Issue #1258 - Part 1: Import mailnews, ldap, and mork from comm-esr52.9.1

1 files changed, 8066 insertions, 0 deletions

diff --git a/mailnews/base/src/nsMsgDBView.cpp b/mailnews/base/src/nsMsgDBView.cpp
new file mode 100644
index 000000000..f7856dd4d
--- /dev/null
+++ b/mailnews/base/src/nsMsgDBView.cpp
@@ -0,0 +1,8066 @@
+/* -*- 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 "msgCore.h"
+#include "prmem.h"
+#include "nsArrayUtils.h"
+#include "nsIMsgCustomColumnHandler.h"
+#include "nsMsgDBView.h"
+#include "nsISupports.h"
+#include "nsIMsgFolder.h"
+#include "nsIDBFolderInfo.h"
+#include "nsIMsgDatabase.h"
+#include "nsIMsgFolder.h"
+#include "MailNewsTypes2.h"
+#include "nsMsgUtils.h"
+#include "nsQuickSort.h"
+#include "nsIMsgImapMailFolder.h"
+#include "nsImapCore.h"
+#include "nsMsgFolderFlags.h"
+#include "nsIMsgLocalMailFolder.h"
+#include "nsIDOMElement.h"
+#include "nsDateTimeFormatCID.h"
+#include "nsMsgMimeCID.h"
+#include "nsIPrefService.h"
+#include "nsIPrefBranch.h"
+#include "nsIPrefLocalizedString.h"
+#include "nsIMsgSearchSession.h"
+#include "nsIMsgCopyService.h"
+#include "nsMsgBaseCID.h"
+#include "nsISpamSettings.h"
+#include "nsIMsgAccountManager.h"
+#include "nsITreeColumns.h"
+#include "nsTextFormatter.h"
+#include "nsIMutableArray.h"
+#include "nsIMimeConverter.h"
+#include "nsMsgMessageFlags.h"
+#include "nsIPrompt.h"
+#include "nsIWindowWatcher.h"
+#include "nsMsgDBCID.h"
+#include "nsIMsgFolderNotificationService.h"
+#include "nsServiceManagerUtils.h"
+#include "nsComponentManagerUtils.h"
+#include "nsMemory.h"
+#include "nsAlgorithm.h"
+#include "nsIAbManager.h"
+#include "nsIAbDirectory.h"
+#include "nsIAbCard.h"
+#include "mozilla/Services.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/mailnews/MimeHeaderParser.h"
+#include "nsTArray.h"
+#include <algorithm>
+
+using namespace mozilla::mailnews;
+nsrefcnt nsMsgDBView::gInstanceCount  = 0;
+
+nsIAtom * nsMsgDBView::kJunkMsgAtom = nullptr;
+nsIAtom * nsMsgDBView::kNotJunkMsgAtom = nullptr;
+
+char16_t * nsMsgDBView::kHighestPriorityString = nullptr;
+char16_t * nsMsgDBView::kHighPriorityString = nullptr;
+char16_t * nsMsgDBView::kLowestPriorityString = nullptr;
+char16_t * nsMsgDBView::kLowPriorityString = nullptr;
+char16_t * nsMsgDBView::kNormalPriorityString = nullptr;
+char16_t * nsMsgDBView::kReadString = nullptr;
+char16_t * nsMsgDBView::kRepliedString = nullptr;
+char16_t * nsMsgDBView::kForwardedString = nullptr;
+char16_t * nsMsgDBView::kNewString = nullptr;
+
+nsDateFormatSelector  nsMsgDBView::m_dateFormatDefault = kDateFormatShort;
+nsDateFormatSelector  nsMsgDBView::m_dateFormatThisWeek = kDateFormatShort;
+nsDateFormatSelector  nsMsgDBView::m_dateFormatToday = kDateFormatNone;
+
+static const uint32_t kMaxNumSortColumns = 2;
+
+static void GetCachedName(const nsCString& unparsedString,
+                          int32_t displayVersion, nsACString& cachedName);
+
+static void UpdateCachedName(nsIMsgDBHdr *aHdr, const char *header_field,
+                             const nsAString& newName);
+
+// this is passed into NS_QuickSort as custom data.
+class viewSortInfo
+{
+public:
+  nsMsgDBView *view;
+  nsIMsgDatabase *db;
+  bool isSecondarySort;
+  bool ascendingSort;
+};
+
+
+NS_IMPL_ADDREF(nsMsgDBView)
+NS_IMPL_RELEASE(nsMsgDBView)
+
+NS_INTERFACE_MAP_BEGIN(nsMsgDBView)
+   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIMsgDBView)
+   NS_INTERFACE_MAP_ENTRY(nsIMsgDBView)
+   NS_INTERFACE_MAP_ENTRY(nsIDBChangeListener)
+   NS_INTERFACE_MAP_ENTRY(nsITreeView)
+   NS_INTERFACE_MAP_ENTRY(nsIJunkMailClassificationListener)
+NS_INTERFACE_MAP_END
+
+nsMsgDBView::nsMsgDBView()
+{
+  /* member initializers and constructor code */
+  m_sortValid = false;
+  m_checkedCustomColumns = false;
+  m_sortOrder = nsMsgViewSortOrder::none;
+  m_viewFlags = nsMsgViewFlagsType::kNone;
+  m_secondarySort = nsMsgViewSortType::byId;
+  m_secondarySortOrder = nsMsgViewSortOrder::ascending;
+  m_cachedMsgKey = nsMsgKey_None;
+  m_currentlyDisplayedMsgKey = nsMsgKey_None;
+  m_currentlyDisplayedViewIndex = nsMsgViewIndex_None;
+  mNumSelectedRows = 0;
+  mSuppressMsgDisplay = false;
+  mSuppressCommandUpdating = false;
+  mSuppressChangeNotification = false;
+  mSummarizeFailed = false;
+  mSelectionSummarized = false;
+  mGoForwardEnabled = false;
+  mGoBackEnabled = false;
+
+  mIsNews = false;
+  mIsRss = false;
+  mIsXFVirtual = false;
+  mDeleteModel = nsMsgImapDeleteModels::MoveToTrash;
+  m_deletingRows = false;
+  mNumMessagesRemainingInBatch = 0;
+  mShowSizeInLines = false;
+  mSortThreadsByRoot = false;
+
+  /* mCommandsNeedDisablingBecauseOfSelection - A boolean that tell us if we needed to disable commands because of what's selected.
+    If we're offline w/o a downloaded msg selected, or a dummy message was selected.
+  */
+
+  mCommandsNeedDisablingBecauseOfSelection = false;
+  mRemovingRow = false;
+  m_saveRestoreSelectionDepth = 0;
+  mRecentlyDeletedArrayIndex = 0;
+  // initialize any static atoms or unicode strings
+  if (gInstanceCount == 0)
+  {
+    InitializeAtomsAndLiterals();
+    InitDisplayFormats();
+  }
+
+  InitLabelStrings();
+  gInstanceCount++;
+}
+
+void nsMsgDBView::InitializeAtomsAndLiterals()
+{
+  kJunkMsgAtom = MsgNewAtom("junk").take();
+  kNotJunkMsgAtom = MsgNewAtom("notjunk").take();
+
+  // priority strings
+  kHighestPriorityString = GetString(u"priorityHighest");
+  kHighPriorityString = GetString(u"priorityHigh");
+  kLowestPriorityString = GetString(u"priorityLowest");
+  kLowPriorityString = GetString(u"priorityLow");
+  kNormalPriorityString = GetString(u"priorityNormal");
+
+  kReadString = GetString(u"read");
+  kRepliedString = GetString(u"replied");
+  kForwardedString = GetString(u"forwarded");
+  kNewString = GetString(u"new");
+}
+
+nsMsgDBView::~nsMsgDBView()
+{
+  if (m_db)
+    m_db->RemoveListener(this);
+
+  gInstanceCount--;
+  if (gInstanceCount <= 0)
+  {
+    NS_IF_RELEASE(kJunkMsgAtom);
+    NS_IF_RELEASE(kNotJunkMsgAtom);
+
+    NS_Free(kHighestPriorityString);
+    NS_Free(kHighPriorityString);
+    NS_Free(kLowestPriorityString);
+    NS_Free(kLowPriorityString);
+    NS_Free(kNormalPriorityString);
+
+    NS_Free(kReadString);
+    NS_Free(kRepliedString);
+    NS_Free(kForwardedString);
+    NS_Free(kNewString);
+  }
+}
+
+nsresult nsMsgDBView::InitLabelStrings()
+{
+  nsresult rv = NS_OK;
+  nsCString prefString;
+
+  for(int32_t i = 0; i < PREF_LABELS_MAX; i++)
+  {
+    prefString.Assign(PREF_LABELS_DESCRIPTION);
+    prefString.AppendInt(i + 1);
+    rv = GetPrefLocalizedString(prefString.get(), mLabelPrefDescriptions[i]);
+  }
+  return rv;
+}
+
+// helper function used to fetch strings from the messenger string bundle
+char16_t * nsMsgDBView::GetString(const char16_t *aStringName)
+{
+  nsresult    res = NS_ERROR_UNEXPECTED;
+  char16_t   *ptrv = nullptr;
+
+  if (!mMessengerStringBundle)
+  {
+    static const char propertyURL[] = MESSENGER_STRING_URL;
+    nsCOMPtr<nsIStringBundleService> sBundleService =
+      mozilla::services::GetStringBundleService();
+    if (sBundleService)
+      res = sBundleService->CreateBundle(propertyURL, getter_AddRefs(mMessengerStringBundle));
+  }
+
+  if (mMessengerStringBundle)
+    res = mMessengerStringBundle->GetStringFromName(aStringName, &ptrv);
+
+  if ( NS_SUCCEEDED(res) && (ptrv) )
+    return ptrv;
+  else
+    return NS_strdup(aStringName);
+}
+
+// helper function used to fetch localized strings from the prefs
+nsresult nsMsgDBView::GetPrefLocalizedString(const char *aPrefName, nsString& aResult)
+{
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIPrefBranch> prefBranch;
+  nsCOMPtr<nsIPrefLocalizedString> pls;
+  nsString ucsval;
+
+  prefBranch = do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = prefBranch->GetComplexValue(aPrefName, NS_GET_IID(nsIPrefLocalizedString), getter_AddRefs(pls));
+  NS_ENSURE_SUCCESS(rv, rv);
+  pls->ToString(getter_Copies(ucsval));
+  aResult = ucsval.get();
+  return rv;
+}
+
+nsresult nsMsgDBView::AppendKeywordProperties(const nsACString& keywords, nsAString& properties, bool addSelectedTextProperty)
+{
+  // get the top most keyword's color and append that as a property.
+  nsresult rv;
+  if (!mTagService)
+  {
+    mTagService = do_GetService(NS_MSGTAGSERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  nsCString topKey;
+  rv = mTagService->GetTopKey(keywords, topKey);
+  NS_ENSURE_SUCCESS(rv, rv);
+  if (topKey.IsEmpty())
+    return NS_OK;
+
+  nsCString color;
+  rv = mTagService->GetColorForKey(topKey, color);
+  if (NS_SUCCEEDED(rv) && !color.IsEmpty())
+  {
+    if (addSelectedTextProperty)
+    {
+      if (color.EqualsLiteral(LABEL_COLOR_WHITE_STRING))
+        properties.AppendLiteral(" lc-black");
+      else
+        properties.AppendLiteral(" lc-white");
+    }
+    color.Replace(0, 1, NS_LITERAL_CSTRING(LABEL_COLOR_STRING));
+    properties.AppendASCII(color.get());
+  }
+  return rv;
+}
+
+///////////////////////////////////////////////////////////////////////////
+// nsITreeView Implementation Methods (and helper methods)
+///////////////////////////////////////////////////////////////////////////
+
+static nsresult GetDisplayNameInAddressBook(const nsACString& emailAddress,
+                                            nsAString& displayName)
+{
+  nsresult rv;
+  nsCOMPtr<nsIAbManager> abManager(do_GetService("@mozilla.org/abmanager;1",
+                                   &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsISimpleEnumerator> enumerator;
+  rv = abManager->GetDirectories(getter_AddRefs(enumerator));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsISupports> supports;
+  nsCOMPtr<nsIAbDirectory> directory;
+  nsCOMPtr<nsIAbCard> cardForAddress;
+  bool hasMore;
+
+  // Scan the addressbook to find out the card of the email address
+  while (NS_SUCCEEDED(enumerator->HasMoreElements(&hasMore)) &&
+         hasMore && !cardForAddress)
+  {
+    rv = enumerator->GetNext(getter_AddRefs(supports));
+    NS_ENSURE_SUCCESS(rv, rv);
+    directory = do_QueryInterface(supports);
+    if (directory)
+    {
+      rv = directory->CardForEmailAddress(emailAddress,
+                        getter_AddRefs(cardForAddress));
+
+      if (NS_SUCCEEDED(rv) && cardForAddress)
+        break; // the card is found,so stop looping
+    }
+  }
+
+  if (cardForAddress)
+  {
+    bool preferDisplayName = true;
+    cardForAddress->GetPropertyAsBool("PreferDisplayName",&preferDisplayName);
+
+    if (preferDisplayName)
+      rv = cardForAddress->GetDisplayName(displayName);
+  }
+
+  return rv;
+}
+
+/* The unparsedString has following format
+ * "version|displayname"
+ */
+static void GetCachedName(const nsCString& unparsedString,
+                          int32_t displayVersion, nsACString& cachedName)
+{
+  nsresult err;
+
+  //get verion #
+  int32_t cachedVersion = unparsedString.ToInteger(&err);
+  if (cachedVersion != displayVersion)
+    return;
+
+  //get cached name
+  int32_t pos = unparsedString.FindChar('|');
+  if (pos != kNotFound)
+    cachedName = Substring(unparsedString, pos + 1);
+}
+
+static void UpdateCachedName(nsIMsgDBHdr *aHdr, const char *header_field,
+                             const nsAString& newName)
+{
+  nsCString newCachedName;
+  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
+  int32_t  currentDisplayNameVersion = 0;
+
+  prefs->GetIntPref("mail.displayname.version", &currentDisplayNameVersion);
+
+  // save version number
+  newCachedName.AppendInt(currentDisplayNameVersion);
+  newCachedName.Append("|");
+
+  // save name
+  newCachedName.Append(NS_ConvertUTF16toUTF8(newName));
+
+  aHdr->SetStringProperty(header_field,newCachedName.get());
+}
+
+nsresult nsMsgDBView::FetchAuthor(nsIMsgDBHdr * aHdr, nsAString &aSenderString)
+{
+  nsCString unparsedAuthor;
+  bool showCondensedAddresses = false;
+  int32_t  currentDisplayNameVersion = 0;
+  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
+
+  prefs->GetIntPref("mail.displayname.version", &currentDisplayNameVersion);
+  prefs->GetBoolPref("mail.showCondensedAddresses", &showCondensedAddresses);
+
+  aHdr->GetStringProperty("sender_name", getter_Copies(unparsedAuthor));
+
+  // if the author is already computed, use it
+  if (!unparsedAuthor.IsEmpty())
+  {
+    nsCString cachedDisplayName;
+
+    GetCachedName(unparsedAuthor, currentDisplayNameVersion, cachedDisplayName);
+    if (!cachedDisplayName.IsEmpty())
+    {
+      CopyUTF8toUTF16(cachedDisplayName, aSenderString);
+      return NS_OK;
+    }
+  }
+
+  nsCString author;
+  (void) aHdr->GetAuthor(getter_Copies(author));
+
+  nsCString headerCharset;
+  aHdr->GetEffectiveCharset(headerCharset);
+
+  nsCString emailAddress;
+  nsString name;
+  ExtractFirstAddress(EncodedHeader(author, headerCharset.get()), name,
+    emailAddress);
+
+  if (showCondensedAddresses)
+    GetDisplayNameInAddressBook(emailAddress, aSenderString);
+
+  if (aSenderString.IsEmpty())
+  {
+     // We can't use the display name in the card; use the name contained in
+     // the header or email address.
+    if (name.IsEmpty()) {
+      CopyUTF8toUTF16(emailAddress, aSenderString);
+    } else {
+      int32_t atPos;
+      if ((atPos = name.FindChar('@')) == kNotFound ||
+          name.FindChar('.', atPos) == kNotFound) {
+        aSenderString = name;
+      } else {
+        // Found @ followed by a dot, so this looks like a spoofing case.
+        aSenderString = name;
+        aSenderString.AppendLiteral(" <");
+        AppendUTF8toUTF16(emailAddress, aSenderString);
+        aSenderString.Append('>');
+      }
+    }
+  }
+
+  UpdateCachedName(aHdr, "sender_name", aSenderString);
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::FetchAccount(nsIMsgDBHdr * aHdr, nsAString& aAccount)
+{
+  nsCString accountKey;
+
+  nsresult rv = aHdr->GetAccountKey(getter_Copies(accountKey));
+
+  // Cache the account manager?
+  nsCOMPtr<nsIMsgAccountManager> accountManager(
+    do_GetService(NS_MSGACCOUNTMANAGER_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIMsgAccount> account;
+  nsCOMPtr<nsIMsgIncomingServer> server;
+  if (!accountKey.IsEmpty())
+    rv = accountManager->GetAccount(accountKey, getter_AddRefs(account));
+
+  if (account)
+  {
+    account->GetIncomingServer(getter_AddRefs(server));
+  }
+  else
+  {
+    nsCOMPtr<nsIMsgFolder> folder;
+    aHdr->GetFolder(getter_AddRefs(folder));
+    if (folder)
+     folder->GetServer(getter_AddRefs(server));
+  }
+  if (server)
+    server->GetPrettyName(aAccount);
+  else
+    CopyASCIItoUTF16(accountKey, aAccount);
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::FetchRecipients(nsIMsgDBHdr * aHdr, nsAString &aRecipientsString)
+{
+  nsCString recipients;
+  int32_t currentDisplayNameVersion = 0;
+  bool showCondensedAddresses = false;
+  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
+
+  prefs->GetIntPref("mail.displayname.version", &currentDisplayNameVersion);
+  prefs->GetBoolPref("mail.showCondensedAddresses", &showCondensedAddresses);
+
+  aHdr->GetStringProperty("recipient_names", getter_Copies(recipients));
+
+  if (!recipients.IsEmpty())
+  {
+    nsCString cachedRecipients;
+
+    GetCachedName(recipients, currentDisplayNameVersion, cachedRecipients);
+
+    // recipients have already been cached,check if the addressbook
+    // was changed after cache.
+    if (!cachedRecipients.IsEmpty())
+    {
+      CopyUTF8toUTF16(cachedRecipients, aRecipientsString);
+      return NS_OK;
+    }
+  }
+
+  nsCString unparsedRecipients;
+  nsresult rv = aHdr->GetRecipients(getter_Copies(unparsedRecipients));
+
+  nsCString headerCharset;
+  aHdr->GetEffectiveCharset(headerCharset);
+
+  nsTArray<nsString> names;
+  nsTArray<nsCString> emails;
+  ExtractAllAddresses(EncodedHeader(unparsedRecipients, headerCharset.get()),
+    names, UTF16ArrayAdapter<>(emails));
+
+  uint32_t numAddresses = names.Length();
+
+  nsCOMPtr<nsISimpleEnumerator> enumerator;
+  nsCOMPtr<nsIAbManager>
+    abManager(do_GetService("@mozilla.org/abmanager;1", &rv));
+  NS_ENSURE_SUCCESS(rv, NS_OK);
+
+  // go through each email address in the recipients and
+  // compute its display name.
+  for (uint32_t i = 0; i < numAddresses; i++)
+  {
+    nsString recipient;
+    nsCString &curAddress = emails[i];
+    nsString &curName = names[i];
+
+    if (showCondensedAddresses)
+      GetDisplayNameInAddressBook(curAddress, recipient);
+
+    if (recipient.IsEmpty())
+    {
+      // we can't use the display name in the card,
+      // use the name contained in the header or email address.
+      if (curName.IsEmpty()) {
+        CopyUTF8toUTF16(curAddress, recipient);
+      } else {
+        int32_t atPos;
+        if ((atPos = curName.FindChar('@')) == kNotFound ||
+            curName.FindChar('.', atPos) == kNotFound) {
+          recipient = curName;
+        } else {
+          // Found @ followed by a dot, so this looks like a spoofing case.
+          recipient = curName;
+          recipient.AppendLiteral(" <");
+          AppendUTF8toUTF16(curAddress, recipient);
+          recipient.Append('>');
+        }
+      }
+    }
+
+    // add ', ' between each recipient
+    if (i != 0)
+      aRecipientsString.Append(NS_LITERAL_STRING(", "));
+
+    aRecipientsString.Append(recipient);
+  }
+
+  if (numAddresses == 0 && unparsedRecipients.FindChar(':') != kNotFound) {
+    // No addresses and a colon, so an empty group like "undisclosed-recipients: ;".
+    // Add group name so at least something displays.
+    nsString group;
+    CopyUTF8toUTF16(unparsedRecipients, group);
+    aRecipientsString.Assign(group);
+  }
+
+  UpdateCachedName(aHdr, "recipient_names", aRecipientsString);
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::FetchSubject(nsIMsgDBHdr * aMsgHdr, uint32_t aFlags, nsAString &aValue)
+{
+  if (aFlags & nsMsgMessageFlags::HasRe)
+  {
+    nsString subject;
+    aMsgHdr->GetMime2DecodedSubject(subject);
+    aValue.AssignLiteral("Re: ");
+    aValue.Append(subject);
+  }
+  else
+    aMsgHdr->GetMime2DecodedSubject(aValue);
+  return NS_OK;
+}
+
+// in case we want to play around with the date string, I've broken it out into
+// a separate routine.  Set rcvDate to true to get the Received: date instead
+// of the Date: date.
+nsresult nsMsgDBView::FetchDate(nsIMsgDBHdr * aHdr, nsAString &aDateString, bool rcvDate)
+{
+  PRTime dateOfMsg;
+  PRTime dateOfMsgLocal;
+  uint32_t rcvDateSecs;
+  nsresult rv;
+
+  if (!mDateFormatter)
+    mDateFormatter = do_CreateInstance(NS_DATETIMEFORMAT_CONTRACTID);
+
+  NS_ENSURE_TRUE(mDateFormatter, NS_ERROR_FAILURE);
+  // Silently return Date: instead if Received: is unavailable
+  if (rcvDate)
+  {
+    rv = aHdr->GetUint32Property("dateReceived", &rcvDateSecs);
+    if (rcvDateSecs != 0)
+      Seconds2PRTime(rcvDateSecs, &dateOfMsg);
+  }
+  if (!rcvDate || rcvDateSecs == 0)
+    rv = aHdr->GetDate(&dateOfMsg);
+
+  PRTime currentTime = PR_Now();
+  PRExplodedTime explodedCurrentTime;
+  PR_ExplodeTime(currentTime, PR_LocalTimeParameters, &explodedCurrentTime);
+  PRExplodedTime explodedMsgTime;
+  PR_ExplodeTime(dateOfMsg, PR_LocalTimeParameters, &explodedMsgTime);
+
+  // if the message is from today, don't show the date, only the time. (i.e. 3:15 pm)
+  // if the message is from the last week, show the day of the week.   (i.e. Mon 3:15 pm)
+  // in all other cases, show the full date (03/19/01 3:15 pm)
+
+  nsDateFormatSelector dateFormat = m_dateFormatDefault;
+  if (explodedCurrentTime.tm_year == explodedMsgTime.tm_year &&
+      explodedCurrentTime.tm_month == explodedMsgTime.tm_month &&
+      explodedCurrentTime.tm_mday == explodedMsgTime.tm_mday)
+  {
+    // same day...
+    dateFormat = m_dateFormatToday;
+  }
+  // the following chunk of code allows us to show a day instead of a number if the message was received
+  // within the last 7 days. i.e. Mon 5:10pm. (depending on the mail.ui.display.dateformat.thisweek pref)
+  // The concrete format used is dependent on a preference setting (see InitDisplayFormats).
+  else if (currentTime > dateOfMsg)
+  {
+    // Convert the times from GMT to local time
+    int64_t GMTLocalTimeShift = PR_USEC_PER_SEC *
+      int64_t(explodedCurrentTime.tm_params.tp_gmt_offset +
+       explodedCurrentTime.tm_params.tp_dst_offset);
+    currentTime += GMTLocalTimeShift;
+    dateOfMsgLocal = dateOfMsg + GMTLocalTimeShift;
+
+    // Find the most recent midnight
+    int64_t todaysMicroSeconds = currentTime % PR_USEC_PER_DAY;
+    int64_t mostRecentMidnight = currentTime - todaysMicroSeconds;
+
+    // most recent midnight minus 6 days
+    int64_t mostRecentWeek = mostRecentMidnight - (PR_USEC_PER_DAY * 6);
+
+    // was the message sent during the last week?
+    if (dateOfMsgLocal >= mostRecentWeek)
+    { // yes ....
+      dateFormat = m_dateFormatThisWeek;
+    }
+  }
+
+  if (NS_SUCCEEDED(rv))
+    rv = mDateFormatter->FormatPRTime(nullptr /* nsILocale* locale */,
+                                      dateFormat,
+                                      kTimeFormatNoSeconds,
+                                      dateOfMsg,
+                                      aDateString);
+
+  return rv;
+}
+
+nsresult nsMsgDBView::FetchStatus(uint32_t aFlags, nsAString &aStatusString)
+{
+  if (aFlags & nsMsgMessageFlags::Replied)
+    aStatusString = kRepliedString;
+  else if (aFlags & nsMsgMessageFlags::Forwarded)
+    aStatusString = kForwardedString;
+  else if (aFlags & nsMsgMessageFlags::New)
+    aStatusString = kNewString;
+  else if (aFlags & nsMsgMessageFlags::Read)
+    aStatusString = kReadString;
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::FetchSize(nsIMsgDBHdr * aHdr, nsAString &aSizeString)
+{
+  nsresult rv;
+  nsAutoString formattedSizeString;
+  uint32_t msgSize = 0;
+
+  // for news, show the line count, not the size if the user wants so
+  if (mShowSizeInLines)
+  {
+    aHdr->GetLineCount(&msgSize);
+    formattedSizeString.AppendInt(msgSize);
+  }
+  else
+  {
+    uint32_t flags = 0;
+
+    aHdr->GetFlags(&flags);
+    if (flags & nsMsgMessageFlags::Partial)
+      aHdr->GetUint32Property("onlineSize", &msgSize);
+
+    if (msgSize == 0)
+      aHdr->GetMessageSize(&msgSize);
+
+    rv = FormatFileSize(msgSize, true, formattedSizeString);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  aSizeString = formattedSizeString;
+  // the formattingString Length includes the null terminator byte!
+  if (!formattedSizeString.Last())
+    aSizeString.SetLength(formattedSizeString.Length() - 1);
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::FetchPriority(nsIMsgDBHdr *aHdr, nsAString & aPriorityString)
+{
+  nsMsgPriorityValue priority = nsMsgPriority::notSet;
+  aHdr->GetPriority(&priority);
+
+  switch (priority)
+  {
+  case nsMsgPriority::highest:
+    aPriorityString = kHighestPriorityString;
+    break;
+  case nsMsgPriority::high:
+    aPriorityString = kHighPriorityString;
+    break;
+  case nsMsgPriority::low:
+    aPriorityString = kLowPriorityString;
+    break;
+  case nsMsgPriority::lowest:
+    aPriorityString = kLowestPriorityString;
+    break;
+  case nsMsgPriority::normal:
+    aPriorityString = kNormalPriorityString;
+    break;
+  default:
+    break;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::FetchKeywords(nsIMsgDBHdr *aHdr, nsACString &keywordString)
+{
+  NS_ENSURE_ARG_POINTER(aHdr);
+  nsresult rv = NS_OK;
+  if (!mTagService)
+  {
+    mTagService = do_GetService(NS_MSGTAGSERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  nsMsgLabelValue label = 0;
+
+  rv = aHdr->GetLabel(&label);
+  nsCString keywords;
+  aHdr->GetStringProperty("keywords", getter_Copies(keywords));
+  if (label > 0)
+  {
+    nsAutoCString labelStr("$label");
+    labelStr.Append((char) (label + '0'));
+    if (keywords.Find(labelStr, CaseInsensitiveCompare) == -1)
+    {
+      if (!keywords.IsEmpty())
+        keywords.Append(' ');
+      keywords.Append(labelStr);
+    }
+  }
+  keywordString = keywords;
+  return NS_OK;
+}
+
+// If the row is a collapsed thread, we optionally roll-up the keywords in all
+// the messages in the thread, otherwise, return just the keywords for the row.
+nsresult nsMsgDBView::FetchRowKeywords(nsMsgViewIndex aRow, nsIMsgDBHdr *aHdr,
+                                       nsACString &keywordString)
+{
+  nsresult rv = FetchKeywords(aHdr,keywordString);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool cascadeKeywordsUp = true;
+  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
+  prefs->GetBoolPref("mailnews.display_reply_tag_colors_for_collapsed_threads",
+                     &cascadeKeywordsUp);
+
+  if ((m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) &&
+      cascadeKeywordsUp)
+  {
+    if ((m_flags[aRow] & MSG_VIEW_FLAG_ISTHREAD)
+        && (m_flags[aRow] & nsMsgMessageFlags::Elided))
+    {
+      nsCOMPtr<nsIMsgThread> thread;
+      rv = GetThreadContainingIndex(aRow, getter_AddRefs(thread));
+      if (NS_SUCCEEDED(rv) && thread)
+      {
+        uint32_t numChildren;
+        thread->GetNumChildren(&numChildren);
+        nsCOMPtr<nsIMsgDBHdr> msgHdr;
+        nsCString moreKeywords;
+        for (uint32_t index = 0; index < numChildren; index++)
+        {
+          thread->GetChildHdrAt(index, getter_AddRefs(msgHdr));
+          rv = FetchKeywords(msgHdr, moreKeywords);
+          NS_ENSURE_SUCCESS(rv, rv);
+
+          if (!keywordString.IsEmpty() && !moreKeywords.IsEmpty())
+            keywordString.Append(' ');
+          keywordString.Append(moreKeywords);
+        }
+      }
+    }
+  }
+  return rv;
+}
+
+nsresult nsMsgDBView::FetchTags(nsIMsgDBHdr *aHdr, nsAString &aTagString)
+{
+  NS_ENSURE_ARG_POINTER(aHdr);
+  nsresult rv = NS_OK;
+  if (!mTagService)
+  {
+    mTagService = do_GetService(NS_MSGTAGSERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  nsString tags;
+  nsCString keywords;
+  aHdr->GetStringProperty("keywords", getter_Copies(keywords));
+
+  nsMsgLabelValue label = 0;
+  rv = aHdr->GetLabel(&label);
+  if (label > 0)
+  {
+    nsAutoCString labelStr("$label");
+    labelStr.Append((char) (label + '0'));
+    if (keywords.Find(labelStr, CaseInsensitiveCompare) == -1)
+      FetchLabel(aHdr, tags);
+  }
+
+  nsTArray<nsCString> keywordsArray;
+  ParseString(keywords, ' ', keywordsArray);
+  nsAutoString tag;
+
+  for (uint32_t i = 0; i < keywordsArray.Length(); i++)
+  {
+    rv = mTagService->GetTagForKey(keywordsArray[i], tag);
+    if (NS_SUCCEEDED(rv) && !tag.IsEmpty())
+    {
+      if (!tags.IsEmpty())
+        tags.Append((char16_t) ' ');
+      tags.Append(tag);
+    }
+  }
+
+  aTagString = tags;
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::FetchLabel(nsIMsgDBHdr *aHdr, nsAString &aLabelString)
+{
+  nsresult rv = NS_OK;
+  nsMsgLabelValue label = 0;
+
+  NS_ENSURE_ARG_POINTER(aHdr);
+
+  rv = aHdr->GetLabel(&label);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // we don't care if label is not between 1 and PREF_LABELS_MAX inclusive.
+  if ((label < 1) || (label > PREF_LABELS_MAX))
+  {
+    aLabelString.Truncate();
+    return NS_OK;
+  }
+
+  // We need to subtract 1 because mLabelPrefDescriptions is 0 based.
+  aLabelString = mLabelPrefDescriptions[label - 1];
+  return NS_OK;
+}
+
+bool nsMsgDBView::IsOutgoingMsg(nsIMsgDBHdr* aHdr)
+{
+  nsString author;
+  aHdr->GetMime2DecodedAuthor(author);
+
+  nsCString emailAddress;
+  nsString name;
+  ExtractFirstAddress(DecodedHeader(author), name, emailAddress);
+
+  return mEmails.Contains(emailAddress);
+}
+
+
+/*if you call SaveAndClearSelection make sure to call RestoreSelection otherwise
+m_saveRestoreSelectionDepth will be incorrect and will lead to selection msg problems*/
+
+nsresult nsMsgDBView::SaveAndClearSelection(nsMsgKey *aCurrentMsgKey, nsTArray<nsMsgKey> &aMsgKeyArray)
+{
+  // we don't do anything on nested Save / Restore calls.
+  m_saveRestoreSelectionDepth++;
+  if (m_saveRestoreSelectionDepth != 1)
+    return NS_OK;
+
+  if (!mTreeSelection || !mTree)
+    return NS_OK;
+
+  // first, freeze selection.
+  mTreeSelection->SetSelectEventsSuppressed(true);
+
+  // second, save the current index.
+  if (aCurrentMsgKey)
+  {
+    int32_t currentIndex;
+    if (NS_SUCCEEDED(mTreeSelection->GetCurrentIndex(&currentIndex)) &&
+        currentIndex >= 0 && uint32_t(currentIndex) < GetSize())
+      *aCurrentMsgKey = m_keys[currentIndex];
+    else
+      *aCurrentMsgKey = nsMsgKey_None;
+  }
+
+  // third, get an array of view indices for the selection.
+  nsMsgViewIndexArray selection;
+  GetSelectedIndices(selection);
+  int32_t numIndices = selection.Length();
+  aMsgKeyArray.SetLength(numIndices);
+
+  // now store the msg key for each selected item.
+  nsMsgKey msgKey;
+  for (int32_t index = 0; index < numIndices; index++)
+  {
+    msgKey = m_keys[selection[index]];
+    aMsgKeyArray[index] = msgKey;
+  }
+
+  // clear the selection, we'll manually restore it later.
+  if (mTreeSelection)
+    mTreeSelection->ClearSelection();
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::RestoreSelection(nsMsgKey aCurrentMsgKey, nsTArray<nsMsgKey> &aMsgKeyArray)
+{
+  // we don't do anything on nested Save / Restore calls.
+  m_saveRestoreSelectionDepth--;
+  if (m_saveRestoreSelectionDepth)
+    return NS_OK;
+
+  if (!mTreeSelection)  // don't assert.
+    return NS_OK;
+
+  // turn our message keys into corresponding view indices
+  int32_t arraySize = aMsgKeyArray.Length();
+  nsMsgViewIndex  currentViewPosition = nsMsgViewIndex_None;
+  nsMsgViewIndex  newViewPosition = nsMsgViewIndex_None;
+
+  // if we are threaded, we need to do a little more work
+  // we need to find (and expand) all the threads that contain messages
+  // that we had selected before.
+  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+  {
+    for (int32_t index = 0; index < arraySize; index ++)
+    {
+      FindKey(aMsgKeyArray[index], true /* expand */);
+    }
+  }
+
+  for (int32_t index = 0; index < arraySize; index ++)
+  {
+    newViewPosition = FindKey(aMsgKeyArray[index], false);
+    // add the index back to the selection.
+    if (newViewPosition != nsMsgViewIndex_None)
+      mTreeSelection->ToggleSelect(newViewPosition);
+  }
+
+  // make sure the currentView was preserved....
+  if (aCurrentMsgKey != nsMsgKey_None)
+    currentViewPosition = FindKey(aCurrentMsgKey, true);
+
+  if (mTree)
+    mTreeSelection->SetCurrentIndex(currentViewPosition);
+
+  // make sure the current message is once again visible in the thread pane
+  // so we don't have to go search for it in the thread pane
+  if (mTree && currentViewPosition != nsMsgViewIndex_None)
+    mTree->EnsureRowIsVisible(currentViewPosition);
+
+  // unfreeze selection.
+  mTreeSelection->SetSelectEventsSuppressed(false);
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::GenerateURIForMsgKey(nsMsgKey aMsgKey, nsIMsgFolder *folder, nsACString & aURI)
+{
+  NS_ENSURE_ARG(folder);
+  return folder->GenerateMessageURI(aMsgKey, aURI);
+}
+
+nsresult nsMsgDBView::GetMessageEnumerator(nsISimpleEnumerator **enumerator)
+{
+  return m_db->EnumerateMessages(enumerator);
+}
+
+nsresult nsMsgDBView::CycleThreadedColumn(nsIDOMElement * aElement)
+{
+  nsAutoString currentView;
+
+  // toggle threaded/unthreaded mode
+  aElement->GetAttribute(NS_LITERAL_STRING("currentView"), currentView);
+  if (currentView.EqualsLiteral("threaded"))
+    aElement->SetAttribute(NS_LITERAL_STRING("currentView"), NS_LITERAL_STRING("unthreaded"));
+  else
+     aElement->SetAttribute(NS_LITERAL_STRING("currentView"), NS_LITERAL_STRING("threaded"));
+
+  // i think we need to create a new view and switch it in this circumstance since
+  // we are toggline between threaded and non threaded mode.
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::IsEditable(int32_t row, nsITreeColumn* col, bool* _retval)
+{
+  NS_ENSURE_ARG_POINTER(col);
+  NS_ENSURE_ARG_POINTER(_retval);
+  //attempt to retreive a custom column handler. If it exists call it and return
+  const char16_t* colID;
+  col->GetIdConst(&colID);
+
+  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);
+
+  if (colHandler)
+  {
+    colHandler->IsEditable(row, col, _retval);
+    return NS_OK;
+  }
+
+  *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::IsSelectable(int32_t row, nsITreeColumn* col, bool* _retval)
+{
+  *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetCellValue(int32_t row, nsITreeColumn* col, const nsAString& value)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetCellText(int32_t row, nsITreeColumn* col, const nsAString& value)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetRowCount(int32_t *aRowCount)
+{
+  *aRowCount = GetSize();
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSelection(nsITreeSelection * *aSelection)
+{
+  *aSelection = mTreeSelection;
+  NS_IF_ADDREF(*aSelection);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetSelection(nsITreeSelection * aSelection)
+{
+  mTreeSelection = aSelection;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::ReloadMessageWithAllParts()
+{
+  if (m_currentlyDisplayedMsgUri.IsEmpty() || mSuppressMsgDisplay)
+    return NS_OK;
+
+  nsAutoCString forceAllParts(m_currentlyDisplayedMsgUri);
+  forceAllParts += (forceAllParts.FindChar('?') == kNotFound) ? '?' : '&';
+  forceAllParts.AppendLiteral("fetchCompleteMessage=true");
+  nsCOMPtr<nsIMessenger> messenger (do_QueryReferent(mMessengerWeak));
+  NS_ENSURE_TRUE(messenger, NS_ERROR_FAILURE);
+
+  nsresult rv = messenger->OpenURL(forceAllParts);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  UpdateDisplayMessage(m_currentlyDisplayedViewIndex);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::ReloadMessage()
+{
+  if (m_currentlyDisplayedMsgUri.IsEmpty() || mSuppressMsgDisplay)
+    return NS_OK;
+  nsCOMPtr<nsIMessenger> messenger (do_QueryReferent(mMessengerWeak));
+  NS_ENSURE_TRUE(messenger, NS_ERROR_FAILURE);
+
+  nsresult rv = messenger->OpenURL(m_currentlyDisplayedMsgUri);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  UpdateDisplayMessage(m_currentlyDisplayedViewIndex);
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::UpdateDisplayMessage(nsMsgViewIndex viewPosition)
+{
+  nsresult rv;
+  if (mCommandUpdater)
+  {
+    // get the subject and the folder for the message and inform the front end that
+    // we changed the message we are currently displaying.
+    if (viewPosition != nsMsgViewIndex_None)
+    {
+      nsCOMPtr <nsIMsgDBHdr> msgHdr;
+      rv = GetMsgHdrForViewIndex(viewPosition, getter_AddRefs(msgHdr));
+      NS_ENSURE_SUCCESS(rv,rv);
+
+      nsString subject;
+      FetchSubject(msgHdr, m_flags[viewPosition], subject);
+
+      nsCString keywords;
+      rv = msgHdr->GetStringProperty("keywords", getter_Copies(keywords));
+      NS_ENSURE_SUCCESS(rv,rv);
+
+      nsCOMPtr<nsIMsgFolder> folder = m_viewFolder ? m_viewFolder : m_folder;
+
+      mCommandUpdater->DisplayMessageChanged(folder, subject, keywords);
+
+      if (folder)
+      {
+        rv = folder->SetLastMessageLoaded(m_keys[viewPosition]);
+        NS_ENSURE_SUCCESS(rv,rv);
+      }
+    } // if view position is valid
+  } // if we have an updater
+  return NS_OK;
+}
+
+// given a msg key, we will load the message for it.
+NS_IMETHODIMP nsMsgDBView::LoadMessageByMsgKey(nsMsgKey aMsgKey)
+{
+  return LoadMessageByViewIndex(FindKey(aMsgKey, false));
+}
+
+NS_IMETHODIMP nsMsgDBView::LoadMessageByViewIndex(nsMsgViewIndex aViewIndex)
+{
+  NS_ASSERTION(aViewIndex != nsMsgViewIndex_None,"trying to load nsMsgViewIndex_None");
+  if (aViewIndex == nsMsgViewIndex_None) return NS_ERROR_UNEXPECTED;
+
+  nsCString uri;
+  nsresult rv = GetURIForViewIndex(aViewIndex, uri);
+  if (!mSuppressMsgDisplay && !m_currentlyDisplayedMsgUri.Equals(uri))
+  {
+    NS_ENSURE_SUCCESS(rv,rv);
+    nsCOMPtr<nsIMessenger> messenger (do_QueryReferent(mMessengerWeak));
+    NS_ENSURE_TRUE(messenger, NS_ERROR_FAILURE);
+    messenger->OpenURL(uri);
+    m_currentlyDisplayedMsgKey = m_keys[aViewIndex];
+    m_currentlyDisplayedMsgUri = uri;
+    m_currentlyDisplayedViewIndex = aViewIndex;
+    UpdateDisplayMessage(m_currentlyDisplayedViewIndex);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::LoadMessageByUrl(const char *aUrl)
+{
+  NS_ASSERTION(aUrl, "trying to load a null url");
+  if (!mSuppressMsgDisplay)
+  {
+    nsresult rv;
+    nsCOMPtr<nsIMessenger> messenger (do_QueryReferent(mMessengerWeak, &rv));
+    NS_ENSURE_SUCCESS(rv, rv);
+    messenger->LoadURL(NULL, nsDependentCString(aUrl));
+    m_currentlyDisplayedMsgKey = nsMsgKey_None;
+    m_currentlyDisplayedMsgUri = aUrl;
+    m_currentlyDisplayedViewIndex = nsMsgViewIndex_None;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SelectionChanged()
+{
+  // if the currentSelection changed then we have a message to display - not if we are in the middle of deleting rows
+  if (m_deletingRows)
+    return NS_OK;
+
+  uint32_t numSelected = 0;
+
+  nsMsgViewIndexArray selection;
+  GetSelectedIndices(selection);
+  nsMsgViewIndex *indices = selection.Elements();
+  numSelected = selection.Length();
+
+  bool commandsNeedDisablingBecauseOfSelection = false;
+
+  if(indices)
+  {
+    if (WeAreOffline())
+      commandsNeedDisablingBecauseOfSelection = !OfflineMsgSelected(indices, numSelected);
+    if (!NonDummyMsgSelected(indices, numSelected))
+      commandsNeedDisablingBecauseOfSelection = true;
+  }
+  bool selectionSummarized = false;
+  mSummarizeFailed = false;
+  // let the front-end adjust the message pane appropriately with either
+  // the message body, or a summary of the selection
+  if (mCommandUpdater)
+  {
+    mCommandUpdater->SummarizeSelection(&selectionSummarized);
+    // check if the selection was not summarized, but we expected it to be,
+    // and if so, remember it so GetHeadersFromSelection won't include
+    // the messages in collapsed threads.
+    if (!selectionSummarized &&
+        (numSelected > 1 || (numSelected == 1 &&
+                              m_flags[indices[0]] & nsMsgMessageFlags::Elided &&
+                              OperateOnMsgsInCollapsedThreads())))
+      mSummarizeFailed = true;
+  }
+
+  bool summaryStateChanged = selectionSummarized != mSelectionSummarized;
+
+  mSelectionSummarized = selectionSummarized;
+  // if only one item is selected then we want to display a message
+  if (mTreeSelection && numSelected == 1 && !selectionSummarized)
+  {
+    int32_t startRange;
+    int32_t endRange;
+    nsresult rv = mTreeSelection->GetRangeAt(0, &startRange, &endRange);
+    NS_ENSURE_SUCCESS(rv, NS_OK); // tree doesn't care if we failed
+
+    if (startRange >= 0 && startRange == endRange &&
+        uint32_t(startRange) < GetSize())
+    {
+      if (!mRemovingRow)
+      {
+        if (!mSuppressMsgDisplay)
+          LoadMessageByViewIndex(startRange);
+        else
+          UpdateDisplayMessage(startRange);
+      }
+    }
+    else
+      numSelected = 0; // selection seems bogus, so set to 0.
+  }
+  else {
+    // if we have zero or multiple items selected, we shouldn't be displaying any message
+    m_currentlyDisplayedMsgKey = nsMsgKey_None;
+    m_currentlyDisplayedMsgUri.Truncate();
+    m_currentlyDisplayedViewIndex = nsMsgViewIndex_None;
+  }
+
+  // determine if we need to push command update notifications out to the UI or not.
+
+  // we need to push a command update notification iff, one of the following conditions are met
+  // (1) the selection went from 0 to 1
+  // (2) it went from 1 to 0
+  // (3) it went from 1 to many
+  // (4) it went from many to 1 or 0
+  // (5) a different msg was selected - perhaps it was offline or not...matters only when we are offline
+  // (6) we did a forward/back, or went from having no history to having history - not sure how to tell this.
+  // (7) whether the selection was summarized or not changed.
+
+  // I think we're going to need to keep track of whether forward/back were enabled/should be enabled,
+  // and when this changes, force a command update.
+
+  bool enableGoForward = false;
+  bool enableGoBack = false;
+
+  NavigateStatus(nsMsgNavigationType::forward, &enableGoForward);
+  NavigateStatus(nsMsgNavigationType::back, &enableGoBack);
+  if (!summaryStateChanged &&
+      (numSelected == mNumSelectedRows ||
+      (numSelected > 1 && mNumSelectedRows > 1)) && (commandsNeedDisablingBecauseOfSelection == mCommandsNeedDisablingBecauseOfSelection)
+      && enableGoForward == mGoForwardEnabled && enableGoBack == mGoBackEnabled)
+  {
+  }
+  // don't update commands if we're suppressing them, or if we're removing rows, unless it was the last row.
+  else if (!mSuppressCommandUpdating && mCommandUpdater && (!mRemovingRow || GetSize() == 0)) // o.t. push an updated
+  {
+    mCommandUpdater->UpdateCommandStatus();
+  }
+
+  mCommandsNeedDisablingBecauseOfSelection = commandsNeedDisablingBecauseOfSelection;
+  mGoForwardEnabled = enableGoForward;
+  mGoBackEnabled = enableGoBack;
+  mNumSelectedRows = numSelected;
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::GetSelectedIndices(nsMsgViewIndexArray& selection)
+{
+  if (mTreeSelection)
+  {
+    int32_t viewSize = GetSize();
+    int32_t count;
+    mTreeSelection->GetCount(&count);
+    selection.SetLength(count);
+    count = 0;
+    int32_t selectionCount;
+    mTreeSelection->GetRangeCount(&selectionCount);
+    for (int32_t i = 0; i < selectionCount; i++)
+    {
+      int32_t startRange = -1;
+      int32_t endRange = -1;
+      mTreeSelection->GetRangeAt(i, &startRange, &endRange);
+      if (startRange >= 0 && startRange < viewSize)
+      {
+        for (int32_t rangeIndex = startRange; rangeIndex <= endRange && rangeIndex < viewSize; rangeIndex++)
+          selection[count++] = rangeIndex;
+      }
+    }
+    NS_ASSERTION(selection.Length() == uint32_t(count), "selection count is wrong");
+    selection.SetLength(count);
+  }
+  else
+  {
+    // if there is no tree selection object then we must be in stand alone message mode.
+    // in that case the selected indices are really just the current message key.
+    nsMsgViewIndex viewIndex = FindViewIndex(m_currentlyDisplayedMsgKey);
+    if (viewIndex != nsMsgViewIndex_None)
+      selection.AppendElement(viewIndex);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetRowProperties(int32_t index, nsAString& properties)
+{
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  // this is where we tell the tree to apply styles to a particular row
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  nsresult rv = NS_OK;
+
+  rv = GetMsgHdrForViewIndex(index, getter_AddRefs(msgHdr));
+
+  if (NS_FAILED(rv) || !msgHdr) {
+    ClearHdrCache();
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  }
+
+  nsCString keywordProperty;
+  FetchRowKeywords(index, msgHdr, keywordProperty);
+  if (!keywordProperty.IsEmpty())
+    AppendKeywordProperties(keywordProperty, properties, false);
+
+  // give the custom column handlers a chance to style the row.
+  for (int i = 0; i < m_customColumnHandlers.Count(); i++)
+  {
+    nsString extra;
+    m_customColumnHandlers[i]->GetRowProperties(index, extra);
+    if (!extra.IsEmpty())
+    {
+      properties.Append(' ');
+      properties.Append(extra);
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetColumnProperties(nsITreeColumn* col, nsAString& properties)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetCellProperties(int32_t aRow, nsITreeColumn *col, nsAString& properties)
+{
+  if (!IsValidIndex(aRow))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  // this is where we tell the tree to apply styles to a particular row
+  // i.e. if the row is an unread message...
+
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  nsresult rv = NS_OK;
+
+  rv = GetMsgHdrForViewIndex(aRow, getter_AddRefs(msgHdr));
+
+  if (NS_FAILED(rv) || !msgHdr)
+  {
+    ClearHdrCache();
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  }
+
+  const char16_t* colID;
+  col->GetIdConst(&colID);
+  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);
+  if (colHandler != nullptr)
+    colHandler->GetCellProperties(aRow, col, properties);
+  else if (colID[0] == 'c') // correspondent
+  {
+    if (IsOutgoingMsg(msgHdr))
+      properties.AssignLiteral("outgoing");
+    else
+      properties.AssignLiteral("incoming");
+  }
+
+  if (!properties.IsEmpty())
+    properties.Append(' ');
+
+  properties.Append(mMessageType);
+
+  uint32_t flags;
+  msgHdr->GetFlags(&flags);
+
+  if (!(flags & nsMsgMessageFlags::Read))
+    properties.AppendLiteral(" unread");
+  else
+    properties.AppendLiteral(" read");
+
+  if (flags & nsMsgMessageFlags::Replied)
+    properties.AppendLiteral(" replied");
+
+  if (flags & nsMsgMessageFlags::Forwarded)
+    properties.AppendLiteral(" forwarded");
+
+  if (flags & nsMsgMessageFlags::New)
+    properties.AppendLiteral(" new");
+
+  if (m_flags[aRow] & nsMsgMessageFlags::Marked)
+    properties.AppendLiteral(" flagged");
+
+  // For threaded display add the ignoreSubthread property to the
+  // subthread top row (this row). For non-threaded add it to all rows.
+  if (!(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) &&
+      (flags & nsMsgMessageFlags::Ignored)) {
+    properties.AppendLiteral(" ignoreSubthread");
+  }
+  else {
+    bool ignored;
+    msgHdr->GetIsKilled(&ignored);
+    if (ignored)
+      properties.AppendLiteral(" ignoreSubthread");
+  }
+
+  nsCOMPtr <nsIMsgLocalMailFolder> localFolder = do_QueryInterface(m_folder);
+
+  if ((flags & nsMsgMessageFlags::Offline) || (localFolder && !(flags & nsMsgMessageFlags::Partial)))
+    properties.AppendLiteral(" offline");
+
+  if (flags & nsMsgMessageFlags::Attachment)
+    properties.AppendLiteral(" attach");
+
+  if ((mDeleteModel == nsMsgImapDeleteModels::IMAPDelete) && (flags & nsMsgMessageFlags::IMAPDeleted))
+    properties.AppendLiteral(" imapdeleted");
+
+  nsCString imageSize;
+  msgHdr->GetStringProperty("imageSize", getter_Copies(imageSize));
+  if (!imageSize.IsEmpty())
+    properties.AppendLiteral(" hasimage");
+
+  nsCString junkScoreStr;
+  msgHdr->GetStringProperty("junkscore", getter_Copies(junkScoreStr));
+  if (!junkScoreStr.IsEmpty()) {
+    if (junkScoreStr.ToInteger(&rv) == nsIJunkMailPlugin::IS_SPAM_SCORE)
+      properties.AppendLiteral(" junk");
+    else
+      properties.AppendLiteral(" notjunk");
+    NS_ASSERTION(NS_SUCCEEDED(rv), "Converting junkScore to integer failed.");
+  }
+
+  nsCString keywords;
+  FetchRowKeywords(aRow, msgHdr, keywords);
+  if (!keywords.IsEmpty())
+    AppendKeywordProperties(keywords, properties, true);
+
+  // this is a double fetch of the keywords property since we also fetch
+  // it for the tags - do we want to do this?
+  // I'm not sure anyone uses the kw- property, though it could be nice
+  // for people wanting to extend the thread pane.
+  nsCString keywordProperty;
+  msgHdr->GetStringProperty("keywords", getter_Copies(keywordProperty));
+  if (!keywordProperty.IsEmpty())
+  {
+    NS_ConvertUTF8toUTF16 keywords(keywordProperty);
+    int32_t spaceIndex = 0;
+    do
+    {
+      spaceIndex = keywords.FindChar(' ');
+      int32_t endOfKeyword = (spaceIndex == -1) ? keywords.Length() : spaceIndex;
+      properties.AppendLiteral(" kw-");
+      properties.Append(StringHead(keywords, endOfKeyword));
+      if (spaceIndex > 0)
+        keywords.Cut(0, endOfKeyword + 1);
+    }
+    while (spaceIndex > 0);
+  }
+
+#ifdef SUPPORT_PRIORITY_COLORS
+  // add special styles for priority
+  nsMsgPriorityValue priority;
+  msgHdr->GetPriority(&priority);
+  switch (priority)
+  {
+  case nsMsgPriority::highest:
+    properties.append(" priority-highest");
+    break;
+  case nsMsgPriority::high:
+    properties.append(" priority-high");
+    break;
+  case nsMsgPriority::low:
+    properties.append(" priority-low");
+    break;
+  case nsMsgPriority::lowest:
+    properties.append(" priority-lowest");
+    break;
+  default:
+    break;
+  }
+#endif
+
+
+  nsCOMPtr <nsIMsgThread> thread;
+  rv = GetThreadContainingIndex(aRow, getter_AddRefs(thread));
+  if (NS_SUCCEEDED(rv) && thread)
+  {
+    uint32_t numUnreadChildren;
+    thread->GetNumUnreadChildren(&numUnreadChildren);
+    if (numUnreadChildren > 0)
+      properties.AppendLiteral(" hasUnread");
+
+    // For threaded display add the ignore/watch properties to the
+    // thread top row. For non-threaded add it to all rows.
+    if (!(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) ||
+         ((m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) &&
+        (m_flags[aRow] & MSG_VIEW_FLAG_ISTHREAD))) {
+      thread->GetFlags(&flags);
+      if (flags & nsMsgMessageFlags::Watched)
+        properties.AppendLiteral(" watch");
+      if (flags & nsMsgMessageFlags::Ignored)
+        properties.AppendLiteral(" ignore");
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::IsContainer(int32_t index, bool *_retval)
+{
+  if (!IsValidIndex(index))
+      return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+  {
+    uint32_t flags = m_flags[index];
+    *_retval = !!(flags & MSG_VIEW_FLAG_HASCHILDREN);
+  }
+  else
+    *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::IsContainerOpen(int32_t index, bool *_retval)
+{
+  if (!IsValidIndex(index))
+      return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+  {
+    uint32_t flags = m_flags[index];
+    *_retval = (flags & MSG_VIEW_FLAG_HASCHILDREN) && !(flags & nsMsgMessageFlags::Elided);
+  }
+  else
+    *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::IsContainerEmpty(int32_t index, bool *_retval)
+{
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+  {
+    uint32_t flags = m_flags[index];
+    *_retval = !(flags & MSG_VIEW_FLAG_HASCHILDREN);
+  }
+  else
+    *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::IsSeparator(int32_t index, bool *_retval)
+{
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  *_retval = false;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetParentIndex(int32_t rowIndex, int32_t *_retval)
+{
+  *_retval = -1;
+
+  int32_t rowIndexLevel;
+  nsresult rv = GetLevel(rowIndex, &rowIndexLevel);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  int32_t i;
+  for(i = rowIndex; i >= 0; i--)
+  {
+    int32_t l;
+    GetLevel(i, &l);
+    if (l < rowIndexLevel)
+    {
+      *_retval = i;
+      break;
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::HasNextSibling(int32_t rowIndex, int32_t afterIndex, bool *_retval)
+{
+  *_retval = false;
+
+  int32_t rowIndexLevel;
+  GetLevel(rowIndex, &rowIndexLevel);
+
+  int32_t i;
+  int32_t count;
+  GetRowCount(&count);
+  for(i = afterIndex + 1; i < count; i++)
+  {
+    int32_t l;
+    GetLevel(i, &l);
+    if (l < rowIndexLevel)
+      break;
+    if (l == rowIndexLevel)
+    {
+      *_retval = true;
+      break;
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetLevel(int32_t index, int32_t *_retval)
+{
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+    *_retval = m_levels[index];
+  else
+    *_retval = 0;
+  return NS_OK;
+}
+
+// search view will override this since headers can span db's
+nsresult nsMsgDBView::GetMsgHdrForViewIndex(nsMsgViewIndex index, nsIMsgDBHdr **msgHdr)
+{
+  nsresult rv = NS_OK;
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  nsMsgKey key = m_keys[index];
+  if (key == nsMsgKey_None || !m_db)
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  if (key == m_cachedMsgKey)
+  {
+    *msgHdr = m_cachedHdr;
+    NS_IF_ADDREF(*msgHdr);
+  }
+  else
+  {
+    rv = m_db->GetMsgHdrForKey(key, msgHdr);
+    if (NS_SUCCEEDED(rv))
+    {
+      m_cachedHdr = *msgHdr;
+      m_cachedMsgKey = key;
+    }
+  }
+
+  return rv;
+}
+
+void nsMsgDBView::InsertMsgHdrAt(nsMsgViewIndex index, nsIMsgDBHdr *hdr,
+                                 nsMsgKey msgKey, uint32_t flags, uint32_t level)
+{
+  if ((int32_t) index < 0 || index > m_keys.Length())
+  {
+    // Something's gone wrong in a caller, but we have no clue why
+    // Return without adding the header to the view
+    NS_ERROR("Index for message header insertion out of array range!");
+    return;
+  }
+  m_keys.InsertElementAt(index, msgKey);
+  m_flags.InsertElementAt(index, flags);
+  m_levels.InsertElementAt(index, level);
+}
+
+void nsMsgDBView::SetMsgHdrAt(nsIMsgDBHdr *hdr, nsMsgViewIndex index,
+                              nsMsgKey msgKey, uint32_t flags, uint32_t level)
+{
+  m_keys[index] = msgKey;
+  m_flags[index] = flags;
+  m_levels[index] = level;
+}
+
+nsresult nsMsgDBView::GetFolderForViewIndex(nsMsgViewIndex index, nsIMsgFolder **aFolder)
+{
+  NS_IF_ADDREF(*aFolder = m_folder);
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::GetDBForViewIndex(nsMsgViewIndex index, nsIMsgDatabase **db)
+{
+  NS_IF_ADDREF(*db = m_db);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetImageSrc(int32_t aRow, nsITreeColumn* aCol, nsAString& aValue)
+{
+  NS_ENSURE_ARG_POINTER(aCol);
+  //attempt to retreive a custom column handler. If it exists call it and return
+  const char16_t* colID;
+  aCol->GetIdConst(&colID);
+
+  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);
+
+  if (colHandler)
+  {
+    colHandler->GetImageSrc(aRow, aCol, aValue);
+    return NS_OK;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::GetProgressMode(int32_t aRow, nsITreeColumn* aCol, int32_t* _retval)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetCellValue(int32_t aRow, nsITreeColumn* aCol, nsAString& aValue)
+{
+  if (!IsValidIndex(aRow))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  nsresult rv = GetMsgHdrForViewIndex(aRow, getter_AddRefs(msgHdr));
+
+  if (NS_FAILED(rv) || !msgHdr)
+  {
+    ClearHdrCache();
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  }
+
+  const char16_t* colID;
+  aCol->GetIdConst(&colID);
+
+  uint32_t flags;
+  msgHdr->GetFlags(&flags);
+
+  aValue.Truncate();
+  // provide a string "value" for cells that do not normally have text.
+  // use empty string for the normal states "Read", "Not Starred", "No Attachment" and "Not Junk"
+  switch (colID[0])
+  {
+    case 'a': // attachment column
+      if (flags & nsMsgMessageFlags::Attachment) {
+        nsString tmp_str;
+        tmp_str.Adopt(GetString(u"messageHasAttachment"));
+        aValue.Assign(tmp_str);
+      }
+      break;
+    case 'f': // flagged (starred) column
+      if (flags & nsMsgMessageFlags::Marked) {
+        nsString tmp_str;
+        tmp_str.Adopt(GetString(u"messageHasFlag"));
+        aValue.Assign(tmp_str);
+      }
+      break;
+    case 'j': // junk column
+      if (JunkControlsEnabled(aRow))
+      {
+        nsCString junkScoreStr;
+        msgHdr->GetStringProperty("junkscore", getter_Copies(junkScoreStr));
+        // Only need to assing a real value for junk, it's empty already
+        // as it should be for non-junk.
+        if (!junkScoreStr.IsEmpty() &&
+            (junkScoreStr.ToInteger(&rv) == nsIJunkMailPlugin::IS_SPAM_SCORE))
+          aValue.AssignLiteral("messageJunk");
+
+        NS_ASSERTION(NS_SUCCEEDED(rv), "Converting junkScore to integer failed.");
+      }
+      break;
+    case 't':
+      if (colID[1] == 'h' && (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay))
+      {       // thread column
+        bool isContainer, isContainerEmpty, isContainerOpen;
+        IsContainer(aRow, &isContainer);
+        if (isContainer)
+        {
+          IsContainerEmpty(aRow, &isContainerEmpty);
+          if (!isContainerEmpty)
+          {
+            nsString tmp_str;
+
+            IsContainerOpen(aRow, &isContainerOpen);
+            tmp_str.Adopt(GetString(isContainerOpen ?
+                            u"messageExpanded" :
+                            u"messageCollapsed"));
+            aValue.Assign(tmp_str);
+          }
+        }
+      }
+      break;
+    case 'u': // read/unread column
+      if (!(flags & nsMsgMessageFlags::Read)) {
+        nsString tmp_str;
+        tmp_str.Adopt(GetString(u"messageUnread"));
+        aValue.Assign(tmp_str);
+      }
+      break;
+    default:
+      aValue.Assign(colID);
+      break;
+  }
+  return rv;
+}
+
+void nsMsgDBView::RememberDeletedMsgHdr(nsIMsgDBHdr *msgHdr)
+{
+  nsCString messageId;
+  msgHdr->GetMessageId(getter_Copies(messageId));
+  if (mRecentlyDeletedArrayIndex >= mRecentlyDeletedMsgIds.Length())
+    mRecentlyDeletedMsgIds.AppendElement(messageId);
+  else
+    mRecentlyDeletedMsgIds[mRecentlyDeletedArrayIndex] = messageId;
+  // only remember last 20 deleted msgs.
+  mRecentlyDeletedArrayIndex = (mRecentlyDeletedArrayIndex + 1) % 20;
+}
+
+bool nsMsgDBView::WasHdrRecentlyDeleted(nsIMsgDBHdr *msgHdr)
+{
+  nsCString messageId;
+  msgHdr->GetMessageId(getter_Copies(messageId));
+  return mRecentlyDeletedMsgIds.Contains(messageId);
+}
+
+//add a custom column handler
+NS_IMETHODIMP nsMsgDBView::AddColumnHandler(const nsAString& column, nsIMsgCustomColumnHandler* handler)
+{
+  bool custColInSort = false;
+  size_t index = m_customColumnHandlerIDs.IndexOf(column);
+
+  nsAutoString strColID(column);
+
+  //does not exist
+  if (index == m_customColumnHandlerIDs.NoIndex)
+  {
+    m_customColumnHandlerIDs.AppendElement(strColID);
+    m_customColumnHandlers.AppendObject(handler);
+  }
+  else
+  {
+    //insert new handler into the appropriate place in the COMPtr array
+    //no need to replace the column ID (it's the same)
+    m_customColumnHandlers.ReplaceObjectAt(handler, index);
+
+  }
+  // Check if the column name matches any of the columns in
+  // m_sortColumns, and if so, set m_sortColumns[i].mColHandler
+  for (uint32_t i = 0; i < m_sortColumns.Length(); i++)
+  {
+    MsgViewSortColumnInfo &sortInfo = m_sortColumns[i];
+    if (sortInfo.mSortType == nsMsgViewSortType::byCustom &&
+        sortInfo.mCustomColumnName.Equals(column))
+    {
+      custColInSort = true;
+      sortInfo.mColHandler = handler;
+    }
+  }
+
+  if (m_viewFlags & nsMsgViewFlagsType::kGroupBySort)
+    // Grouped view has its own ways.
+    return NS_OK;
+
+  // This cust col is in sort columns, and all are now registered, so sort.
+  if (custColInSort && !CustomColumnsInSortAndNotRegistered())
+    Sort(m_sortType, m_sortOrder);
+
+  return NS_OK;
+}
+
+//remove a custom column handler
+NS_IMETHODIMP nsMsgDBView::RemoveColumnHandler(const nsAString& aColID)
+{
+
+  // here we should check if the column name matches any of the columns in
+  // m_sortColumns, and if so, clear m_sortColumns[i].mColHandler
+  size_t index = m_customColumnHandlerIDs.IndexOf(aColID);
+
+  if (index != m_customColumnHandlerIDs.NoIndex)
+  {
+    m_customColumnHandlerIDs.RemoveElementAt(index);
+    m_customColumnHandlers.RemoveObjectAt(index);
+    // Check if the column name matches any of the columns in
+    // m_sortColumns, and if so, clear m_sortColumns[i].mColHandler
+    for (uint32_t i = 0; i < m_sortColumns.Length(); i++)
+    {
+      MsgViewSortColumnInfo &sortInfo = m_sortColumns[i];
+      if (sortInfo.mSortType == nsMsgViewSortType::byCustom &&
+            sortInfo.mCustomColumnName.Equals(aColID))
+        sortInfo.mColHandler = nullptr;
+    }
+
+    return NS_OK;
+  }
+
+  return NS_ERROR_FAILURE; //can't remove a column that isn't currently custom handled
+}
+
+//TODO: NS_ENSURE_SUCCESS
+nsIMsgCustomColumnHandler* nsMsgDBView::GetCurColumnHandler()
+{
+  return GetColumnHandler(m_curCustomColumn.get());
+}
+
+NS_IMETHODIMP nsMsgDBView::SetCurCustomColumn(const nsAString& aColID)
+{
+  m_curCustomColumn = aColID;
+
+  if (m_viewFolder)
+  {
+    nsCOMPtr <nsIMsgDatabase> db;
+    nsCOMPtr <nsIDBFolderInfo> folderInfo;
+    nsresult rv = m_viewFolder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo), getter_AddRefs(db));
+    NS_ENSURE_SUCCESS(rv,rv);
+    folderInfo->SetProperty("customSortCol", aColID);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetCurCustomColumn(nsAString &result)
+{
+  result = m_curCustomColumn;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSecondaryCustomColumn(nsAString &result)
+{
+  result = m_secondaryCustomColumn;
+  return NS_OK;
+}
+
+nsIMsgCustomColumnHandler* nsMsgDBView::GetColumnHandler(const char16_t *colID)
+{
+  size_t index = m_customColumnHandlerIDs.IndexOf(nsDependentString(colID));
+  return (index != m_customColumnHandlerIDs.NoIndex) ?
+    m_customColumnHandlers[index] : nullptr;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetColumnHandler(const nsAString& aColID, nsIMsgCustomColumnHandler** aHandler)
+{
+  NS_ENSURE_ARG_POINTER(aHandler);
+  nsAutoString column(aColID);
+  NS_IF_ADDREF(*aHandler = GetColumnHandler(column.get()));
+  return (*aHandler) ? NS_OK : NS_ERROR_FAILURE;
+}
+
+// Check if any active sort columns are custom. If none are custom, return false
+// and go on as always. If any are custom, and all are not registered yet,
+// return true (so that the caller can postpone sort). When the custom column
+// observer is notified with MsgCreateDBView and registers the handler,
+// AddColumnHandler will sort once all required handlers are set.
+bool nsMsgDBView::CustomColumnsInSortAndNotRegistered()
+{
+  // The initial sort on view open has been started, subsequent user initiated
+  // sort callers can ignore verifying cust col registration.
+  m_checkedCustomColumns = true;
+
+  // DecodeColumnSort must have already created m_sortColumns, otherwise we
+  // can't know, but go on anyway.
+  if (!m_sortColumns.Length())
+    return false;
+
+  bool custColNotRegistered = false;
+  for (uint32_t i = 0; i < m_sortColumns.Length() && !custColNotRegistered; i++)
+  {
+    if (m_sortColumns[i].mSortType == nsMsgViewSortType::byCustom &&
+        m_sortColumns[i].mColHandler == nullptr)
+      custColNotRegistered = true;
+  }
+
+  return custColNotRegistered;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetCellText(int32_t aRow, nsITreeColumn* aCol, nsAString& aValue)
+{
+  const char16_t* colID;
+  aCol->GetIdConst(&colID);
+
+  if (!IsValidIndex(aRow))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  aValue.Truncate();
+
+  //attempt to retreive a custom column handler. If it exists call it and return
+  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);
+
+  if (colHandler)
+  {
+    colHandler->GetCellText(aRow, aCol, aValue);
+    return NS_OK;
+  }
+
+  return CellTextForColumn(aRow, colID, aValue);
+}
+
+NS_IMETHODIMP nsMsgDBView::CellTextForColumn(int32_t aRow,
+                                             const char16_t *aColumnName,
+                                             nsAString &aValue)
+{
+  nsCOMPtr<nsIMsgDBHdr> msgHdr;
+  nsresult rv = GetMsgHdrForViewIndex(aRow, getter_AddRefs(msgHdr));
+
+  if (NS_FAILED(rv) || !msgHdr)
+  {
+    ClearHdrCache();
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  }
+
+  nsCOMPtr<nsIMsgThread> thread;
+
+  switch (aColumnName[0])
+  {
+  case 's':
+    if (aColumnName[1] == 'u') // subject
+      rv = FetchSubject(msgHdr, m_flags[aRow], aValue);
+    else if (aColumnName[1] == 'e') // sender
+      rv = FetchAuthor(msgHdr, aValue);
+    else if (aColumnName[1] == 'i') // size
+      rv = FetchSize(msgHdr, aValue);
+    else if (aColumnName[1] == 't') // status
+    {
+      uint32_t flags;
+      msgHdr->GetFlags(&flags);
+      rv = FetchStatus(flags, aValue);
+    }
+    break;
+  case 'r':
+    if (aColumnName[3] == 'i') // recipient
+      rv = FetchRecipients(msgHdr, aValue);
+    else if (aColumnName[3] == 'e') // received
+      rv = FetchDate(msgHdr, aValue, true);
+    break;
+  case 'd':  // date
+    rv = FetchDate(msgHdr, aValue);
+    break;
+  case 'c': // correspondent
+    if (IsOutgoingMsg(msgHdr))
+      rv = FetchRecipients(msgHdr, aValue);
+    else
+      rv = FetchAuthor(msgHdr, aValue);
+    break;
+  case 'p': // priority
+    rv = FetchPriority(msgHdr, aValue);
+    break;
+  case 'a': // account
+    if (aColumnName[1] == 'c') // account
+      rv = FetchAccount(msgHdr, aValue);
+    break;
+  case 't':
+    // total msgs in thread column
+    if (aColumnName[1] == 'o' && (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay))
+    {
+      if (m_flags[aRow] & MSG_VIEW_FLAG_ISTHREAD)
+      {
+        rv = GetThreadContainingIndex(aRow, getter_AddRefs(thread));
+        if (NS_SUCCEEDED(rv) && thread)
+        {
+          nsAutoString formattedCountString;
+          uint32_t numChildren;
+          thread->GetNumChildren(&numChildren);
+          formattedCountString.AppendInt(numChildren);
+          aValue.Assign(formattedCountString);
+        }
+      }
+    }
+    else if (aColumnName[1] == 'a') // tags
+    {
+      rv = FetchTags(msgHdr, aValue);
+    }
+    break;
+  case 'u':
+    // unread msgs in thread col
+    if (aColumnName[6] == 'C' && (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay))
+    {
+      if (m_flags[aRow] & MSG_VIEW_FLAG_ISTHREAD)
+      {
+        rv = GetThreadContainingIndex(aRow, getter_AddRefs(thread));
+        if (NS_SUCCEEDED(rv) && thread)
+        {
+          nsAutoString formattedCountString;
+          uint32_t numUnreadChildren;
+          thread->GetNumUnreadChildren(&numUnreadChildren);
+          if (numUnreadChildren > 0)
+          {
+            formattedCountString.AppendInt(numUnreadChildren);
+            aValue.Assign(formattedCountString);
+          }
+        }
+      }
+    }
+    break;
+  case 'j':
+    {
+      nsCString junkScoreStr;
+      msgHdr->GetStringProperty("junkscore", getter_Copies(junkScoreStr));
+      CopyASCIItoUTF16(junkScoreStr, aValue);
+    }
+    break;
+  case 'i': // id
+    {
+      nsAutoString keyString;
+      nsMsgKey key;
+      msgHdr->GetMessageKey(&key);
+      keyString.AppendInt((int64_t)key);
+      aValue.Assign(keyString);
+    }
+    break;
+  default:
+    break;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetTree(nsITreeBoxObject *tree)
+{
+  mTree = tree;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::ToggleOpenState(int32_t index)
+{
+  uint32_t numChanged;
+  nsresult rv = ToggleExpansion(index, &numChanged);
+  NS_ENSURE_SUCCESS(rv,rv);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::CycleHeader(nsITreeColumn* aCol)
+{
+    // let HandleColumnClick() in threadPane.js handle it
+    // since it will set / clear the sort indicators.
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::CycleCell(int32_t row, nsITreeColumn* col)
+{
+  if (!IsValidIndex(row))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  const char16_t* colID;
+  col->GetIdConst(&colID);
+
+  //attempt to retreive a custom column handler. If it exists call it and return
+  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);
+
+  if (colHandler)
+  {
+    colHandler->CycleCell(row, col);
+    return NS_OK;
+  }
+
+  // The cyclers below don't work for the grouped header dummy row, currently.
+  // A future implementation should consider both collapsed and expanded state.
+  if (m_viewFlags & nsMsgViewFlagsType::kGroupBySort &&
+      m_flags[row] & MSG_VIEW_FLAG_DUMMY)
+    return NS_OK;
+
+  switch (colID[0])
+  {
+  case 'u': // unreadButtonColHeader
+    if (colID[6] == 'B')
+      ApplyCommandToIndices(nsMsgViewCommandType::toggleMessageRead, (nsMsgViewIndex *) &row, 1);
+   break;
+  case 't': // tag cell, threaded cell or total cell
+    if (colID[1] == 'h')
+    {
+      ExpandAndSelectThreadByIndex(row, false);
+    }
+    else if (colID[1] == 'a')
+    {
+      // ### Do we want to keep this behaviour but switch it to tags?
+      // We could enumerate over the tags and go to the next one - it looks
+      // to me like this wasn't working before tags landed, so maybe not
+      // worth bothering with.
+    }
+    break;
+  case 'f': // flagged column
+    // toggle the flagged status of the element at row.
+    if (m_flags[row] & nsMsgMessageFlags::Marked)
+      ApplyCommandToIndices(nsMsgViewCommandType::unflagMessages, (nsMsgViewIndex *) &row, 1);
+    else
+      ApplyCommandToIndices(nsMsgViewCommandType::flagMessages, (nsMsgViewIndex *) &row, 1);
+    break;
+  case 'j': // junkStatus column
+    {
+      if (!JunkControlsEnabled(row))
+        return NS_OK;
+
+      nsCOMPtr <nsIMsgDBHdr> msgHdr;
+
+      nsresult rv = GetMsgHdrForViewIndex(row, getter_AddRefs(msgHdr));
+      if (NS_SUCCEEDED(rv) && msgHdr)
+      {
+        nsCString junkScoreStr;
+        rv = msgHdr->GetStringProperty("junkscore", getter_Copies(junkScoreStr));
+        if (junkScoreStr.IsEmpty() || (junkScoreStr.ToInteger(&rv) == nsIJunkMailPlugin::IS_HAM_SCORE))
+          ApplyCommandToIndices(nsMsgViewCommandType::junk, (nsMsgViewIndex *) &row, 1);
+        else
+          ApplyCommandToIndices(nsMsgViewCommandType::unjunk, (nsMsgViewIndex *) &row, 1);
+
+        NS_ASSERTION(NS_SUCCEEDED(rv), "Converting junkScore to integer failed.");
+      }
+    }
+    break;
+  default:
+    break;
+
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::PerformAction(const char16_t *action)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::PerformActionOnRow(const char16_t *action, int32_t row)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::PerformActionOnCell(const char16_t *action, int32_t row, nsITreeColumn* col)
+{
+  return NS_OK;
+}
+
+///////////////////////////////////////////////////////////////////////////
+// end nsITreeView Implementation Methods
+///////////////////////////////////////////////////////////////////////////
+
+NS_IMETHODIMP nsMsgDBView::Open(nsIMsgFolder *folder, nsMsgViewSortTypeValue sortType, nsMsgViewSortOrderValue sortOrder, nsMsgViewFlagsTypeValue viewFlags, int32_t *pCount)
+{
+  m_viewFlags = viewFlags;
+  m_sortOrder = sortOrder;
+  m_sortType = sortType;
+
+  nsresult rv;
+  nsCOMPtr<nsIMsgAccountManager> accountManager =
+           do_GetService(NS_MSGACCOUNTMANAGER_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  bool userNeedsToAuthenticate = false;
+  // if we're PasswordProtectLocalCache, then we need to find out if the server is authenticated.
+  (void) accountManager->GetUserNeedsToAuthenticate(&userNeedsToAuthenticate);
+  if (userNeedsToAuthenticate)
+    return NS_MSG_USER_NOT_AUTHENTICATED;
+
+  if (folder) // search view will have a null folder
+  {
+    nsCOMPtr <nsIDBFolderInfo> folderInfo;
+    rv = folder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo), getter_AddRefs(m_db));
+    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsIMsgDBService> msgDBService = do_GetService(NS_MSGDB_SERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    msgDBService->RegisterPendingListener(folder, this);
+    m_folder = folder;
+
+    if (!m_viewFolder)
+      // There is never a viewFolder already set except for the single folder
+      // saved search case, where the backing folder m_folder is different from
+      // the m_viewFolder with its own dbFolderInfo state.
+      m_viewFolder = folder;
+
+    SetMRUTimeForFolder(m_viewFolder);
+
+    RestoreSortInfo();
+
+    // determine if we are in a news folder or not.
+    // if yes, we'll show lines instead of size, and special icons in the thread pane
+    nsCOMPtr <nsIMsgIncomingServer> server;
+    rv = folder->GetServer(getter_AddRefs(server));
+    NS_ENSURE_SUCCESS(rv,rv);
+    nsCString type;
+    rv = server->GetType(type);
+    NS_ENSURE_SUCCESS(rv,rv);
+
+    // I'm not sure this is correct, because XF virtual folders with mixed news
+    // and mail can have this set.
+    mIsNews = MsgLowerCaseEqualsLiteral(type, "nntp");
+
+    // Default to a virtual folder if folder not set, since synthetic search
+    // views may not have a folder.
+    uint32_t folderFlags = nsMsgFolderFlags::Virtual;
+    if (folder)
+      folder->GetFlags(&folderFlags);
+    mIsXFVirtual = folderFlags & nsMsgFolderFlags::Virtual;
+
+    if (!mIsXFVirtual && MsgLowerCaseEqualsLiteral(type, "rss"))
+      mIsRss = true;
+
+    // special case nntp --> news since we'll break themes if we try to be consistent
+    if (mIsNews)
+      mMessageType.AssignLiteral("news");
+    else
+      CopyUTF8toUTF16(type, mMessageType);
+
+    GetImapDeleteModel(nullptr);
+
+    nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
+    if (prefs)
+    {
+      prefs->GetBoolPref("mailnews.sort_threads_by_root", &mSortThreadsByRoot);
+
+      if (mIsNews)
+        prefs->GetBoolPref("news.show_size_in_lines", &mShowSizeInLines);
+    }
+  }
+
+  nsCOMPtr<nsIArray> identities;
+  rv = accountManager->GetAllIdentities(getter_AddRefs(identities));
+  if (!identities)
+    return rv;
+
+  uint32_t count;
+  identities->GetLength(&count);
+  for (uint32_t i = 0; i < count; i++)
+  {
+    nsCOMPtr<nsIMsgIdentity> identity(do_QueryElementAt(identities, i));
+    if (!identity)
+      continue;
+
+    nsCString email;
+    identity->GetEmail(email);
+    if (!email.IsEmpty())
+      mEmails.PutEntry(email);
+
+    identity->GetReplyTo(email);
+    if (!email.IsEmpty())
+      mEmails.PutEntry(email);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::Close()
+{
+  int32_t oldSize = GetSize();
+  // this is important, because the tree will ask us for our
+  // row count, which get determine from the number of keys.
+  m_keys.Clear();
+  // be consistent
+  m_flags.Clear();
+  m_levels.Clear();
+
+  // clear these out since they no longer apply if we're switching a folder
+  if (mJunkHdrs)
+    mJunkHdrs->Clear();
+
+  // this needs to happen after we remove all the keys, since RowCountChanged() will call our GetRowCount()
+  if (mTree)
+    mTree->RowCountChanged(0, -oldSize);
+
+  ClearHdrCache();
+  if (m_db)
+  {
+    m_db->RemoveListener(this);
+    m_db = nullptr;
+  }
+  if (m_folder)
+  {
+    nsresult rv;
+    nsCOMPtr<nsIMsgDBService> msgDBService = do_GetService(NS_MSGDB_SERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    msgDBService->UnregisterPendingListener(this);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::OpenWithHdrs(nsISimpleEnumerator *aHeaders, nsMsgViewSortTypeValue aSortType,
+                                        nsMsgViewSortOrderValue aSortOrder, nsMsgViewFlagsTypeValue aViewFlags,
+                                        int32_t *aCount)
+{
+  NS_ASSERTION(false, "not implemented");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP nsMsgDBView::Init(nsIMessenger * aMessengerInstance, nsIMsgWindow * aMsgWindow, nsIMsgDBViewCommandUpdater *aCmdUpdater)
+{
+  mMessengerWeak = do_GetWeakReference(aMessengerInstance);
+  mMsgWindowWeak = do_GetWeakReference(aMsgWindow);
+  mCommandUpdater = aCmdUpdater;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetSuppressCommandUpdating(bool aSuppressCommandUpdating)
+{
+  mSuppressCommandUpdating = aSuppressCommandUpdating;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSuppressCommandUpdating(bool * aSuppressCommandUpdating)
+{
+  *aSuppressCommandUpdating = mSuppressCommandUpdating;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetSuppressMsgDisplay(bool aSuppressDisplay)
+{
+  uint32_t numSelected = 0;
+  GetNumSelected(&numSelected);
+
+  bool forceDisplay = false;
+  if (mSuppressMsgDisplay && !aSuppressDisplay && numSelected == 1)
+    forceDisplay = true;
+
+  mSuppressMsgDisplay = aSuppressDisplay;
+  if (forceDisplay)
+  {
+    // get the view indexfor the currently selected message
+    nsMsgViewIndex viewIndex;
+    nsresult rv = GetViewIndexForFirstSelectedMsg(&viewIndex);
+    if (NS_SUCCEEDED(rv) && viewIndex != nsMsgViewIndex_None)
+       LoadMessageByViewIndex(viewIndex);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSuppressMsgDisplay(bool * aSuppressDisplay)
+{
+  *aSuppressDisplay = mSuppressMsgDisplay;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetUsingLines(bool * aUsingLines)
+{
+  *aUsingLines = mShowSizeInLines;
+  return NS_OK;
+}
+
+int CompareViewIndices (const void *v1, const void *v2, void *)
+{
+  nsMsgViewIndex i1 = *(nsMsgViewIndex*) v1;
+  nsMsgViewIndex i2 = *(nsMsgViewIndex*) v2;
+  return i1 - i2;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetIndicesForSelection(uint32_t *length, nsMsgViewIndex **indices)
+{
+  NS_ENSURE_ARG_POINTER(length);
+  *length = 0;
+  NS_ENSURE_ARG_POINTER(indices);
+  *indices = nullptr;
+
+  nsMsgViewIndexArray selection;
+  GetSelectedIndices(selection);
+  uint32_t numIndices = selection.Length();
+  if (!numIndices) return NS_OK;
+  *length = numIndices;
+
+  uint32_t datalen = numIndices * sizeof(nsMsgViewIndex);
+  *indices = (nsMsgViewIndex *)NS_Alloc(datalen);
+  if (!*indices) return NS_ERROR_OUT_OF_MEMORY;
+  memcpy(*indices, selection.Elements(), datalen);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSelectedMsgHdrs(uint32_t *aLength, nsIMsgDBHdr ***aResult)
+{
+  nsresult rv;
+
+  NS_ENSURE_ARG_POINTER(aLength);
+  *aLength = 0;
+
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = nullptr;
+
+  nsMsgViewIndexArray selection;
+  GetSelectedIndices(selection);
+  uint32_t numIndices = selection.Length();
+  if (!numIndices) return NS_OK;
+
+  nsCOMPtr<nsIMutableArray> messages(do_CreateInstance(NS_ARRAY_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = GetHeadersFromSelection(selection.Elements(), numIndices, messages);
+  NS_ENSURE_SUCCESS(rv, rv);
+  uint32_t numMsgsSelected;
+  messages->GetLength(&numMsgsSelected);
+
+  nsIMsgDBHdr **headers = static_cast<nsIMsgDBHdr**>(NS_Alloc(
+    sizeof(nsIMsgDBHdr*) * numMsgsSelected));
+  for (uint32_t i = 0; i < numMsgsSelected; i++)
+  {
+    nsCOMPtr<nsIMsgDBHdr> msgHdr = do_QueryElementAt(messages, i, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    msgHdr.forget(&headers[i]); // Already AddRefed
+  }
+
+  *aLength = numMsgsSelected;
+  *aResult = headers;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetMsgHdrsForSelection(nsIMutableArray **aResult)
+{
+  nsMsgViewIndexArray selection;
+  GetSelectedIndices(selection);
+  uint32_t numIndices = selection.Length();
+
+  nsresult rv;
+  nsCOMPtr<nsIMutableArray> messages(do_CreateInstance(NS_ARRAY_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = GetHeadersFromSelection(selection.Elements(), numIndices, messages);
+  NS_ENSURE_SUCCESS(rv, rv);
+  messages.forget(aResult);
+  return rv;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetURIsForSelection(uint32_t *length, char ***uris)
+{
+  nsresult rv = NS_OK;
+
+  NS_ENSURE_ARG_POINTER(length);
+  *length = 0;
+
+  NS_ENSURE_ARG_POINTER(uris);
+  *uris = nullptr;
+
+  nsMsgViewIndexArray selection;
+  GetSelectedIndices(selection);
+  uint32_t numIndices = selection.Length();
+  if (!numIndices) return NS_OK;
+
+  nsCOMPtr<nsIMutableArray> messages(do_CreateInstance(NS_ARRAY_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = GetHeadersFromSelection(selection.Elements(), numIndices, messages);
+  NS_ENSURE_SUCCESS(rv, rv);
+  messages->GetLength(length);
+  uint32_t numMsgsSelected = *length;
+
+  char **outArray, **next;
+  next = outArray = (char **)moz_xmalloc(numMsgsSelected * sizeof(char *));
+  if (!outArray) return NS_ERROR_OUT_OF_MEMORY;
+  for (uint32_t i = 0; i < numMsgsSelected; i++)
+  {
+    nsCString tmpUri;
+    nsCOMPtr<nsIMsgDBHdr> msgHdr = do_QueryElementAt(messages, i, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsIMsgFolder> folder;
+    nsMsgKey msgKey;
+    msgHdr->GetMessageKey(&msgKey);
+    msgHdr->GetFolder(getter_AddRefs(folder));
+    rv = GenerateURIForMsgKey(msgKey, folder, tmpUri);
+    NS_ENSURE_SUCCESS(rv,rv);
+    *next = ToNewCString(tmpUri);
+    if (!*next)
+      return NS_ERROR_OUT_OF_MEMORY;
+
+    next++;
+  }
+
+  *uris = outArray;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetURIForViewIndex(nsMsgViewIndex index, nsACString &result)
+{
+  nsresult rv;
+  nsCOMPtr <nsIMsgFolder> folder = m_folder;
+  if (!folder)
+  {
+    rv = GetFolderForViewIndex(index, getter_AddRefs(folder));
+    NS_ENSURE_SUCCESS(rv,rv);
+  }
+  if (index == nsMsgViewIndex_None || index >= m_flags.Length() ||
+      m_flags[index] & MSG_VIEW_FLAG_DUMMY)
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  return GenerateURIForMsgKey(m_keys[index], folder, result);
+}
+
+NS_IMETHODIMP nsMsgDBView::DoCommandWithFolder(nsMsgViewCommandTypeValue command, nsIMsgFolder *destFolder)
+{
+  NS_ENSURE_ARG_POINTER(destFolder);
+
+  nsMsgViewIndexArray selection;
+
+  GetSelectedIndices(selection);
+
+  nsMsgViewIndex *indices = selection.Elements();
+  int32_t numIndices = selection.Length();
+
+  nsresult rv = NS_OK;
+  switch (command) {
+    case nsMsgViewCommandType::copyMessages:
+    case nsMsgViewCommandType::moveMessages:
+        NoteStartChange(nsMsgViewNotificationCode::none, 0, 0);
+        rv = ApplyCommandToIndicesWithFolder(command, indices, numIndices, destFolder);
+        NoteEndChange(nsMsgViewNotificationCode::none, 0, 0);
+        break;
+    default:
+        NS_ASSERTION(false, "invalid command type");
+        rv = NS_ERROR_UNEXPECTED;
+        break;
+  }
+  return rv;
+
+}
+
+NS_IMETHODIMP nsMsgDBView::DoCommand(nsMsgViewCommandTypeValue command)
+{
+  nsMsgViewIndexArray selection;
+
+  GetSelectedIndices(selection);
+
+  nsMsgViewIndex *indices = selection.Elements();
+  int32_t numIndices = selection.Length();
+  nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
+
+  nsresult rv = NS_OK;
+  switch (command)
+  {
+  case nsMsgViewCommandType::downloadSelectedForOffline:
+    return DownloadForOffline(msgWindow, indices, numIndices);
+  case nsMsgViewCommandType::downloadFlaggedForOffline:
+    return DownloadFlaggedForOffline(msgWindow);
+  case nsMsgViewCommandType::markMessagesRead:
+  case nsMsgViewCommandType::markMessagesUnread:
+  case nsMsgViewCommandType::toggleMessageRead:
+  case nsMsgViewCommandType::flagMessages:
+  case nsMsgViewCommandType::unflagMessages:
+  case nsMsgViewCommandType::deleteMsg:
+  case nsMsgViewCommandType::undeleteMsg:
+  case nsMsgViewCommandType::deleteNoTrash:
+  case nsMsgViewCommandType::markThreadRead:
+  case nsMsgViewCommandType::junk:
+  case nsMsgViewCommandType::unjunk:
+    NoteStartChange(nsMsgViewNotificationCode::none, 0, 0);
+    rv = ApplyCommandToIndices(command, indices, numIndices);
+    NoteEndChange(nsMsgViewNotificationCode::none, 0, 0);
+    break;
+  case nsMsgViewCommandType::selectAll:
+    if (mTreeSelection)
+    {
+      // if in threaded mode, we need to expand all before selecting
+      if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+          rv = ExpandAll();
+      mTreeSelection->SelectAll();
+      if (mTree)
+        mTree->Invalidate();
+    }
+    break;
+  case nsMsgViewCommandType::selectThread:
+    rv = ExpandAndSelectThread();
+    break;
+  case nsMsgViewCommandType::selectFlagged:
+    if (!mTreeSelection)
+      rv = NS_ERROR_UNEXPECTED;
+    else
+    {
+      mTreeSelection->SetSelectEventsSuppressed(true);
+      mTreeSelection->ClearSelection();
+      // XXX ExpandAll?
+      nsMsgViewIndex numIndices = GetSize();
+      for (nsMsgViewIndex curIndex = 0; curIndex < numIndices; curIndex++)
+      {
+        if (m_flags[curIndex] & nsMsgMessageFlags::Marked)
+          mTreeSelection->ToggleSelect(curIndex);
+      }
+      mTreeSelection->SetSelectEventsSuppressed(false);
+    }
+    break;
+  case nsMsgViewCommandType::markAllRead:
+    if (m_folder)
+    {
+      SetSuppressChangeNotifications(true);
+      rv = m_folder->MarkAllMessagesRead(msgWindow);
+      SetSuppressChangeNotifications(false);
+      if (mTree)
+        mTree->Invalidate();
+    }
+    break;
+  case nsMsgViewCommandType::toggleThreadWatched:
+    rv = ToggleWatched(indices,  numIndices);
+    break;
+  case nsMsgViewCommandType::expandAll:
+    rv = ExpandAll();
+    m_viewFlags |= nsMsgViewFlagsType::kExpandAll;
+    SetViewFlags(m_viewFlags);
+    if (mTree)
+      mTree->Invalidate();
+    break;
+  case nsMsgViewCommandType::collapseAll:
+    rv = CollapseAll();
+    m_viewFlags &= ~nsMsgViewFlagsType::kExpandAll;
+    SetViewFlags(m_viewFlags);
+    if(mTree)
+      mTree->Invalidate();
+    break;
+  default:
+    NS_ASSERTION(false, "invalid command type");
+    rv = NS_ERROR_UNEXPECTED;
+    break;
+  }
+  return rv;
+}
+
+bool nsMsgDBView::ServerSupportsFilterAfterTheFact()
+{
+  if (!m_folder)  // cross folder virtual folders might not have a folder set.
+    return false;
+
+  nsCOMPtr <nsIMsgIncomingServer> server;
+  nsresult rv = m_folder->GetServer(getter_AddRefs(server));
+  if (NS_FAILED(rv))
+    return false; // unexpected
+
+  // filter after the fact is implement using search
+  // so if you can't search, you can't filter after the fact
+  bool canSearch;
+  rv = server->GetCanSearchMessages(&canSearch);
+  if (NS_FAILED(rv))
+    return false; // unexpected
+
+  return canSearch;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetCommandStatus(nsMsgViewCommandTypeValue command, bool *selectable_p, nsMsgViewCommandCheckStateValue *selected_p)
+{
+  nsresult rv = NS_OK;
+
+  bool haveSelection;
+  int32_t rangeCount;
+  nsMsgViewIndexArray selection;
+  GetSelectedIndices(selection);
+  int32_t numIndices = selection.Length();
+  nsMsgViewIndex *indices = selection.Elements();
+  // if range count is non-zero, we have at least one item selected, so we have a selection
+  if (mTreeSelection && NS_SUCCEEDED(mTreeSelection->GetRangeCount(&rangeCount)) && rangeCount > 0)
+    haveSelection = NonDummyMsgSelected(indices, numIndices);
+  else
+  // If we don't have a tree selection we must be in stand alone mode.
+    haveSelection = IsValidIndex(m_currentlyDisplayedViewIndex);
+
+  switch (command)
+  {
+  case nsMsgViewCommandType::deleteMsg:
+  case nsMsgViewCommandType::deleteNoTrash:
+    {
+      bool canDelete;
+      if (m_folder && NS_SUCCEEDED(m_folder->GetCanDeleteMessages(&canDelete)) && !canDelete)
+        *selectable_p = false;
+      else
+        *selectable_p = haveSelection;
+    }
+    break;
+  case nsMsgViewCommandType::applyFilters:
+    // disable if no messages
+    // XXX todo, check that we have filters, and at least one is enabled
+    *selectable_p = GetSize();
+    if (*selectable_p)
+      *selectable_p = ServerSupportsFilterAfterTheFact();
+    break;
+  case nsMsgViewCommandType::runJunkControls:
+    // disable if no messages
+    // XXX todo, check that we have JMC enabled?
+    *selectable_p = GetSize() && JunkControlsEnabled(nsMsgViewIndex_None);
+    break;
+  case nsMsgViewCommandType::deleteJunk:
+    {
+      // disable if no messages, or if we can't delete (like news and certain imap folders)
+      bool canDelete;
+      *selectable_p = GetSize() && (m_folder && NS_SUCCEEDED(m_folder->GetCanDeleteMessages(&canDelete)) && canDelete);
+    }
+    break;
+  case nsMsgViewCommandType::markMessagesRead:
+  case nsMsgViewCommandType::markMessagesUnread:
+  case nsMsgViewCommandType::toggleMessageRead:
+  case nsMsgViewCommandType::flagMessages:
+  case nsMsgViewCommandType::unflagMessages:
+  case nsMsgViewCommandType::toggleThreadWatched:
+  case nsMsgViewCommandType::markThreadRead:
+  case nsMsgViewCommandType::downloadSelectedForOffline:
+    *selectable_p = haveSelection;
+    break;
+  case nsMsgViewCommandType::junk:
+  case nsMsgViewCommandType::unjunk:
+    *selectable_p = haveSelection && numIndices && JunkControlsEnabled(selection[0]);
+    break;
+  case nsMsgViewCommandType::cmdRequiringMsgBody:
+    *selectable_p = haveSelection && (!WeAreOffline() || OfflineMsgSelected(indices, numIndices));
+    break;
+  case nsMsgViewCommandType::downloadFlaggedForOffline:
+  case nsMsgViewCommandType::markAllRead:
+    *selectable_p = true;
+    break;
+  default:
+    NS_ASSERTION(false, "invalid command type");
+    rv = NS_ERROR_FAILURE;
+  }
+  return rv;
+}
+
+// This method needs to be overridden by the various view classes
+// that have different kinds of threads. For example, in a
+// threaded quick search db view, we'd only want to include children
+// of the thread that fit the view (IMO). And when we have threaded
+// cross folder views, we would include all the children of the
+// cross-folder thread.
+nsresult nsMsgDBView::ListCollapsedChildren(nsMsgViewIndex viewIndex,
+                                            nsIMutableArray *messageArray)
+{
+  nsCOMPtr<nsIMsgDBHdr> msgHdr;
+  nsCOMPtr<nsIMsgThread> thread;
+  GetMsgHdrForViewIndex(viewIndex, getter_AddRefs(msgHdr));
+  if (!msgHdr)
+  {
+    NS_ASSERTION(false, "couldn't find message to expand");
+    return NS_MSG_MESSAGE_NOT_FOUND;
+  }
+  nsresult rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(thread));
+  NS_ENSURE_SUCCESS(rv, rv);
+  uint32_t numChildren;
+  thread->GetNumChildren(&numChildren);
+  for (uint32_t i = 1; i < numChildren && NS_SUCCEEDED(rv); i++)
+  {
+    nsCOMPtr<nsIMsgDBHdr> msgHdr;
+    rv = thread->GetChildHdrAt(i, getter_AddRefs(msgHdr));
+    if (!msgHdr)
+      continue;
+    rv = messageArray->AppendElement(msgHdr, false);
+  }
+  return rv;
+}
+
+bool nsMsgDBView::OperateOnMsgsInCollapsedThreads()
+{
+  if (mTreeSelection)
+  {
+    nsCOMPtr<nsITreeBoxObject> selTree;
+    mTreeSelection->GetTree(getter_AddRefs(selTree));
+    // no tree means stand-alone message window
+    if (!selTree)
+      return false;
+  }
+
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIPrefBranch> prefBranch (do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, false);
+
+  bool includeCollapsedMsgs = false;
+  prefBranch->GetBoolPref("mail.operate_on_msgs_in_collapsed_threads", &includeCollapsedMsgs);
+  return includeCollapsedMsgs;
+}
+
+nsresult nsMsgDBView::GetHeadersFromSelection(uint32_t *indices,
+                                              uint32_t numIndices,
+                                              nsIMutableArray *messageArray)
+{
+  nsresult rv = NS_OK;
+
+  // Don't include collapsed messages if the front end failed to summarize
+  // the selection.
+  bool includeCollapsedMsgs = OperateOnMsgsInCollapsedThreads() &&
+                                !mSummarizeFailed;
+
+  for (uint32_t index = 0;
+       index < (nsMsgViewIndex) numIndices && NS_SUCCEEDED(rv); index++)
+  {
+    nsMsgViewIndex viewIndex = indices[index];
+    if (viewIndex == nsMsgViewIndex_None)
+      continue;
+    uint32_t viewIndexFlags = m_flags[viewIndex];
+    if (viewIndexFlags & MSG_VIEW_FLAG_DUMMY)
+    {
+      // if collapsed dummy header selected, list its children
+      if (includeCollapsedMsgs && viewIndexFlags & nsMsgMessageFlags::Elided &&
+          m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+        rv = ListCollapsedChildren(viewIndex, messageArray);
+      continue;
+    }
+    nsCOMPtr<nsIMsgDBHdr> msgHdr;
+    rv = GetMsgHdrForViewIndex(viewIndex, getter_AddRefs(msgHdr));
+    if (NS_SUCCEEDED(rv) && msgHdr)
+    {
+      rv = messageArray->AppendElement(msgHdr, false);
+      if (NS_SUCCEEDED(rv) && includeCollapsedMsgs &&
+          viewIndexFlags & nsMsgMessageFlags::Elided &&
+          viewIndexFlags & MSG_VIEW_FLAG_HASCHILDREN &&
+          m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+      {
+        rv = ListCollapsedChildren(viewIndex, messageArray);
+      }
+    }
+  }
+  return rv;
+}
+
+nsresult
+nsMsgDBView::CopyMessages(nsIMsgWindow *window, nsMsgViewIndex *indices, int32_t numIndices, bool isMove, nsIMsgFolder *destFolder)
+{
+  if (m_deletingRows)
+  {
+    NS_ASSERTION(false, "Last move did not complete");
+    return NS_OK;
+  }
+
+  nsresult rv;
+  NS_ENSURE_ARG_POINTER(destFolder);
+  nsCOMPtr<nsIMutableArray> messageArray(do_CreateInstance(NS_ARRAY_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = GetHeadersFromSelection(indices, numIndices, messageArray);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  m_deletingRows = isMove && mDeleteModel != nsMsgImapDeleteModels::IMAPDelete;
+  if (m_deletingRows)
+    mIndicesToNoteChange.AppendElements(indices, numIndices);
+
+  nsCOMPtr<nsIMsgCopyService> copyService = do_GetService(NS_MSGCOPYSERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return copyService->CopyMessages(m_folder /* source folder */, messageArray, destFolder, isMove, nullptr /* listener */, window, true /*allowUndo*/);
+}
+
+nsresult
+nsMsgDBView::ApplyCommandToIndicesWithFolder(nsMsgViewCommandTypeValue command, nsMsgViewIndex* indices,
+                    int32_t numIndices, nsIMsgFolder *destFolder)
+{
+  nsresult rv = NS_OK;
+  NS_ENSURE_ARG_POINTER(destFolder);
+
+  nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
+  switch (command) {
+    case nsMsgViewCommandType::copyMessages:
+        NS_ASSERTION(!(m_folder == destFolder), "The source folder and the destination folder are the same");
+        if (m_folder != destFolder)
+          rv = CopyMessages(msgWindow, indices, numIndices, false /* isMove */, destFolder);
+        break;
+    case nsMsgViewCommandType::moveMessages:
+        NS_ASSERTION(!(m_folder == destFolder), "The source folder and the destination folder are the same");
+        if (m_folder != destFolder)
+          rv = CopyMessages(msgWindow, indices, numIndices, true     /* isMove */, destFolder);
+        break;
+    default:
+        NS_ASSERTION(false, "unhandled command");
+        rv = NS_ERROR_UNEXPECTED;
+        break;
+    }
+    return rv;
+}
+
+nsresult
+nsMsgDBView::ApplyCommandToIndices(nsMsgViewCommandTypeValue command, nsMsgViewIndex* indices,
+          int32_t numIndices)
+{
+  NS_ASSERTION(numIndices >= 0, "nsMsgDBView::ApplyCommandToIndices(): "
+               "numIndices is negative!");
+
+  if (numIndices == 0)
+    return NS_OK; // return quietly, just in case
+
+  nsCOMPtr<nsIMsgFolder> folder;
+  nsresult rv = GetFolderForViewIndex(indices[0], getter_AddRefs(folder));
+  nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
+  if (command == nsMsgViewCommandType::deleteMsg)
+    return DeleteMessages(msgWindow, indices, numIndices, false);
+  if (command == nsMsgViewCommandType::deleteNoTrash)
+    return DeleteMessages(msgWindow, indices, numIndices, true);
+
+  nsTArray<nsMsgKey> imapUids;
+  nsCOMPtr <nsIMsgImapMailFolder> imapFolder = do_QueryInterface(folder);
+  bool thisIsImapFolder = (imapFolder != nullptr);
+  nsCOMPtr<nsIJunkMailPlugin> junkPlugin;
+
+  // if this is a junk command, get the junk plugin.
+  if (command == nsMsgViewCommandType::junk ||
+      command == nsMsgViewCommandType::unjunk)
+  {
+    // get the folder from the first item; we assume that
+    // all messages in the view are from the same folder (no
+    // more junk status column in the 'search messages' dialog
+    // like in earlier versions...)
+
+     nsCOMPtr<nsIMsgIncomingServer> server;
+     rv = folder->GetServer(getter_AddRefs(server));
+     NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIMsgFilterPlugin> filterPlugin;
+    rv = server->GetSpamFilterPlugin(getter_AddRefs(filterPlugin));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    junkPlugin = do_QueryInterface(filterPlugin, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (!mJunkHdrs)
+    {
+      mJunkHdrs = do_CreateInstance(NS_ARRAY_CONTRACTID, &rv);
+      NS_ENSURE_SUCCESS(rv,rv);
+    }
+  }
+
+  folder->EnableNotifications(nsIMsgFolder::allMessageCountNotifications, false, true /*dbBatching*/);
+
+  // no sense going through the code that handles messages in collasped threads
+  // for mark thread read.
+  if (command == nsMsgViewCommandType::markThreadRead)
+  {
+    for (int32_t index = 0; index < numIndices; index++)
+      SetThreadOfMsgReadByIndex(indices[index], imapUids, true);
+  }
+  else
+  {
+    // Turn the selection into an array of msg hdrs. This may include messages
+    // in collapsed threads
+    uint32_t length;
+    nsCOMPtr<nsIMutableArray> messages(do_CreateInstance(NS_ARRAY_CONTRACTID, &rv));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = GetHeadersFromSelection(indices, numIndices, messages);
+    NS_ENSURE_SUCCESS(rv, rv);
+    messages->GetLength(&length);
+
+    if (thisIsImapFolder)
+      imapUids.SetLength(length);
+
+    for (uint32_t i = 0; i < length; i++)
+    {
+      nsMsgKey msgKey;
+      nsCOMPtr<nsIMsgDBHdr> msgHdr = do_QueryElementAt(messages, i);
+      msgHdr->GetMessageKey(&msgKey);
+      if (thisIsImapFolder)
+        imapUids[i] = msgKey;
+
+      switch (command)
+      {
+      case nsMsgViewCommandType::junk:
+        mNumMessagesRemainingInBatch++;
+        mJunkHdrs->AppendElement(msgHdr, false);
+        rv = SetMsgHdrJunkStatus(junkPlugin.get(), msgHdr,
+                                 nsIJunkMailPlugin::JUNK);
+        break;
+      case nsMsgViewCommandType::unjunk:
+        mNumMessagesRemainingInBatch++;
+        mJunkHdrs->AppendElement(msgHdr, false);
+        rv = SetMsgHdrJunkStatus(junkPlugin.get(), msgHdr,
+                                 nsIJunkMailPlugin::GOOD);
+        break;
+      case nsMsgViewCommandType::toggleMessageRead:
+      case nsMsgViewCommandType::undeleteMsg:
+      case nsMsgViewCommandType::markMessagesRead:
+      case nsMsgViewCommandType::markMessagesUnread:
+      case nsMsgViewCommandType::unflagMessages:
+      case nsMsgViewCommandType::flagMessages:
+        break; // this is completely handled in the code below.
+      default:
+        NS_ERROR("unhandled command");
+        break;
+      }
+    }
+
+    switch (command)
+    {
+      case nsMsgViewCommandType::toggleMessageRead:
+      {
+        nsCOMPtr<nsIMsgDBHdr> msgHdr = do_QueryElementAt(messages, 0);
+        if (!msgHdr)
+          break;
+        uint32_t msgFlags;
+        msgHdr->GetFlags(&msgFlags);
+        folder->MarkMessagesRead(messages,
+                                 !(msgFlags & nsMsgMessageFlags::Read));
+      }
+        break;
+      case nsMsgViewCommandType::markMessagesRead:
+      case nsMsgViewCommandType::markMessagesUnread:
+        folder->MarkMessagesRead(messages,
+                                 command == nsMsgViewCommandType::markMessagesRead);
+        break;
+      case nsMsgViewCommandType::unflagMessages:
+      case nsMsgViewCommandType::flagMessages:
+        folder->MarkMessagesFlagged(messages,
+                                    command == nsMsgViewCommandType::flagMessages);
+        break;
+      default:
+        break;
+
+    }
+    // Provide junk-related batch notifications
+    if ((command == nsMsgViewCommandType::junk) ||
+        (command == nsMsgViewCommandType::unjunk)) {
+      nsCOMPtr<nsIMsgFolderNotificationService>
+        notifier(do_GetService(NS_MSGNOTIFICATIONSERVICE_CONTRACTID));
+      if (notifier)
+        notifier->NotifyItemEvent(messages,
+                                  NS_LITERAL_CSTRING("JunkStatusChanged"),
+                                  (command == nsMsgViewCommandType::junk) ?
+                                    kJunkMsgAtom : kNotJunkMsgAtom);
+    }
+  }
+
+  folder->EnableNotifications(nsIMsgFolder::allMessageCountNotifications, true, true /*dbBatching*/);
+
+  if (thisIsImapFolder)
+  {
+    imapMessageFlagsType flags = kNoImapMsgFlag;
+    bool addFlags = false;
+    nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
+    switch (command)
+    {
+    case nsMsgViewCommandType::markThreadRead:
+      flags |= kImapMsgSeenFlag;
+      addFlags = true;
+      break;
+    case nsMsgViewCommandType::undeleteMsg:
+      flags = kImapMsgDeletedFlag;
+      addFlags = false;
+      break;
+    case nsMsgViewCommandType::junk:
+        return imapFolder->StoreCustomKeywords(msgWindow,
+                    NS_LITERAL_CSTRING("Junk"),
+                    NS_LITERAL_CSTRING("NonJunk"),
+                    imapUids.Elements(), imapUids.Length(),
+                    nullptr);
+    case nsMsgViewCommandType::unjunk:
+      {
+        nsCOMPtr<nsIMsgDBHdr> msgHdr;
+        GetHdrForFirstSelectedMessage(getter_AddRefs(msgHdr));
+        uint32_t msgFlags = 0;
+        if (msgHdr)
+          msgHdr->GetFlags(&msgFlags);
+        if (msgFlags & nsMsgMessageFlags::IMAPDeleted)
+          imapFolder->StoreImapFlags(kImapMsgDeletedFlag, false,
+                                     imapUids.Elements(),
+                                     imapUids.Length(), nullptr);
+        return imapFolder->StoreCustomKeywords(msgWindow,
+                    NS_LITERAL_CSTRING("NonJunk"),
+                    NS_LITERAL_CSTRING("Junk"),
+                    imapUids.Elements(), imapUids.Length(),
+                    nullptr);
+      }
+
+    default:
+      break;
+    }
+
+    if (flags != kNoImapMsgFlag)  // can't get here without thisIsImapThreadPane == TRUE
+      imapFolder->StoreImapFlags(flags, addFlags, imapUids.Elements(), imapUids.Length(), nullptr);
+
+  }
+
+  return rv;
+}
+
+// view modifications methods by index
+
+// This method just removes the specified line from the view. It does
+// NOT delete it from the database.
+nsresult nsMsgDBView::RemoveByIndex(nsMsgViewIndex index)
+{
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  m_keys.RemoveElementAt(index);
+  m_flags.RemoveElementAt(index);
+  m_levels.RemoveElementAt(index);
+
+  // the call to NoteChange() has to happen after we remove the key
+  // as NoteChange() will call RowCountChanged() which will call our GetRowCount()
+  if (!m_deletingRows)
+    NoteChange(index, -1, nsMsgViewNotificationCode::insertOrDelete); // an example where view is not the listener - D&D messages
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::DeleteMessages(nsIMsgWindow *window, nsMsgViewIndex *indices, int32_t numIndices, bool deleteStorage)
+{
+  if (m_deletingRows)
+  {
+    NS_WARNING("Last delete did not complete");
+    return NS_OK;
+  }
+  nsresult rv;
+  nsCOMPtr<nsIMutableArray> messageArray(do_CreateInstance(NS_ARRAY_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = GetHeadersFromSelection(indices, numIndices, messageArray);
+  NS_ENSURE_SUCCESS(rv, rv);
+  uint32_t numMsgs;
+  messageArray->GetLength(&numMsgs);
+
+  const char *warnCollapsedPref = "mail.warn_on_collapsed_thread_operation";
+  const char *warnShiftDelPref = "mail.warn_on_shift_delete";
+  const char *warnNewsPref = "news.warn_on_delete";
+  const char *warnTrashDelPref = "mail.warn_on_delete_from_trash";
+  const char *activePref = nullptr;
+  nsString warningName;
+  nsCOMPtr<nsIPrefBranch> prefBranch(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool trashFolder = false;
+  rv = m_folder->GetFlag(nsMsgFolderFlags::Trash, &trashFolder);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (trashFolder)
+  {
+    bool pref = false;
+    prefBranch->GetBoolPref(warnTrashDelPref, &pref);
+    if (pref)
+    {
+      activePref = warnTrashDelPref;
+      warningName.AssignLiteral("confirmMsgDelete.deleteFromTrash.desc");
+    }
+  }
+
+  if (!activePref && (uint32_t(numIndices) != numMsgs))
+  {
+    bool pref = false;
+    prefBranch->GetBoolPref(warnCollapsedPref, &pref);
+    if (pref)
+    {
+      activePref = warnCollapsedPref;
+      warningName.AssignLiteral("confirmMsgDelete.collapsed.desc");
+    }
+  }
+
+  if (!activePref && deleteStorage && !trashFolder)
+  {
+    bool pref = false;
+    prefBranch->GetBoolPref(warnShiftDelPref, &pref);
+    if (pref)
+    {
+      activePref = warnShiftDelPref;
+      warningName.AssignLiteral("confirmMsgDelete.deleteNoTrash.desc");
+    }
+  }
+
+  if (!activePref && mIsNews)
+  {
+    bool pref = false;
+    prefBranch->GetBoolPref(warnNewsPref, &pref);
+    if (pref)
+    {
+      activePref = warnNewsPref;
+      warningName.AssignLiteral("confirmMsgDelete.deleteNoTrash.desc");
+    }
+  }
+
+  if (activePref)
+  {
+    nsCOMPtr<nsIPrompt> dialog;
+
+    nsCOMPtr<nsIWindowWatcher> wwatch(do_GetService(NS_WINDOWWATCHER_CONTRACTID, &rv));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = wwatch->GetNewPrompter(0, getter_AddRefs(dialog));
+    NS_ENSURE_SUCCESS(rv, rv);
+    bool dontAsk = false; // "Don't ask..." - unchecked by default.
+    int32_t buttonPressed = 0;
+
+    nsString dialogTitle;
+    nsString confirmString;
+    nsString checkboxText;
+    nsString buttonApplyNowText;
+    dialogTitle.Adopt(GetString(u"confirmMsgDelete.title"));
+    checkboxText.Adopt(GetString(u"confirmMsgDelete.dontAsk.label"));
+    buttonApplyNowText.Adopt(GetString(u"confirmMsgDelete.delete.label"));
+
+    confirmString.Adopt(GetString(warningName.get()));
+
+    const uint32_t buttonFlags =
+      (nsIPrompt::BUTTON_TITLE_IS_STRING * nsIPrompt::BUTTON_POS_0) +
+      (nsIPrompt::BUTTON_TITLE_CANCEL * nsIPrompt::BUTTON_POS_1);
+    rv = dialog->ConfirmEx(dialogTitle.get(), confirmString.get(), buttonFlags,
+                           buttonApplyNowText.get(), nullptr, nullptr,
+                           checkboxText.get(), &dontAsk, &buttonPressed);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (buttonPressed)
+      return NS_ERROR_FAILURE;
+    if (dontAsk)
+      prefBranch->SetBoolPref(activePref, false);
+  }
+
+  if (mDeleteModel != nsMsgImapDeleteModels::IMAPDelete)
+    m_deletingRows = true;
+
+  if (m_deletingRows)
+    mIndicesToNoteChange.AppendElements(indices, numIndices);
+
+  rv = m_folder->DeleteMessages(messageArray, window, deleteStorage, false, nullptr, true /*allow Undo*/ );
+  if (NS_FAILED(rv))
+    m_deletingRows = false;
+  return rv;
+}
+
+nsresult nsMsgDBView::DownloadForOffline(nsIMsgWindow *window, nsMsgViewIndex *indices, int32_t numIndices)
+{
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIMutableArray> messageArray(do_CreateInstance(NS_ARRAY_CONTRACTID));
+  for (nsMsgViewIndex index = 0; index < (nsMsgViewIndex) numIndices; index++)
+  {
+    nsMsgKey key = m_keys[indices[index]];
+    nsCOMPtr <nsIMsgDBHdr> msgHdr;
+    rv = m_db->GetMsgHdrForKey(key, getter_AddRefs(msgHdr));
+    NS_ENSURE_SUCCESS(rv,rv);
+    if (msgHdr)
+    {
+      uint32_t flags;
+      msgHdr->GetFlags(&flags);
+      if (!(flags & nsMsgMessageFlags::Offline))
+        messageArray->AppendElement(msgHdr, false);
+    }
+  }
+  m_folder->DownloadMessagesForOffline(messageArray, window);
+  return rv;
+}
+
+nsresult nsMsgDBView::DownloadFlaggedForOffline(nsIMsgWindow *window)
+{
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIMutableArray> messageArray(do_CreateInstance(NS_ARRAY_CONTRACTID));
+  nsCOMPtr <nsISimpleEnumerator> enumerator;
+  rv = GetMessageEnumerator(getter_AddRefs(enumerator));
+  if (NS_SUCCEEDED(rv) && enumerator)
+  {
+    bool hasMore;
+
+    while (NS_SUCCEEDED(rv = enumerator->HasMoreElements(&hasMore)) && hasMore)
+    {
+      nsCOMPtr <nsISupports> supports;
+      rv = enumerator->GetNext(getter_AddRefs(supports));
+      NS_ASSERTION(NS_SUCCEEDED(rv), "nsMsgDBEnumerator broken");
+      nsCOMPtr <nsIMsgDBHdr> pHeader = do_QueryInterface(supports);
+      if (pHeader && NS_SUCCEEDED(rv))
+      {
+        uint32_t flags;
+        pHeader->GetFlags(&flags);
+        if ((flags & nsMsgMessageFlags::Marked) && !(flags & nsMsgMessageFlags::Offline))
+          messageArray->AppendElement(pHeader, false);
+      }
+    }
+  }
+  m_folder->DownloadMessagesForOffline(messageArray, window);
+  return rv;
+}
+
+// read/unread handling.
+nsresult nsMsgDBView::ToggleReadByIndex(nsMsgViewIndex index)
+{
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  return SetReadByIndex(index, !(m_flags[index] & nsMsgMessageFlags::Read));
+}
+
+nsresult nsMsgDBView::SetReadByIndex(nsMsgViewIndex index, bool read)
+{
+  nsresult rv;
+
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  if (read)
+  {
+    OrExtraFlag(index, nsMsgMessageFlags::Read);
+    // MarkRead() will clear this flag in the db
+    // and then call OnKeyChange(), but
+    // because we are the instigator of the change
+    // we'll ignore the change.
+    //
+    // so we need to clear it in m_flags
+    // to keep the db and m_flags in sync
+    AndExtraFlag(index, ~nsMsgMessageFlags::New);
+  }
+  else
+  {
+    AndExtraFlag(index, ~nsMsgMessageFlags::Read);
+  }
+
+  nsCOMPtr <nsIMsgDatabase> dbToUse;
+  rv = GetDBForViewIndex(index, getter_AddRefs(dbToUse));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = dbToUse->MarkRead(m_keys[index], read, this);
+  NoteChange(index, 1, nsMsgViewNotificationCode::changed);
+  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+  {
+    nsMsgViewIndex threadIndex = GetThreadIndex(index);
+    if (threadIndex != index)
+      NoteChange(threadIndex, 1, nsMsgViewNotificationCode::changed);
+  }
+  return rv;
+}
+
+nsresult nsMsgDBView::SetThreadOfMsgReadByIndex(nsMsgViewIndex index, nsTArray<nsMsgKey> &keysMarkedRead, bool /*read*/)
+{
+  nsresult rv;
+
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  rv = MarkThreadOfMsgRead(m_keys[index], index, keysMarkedRead, true);
+  return rv;
+}
+
+nsresult nsMsgDBView::SetFlaggedByIndex(nsMsgViewIndex index, bool mark)
+{
+  nsresult rv;
+
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  nsCOMPtr <nsIMsgDatabase> dbToUse;
+  rv = GetDBForViewIndex(index, getter_AddRefs(dbToUse));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (mark)
+    OrExtraFlag(index, nsMsgMessageFlags::Marked);
+  else
+    AndExtraFlag(index, ~nsMsgMessageFlags::Marked);
+
+  rv = dbToUse->MarkMarked(m_keys[index], mark, this);
+  NoteChange(index, 1, nsMsgViewNotificationCode::changed);
+  return rv;
+}
+
+nsresult nsMsgDBView::SetMsgHdrJunkStatus(nsIJunkMailPlugin *aJunkPlugin,
+                                          nsIMsgDBHdr *aMsgHdr,
+                                          nsMsgJunkStatus aNewClassification)
+{
+    // get the old junk score
+    //
+    nsCString junkScoreStr;
+    nsresult rv = aMsgHdr->GetStringProperty("junkscore", getter_Copies(junkScoreStr));
+
+    // and the old origin
+    //
+    nsCString oldOriginStr;
+    rv = aMsgHdr->GetStringProperty("junkscoreorigin",
+                                   getter_Copies(oldOriginStr));
+
+    // if this was not classified by the user, say so
+    //
+    nsMsgJunkStatus oldUserClassification;
+    if (oldOriginStr.get()[0] != 'u') {
+        oldUserClassification = nsIJunkMailPlugin::UNCLASSIFIED;
+    }
+    else {
+        // otherwise, pass the actual user classification
+        if (junkScoreStr.IsEmpty())
+          oldUserClassification = nsIJunkMailPlugin::UNCLASSIFIED;
+        else if (junkScoreStr.ToInteger(&rv) == nsIJunkMailPlugin::IS_SPAM_SCORE)
+          oldUserClassification = nsIJunkMailPlugin::JUNK;
+        else
+          oldUserClassification = nsIJunkMailPlugin::GOOD;
+
+        NS_ASSERTION(NS_SUCCEEDED(rv), "Converting junkScore to integer failed.");
+    }
+
+    // get the URI for this message so we can pass it to the plugin
+    //
+    nsCString uri;
+    nsMsgKey msgKey;
+    nsCOMPtr<nsIMsgFolder> folder;
+    nsCOMPtr<nsIMsgDatabase> db;
+    aMsgHdr->GetMessageKey(&msgKey);
+    rv = aMsgHdr->GetFolder(getter_AddRefs(folder));
+    NS_ENSURE_SUCCESS(rv, rv);
+    GenerateURIForMsgKey(msgKey, folder, uri);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = folder->GetMsgDatabase(getter_AddRefs(db));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // tell the plugin about this change, so that it can (potentially)
+    // adjust its database appropriately
+    nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
+    rv = aJunkPlugin->SetMessageClassification(
+        uri.get(), oldUserClassification, aNewClassification, msgWindow, this);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // this routine is only reached if the user someone touched the UI
+    // and told us the junk status of this message.
+    // Set origin first so that listeners on the junkscore will
+    // know the correct origin.
+    rv = db->SetStringProperty(msgKey, "junkscoreorigin", "user");
+    NS_ASSERTION(NS_SUCCEEDED(rv), "SetStringPropertyByIndex failed");
+
+    // set the junk score on the message itself
+
+    nsAutoCString msgJunkScore;
+    msgJunkScore.AppendInt(aNewClassification == nsIJunkMailPlugin::JUNK ?
+          nsIJunkMailPlugin::IS_SPAM_SCORE:
+          nsIJunkMailPlugin::IS_HAM_SCORE);
+    db->SetStringProperty(msgKey, "junkscore", msgJunkScore.get());
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return rv;
+}
+
+nsresult
+nsMsgDBView::GetFolderFromMsgURI(const char *aMsgURI, nsIMsgFolder **aFolder)
+{
+  NS_IF_ADDREF(*aFolder = m_folder);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::OnMessageClassified(const char *aMsgURI,
+                                 nsMsgJunkStatus aClassification,
+                                 uint32_t aJunkPercent)
+
+{
+  // Note: we know all messages in a batch have the same
+  // classification, since unlike OnMessageClassified
+  // methods in other classes (such as nsLocalMailFolder
+  // and nsImapMailFolder), this class, nsMsgDBView, currently
+  // only triggers message classifications due to a command to
+  // mark some of the messages in the view as junk, or as not
+  // junk - so the classification is dictated to the filter,
+  // not suggested by it.
+  //
+  // for this reason the only thing we (may) have to do is
+  // perform the action on all of the junk messages
+  //
+
+  uint32_t numJunk;
+  mJunkHdrs->GetLength(&numJunk);
+  NS_ASSERTION((aClassification == nsIJunkMailPlugin::GOOD) ||
+                numJunk,
+                "the classification of a manually-marked junk message has"
+                "been classified as junk, yet there seem to be no such outstanding messages");
+
+  // is this the last message in the batch?
+
+  if (--mNumMessagesRemainingInBatch == 0 && numJunk > 0)
+  {
+    PerformActionsOnJunkMsgs(aClassification == nsIJunkMailPlugin::JUNK);
+    mJunkHdrs->Clear();
+  }
+  return NS_OK;
+}
+
+nsresult
+nsMsgDBView::PerformActionsOnJunkMsgs(bool msgsAreJunk)
+{
+  uint32_t numJunkHdrs;
+  mJunkHdrs->GetLength(&numJunkHdrs);
+  if (!numJunkHdrs)
+  {
+    NS_ERROR("no indices of marked-as-junk messages to act on");
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIMsgFolder> srcFolder;
+  nsCOMPtr<nsIMsgDBHdr> firstHdr(do_QueryElementAt(mJunkHdrs, 0));
+  firstHdr->GetFolder(getter_AddRefs(srcFolder));
+
+  bool moveMessages, changeReadState;
+  nsCOMPtr<nsIMsgFolder> targetFolder;
+
+  nsresult rv = DetermineActionsForJunkChange(msgsAreJunk, srcFolder,
+                                              moveMessages, changeReadState,
+                                              getter_AddRefs(targetFolder));
+  NS_ENSURE_SUCCESS(rv,rv);
+
+  // nothing to do, bail out
+  if (!(moveMessages || changeReadState))
+    return NS_OK;
+  if (changeReadState)
+  {
+    // notes on marking junk as read:
+    // 1. there are 2 occasions on which junk messages are marked as
+    //    read: after a manual marking (here and in the front end) and after
+    //    automatic classification by the bayesian filter (see code for local
+    //    mail folders and for imap mail folders). The server-specific
+    //    markAsReadOnSpam pref only applies to the latter, the former is
+    //    controlled by "mailnews.ui.junk.manualMarkAsJunkMarksRead".
+    // 2. even though move/delete on manual mark may be
+    //    turned off, we might still need to mark as read
+
+    NoteStartChange(nsMsgViewNotificationCode::none, 0, 0);
+    rv = srcFolder->MarkMessagesRead(mJunkHdrs, msgsAreJunk);
+    NoteEndChange(nsMsgViewNotificationCode::none, 0, 0);
+    NS_ASSERTION(NS_SUCCEEDED(rv), "marking marked-as-junk messages as read failed");
+  }
+  if (moveMessages)
+  {
+    // check if one of the messages to be junked is actually selected
+    // if more than one message being junked, one must be selected.
+    // if no tree selection at all, must be in stand-alone message window.
+    bool junkedMsgSelected = numJunkHdrs > 1 || !mTreeSelection;
+    for (nsMsgViewIndex junkIndex = 0; !junkedMsgSelected && junkIndex < numJunkHdrs; junkIndex++)
+    {
+      nsCOMPtr<nsIMsgDBHdr> junkHdr(do_QueryElementAt(mJunkHdrs, junkIndex, &rv));
+      NS_ENSURE_SUCCESS(rv, rv);
+      nsMsgViewIndex hdrIndex = FindHdr(junkHdr);
+      if (hdrIndex != nsMsgViewIndex_None)
+        mTreeSelection->IsSelected(hdrIndex, &junkedMsgSelected);
+    }
+
+    // if a junked msg is selected, tell the FE to call SetNextMessageAfterDelete() because a delete is coming
+    if (junkedMsgSelected && mCommandUpdater)
+    {
+      rv = mCommandUpdater->UpdateNextMessageAfterDelete();
+      NS_ENSURE_SUCCESS(rv,rv);
+    }
+
+    nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
+    NoteStartChange(nsMsgViewNotificationCode::none, 0, 0);
+    if (targetFolder)
+    {
+      nsCOMPtr<nsIMsgCopyService> copyService = do_GetService(NS_MSGCOPYSERVICE_CONTRACTID, &rv);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      rv = copyService->CopyMessages(srcFolder , mJunkHdrs, targetFolder,
+                                     true, nullptr, msgWindow, true);
+    }
+    else if (msgsAreJunk)
+    {
+      if (mDeleteModel == nsMsgImapDeleteModels::IMAPDelete)
+      {
+        // Unfortunately the DeleteMessages in this case is interpreted by IMAP as
+        //  a delete toggle. So what we have to do is to assemble a new delete
+        //  array, keeping only those that are not deleted.
+        //
+        nsCOMPtr<nsIMutableArray> hdrsToDelete = do_CreateInstance("@mozilla.org/array;1", &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
+        uint32_t cnt;
+        rv = mJunkHdrs->GetLength(&cnt);
+        for (uint32_t i = 0; i < cnt; i++)
+        {
+          nsCOMPtr<nsIMsgDBHdr> msgHdr = do_QueryElementAt(mJunkHdrs, i);
+          if (msgHdr)
+          {
+            uint32_t flags;
+            msgHdr->GetFlags(&flags);
+            if (!(flags & nsMsgMessageFlags::IMAPDeleted))
+              hdrsToDelete->AppendElement(msgHdr, false);
+          }
+        }
+        hdrsToDelete->GetLength(&cnt);
+        if (cnt)
+          rv = srcFolder->DeleteMessages(hdrsToDelete, msgWindow, false, false,
+                                         nullptr, true);
+      }
+      else
+        rv = srcFolder->DeleteMessages(mJunkHdrs, msgWindow, false, false,
+                                       nullptr, true);
+
+    }
+    else if (mDeleteModel == nsMsgImapDeleteModels::IMAPDelete)
+    {
+      nsCOMPtr<nsIMsgImapMailFolder> imapFolder(do_QueryInterface(srcFolder));
+      nsTArray<nsMsgKey> imapUids;
+      imapUids.SetLength(numJunkHdrs);
+      for (uint32_t i = 0; i < numJunkHdrs; i++)
+      {
+        nsCOMPtr<nsIMsgDBHdr> msgHdr = do_QueryElementAt(mJunkHdrs, i);
+        msgHdr->GetMessageKey(&imapUids[i]);
+      }
+
+      imapFolder->StoreImapFlags(kImapMsgDeletedFlag, false, imapUids.Elements(),
+                                 imapUids.Length(), nullptr);
+    }
+    NoteEndChange(nsMsgViewNotificationCode::none, 0, 0);
+
+    NS_ASSERTION(NS_SUCCEEDED(rv), "move or deletion of message marked-as-junk/non junk failed");
+  }
+  return rv;
+}
+
+nsresult
+nsMsgDBView::DetermineActionsForJunkChange(bool msgsAreJunk,
+                                           nsIMsgFolder *srcFolder,
+                                           bool &moveMessages,
+                                           bool &changeReadState,
+                                           nsIMsgFolder** targetFolder)
+{
+  // there are two possible actions which may be performed
+  // on messages marked as spam: marking as read and moving
+  // somewhere...When a message is marked as non junk,
+  // it may be moved to the inbox, and marked unread.
+
+  moveMessages = false;
+  changeReadState = false;
+
+  // ... the 'somewhere', junkTargetFolder, can be a folder,
+  // but if it remains null we'll delete the messages
+
+  *targetFolder = nullptr;
+
+  uint32_t folderFlags;
+  srcFolder->GetFlags(&folderFlags);
+
+  nsCOMPtr<nsIMsgIncomingServer> server;
+  nsresult rv = srcFolder->GetServer(getter_AddRefs(server));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIPrefBranch> prefBranch(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // handle the easy case of marking a junk message as good first...
+  // set the move target folder to the inbox, if any.
+  if (!msgsAreJunk)
+  {
+    if (folderFlags & nsMsgFolderFlags::Junk)
+    {
+      prefBranch->GetBoolPref("mail.spam.markAsNotJunkMarksUnRead",
+                              &changeReadState);
+      nsCOMPtr<nsIMsgFolder> rootMsgFolder;
+      rv = server->GetRootMsgFolder(getter_AddRefs(rootMsgFolder));
+      NS_ENSURE_SUCCESS(rv,rv);
+      rootMsgFolder->GetFolderWithFlags(nsMsgFolderFlags::Inbox, targetFolder);
+      moveMessages = targetFolder != nullptr;
+    }
+    return NS_OK;
+  }
+
+  nsCOMPtr <nsISpamSettings> spamSettings;
+  rv = server->GetSpamSettings(getter_AddRefs(spamSettings));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // When the user explicitly marks a message as junk, we can mark it as read,
+  // too. This is independent of the "markAsReadOnSpam" pref, which applies
+  // only to automatically-classified messages.
+  // Note that this behaviour should match the one in the front end for marking
+  // as junk via toolbar/context menu.
+  prefBranch->GetBoolPref("mailnews.ui.junk.manualMarkAsJunkMarksRead",
+                          &changeReadState);
+
+  // now let's determine whether we'll be taking the second action,
+  // the move / deletion (and also determine which of these two)
+
+  bool manualMark;
+  (void)spamSettings->GetManualMark(&manualMark);
+  if (!manualMark)
+    return NS_OK;
+
+  int32_t manualMarkMode;
+  (void)spamSettings->GetManualMarkMode(&manualMarkMode);
+  NS_ASSERTION(manualMarkMode == nsISpamSettings::MANUAL_MARK_MODE_MOVE
+            || manualMarkMode == nsISpamSettings::MANUAL_MARK_MODE_DELETE,
+            "bad manual mark mode");
+
+  if (manualMarkMode == nsISpamSettings::MANUAL_MARK_MODE_MOVE)
+  {
+    // if this is a junk folder
+    // (not only "the" junk folder for this account)
+    // don't do the move
+    if (folderFlags & nsMsgFolderFlags::Junk)
+      return NS_OK;
+
+    nsCString spamFolderURI;
+    rv = spamSettings->GetSpamFolderURI(getter_Copies(spamFolderURI));
+    NS_ENSURE_SUCCESS(rv,rv);
+
+    NS_ASSERTION(!spamFolderURI.IsEmpty(), "spam folder URI is empty, can't move");
+    if (!spamFolderURI.IsEmpty())
+    {
+      rv = GetExistingFolder(spamFolderURI, targetFolder);
+      if (NS_SUCCEEDED(rv) && *targetFolder)
+      {
+        moveMessages = true;
+      }
+      else
+      {
+        // XXX ToDo: GetOrCreateFolder will only create a folder with localized
+        //           name "Junk" regardless of spamFolderURI. So if someone
+        //           sets the junk folder to an existing folder of a different
+        //           name, then deletes that folder, this will fail to create
+        //           the correct folder.
+        rv = GetOrCreateFolder(spamFolderURI, nullptr /* aListener */);
+        if (NS_SUCCEEDED(rv))
+          rv = GetExistingFolder(spamFolderURI, targetFolder);
+        NS_ASSERTION(NS_SUCCEEDED(rv) && *targetFolder, "GetOrCreateFolder failed");
+      }
+    }
+    return NS_OK;
+  }
+
+  // at this point manualMarkMode == nsISpamSettings::MANUAL_MARK_MODE_DELETE)
+
+  // if this is in the trash, let's not delete
+  if (folderFlags & nsMsgFolderFlags::Trash)
+    return NS_OK;
+
+  return srcFolder->GetCanDeleteMessages(&moveMessages);
+}
+
+// reversing threads involves reversing the threads but leaving the
+// expanded messages ordered relative to the thread, so we
+// make a copy of each array and copy them over.
+void nsMsgDBView::ReverseThreads()
+{
+    nsTArray<uint32_t> newFlagArray;
+    nsTArray<nsMsgKey> newKeyArray;
+    nsTArray<uint8_t> newLevelArray;
+
+    uint32_t viewSize = GetSize();
+    uint32_t startThread = viewSize;
+    uint32_t nextThread = viewSize;
+    uint32_t destIndex = 0;
+
+    newKeyArray.SetLength(m_keys.Length());
+    newFlagArray.SetLength(m_flags.Length());
+    newLevelArray.SetLength(m_levels.Length());
+
+    while (startThread)
+    {
+        startThread--;
+
+        if (m_flags[startThread] & MSG_VIEW_FLAG_ISTHREAD)
+        {
+            for (uint32_t sourceIndex = startThread; sourceIndex < nextThread; sourceIndex++)
+            {
+                newKeyArray[destIndex] = m_keys[sourceIndex];
+                newFlagArray[destIndex] = m_flags[sourceIndex];
+                newLevelArray[destIndex] = m_levels[sourceIndex];
+                destIndex++;
+            }
+            nextThread = startThread; // because we're copying in reverse order
+        }
+    }
+    m_keys.SwapElements(newKeyArray);
+    m_flags.SwapElements(newFlagArray);
+    m_levels.SwapElements(newLevelArray);
+}
+
+void nsMsgDBView::ReverseSort()
+{
+    uint32_t topIndex = GetSize();
+
+    nsCOMArray<nsIMsgFolder> *folders = GetFolders();
+
+    // go up half the array swapping values
+    for (uint32_t bottomIndex = 0; bottomIndex < --topIndex; bottomIndex++)
+    {
+        // swap flags
+        uint32_t tempFlags = m_flags[bottomIndex];
+        m_flags[bottomIndex] = m_flags[topIndex];
+        m_flags[topIndex] = tempFlags;
+
+        // swap keys
+        nsMsgKey tempKey = m_keys[bottomIndex];
+        m_keys[bottomIndex] = m_keys[topIndex];
+        m_keys[topIndex] = tempKey;
+
+        if (folders)
+        {
+            // swap folders --
+            // needed when search is done across multiple folders
+            nsIMsgFolder *bottomFolder = folders->ObjectAt(bottomIndex);
+            nsIMsgFolder *topFolder = folders->ObjectAt(topIndex);
+            folders->ReplaceObjectAt(topFolder, bottomIndex);
+            folders->ReplaceObjectAt(bottomFolder, topIndex);
+        }
+        // no need to swap elements in m_levels; since we only call
+        // ReverseSort in non-threaded mode, m_levels are all the same.
+    }
+}
+int
+nsMsgDBView::FnSortIdKey(const void *pItem1, const void *pItem2, void *privateData)
+{
+    int32_t retVal = 0;
+
+    IdKey** p1 = (IdKey**)pItem1;
+    IdKey** p2 = (IdKey**)pItem2;
+    viewSortInfo* sortInfo = (viewSortInfo *) privateData;
+
+    nsIMsgDatabase *db = sortInfo->db;
+
+    mozilla::DebugOnly<nsresult> rv = db->CompareCollationKeys((*p1)->dword, (*p1)->key,
+                                                               (*p2)->dword, (*p2)->key,
+                                                               &retVal);
+    NS_ASSERTION(NS_SUCCEEDED(rv), "compare failed");
+
+    if (retVal)
+      return sortInfo->ascendingSort ? retVal : -retVal;
+    if (sortInfo->view->m_secondarySort == nsMsgViewSortType::byId)
+      return (sortInfo->view->m_secondarySortOrder == nsMsgViewSortOrder::ascending &&
+              (*p1)->id >= (*p2)->id) ? 1 : -1;
+    else
+      return sortInfo->view->SecondarySort((*p1)->id, (*p1)->folder, (*p2)->id, (*p2)->folder, sortInfo);
+    // here we'd use the secondary sort
+}
+
+int
+nsMsgDBView::FnSortIdKeyPtr(const void *pItem1, const void *pItem2, void *privateData)
+{
+  int32_t retVal = 0;
+
+  IdKeyPtr** p1 = (IdKeyPtr**)pItem1;
+  IdKeyPtr** p2 = (IdKeyPtr**)pItem2;
+  viewSortInfo* sortInfo = (viewSortInfo *) privateData;
+
+  nsIMsgDatabase *db = sortInfo->db;
+
+  mozilla::DebugOnly<nsresult> rv = db->CompareCollationKeys((*p1)->dword, (*p1)->key,
+                                                             (*p2)->dword, (*p2)->key,
+                                                             &retVal);
+  NS_ASSERTION(NS_SUCCEEDED(rv), "compare failed");
+
+  if (retVal)
+    return sortInfo->ascendingSort ? retVal : -retVal;
+
+  if (sortInfo->view->m_secondarySort == nsMsgViewSortType::byId)
+    return (sortInfo->view->m_secondarySortOrder == nsMsgViewSortOrder::ascending &&
+            (*p1)->id >= (*p2)->id) ? 1 : -1;
+  else
+    return sortInfo->view->SecondarySort((*p1)->id, (*p1)->folder, (*p2)->id, (*p2)->folder, sortInfo);
+}
+
+int
+nsMsgDBView::FnSortIdUint32(const void *pItem1, const void *pItem2, void *privateData)
+{
+  IdUint32** p1 = (IdUint32**)pItem1;
+  IdUint32** p2 = (IdUint32**)pItem2;
+  viewSortInfo* sortInfo = (viewSortInfo *) privateData;
+
+  if ((*p1)->dword > (*p2)->dword)
+    return (sortInfo->ascendingSort) ? 1 : -1;
+  else if ((*p1)->dword < (*p2)->dword)
+      return (sortInfo->ascendingSort) ? -1 : 1;
+  if (sortInfo->view->m_secondarySort == nsMsgViewSortType::byId)
+    return (sortInfo->view->m_secondarySortOrder == nsMsgViewSortOrder::ascending &&
+            (*p1)->id >= (*p2)->id) ? 1 : -1;
+  else
+    return sortInfo->view->SecondarySort((*p1)->id, (*p1)->folder, (*p2)->id, (*p2)->folder, sortInfo);
+}
+
+
+// XXX are these still correct?
+//To compensate for memory alignment required for
+//systems such as HP-UX these values must be 4 bytes
+//aligned.  Don't break this when modify the constants
+const int kMaxSubjectKey = 160;
+const int kMaxLocationKey = 160;  // also used for account
+const int kMaxAuthorKey = 160;
+const int kMaxRecipientKey = 80;
+
+//
+// There are cases when pFieldType is not set:
+// one case returns NS_ERROR_UNEXPECTED;
+// the other case now return NS_ERROR_NULL_POINTER (this is only when
+// colHandler below is null, but is very unlikely).
+// The latter case used to return NS_OK, which was incorrect.
+//
+nsresult nsMsgDBView::GetFieldTypeAndLenForSort(nsMsgViewSortTypeValue sortType,
+                                                uint16_t *pMaxLen,
+                                                eFieldType *pFieldType,
+                                                nsIMsgCustomColumnHandler* colHandler)
+{
+    NS_ENSURE_ARG_POINTER(pMaxLen);
+    NS_ENSURE_ARG_POINTER(pFieldType);
+
+    switch (sortType)
+    {
+        case nsMsgViewSortType::bySubject:
+            *pFieldType = kCollationKey;
+            *pMaxLen = kMaxSubjectKey;
+            break;
+        case nsMsgViewSortType::byAccount:
+        case nsMsgViewSortType::byTags:
+        case nsMsgViewSortType::byLocation:
+            *pFieldType = kCollationKey;
+            *pMaxLen = kMaxLocationKey;
+            break;
+        case nsMsgViewSortType::byRecipient:
+        case nsMsgViewSortType::byCorrespondent:
+            *pFieldType = kCollationKey;
+            *pMaxLen = kMaxRecipientKey;
+            break;
+        case nsMsgViewSortType::byAuthor:
+            *pFieldType = kCollationKey;
+            *pMaxLen = kMaxAuthorKey;
+            break;
+        case nsMsgViewSortType::byDate:
+        case nsMsgViewSortType::byReceived:
+        case nsMsgViewSortType::byPriority:
+        case nsMsgViewSortType::byThread:
+        case nsMsgViewSortType::byId:
+        case nsMsgViewSortType::bySize:
+        case nsMsgViewSortType::byFlagged:
+        case nsMsgViewSortType::byUnread:
+        case nsMsgViewSortType::byStatus:
+        case nsMsgViewSortType::byJunkStatus:
+        case nsMsgViewSortType::byAttachments:
+            *pFieldType = kU32;
+            *pMaxLen = 0;
+            break;
+        case nsMsgViewSortType::byCustom:
+        {
+          if (colHandler == nullptr)
+          {
+            NS_WARNING("colHandler is null. *pFieldType is not set.");
+            return NS_ERROR_NULL_POINTER;
+          }
+
+          bool isString;
+          colHandler->IsString(&isString);
+
+          if (isString)
+          {
+            *pFieldType = kCollationKey;
+            *pMaxLen = kMaxRecipientKey; //80 - do we need a seperate k?
+          }
+          else
+          {
+            *pFieldType = kU32;
+            *pMaxLen = 0;
+          }
+          break;
+        }
+        case nsMsgViewSortType::byNone: // bug 901948
+          return NS_ERROR_INVALID_ARG;
+        default:
+        {
+           nsAutoCString message("unexpected switch value: sortType=");
+           message.AppendInt(sortType);
+           NS_WARNING(message.get());
+           return NS_ERROR_UNEXPECTED;
+        }
+    }
+
+    return NS_OK;
+}
+
+#define MSG_STATUS_MASK (nsMsgMessageFlags::Replied | nsMsgMessageFlags::Forwarded)
+
+nsresult nsMsgDBView::GetStatusSortValue(nsIMsgDBHdr *msgHdr, uint32_t *result)
+{
+  NS_ENSURE_ARG_POINTER(msgHdr);
+  NS_ENSURE_ARG_POINTER(result);
+
+  uint32_t messageFlags;
+  nsresult rv = msgHdr->GetFlags(&messageFlags);
+  NS_ENSURE_SUCCESS(rv,rv);
+
+  if (messageFlags & nsMsgMessageFlags::New)
+  {
+    // happily, new by definition stands alone
+    *result = 0;
+    return NS_OK;
+  }
+
+  switch (messageFlags & MSG_STATUS_MASK)
+  {
+    case nsMsgMessageFlags::Replied:
+        *result = 2;
+        break;
+    case nsMsgMessageFlags::Forwarded | nsMsgMessageFlags::Replied:
+        *result = 1;
+        break;
+    case nsMsgMessageFlags::Forwarded:
+        *result = 3;
+        break;
+    default:
+        *result = (messageFlags & nsMsgMessageFlags::Read) ? 4 : 5;
+        break;
+    }
+
+    return NS_OK;
+}
+
+nsresult nsMsgDBView::GetLongField(nsIMsgDBHdr *msgHdr, nsMsgViewSortTypeValue sortType, uint32_t *result, nsIMsgCustomColumnHandler* colHandler)
+{
+  nsresult rv;
+  NS_ENSURE_ARG_POINTER(msgHdr);
+  NS_ENSURE_ARG_POINTER(result);
+
+  bool isRead;
+  uint32_t bits;
+
+  switch (sortType)
+  {
+    case nsMsgViewSortType::bySize:
+      rv = (mShowSizeInLines) ? msgHdr->GetLineCount(result) : msgHdr->GetMessageSize(result);
+      break;
+    case nsMsgViewSortType::byPriority:
+        nsMsgPriorityValue priority;
+        rv = msgHdr->GetPriority(&priority);
+
+        // treat "none" as "normal" when sorting.
+        if (priority == nsMsgPriority::none)
+            priority = nsMsgPriority::normal;
+
+        // we want highest priority to have lowest value
+        // so ascending sort will have highest priority first.
+        *result = nsMsgPriority::highest - priority;
+        break;
+    case nsMsgViewSortType::byStatus:
+        rv = GetStatusSortValue(msgHdr,result);
+        break;
+    case nsMsgViewSortType::byFlagged:
+        bits = 0;
+        rv = msgHdr->GetFlags(&bits);
+        *result = !(bits & nsMsgMessageFlags::Marked);  //make flagged come out on top.
+        break;
+    case nsMsgViewSortType::byUnread:
+        rv = msgHdr->GetIsRead(&isRead);
+        if (NS_SUCCEEDED(rv))
+            *result = !isRead;
+        break;
+    case nsMsgViewSortType::byJunkStatus:
+      {
+        nsCString junkScoreStr;
+        rv = msgHdr->GetStringProperty("junkscore", getter_Copies(junkScoreStr));
+        // unscored messages should come before messages that are scored
+        // junkScoreStr is "", and "0" - "100"
+        // normalize to 0 - 101
+        *result = junkScoreStr.IsEmpty() ? (0) : atoi(junkScoreStr.get()) + 1;
+      }
+      break;
+     case nsMsgViewSortType::byAttachments:
+        bits = 0;
+        rv = msgHdr->GetFlags(&bits);
+        *result = !(bits & nsMsgMessageFlags::Attachment);
+      break;
+    case nsMsgViewSortType::byDate:
+      // when sorting threads by date, we may want the date of the newest msg
+      // in the thread
+      if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay
+        && ! (m_viewFlags & nsMsgViewFlagsType::kGroupBySort)
+        && ! mSortThreadsByRoot)
+      {
+        nsCOMPtr <nsIMsgThread> thread;
+        rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(thread));
+        if (NS_SUCCEEDED(rv))
+        {
+          thread->GetNewestMsgDate(result);
+          break;
+        }
+      }
+      rv = msgHdr->GetDateInSeconds(result);
+      break;
+    case nsMsgViewSortType::byReceived:
+      // when sorting threads by received date, we may want the received date
+      // of the newest msg in the thread
+      if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay
+        && ! (m_viewFlags & nsMsgViewFlagsType::kGroupBySort)
+        && ! mSortThreadsByRoot)
+      {
+        nsCOMPtr <nsIMsgThread> thread;
+        rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(thread));
+        NS_ENSURE_SUCCESS(rv, rv);
+        thread->GetNewestMsgDate(result);
+      }
+      else
+      {
+        rv = msgHdr->GetUint32Property("dateReceived", result);  // Already in seconds...
+        if (*result == 0)  // Use Date instead, we have no Received property
+          rv = msgHdr->GetDateInSeconds(result);
+      }
+      break;
+    case nsMsgViewSortType::byCustom:
+      if (colHandler != nullptr)
+      {
+        colHandler->GetSortLongForRow(msgHdr, result);
+        rv = NS_OK;
+      }
+      else
+      {
+        NS_ASSERTION(false, "should not be here (Sort Type: byCustom (Long), but no custom handler)");
+        rv = NS_ERROR_UNEXPECTED;
+      }
+      break;
+    case nsMsgViewSortType::byNone: // Bug 901948
+      return NS_ERROR_INVALID_ARG;
+
+    case nsMsgViewSortType::byId:
+        // handled by caller, since caller knows the key
+    default:
+        NS_ERROR("should not be here");
+        rv = NS_ERROR_UNEXPECTED;
+        break;
+    }
+
+    NS_ENSURE_SUCCESS(rv,rv);
+    return NS_OK;
+}
+
+MsgViewSortColumnInfo::MsgViewSortColumnInfo(const MsgViewSortColumnInfo &other)
+{
+  mSortType = other.mSortType;
+  mSortOrder = other.mSortOrder;
+  mCustomColumnName = other.mCustomColumnName;
+  mColHandler = other.mColHandler;
+}
+
+bool MsgViewSortColumnInfo::operator== (const MsgViewSortColumnInfo& other) const
+{
+  return (mSortType == nsMsgViewSortType::byCustom) ?
+    mCustomColumnName.Equals(other.mCustomColumnName) : mSortType == other.mSortType;
+}
+
+nsresult nsMsgDBView::EncodeColumnSort(nsString &columnSortString)
+{
+  for (uint32_t i = 0; i < m_sortColumns.Length(); i++)
+  {
+    MsgViewSortColumnInfo &sortInfo = m_sortColumns[i];
+    columnSortString.Append((char) sortInfo.mSortType);
+    columnSortString.Append((char) sortInfo.mSortOrder + '0');
+    if (sortInfo.mSortType == nsMsgViewSortType::byCustom)
+    {
+      columnSortString.Append(sortInfo.mCustomColumnName);
+      columnSortString.Append((char16_t) '\r');
+    }
+  }
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::DecodeColumnSort(nsString &columnSortString)
+{
+  const char16_t *stringPtr = columnSortString.BeginReading();
+  while (*stringPtr)
+  {
+    MsgViewSortColumnInfo sortColumnInfo;
+    sortColumnInfo.mSortType = (nsMsgViewSortTypeValue) *stringPtr++;
+    sortColumnInfo.mSortOrder = (nsMsgViewSortOrderValue) (*stringPtr++) - '0';
+    if (sortColumnInfo.mSortType == nsMsgViewSortType::byCustom)
+    {
+      while (*stringPtr && *stringPtr != '\r')
+        sortColumnInfo.mCustomColumnName.Append(*stringPtr++);
+      sortColumnInfo.mColHandler = GetColumnHandler(sortColumnInfo.mCustomColumnName.get());
+      if (*stringPtr) // advance past '\r'
+        stringPtr++;
+    }
+    m_sortColumns.AppendElement(sortColumnInfo);
+  }
+  return NS_OK;
+}
+
+//  cf. Secondary Sort Key: when you select a column to sort, that
+//  becomes the new Primary sort key, and all previous sort keys
+//  become secondary. For example, if you first click on Date,
+//  the messages are sorted by Date; then click on From, and now the
+//  messages are sorted by From, and for each value of From the
+//  messages are in Date order.
+
+void nsMsgDBView::PushSort(const MsgViewSortColumnInfo &newSort)
+{
+  // DONE
+  //  Handle byNone (bug 901948) ala a mail/base/modules/dbViewerWrapper.js
+  //  where we don't push the secondary sort type if it's ::byNone;
+  //  (and secondary sort type is NOT the same as the first sort type
+  //  there.). This code should behave the same way.
+
+  // We don't expect to be passed sort type ::byNone,
+  // but if we are it's safe to ignore it.
+  if (newSort.mSortType == nsMsgViewSortType::byNone)
+    return;
+
+  // Date and ID are unique keys, so if we are sorting by them we don't
+  // need to keep any secondary sort keys
+  if (newSort.mSortType == nsMsgViewSortType::byDate ||
+      newSort.mSortType == nsMsgViewSortType::byId   )
+    m_sortColumns.Clear();
+  m_sortColumns.RemoveElement(newSort);
+  m_sortColumns.InsertElementAt(0, newSort);
+  if (m_sortColumns.Length() > kMaxNumSortColumns)
+    m_sortColumns.RemoveElementAt(kMaxNumSortColumns);
+}
+
+nsresult
+nsMsgDBView::GetCollationKey(nsIMsgDBHdr *msgHdr, nsMsgViewSortTypeValue sortType, uint8_t **result, uint32_t *len, nsIMsgCustomColumnHandler* colHandler)
+{
+  nsresult rv = NS_ERROR_UNEXPECTED;
+  NS_ENSURE_ARG_POINTER(msgHdr);
+  NS_ENSURE_ARG_POINTER(result);
+
+  switch (sortType)
+  {
+    case nsMsgViewSortType::bySubject:
+        rv = msgHdr->GetSubjectCollationKey(len, result);
+        break;
+    case nsMsgViewSortType::byLocation:
+        rv = GetLocationCollationKey(msgHdr, result, len);
+        break;
+    case nsMsgViewSortType::byRecipient:
+      {
+        nsString recipients;
+        rv = FetchRecipients(msgHdr, recipients);
+        if (NS_SUCCEEDED(rv))
+        {
+          nsCOMPtr <nsIMsgDatabase> dbToUse = m_db;
+          if (!dbToUse) // probably search view
+          {
+            rv = GetDBForHeader(msgHdr, getter_AddRefs(dbToUse));
+            NS_ENSURE_SUCCESS(rv,rv);
+          }
+          rv = dbToUse->CreateCollationKey(recipients, len, result);
+        }
+      }
+      break;
+    case nsMsgViewSortType::byAuthor:
+      {
+        rv = msgHdr->GetAuthorCollationKey(len, result);
+        nsString author;
+        rv = FetchAuthor(msgHdr, author);
+        if (NS_SUCCEEDED(rv))
+        {
+          nsCOMPtr <nsIMsgDatabase> dbToUse = m_db;
+          if (!dbToUse) // probably search view
+          {
+            rv = GetDBForHeader(msgHdr, getter_AddRefs(dbToUse));
+            NS_ENSURE_SUCCESS(rv,rv);
+          }
+          rv = dbToUse->CreateCollationKey(author, len, result);
+        }
+      }
+      break;
+    case nsMsgViewSortType::byAccount:
+    case nsMsgViewSortType::byTags:
+      {
+        nsString str;
+        nsCOMPtr <nsIMsgDatabase> dbToUse = m_db;
+
+        if (!dbToUse) // probably search view
+          GetDBForViewIndex(0, getter_AddRefs(dbToUse));
+
+        rv = (sortType == nsMsgViewSortType::byAccount)
+            ? FetchAccount(msgHdr, str)
+            : FetchTags(msgHdr, str);
+
+        if (NS_SUCCEEDED(rv) && dbToUse)
+          rv = dbToUse->CreateCollationKey(str, len, result);
+      }
+      break;
+    case nsMsgViewSortType::byCustom:
+      if (colHandler != nullptr)
+      {
+        nsAutoString strKey;
+        rv = colHandler->GetSortStringForRow(msgHdr, strKey);
+        NS_ASSERTION(NS_SUCCEEDED(rv),"failed to get sort string for custom row");
+        nsAutoString strTemp(strKey);
+
+        nsCOMPtr <nsIMsgDatabase> dbToUse = m_db;
+        if (!dbToUse) // probably search view
+        {
+          rv = GetDBForHeader(msgHdr, getter_AddRefs(dbToUse));
+          NS_ENSURE_SUCCESS(rv,rv);
+        }
+        rv = dbToUse->CreateCollationKey(strKey, len, result);
+      }
+      else
+      {
+        NS_ERROR("should not be here (Sort Type: byCustom (String), but no custom handler)");
+        rv = NS_ERROR_UNEXPECTED;
+      }
+      break;
+    case nsMsgViewSortType::byCorrespondent:
+      {
+        nsString value;
+        if (IsOutgoingMsg(msgHdr))
+          rv = FetchRecipients(msgHdr, value);
+        else
+          rv = FetchAuthor(msgHdr, value);
+        if (NS_SUCCEEDED(rv))
+        {
+          nsCOMPtr <nsIMsgDatabase> dbToUse = m_db;
+          if (!dbToUse) // probably search view
+          {
+            rv = GetDBForHeader(msgHdr, getter_AddRefs(dbToUse));
+            NS_ENSURE_SUCCESS(rv,rv);
+          }
+          rv = dbToUse->CreateCollationKey(value, len, result);
+        }
+      }
+      break;
+    default:
+        rv = NS_ERROR_UNEXPECTED;
+        break;
+    }
+
+    // bailing out with failure will stop the sort and leave us in
+    // a bad state.  try to continue on, instead
+    NS_ASSERTION(NS_SUCCEEDED(rv),"failed to get the collation key");
+    if (NS_FAILED(rv))
+    {
+        *result = nullptr;
+        *len = 0;
+    }
+    return NS_OK;
+}
+
+// As the location collation key is created getting folder from the msgHdr,
+// it is defined in this file and not from the db.
+nsresult
+nsMsgDBView::GetLocationCollationKey(nsIMsgDBHdr *msgHdr, uint8_t **result, uint32_t *len)
+{
+  nsCOMPtr <nsIMsgFolder> folder;
+
+  nsresult rv = msgHdr->GetFolder(getter_AddRefs(folder));
+  NS_ENSURE_SUCCESS(rv,rv);
+  nsCOMPtr <nsIMsgDatabase> dbToUse;
+  rv = folder->GetMsgDatabase(getter_AddRefs(dbToUse));
+  NS_ENSURE_SUCCESS(rv,rv);
+
+  nsString locationString;
+  rv = folder->GetPrettiestName(locationString);
+  NS_ENSURE_SUCCESS(rv,rv);
+
+  return dbToUse->CreateCollationKey(locationString, len, result);
+}
+
+nsresult nsMsgDBView::SaveSortInfo(nsMsgViewSortTypeValue sortType, nsMsgViewSortOrderValue sortOrder)
+{
+  if (m_viewFolder)
+  {
+    nsCOMPtr <nsIDBFolderInfo> folderInfo;
+    nsCOMPtr <nsIMsgDatabase> db;
+    nsresult rv = m_viewFolder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo), getter_AddRefs(db));
+    if (NS_SUCCEEDED(rv) && folderInfo)
+    {
+      // save off sort type and order, view type and flags
+      folderInfo->SetSortType(sortType);
+      folderInfo->SetSortOrder(sortOrder);
+
+      nsString sortColumnsString;
+      rv = EncodeColumnSort(sortColumnsString);
+      NS_ENSURE_SUCCESS(rv, rv);
+      folderInfo->SetProperty("sortColumns", sortColumnsString);
+    }
+  }
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::RestoreSortInfo()
+{
+  if (!m_viewFolder)
+    return NS_OK;
+
+  nsCOMPtr <nsIDBFolderInfo> folderInfo;
+  nsCOMPtr <nsIMsgDatabase> db;
+  nsresult rv = m_viewFolder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo), getter_AddRefs(db));
+  if (NS_SUCCEEDED(rv) && folderInfo)
+  {
+    // Restore m_sortColumns from db.
+    nsString sortColumnsString;
+    folderInfo->GetProperty("sortColumns", sortColumnsString);
+    DecodeColumnSort(sortColumnsString);
+    if (m_sortColumns.Length() > 1)
+    {
+      m_secondarySort = m_sortColumns[1].mSortType;
+      m_secondarySortOrder = m_sortColumns[1].mSortOrder;
+      m_secondaryCustomColumn = m_sortColumns[1].mCustomColumnName;
+    }
+
+    // Restore curCustomColumn from db.
+    folderInfo->GetProperty("customSortCol", m_curCustomColumn);
+  }
+
+  return NS_OK;
+}
+
+// Called by msgDBView::Sort, at which point any persisted active custom
+// columns must be registered. If not, reset their m_sortColumns entries
+// to byDate; Sort will fill in values if necessary based on new user sort.
+void nsMsgDBView::EnsureCustomColumnsValid()
+{
+  if (!m_sortColumns.Length())
+    return;
+
+  for (uint32_t i = 0; i < m_sortColumns.Length(); i++)
+  {
+    if (m_sortColumns[i].mSortType == nsMsgViewSortType::byCustom &&
+        m_sortColumns[i].mColHandler == nullptr)
+    {
+      m_sortColumns[i].mSortType = nsMsgViewSortType::byDate;
+      m_sortColumns[i].mCustomColumnName.Truncate();
+      // There are only two...
+      if (i == 0 && m_sortType != nsMsgViewSortType::byCustom)
+        SetCurCustomColumn(EmptyString());
+      if (i == 1)
+        m_secondaryCustomColumn.Truncate();
+    }
+  }
+}
+
+int32_t  nsMsgDBView::SecondarySort(nsMsgKey key1, nsISupports *supports1,
+                                    nsMsgKey key2, nsISupports *supports2,
+                                    viewSortInfo *comparisonContext)
+{
+  // We need to make sure that in the case of the secondary sort field also
+  // matching, we don't recurse.
+  if (comparisonContext->isSecondarySort)
+    return key1 > key2;
+
+  nsCOMPtr<nsIMsgFolder> folder1, folder2;
+  nsCOMPtr <nsIMsgDBHdr> hdr1, hdr2;
+  folder1 = do_QueryInterface(supports1);
+  folder2 = do_QueryInterface(supports2);
+  nsresult rv = folder1->GetMessageHeader(key1, getter_AddRefs(hdr1));
+  NS_ENSURE_SUCCESS(rv, 0);
+  rv = folder2->GetMessageHeader(key2, getter_AddRefs(hdr2));
+  NS_ENSURE_SUCCESS(rv, 0);
+  IdKeyPtr EntryInfo1, EntryInfo2;
+  EntryInfo1.key = nullptr;
+  EntryInfo2.key = nullptr;
+
+  uint16_t  maxLen;
+  eFieldType fieldType;
+  nsMsgViewSortTypeValue sortType = comparisonContext->view->m_secondarySort;
+  nsMsgViewSortOrderValue sortOrder = comparisonContext->view->m_secondarySortOrder;
+
+  // Get the custom column handler for the *secondary* sort and pass it first
+  // to GetFieldTypeAndLenForSort to get the fieldType and then either
+  // GetCollationKey or GetLongField.
+  nsIMsgCustomColumnHandler* colHandler = nullptr;
+  if (sortType == nsMsgViewSortType::byCustom &&
+      comparisonContext->view->m_sortColumns.Length() > 1)
+    colHandler = comparisonContext->view->m_sortColumns[1].mColHandler;
+
+  // The following may leave fieldType undefined.
+  // In this case, we can return 0 right away since
+  // it is the value returned in the default case of
+  // switch (fieldType) statement below.
+  rv = GetFieldTypeAndLenForSort(sortType, &maxLen, &fieldType, colHandler);
+  NS_ENSURE_SUCCESS(rv, 0);
+
+  const void *pValue1 = &EntryInfo1, *pValue2 = &EntryInfo2;
+
+  int (* comparisonFun) (const void *pItem1, const void *pItem2, void *privateData) = nullptr;
+  int retStatus = 0;
+  hdr1->GetMessageKey(&EntryInfo1.id);
+  hdr2->GetMessageKey(&EntryInfo2.id);
+
+  switch (fieldType)
+  {
+    case kCollationKey:
+      rv = GetCollationKey(hdr1, sortType, &EntryInfo1.key, &EntryInfo1.dword, colHandler);
+      NS_ASSERTION(NS_SUCCEEDED(rv),"failed to create collation key");
+      comparisonFun = FnSortIdKeyPtr;
+      break;
+    case kU32:
+      if (sortType == nsMsgViewSortType::byId)
+        EntryInfo1.dword = EntryInfo1.id;
+      else
+        GetLongField(hdr1, sortType, &EntryInfo1.dword, colHandler);
+      comparisonFun = FnSortIdUint32;
+      break;
+    default:
+      return 0;
+  }
+  bool saveAscendingSort = comparisonContext->ascendingSort;
+  comparisonContext->isSecondarySort = true;
+  comparisonContext->ascendingSort = (sortOrder == nsMsgViewSortOrder::ascending);
+  if (fieldType == kCollationKey)
+  {
+    PR_FREEIF(EntryInfo2.key);
+    rv = GetCollationKey(hdr2, sortType, &EntryInfo2.key, &EntryInfo2.dword, colHandler);
+    NS_ASSERTION(NS_SUCCEEDED(rv),"failed to create collation key");
+  }
+  else if (fieldType == kU32)
+  {
+    if (sortType == nsMsgViewSortType::byId)
+      EntryInfo2.dword = EntryInfo2.id;
+    else
+      GetLongField(hdr2, sortType, &EntryInfo2.dword, colHandler);
+  }
+  retStatus = (*comparisonFun)(&pValue1, &pValue2, comparisonContext);
+
+  comparisonContext->isSecondarySort = false;
+  comparisonContext->ascendingSort = saveAscendingSort;
+
+  return retStatus;
+}
+
+
+NS_IMETHODIMP nsMsgDBView::Sort(nsMsgViewSortTypeValue sortType,
+                                nsMsgViewSortOrderValue sortOrder)
+{
+  EnsureCustomColumnsValid();
+
+  // If we're doing a stable sort, we can't just reverse the messages.
+  // Check also that the custom column we're sorting on hasn't changed.
+  // Otherwise, to be on the safe side, resort.
+  // Note: m_curCustomColumn is the desired (possibly new) custom column name,
+  // while m_sortColumns[0].mCustomColumnName is the name for the last completed
+  // sort, since these are persisted after each sort.
+  if (m_sortType == sortType && m_sortValid &&
+      (sortType != nsMsgViewSortType::byCustom ||
+       (sortType == nsMsgViewSortType::byCustom && m_sortColumns.Length() &&
+        m_sortColumns[0].mCustomColumnName.Equals(m_curCustomColumn))) &&
+      m_sortColumns.Length() < 2)
+  {
+    // same as it ever was.  do nothing
+    if (m_sortOrder == sortOrder)
+      return NS_OK;
+
+    // for secondary sort, remember the sort order on a per column basis.
+    if (m_sortColumns.Length())
+      m_sortColumns[0].mSortOrder = sortOrder;
+    SaveSortInfo(sortType, sortOrder);
+    if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+      ReverseThreads();
+    else
+      ReverseSort();
+
+    m_sortOrder = sortOrder;
+    // we just reversed the sort order...we still need to invalidate the view
+    return NS_OK;
+  }
+
+  if (sortType == nsMsgViewSortType::byThread)
+    return NS_OK;
+
+  // If a sortType has changed, or the sortType is byCustom and a column has
+  // changed, this is the new primary sortColumnInfo.
+  // Note: m_curCustomColumn is the desired (possibly new) custom column name,
+  // while m_sortColumns[0].mCustomColumnName is the name for the last completed
+  // sort, since these are persisted after each sort.
+  if (m_sortType != sortType ||
+      (sortType == nsMsgViewSortType::byCustom && m_sortColumns.Length() &&
+       !m_sortColumns[0].mCustomColumnName.Equals(m_curCustomColumn)))
+  {
+    // For secondary sort, remember the sort order of the original primary sort!
+    if (m_sortColumns.Length())
+      m_sortColumns[0].mSortOrder = m_sortOrder;
+
+    MsgViewSortColumnInfo sortColumnInfo;
+    sortColumnInfo.mSortType = sortType;
+    sortColumnInfo.mSortOrder = sortOrder;
+    if (sortType == nsMsgViewSortType::byCustom)
+    {
+      GetCurCustomColumn(sortColumnInfo.mCustomColumnName);
+      sortColumnInfo.mColHandler = GetCurColumnHandler();
+    }
+
+    PushSort(sortColumnInfo);
+  }
+  else
+  {
+    // For primary sort, remember the sort order on a per column basis.
+    if (m_sortColumns.Length())
+      m_sortColumns[0].mSortOrder = sortOrder;
+  }
+
+  if (m_sortColumns.Length() > 1)
+  {
+    m_secondarySort = m_sortColumns[1].mSortType;
+    m_secondarySortOrder = m_sortColumns[1].mSortOrder;
+    m_secondaryCustomColumn = m_sortColumns[1].mCustomColumnName;
+  }
+  SaveSortInfo(sortType, sortOrder);
+  // figure out how much memory we'll need, and the malloc it
+  uint16_t maxLen;
+  eFieldType fieldType;
+
+  // Get the custom column handler for the primary sort and pass it first
+  // to GetFieldTypeAndLenForSort to get the fieldType and then either
+  // GetCollationKey or GetLongField.
+  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();
+
+  // If we did not obtain proper fieldType, it needs to be checked
+  // because the subsequent code does not handle it very well.
+  nsresult rv = GetFieldTypeAndLenForSort(sortType, &maxLen, &fieldType, colHandler);
+
+  // Don't sort if the field type is not supported: Bug 901948
+  if (NS_FAILED(rv))
+    return NS_OK;
+
+  nsTArray<void*> ptrs;
+  uint32_t arraySize = GetSize();
+
+  if (!arraySize)
+    return NS_OK;
+
+  nsCOMArray<nsIMsgFolder> *folders = GetFolders();
+
+  IdKey** pPtrBase = (IdKey**)PR_Malloc(arraySize * sizeof(IdKey*));
+  NS_ASSERTION(pPtrBase, "out of memory, can't sort");
+  if (!pPtrBase) return NS_ERROR_OUT_OF_MEMORY;
+  ptrs.AppendElement((void *)pPtrBase); // remember this pointer so we can free it later
+
+  // build up the beast, so we can sort it.
+  uint32_t numSoFar = 0;
+  const uint32_t keyOffset = offsetof(IdKey, key);
+  // calc max possible size needed for all the rest
+  uint32_t maxSize = (keyOffset + maxLen) * (arraySize - numSoFar);
+
+  const uint32_t maxBlockSize = (uint32_t) 0xf000L;
+  uint32_t allocSize = std::min(maxBlockSize, maxSize);
+  char *pTemp = (char *) PR_Malloc(allocSize);
+  NS_ASSERTION(pTemp, "out of memory, can't sort");
+  if (!pTemp)
+  {
+    FreeAll(&ptrs);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  ptrs.AppendElement(pTemp); // remember this pointer so we can free it later
+
+  char *pBase = pTemp;
+  bool more = true;
+
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  uint8_t *keyValue = nullptr;
+  uint32_t longValue;
+  while (more && numSoFar < arraySize)
+  {
+    nsMsgKey thisKey = m_keys[numSoFar];
+    if (sortType != nsMsgViewSortType::byId)
+    {
+      rv = GetMsgHdrForViewIndex(numSoFar, getter_AddRefs(msgHdr));
+      NS_ASSERTION(NS_SUCCEEDED(rv) && msgHdr, "header not found");
+      if (NS_FAILED(rv) || !msgHdr)
+      {
+        FreeAll(&ptrs);
+        return NS_ERROR_UNEXPECTED;
+      }
+    }
+    else
+    {
+      msgHdr = nullptr;
+    }
+
+    // Could be a problem here if the ones that appear here are different than
+    // the ones already in the array.
+    uint32_t actualFieldLen = 0;
+
+    if (fieldType == kCollationKey)
+    {
+      rv = GetCollationKey(msgHdr, sortType, &keyValue, &actualFieldLen, colHandler);
+      NS_ENSURE_SUCCESS(rv,rv);
+
+      longValue = actualFieldLen;
+    }
+    else
+    {
+      if (sortType == nsMsgViewSortType::byId)
+      {
+        longValue = thisKey;
+      }
+      else
+      {
+        rv = GetLongField(msgHdr, sortType, &longValue, colHandler);
+        NS_ENSURE_SUCCESS(rv,rv);
+      }
+    }
+
+    // check to see if this entry fits into the block we have allocated so far
+    // pTemp - pBase = the space we have used so far
+    // sizeof(EntryInfo) + fieldLen = space we need for this entry
+    // allocSize = size of the current block
+    if ((uint32_t)(pTemp - pBase) + (keyOffset + actualFieldLen) >= allocSize)
+    {
+      maxSize = (keyOffset + maxLen) * (arraySize - numSoFar);
+      allocSize = std::min(maxBlockSize, maxSize);
+      // make sure allocSize is big enough for the current value
+      allocSize = std::max(allocSize, keyOffset + actualFieldLen);
+      pTemp = (char *) PR_Malloc(allocSize);
+      NS_ASSERTION(pTemp, "out of memory, can't sort");
+      if (!pTemp)
+      {
+        FreeAll(&ptrs);
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+      pBase = pTemp;
+      ptrs.AppendElement(pTemp); // remember this pointer so we can free it later
+    }
+
+    // now store this entry away in the allocated memory
+    IdKey *info = (IdKey*)pTemp;
+    pPtrBase[numSoFar] = info;
+    info->id = thisKey;
+    info->bits = m_flags[numSoFar];
+    info->dword = longValue;
+    //info->pad = 0;
+    info->folder = folders ? folders->ObjectAt(numSoFar) : m_folder.get();
+
+    memcpy(info->key, keyValue, actualFieldLen);
+    //In order to align memory for systems that require it, such as HP-UX
+    //calculate the correct value to pad the actualFieldLen value
+    const uint32_t align = sizeof(IdKey) - sizeof(IdUint32) - 1;
+    actualFieldLen = (actualFieldLen + align) & ~align;
+
+    pTemp += keyOffset + actualFieldLen;
+    ++numSoFar;
+    PR_Free(keyValue);
+  }
+
+  viewSortInfo qsPrivateData;
+  qsPrivateData.view = this;
+  qsPrivateData.isSecondarySort = false;
+  qsPrivateData.ascendingSort = (sortOrder == nsMsgViewSortOrder::ascending);
+
+  nsCOMPtr <nsIMsgDatabase> dbToUse = m_db;
+
+  if (!dbToUse) // probably search view
+    GetDBForViewIndex(0, getter_AddRefs(dbToUse));
+  qsPrivateData.db = dbToUse;
+  if (dbToUse)
+  {
+    // do the sort
+    switch (fieldType)
+    {
+      case kCollationKey:
+        NS_QuickSort(pPtrBase, numSoFar, sizeof(IdKey*), FnSortIdKey, &qsPrivateData);
+        break;
+      case kU32:
+        NS_QuickSort(pPtrBase, numSoFar, sizeof(IdKey*), FnSortIdUint32, &qsPrivateData);
+        break;
+      default:
+        NS_ERROR("not supposed to get here");
+        break;
+    }
+  }
+
+  // now put the IDs into the array in proper order
+  for (uint32_t i = 0; i < numSoFar; i++)
+  {
+    m_keys[i] = pPtrBase[i]->id;
+    m_flags[i] = pPtrBase[i]->bits;
+
+    if (folders)
+      folders->ReplaceObjectAt(pPtrBase[i]->folder, i);
+  }
+
+  m_sortType = sortType;
+  m_sortOrder = sortOrder;
+
+  // free all the memory we allocated
+  FreeAll(&ptrs);
+
+  m_sortValid = true;
+  //m_db->SetSortInfo(sortType, sortOrder);
+
+  return NS_OK;
+}
+
+void nsMsgDBView::FreeAll(nsTArray<void*> *ptrs)
+{
+  int32_t i;
+  int32_t count = (int32_t) ptrs->Length();
+  if (count == 0)
+    return;
+
+  for (i=(count - 1);i>=0;i--)
+    PR_Free((void *) ptrs->ElementAt(i));
+  ptrs->Clear();
+}
+
+nsMsgViewIndex nsMsgDBView::GetIndexOfFirstDisplayedKeyInThread(
+    nsIMsgThread *threadHdr, bool allowDummy)
+{
+  nsMsgViewIndex  retIndex = nsMsgViewIndex_None;
+  uint32_t        childIndex = 0;
+  // We could speed up the unreadOnly view by starting our search with the first
+  // unread message in the thread. Sometimes, that will be wrong, however, so
+  // let's skip it until we're sure it's necessary.
+  //  (m_viewFlags & nsMsgViewFlagsType::kUnreadOnly)
+  //    ? threadHdr->GetFirstUnreadKey(m_db) : threadHdr->GetChildAt(0);
+  uint32_t numThreadChildren;
+  threadHdr->GetNumChildren(&numThreadChildren);
+  while (retIndex == nsMsgViewIndex_None && childIndex < numThreadChildren)
+  {
+    nsCOMPtr<nsIMsgDBHdr> childHdr;
+    threadHdr->GetChildHdrAt(childIndex++, getter_AddRefs(childHdr));
+    if (childHdr)
+      retIndex = FindHdr(childHdr, 0, allowDummy);
+  }
+  return retIndex;
+}
+
+nsresult nsMsgDBView::GetFirstMessageHdrToDisplayInThread(nsIMsgThread *threadHdr, nsIMsgDBHdr **result)
+{
+  nsresult rv;
+
+  if (m_viewFlags & nsMsgViewFlagsType::kUnreadOnly)
+    rv = threadHdr->GetFirstUnreadChild(result);
+  else
+    rv = threadHdr->GetChildHdrAt(0, result);
+  return rv;
+}
+
+// Find the view index of the thread containing the passed msgKey, if
+// the thread is in the view. MsgIndex is passed in as a shortcut if
+// it turns out the msgKey is the first message in the thread,
+// then we can avoid looking for the msgKey.
+nsMsgViewIndex nsMsgDBView::ThreadIndexOfMsg(nsMsgKey msgKey,
+                                            nsMsgViewIndex msgIndex /* = nsMsgViewIndex_None */,
+                                            int32_t *pThreadCount /* = NULL */,
+                                            uint32_t *pFlags /* = NULL */)
+{
+  if (! (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay))
+    return nsMsgViewIndex_None;
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  nsresult rv = m_db->GetMsgHdrForKey(msgKey, getter_AddRefs(msgHdr));
+  NS_ENSURE_SUCCESS(rv, nsMsgViewIndex_None);
+  return ThreadIndexOfMsgHdr(msgHdr, msgIndex, pThreadCount, pFlags);
+}
+
+nsMsgViewIndex nsMsgDBView::GetThreadIndex(nsMsgViewIndex msgIndex)
+{
+  if (!IsValidIndex(msgIndex))
+    return nsMsgViewIndex_None;
+
+  // scan up looking for level 0 message.
+  while (m_levels[msgIndex] && msgIndex)
+    --msgIndex;
+  return msgIndex;
+}
+
+nsMsgViewIndex
+nsMsgDBView::ThreadIndexOfMsgHdr(nsIMsgDBHdr *msgHdr,
+                                 nsMsgViewIndex msgIndex,
+                                 int32_t *pThreadCount,
+                                 uint32_t *pFlags)
+{
+  nsCOMPtr<nsIMsgThread> threadHdr;
+  nsresult rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(threadHdr));
+  NS_ENSURE_SUCCESS(rv, nsMsgViewIndex_None);
+
+  nsMsgViewIndex retIndex = nsMsgViewIndex_None;
+
+  if (threadHdr != nullptr)
+  {
+    if (msgIndex == nsMsgViewIndex_None)
+      msgIndex = FindHdr(msgHdr, 0, true);
+
+    if (msgIndex == nsMsgViewIndex_None)  // hdr is not in view, need to find by thread
+    {
+      msgIndex = GetIndexOfFirstDisplayedKeyInThread(threadHdr, true);
+      //nsMsgKey    threadKey = (msgIndex == nsMsgViewIndex_None) ? nsMsgKey_None : GetAt(msgIndex);
+      if (pFlags)
+        threadHdr->GetFlags(pFlags);
+    }
+    nsMsgViewIndex startOfThread = msgIndex;
+    while ((int32_t) startOfThread >= 0 && m_levels[startOfThread] != 0)
+      startOfThread--;
+    retIndex = startOfThread;
+    if (pThreadCount)
+    {
+      int32_t numChildren = 0;
+      nsMsgViewIndex threadIndex = startOfThread;
+      do
+      {
+        threadIndex++;
+        numChildren++;
+      }
+      while (threadIndex < m_levels.Length() && m_levels[threadIndex] != 0);
+      *pThreadCount = numChildren;
+    }
+  }
+  return retIndex;
+}
+
+nsMsgKey nsMsgDBView::GetKeyOfFirstMsgInThread(nsMsgKey key)
+{
+  // Just report no key for any failure. This can occur when a
+  // message is deleted from a threaded view
+  nsCOMPtr <nsIMsgThread> pThread;
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  nsresult rv = m_db->GetMsgHdrForKey(key, getter_AddRefs(msgHdr));
+  if (NS_FAILED(rv))
+    return nsMsgKey_None;
+  rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(pThread));
+  if (NS_FAILED(rv))
+    return nsMsgKey_None;
+  nsMsgKey  firstKeyInThread = nsMsgKey_None;
+
+  if (!pThread)
+    return firstKeyInThread;
+
+  // ### dmb UnreadOnly - this is wrong. But didn't seem to matter in 4.x
+  pThread->GetChildKeyAt(0, &firstKeyInThread);
+  return firstKeyInThread;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetKeyAt(nsMsgViewIndex index, nsMsgKey *result)
+{
+  NS_ENSURE_ARG(result);
+  *result = GetAt(index);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetFlagsAt(nsMsgViewIndex aIndex, uint32_t *aResult)
+{
+  NS_ENSURE_ARG(aResult);
+  if (!IsValidIndex(aIndex))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  *aResult = m_flags[aIndex];
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetMsgHdrAt(nsMsgViewIndex aIndex, nsIMsgDBHdr **aResult)
+{
+  NS_ENSURE_ARG(aResult);
+  if (!IsValidIndex(aIndex))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  return GetMsgHdrForViewIndex(aIndex, aResult);
+}
+
+nsMsgViewIndex nsMsgDBView::FindHdr(nsIMsgDBHdr *msgHdr, nsMsgViewIndex startIndex,
+                                    bool allowDummy)
+{
+  nsMsgKey msgKey;
+  msgHdr->GetMessageKey(&msgKey);
+  nsMsgViewIndex viewIndex = m_keys.IndexOf(msgKey, startIndex);
+  if (viewIndex == nsMsgViewIndex_None)
+    return viewIndex;
+  // if we're supposed to allow dummies, and the previous index is a dummy that
+  //  is not elided, then it must be the dummy corresponding to our node and
+  //  we should return that instead.
+  if (allowDummy && viewIndex
+      && (m_flags[viewIndex-1] & MSG_VIEW_FLAG_DUMMY)
+      && !(m_flags[viewIndex-1] & nsMsgMessageFlags::Elided))
+    viewIndex--;
+  // else if we're not allowing dummies, and we found a dummy, look again
+  // one past the dummy.
+  else if (!allowDummy && m_flags[viewIndex] & MSG_VIEW_FLAG_DUMMY)
+    return m_keys.IndexOf(msgKey, viewIndex + 1);
+  return viewIndex;
+}
+
+nsMsgViewIndex nsMsgDBView::FindKey(nsMsgKey key, bool expand)
+{
+  nsMsgViewIndex retIndex = nsMsgViewIndex_None;
+  retIndex = (nsMsgViewIndex) (m_keys.IndexOf(key));
+  // for dummy headers, try to expand if the caller says so. And if the thread is
+  // expanded, ignore the dummy header and return the real header index.
+  if (retIndex != nsMsgViewIndex_None && m_flags[retIndex] & MSG_VIEW_FLAG_DUMMY &&  !(m_flags[retIndex] & nsMsgMessageFlags::Elided))
+    return (nsMsgViewIndex) m_keys.IndexOf(key, retIndex + 1);
+  if (key != nsMsgKey_None && (retIndex == nsMsgViewIndex_None || m_flags[retIndex] & MSG_VIEW_FLAG_DUMMY)
+    && expand && m_db)
+  {
+    nsMsgKey threadKey = GetKeyOfFirstMsgInThread(key);
+    if (threadKey != nsMsgKey_None)
+    {
+      nsMsgViewIndex threadIndex = FindKey(threadKey, false);
+      if (threadIndex != nsMsgViewIndex_None)
+      {
+        uint32_t flags = m_flags[threadIndex];
+        if (((flags & nsMsgMessageFlags::Elided) &&
+             NS_SUCCEEDED(ExpandByIndex(threadIndex, nullptr)))
+            || (flags & MSG_VIEW_FLAG_DUMMY))
+          retIndex = (nsMsgViewIndex) m_keys.IndexOf(key, threadIndex + 1);
+      }
+    }
+  }
+  return retIndex;
+}
+
+nsresult nsMsgDBView::GetThreadCount(nsMsgViewIndex index, uint32_t *pThreadCount)
+{
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  nsresult rv = GetMsgHdrForViewIndex(index, getter_AddRefs(msgHdr));
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr <nsIMsgThread> pThread;
+  rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(pThread));
+  if (NS_SUCCEEDED(rv) && pThread != nullptr)
+    rv = pThread->GetNumChildren(pThreadCount);
+  return rv;
+}
+
+// This counts the number of messages in an expanded thread, given the
+// index of the first message in the thread.
+int32_t nsMsgDBView::CountExpandedThread(nsMsgViewIndex index)
+{
+  int32_t numInThread = 0;
+  nsMsgViewIndex startOfThread = index;
+  while ((int32_t) startOfThread >= 0 && m_levels[startOfThread] != 0)
+    startOfThread--;
+  nsMsgViewIndex threadIndex = startOfThread;
+  do
+  {
+    threadIndex++;
+    numInThread++;
+  }
+  while (threadIndex < m_levels.Length() && m_levels[threadIndex] != 0);
+
+  return numInThread;
+}
+
+// returns the number of lines that would be added (> 0) or removed (< 0)
+// if we were to try to expand/collapse the passed index.
+nsresult nsMsgDBView::ExpansionDelta(nsMsgViewIndex index, int32_t *expansionDelta)
+{
+  uint32_t numChildren;
+  nsresult  rv;
+
+  *expansionDelta = 0;
+  if (index >= ((nsMsgViewIndex) m_keys.Length()))
+    return NS_MSG_MESSAGE_NOT_FOUND;
+  char  flags = m_flags[index];
+
+  if (!(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay))
+    return NS_OK;
+
+  // The client can pass in the key of any message
+  // in a thread and get the expansion delta for the thread.
+
+  if (flags & nsMsgMessageFlags::Elided)
+  {
+    rv = GetThreadCount(index, &numChildren);
+    NS_ENSURE_SUCCESS(rv, rv);
+    *expansionDelta = numChildren - 1;
+  }
+  else
+  {
+    numChildren = CountExpandedThread(index);
+    *expansionDelta = - (int32_t) (numChildren - 1);
+  }
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::ToggleExpansion(nsMsgViewIndex index, uint32_t *numChanged)
+{
+  nsresult rv;
+  NS_ENSURE_ARG(numChanged);
+  *numChanged = 0;
+  nsMsgViewIndex threadIndex = GetThreadIndex(index);
+  if (threadIndex == nsMsgViewIndex_None)
+  {
+    NS_ASSERTION(false, "couldn't find thread");
+    return NS_MSG_MESSAGE_NOT_FOUND;
+  }
+  int32_t  flags = m_flags[threadIndex];
+
+  // if not a thread, or doesn't have children, no expand/collapse
+  // If we add sub-thread expand collapse, this will need to be relaxed
+  if (!(flags & MSG_VIEW_FLAG_ISTHREAD) || !(flags & MSG_VIEW_FLAG_HASCHILDREN))
+    return NS_MSG_MESSAGE_NOT_FOUND;
+  if (flags & nsMsgMessageFlags::Elided)
+    rv = ExpandByIndex(threadIndex, numChanged);
+  else
+    rv = CollapseByIndex(threadIndex, numChanged);
+
+  // if we collaps/uncollapse a thread, this changes the selected URIs
+  SelectionChanged();
+  return rv;
+}
+
+nsresult nsMsgDBView::ExpandAndSelectThread()
+{
+    nsresult rv;
+
+    NS_ASSERTION(mTreeSelection, "no tree selection");
+    if (!mTreeSelection) return NS_ERROR_UNEXPECTED;
+
+    int32_t index;
+    rv = mTreeSelection->GetCurrentIndex(&index);
+    NS_ENSURE_SUCCESS(rv,rv);
+
+    rv = ExpandAndSelectThreadByIndex(index, false);
+    NS_ENSURE_SUCCESS(rv,rv);
+    return NS_OK;
+}
+
+nsresult nsMsgDBView::ExpandAndSelectThreadByIndex(nsMsgViewIndex index, bool augment)
+{
+  nsresult rv;
+
+  nsMsgViewIndex threadIndex;
+  bool inThreadedMode = (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay);
+
+  if (inThreadedMode)
+  {
+    nsCOMPtr<nsIMsgDBHdr> msgHdr;
+    GetMsgHdrForViewIndex(index, getter_AddRefs(msgHdr));
+    threadIndex = ThreadIndexOfMsgHdr(msgHdr, index);
+    if (threadIndex == nsMsgViewIndex_None)
+    {
+      NS_ASSERTION(false, "couldn't find thread");
+      return NS_MSG_MESSAGE_NOT_FOUND;
+    }
+  }
+  else
+  {
+    threadIndex = index;
+  }
+
+  int32_t flags = m_flags[threadIndex];
+  int32_t count = 0;
+
+  if (inThreadedMode && (flags & MSG_VIEW_FLAG_ISTHREAD) && (flags & MSG_VIEW_FLAG_HASCHILDREN))
+  {
+    // if closed, expand this thread.
+    if (flags & nsMsgMessageFlags::Elided)
+    {
+      uint32_t numExpanded;
+      rv = ExpandByIndex(threadIndex, &numExpanded);
+      NS_ENSURE_SUCCESS(rv,rv);
+    }
+
+    // get the number of messages in the expanded thread
+    // so we know how many to select
+    count = CountExpandedThread(threadIndex);
+  }
+  else
+  {
+    count = 1;
+  }
+  NS_ASSERTION(count > 0, "bad count");
+
+  // update the selection
+
+  NS_ASSERTION(mTreeSelection, "no tree selection");
+  if (!mTreeSelection) return NS_ERROR_UNEXPECTED;
+
+  // the count should be 1 or greater. if there was only one message in the thread, we just select it.
+  // if more, we select all of them.
+  mTreeSelection->RangedSelect(threadIndex + count - 1, threadIndex, augment);
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::ExpandAll()
+{
+  if (mTree)
+    mTree->BeginUpdateBatch();
+  for (int32_t i = GetSize() - 1; i >= 0; i--)
+  {
+    uint32_t numExpanded;
+    uint32_t flags = m_flags[i];
+    if (flags & nsMsgMessageFlags::Elided)
+      ExpandByIndex(i, &numExpanded);
+  }
+  if (mTree)
+    mTree->EndUpdateBatch();
+  SelectionChanged();
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetThreadContainingMsgHdr(nsIMsgDBHdr *msgHdr, nsIMsgThread **pThread)
+{
+  return m_db->GetThreadContainingMsgHdr(msgHdr, pThread);
+}
+
+nsresult nsMsgDBView::ExpandByIndex(nsMsgViewIndex index, uint32_t *pNumExpanded)
+{
+  if ((uint32_t) index >= m_keys.Length())
+    return NS_MSG_MESSAGE_NOT_FOUND;
+
+  uint32_t      flags = m_flags[index];
+  uint32_t      numExpanded = 0;
+
+  NS_ASSERTION(flags & nsMsgMessageFlags::Elided, "can't expand an already expanded thread");
+  flags &= ~nsMsgMessageFlags::Elided;
+
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  nsCOMPtr <nsIMsgThread> pThread;
+  nsresult rv = GetThreadContainingIndex(index, getter_AddRefs(pThread));
+  NS_ENSURE_SUCCESS(rv, rv);
+  if (m_viewFlags & nsMsgViewFlagsType::kUnreadOnly)
+  {
+    if (flags & nsMsgMessageFlags::Read)
+      m_levels.AppendElement(0);  // keep top level hdr in thread, even though read.
+    rv = ListUnreadIdsInThread(pThread,  index, &numExpanded);
+  }
+  else
+    rv = ListIdsInThread(pThread,  index, &numExpanded);
+
+  if (numExpanded > 0)
+  {
+    m_flags[index] = flags;
+    NoteChange(index, 1, nsMsgViewNotificationCode::changed);
+  }
+  NoteStartChange(index + 1, numExpanded, nsMsgViewNotificationCode::insertOrDelete);
+  NoteEndChange(index + 1, numExpanded, nsMsgViewNotificationCode::insertOrDelete);
+  if (pNumExpanded != nullptr)
+    *pNumExpanded = numExpanded;
+  return rv;
+}
+
+nsresult nsMsgDBView::CollapseAll()
+{
+  for (uint32_t i = 0; i < GetSize(); i++)
+  {
+    uint32_t numExpanded;
+    uint32_t flags = m_flags[i];
+    if (!(flags & nsMsgMessageFlags::Elided) && (flags & MSG_VIEW_FLAG_HASCHILDREN))
+      CollapseByIndex(i, &numExpanded);
+  }
+  SelectionChanged();
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::CollapseByIndex(nsMsgViewIndex index, uint32_t *pNumCollapsed)
+{
+  nsresult  rv;
+  int32_t  flags = m_flags[index];
+  int32_t  rowDelta = 0;
+
+  if (flags & nsMsgMessageFlags::Elided || !(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) || !(flags & MSG_VIEW_FLAG_HASCHILDREN))
+    return NS_OK;
+
+  if (index > m_keys.Length())
+    return NS_MSG_MESSAGE_NOT_FOUND;
+
+  rv = ExpansionDelta(index, &rowDelta);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  flags |= nsMsgMessageFlags::Elided;
+
+  m_flags[index] = flags;
+  NoteChange(index, 1, nsMsgViewNotificationCode::changed);
+
+  int32_t numRemoved = -rowDelta; // don't count first header in thread
+  if (index + 1 + numRemoved > m_keys.Length())
+  {
+    NS_ERROR("trying to remove too many rows");
+    numRemoved -= (index + 1 + numRemoved) - m_keys.Length();
+    if (numRemoved <= 0)
+      return NS_MSG_MESSAGE_NOT_FOUND;
+  }
+  NoteStartChange(index + 1, rowDelta, nsMsgViewNotificationCode::insertOrDelete);
+  // start at first id after thread.
+  RemoveRows(index + 1, numRemoved);
+  if (pNumCollapsed != nullptr)
+    *pNumCollapsed = numRemoved;
+  NoteEndChange(index + 1, rowDelta, nsMsgViewNotificationCode::insertOrDelete);
+
+  return rv;
+}
+
+nsresult nsMsgDBView::OnNewHeader(nsIMsgDBHdr *newHdr, nsMsgKey aParentKey, bool /*ensureListed*/)
+{
+    nsresult rv = NS_OK;
+    // views can override this behaviour, which is to append to view.
+    // This is the mail behaviour, but threaded views will want
+    // to insert in order...
+    if (newHdr)
+  rv = AddHdr(newHdr);
+    return rv;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetThreadContainingIndex(nsMsgViewIndex index, nsIMsgThread **resultThread)
+{
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  nsresult rv = GetMsgHdrForViewIndex(index, getter_AddRefs(msgHdr));
+  NS_ENSURE_SUCCESS(rv, rv);
+  return GetThreadContainingMsgHdr(msgHdr, resultThread);
+}
+
+nsMsgViewIndex
+nsMsgDBView::GetIndexForThread(nsIMsgDBHdr *msgHdr)
+{
+  // Take advantage of the fact that we're already sorted
+  // and find the insert index via a binary search, though expanded threads
+  // make that tricky.
+
+  nsMsgViewIndex highIndex = m_keys.Length();
+  nsMsgViewIndex lowIndex = 0;
+  IdKeyPtr EntryInfo1, EntryInfo2;
+  EntryInfo1.key = nullptr;
+  EntryInfo2.key = nullptr;
+
+  nsresult rv;
+  uint16_t  maxLen;
+  eFieldType fieldType;
+
+  // Get the custom column handler for the primary sort and pass it first
+  // to GetFieldTypeAndLenForSort to get the fieldType and then either
+  // GetCollationKey or GetLongField.
+  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();
+
+  // The following may leave fieldType undefined.
+  // In this case, we can return highIndex right away since
+  // it is the value returned in the default case of
+  // switch (fieldType) statement below.
+  rv = GetFieldTypeAndLenForSort(m_sortType, &maxLen, &fieldType, colHandler);
+  NS_ENSURE_SUCCESS(rv, highIndex);
+
+  const void *pValue1 = &EntryInfo1, *pValue2 = &EntryInfo2;
+
+  int retStatus = 0;
+  msgHdr->GetMessageKey(&EntryInfo1.id);
+  msgHdr->GetFolder(&EntryInfo1.folder);
+  EntryInfo1.folder->Release();
+
+  viewSortInfo comparisonContext;
+  comparisonContext.view = this;
+  comparisonContext.isSecondarySort = false;
+  comparisonContext.ascendingSort = (m_sortOrder == nsMsgViewSortOrder::ascending);
+  nsCOMPtr <nsIMsgDatabase> hdrDB;
+  EntryInfo1.folder->GetMsgDatabase(getter_AddRefs(hdrDB));
+  comparisonContext.db = hdrDB.get();
+  switch (fieldType)
+  {
+    case kCollationKey:
+      rv = GetCollationKey(msgHdr, m_sortType, &EntryInfo1.key, &EntryInfo1.dword, colHandler);
+      NS_ASSERTION(NS_SUCCEEDED(rv),"failed to create collation key");
+      break;
+    case kU32:
+      if (m_sortType == nsMsgViewSortType::byId)
+        EntryInfo1.dword = EntryInfo1.id;
+      else
+        GetLongField(msgHdr, m_sortType, &EntryInfo1.dword, colHandler);
+      break;
+    default:
+      return highIndex;
+  }
+  while (highIndex > lowIndex)
+  {
+    nsMsgViewIndex tryIndex = (lowIndex + highIndex) / 2;
+    // need to adjust tryIndex if it's not a thread.
+    while (m_levels[tryIndex] && tryIndex)
+      tryIndex--;
+
+    if (tryIndex < lowIndex)
+    {
+      NS_ERROR("try index shouldn't be less than low index");
+      break;
+    }
+    EntryInfo2.id = m_keys[tryIndex];
+    GetFolderForViewIndex(tryIndex, &EntryInfo2.folder);
+    EntryInfo2.folder->Release();
+
+    nsCOMPtr <nsIMsgDBHdr> tryHdr;
+    nsCOMPtr <nsIMsgDatabase> db;
+    // ### this should get the db from the folder...
+    GetDBForViewIndex(tryIndex, getter_AddRefs(db));
+    if (db)
+      rv = db->GetMsgHdrForKey(EntryInfo2.id, getter_AddRefs(tryHdr));
+    if (!tryHdr)
+      break;
+    if (tryHdr == msgHdr)
+    {
+      NS_WARNING("didn't expect header to already be in view");
+      highIndex = tryIndex;
+      break;
+    }
+    if (fieldType == kCollationKey)
+    {
+      PR_FREEIF(EntryInfo2.key);
+      rv = GetCollationKey(tryHdr, m_sortType, &EntryInfo2.key, &EntryInfo2.dword, colHandler);
+      NS_ASSERTION(NS_SUCCEEDED(rv),"failed to create collation key");
+      retStatus = FnSortIdKeyPtr(&pValue1, &pValue2, &comparisonContext);
+    }
+    else if (fieldType == kU32)
+    {
+      if (m_sortType == nsMsgViewSortType::byId)
+        EntryInfo2.dword = EntryInfo2.id;
+      else
+        GetLongField(tryHdr, m_sortType, &EntryInfo2.dword, colHandler);
+      retStatus = FnSortIdUint32(&pValue1, &pValue2, &comparisonContext);
+    }
+    if (retStatus == 0)
+    {
+      highIndex = tryIndex;
+      break;
+    }
+
+    if (retStatus < 0)
+    {
+      highIndex = tryIndex;
+      // we already made sure tryIndex was at a thread at the top of the loop.
+    }
+    else
+    {
+      lowIndex = tryIndex + 1;
+      while (lowIndex < GetSize() && m_levels[lowIndex])
+        lowIndex++;
+    }
+  }
+
+  PR_Free(EntryInfo1.key);
+  PR_Free(EntryInfo2.key);
+  return highIndex;
+}
+
+nsMsgViewIndex nsMsgDBView::GetInsertIndexHelper(nsIMsgDBHdr *msgHdr, nsTArray<nsMsgKey> &keys,
+                                                 nsCOMArray<nsIMsgFolder> *folders,
+                                                 nsMsgViewSortOrderValue sortOrder, nsMsgViewSortTypeValue sortType)
+{
+  nsMsgViewIndex highIndex = keys.Length();
+  nsMsgViewIndex lowIndex = 0;
+  IdKeyPtr EntryInfo1, EntryInfo2;
+  EntryInfo1.key = nullptr;
+  EntryInfo2.key = nullptr;
+
+  nsresult rv;
+  uint16_t  maxLen;
+  eFieldType fieldType;
+
+  // Get the custom column handler for the primary sort and pass it first
+  // to GetFieldTypeAndLenForSort to get the fieldType and then either
+  // GetCollationKey or GetLongField.
+  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();
+
+  // The following may leave fieldType undefined.
+  // In this case, we can return highIndex right away since
+  // it is the value returned in the default case of
+  // switch (fieldType) statement below.
+  rv = GetFieldTypeAndLenForSort(sortType, &maxLen, &fieldType, colHandler);
+  NS_ENSURE_SUCCESS(rv, highIndex);
+
+  const void *pValue1 = &EntryInfo1, *pValue2 = &EntryInfo2;
+
+  int (* comparisonFun) (const void *pItem1, const void *pItem2, void *privateData) = nullptr;
+  int retStatus = 0;
+  msgHdr->GetMessageKey(&EntryInfo1.id);
+  msgHdr->GetFolder(&EntryInfo1.folder);
+  EntryInfo1.folder->Release();
+
+  viewSortInfo comparisonContext;
+  comparisonContext.view = this;
+  comparisonContext.isSecondarySort = false;
+  comparisonContext.ascendingSort = (sortOrder == nsMsgViewSortOrder::ascending);
+  rv = EntryInfo1.folder->GetMsgDatabase(&comparisonContext.db);
+  NS_ENSURE_SUCCESS(rv, highIndex);
+  comparisonContext.db->Release();
+  switch (fieldType)
+  {
+    case kCollationKey:
+      rv = GetCollationKey(msgHdr, sortType, &EntryInfo1.key, &EntryInfo1.dword, colHandler);
+      NS_ASSERTION(NS_SUCCEEDED(rv),"failed to create collation key");
+      comparisonFun = FnSortIdKeyPtr;
+      break;
+    case kU32:
+      if (sortType == nsMsgViewSortType::byId)
+        EntryInfo1.dword = EntryInfo1.id;
+      else
+        GetLongField(msgHdr, sortType, &EntryInfo1.dword, colHandler);
+      comparisonFun = FnSortIdUint32;
+      break;
+    default:
+      return highIndex;
+  }
+  while (highIndex > lowIndex)
+  {
+    nsMsgViewIndex tryIndex = (lowIndex + highIndex - 1) / 2;
+    EntryInfo2.id = keys[tryIndex];
+    EntryInfo2.folder = folders ? folders->ObjectAt(tryIndex) : m_folder.get();
+
+    nsCOMPtr <nsIMsgDBHdr> tryHdr;
+    EntryInfo2.folder->GetMessageHeader(EntryInfo2.id, getter_AddRefs(tryHdr));
+    if (!tryHdr)
+      break;
+    if (fieldType == kCollationKey)
+    {
+      PR_FREEIF(EntryInfo2.key);
+      rv = GetCollationKey(tryHdr, sortType, &EntryInfo2.key, &EntryInfo2.dword, colHandler);
+      NS_ASSERTION(NS_SUCCEEDED(rv),"failed to create collation key");
+    }
+    else if (fieldType == kU32)
+    {
+      if (sortType == nsMsgViewSortType::byId) {
+        EntryInfo2.dword = EntryInfo2.id;
+      }
+      else {
+        GetLongField(tryHdr, sortType, &EntryInfo2.dword, colHandler);
+      }
+    }
+    retStatus = (*comparisonFun)(&pValue1, &pValue2, &comparisonContext);
+    if (retStatus == 0)
+    {
+      highIndex = tryIndex;
+      break;
+    }
+
+    if (retStatus < 0)
+    {
+      highIndex = tryIndex;
+    }
+    else
+    {
+      lowIndex = tryIndex + 1;
+    }
+  }
+
+  PR_Free(EntryInfo1.key);
+  PR_Free(EntryInfo2.key);
+  return highIndex;
+}
+
+nsMsgViewIndex nsMsgDBView::GetInsertIndex(nsIMsgDBHdr *msgHdr)
+{
+  if (!GetSize())
+    return 0;
+
+  if ((m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) != 0
+        && !(m_viewFlags & nsMsgViewFlagsType::kGroupBySort)
+        && m_sortOrder != nsMsgViewSortType::byId)
+    return GetIndexForThread(msgHdr);
+
+  return GetInsertIndexHelper(msgHdr, m_keys, GetFolders(), m_sortOrder, m_sortType);
+}
+
+nsresult  nsMsgDBView::AddHdr(nsIMsgDBHdr *msgHdr, nsMsgViewIndex *resultIndex)
+{
+  uint32_t  flags = 0;
+#ifdef DEBUG_bienvenu
+  NS_ASSERTION(m_keys.Length() == m_flags.Length() && (int) m_keys.Length() == m_levels.Length(), "view arrays out of sync!");
+#endif
+
+  if (resultIndex)
+    *resultIndex = nsMsgViewIndex_None;
+
+  if (!GetShowingIgnored())
+  {
+    nsCOMPtr <nsIMsgThread> thread;
+    GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(thread));
+    if (thread)
+    {
+      thread->GetFlags(&flags);
+      if (flags & nsMsgMessageFlags::Ignored)
+        return NS_OK;
+    }
+
+    bool ignored;
+    msgHdr->GetIsKilled(&ignored);
+    if (ignored)
+       return NS_OK;
+  }
+
+  nsMsgKey msgKey, threadId;
+  nsMsgKey threadParent;
+  msgHdr->GetMessageKey(&msgKey);
+  msgHdr->GetThreadId(&threadId);
+  msgHdr->GetThreadParent(&threadParent);
+
+  msgHdr->GetFlags(&flags);
+  // ### this isn't quite right, is it? Should be checking that our thread parent key is none?
+  if (threadParent == nsMsgKey_None)
+    flags |= MSG_VIEW_FLAG_ISTHREAD;
+  nsMsgViewIndex insertIndex = GetInsertIndex(msgHdr);
+  if (insertIndex == nsMsgViewIndex_None)
+  {
+    // if unreadonly, level is 0 because we must be the only msg in the thread.
+    int32_t levelToAdd = 0;
+
+    if (m_sortOrder == nsMsgViewSortOrder::ascending)
+    {
+      InsertMsgHdrAt(GetSize(), msgHdr, msgKey, flags, levelToAdd);
+      if (resultIndex)
+        *resultIndex = GetSize() - 1;
+
+      // the call to NoteChange() has to happen after we add the key
+      // as NoteChange() will call RowCountChanged() which will call our GetRowCount()
+      NoteChange(GetSize() - 1, 1, nsMsgViewNotificationCode::insertOrDelete);
+    }
+    else
+    {
+      InsertMsgHdrAt(0, msgHdr, msgKey, flags, levelToAdd);
+      if (resultIndex)
+        *resultIndex = 0;
+
+      // the call to NoteChange() has to happen after we insert the key
+      // as NoteChange() will call RowCountChanged() which will call our GetRowCount()
+      NoteChange(0, 1, nsMsgViewNotificationCode::insertOrDelete);
+    }
+    m_sortValid = false;
+  }
+  else
+  {
+    InsertMsgHdrAt(insertIndex, msgHdr, msgKey, flags, 0);
+    if (resultIndex)
+      *resultIndex = insertIndex;
+    // the call to NoteChange() has to happen after we add the key
+    // as NoteChange() will call RowCountChanged() which will call our GetRowCount()
+    NoteChange(insertIndex, 1, nsMsgViewNotificationCode::insertOrDelete);
+  }
+  OnHeaderAddedOrDeleted();
+  return NS_OK;
+}
+
+bool nsMsgDBView::WantsThisThread(nsIMsgThread * /*threadHdr*/)
+{
+  return true; // default is to want all threads.
+}
+
+nsMsgViewIndex nsMsgDBView::FindParentInThread(nsMsgKey parentKey, nsMsgViewIndex startOfThreadViewIndex)
+{
+  nsCOMPtr<nsIMsgDBHdr> msgHdr;
+  while (parentKey != nsMsgKey_None)
+  {
+    nsMsgViewIndex parentIndex = m_keys.IndexOf(parentKey, startOfThreadViewIndex);
+    if (parentIndex != nsMsgViewIndex_None)
+      return parentIndex;
+
+    if (NS_FAILED(m_db->GetMsgHdrForKey(parentKey, getter_AddRefs(msgHdr))))
+      break;
+
+    msgHdr->GetThreadParent(&parentKey);
+  }
+
+  return startOfThreadViewIndex;
+}
+
+nsresult nsMsgDBView::ListIdsInThreadOrder(nsIMsgThread *threadHdr, nsMsgKey parentKey,
+                                           uint32_t level, nsMsgViewIndex *viewIndex,
+                                           uint32_t *pNumListed)
+{
+  nsresult rv = NS_OK;
+  nsCOMPtr <nsISimpleEnumerator> msgEnumerator;
+  threadHdr->EnumerateMessages(parentKey, getter_AddRefs(msgEnumerator));
+  uint32_t numChildren;
+  (void) threadHdr->GetNumChildren(&numChildren);
+  NS_ASSERTION(numChildren, "Empty thread in view/db");
+  if (!numChildren)
+    return NS_OK;  // bogus, but harmless.
+
+  numChildren--; // account for the existing thread root
+
+  // skip the first one.
+  bool hasMore;
+  nsCOMPtr <nsISupports> supports;
+  nsCOMPtr <nsIMsgDBHdr> msgHdr;
+  while (NS_SUCCEEDED(rv) && NS_SUCCEEDED(rv = msgEnumerator->HasMoreElements(&hasMore)) && hasMore)
+  {
+    rv = msgEnumerator->GetNext(getter_AddRefs(supports));
+    if (NS_SUCCEEDED(rv) && supports)
+    {
+      if (*pNumListed == numChildren)
+      {
+        NS_NOTREACHED("thread corrupt in db");
+        // if we've listed more messages than are in the thread, then the db
+        // is corrupt, and we should invalidate it.
+        // we'll use this rv to indicate there's something wrong with the db
+        // though for now it probably won't get paid attention to.
+        m_db->SetSummaryValid(false);
+        rv = NS_MSG_ERROR_FOLDER_SUMMARY_OUT_OF_DATE;
+        break;
+      }
+
+      msgHdr = do_QueryInterface(supports);
+      if (!(m_viewFlags & nsMsgViewFlagsType::kShowIgnored))
+      {
+        bool ignored;
+        msgHdr->GetIsKilled(&ignored);
+        // We are not going to process subthreads, horribly invalidating the
+        // numChildren characteristic
+        if (ignored)
+          continue;
+      }
+
+      nsMsgKey msgKey;
+      uint32_t msgFlags, newFlags;
+      msgHdr->GetMessageKey(&msgKey);
+      msgHdr->GetFlags(&msgFlags);
+      AdjustReadFlag(msgHdr, &msgFlags);
+      SetMsgHdrAt(msgHdr, *viewIndex, msgKey, msgFlags & ~MSG_VIEW_FLAGS, level);
+      // turn off thread or elided bit if they got turned on (maybe from new only view?)
+      msgHdr->AndFlags(~(MSG_VIEW_FLAG_ISTHREAD | nsMsgMessageFlags::Elided), &newFlags);
+      (*pNumListed)++;
+      (*viewIndex)++;
+      rv = ListIdsInThreadOrder(threadHdr, msgKey, level + 1, viewIndex, pNumListed);
+    }
+  }
+  return rv; // we don't want to return the rv from the enumerator when it reaches the end, do we?
+}
+
+bool nsMsgDBView::InsertEmptyRows(nsMsgViewIndex viewIndex, int32_t numRows)
+{
+  return m_keys.InsertElementsAt(viewIndex, numRows, 0) &&
+         m_flags.InsertElementsAt(viewIndex, numRows, 0) &&
+         m_levels.InsertElementsAt(viewIndex, numRows, 1);
+}
+
+void nsMsgDBView::RemoveRows(nsMsgViewIndex viewIndex, int32_t numRows)
+{
+  m_keys.RemoveElementsAt(viewIndex, numRows);
+  m_flags.RemoveElementsAt(viewIndex, numRows);
+  m_levels.RemoveElementsAt(viewIndex, numRows);
+}
+
+NS_IMETHODIMP nsMsgDBView::InsertTreeRows(nsMsgViewIndex aIndex,
+                                          uint32_t aNumRows,
+                                          nsMsgKey aKey,
+                                          nsMsgViewFlagsTypeValue aFlags,
+                                          uint32_t aLevel,
+                                          nsIMsgFolder *aFolder)
+{
+  if (GetSize() < aIndex)
+    return NS_ERROR_UNEXPECTED;
+
+  nsCOMArray<nsIMsgFolder> *folders = GetFolders();
+  if (folders)
+  {
+    // In a search/xfvf view only, a folder is required.
+    NS_ENSURE_ARG_POINTER(aFolder);
+    for (size_t i = 0; i < aNumRows; i++)
+      // Insert into m_folders.
+      if (!folders->InsertObjectAt(aFolder, aIndex + i))
+        return NS_ERROR_UNEXPECTED;
+  }
+
+  if (m_keys.InsertElementsAt(aIndex, aNumRows, aKey) &&
+      m_flags.InsertElementsAt(aIndex, aNumRows, aFlags) &&
+      m_levels.InsertElementsAt(aIndex, aNumRows, aLevel))
+    return NS_OK;
+
+  return NS_ERROR_UNEXPECTED;
+}
+
+NS_IMETHODIMP nsMsgDBView::RemoveTreeRows(nsMsgViewIndex aIndex,
+                                          uint32_t aNumRows)
+{
+  // Prevent a crash if attempting to remove rows which don't exist.
+  if (GetSize() < aIndex + aNumRows)
+    return NS_ERROR_UNEXPECTED;
+
+  nsMsgDBView::RemoveRows(aIndex, aNumRows);
+
+  nsCOMArray<nsIMsgFolder> *folders = GetFolders();
+  if (folders)
+    // In a search/xfvf view only, remove from m_folders.
+    if (!folders->RemoveObjectsAt(aIndex, aNumRows))
+      return NS_ERROR_UNEXPECTED;
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::ListIdsInThread(nsIMsgThread *threadHdr, nsMsgViewIndex startOfThreadViewIndex, uint32_t *pNumListed)
+{
+  NS_ENSURE_ARG(threadHdr);
+  // these children ids should be in thread order.
+  nsresult rv = NS_OK;
+  uint32_t i;
+  nsMsgViewIndex viewIndex = startOfThreadViewIndex + 1;
+  *pNumListed = 0;
+
+  uint32_t numChildren;
+  threadHdr->GetNumChildren(&numChildren);
+  NS_ASSERTION(numChildren, "Empty thread in view/db");
+  if (!numChildren)
+    return NS_OK;
+
+  numChildren--; // account for the existing thread root
+  if (!InsertEmptyRows(viewIndex, numChildren))
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  // ### need to rework this when we implemented threading in group views.
+  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay && ! (m_viewFlags & nsMsgViewFlagsType::kGroupBySort))
+  {
+    nsMsgKey parentKey = m_keys[startOfThreadViewIndex];
+    // If the thread is bigger than the hdr cache, expanding the thread
+    // can be slow. Increasing the hdr cache size will help a fair amount.
+    uint32_t hdrCacheSize;
+    m_db->GetMsgHdrCacheSize(&hdrCacheSize);
+    if (numChildren > hdrCacheSize)
+      m_db->SetMsgHdrCacheSize(numChildren);
+    // If this fails, *pNumListed will be 0, and we'll fall back to just
+    // enumerating the messages in the thread below.
+    rv = ListIdsInThreadOrder(threadHdr, parentKey, 1, &viewIndex, pNumListed);
+    if (numChildren > hdrCacheSize)
+      m_db->SetMsgHdrCacheSize(hdrCacheSize);
+  }
+  if (! *pNumListed)
+  {
+    uint32_t ignoredHeaders = 0;
+    // if we're not threaded, just list em out in db order
+    for (i = 1; i <= numChildren; i++)
+    {
+      nsCOMPtr <nsIMsgDBHdr> msgHdr;
+      threadHdr->GetChildHdrAt(i, getter_AddRefs(msgHdr));
+
+      if (msgHdr != nullptr)
+      {
+        if (!(m_viewFlags & nsMsgViewFlagsType::kShowIgnored))
+        {
+          bool killed;
+          msgHdr->GetIsKilled(&killed);
+          if (killed)
+          {
+            ignoredHeaders++;
+            continue;
+          }
+        }
+
+        nsMsgKey msgKey;
+        uint32_t msgFlags, newFlags;
+        msgHdr->GetMessageKey(&msgKey);
+        msgHdr->GetFlags(&msgFlags);
+        AdjustReadFlag(msgHdr, &msgFlags);
+        SetMsgHdrAt(msgHdr, viewIndex, msgKey, msgFlags & ~MSG_VIEW_FLAGS, 1);
+        // here, we're either flat, or we're grouped - in either case, level is 1
+        // turn off thread or elided bit if they got turned on (maybe from new only view?)
+        if (i > 0)
+          msgHdr->AndFlags(~(MSG_VIEW_FLAG_ISTHREAD | nsMsgMessageFlags::Elided), &newFlags);
+        (*pNumListed)++;
+        viewIndex++;
+      }
+    }
+    if (ignoredHeaders + *pNumListed < numChildren)
+    {
+      NS_NOTREACHED("thread corrupt in db");
+      // if we've listed fewer messages than are in the thread, then the db
+      // is corrupt, and we should invalidate it.
+      // we'll use this rv to indicate there's something wrong with the db
+      // though for now it probably won't get paid attention to.
+      m_db->SetSummaryValid(false);
+      rv = NS_MSG_ERROR_FOLDER_SUMMARY_OUT_OF_DATE;
+    }
+  }
+
+  // We may have added too many elements (i.e., subthreads were cut)
+  // ### fix for cross folder view case.
+  if (*pNumListed < numChildren)
+    RemoveRows(viewIndex, numChildren - *pNumListed);
+  return rv;
+}
+
+int32_t nsMsgDBView::FindLevelInThread(nsIMsgDBHdr *msgHdr, nsMsgViewIndex startOfThread, nsMsgViewIndex viewIndex)
+{
+  nsCOMPtr <nsIMsgDBHdr> curMsgHdr = msgHdr;
+  nsMsgKey msgKey;
+  msgHdr->GetMessageKey(&msgKey);
+
+  // look through the ancestors of the passed in msgHdr in turn, looking for them in the view, up to the start of
+  // the thread. If we find an ancestor, then our level is one greater than the level of the ancestor.
+  while (curMsgHdr)
+  {
+    nsMsgKey parentKey;
+    curMsgHdr->GetThreadParent(&parentKey);
+    if (parentKey == nsMsgKey_None)
+      break;
+
+    // scan up to find view index of ancestor, if any
+    for (nsMsgViewIndex indexToTry = viewIndex; indexToTry && indexToTry-- >= startOfThread;)
+    {
+      if (m_keys[indexToTry] == parentKey)
+        return m_levels[indexToTry] + 1;
+    }
+
+    // if msgHdr's key is its parentKey, we'll loop forever, so protect
+    // against that corruption.
+    if (msgKey == parentKey || NS_FAILED(m_db->GetMsgHdrForKey(parentKey, getter_AddRefs(curMsgHdr))))
+    {
+      NS_ERROR("msgKey == parentKey, or GetMsgHdrForKey failed, this used to be an infinte loop condition");
+      curMsgHdr = nullptr;
+    }
+    else
+    {
+      // need to update msgKey so the check for a msgHdr with matching
+      // key+parentKey will work after first time through loop
+      curMsgHdr->GetMessageKey(&msgKey);
+    }
+  }
+  return 1;
+}
+
+// ### Can this be combined with GetIndexForThread??
+nsMsgViewIndex
+nsMsgDBView::GetThreadRootIndex(nsIMsgDBHdr *msgHdr)
+{
+  if (!msgHdr)
+  {
+    NS_WARNING("null msgHdr parameter");
+    return nsMsgViewIndex_None;
+  }
+
+  // Take advantage of the fact that we're already sorted
+  // and find the thread root via a binary search.
+
+  nsMsgViewIndex highIndex = m_keys.Length();
+  nsMsgViewIndex lowIndex = 0;
+  IdKeyPtr EntryInfo1, EntryInfo2;
+  EntryInfo1.key = nullptr;
+  EntryInfo2.key = nullptr;
+
+  nsresult rv;
+  uint16_t maxLen;
+  eFieldType fieldType;
+
+  // Get the custom column handler for the primary sort and pass it first
+  // to GetFieldTypeAndLenForSort to get the fieldType and then either
+  // GetCollationKey or GetLongField.
+  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();
+
+  // The following may leave fieldType undefined.
+  // In this case, we can return highIndex right away since
+  // it is the value returned in the default case of
+  // switch (fieldType) statement below.
+  rv = GetFieldTypeAndLenForSort(m_sortType, &maxLen, &fieldType, colHandler);
+  NS_ENSURE_SUCCESS(rv, highIndex);
+
+  const void *pValue1 = &EntryInfo1, *pValue2 = &EntryInfo2;
+
+  int retStatus = 0;
+  msgHdr->GetMessageKey(&EntryInfo1.id);
+  msgHdr->GetFolder(&EntryInfo1.folder);
+  EntryInfo1.folder->Release();
+
+  viewSortInfo comparisonContext;
+  comparisonContext.view = this;
+  comparisonContext.isSecondarySort = false;
+  comparisonContext.ascendingSort = (m_sortOrder == nsMsgViewSortOrder::ascending);
+  nsCOMPtr<nsIMsgDatabase> hdrDB;
+  EntryInfo1.folder->GetMsgDatabase(getter_AddRefs(hdrDB));
+  comparisonContext.db = hdrDB.get();
+  switch (fieldType)
+  {
+    case kCollationKey:
+      rv = GetCollationKey(msgHdr, m_sortType, &EntryInfo1.key, &EntryInfo1.dword, colHandler);
+      NS_ASSERTION(NS_SUCCEEDED(rv),"failed to create collation key");
+      break;
+    case kU32:
+      if (m_sortType == nsMsgViewSortType::byId)
+        EntryInfo1.dword = EntryInfo1.id;
+      else
+        GetLongField(msgHdr, m_sortType, &EntryInfo1.dword, colHandler);
+      break;
+    default:
+      return highIndex;
+  }
+  while (highIndex > lowIndex)
+  {
+    nsMsgViewIndex tryIndex = (lowIndex + highIndex) / 2;
+    // need to adjust tryIndex if it's not a thread.
+    while (m_levels[tryIndex] && tryIndex)
+      tryIndex--;
+
+    if (tryIndex < lowIndex)
+    {
+      NS_ERROR("try index shouldn't be less than low index");
+      break;
+    }
+    EntryInfo2.id = m_keys[tryIndex];
+    GetFolderForViewIndex(tryIndex, &EntryInfo2.folder);
+    EntryInfo2.folder->Release();
+
+    nsCOMPtr<nsIMsgDBHdr> tryHdr;
+    nsCOMPtr<nsIMsgDatabase> db;
+    // ### this should get the db from the folder...
+    GetDBForViewIndex(tryIndex, getter_AddRefs(db));
+    if (db)
+      rv = db->GetMsgHdrForKey(EntryInfo2.id, getter_AddRefs(tryHdr));
+    if (!tryHdr)
+      break;
+    if (tryHdr == msgHdr)
+    {
+      highIndex = tryIndex;
+      break;
+    }
+    if (fieldType == kCollationKey)
+    {
+      PR_FREEIF(EntryInfo2.key);
+      rv = GetCollationKey(tryHdr, m_sortType, &EntryInfo2.key, &EntryInfo2.dword, colHandler);
+      NS_ASSERTION(NS_SUCCEEDED(rv),"failed to create collation key");
+      retStatus = FnSortIdKeyPtr(&pValue1, &pValue2, &comparisonContext);
+    }
+    else if (fieldType == kU32)
+    {
+      if (m_sortType == nsMsgViewSortType::byId)
+        EntryInfo2.dword = EntryInfo2.id;
+      else
+        GetLongField(tryHdr, m_sortType, &EntryInfo2.dword, colHandler);
+      retStatus = FnSortIdUint32(&pValue1, &pValue2, &comparisonContext);
+    }
+    if (retStatus == 0)
+    {
+      highIndex = tryIndex;
+      break;
+    }
+
+    if (retStatus < 0)
+    {
+      highIndex = tryIndex;
+      // we already made sure tryIndex was at a thread at the top of the loop.
+    }
+    else
+    {
+      lowIndex = tryIndex + 1;
+      while (lowIndex < GetSize() && m_levels[lowIndex])
+        lowIndex++;
+    }
+  }
+
+  nsCOMPtr<nsIMsgDBHdr> resultHdr;
+  GetMsgHdrForViewIndex(highIndex, getter_AddRefs(resultHdr));
+
+  if (resultHdr != msgHdr)
+  {
+    NS_WARNING("didn't find hdr");
+    highIndex = FindHdr(msgHdr);
+#ifdef DEBUG_David_Bienvenu
+    if (highIndex != nsMsgViewIndex_None)
+    {
+      NS_WARNING("but find hdr did");
+      printf("level of found hdr = %d\n", m_levels[highIndex]);
+      ValidateSort();
+    }
+#endif
+    return highIndex;
+  }
+  PR_Free(EntryInfo1.key);
+  PR_Free(EntryInfo2.key);
+  return msgHdr == resultHdr ? highIndex : nsMsgViewIndex_None;
+}
+
+#ifdef DEBUG_David_Bienvenu
+
+void nsMsgDBView::InitEntryInfoForIndex(nsMsgViewIndex i, IdKeyPtr &EntryInfo)
+{
+  EntryInfo.key = nullptr;
+
+  nsresult rv;
+  uint16_t maxLen;
+  eFieldType fieldType;
+
+  // Get the custom column handler for the primary sort and pass it first
+  // to GetFieldTypeAndLenForSort to get the fieldType and then either
+  // GetCollationKey or GetLongField.
+  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();
+
+  // The following may leave fieldType undefined.
+  rv = GetFieldTypeAndLenForSort(m_sortType, &maxLen, &fieldType, colHandler);
+  NS_ASSERTION(NS_SUCCEEDED(rv),"failed to obtain fieldType");
+
+  nsCOMPtr<nsIMsgDBHdr> msgHdr;
+  GetMsgHdrForViewIndex(i, getter_AddRefs(msgHdr));
+
+  msgHdr->GetMessageKey(&EntryInfo.id);
+  msgHdr->GetFolder(&EntryInfo.folder);
+  EntryInfo.folder->Release();
+
+  nsCOMPtr<nsIMsgDatabase> hdrDB;
+  EntryInfo.folder->GetMsgDatabase(getter_AddRefs(hdrDB));
+  switch (fieldType)
+  {
+    case kCollationKey:
+      PR_FREEIF(EntryInfo.key);
+      rv = GetCollationKey(msgHdr, m_sortType, &EntryInfo.key, &EntryInfo.dword, colHandler);
+      NS_ASSERTION(NS_SUCCEEDED(rv),"failed to create collation key");
+      break;
+    case kU32:
+      if (m_sortType == nsMsgViewSortType::byId)
+        EntryInfo.dword = EntryInfo.id;
+      else
+        GetLongField(msgHdr, m_sortType, &EntryInfo.dword, colHandler);
+      break;
+    default:
+      NS_ERROR("invalid field type");
+  }
+}
+
+void nsMsgDBView::ValidateSort()
+{
+  IdKeyPtr EntryInfo1, EntryInfo2;
+  nsCOMPtr<nsIMsgDBHdr> hdr1, hdr2;
+
+  uint16_t  maxLen;
+  eFieldType fieldType;
+
+  // Get the custom column handler for the primary sort and pass it first
+  // to GetFieldTypeAndLenForSort to get the fieldType and then either
+  // GetCollationKey or GetLongField.
+  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();
+
+  // It is not entirely clear what we should do since,
+  // if fieldType is not available, there is no way to know
+  // how to compare the field to check for sorting.
+  // So we bomb out here. It is OK since this is debug code
+  // inside  #ifdef DEBUG_David_Bienvenu
+  rv = GetFieldTypeAndLenForSort(m_sortType, &maxLen, &fieldType, colHandler);
+  NS_ASSERTION(NS_SUCCEEDED(rv),"failed to obtain fieldType");
+
+  viewSortInfo comparisonContext;
+  comparisonContext.view = this;
+  comparisonContext.isSecondarySort = false;
+  comparisonContext.ascendingSort = (m_sortOrder == nsMsgViewSortOrder::ascending);
+  nsCOMPtr<nsIMsgDatabase> db;
+  GetDBForViewIndex(0, getter_AddRefs(db));
+  // this is only for comparing collation keys - it could be any db.
+  comparisonContext.db = db.get();
+
+  for (nsMsgViewIndex i = 0; i < m_keys.Length();)
+  {
+    // ignore non threads
+    if (m_levels[i])
+    {
+      i++;
+      continue;
+    }
+
+    // find next header.
+    nsMsgViewIndex j = i + 1;
+    while (j < m_keys.Length() && m_levels[j])
+      j++;
+    if (j == m_keys.Length())
+      break;
+
+    InitEntryInfoForIndex(i, EntryInfo1);
+    InitEntryInfoForIndex(j, EntryInfo2);
+    const void *pValue1 = &EntryInfo1, *pValue2 = &EntryInfo2;
+    int retStatus = 0;
+    if (fieldType == kCollationKey)
+      retStatus = FnSortIdKeyPtr(&pValue1, &pValue2, &comparisonContext);
+    else if (fieldType == kU32)
+      retStatus = FnSortIdUint32(&pValue1, &pValue2, &comparisonContext);
+
+    if (retStatus && (retStatus < 0) == (m_sortOrder == nsMsgViewSortOrder::ascending))
+    {
+      NS_ERROR("view not sorted correctly");
+      break;
+    }
+    // j is the new i.
+    i = j;
+  }
+}
+
+#endif
+
+nsresult nsMsgDBView::ListUnreadIdsInThread(nsIMsgThread *threadHdr, nsMsgViewIndex startOfThreadViewIndex, uint32_t *pNumListed)
+{
+  NS_ENSURE_ARG(threadHdr);
+  // these children ids should be in thread order.
+  nsMsgViewIndex viewIndex = startOfThreadViewIndex + 1;
+  *pNumListed = 0;
+  nsMsgKey topLevelMsgKey = m_keys[startOfThreadViewIndex];
+
+  uint32_t numChildren;
+  threadHdr->GetNumChildren(&numChildren);
+  uint32_t i;
+  for (i = 0; i < numChildren; i++)
+  {
+    nsCOMPtr <nsIMsgDBHdr> msgHdr;
+    threadHdr->GetChildHdrAt(i, getter_AddRefs(msgHdr));
+    if (msgHdr != nullptr)
+    {
+      if (!(m_viewFlags & nsMsgViewFlagsType::kShowIgnored))
+      {
+        bool killed;
+        msgHdr->GetIsKilled(&killed);
+        if (killed)
+          continue;
+      }
+
+      nsMsgKey msgKey;
+      uint32_t msgFlags;
+      msgHdr->GetMessageKey(&msgKey);
+      msgHdr->GetFlags(&msgFlags);
+      bool isRead = AdjustReadFlag(msgHdr, &msgFlags);
+      if (!isRead)
+      {
+        // just make sure flag is right in db.
+        m_db->MarkHdrRead(msgHdr, false, nullptr);
+        if (msgKey != topLevelMsgKey)
+        {
+          InsertMsgHdrAt(viewIndex, msgHdr, msgKey, msgFlags,
+                FindLevelInThread(msgHdr, startOfThreadViewIndex, viewIndex));
+          viewIndex++;
+          (*pNumListed)++;
+        }
+      }
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::OnHdrFlagsChanged(nsIMsgDBHdr *aHdrChanged, uint32_t aOldFlags,
+                                       uint32_t aNewFlags, nsIDBChangeListener *aInstigator)
+{
+  // if we're not the instigator, update flags if this key is in our view
+  if (aInstigator != this)
+  {
+    NS_ENSURE_ARG_POINTER(aHdrChanged);
+    nsMsgKey msgKey;
+    aHdrChanged->GetMessageKey(&msgKey);
+    nsMsgViewIndex index = FindHdr(aHdrChanged);
+    if (index != nsMsgViewIndex_None)
+    {
+      uint32_t viewOnlyFlags = m_flags[index] & (MSG_VIEW_FLAGS | nsMsgMessageFlags::Elided);
+
+      // ### what about saving the old view only flags, like IsThread and HasChildren?
+      // I think we'll want to save those away.
+      m_flags[index] = aNewFlags | viewOnlyFlags;
+      // tell the view the extra flag changed, so it can
+      // update the previous view, if any.
+      OnExtraFlagChanged(index, aNewFlags);
+      NoteChange(index, 1, nsMsgViewNotificationCode::changed);
+    }
+
+    uint32_t deltaFlags = (aOldFlags ^ aNewFlags);
+    if (deltaFlags & (nsMsgMessageFlags::Read | nsMsgMessageFlags::New))
+    {
+      nsMsgViewIndex threadIndex =
+            ThreadIndexOfMsgHdr(aHdrChanged, index, nullptr, nullptr);
+      // may need to fix thread counts
+      if (threadIndex != nsMsgViewIndex_None && threadIndex != index)
+        NoteChange(threadIndex, 1, nsMsgViewNotificationCode::changed);
+    }
+ }
+  // don't need to propagate notifications, right?
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::OnHdrDeleted(nsIMsgDBHdr *aHdrChanged,
+                                        nsMsgKey aParentKey,
+                                        int32_t aFlags,
+                                        nsIDBChangeListener *aInstigator)
+{
+  nsMsgViewIndex deletedIndex = FindHdr(aHdrChanged);
+  if (IsValidIndex(deletedIndex))
+  {
+    // Check if this message is currently selected. If it is, tell the frontend
+    // to be prepared for a delete.
+    if (mTreeSelection && mCommandUpdater)
+    {
+      bool isMsgSelected = false;
+      mTreeSelection->IsSelected(deletedIndex, &isMsgSelected);
+      if (isMsgSelected)
+        mCommandUpdater->UpdateNextMessageAfterDelete();
+    }
+
+    RemoveByIndex(deletedIndex);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::OnHdrAdded(nsIMsgDBHdr *aHdrChanged, nsMsgKey aParentKey, int32_t aFlags,
+                          nsIDBChangeListener *aInstigator)
+{
+  return OnNewHeader(aHdrChanged, aParentKey, false);
+  // probably also want to pass that parent key in, since we went to the trouble
+  // of figuring out what it is.
+}
+
+NS_IMETHODIMP
+nsMsgDBView::OnHdrPropertyChanged(nsIMsgDBHdr *aHdrToChange, bool aPreChange, uint32_t *aStatus,
+                                 nsIDBChangeListener * aInstigator)
+{
+  if (aPreChange)
+    return NS_OK;
+
+  if (aHdrToChange)
+  {
+    nsMsgViewIndex index = FindHdr(aHdrToChange);
+    if (index != nsMsgViewIndex_None)
+      NoteChange(index, 1, nsMsgViewNotificationCode::changed);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::OnParentChanged (nsMsgKey aKeyChanged, nsMsgKey oldParent, nsMsgKey newParent, nsIDBChangeListener *aInstigator)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::OnAnnouncerGoingAway(nsIDBChangeAnnouncer *instigator)
+{
+  if (m_db)
+  {
+    m_db->RemoveListener(this);
+    m_db = nullptr;
+  }
+
+  int32_t saveSize = GetSize();
+  ClearHdrCache();
+
+  // this is important, because the tree will ask us for our
+  // row count, which get determine from the number of keys.
+  m_keys.Clear();
+  // be consistent
+  m_flags.Clear();
+  m_levels.Clear();
+
+  // tell the tree all the rows have gone away
+  if (mTree)
+    mTree->RowCountChanged(0, -saveSize);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::OnEvent(nsIMsgDatabase *aDB, const char *aEvent)
+{
+  if (!strcmp(aEvent, "DBOpened"))
+    m_db = aDB;
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP nsMsgDBView::OnReadChanged(nsIDBChangeListener *aInstigator)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::OnJunkScoreChanged(nsIDBChangeListener *aInstigator)
+{
+  return NS_OK;
+}
+
+void nsMsgDBView::ClearHdrCache()
+{
+  m_cachedHdr = nullptr;
+  m_cachedMsgKey = nsMsgKey_None;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetSuppressChangeNotifications(bool aSuppressChangeNotifications)
+{
+  mSuppressChangeNotification = aSuppressChangeNotifications;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSuppressChangeNotifications(bool * aSuppressChangeNotifications)
+{
+  NS_ENSURE_ARG_POINTER(aSuppressChangeNotifications);
+  *aSuppressChangeNotifications = mSuppressChangeNotification;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::NoteChange(nsMsgViewIndex firstLineChanged,
+                                      int32_t numChanged,
+                                      nsMsgViewNotificationCodeValue changeType)
+{
+  if (mTree && !mSuppressChangeNotification)
+  {
+    switch (changeType)
+    {
+    case nsMsgViewNotificationCode::changed:
+      mTree->InvalidateRange(firstLineChanged, firstLineChanged + numChanged - 1);
+      break;
+    case nsMsgViewNotificationCode::insertOrDelete:
+      if (numChanged < 0)
+        mRemovingRow = true;
+      // the caller needs to have adjusted m_keys before getting here, since
+      // RowCountChanged() will call our GetRowCount()
+      mTree->RowCountChanged(firstLineChanged, numChanged);
+      mRemovingRow = false;
+      MOZ_FALLTHROUGH;
+    case nsMsgViewNotificationCode::all:
+      ClearHdrCache();
+      break;
+    }
+  }
+  return NS_OK;
+}
+
+void nsMsgDBView::NoteStartChange(nsMsgViewIndex firstlineChanged, int32_t numChanged,
+                                  nsMsgViewNotificationCodeValue changeType)
+{
+}
+void nsMsgDBView::NoteEndChange(nsMsgViewIndex firstlineChanged, int32_t numChanged,
+                                nsMsgViewNotificationCodeValue changeType)
+{
+  // send the notification now.
+  NoteChange(firstlineChanged, numChanged, changeType);
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSortOrder(nsMsgViewSortOrderValue *aSortOrder)
+{
+    NS_ENSURE_ARG_POINTER(aSortOrder);
+    *aSortOrder = m_sortOrder;
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSortType(nsMsgViewSortTypeValue *aSortType)
+{
+    NS_ENSURE_ARG_POINTER(aSortType);
+    *aSortType = m_sortType;
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetSortType(nsMsgViewSortTypeValue aSortType)
+{
+    m_sortType = aSortType;
+    return NS_OK;
+}
+
+
+NS_IMETHODIMP nsMsgDBView::GetViewType(nsMsgViewTypeValue *aViewType)
+{
+    NS_ERROR("you should be overriding this");
+    return NS_ERROR_UNEXPECTED;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSecondarySortOrder(nsMsgViewSortOrderValue *aSortOrder)
+{
+    NS_ENSURE_ARG_POINTER(aSortOrder);
+    *aSortOrder = m_secondarySortOrder;
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetSecondarySortOrder(nsMsgViewSortOrderValue aSortOrder)
+{
+    m_secondarySortOrder = aSortOrder;
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetSecondarySortType(nsMsgViewSortTypeValue *aSortType)
+{
+    NS_ENSURE_ARG_POINTER(aSortType);
+    *aSortType = m_secondarySort;
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetSecondarySortType(nsMsgViewSortTypeValue aSortType)
+{
+    m_secondarySort = aSortType;
+    return NS_OK;
+}
+
+nsresult nsMsgDBView::PersistFolderInfo(nsIDBFolderInfo **dbFolderInfo)
+{
+  nsresult rv = m_db->GetDBFolderInfo(dbFolderInfo);
+  NS_ENSURE_SUCCESS(rv, rv);
+  // save off sort type and order, view type and flags
+  (*dbFolderInfo)->SetSortType(m_sortType);
+  (*dbFolderInfo)->SetSortOrder(m_sortOrder);
+  (*dbFolderInfo)->SetViewFlags(m_viewFlags);
+  nsMsgViewTypeValue viewType;
+  GetViewType(&viewType);
+  (*dbFolderInfo)->SetViewType(viewType);
+  return rv;
+}
+
+
+NS_IMETHODIMP nsMsgDBView::GetViewFlags(nsMsgViewFlagsTypeValue *aViewFlags)
+{
+    NS_ENSURE_ARG_POINTER(aViewFlags);
+    *aViewFlags = m_viewFlags;
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetViewFlags(nsMsgViewFlagsTypeValue aViewFlags)
+{
+  // if we're turning off threaded display, we need to expand all so that all
+  // messages will be displayed.
+  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay && ! (aViewFlags & nsMsgViewFlagsType::kThreadedDisplay))
+  {
+    ExpandAll();
+    m_sortValid = false; // invalidate the sort so sorting will do something
+  }
+  m_viewFlags = aViewFlags;
+
+  if (m_viewFolder)
+  {
+    nsCOMPtr <nsIMsgDatabase> db;
+    nsCOMPtr <nsIDBFolderInfo> folderInfo;
+    nsresult rv = m_viewFolder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo), getter_AddRefs(db));
+    NS_ENSURE_SUCCESS(rv,rv);
+    return folderInfo->SetViewFlags(aViewFlags);
+  }
+  else
+    return NS_OK;
+}
+
+nsresult nsMsgDBView::MarkThreadOfMsgRead(nsMsgKey msgId, nsMsgViewIndex msgIndex, nsTArray<nsMsgKey> &idsMarkedRead, bool bRead)
+{
+    nsCOMPtr <nsIMsgThread> threadHdr;
+    nsresult rv = GetThreadContainingIndex(msgIndex, getter_AddRefs(threadHdr));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsMsgViewIndex threadIndex;
+
+    NS_ASSERTION(threadHdr, "threadHdr is null");
+    if (!threadHdr)
+        return NS_MSG_MESSAGE_NOT_FOUND;
+
+    nsCOMPtr<nsIMsgDBHdr> firstHdr;
+    rv = threadHdr->GetChildHdrAt(0, getter_AddRefs(firstHdr));
+    NS_ENSURE_SUCCESS(rv, rv);
+    nsMsgKey firstHdrId;
+    firstHdr->GetMessageKey(&firstHdrId);
+    if (msgId != firstHdrId)
+        threadIndex = GetIndexOfFirstDisplayedKeyInThread(threadHdr);
+    else
+        threadIndex = msgIndex;
+    return MarkThreadRead(threadHdr, threadIndex, idsMarkedRead, bRead);
+}
+
+nsresult nsMsgDBView::MarkThreadRead(nsIMsgThread *threadHdr, nsMsgViewIndex threadIndex, nsTArray<nsMsgKey> &idsMarkedRead, bool bRead)
+{
+    uint32_t numChildren;
+    threadHdr->GetNumChildren(&numChildren);
+    idsMarkedRead.SetCapacity(numChildren);
+    for (int32_t childIndex = 0; childIndex < (int32_t) numChildren ; childIndex++)
+    {
+        nsCOMPtr <nsIMsgDBHdr> msgHdr;
+        threadHdr->GetChildHdrAt(childIndex, getter_AddRefs(msgHdr));
+        NS_ASSERTION(msgHdr, "msgHdr is null");
+        if (!msgHdr)
+            continue;
+
+        bool isRead;
+
+        nsMsgKey hdrMsgId;
+        msgHdr->GetMessageKey(&hdrMsgId);
+        nsCOMPtr<nsIMsgDatabase> db;
+        nsresult rv = GetDBForHeader(msgHdr, getter_AddRefs(db));
+        NS_ENSURE_SUCCESS(rv, rv);
+        db->IsRead(hdrMsgId, &isRead);
+
+        if (isRead != bRead)
+        {
+            // MarkHdrRead will change the unread count on the thread
+            db->MarkHdrRead(msgHdr, bRead, nullptr);
+            // insert at the front.  should we insert at the end?
+            idsMarkedRead.InsertElementAt(0, hdrMsgId);
+        }
+    }
+
+    return NS_OK;
+}
+
+bool nsMsgDBView::AdjustReadFlag(nsIMsgDBHdr *msgHdr, uint32_t *msgFlags)
+{
+  // if we're a cross-folder view, just bail on this.
+  if (GetFolders())
+    return *msgFlags & nsMsgMessageFlags::Read;
+  bool isRead = false;
+  nsMsgKey msgKey;
+  msgHdr->GetMessageKey(&msgKey);
+  m_db->IsRead(msgKey, &isRead);
+    // just make sure flag is right in db.
+#ifdef DEBUG_David_Bienvenu
+  NS_ASSERTION(isRead == ((*msgFlags & nsMsgMessageFlags::Read) != 0), "msgFlags out of sync");
+#endif
+  if (isRead)
+    *msgFlags |= nsMsgMessageFlags::Read;
+  else
+    *msgFlags &= ~nsMsgMessageFlags::Read;
+  m_db->MarkHdrRead(msgHdr, isRead, nullptr);
+  return isRead;
+}
+
+// Starting from startIndex, performs the passed in navigation, including
+// any marking read needed, and returns the resultId and resultIndex of the
+// destination of the navigation.  If no message is found in the view,
+// it returns a resultId of nsMsgKey_None and an resultIndex of nsMsgViewIndex_None.
+NS_IMETHODIMP nsMsgDBView::ViewNavigate(nsMsgNavigationTypeValue motion, nsMsgKey *pResultKey, nsMsgViewIndex *pResultIndex, nsMsgViewIndex *pThreadIndex, bool wrap)
+{
+    NS_ENSURE_ARG_POINTER(pResultKey);
+    NS_ENSURE_ARG_POINTER(pResultIndex);
+    NS_ENSURE_ARG_POINTER(pThreadIndex);
+
+    int32_t currentIndex;
+    nsMsgViewIndex startIndex;
+
+    if (!mTreeSelection) // we must be in stand alone message mode
+    {
+      currentIndex = FindViewIndex(m_currentlyDisplayedMsgKey);
+    }
+    else
+    {
+      nsresult rv = mTreeSelection->GetCurrentIndex(&currentIndex);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+    startIndex = currentIndex;
+    return nsMsgDBView::NavigateFromPos(motion, startIndex, pResultKey, pResultIndex, pThreadIndex, wrap);
+}
+
+nsresult nsMsgDBView::NavigateFromPos(nsMsgNavigationTypeValue motion, nsMsgViewIndex startIndex, nsMsgKey *pResultKey, nsMsgViewIndex *pResultIndex, nsMsgViewIndex *pThreadIndex, bool wrap)
+{
+    nsresult rv = NS_OK;
+    nsMsgKey resultThreadKey;
+    nsMsgViewIndex curIndex;
+    nsMsgViewIndex lastIndex = (GetSize() > 0) ? (nsMsgViewIndex) GetSize() - 1 : nsMsgViewIndex_None;
+    nsMsgViewIndex threadIndex = nsMsgViewIndex_None;
+
+    // if there aren't any messages in the view, bail out.
+    if (GetSize() <= 0)
+    {
+      *pResultIndex = nsMsgViewIndex_None;
+      *pResultKey = nsMsgKey_None;
+      return NS_OK;
+    }
+
+    switch (motion)
+    {
+        case nsMsgNavigationType::firstMessage:
+            *pResultIndex = 0;
+            *pResultKey = m_keys[0];
+            break;
+        case nsMsgNavigationType::nextMessage:
+            // return same index and id on next on last message
+            *pResultIndex = std::min(startIndex + 1, lastIndex);
+            *pResultKey = m_keys[*pResultIndex];
+            break;
+        case nsMsgNavigationType::previousMessage:
+            *pResultIndex = (startIndex != nsMsgViewIndex_None && startIndex > 0) ? startIndex - 1 : 0;
+            *pResultKey = m_keys[*pResultIndex];
+            break;
+        case nsMsgNavigationType::lastMessage:
+            *pResultIndex = lastIndex;
+            *pResultKey = m_keys[*pResultIndex];
+            break;
+        case nsMsgNavigationType::firstFlagged:
+            rv = FindFirstFlagged(pResultIndex);
+            if (IsValidIndex(*pResultIndex))
+                *pResultKey = m_keys[*pResultIndex];
+            break;
+        case nsMsgNavigationType::nextFlagged:
+            rv = FindNextFlagged(startIndex + 1, pResultIndex);
+            if (IsValidIndex(*pResultIndex))
+                *pResultKey = m_keys[*pResultIndex];
+            break;
+        case nsMsgNavigationType::previousFlagged:
+            rv = FindPrevFlagged(startIndex, pResultIndex);
+            if (IsValidIndex(*pResultIndex))
+                *pResultKey = m_keys[*pResultIndex];
+            break;
+        case nsMsgNavigationType::firstNew:
+            rv = FindFirstNew(pResultIndex);
+            if (IsValidIndex(*pResultIndex))
+                *pResultKey = m_keys[*pResultIndex];
+            break;
+        case nsMsgNavigationType::firstUnreadMessage:
+            startIndex = nsMsgViewIndex_None;        // note fall thru - is this motion ever used?
+            MOZ_FALLTHROUGH;
+        case nsMsgNavigationType::nextUnreadMessage:
+            for (curIndex = (startIndex == nsMsgViewIndex_None) ? 0 : startIndex; curIndex <= lastIndex && lastIndex != nsMsgViewIndex_None; curIndex++) {
+                uint32_t flags = m_flags[curIndex];
+
+                // don't return start index since navigate should move
+                if (!(flags & (nsMsgMessageFlags::Read | MSG_VIEW_FLAG_DUMMY)) && (curIndex != startIndex))
+                {
+                    *pResultIndex = curIndex;
+                    *pResultKey = m_keys[*pResultIndex];
+                    break;
+                }
+                // check for collapsed thread with new children
+                if ((m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) && flags & MSG_VIEW_FLAG_ISTHREAD && flags & nsMsgMessageFlags::Elided) {
+                    nsCOMPtr <nsIMsgThread> threadHdr;
+                    GetThreadContainingIndex(curIndex, getter_AddRefs(threadHdr));
+                    NS_ENSURE_SUCCESS(rv, rv);
+
+                    NS_ASSERTION(threadHdr, "threadHdr is null");
+                    if (!threadHdr)
+                        continue;
+                    uint32_t numUnreadChildren;
+                    threadHdr->GetNumUnreadChildren(&numUnreadChildren);
+                    if (numUnreadChildren > 0)
+                    {
+                        uint32_t numExpanded;
+                        ExpandByIndex(curIndex, &numExpanded);
+                        lastIndex += numExpanded;
+                        if (pThreadIndex)
+                            *pThreadIndex = curIndex;
+                    }
+                }
+            }
+            if (curIndex > lastIndex)
+            {
+                // wrap around by starting at index 0.
+                if (wrap)
+                {
+                    nsMsgKey startKey = GetAt(startIndex);
+
+                    rv = NavigateFromPos(nsMsgNavigationType::nextUnreadMessage, nsMsgViewIndex_None, pResultKey, pResultIndex, pThreadIndex, false);
+
+                    if (*pResultKey == startKey)
+                    {
+                        // wrapped around and found start message!
+                        *pResultIndex = nsMsgViewIndex_None;
+                        *pResultKey = nsMsgKey_None;
+                    }
+                }
+                else
+                {
+                    *pResultIndex = nsMsgViewIndex_None;
+                    *pResultKey = nsMsgKey_None;
+                }
+            }
+            break;
+        case nsMsgNavigationType::previousUnreadMessage:
+            if (startIndex == nsMsgViewIndex_None)
+              break;
+            rv = FindPrevUnread(m_keys[startIndex], pResultKey,
+                                &resultThreadKey);
+            if (NS_SUCCEEDED(rv))
+            {
+                *pResultIndex = FindViewIndex(*pResultKey);
+                if (*pResultKey != resultThreadKey && (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay))
+                {
+                    threadIndex  = GetThreadIndex(*pResultIndex);
+                    if (*pResultIndex == nsMsgViewIndex_None)
+                    {
+                        nsCOMPtr <nsIMsgThread> threadHdr;
+                        nsCOMPtr <nsIMsgDBHdr> msgHdr;
+                        rv = m_db->GetMsgHdrForKey(*pResultKey, getter_AddRefs(msgHdr));
+                        NS_ENSURE_SUCCESS(rv, rv);
+                        rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(threadHdr));
+                        NS_ENSURE_SUCCESS(rv, rv);
+
+                        NS_ASSERTION(threadHdr, "threadHdr is null");
+                        if (threadHdr)
+                            break;
+                        uint32_t numUnreadChildren;
+                        threadHdr->GetNumUnreadChildren(&numUnreadChildren);
+                        if (numUnreadChildren > 0)
+                        {
+                            uint32_t numExpanded;
+                            ExpandByIndex(threadIndex, &numExpanded);
+                        }
+                        *pResultIndex = FindViewIndex(*pResultKey);
+                    }
+                }
+                if (pThreadIndex)
+                    *pThreadIndex = threadIndex;
+            }
+            break;
+        case nsMsgNavigationType::lastUnreadMessage:
+            break;
+        case nsMsgNavigationType::nextUnreadThread:
+            if (startIndex != nsMsgViewIndex_None)
+              ApplyCommandToIndices(nsMsgViewCommandType::markThreadRead, &startIndex, 1);
+
+            return NavigateFromPos(nsMsgNavigationType::nextUnreadMessage, startIndex, pResultKey, pResultIndex, pThreadIndex, true);
+        case nsMsgNavigationType::toggleThreadKilled:
+            {
+                bool resultKilled;
+                nsMsgViewIndexArray selection;
+                GetSelectedIndices(selection);
+                ToggleIgnored(selection.Elements(), selection.Length(), &threadIndex, &resultKilled);
+                if (resultKilled)
+                {
+                    return NavigateFromPos(nsMsgNavigationType::nextUnreadThread, threadIndex, pResultKey, pResultIndex, pThreadIndex, true);
+                }
+                else
+                {
+                    *pResultIndex = nsMsgViewIndex_None;
+                    *pResultKey = nsMsgKey_None;
+                    return NS_OK;
+                }
+            }
+        case nsMsgNavigationType::toggleSubthreadKilled:
+            {
+                bool resultKilled;
+                nsMsgViewIndexArray selection;
+                GetSelectedIndices(selection);
+                ToggleMessageKilled(selection.Elements(), selection.Length(),
+                    &threadIndex, &resultKilled);
+                if (resultKilled)
+                {
+                    return NavigateFromPos(nsMsgNavigationType::nextUnreadMessage, threadIndex, pResultKey, pResultIndex, pThreadIndex, true);
+                }
+                else
+                {
+                    *pResultIndex = nsMsgViewIndex_None;
+                    *pResultKey = nsMsgKey_None;
+                    return NS_OK;
+                }
+            }
+          // check where navigate says this will take us. If we have the message in the view,
+          // return it. Otherwise, return an error.
+      case nsMsgNavigationType::back:
+      case nsMsgNavigationType::forward:
+        {
+          nsCString folderUri, msgUri;
+          nsCString viewFolderUri;
+          nsCOMPtr<nsIMsgFolder> curFolder = m_viewFolder ? m_viewFolder : m_folder;
+          if (curFolder)
+            curFolder->GetURI(viewFolderUri);
+          int32_t relPos = (motion == nsMsgNavigationType::forward)
+            ? 1 : (m_currentlyDisplayedMsgKey != nsMsgKey_None) ? -1 : 0;
+          int32_t curPos;
+          nsresult rv;
+          nsCOMPtr<nsIMessenger> messenger (do_QueryReferent(mMessengerWeak, &rv));
+          NS_ENSURE_SUCCESS(rv, rv);
+          rv = messenger->GetFolderUriAtNavigatePos(relPos, folderUri);
+          NS_ENSURE_SUCCESS(rv, rv);
+          // Empty viewFolderUri means we're in a search results view.
+          if (viewFolderUri.IsEmpty() || folderUri.Equals(viewFolderUri))
+          {
+            nsCOMPtr <nsIMsgDBHdr> msgHdr;
+            rv = messenger->GetMsgUriAtNavigatePos(relPos, msgUri);
+            NS_ENSURE_SUCCESS(rv, rv);
+            messenger->MsgHdrFromURI(msgUri, getter_AddRefs(msgHdr));
+            if (msgHdr)
+            {
+              messenger->GetNavigatePos(&curPos);
+              curPos += relPos;
+              *pResultIndex = FindHdr(msgHdr);
+              messenger->SetNavigatePos(curPos);
+              msgHdr->GetMessageKey(pResultKey);
+              return NS_OK;
+            }
+          }
+          *pResultIndex = nsMsgViewIndex_None;
+          *pResultKey = nsMsgKey_None;
+          break;
+
+        }
+        default:
+            NS_ERROR("unsupported motion");
+            break;
+    }
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::NavigateStatus(nsMsgNavigationTypeValue motion, bool *_retval)
+{
+    NS_ENSURE_ARG_POINTER(_retval);
+
+    bool enable = false;
+    nsresult rv = NS_ERROR_FAILURE;
+    nsMsgKey resultKey = nsMsgKey_None;
+    int32_t index = nsMsgKey_None;
+    nsMsgViewIndex resultIndex = nsMsgViewIndex_None;
+    if (mTreeSelection)
+      (void) mTreeSelection->GetCurrentIndex(&index);
+    else
+      index = FindViewIndex(m_currentlyDisplayedMsgKey);
+    nsCOMPtr<nsIMessenger> messenger (do_QueryReferent(mMessengerWeak));
+    // warning - we no longer validate index up front because fe passes in -1 for no
+    // selection, so if you use index, be sure to validate it before using it
+    // as an array index.
+    switch (motion)
+    {
+        case nsMsgNavigationType::firstMessage:
+        case nsMsgNavigationType::lastMessage:
+            if (GetSize() > 0)
+                enable = true;
+            break;
+        case nsMsgNavigationType::nextMessage:
+            if (IsValidIndex(index) && uint32_t(index) < GetSize() - 1)
+                enable = true;
+            break;
+        case nsMsgNavigationType::previousMessage:
+            if (IsValidIndex(index) && index != 0 && GetSize() > 1)
+                enable = true;
+            break;
+        case nsMsgNavigationType::firstFlagged:
+            rv = FindFirstFlagged(&resultIndex);
+            enable = (NS_SUCCEEDED(rv) && resultIndex != nsMsgViewIndex_None);
+            break;
+        case nsMsgNavigationType::nextFlagged:
+            rv = FindNextFlagged(index + 1, &resultIndex);
+            enable = (NS_SUCCEEDED(rv) && resultIndex != nsMsgViewIndex_None);
+            break;
+        case nsMsgNavigationType::previousFlagged:
+            if (IsValidIndex(index) && index != 0)
+                rv = FindPrevFlagged(index, &resultIndex);
+            enable = (NS_SUCCEEDED(rv) && resultIndex != nsMsgViewIndex_None);
+            break;
+        case nsMsgNavigationType::firstNew:
+            rv = FindFirstNew(&resultIndex);
+            enable = (NS_SUCCEEDED(rv) && resultIndex != nsMsgViewIndex_None);
+            break;
+        case nsMsgNavigationType::readMore:
+            enable = true;  // for now, always true.
+            break;
+        case nsMsgNavigationType::nextFolder:
+        case nsMsgNavigationType::nextUnreadThread:
+        case nsMsgNavigationType::nextUnreadMessage:
+        case nsMsgNavigationType::toggleThreadKilled:
+            enable = true;  // always enabled
+            break;
+        case nsMsgNavigationType::previousUnreadMessage:
+            if (IsValidIndex(index))
+            {
+                nsMsgKey threadId;
+                rv = FindPrevUnread(m_keys[index], &resultKey, &threadId);
+                enable = (resultKey != nsMsgKey_None);
+            }
+            break;
+        case nsMsgNavigationType::forward:
+        case nsMsgNavigationType::back:
+        {
+          uint32_t curPos;
+          uint32_t historyCount;
+
+          if (messenger)
+          {
+            messenger->GetNavigateHistory(&curPos, &historyCount, nullptr);
+            int32_t desiredPos = (int32_t) curPos;
+            if (motion == nsMsgNavigationType::forward)
+              desiredPos++;
+            else
+              desiredPos--; //? operator code didn't work for me
+            enable = (desiredPos >= 0 && desiredPos < (int32_t) historyCount / 2);
+          }
+        }
+          break;
+
+        default:
+            NS_ERROR("unexpected");
+            break;
+    }
+
+    *_retval = enable;
+    return NS_OK;
+}
+
+// Note that these routines do NOT expand collapsed threads! This mimics the old behaviour,
+// but it's also because we don't remember whether a thread contains a flagged message the
+// same way we remember if a thread contains new messages. It would be painful to dive down
+// into each collapsed thread to update navigate status.
+// We could cache this info, but it would still be expensive the first time this status needs
+// to get updated.
+nsresult nsMsgDBView::FindNextFlagged(nsMsgViewIndex startIndex, nsMsgViewIndex *pResultIndex)
+{
+    nsMsgViewIndex lastIndex = (nsMsgViewIndex) GetSize() - 1;
+    nsMsgViewIndex curIndex;
+
+    *pResultIndex = nsMsgViewIndex_None;
+
+    if (GetSize() > 0)
+    {
+        for (curIndex = startIndex; curIndex <= lastIndex; curIndex++)
+        {
+            uint32_t flags = m_flags[curIndex];
+            if (flags & nsMsgMessageFlags::Marked)
+            {
+                *pResultIndex = curIndex;
+                break;
+            }
+        }
+    }
+
+    return NS_OK;
+}
+
+nsresult nsMsgDBView::FindFirstNew(nsMsgViewIndex *pResultIndex)
+{
+  if (m_db)
+  {
+    nsMsgKey firstNewKey = nsMsgKey_None;
+    m_db->GetFirstNew(&firstNewKey);
+    *pResultIndex = (firstNewKey != nsMsgKey_None)
+        ? FindKey(firstNewKey, true) : nsMsgViewIndex_None;
+  }
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::FindPrevUnread(nsMsgKey startKey, nsMsgKey *pResultKey,
+                                     nsMsgKey *resultThreadId)
+{
+    nsMsgViewIndex startIndex = FindViewIndex(startKey);
+    nsMsgViewIndex curIndex = startIndex;
+    nsresult rv = NS_MSG_MESSAGE_NOT_FOUND;
+
+    if (startIndex == nsMsgViewIndex_None)
+        return NS_MSG_MESSAGE_NOT_FOUND;
+
+    *pResultKey = nsMsgKey_None;
+    if (resultThreadId)
+        *resultThreadId = nsMsgKey_None;
+
+    for (; (int) curIndex >= 0 && (*pResultKey == nsMsgKey_None); curIndex--)
+    {
+        uint32_t flags = m_flags[curIndex];
+
+        if (curIndex != startIndex && flags & MSG_VIEW_FLAG_ISTHREAD && flags & nsMsgMessageFlags::Elided)
+        {
+            NS_ERROR("fix this");
+            //nsMsgKey threadId = m_keys[curIndex];
+            //rv = m_db->GetUnreadKeyInThread(threadId, pResultKey, resultThreadId);
+            if (NS_SUCCEEDED(rv) && (*pResultKey != nsMsgKey_None))
+                break;
+        }
+        if (!(flags & (nsMsgMessageFlags::Read | MSG_VIEW_FLAG_DUMMY)) && (curIndex != startIndex))
+        {
+            *pResultKey = m_keys[curIndex];
+            rv = NS_OK;
+            break;
+        }
+    }
+    // found unread message but we don't know the thread
+    NS_ASSERTION(!(*pResultKey != nsMsgKey_None && resultThreadId && *resultThreadId == nsMsgKey_None),
+      "fix this");
+    return rv;
+}
+
+nsresult nsMsgDBView::FindFirstFlagged(nsMsgViewIndex *pResultIndex)
+{
+    return FindNextFlagged(0, pResultIndex);
+}
+
+nsresult nsMsgDBView::FindPrevFlagged(nsMsgViewIndex startIndex, nsMsgViewIndex *pResultIndex)
+{
+    nsMsgViewIndex curIndex;
+
+    *pResultIndex = nsMsgViewIndex_None;
+
+    if (GetSize() > 0 && IsValidIndex(startIndex))
+    {
+        curIndex = startIndex;
+        do
+        {
+            if (curIndex != 0)
+                curIndex--;
+
+            uint32_t flags = m_flags[curIndex];
+            if (flags & nsMsgMessageFlags::Marked)
+            {
+                *pResultIndex = curIndex;
+                break;
+            }
+        }
+        while (curIndex != 0);
+    }
+    return NS_OK;
+}
+
+bool nsMsgDBView::IsValidIndex(nsMsgViewIndex index)
+{
+    return index != nsMsgViewIndex_None &&
+           (index < (nsMsgViewIndex) m_keys.Length());
+}
+
+nsresult nsMsgDBView::OrExtraFlag(nsMsgViewIndex index, uint32_t orflag)
+{
+  uint32_t  flag;
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  flag = m_flags[index];
+  flag |= orflag;
+  m_flags[index] = flag;
+  OnExtraFlagChanged(index, flag);
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::AndExtraFlag(nsMsgViewIndex index, uint32_t andflag)
+{
+  uint32_t  flag;
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  flag = m_flags[index];
+  flag &= andflag;
+  m_flags[index] = flag;
+  OnExtraFlagChanged(index, flag);
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::SetExtraFlag(nsMsgViewIndex index, uint32_t extraflag)
+{
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+  m_flags[index] = extraflag;
+  OnExtraFlagChanged(index, extraflag);
+  return NS_OK;
+}
+
+
+nsresult nsMsgDBView::ToggleIgnored(nsMsgViewIndex * indices, int32_t numIndices, nsMsgViewIndex *resultIndex, bool *resultToggleState)
+{
+  nsCOMPtr <nsIMsgThread> thread;
+
+  // Ignored state is toggled based on the first selected thread
+  nsMsgViewIndex threadIndex = GetThreadFromMsgIndex(indices[0], getter_AddRefs(thread));
+  uint32_t threadFlags;
+  thread->GetFlags(&threadFlags);
+  uint32_t ignored = threadFlags & nsMsgMessageFlags::Ignored;
+
+  // Process threads in reverse order
+  // Otherwise collapsing the threads will invalidate the indices
+  threadIndex = nsMsgViewIndex_None;
+  while (numIndices)
+  {
+    numIndices--;
+    if (indices[numIndices] < threadIndex)
+    {
+      threadIndex = GetThreadFromMsgIndex(indices[numIndices], getter_AddRefs(thread));
+      thread->GetFlags(&threadFlags);
+      if ((threadFlags & nsMsgMessageFlags::Ignored) == ignored)
+        SetThreadIgnored(thread, threadIndex, !ignored);
+    }
+  }
+
+  if (resultIndex)
+    *resultIndex = threadIndex;
+  if (resultToggleState)
+    *resultToggleState = !ignored;
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::ToggleMessageKilled(nsMsgViewIndex * indices, int32_t numIndices, nsMsgViewIndex *resultIndex, bool *resultToggleState)
+{
+  NS_ENSURE_ARG_POINTER(resultToggleState);
+
+  nsCOMPtr <nsIMsgDBHdr> header;
+  // Ignored state is toggled based on the first selected message
+  nsresult rv = GetMsgHdrForViewIndex(indices[0], getter_AddRefs(header));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint32_t msgFlags;
+  header->GetFlags(&msgFlags);
+  uint32_t ignored = msgFlags & nsMsgMessageFlags::Ignored;
+
+  // Process messages in reverse order
+  // Otherwise the indices may be invalidated...
+  nsMsgViewIndex msgIndex = nsMsgViewIndex_None;
+  while (numIndices)
+  {
+    numIndices--;
+    if (indices[numIndices] < msgIndex)
+    {
+      msgIndex = indices[numIndices];
+      rv = GetMsgHdrForViewIndex(msgIndex, getter_AddRefs(header));
+      NS_ENSURE_SUCCESS(rv, rv);
+      header->GetFlags(&msgFlags);
+      if ((msgFlags & nsMsgMessageFlags::Ignored) == ignored)
+        SetSubthreadKilled(header, msgIndex, !ignored);
+    }
+  }
+
+  if (resultIndex)
+    *resultIndex = msgIndex;
+  if (resultToggleState)
+    *resultToggleState = !ignored;
+
+  return NS_OK;
+}
+
+nsMsgViewIndex  nsMsgDBView::GetThreadFromMsgIndex(nsMsgViewIndex index,
+                                                   nsIMsgThread **threadHdr)
+{
+  nsMsgKey        msgKey = GetAt(index);
+  nsMsgViewIndex  threadIndex;
+
+  if (threadHdr == nullptr)
+    return nsMsgViewIndex_None;
+
+  nsresult rv = GetThreadContainingIndex(index, threadHdr);
+  NS_ENSURE_SUCCESS(rv,nsMsgViewIndex_None);
+
+  if (*threadHdr == nullptr)
+    return nsMsgViewIndex_None;
+
+  nsMsgKey threadKey;
+  (*threadHdr)->GetThreadKey(&threadKey);
+  if (msgKey !=threadKey)
+    threadIndex = GetIndexOfFirstDisplayedKeyInThread(*threadHdr);
+  else
+    threadIndex = index;
+  return threadIndex;
+}
+
+nsresult nsMsgDBView::ToggleWatched( nsMsgViewIndex* indices,  int32_t numIndices)
+{
+  nsCOMPtr <nsIMsgThread> thread;
+
+  // Watched state is toggled based on the first selected thread
+  nsMsgViewIndex threadIndex = GetThreadFromMsgIndex(indices[0], getter_AddRefs(thread));
+  uint32_t threadFlags;
+  thread->GetFlags(&threadFlags);
+  uint32_t watched = threadFlags & nsMsgMessageFlags::Watched;
+
+  // Process threads in reverse order
+  // for consistency with ToggleIgnored
+  threadIndex = nsMsgViewIndex_None;
+  while (numIndices)
+  {
+    numIndices--;
+    if (indices[numIndices] < threadIndex)
+    {
+      threadIndex = GetThreadFromMsgIndex(indices[numIndices], getter_AddRefs(thread));
+      thread->GetFlags(&threadFlags);
+      if ((threadFlags & nsMsgMessageFlags::Watched) == watched)
+        SetThreadWatched(thread, threadIndex, !watched);
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::SetThreadIgnored(nsIMsgThread *thread, nsMsgViewIndex threadIndex, bool ignored)
+{
+  if (!IsValidIndex(threadIndex))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  NoteChange(threadIndex, 1, nsMsgViewNotificationCode::changed);
+  if (ignored)
+  {
+    nsTArray<nsMsgKey> idsMarkedRead;
+
+    MarkThreadRead(thread, threadIndex, idsMarkedRead, true);
+    CollapseByIndex(threadIndex, nullptr);
+  }
+
+  if (!m_db)
+    return NS_ERROR_FAILURE;
+  return m_db->MarkThreadIgnored(thread, m_keys[threadIndex], ignored, this);
+}
+
+nsresult nsMsgDBView::SetSubthreadKilled(nsIMsgDBHdr *header, nsMsgViewIndex msgIndex, bool ignored)
+{
+  if (!IsValidIndex(msgIndex))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  NoteChange(msgIndex, 1, nsMsgViewNotificationCode::changed);
+
+  if (!m_db)
+    return NS_ERROR_FAILURE;
+  nsresult rv = m_db->MarkHeaderKilled(header, ignored, this);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (ignored)
+  {
+    nsCOMPtr <nsIMsgThread> thread;
+    nsresult rv;
+    rv = GetThreadContainingMsgHdr(header, getter_AddRefs(thread));
+    if (NS_FAILED(rv))
+      return NS_OK; // So we didn't mark threads read
+
+    uint32_t children, current;
+    thread->GetNumChildren(&children);
+
+    nsMsgKey headKey;
+    header->GetMessageKey(&headKey);
+
+    for (current = 0; current < children; current++)
+    {
+       nsMsgKey newKey;
+       thread->GetChildKeyAt(current, &newKey);
+       if (newKey == headKey)
+         break;
+    }
+
+    // Process all messages, starting with this message.
+    for (; current < children; current++)
+    {
+       nsCOMPtr <nsIMsgDBHdr> nextHdr;
+       bool isKilled;
+
+       thread->GetChildHdrAt(current, getter_AddRefs(nextHdr));
+       nextHdr->GetIsKilled(&isKilled);
+
+       // Ideally, the messages should stop processing here.
+       // However, the children are ordered not by thread...
+       if (isKilled)
+         nextHdr->MarkRead(true);
+    }
+  }
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::SetThreadWatched(nsIMsgThread *thread, nsMsgViewIndex index, bool watched)
+{
+  if (!IsValidIndex(index))
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  NoteChange(index, 1, nsMsgViewNotificationCode::changed);
+  return m_db->MarkThreadWatched(thread, m_keys[index], watched, this);
+}
+
+NS_IMETHODIMP nsMsgDBView::GetMsgFolder(nsIMsgFolder **aMsgFolder)
+{
+  NS_ENSURE_ARG_POINTER(aMsgFolder);
+  NS_IF_ADDREF(*aMsgFolder = m_folder);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SetViewFolder(nsIMsgFolder *aMsgFolder)
+{
+  m_viewFolder = aMsgFolder;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetViewFolder(nsIMsgFolder **aMsgFolder)
+{
+  NS_ENSURE_ARG_POINTER(aMsgFolder);
+  NS_IF_ADDREF(*aMsgFolder = m_viewFolder);
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsMsgDBView::GetNumSelected(uint32_t *aNumSelected)
+{
+  NS_ENSURE_ARG_POINTER(aNumSelected);
+
+  if (!mTreeSelection)
+  {
+    // No tree selection can mean we're in the stand alone mode.
+    *aNumSelected = (m_currentlyDisplayedMsgKey != nsMsgKey_None) ? 1 : 0;
+    return NS_OK;
+  }
+
+  bool includeCollapsedMsgs = OperateOnMsgsInCollapsedThreads();
+
+  // We call this a lot from the front end JS, so make it fast.
+  nsresult rv = mTreeSelection->GetCount((int32_t*)aNumSelected);
+  if (!*aNumSelected || !includeCollapsedMsgs ||
+       !(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay))
+    return rv;
+
+  int32_t numSelectedIncludingCollapsed = *aNumSelected;
+  nsMsgViewIndexArray selection;
+  GetSelectedIndices(selection);
+  int32_t numIndices = selection.Length();
+  // iterate over the selection, counting up the messages in collapsed
+  // threads.
+  for (int32_t i = 0; i < numIndices; i++)
+  {
+    if (m_flags[selection[i]] & nsMsgMessageFlags::Elided)
+    {
+      int32_t collapsedCount;
+      ExpansionDelta(selection[i], &collapsedCount);
+      numSelectedIncludingCollapsed += collapsedCount;
+    }
+  }
+  *aNumSelected = numSelectedIncludingCollapsed;
+  return rv;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetNumMsgsInView(int32_t *aNumMsgs)
+{
+  NS_ENSURE_ARG_POINTER(aNumMsgs);
+  return (m_folder) ? m_folder->GetTotalMessages(false, aNumMsgs) :
+                    NS_ERROR_FAILURE;
+}
+/**
+ * @note For the IMAP delete model, this applies to both deleting and
+ *       undeleting a message.
+ */
+NS_IMETHODIMP
+nsMsgDBView::GetMsgToSelectAfterDelete(nsMsgViewIndex *msgToSelectAfterDelete)
+{
+  NS_ENSURE_ARG_POINTER(msgToSelectAfterDelete);
+  *msgToSelectAfterDelete = nsMsgViewIndex_None;
+
+  bool isMultiSelect = false;
+  int32_t startFirstRange = nsMsgViewIndex_None;
+  int32_t endFirstRange = nsMsgViewIndex_None;
+  if (!mTreeSelection)
+  {
+    // If we don't have a tree selection then we must be in stand alone mode.
+    // return the index of the current message key as the first selected index.
+    *msgToSelectAfterDelete = FindViewIndex(m_currentlyDisplayedMsgKey);
+  }
+  else
+  {
+    int32_t selectionCount;
+    int32_t startRange;
+    int32_t endRange;
+    nsresult rv = mTreeSelection->GetRangeCount(&selectionCount);
+    NS_ENSURE_SUCCESS(rv, rv);
+    for (int32_t i = 0; i < selectionCount; i++)
+    {
+      rv = mTreeSelection->GetRangeAt(i, &startRange, &endRange);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // save off the first range in case we need it later
+      if (i == 0) {
+        startFirstRange = startRange;
+        endFirstRange = endRange;
+      } else {
+        // If the tree selection is goofy (eg adjacent or overlapping ranges),
+        // complain about it, but don't try and cope.  Just live with the fact
+        // that one of the deleted messages is going to end up selected.
+        NS_WARNING_ASSERTION(endFirstRange != startRange,
+                             "goofy tree selection state: two ranges are adjacent!");
+      }
+      *msgToSelectAfterDelete = std::min(*msgToSelectAfterDelete,
+                                       (nsMsgViewIndex)startRange);
+    }
+
+    // Multiple selection either using Ctrl, Shift, or one of the affordances
+    // to select an entire thread.
+    isMultiSelect = (selectionCount > 1 || (endRange-startRange) > 0);
+  }
+
+  if (*msgToSelectAfterDelete == nsMsgViewIndex_None)
+    return NS_OK;
+
+  nsCOMPtr<nsIMsgFolder> folder;
+  GetMsgFolder(getter_AddRefs(folder));
+  nsCOMPtr<nsIMsgImapMailFolder> imapFolder = do_QueryInterface(folder);
+  bool thisIsImapFolder = (imapFolder != nullptr);
+  // Need to update the imap-delete model, can change more than once in a session.
+  if (thisIsImapFolder)
+    GetImapDeleteModel(nullptr);
+
+  // If mail.delete_matches_sort_order is true,
+  // for views sorted in descending order (newest at the top), make msgToSelectAfterDelete
+  // advance in the same direction as the sort order.
+  bool deleteMatchesSort = false;
+  if (m_sortOrder == nsMsgViewSortOrder::descending && *msgToSelectAfterDelete)
+  {
+    nsresult rv;
+    nsCOMPtr<nsIPrefBranch> prefBranch (do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
+    NS_ENSURE_SUCCESS(rv, rv);
+    prefBranch->GetBoolPref("mail.delete_matches_sort_order", &deleteMatchesSort);
+  }
+
+  if (mDeleteModel == nsMsgImapDeleteModels::IMAPDelete)
+  {
+    if (isMultiSelect)
+    {
+      if (deleteMatchesSort)
+        *msgToSelectAfterDelete = startFirstRange - 1;
+      else
+        *msgToSelectAfterDelete = endFirstRange + 1;
+    }
+    else
+    {
+      if (deleteMatchesSort)
+        *msgToSelectAfterDelete -= 1;
+      else
+        *msgToSelectAfterDelete += 1;
+    }
+  }
+  else if (deleteMatchesSort)
+  {
+    *msgToSelectAfterDelete -= 1;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::GetRemoveRowOnMoveOrDelete(bool *aRemoveRowOnMoveOrDelete)
+{
+  NS_ENSURE_ARG_POINTER(aRemoveRowOnMoveOrDelete);
+  nsCOMPtr <nsIMsgImapMailFolder> imapFolder = do_QueryInterface(m_folder);
+  if (!imapFolder)
+  {
+    *aRemoveRowOnMoveOrDelete = true;
+    return NS_OK;
+  }
+
+  // need to update the imap-delete model, can change more than once in a session.
+  GetImapDeleteModel(nullptr);
+
+  // unlike the other imap delete models, "mark as deleted" does not remove rows on delete (or move)
+  *aRemoveRowOnMoveOrDelete = (mDeleteModel != nsMsgImapDeleteModels::IMAPDelete);
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsMsgDBView::GetCurrentlyDisplayedMessage(nsMsgViewIndex *currentlyDisplayedMessage)
+{
+  NS_ENSURE_ARG_POINTER(currentlyDisplayedMessage);
+  *currentlyDisplayedMessage = FindViewIndex(m_currentlyDisplayedMsgKey);
+  return NS_OK;
+}
+
+// if nothing selected, return an NS_ERROR
+NS_IMETHODIMP
+nsMsgDBView::GetHdrForFirstSelectedMessage(nsIMsgDBHdr **hdr)
+{
+  NS_ENSURE_ARG_POINTER(hdr);
+
+  nsresult rv;
+  nsMsgKey key;
+  rv = GetKeyForFirstSelectedMessage(&key);
+  // don't assert, it is legal for nothing to be selected
+  if (NS_FAILED(rv)) return rv;
+
+  if (!m_db)
+    return NS_MSG_MESSAGE_NOT_FOUND;
+
+  rv = m_db->GetMsgHdrForKey(key, hdr);
+  NS_ENSURE_SUCCESS(rv,rv);
+  return NS_OK;
+}
+
+// if nothing selected, return an NS_ERROR
+NS_IMETHODIMP
+nsMsgDBView::GetURIForFirstSelectedMessage(nsACString &uri)
+{
+  nsresult rv;
+  nsMsgViewIndex viewIndex;
+  rv = GetViewIndexForFirstSelectedMsg(&viewIndex);
+  // don't assert, it is legal for nothing to be selected
+  if (NS_FAILED(rv)) return rv;
+
+  return GetURIForViewIndex(viewIndex, uri);
+}
+
+NS_IMETHODIMP
+nsMsgDBView::OnDeleteCompleted(bool aSucceeded)
+{
+  if (m_deletingRows && aSucceeded)
+  {
+    uint32_t numIndices = mIndicesToNoteChange.Length();
+    if (numIndices && mTree)
+    {
+      if (numIndices > 1)
+        mIndicesToNoteChange.Sort();
+
+      // the call to NoteChange() has to happen after we are done removing the keys
+      // as NoteChange() will call RowCountChanged() which will call our GetRowCount()
+      if (numIndices > 1)
+        mTree->BeginUpdateBatch();
+      for (uint32_t i = 0; i < numIndices; i++)
+        NoteChange(mIndicesToNoteChange[i], -1, nsMsgViewNotificationCode::insertOrDelete);
+      if (numIndices > 1)
+        mTree->EndUpdateBatch();
+    }
+    mIndicesToNoteChange.Clear();
+  }
+
+ m_deletingRows = false;
+ return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetDb(nsIMsgDatabase **aDB)
+{
+  NS_ENSURE_ARG_POINTER(aDB);
+  NS_IF_ADDREF(*aDB = m_db);
+  return NS_OK;
+}
+
+bool nsMsgDBView::OfflineMsgSelected(nsMsgViewIndex * indices, int32_t numIndices)
+{
+  nsCOMPtr <nsIMsgLocalMailFolder> localFolder = do_QueryInterface(m_folder);
+  if (localFolder)
+    return true;
+
+  for (nsMsgViewIndex index = 0; index < (nsMsgViewIndex) numIndices; index++)
+  {
+    // For cross-folder saved searches, we need to check if any message
+    // is in a local folder.
+    if (!m_folder)
+    {
+      nsCOMPtr<nsIMsgFolder> folder;
+      GetFolderForViewIndex(indices[index], getter_AddRefs(folder));
+      nsCOMPtr <nsIMsgLocalMailFolder> localFolder = do_QueryInterface(folder);
+      if (localFolder)
+        return true;
+    }
+
+    uint32_t flags = m_flags[indices[index]];
+    if ((flags & nsMsgMessageFlags::Offline))
+      return true;
+  }
+  return false;
+}
+
+bool nsMsgDBView::NonDummyMsgSelected(nsMsgViewIndex * indices, int32_t numIndices)
+{
+  bool includeCollapsedMsgs = OperateOnMsgsInCollapsedThreads();
+
+  for (nsMsgViewIndex index = 0; index < (nsMsgViewIndex) numIndices; index++)
+  {
+    uint32_t flags = m_flags[indices[index]];
+    // We now treat having a collapsed dummy message selected as if
+    // the whole group was selected so we can apply commands to the group.
+    if (!(flags & MSG_VIEW_FLAG_DUMMY) ||
+        (flags & nsMsgMessageFlags::Elided && includeCollapsedMsgs))
+      return true;
+  }
+  return false;
+}
+
+NS_IMETHODIMP nsMsgDBView::GetViewIndexForFirstSelectedMsg(nsMsgViewIndex *aViewIndex)
+{
+  NS_ENSURE_ARG_POINTER(aViewIndex);
+  // If we don't have a tree selection we must be in stand alone mode...
+  if (!mTreeSelection)
+  {
+    *aViewIndex = m_currentlyDisplayedViewIndex;
+    return NS_OK;
+  }
+
+  int32_t startRange;
+  int32_t endRange;
+  nsresult rv = mTreeSelection->GetRangeAt(0, &startRange, &endRange);
+  // don't assert, it is legal for nothing to be selected
+  if (NS_FAILED(rv))
+    return rv;
+
+  // check that the first index is valid, it may not be if nothing is selected
+  if (startRange < 0 || uint32_t(startRange) >= GetSize())
+    return NS_ERROR_UNEXPECTED;
+
+  *aViewIndex = startRange;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::GetKeyForFirstSelectedMessage(nsMsgKey *key)
+{
+  NS_ENSURE_ARG_POINTER(key);
+  // If we don't have a tree selection we must be in stand alone mode...
+  if (!mTreeSelection)
+  {
+    *key = m_currentlyDisplayedMsgKey;
+    return NS_OK;
+  }
+
+  int32_t startRange;
+  int32_t endRange;
+  nsresult rv = mTreeSelection->GetRangeAt(0, &startRange, &endRange);
+  // don't assert, it is legal for nothing to be selected
+  if (NS_FAILED(rv))
+    return rv;
+
+  // check that the first index is valid, it may not be if nothing is selected
+  if (startRange < 0 || uint32_t(startRange) >= GetSize())
+    return NS_ERROR_UNEXPECTED;
+
+  if (m_flags[startRange] & MSG_VIEW_FLAG_DUMMY)
+    return NS_MSG_INVALID_DBVIEW_INDEX;
+
+  *key = m_keys[startRange];
+  return NS_OK;
+}
+
+nsCOMArray<nsIMsgFolder>* nsMsgDBView::GetFolders()
+{
+  return nullptr;
+}
+
+nsresult nsMsgDBView::AdjustRowCount(int32_t rowCountBeforeSort, int32_t rowCountAfterSort)
+{
+  int32_t rowChange = rowCountAfterSort - rowCountBeforeSort;
+
+  if (rowChange)
+  {
+    // this is not safe to use when you have a selection
+    // RowCountChanged() will call AdjustSelection()
+    uint32_t numSelected = 0;
+    GetNumSelected(&numSelected);
+    NS_ASSERTION(numSelected == 0, "it is not save to call AdjustRowCount() when you have a selection");
+
+    if (mTree)
+      mTree->RowCountChanged(0, rowChange);
+  }
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::GetImapDeleteModel(nsIMsgFolder *folder)
+{
+   nsresult rv = NS_OK;
+   nsCOMPtr <nsIMsgIncomingServer> server;
+   if (folder) //for the search view
+     folder->GetServer(getter_AddRefs(server));
+   else if (m_folder)
+     m_folder->GetServer(getter_AddRefs(server));
+   nsCOMPtr<nsIImapIncomingServer> imapServer = do_QueryInterface(server, &rv);
+   if (NS_SUCCEEDED(rv) && imapServer )
+     imapServer->GetDeleteModel(&mDeleteModel);
+   return rv;
+}
+
+
+//
+// CanDrop
+//
+// Can't drop on the thread pane.
+//
+NS_IMETHODIMP nsMsgDBView::CanDrop(int32_t index,
+                                   int32_t orient,
+                                   nsIDOMDataTransfer *dataTransfer,
+                                   bool *_retval)
+{
+  NS_ENSURE_ARG_POINTER(_retval);
+  *_retval = false;
+
+  return NS_OK;
+}
+
+
+//
+// Drop
+//
+// Can't drop on the thread pane.
+//
+NS_IMETHODIMP nsMsgDBView::Drop(int32_t row,
+                                int32_t orient,
+                                nsIDOMDataTransfer *dataTransfer)
+{
+  return NS_OK;
+}
+
+
+//
+// IsSorted
+//
+// ...
+//
+NS_IMETHODIMP nsMsgDBView::IsSorted(bool *_retval)
+{
+  *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SelectFolderMsgByKey(nsIMsgFolder *aFolder, nsMsgKey aKey)
+{
+  NS_ENSURE_ARG_POINTER(aFolder);
+  if (aKey == nsMsgKey_None)
+    return NS_ERROR_FAILURE;
+
+  // this is OK for non search views.
+
+  nsMsgViewIndex viewIndex = FindKey(aKey, true /* expand */);
+
+  if (mTree)
+    mTreeSelection->SetCurrentIndex(viewIndex);
+
+  // make sure the current message is once again visible in the thread pane
+  // so we don't have to go search for it in the thread pane
+  if (mTree && viewIndex != nsMsgViewIndex_None)
+  {
+    mTreeSelection->Select(viewIndex);
+    mTree->EnsureRowIsVisible(viewIndex);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsMsgDBView::SelectMsgByKey(nsMsgKey aKey)
+{
+  NS_ASSERTION(aKey != nsMsgKey_None, "bad key");
+  if (aKey == nsMsgKey_None)
+    return NS_OK;
+
+  // use SaveAndClearSelection()
+  // and RestoreSelection() so that we'll clear the current selection
+  // but pass in a different key array so that we'll
+  // select (and load) the desired message
+
+  AutoTArray<nsMsgKey, 1> preservedSelection;
+  nsresult rv = SaveAndClearSelection(nullptr, preservedSelection);
+  NS_ENSURE_SUCCESS(rv,rv);
+
+  // now, restore our desired selection
+  AutoTArray<nsMsgKey, 1> keyArray;
+  keyArray.AppendElement(aKey);
+
+  // if the key was not found
+  // (this can happen with "remember last selected message")
+  // nothing will be selected
+  rv = RestoreSelection(aKey, keyArray);
+  NS_ENSURE_SUCCESS(rv,rv);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::CloneDBView(nsIMessenger *aMessengerInstance, nsIMsgWindow *aMsgWindow, nsIMsgDBViewCommandUpdater *aCmdUpdater, nsIMsgDBView **_retval)
+{
+  nsMsgDBView* newMsgDBView = new nsMsgDBView();
+
+  if (!newMsgDBView)
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  nsresult rv = CopyDBView(newMsgDBView, aMessengerInstance, aMsgWindow, aCmdUpdater);
+  NS_ENSURE_SUCCESS(rv,rv);
+
+  NS_IF_ADDREF(*_retval = newMsgDBView);
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::CopyDBView(nsMsgDBView *aNewMsgDBView, nsIMessenger *aMessengerInstance, nsIMsgWindow *aMsgWindow, nsIMsgDBViewCommandUpdater *aCmdUpdater)
+{
+  NS_ENSURE_ARG_POINTER(aNewMsgDBView);
+  if (aMsgWindow)
+  {
+    aNewMsgDBView->mMsgWindowWeak = do_GetWeakReference(aMsgWindow);
+    aMsgWindow->SetOpenFolder(m_viewFolder? m_viewFolder : m_folder);
+  }
+  aNewMsgDBView->mMessengerWeak = do_GetWeakReference(aMessengerInstance);
+  aNewMsgDBView->mCommandUpdater = aCmdUpdater;
+  aNewMsgDBView->m_folder = m_folder;
+  aNewMsgDBView->m_viewFlags = m_viewFlags;
+  aNewMsgDBView->m_sortOrder = m_sortOrder;
+  aNewMsgDBView->m_sortType = m_sortType;
+  aNewMsgDBView->m_curCustomColumn = m_curCustomColumn;
+  aNewMsgDBView->m_secondarySort = m_secondarySort;
+  aNewMsgDBView->m_secondarySortOrder = m_secondarySortOrder;
+  aNewMsgDBView->m_secondaryCustomColumn = m_secondaryCustomColumn;
+  aNewMsgDBView->m_db = m_db;
+  aNewMsgDBView->mDateFormatter = mDateFormatter;
+  if (m_db)
+    aNewMsgDBView->m_db->AddListener(aNewMsgDBView);
+  aNewMsgDBView->mIsNews = mIsNews;
+  aNewMsgDBView->mIsRss = mIsRss;
+  aNewMsgDBView->mIsXFVirtual = mIsXFVirtual;
+  aNewMsgDBView->mShowSizeInLines = mShowSizeInLines;
+  aNewMsgDBView->mDeleteModel = mDeleteModel;
+  aNewMsgDBView->m_flags = m_flags;
+  aNewMsgDBView->m_levels = m_levels;
+  aNewMsgDBView->m_keys = m_keys;
+
+  aNewMsgDBView->m_customColumnHandlerIDs = m_customColumnHandlerIDs;
+  aNewMsgDBView->m_customColumnHandlers.AppendObjects(m_customColumnHandlers);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::GetSearchSession(nsIMsgSearchSession* *aSession)
+{
+  NS_ASSERTION(false, "should be overriden by child class");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::SetSearchSession(nsIMsgSearchSession *aSession)
+{
+  NS_ASSERTION(false, "should be overriden by child class");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::GetSupportsThreading(bool *aResult)
+{
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::FindIndexFromKey(nsMsgKey aMsgKey, bool aExpand, nsMsgViewIndex *aIndex)
+{
+  NS_ENSURE_ARG_POINTER(aIndex);
+
+  *aIndex = FindKey(aMsgKey, aExpand);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMsgDBView::FindIndexOfMsgHdr(nsIMsgDBHdr *aMsgHdr, bool aExpand, nsMsgViewIndex *aIndex)
+{
+  NS_ENSURE_ARG(aMsgHdr);
+  NS_ENSURE_ARG_POINTER(aIndex);
+
+  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
+  {
+    nsMsgViewIndex threadIndex = ThreadIndexOfMsgHdr(aMsgHdr);
+    if (threadIndex != nsMsgViewIndex_None)
+    {
+      if (aExpand && (m_flags[threadIndex] & nsMsgMessageFlags::Elided))
+        ExpandByIndex(threadIndex, nullptr);
+      *aIndex = FindHdr(aMsgHdr, threadIndex);
+    }
+    else
+      *aIndex = nsMsgViewIndex_None;
+  }
+  else
+    *aIndex = FindHdr(aMsgHdr);
+
+  return NS_OK;
+}
+
+static void getDateFormatPref( nsIPrefBranch* _prefBranch, const char* _prefLocalName, nsDateFormatSelector& _format )
+{
+  // read
+  int32_t nFormatSetting( 0 );
+  nsresult result = _prefBranch->GetIntPref( _prefLocalName, &nFormatSetting );
+  if ( NS_SUCCEEDED( result ) )
+  {
+    // translate
+    nsDateFormatSelector res( nFormatSetting );
+    // transfer if valid
+    if ( ( res >= kDateFormatNone ) && ( res <= kDateFormatWeekday ) )
+      _format = res;
+  }
+}
+
+nsresult nsMsgDBView::InitDisplayFormats()
+{
+  m_dateFormatDefault   = kDateFormatShort;
+  m_dateFormatThisWeek  = kDateFormatShort;
+  m_dateFormatToday     = kDateFormatNone;
+
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIPrefService> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv,rv);
+  nsCOMPtr<nsIPrefBranch> dateFormatPrefs;
+  rv = prefs->GetBranch("mail.ui.display.dateformat.", getter_AddRefs(dateFormatPrefs));
+  NS_ENSURE_SUCCESS(rv,rv);
+
+  getDateFormatPref( dateFormatPrefs, "default", m_dateFormatDefault );
+  getDateFormatPref( dateFormatPrefs, "thisweek", m_dateFormatThisWeek );
+  getDateFormatPref( dateFormatPrefs, "today", m_dateFormatToday );
+  return rv;
+}
+
+void nsMsgDBView::SetMRUTimeForFolder(nsIMsgFolder *folder)
+{
+  uint32_t seconds;
+  PRTime2Seconds(PR_Now(), &seconds);
+  nsAutoCString nowStr;
+  nowStr.AppendInt(seconds);
+  folder->SetStringProperty(MRU_TIME_PROPERTY, nowStr);
+}
+
+
+NS_IMPL_ISUPPORTS(nsMsgDBView::nsMsgViewHdrEnumerator, nsISimpleEnumerator)
+
+nsMsgDBView::nsMsgViewHdrEnumerator::nsMsgViewHdrEnumerator(nsMsgDBView *view)
+{
+  // we need to clone the view because the caller may clear the
+  // current view immediately. It also makes it easier to expand all
+  // if we're working on a copy.
+  nsCOMPtr<nsIMsgDBView> clonedView;
+  view->CloneDBView(nullptr, nullptr, nullptr, getter_AddRefs(clonedView));
+  m_view = static_cast<nsMsgDBView*>(clonedView.get());
+  // make sure we enumerate over collapsed threads by expanding all.
+  m_view->ExpandAll();
+  m_curHdrIndex = 0;
+}
+
+nsMsgDBView::nsMsgViewHdrEnumerator::~nsMsgViewHdrEnumerator()
+{
+  if (m_view)
+    m_view->Close();
+}
+
+NS_IMETHODIMP nsMsgDBView::nsMsgViewHdrEnumerator::GetNext(nsISupports **aItem)
+{
+  NS_ENSURE_ARG_POINTER(aItem);
+
+  if (m_curHdrIndex >= m_view->GetSize())
+    return NS_ERROR_FAILURE;
+
+  // Ignore dummy header. We won't have empty groups, so
+  // we know the view index is good.
+  if (m_view->m_flags[m_curHdrIndex] & MSG_VIEW_FLAG_DUMMY)
+    ++m_curHdrIndex;
+
+  nsCOMPtr<nsIMsgDBHdr> nextHdr;
+
+  nsresult rv = m_view->GetMsgHdrForViewIndex(m_curHdrIndex++, getter_AddRefs(nextHdr));
+  NS_IF_ADDREF(*aItem = nextHdr);
+  return rv;
+}
+
+NS_IMETHODIMP nsMsgDBView::nsMsgViewHdrEnumerator::HasMoreElements(bool *aResult)
+{
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = m_curHdrIndex < m_view->GetSize();
+  return NS_OK;
+}
+
+nsresult nsMsgDBView::GetViewEnumerator(nsISimpleEnumerator **enumerator)
+{
+  NS_IF_ADDREF(*enumerator = new nsMsgViewHdrEnumerator(this));
+  return (*enumerator) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
+}
+
+nsresult nsMsgDBView::GetDBForHeader(nsIMsgDBHdr *msgHdr, nsIMsgDatabase **db)
+{
+  nsCOMPtr<nsIMsgFolder> folder;
+  nsresult rv = msgHdr->GetFolder(getter_AddRefs(folder));
+  NS_ENSURE_SUCCESS(rv, rv);
+  return folder->GetMsgDatabase(db);
+}
+
+/**
+ * Determine whether junk commands should be enabled on this view.
+ * Junk commands are always enabled for mail. For nntp and rss, they
+ * may be selectively enabled using an inherited folder property.
+ *
+ * @param  aViewIndex  view index of the message to check
+ * @return             true if junk controls should be enabled
+ */
+bool nsMsgDBView::JunkControlsEnabled(nsMsgViewIndex aViewIndex)
+{
+  // For normal mail, junk commands are always enabled.
+  if (!(mIsNews || mIsRss || mIsXFVirtual))
+    return true;
+
+  // we need to check per message or folder
+  nsCOMPtr <nsIMsgFolder> folder = m_folder;
+  if (!folder && IsValidIndex(aViewIndex))
+    GetFolderForViewIndex(aViewIndex, getter_AddRefs(folder));
+  if (folder)
+  {
+    // Check if this is a mail message in search folders.
+    if (mIsXFVirtual)
+    {
+      nsCOMPtr <nsIMsgIncomingServer> server;
+      folder->GetServer(getter_AddRefs(server));
+      nsAutoCString type;
+      if (server)
+        server->GetType(type);
+      if (!(MsgLowerCaseEqualsLiteral(type, "nntp") || MsgLowerCaseEqualsLiteral(type, "rss")))
+        return true;
+    }
+
+    // For rss and news, check the inherited folder property.
+    nsAutoCString junkEnableOverride;
+    folder->GetInheritedStringProperty("dobayes.mailnews@mozilla.org#junk",
+                                       junkEnableOverride);
+    if (junkEnableOverride.EqualsLiteral("true"))
+      return true;
+  }
+
+  return false;
+}