, *r2;
+
+  /*******************************************************************
+   *
+   * Execute 20 transient transactions. Afterwards, we should still
+   * have the same transaction on the undo stack:
+   *
+   *******************************************************************/
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, TRANSIENT_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+  }
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Execute 20 batched transient transactions");
+
+  /*******************************************************************
+   *
+   * Test nested batching. Afterwards, we should have 2 transactions
+   * on the undo stack:
+   *
+   *******************************************************************/
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  tximpl = factory->create(mgr, NONE_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx = 0;
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("Failed to execute transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  tximpl = factory->create(mgr, NONE_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx = 0;
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("Failed to execute transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  tximpl = factory->create(mgr, NONE_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx = 0;
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("Failed to execute transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 2 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 2) {
+    fail("GetNumberOfUndoItems() expected 2 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test nested batched transactions");
+
+  /*******************************************************************
+   *
+   * Undo 2 batch transactions. Afterwards, we should have 0
+   * transactions on the undo stack and 2 on the redo stack.
+   *
+   *******************************************************************/
+
+  for (i = 1; i <= 2; ++i) {
+    rv = mgr->UndoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to undo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 2 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 2) {
+    fail("GetNumberOfRedoItems() expected 2 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Undo 2 batch transactions");
+
+  /*******************************************************************
+   *
+   * Redo 2 batch transactions. Afterwards, we should have 2
+   * transactions on the undo stack and 0 on the redo stack.
+   *
+   *******************************************************************/
+
+  for (i = 1; i <= 2; ++i) {
+    rv = mgr->RedoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to undo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 2 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 2) {
+    fail("GetNumberOfUndoItems() expected 2 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Redo 2 batch transactions");
+
+  /*******************************************************************
+   *
+   * Call undo. Afterwards, we should have 1 transaction
+   * on the undo stack, and 1 on the redo stack:
+   *
+   *******************************************************************/
+
+  rv = mgr->UndoTransaction();
+  if (NS_FAILED(rv)) {
+    fail("Failed to undo transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfRedoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Undo a batched transaction that was redone");
+
+  /*******************************************************************
+   *
+   * Make sure an unbalanced call to EndBatch(false) throws an error and
+   * doesn't affect the undo and redo stacks!
+   *
+   *******************************************************************/
+
+  rv = mgr->EndBatch(false);
+  if (rv != NS_ERROR_FAILURE) {
+    fail("EndBatch(false) returned unexpected status. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfRedoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test effect of unbalanced EndBatch(false) on undo and redo stacks");
+
+  /*******************************************************************
+   *
+   * Make sure that an empty batch is not added to the undo stack
+   * when it is closed, and that it does not affect the undo and redo
+   * stacks.
+   *
+   *******************************************************************/
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfRedoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfRedoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test effect of empty batch on undo and redo stacks");
+
+  /*******************************************************************
+   *
+   * Execute a new transaction. The redo stack should get pruned!
+   *
+   *******************************************************************/
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfRedoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 2 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 2) {
+    fail("GetNumberOfUndoItems() expected 2 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Check if new batched transactions prune the redo stack");
+
+  /*******************************************************************
+   *
+   * Call undo.
+   *
+   *******************************************************************/
+
+  // Move a transaction over to the redo stack, so that we have one
+  // transaction on the undo stack, and one on the redo stack!
+
+  rv = mgr->UndoTransaction();
+  if (NS_FAILED(rv)) {
+    fail("Failed to undo transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfRedoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Call undo");
+
+  /*******************************************************************
+   *
+   * Test transaction DoTransaction() error:
+   *
+   *******************************************************************/
+
+  tximpl = factory->create(mgr, THROWS_DO_ERROR_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx     = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (rv != NS_ERROR_FAILURE) {
+    fail("DoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfUndoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 1 item failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 1) {
+    fail("GetNumberOfRedoItems() expected 1 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test transaction DoTransaction() error");
+
+  /*******************************************************************
+   *
+   * Test transaction UndoTransaction() error:
+   *
+   *******************************************************************/
+
+  tximpl = factory->create(mgr, THROWS_UNDO_ERROR_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx     = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("DoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->UndoTransaction();
+  if (rv != NS_ERROR_FAILURE) {
+    fail("UndoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 2 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 2) {
+    fail("GetNumberOfUndoItems() expected 2 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test transaction UndoTransaction() error");
+
+  /*******************************************************************
+   *
+   * Test transaction RedoTransaction() error:
+   *
+   *******************************************************************/
+
+  tximpl = factory->create(mgr, THROWS_REDO_ERROR_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx     = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for RedoErrorTransaction. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  rv = mgr->BeginBatch(nullptr);
+  if (NS_FAILED(rv)) {
+    fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("DoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  rv = mgr->EndBatch(false);
+  if (NS_FAILED(rv)) {
+    fail("EndBatch(false) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  //
+  // Execute a normal transaction to be used in a later test:
+  //
+
+  tximpl = factory->create(mgr, NONE_FLAG);
+
+  if (!tximpl) {
+    fail("Failed to allocate transaction.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  tx     = 0;
+
+  rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+  if (NS_FAILED(rv)) {
+    fail("QueryInterface() failed for transaction. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->DoTransaction(tx);
+  if (NS_FAILED(rv)) {
+    fail("DoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  tx->Release();
+
+  //
+  // Undo the 2 transactions just executed.
+  //
+
+  for (i = 1; i <= 2; ++i) {
+    rv = mgr->UndoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to undo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+
+  //
+  // The RedoErrorTransaction should now be at the top of the redo stack!
+  //
+
+  u1 = u2 = r1 = r2 = 0;
+
+  rv = mgr->PeekUndoStack(&u1);
+
+  TEST_TXMGR_IF_RELEASE(u1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekRedoStack(&r1);
+
+  TEST_TXMGR_IF_RELEASE(r1); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Initial PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->RedoTransaction();
+  if (rv != NS_ERROR_FAILURE) {
+    fail("RedoTransaction() returned unexpected error. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->PeekUndoStack(&u2);
+
+  TEST_TXMGR_IF_RELEASE(u2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekUndoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (u1 != u2) {
+    fail("Top of undo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->PeekRedoStack(&r2);
+
+  TEST_TXMGR_IF_RELEASE(r2); // Don't hold onto any references!
+
+  if (NS_FAILED(rv)) {
+    fail("Second PeekRedoStack() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  if (r1 != r2) {
+    fail("Top of redo stack changed. (%d)\n", rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on undo stack with 2 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 2) {
+    fail("GetNumberOfUndoItems() expected 2 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 2 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 2) {
+    fail("GetNumberOfRedoItems() expected 2 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("Test transaction RedoTransaction() error");
+
+  /*******************************************************************
+   *
+   * Make sure that setting the transaction manager's max transaction
+   * count to zero, clears both the undo and redo stacks, and executes
+   * all new commands without pushing them on the undo stack!
+   *
+   *******************************************************************/
+
+  rv = mgr->SetMaxTransactionCount(0);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(0) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems) {
+    fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->BeginBatch(nullptr);
+    if (NS_FAILED(rv)) {
+      fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+
+    rv = mgr->EndBatch(false);
+    if (NS_FAILED(rv)) {
+      fail("EndBatch(false) failed. (%d)\n", rv);
+      return rv;
+    }
+
+    rv = mgr->GetNumberOfUndoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfUndoItems() on empty undo stack failed. (%d)\n",
+           rv);
+      return rv;
+    }
+
+    if (numitems) {
+      fail("GetNumberOfUndoItems() expected 0 got %d. (%d)\n",
+           numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+
+    rv = mgr->GetNumberOfRedoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+           rv);
+      return rv;
+    }
+
+    if (numitems) {
+      fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+           numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  passed("Test max transaction count of zero");
+
+  /*******************************************************************
+   *
+   * Release the transaction manager. Any transactions on the undo
+   * and redo stack should automatically be released:
+   *
+   *******************************************************************/
+
+  rv = mgr->SetMaxTransactionCount(-1);
+  if (NS_FAILED(rv)) {
+    fail("SetMaxTransactionCount(0) failed. (%d)\n", rv);
+    return rv;
+  }
+
+  // Push 20 transactions on the undo stack:
+
+  for (i = 1; i <= 20; i++) {
+    tximpl = factory->create(mgr, NONE_FLAG);
+
+    if (!tximpl) {
+      fail("Failed to allocate transaction %d.\n", i);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    tx = 0;
+    rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+    if (NS_FAILED(rv)) {
+      fail("QueryInterface() failed for transaction %d. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    rv = mgr->BeginBatch(nullptr);
+    if (NS_FAILED(rv)) {
+      fail("BeginBatch(nullptr) failed. (%d)\n", rv);
+      return rv;
+    }
+
+    rv = mgr->DoTransaction(tx);
+    if (NS_FAILED(rv)) {
+      fail("Failed to execute transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+
+    tx->Release();
+
+    rv = mgr->EndBatch(false);
+    if (NS_FAILED(rv)) {
+      fail("EndBatch(false) failed. (%d)\n", rv);
+      return rv;
+    }
+
+    rv = mgr->GetNumberOfUndoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfUndoItems() on undo stack with %d items failed. (%d)\n",
+           i, rv);
+      return rv;
+    }
+
+    if (numitems != i) {
+      fail("GetNumberOfUndoItems() expected %d got %d. (%d)\n",
+           i, numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+
+    rv = mgr->GetNumberOfRedoItems(&numitems);
+    if (NS_FAILED(rv)) {
+      fail("GetNumberOfRedoItems() on empty redo stack failed. (%d)\n",
+           rv);
+      return rv;
+    }
+
+    if (numitems) {
+      fail("GetNumberOfRedoItems() expected 0 got %d. (%d)\n",
+           numitems, rv);
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  for (i = 1; i <= 10; i++) {
+    rv = mgr->UndoTransaction();
+    if (NS_FAILED(rv)) {
+      fail("Failed to undo transaction %d. (%d)\n", i, rv);
+      return rv;
+    }
+  }
+
+  rv = mgr->GetNumberOfUndoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfUndoItems() on empty undo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfUndoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->GetNumberOfRedoItems(&numitems);
+  if (NS_FAILED(rv)) {
+    fail("GetNumberOfRedoItems() on redo stack with 10 items failed. (%d)\n",
+         rv);
+    return rv;
+  }
+
+  if (numitems != 10) {
+    fail("GetNumberOfRedoItems() expected 10 got %d. (%d)\n",
+         numitems, rv);
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = mgr->Clear();
+  if (NS_FAILED(rv)) {
+    fail("Clear() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  passed("Release the transaction manager");
+
+  /*******************************************************************
+   *
+   * Make sure number of transactions created matches number of
+   * transactions destroyed!
+   *
+   *******************************************************************/
+
+  /* Disabled because the current cycle collector doesn't delete
+     cycle collectable objects synchronously.
+  if (sConstructorCount != sDestructorCount) {
+    fail("Transaction constructor count (%d) != destructor count (%d).\n",
+         sConstructorCount, sDestructorCount);
+    return NS_ERROR_FAILURE;
+  }*/
+
+  passed("Number of transactions created and destroyed match");
+  passed("%d transactions processed during quick batch test",
+         sConstructorCount);
+
+  return NS_OK;
+}
+
+nsresult
+simple_batch_test()
+{
+  /*******************************************************************
+   *
+   * Initialize globals for test.
+   *
+   *******************************************************************/
+  reset_globals();
+  sDestructorOrderArr = sSimpleBatchTestDestructorOrderArr;
+  sDoOrderArr         = sSimpleBatchTestDoOrderArr;
+  sUndoOrderArr       = sSimpleBatchTestUndoOrderArr;
+  sRedoOrderArr       = sSimpleBatchTestRedoOrderArr;
+
+  /*******************************************************************
+   *
+   * Run the quick batch test.
+   *
+   *******************************************************************/
+
+  printf("\n-----------------------------------------------------\n");
+  printf("- Begin Batch Transaction Test:\n");
+  printf("-----------------------------------------------------\n");
+
+  SimpleTransactionFactory factory;
+
+  return quick_batch_test(&factory);
+}
+
+nsresult
+aggregation_batch_test()
+{
+  /*******************************************************************
+   *
+   * Initialize globals for test.
+   *
+   *******************************************************************/
+
+  reset_globals();
+  sDestructorOrderArr = sAggregateBatchTestDestructorOrderArr;
+  sDoOrderArr         = sAggregateBatchTestDoOrderArr;
+  sUndoOrderArr       = sAggregateBatchTestUndoOrderArr;
+  sRedoOrderArr       = sAggregateBatchTestRedoOrderArr;
+
+  /*******************************************************************
+   *
+   * Run the quick batch test.
+   *
+   *******************************************************************/
+
+  printf("\n-----------------------------------------------------\n");
+  printf("- Begin Batch Aggregate Transaction Test:\n");
+  printf("-----------------------------------------------------\n");
+
+  AggregateTransactionFactory factory(3, 2, BATCH_FLAG);
+
+  return quick_batch_test(&factory);
+}
+
+/**
+ * Create 'iterations * (iterations + 1) / 2' transactions;
+ * do/undo/redo/undo them.
+ **/
+nsresult
+stress_test(TestTransactionFactory *factory, int32_t iterations)
+{
+  printf("Stress test of %i iterations (may take a while) ... ", iterations);
+  fflush(stdout);
+
+  /*******************************************************************
+   *
+   * Create a transaction manager:
+   *
+   *******************************************************************/
+
+  nsresult rv;
+  nsCOMPtr<nsITransactionManager> mgr =
+    do_CreateInstance(NS_TRANSACTIONMANAGER_CONTRACTID, &rv);
+  if (NS_FAILED(rv) || !mgr) {
+    fail("Failed to create Transaction Manager instance.\n");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  int32_t i, j;
+  nsITransaction *tx;
+
+  for (i = 1; i <= iterations; i++) {
+    /*******************************************************************
+     *
+     * Create and execute a bunch of transactions:
+     *
+     *******************************************************************/
+
+    for (j = 1; j <= i; j++) {
+      TestTransaction *tximpl = factory->create(mgr, NONE_FLAG);
+
+      if (!tximpl) {
+        fail("Failed to allocate transaction %d-%d.\n", i, j);
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+
+      tx = 0;
+      rv = tximpl->QueryInterface(NS_GET_IID(nsITransaction), (void **)&tx);
+      if (NS_FAILED(rv)) {
+        fail("QueryInterface() failed for transaction %d-%d. (%d)\n",
+             i, j, rv);
+        return rv;
+      }
+
+      rv = mgr->DoTransaction(tx);
+      if (NS_FAILED(rv)) {
+        fail("Failed to execute transaction %d-%d. (%d)\n",
+             i, j, rv);
+        return rv;
+      }
+
+      tx->Release();
+    }
+
+    /*******************************************************************
+     *
+     * Undo all the transactions:
+     *
+     *******************************************************************/
+
+    for (j = 1; j <= i; j++) {
+      rv = mgr->UndoTransaction();
+      if (NS_FAILED(rv)) {
+        fail("Failed to undo transaction %d-%d. (%d)\n", i, j, rv);
+        return rv;
+      }
+    }
+
+    /*******************************************************************
+     *
+     * Redo all the transactions:
+     *
+     *******************************************************************/
+
+    for (j = 1; j <= i; j++) {
+      rv = mgr->RedoTransaction();
+      if (NS_FAILED(rv)) {
+        fail("Failed to redo transaction %d-%d. (%d)\n", i, j, rv);
+        return rv;
+      }
+    }
+
+    /*******************************************************************
+     *
+     * Undo all the transactions again so that they all end up on
+     * the redo stack for pruning the next time we execute a new
+     * transaction
+     *
+     *******************************************************************/
+
+    for (j = 1; j <= i; j++) {
+      rv = mgr->UndoTransaction();
+      if (NS_FAILED(rv)) {
+        fail("Failed to undo transaction %d-%d. (%d)\n", i, j, rv);
+        return rv;
+      }
+    }
+
+    // Trivial feedback not to let the user think the test is stuck.
+    if (MOZ_UNLIKELY(j % 100 == 0)) {
+      printf("%i ", j);
+    }
+  } // for, iterations.
+
+  printf("passed\n");
+
+  rv = mgr->Clear();
+  if (NS_FAILED(rv)) {
+    fail("Clear() failed. (%d)\n", rv);
+    return rv;
+  }
+
+  /* Disabled because the current cycle collector doesn't delete
+     cycle collectable objects synchronously.
+  if (sConstructorCount != sDestructorCount) {
+    fail("Transaction constructor count (%d) != destructor count (%d).\n",
+         sConstructorCount, sDestructorCount);
+    return NS_ERROR_FAILURE;
+  }*/
+
+  passed("%d transactions processed during stress test", sConstructorCount);
+
+  return NS_OK;
+}
+
+nsresult
+simple_stress_test()
+{
+  /*******************************************************************
+   *
+   * Initialize globals for test.
+   *
+   *******************************************************************/
+
+  reset_globals();
+
+  /*******************************************************************
+   *
+   * Do the stress test:
+   *
+   *******************************************************************/
+
+  printf("\n-----------------------------------------------------\n");
+  printf("- Simple Transaction Stress Test:\n");
+  printf("-----------------------------------------------------\n");
+
+  SimpleTransactionFactory factory;
+
+  int32_t iterations =
+#ifdef DEBUG
+  10
+#else
+  //
+  // 1500 iterations sends 1,125,750 transactions through the system!!
+  //
+  1500
+#endif
+  ;
+  return stress_test(&factory, iterations);
+}
+
+nsresult
+aggregation_stress_test()
+{
+  /*******************************************************************
+   *
+   * Initialize globals for test.
+   *
+   *******************************************************************/
+
+  reset_globals();
+
+  /*******************************************************************
+   *
+   * Do the stress test:
+   *
+   *******************************************************************/
+
+  printf("\n-----------------------------------------------------\n");
+  printf("- Aggregate Transaction Stress Test:\n");
+  printf("-----------------------------------------------------\n");
+
+  AggregateTransactionFactory factory(3, 4);
+
+  int32_t iterations =
+#ifdef DEBUG
+  10
+#else
+  //
+  // 500 iterations sends 2,630,250 transactions through the system!!
+  //
+  500
+#endif
+  ;
+  return stress_test(&factory, iterations);
+}
+
+nsresult
+aggregation_batch_stress_test()
+{
+  /*******************************************************************
+   *
+   * Initialize globals for test.
+   *
+   *******************************************************************/
+
+  reset_globals();
+
+  /*******************************************************************
+   *
+   * Do the stress test:
+   *
+   *******************************************************************/
+
+  printf("\n-----------------------------------------------------\n");
+  printf("- Aggregate Batch Transaction Stress Test:\n");
+  printf("-----------------------------------------------------\n");
+
+  AggregateTransactionFactory factory(3, 4, BATCH_FLAG);
+
+  int32_t iterations =
+#ifdef DEBUG
+  10
+#else
+#if defined(MOZ_ASAN) || defined(MOZ_WIDGET_ANDROID)
+  // See Bug 929985: 500 is too many for ASAN and Android, 100 is safe.
+  100
+#else
+  //
+  // 500 iterations sends 2,630,250 transactions through the system!!
+  //
+  500
+#endif
+#endif
+  ;
+  return stress_test(&factory, iterations);
+}
+
+int
+main (int argc, char *argv[])
+{
+  ScopedXPCOM xpcom("nsITransactionManager");
+  if (xpcom.failed()) {
+    return 1;
+  }
+
+  //
+  // quick_test() part:
+  //
+
+  nsresult rv = simple_test();
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  rv = aggregation_test();
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  //
+  // quick_batch_test() part:
+  //
+
+  rv = simple_batch_test();
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  rv = aggregation_batch_test();
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  //
+  // stress_test() part:
+  //
+
+  rv = simple_stress_test();
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  rv = aggregation_stress_test();
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  rv = aggregation_batch_stress_test();
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  return 0;
+}
diff --git a/editor/txmgr/tests/crashtests/407072-1.html b/editor/txmgr/tests/crashtests/407072-1.html
new file mode 100644
index 000000000..e3aa3c216
--- /dev/null
+++ b/editor/txmgr/tests/crashtests/407072-1.html
@@ -0,0 +1,22 @@
+<html>
+<head>
+<script>
+
+function boom()
+{
+  var br = document.getElementById("br");
+  br.contentEditable = "true";
+  br.focus();
+
+  try { document.execCommand("justifyfull", false, null);  } catch(e) { }
+  try { document.execCommand("justifyfull", false, null);  } catch(e) { }
+        document.execCommand("underline",   false, null);
+        document.execCommand("insertimage", false, "foo");
+  try { document.execCommand("outdent",     false, null);  } catch(e) { }
+}
+
+</script>
+</head>
+
+<body onload="boom();"><br id="br"></body>
+</html>
diff --git a/editor/txmgr/tests/crashtests/449006-1.html b/editor/txmgr/tests/crashtests/449006-1.html
new file mode 100644
index 000000000..65e6ed981
--- /dev/null
+++ b/editor/txmgr/tests/crashtests/449006-1.html
@@ -0,0 +1,28 @@
+<html>
+<head>
+<script type="text/javascript">
+
+function boom()
+{
+  document.getElementById("d").focus();
+  document.execCommand("inserthtml", false, "AB");
+  document.execCommand("delete", false, null);
+  document.execCommand("undo", false, null);
+
+  document.addEventListener("DOMCharacterDataModified", f, false);
+  document.execCommand("redo", false, null);
+  document.removeEventListener("DOMCharacterDataModified", f, false);
+
+  function f()
+  {
+    document.removeEventListener("DOMCharacterDataModified", f, false);
+    document.execCommand("formatBlock", false, "<h3>");
+  }
+}
+
+</script>
+</head>
+
+<body onload="boom();"><div id="d" contenteditable="true"></div></body>
+
+</html>
diff --git a/editor/txmgr/tests/crashtests/crashtests.list b/editor/txmgr/tests/crashtests/crashtests.list
new file mode 100644
index 000000000..d39187592
--- /dev/null
+++ b/editor/txmgr/tests/crashtests/crashtests.list
@@ -0,0 +1,2 @@
+needs-focus load 407072-1.html
+load 449006-1.html
diff --git a/editor/txmgr/tests/moz.build b/editor/txmgr/tests/moz.build
new file mode 100644
index 000000000..d04d4f15a
--- /dev/null
+++ b/editor/txmgr/tests/moz.build
@@ -0,0 +1,9 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+GeckoCppUnitTests([
+    'TestTXMgr',
+])