From 50d0ebc6c898d3b1538f6e1d62868ac11f487a3e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Burak=20Kaan=20K=C3=B6se?= <bkaankose@outlook.com>
Date: Wed, 29 Jan 2025 16:12:10 +0100
Subject: [PATCH] Fixing remote highest mode seq checks for qresync and
 condstore synchronizers.

---
 .../ImapSync/CondstoreSynchronizer.cs         | 23 +++++++++----------
 .../ImapSynchronizationStrategyProvider.cs    |  2 +-
 .../ImapSync/QResyncSynchronizer.cs           |  4 +---
 3 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/Wino.Core/Synchronizers/ImapSync/CondstoreSynchronizer.cs b/Wino.Core/Synchronizers/ImapSync/CondstoreSynchronizer.cs
index b0028851..3f80a568 100644
--- a/Wino.Core/Synchronizers/ImapSync/CondstoreSynchronizer.cs
+++ b/Wino.Core/Synchronizers/ImapSync/CondstoreSynchronizer.cs
@@ -45,21 +45,20 @@ namespace Wino.Core.Synchronizers.ImapSync
                 await remoteFolder.OpenAsync(FolderAccess.ReadOnly, cancellationToken).ConfigureAwait(false);
 
                 var localHighestModSeq = (ulong)folder.HighestModeSeq;
-                var remoteHighestModSeq = remoteFolder.HighestModSeq;
 
                 bool isInitialSynchronization = localHighestModSeq == 0;
 
                 // There are some changes on new messages or flag changes.
                 // Deletions are tracked separately because some servers do not increase
                 // the MODSEQ value for deleted messages.
-                if (remoteHighestModSeq > localHighestModSeq)
+                if (remoteFolder.HighestModSeq > localHighestModSeq)
                 {
                     var changedUids = await GetChangedUidsAsync(client, folder, remoteFolder, synchronizer, cancellationToken).ConfigureAwait(false);
 
                     // Get locally exists mails for the returned UIDs.
                     downloadedMessageIds = await HandleChangedUIdsAsync(folder, synchronizer, remoteFolder, changedUids, cancellationToken).ConfigureAwait(false);
 
-                    folder.HighestModeSeq = (long)remoteHighestModSeq;
+                    folder.HighestModeSeq = unchecked((long)remoteFolder.HighestModSeq);
 
                     await FolderService.UpdateFolderAsync(folder).ConfigureAwait(false);
                 }
@@ -103,15 +102,15 @@ namespace Wino.Core.Synchronizers.ImapSync
 
             IList<UniqueId> changedUids = null;
 
-            // TODO: Temporarily disabled.
-            //if (winoClient.Capabilities.HasFlag(ImapCapabilities.Sort))
-            //{
-            //    changedUids = await remoteFolder.SortAsync(SearchQuery.ChangedSince(localHighestModSeq), [OrderBy.ReverseDate], cancellationToken).ConfigureAwait(false);
-            //}
-            //else
-            //{
-            //    changedUids = await remoteFolder.SearchAsync(SearchQuery.ChangedSince(localHighestModSeq), cancellationToken).ConfigureAwait(false);
-            //}
+            if (winoClient.Capabilities.HasFlag(ImapCapabilities.Sort))
+            {
+                // Highest mod seq must be greater than 0 for SORT.
+                changedUids = await remoteFolder.SortAsync(SearchQuery.ChangedSince(Math.Max(localHighestModSeq, 1)), [OrderBy.ReverseDate], cancellationToken).ConfigureAwait(false);
+            }
+            else
+            {
+                changedUids = await remoteFolder.SearchAsync(SearchQuery.ChangedSince(localHighestModSeq), cancellationToken).ConfigureAwait(false);
+            }
 
             changedUids = await remoteFolder.SearchAsync(SearchQuery.ChangedSince(localHighestModSeq), cancellationToken).ConfigureAwait(false);
 
diff --git a/Wino.Core/Synchronizers/ImapSync/ImapSynchronizationStrategyProvider.cs b/Wino.Core/Synchronizers/ImapSync/ImapSynchronizationStrategyProvider.cs
index b6fef92c..5959b749 100644
--- a/Wino.Core/Synchronizers/ImapSync/ImapSynchronizationStrategyProvider.cs
+++ b/Wino.Core/Synchronizers/ImapSync/ImapSynchronizationStrategyProvider.cs
@@ -22,7 +22,7 @@ namespace Wino.Core.Synchronizers.ImapSync
             if (client is not WinoImapClient winoImapClient)
                 throw new System.ArgumentException("Client must be of type WinoImapClient.", nameof(client));
 
-            // if (client.Capabilities.HasFlag(ImapCapabilities.QuickResync) && winoImapClient.IsQResyncEnabled) return _qResyncSynchronizer;
+            if (client.Capabilities.HasFlag(ImapCapabilities.QuickResync) && winoImapClient.IsQResyncEnabled) return _qResyncSynchronizer;
             if (client.Capabilities.HasFlag(ImapCapabilities.CondStore)) return _condstoreSynchronizer;
 
             return _uidBasedSynchronizer;
diff --git a/Wino.Core/Synchronizers/ImapSync/QResyncSynchronizer.cs b/Wino.Core/Synchronizers/ImapSync/QResyncSynchronizer.cs
index 00b1daf0..25cd813d 100644
--- a/Wino.Core/Synchronizers/ImapSync/QResyncSynchronizer.cs
+++ b/Wino.Core/Synchronizers/ImapSync/QResyncSynchronizer.cs
@@ -58,8 +58,6 @@ namespace Wino.Core.Synchronizers.ImapSync
                 }
 
                 // Perform QRESYNC synchronization.
-
-                var remoteHighestModSeq = remoteFolder.HighestModSeq;
                 var localHighestModSeq = (ulong)folder.HighestModeSeq;
 
                 remoteFolder.MessagesVanished += async (c, r) => await HandleMessageDeletedAsync(folder, r.UniqueIds).ConfigureAwait(false);
@@ -75,7 +73,7 @@ namespace Wino.Core.Synchronizers.ImapSync
                 downloadedMessageIds = await HandleChangedUIdsAsync(folder, synchronizer, remoteFolder, changedUids, cancellationToken).ConfigureAwait(false);
 
                 // Update the local folder with the new highest mod-seq and validity.
-                folder.HighestModeSeq = (long)remoteHighestModSeq;
+                folder.HighestModeSeq = unchecked((long)remoteFolder.HighestModSeq);
                 folder.UidValidity = remoteFolder.UidValidity;
 
                 await ManageUUIdBasedDeletedMessagesAsync(folder, remoteFolder, cancellationToken).ConfigureAwait(false);